description stringlengths 2.98k 3.35M | abstract stringlengths 94 10.6k | cpc int64 0 8 |
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to a PLL circuit and a digital signal reproducing apparatus in which the PLL circuit is used in a reproducing clock forming circuit.
2. Description of the Prior Art
Hitherto, when a digital signal is recorded onto a magnetic tape, an optical disc, or the like and the digital signal is reproduced, a PLL (Phase Locked Loop) circuit is used to form a reproducing clock synchronized with a reproduction signal. The PLL circuit is constructed by a VCO (Voltage Controlled Oscillator), a phase comparator, and a loop filter. In a digital VTR (Video Tape Recorder) using the PLL circuit, an RF signal of a waveform as shown in FIG. 6 is reproduced in a high speed reproducing mode.
In the high speed reproducing mode, since a pair of heads reproduce a plurality of tracks including tracks whose azimuths don't coincide, in other words, since the azimuths of the tracks to be reproduced are different, an interval at a low signal level occurs. It is, therefore, necessary to switch response characteristics of the PLL from those in a normal reproducing mode. Since the two kinds of response characteristics in the normal reproducing mode and the high speed reproducing mode can be set to predetermined time constants. In the high speed reproducing mode, since there is no preamble and reproduction data immediately exists, the time constant is set to be smaller than that in the normal reproducing mode in which a preamble interval exists and a response speed is made high, so that a larger amount of data can be obtained.
When switching the response characteristics (time constants) as mentioned above, in FIG. 1A, constants of a resistor R2 and a capacitor C1 constructing a loop filter have to be changed. A construction in FIG. 1A shows a part of the PLL, namely, only a loop filter arranged between a phase comparator 1 and a VCO 2. The connection between the phase comparator 1 and VCO 2 is called a balanced (differential) form. The balanced form has an advantage such that an in-phase component of noises during the generation of phase comparison signals is eliminated because of the form of the balanced signals and a construction which is strong against the noises can be obtained and a high sensitive VCO can be used.
When a bipolar transistor is used for switching the response characteristics of the PLL using the balanced form, since a base current flows from a bipolar transistor, a balance relation is broken, so that an FET (Field Effect Transistor) has conventionally been used. A simplest method of switching the two kinds of response characteristics (time constants) by using the FET is a method such that, as shown in FIG. 1B, two kinds of constants of the resistor R2 and capacitor C1 and a resistor R2' and a capacitor C1' are prepared and they are switched by using FETs 1 and 1'.
However, when the PLL is constructed by an IC, if a power source voltage of the IC is low, output currents flowing in the resistors R2 and R2' and capacitors C2 and C2' are equal to hundreds of μA!, so that it is difficult to perfectly switch such weak currents by the low power source voltage by the FET. This is because a potential difference which is applied between a gate and a source of the FET is so high to be a few volts and such an IC cannot be used in case of a circuit of the form as shown in FIG. 1B.
OBJECT OF THE INVENTION
It is, therefore, an object of the invention to provide a PLL of the balanced (differential) form, namely, a PLL circuit and a digital signal reproducing apparatus which can switch response characteristics, operate at a low power source voltage, and can reduce an electric power consumption.
SUMMARY OF THE INVENTION
According to the invention disclosed in claim 1, there is provided a PLL circuit comprising: a VCO; a phase comparator for comparing phases of output signals and input signals of the VCO; and a loop filter inserted between output terminals of the phase comparator and control signal input terminals of the VCO, wherein output signals of the loop filter are switched by switching a first time constant and a second time constant, and output signals of the phase comparator and the output signals of the loop filter in which a first time constant and a second time constant can be switched have a form of balance signals.
According to the invention disclosed in claim 2, there is provided a digital signal reproducing apparatus having a PLL circuit to which a reproduction signal from a recording medium is supplied and which forms a reproducing clock synchronized with the reproduction signal, wherein the PLL circuit is constructed by a VCO, a phase comparator for comparing phases of output signals and input signal of the VCO, and a loop filter inserted between output terminals of the phase comparator and control signal input terminals of the VCO, and output signals of the phase comparator and output signals of the loop filter in which the first and second time constants can be switched in accordance with a reproducing mode of the digital signal reproducing apparatus have a form of the balance signals.
A situation such that charging characteristics and discharging characteristics are different due to a difference of a conducting form of a transistor can be prevented, two kinds of time constants can be easily switched, and further, a deterioration of the characteristics of the PLL circuit can be prevented.
The above and other objects and features of the present invention will become apparent from the following detailed description and the appended claims with reference to the accompanying drawings
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1A and 1B are constructional diagrams of a prior art of a loop filter;
FIG. 2 is a block diagram of an example of a PLL to which the invention is applied;
FIGS. 3A to 3C are circuit diagrams of an example which is used for explanation of a loop filter according to the invention;
FIGS. 4A to 4C are circuit diagrams of the loop filter according to an embodiment of the invention;
FIG. 5 is a circuit diagram of a loop filter according to another embodiment of the invention;
FIG. 6 shows an RF waveform in a variable speed reproducing mode; and
FIG. 7 is a block diagram of an example of a magnetic recording and reproducing apparatus to which the PLL of the invention is applied.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
An embodiment according to the invention will now be described hereinbelow with reference to the drawings. In FIG. 2, an input signal processing circuit 12, a phase comparator 13, a VCO 15, and a clock output buffer 16 are constructed in a PLL-IC shown by a reference numeral 11. An input signal, for example, a reproduction digital signal from a magnetic tape is supplied from an input terminal t1. Processes such as a waveform shaping for extracting a leading edge and a trailing edge of an input signal and the like are performed in the input signal processing circuit 12 and the resultant processed signal is supplied to the phase comparator 13.
Output signals of the VCO 15 are extracted through the clock output buffer 16 to an output terminal t2 and are supplied to the phase comparator 13. The phase comparator 13 compares phases of the outputs of the VCO 15 and the input signals transmitted via the input signal processing circuit 12 and generates comparison outputs to terminals t3 and t4. The comparison outputs are supplied to control voltage input terminals t5 and t6 of the VCO 15 through a loop filter 14 constructed by external parts of the PLL-IC 11.
According to the embodiment, a signal which is inputted/outputted among circuit blocks constructing the PLL circuit mentioned above have a balanced (differential) form. According to the invention, it is at least necessary that a circuit section from the output terminals of the phase comparator 13 through the loop filter 14 to the control voltage input terminals of the VCO 15 has the form of balance signals.
FIGS. 3A to 3C show examples of a circuit construction of the loop filter 14 inserted between the phase comparator 13 and VCO 15 according to the embodiment of the invention. The loop filter 14 shown in FIG. 3A is constructed by a low-pass filter and response characteristics of the PLL can be changed by switching a time constant of the low-pass filter.
The loop filter 14 can be modified to a circuit construction shown in FIG. 3B. In the construction of FIG. 3B, capacitors C12 and C13 have a capacity that is twice as large as that of a capacitor C11 (C11×2=C12=C13). Further, even when resistors R13 and R14 have a resistance that is the half of a resistance of a resistor R12 (R12/2=R13=R14), a similar effect is derived. In FIG. 3B, since an electric potential at a connection point A of the capacitors C12 and C13 exerts no influence on the operation of the circuit, the loop filter can be further modified to a circuit shown in FIG. 3C.
FIG. 4A shows an embodiment of a circuit construction which realizes the switching of the time constant of the loop filter 14 by using the circuit construction of FIG. 3C. A resistor R21 is inserted between outputs of the phase comparator 13, thereby supplying output signals as balance (differential) signals to control voltage input terminals of the VCO 15. A resistor R22, capacitors C21 and C22, and a resistor R23 are serially connected between one output of the phase comparator 13 and the ground. A collector of a transistor Tr21 is connected to a connection point of the capacitors C21 and C22 and this connection point is connected to the ground through collector-emitter of the transistor Tr21. A control signal is supplied to a base of the transistor Tr21.
A resistor R24, capacitors C23 and C24, and a resistor R25 are serially connected between the other output of the phase comparator 13 and the ground. A collector of a transistor Tr22 is connected to a connection point of the capacitors C23 and C24 and this connection point is connected to the ground through collector-emitter of the transistor Tr22. A control signal is supplied to a base of the transistor Tr22. Since the control signals which are supplied to the transistors Tr21 and Tr22 are the same signal, the ON/OFF operations of the transistors Tr21 and Tr22 are certainly simultaneously performed.
When the control signal which is supplied to the base of the transistor Tr21 is at the high level, the transistor Tr21 is turned ON. The capacitor C22 and resistor R23 are short-circuited. Similarly, the control signal which is supplied to the base of the transistor Tr22 is also set to the high level, so that the transistor Tr22 is turned ON. The capacitor C24 and resistor R25 are short-circuited. FIG. 4B shows an equivalent circuit when the control signal is at the high level as mentioned above.
Values of resistors R26 and R27 and capacitors C25 and C26 shown in FIG. 4B are shown below.
R26=R22
R27=R24
C25=C21
C26=C23
When the control signal which is supplied to the base of the transistor Tr21 is at the low level, the transistor Tr21 is turned OFF. No current flows between the collector and the emitter of the transistor Tr21. Similarly, since the control signal which is supplied to the base of the transistor Tr22 is also set to the low level, the transistor Tr22 is turned OFF. No current flows between the collector and the emitter of the transistor Tr22. FIG. 4C shows an equivalent circuit when the control signal is set to the low level as mentioned above.
Values of resistors R28 and R29 and capacitors C27 and C28 shown in FIG. 4C are shown below.
R28=R22+R23
R29=R24+R25
C27=C21×C22/(C21+C22)
C28=C23×C24/(C23+C24)
FIG. 5 shows another embodiment of a circuit construction which realizes the switching of the time constant of the loop filter 14. A resistor R31 is inserted between the outputs of the phase comparator 13 and output signals are supplied as balance (differential) signals to control voltage input terminals of the VCO 15. A resistor R32 and a cappacitor C31 are serially connected between one output of the phase comparator 13 and the collector of a transistor Tr31. An emitter of the transistor Tr31 is connected to the ground. A resistor R33 and a capacitor C32 are serially connected between the other output of the phase comparator 13 and a collector of a transistor Tr32. An emitter of the transistor Tr32 is connected to the ground.
A resistor R34 and a capacitor C33 are connected between the collector of the transistor Tr31 and the collector of the transistor Tr32. Control signals are supplied to bases of the transistors Tr31 and Tr32.
Values of the resistor R34 and capacitor C33 shown in FIG. 5 are shown below.
R34=R23+R25
C33=C22×C24/2
As mentioned above, by properly selecting the values of the resistors R22 to R25 and capacitors C21 to C24 shown in FIG. 4A or the values of the resistors R32 to R34 and capacitors C31 to C33 shown in FIG. 5, two kinds of desired time constants can be realized.
As mentioned above, according to the conventional method, when a bipolar transistor is used, a base current of hundreds of μA! flows from the emitter of the bipolar transistor in the ON state, so that a balance of the balance signals is broken. The bipolar transistor, consequently, cannot be used. By using the circuit construction shown in the embodiment, however, no base current flows to the resistors and capacitors, namely, a balance of the balance signals is not broken. Thus, the transistor can be used.
A magnetic recording and reproducing apparatus using a PLL according to the invention will now be described with reference to FIG. 7. In FIG. 7, reference numerals 21A and 21B denote a pair of heads which face on a rotary drum at an interval of 180°. A magnetic tape 22 is wrapped around the drum at an angle which is slightly larger than 180°. The heads 21A and 21B alternately trace the magnetic tape 22. A signal is transmitted and received to/from the heads 21A and 21B through a rotary transformer 23. For example, the rotary transformer 23 has a construction such that a rotor yoke which is rotated integratedly with the drum and a fixed stator yoke face each other and a winding is arranged in a groove formed in each yoke.
A digital video signal, digital audio signals, and a subcode to be recorded are supplied to an input terminal 24. In a source coding circuit 25, t hose signals are compression encoded and are also subjected to a coding process of an error correction code. An output signal of the source coding circuit 25 is supplied to a channel coding circuit 26. The channel coding circuit 26 digitally modulates a recording digital signal. For example, by mapping data of 24 bits into data of 25 bits, a recording digital signal whose DC component is reduced is obtained.
An output signal of the channel coding circuit 26 is supplied to a recording amplifier 27. A recording/reproduction change-over switch 28A is constructed by an output terminal r and a ground terminal p of the recording amplifier 27 . The switch 28A is controlled by a recording/reproduction switching signal formed by the channel coding circuit 26. Namely, upon recording, the terminal r of the switch 28A is selected. Upon reproduction, the terminal p connected to the ground is selected. An output signal of the recording amplifier 27 is supplied to the heads 21A and 21B through the terminal r of the switch 28A and the rotary transformer 23 and is recorded onto the magnetic tape 22. Upon reproduction, the terminal p is selected and no recording signal is supplied to the heads 21A and 21B.
The signals reproduced by the heads 21A and 21B are supplied to a reproducing amplifier 31 through the rotary transformer 23 and a recording/reproduction change-over switch 28B. In a manner similar to the switch 28A, the switch 28B has a recording side terminal r and a reproduction side terminal p and is controlled by the recording/reproduction switching signal from the channel coding circuit 26. An output signal of the reproducing amplifier 31 is supplied to a channel decoding circuit 32. The channel decoding circuit 32 executes processes opposite to the processes executed by the channel coding circuit 26 of a recording system. A source decoding circuit 33 is connected to the channel coding circuit 32. The source decoding circuit 33 executes processes opposite to the processes executed by the source coding circuit 25 of the recording system. A reproduction video signal, reproduction audio signals, and a reproduction subcode are fetched to an output terminal 34 of the source decoding circuit 33.
A clock reproduced by a PLL-IC 11 is used for a decoding process of the channel decoding circuit 32. A TBC (time base compensator) is included in the channel decoding circuit 32. An output signal in which a time base fluctuation of the reproduction signal was eliminated is generated from the TBC. The clock reproduced by the PLL-IC 11 specifies a timing for a signal process up to the input side (writing side) of the TBC. A timing after the output side (reading side) of the TBC is specified on the basis of a clock of a fixed frequency.
A signal transmitted through a switch 35 is supplied as a reference signal to the PLL-IC 11. The switch 35 has an input terminal R connected to the output of the channel coding circuit 26 and an input terminal P connected to the output of the reproducing amplifier. The switch 35 is controlled by the control signals to control the recording/reproduction changeover switches 28A and 28B. Namely, in a manner similar to the switches 28A and 28B, the switch 35 selects the input terminal R upon recording and selects the input terminal P upon reproduction.
According to the invention, the operation in which the response characteristics of the PLL having therein the circuit is switched on the basis of a balance form and which is conventionally difficult can be performed. Since the invention is also effective in a low power source voltage circuit, it is also remarkably effective to reduce an electric power consumption of the circuit.
The present invention is not limited to the foregoing embodiment but many modifications and variations are possible within the spirit and scope of the appended claims of the invention. | A PLL circuit which is used as a reproducing clock forming circuit of a digital signal reproducing apparatus. The PLL circuit is strong against noises and has stable characteristics. Comparison outputs of a phase comparator 3 are outputted in a form of balance (differential) signals and are supplied to a loop filer 4. Output signals of the loop filter 4 are supplied to control voltage input terminals of a VCO 5 in a form of the balance signals. In-phase components of the noises included in control voltages can be cancelled. Time constants of the loop filter can be switched by bipolar transistors Tr31 and Tr32. A balance of the balance signals is not broken by base currents of the transistors Tr31 and Tr32. | 7 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates generally to semiconductor wafer fabrication, and more particularly to semiconductor wafer scrubbing equipment.
2. Description of the Related Art
As is well known, semiconductor devices are fabricated from semiconductor wafers, which are subjected to numerous processing operations. These operations include, for example, impurity implants, gate oxide generation, inter-metal oxide depositions, metallization depositions, photolithography pattering, etching operations, chemical mechanical polishing (CMP), etc. Although these processes are performed in ultra clean environments, the very nature of many of the process operations is to blame for the generation of surface particles and residues. For instance, when CMP operations are performed, a film of particles and/or metal contaminants are commonly left behind.
Because surface particles can detrimentally impact the performance of an integrated circuit device, wafer cleaning operations have become a standard procedural requirement after certain process steps. Although cleaning operations are rather procedural, the equipment and chemicals implemented to perform the actual cleaning are highly specialized. This specialization is important because each wafer, being at different stages of fabrication, represents a significant investment in terms of raw materials, equipment fabrication time, and associated research and development.
To perform the cleaning operations in an automated manner, fabrication labs employ cleaning systems. The cleaning systems typically include one or more brush boxes in which wafers are scrubbed. Each brush box includes a pair of brushes, such that each brush scrubs a respective side of a wafer. To enhance the cleaning ability of such brush boxes, it is common practice to deliver cleaning fluids through the brush (TTB). TTB fluid delivery is accomplished by implementing brush cores that have a plurality of holes that allow fluids being fed into the brush core at a particular pressure to be released into an outer brush surface. The outer brush surface is made out of a very porous and soft material so that direct contact with the delicate surface of a wafer does not cause scratches or other damage. Typically, the outer brush surface is a made out of polyvinyl alcohol (PVA) foam. Although, other materials such as nylon, mohair or a mandrel wrapped with a polishing pad material can be used.
As semiconductor design and performance requirements continue increase, cleaning engineers are also challenged to improve their associated processes. To meet these demands, the same cleaning equipment is now being used to perform operations other than basic de-ionized (DI) water cleaning. Such operations include the application of sophisticated chemicals TTB to remove particulates and/or to etch precision amounts of materials from the surfaces of a wafer. Although much research and development goes into the design of cleaning and etching chemicals, the effectiveness of such chemicals is only as good as their delivery and application onto the surface of a wafer.
Recent research of conventional brush core technology has uncovered non-uniformities in the application of the chemicals onto the surface of wafers. The research indicates that although chemicals are being flushed out of the brush cores and onto the wafer surfaces, the applied chemicals do exit the holes of the brush core at the same rate over the length of a core. For instance, chemicals are generally supplied to an internal bore of a brush core from one end of the brush core at a given pressure. Ideally, the chemicals are expected to flow through the bore and drip or flow out of the core equally from all of the brush core holes (e.g., the same amount drips out each of holes all along the brush core). Unfortunately, research shows that chemicals are not dripping out of all of the holes at the same or substantially the same rate. In fact, much of the research indicates that the brush core holes near the chemical receiving end drip out chemicals at a substantially faster rate than holes at the opposite side of the chemical receiving end.
Because traditional cleaning typically only included the application of DI water and/or ammonia based chemicals, the uneven application of these fluids through the brush core did not in many cases detrimentally impact cleaning performance. However, because most cleaning systems are now required to also apply engineered chemicals, such as hydrofluoric acid (HF) containing etch chemicals, any uneven application will have a severe impact on the wafer being processed. For instance, if more HF is applied to one part of the wafer and less is applied to another part of the wafer, the surface of the processed wafer may exhibit performance impacting etch variations due to experienced chemical concentration variations.
FIG. 1A provides a simplified diagram 10 of a prior art brush core 12 having a plurality of holes 12 a . The brush core 12 has a center bore 12 b which is configured to receive fluids from a fluid input 16 at one end of the brush core 12 . The brush core 12 is shown having a brush 14 mounted thereon to illustrate that fluid that enters the bore 12 b exits the holes 12 a soaks the brush 14 that is designed to contact a wafer. This simplistic diagram also illustrates fluid flow lines 18 a and 18 b , in which fluid lines 18 a illustrate that more fluid tends to flow out of holes 12 a near the fluid input than at the opposite end. It is believed that this occurs because chemicals are either not applied to the brush core 12 at a sufficient pressure or the holes 12 are too large and/or are improperly arranged and thus allow gravity to pull more fluid out of the brush core 12 near the fluid input 16 than at the opposite end.
Some of these prior art brush cores 12 have a center bore 12 b that is about 0.36 inch in diameter or larger and holes 12 a that are about 0.13 inch in diameter or larger. To compensate for the larger size of these dimensions and to attempt to prevent the uneven delivery of fluids, cleaning systems need to deliver fluids to the brush cores 12 at higher pressures. These higher pressures range between 30 to 35 PSI or higher. However, the application of higher pressures require the cleaning system to have access to facilities and associated equipment that can deliver the desired controlled pressures at all times. However, cleaning systems are installed in clean rooms around the world having different facilities which may or may not be able to deliver the recommended pressures. Additionally, the holes 12 a of most prior art brush cores 12 are arranged such that one hole 12 a ′ is directly opposite of another hole 12 a ′. This arrangement is also believed to contribute to the higher outflow of fluids near the fluid input 16 than at the opposite end.
In view of the foregoing, there is a need for improved brush core designs that enable controlled amounts of fluid to be evenly delivered and distributed over the surface areas of a brush core.
SUMMARY OF THE INVENTION
Broadly speaking, the present invention fills these needs by providing a brush core for use in scrubbing substrates. The substrate can be any substrate that may need to undergo a scrubbing operation to complete a cleaning operation, etching operation, or other preparation. For instance, the substrate can be a semiconductor wafer, a disk, or any other type of work piece that will benefit from a brush core that can deliver uniform controlled amounts of fluid through the brush along an entire length of the brush core. It should be appreciated that the present invention can be implemented in numerous ways, including as a process, an apparatus, a system, a device, or a method. Several inventive embodiments of the present invention are described below.
In one embodiment, a brush core for use in substrate scrubbing is disclosed. The brush core is defined by a tubular core extending between a first end and a second end. A bore is defined through a middle of the tubular core. A first and second plurality of holes are provided. Each hole of the first and second plurality of holes is defined through the tubular core to define a path to the bore. The first plurality of holes is defined along a first line that extends between the first end and the second end and the second plurality of holes is defined along a second line that extends between the first end and the second end. The first line and the second line are repeated around the tubular core and the first line and the second line alternate around the tubular core, and the holes of the first plurality of holes are offset relative to the holes of the second plurality of holes.
In another embodiment, a brush core is disclosed. The brush core is defined by a tubular core having a length that extends between a first end and a second end. The first end has an opening into a bore that is defined through a middle of the tubular core and extends along an inner length of the tubular core. A first plurality of holes are oriented along a plurality of first lines that extend in the direction of the length of the tubular core, and each of the first plurality of holes define paths to the bore of the tubular core. A second plurality of holes are oriented along a plurality of second lines that extend in the direction of the length of the tubular core, and each of the second plurality of holes define paths to the core of the tubular core. The plurality of first lines and the plurality of second lines alternate and the holes of the first and second plurality of holes are equally spaced apart. The holes of the second plurality of holes are offset relative to the holes of the first plurality of holes.
In yet a further embodiment, a method of making a brush core is disclosed. The method includes providing a tubular core having a length that is configured to extend over a substrate. A bore is defined through a center of the tubular core. A first plurality of holes oriented along a plurality of first lines that extend in the direction of the length of the tubular core is defined. Each of the first plurality of holes is configured to establish paths to the bore of the tubular core. A second plurality of holes oriented along a plurality of second lines that extend in the direction of the length of the tubular core is defined. Each of the second plurality of holes is configured to establish paths to the core of the tubular core. The defined first plurality of holes are configured to be offset from the defined second plurality of holes.
Advantageously, the embodiments of the present invention provide brush cores for delivering a uniform fluid distribution throughout the core. The uniform fluid distribution is achieved by designing specially placed and sized holes into the brush core. The holes define paths to a specially designed center bore, which is configured and sized to quickly pressurize the bore such that the delivered fluid exits the plurality of holes at about the same rate. Achieving this substantial even outflow of fluid from the core along the entire length of the brush core ensures that the outer brush receives equal amounts of fluids during an application process. As can be appreciated, even outflow of fluids is especially important when the fluids are engineered chemicals, such as etchants, that are designed to remove certain material particles, films, or layers.
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
The present invention will be readily understood by the following detailed description in conjunction with the accompanying drawings, and like reference numerals designate like structural elements.
FIG. 1A provides a simplified diagram of a prior art brush core having a plurality of holes.
FIG. 1B shows a wafer cleaning station of the present invention that may be controlled in an automated way by a cleaning control station.
FIG. 1C shows a more detailed schematic of an exemplary wafer cleaning station, in accordance with one embodiment of the present invention.
FIG. 2A illustrates a simplified three-dimensional diagram of a pair of brushes scrubbing a top surface and a bottom surface of a wafer, in accordance with one embodiment of the present invention.
FIGS. 2B and 2C illustrate cross-sectional views of two different orientations for scrubbing a wafer, in accordance with one embodiment of the present invention.
FIG. 3 illustrates a three-dimensional view of a brush core, in accordance with one embodiment of the present invention.
FIGS. 4A through 4C illustrate alternative channel geometries for a tubular core, in accordance with one embodiment of the present invention.
FIG. 5A shows a cross-sectional view of the brush core, in accordance with one embodiment of the present invention.
FIGS. 5B and 5C illustrate cross-sectional views A—A and B—B along a brush core, in accordance with one embodiment of the present invention.
FIG. 6 illustrates a simplified diagram of a plurality of channels having a plurality of holes, in accordance with one embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
An invention is described for a brush core for use in scrubbing substrates. The substrate can be any substrate that may need to undergo a scrubbing operation to complete a cleaning operation, etching operation, or other preparation. It will be obvious, 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 process operations have not been described in detail in order not to unnecessarily obscure the present invention.
FIG. 1B shows a wafer cleaning station 100 of the present invention that may be controlled in an automated way by a cleaning control station 102 . The wafer cleaning station 100 includes a sender station 104 , a cleaning stage 106 , a spin-rinse and dry (SRD) station 108 , and a receiver station 110 . As a broad overview of the cleaning process, semiconductor wafers are initially placed into the sender station 104 . The sender station 104 then delivers a wafer (one-at-a-time) to the cleaning stage 106 . In one embodiment, the cleaning stage 106 is divided into a first cleaning stage 106 a and a second cleaning stage 106 b , although having just one cleaning stage 106 will also work. After passing through the cleaning stage 106 , the wafer is passed through an exit spray in order to remove the cleaning fluids and any contaminants. The SRD station 108 dries the wafer and then it is delivered to the receiver station 110 for temporary storage.
FIG. 1C shows a more detailed schematic of an exemplary wafer cleaning station 100 . Both the sender station 104 and the receiving station 110 are preferably adapted to receive a cassette containing a number of wafers. The first and second cleaning stages 106 a and 106 b preferably include a set of PVA brushes 120 that are very soft and porous. As will be described below, the brushes 120 are mounted on brush cores 200 of the present invention. As is well known, the brushes 120 are capable of scrubbing the wafer clean without damaging the delicate surface.
FIG. 2A illustrates a simplified three-dimensional diagram of a pair of brushes 120 a and 120 b for scrubbing a top surface and a bottom surface, respectively, of a wafer 130 . Typically, the wafer 130 is caused to rotate in a particular direction while the brushes 120 rotate around an axis of rotation while the surface of the brushes 120 are in contact with the surfaces of the wafer 130 . The brushes 120 a and 120 b are mounted on brush cores 200 a and 200 b . The brush cores 200 are configured to have at one end, a fluid inlet 201 which connects to tubing 202 . The tubing 202 will thus supply the desired fluids to a bore 270 within the brush core 200 . The brush core 200 , as will be described in greater detail below, will have a plurality of holes 260 that will allow the fluids provided into the bore 270 to uniformly exit the brush core 200 (i.e., therefore evenly supplying the desired fluid to the brushes 120 ).
FIGS. 2B and 2C illustrate cross-sectional views of two different orientations for scrubbing a wafer 130 , in accordance with one embodiment of the present invention. As shown in FIG. 2B, the wafer is held horizontally while a top brush 120 a scrubs the top surface of the wafer 130 , and a bottom brush 120 b scrubs the bottom surface of the wafer 130 . As mentioned above, the wafer 130 is configured to rotate (using rollers not shown) at the same time that the brushes 120 rotate to ensure that the entire surface area of the wafer is properly scrubbed to remove contaminants or etch the surface to a desired degree. Thus, FIG. 2B illustrates a horizontal wafer scrubber 100 b.
In contrast, FIG. 2C illustrates a vertical wafer scrubber 100 c in which the wafer 130 is scrubbed while in a vertical position. Typically, the wafer 130 sits on a pair of rollers of the scrubber 100 c . The brushes 120 are configured to rotate in a desired direction such that both sides of the wafer 130 are evenly scrubbed, using an equal and opposite pressure on each side of the wafer 130 . For more information on vertical wafer scrubbing, reference may be made to U.S. Pat. No. 5,875,507, having inventors Stephens et al., entitled “Wafer Cleaning Apparatus,” which is hereby incorporated reference.
FIG. 3 illustrates a three-dimensional view of a brush core 200 , in accordance with one embodiment of the present invention. The brush core 200 is defined by a tubular core 250 that extends between a first end 253 and a second end 251 . The tubular core is configured to include, in one embodiment, a plurality of channels 252 which are recessed into the surface of the tubular core 250 . One feature of the present invention is to ensure that an even distribution of fluid is provided throughout the brush core 200 . For instance, a fluid source 263 supplies fluid by way of tubing (not shown) into the bore 270 of the tubular core 250 such that the fluid is evenly distributed to each of the plurality of holes 260 . In a preferred orientation, the plurality of holes 260 of one channel 252 are arranged in an offset configuration relative to holes defined in an adjacent respective channel 252 .
For instance, one channel may include a first plurality of holes 260 aligned along a first line across the length of the tubular core 250 , and the next channel that is adjacent to the first channel will have its plurality of holes 260 defined along a second line across the length of the tubular core 250 . However, the holes 260 defined in the adjacent channel 252 will be offset relative to the holes of its respective adjacent channel 252 . In a preferred embodiment, the holes 260 will be evenly spaced apart and defined along the channel 252 that traverses the length of the tubular core 250 . As shown, the holes 260 of the adjacent channel are shifted by an amount that is equal to about half of the separation distance between the holes of the first channel. In one embodiment, the offset can be any amount so long as some offset is provided. In this manner, any fluid provided by the fluid source 263 into the bore that is defined through the tubular core 250 will evenly distribute into the bore and emanate out from all of the plurality of holes defined through the tubular core 250 .
In this example, the first end 253 of the brush core 200 includes a threaded insert 262 and an extension 264 . This threaded insert 262 and extension 264 are configured to provide a way to connect up to an appropriate fluid line which will deliver fluids (e.g., chemicals, DI water, or mixtures of fluids) to the bore 270 of the tubular core 250 . The second end 251 of the brush core 200 includes a connection hole 256 for holding the second end of the brush core 200 in place when it is installed into a suitable brush box mechanism. Also shown are a plurality of locking pin holes 254 for engaging the tubular core 250 and enabling the application of a torque rotation to the brush core when the brush box requires the brush core to rotate about a defined axis.
FIGS. 4A through 4C illustrate alternative channel geometries for the tubular core 250 , in accordance with one embodiment of the present invention. As shown in FIG. 4A, a radial channel 252 can be defined into the tubular core 250 so that when the brush 120 is mounted on the brush core 200 , any fluid provided through the plurality of holes 260 can be distributed along the channel and the length of the tubular core 250 . FIG. 4B illustrates an alternative embodiment of the channel 252 a in which a slotted channel is provided to achieve the distribution of the fluids along the length of the tubular core 250 . In certain embodiments, it may be desired to eliminate the channel altogether as shown in FIG. 4C, and rely upon the very porous nature of the PVA brush which will absorb and evenly distribute the fluids throughout the brush. It should be understood that the actual shape or geometry of the channel can be varied or eliminated altogether if desired, for the particular application.
FIG. 5A shows a cross-sectional view of the brush core 200 , in accordance with one embodiment of the present invention. As shown in this example, the brush core 200 will include a bore 270 which is defined along an inner length of the tubular core 250 . The plurality of holes 260 illustrated along the top of the cross section are shown to be offset relative to the plurality of holes 260 defined along the bottom of the cross-sectional view. This offset design is configured to allow the even distribution of a fluid flow through the entire length of the bore 270 , and thus allow an equal outflow of the fluid flow through each of the plurality of holes 260 . That is, the present design is configured to allow a fluid flow having a reduced pressure to rapidly fill the bore 270 and reach equilibrium such that an equal flow of fluid will emanate from the plurality of holes 260 around the entire brush core 200 . Thus, holes such as 260 a defined near the first end 253 of the brush core 200 will exhibit about the same outflow of fluids as holes such as 260 b defined at the second end 251 of the brush core 200 .
FIGS. 5B and 5C illustrate cross-sectional views 5 B— 5 B and 5 C— 5 C along the brush core 200 , in accordance with one embodiment of the present invention. In this example, FIG. 5B illustrates the cross-sectional view of cross section 5 B— 5 B, and shows how the holes 260 are arranged around the tubular core 250 . In this example, holes are defined around the tubular core 250 at 12 o'clock, 2 o'clock, 4 o'clock, 6 o'clock, 8 o'clock, and 10 o'clock. However, at cross section 5 B— 5 B, only holes 260 at 12 o'clock, 4 o'clock, and 8 o'clock, are exposed to the fluid flow that travels down the bore 270 .
Because of the offset nature of the plurality of holes 260 that are defined along lines of the tubular core 250 , a cross-sectional view at 5 C— 5 C shown in FIG. 5C, illustrates that the holes at 2 o'clock, 6 o'clock, and 10 o'clock are now exposed to the fluid flow. In a preferred embodiment, the bore 270 will have a diameter ranging between about 0.060 inch and about 0.35 inch, and more preferably, between about 0.125 inch and about 0.30 inch, and most preferably at about 0.25 inch. It should be noted that the diameter of the bore 270 is substantially smaller than that typically used or suggested for brush cores of the prior art. By reducing the diameter of the bore 270 to such a reduced diameter, it has been tested that the fluid flow that enters the bore 270 will rapidly fill the volume of the bore 270 within the brush core 250 .
Because the volume within the bore 270 is rapidly filled, the bore 270 will be pressurized rapidly and the fluid will be ready to quickly outflow through the plurality of holes 260 all the way around the surface of the tubular core 250 . In this preferred embodiment, each of the plurality of holes 260 should have a diameter ranging between about 0.005 inch and about 0.092 inch, and most preferably, about 0.050 inch. It should be noted that the diameter of each of the plurality of holes 260 is also substantially reduced, which is configured in conjunction with the reduced bore 270 diameter to distribute any fluid flow delivered to the brush core 200 in a more even and distributed manner throughout the entire length of the brush core 200 . As discussed above, this is a substantial improvement in the art considering that the TTB fluid delivery is now being used to deliver sophisticated chemicals that are designed to alter the surface materials on a given substrate. For example, when chemistries including HF are applied to semiconductor wafer surfaces in an effort to etch certain material layers or films, an uneven application of such chemicals can cause surface damaging surface variations.
Continuing with the preferred design characteristics of a brush core 200 , when the brush core 200 is designed for a 300 mm wafer scrubbing application, the brush core may have six channels 252 around the tubular core 250 . Of course, more or less channels may be used (e.g., ranging between 2 and 12 channels). The total length L A of the exemplary brush core 200 is about 14 inches, and the brush 120 will thus have a length L B of about 13 inches. In this embodiment, the length L C of the channel 252 will be about 11 inches. Again, it should be understood that the length of the brush core 200 can vary and the number of holes within the channels 252 can also vary.
FIG. 6 illustrates a simplified diagram of a plurality of channels 252 having a plurality of holes 260 , in accordance with one embodiment of the present invention. In the case where six channels are provided, a channel will be provided at 12 o'clock, 2 o'clock, 4 o'clock, 6 o'clock, 8 o'clock, and 10 o'clock. As shown, the orientation of the plurality of holes 260 along the channels for 12 o'clock, 4 o'clock, and 8 o'clock begin at the same location of their respective channel 252 . Each of the plurality of holes 260 are separated by a separation distance S. In one embodiment, the separation distance is about 1.26 inch.
The separation distance S is selected such that an even spacing can be distributed along the distance of a selected channel. Thus, if the channel is longer or shorter, the separation S will be modified to meet the desired length of a given channel. In the exemplary embodiment of the present invention, the channel length is about 11 inches, and therefore the separation between each of the plurality of holes 260 is as described above about 1.26 inch. The holes in the adjacent channels 252 defined at 2 o'clock, 6 o'clock, and 10 o'clock, are offset relative to the holes of the first plurality of channels defined at 12 o'clock, 4 o'clock, and 8 o'clock.
This offset is preferably about half the distance of the separation parameter S. As pictorially illustrated, the offset between the channel of 12 o'clock and 2 o'clock is defined by an offset separation (OS) of about 0.63 inch. It should be understood that these parameters are only exemplary in nature and may be modified so long as some offset orientation is maintained to ensure even distribution of a fluid that may be provided into the bore 270 .
It is again noted that the brush core of the present invention can be modified for use in scrubbing any number of substrate types, for example, semiconductor wafers, hard drive discs, flat panel displays, and the like. Additionally, the brush core can be modified for substrate scrubbing applications of any size, for example, 100 mm wafers, 200 mm wafers, 300 mm wafers, larger wafers, small hard disks, etc. It should also be noted that any number of fluids can be delivered through the brush (TTB), for example, DI water, ammonia containing chemical mixtures, HF containing chemical mixtures, surfactant containing chemical mixtures, and many other variations.
For more information on wafer scrubbing brush technology, reference can be made to U.S. Pat. No. 5,806,126, having inventors de Larios et al., entitled “Apparatus For A Brush Assembly,” and U.S. patent application No. 09/112,666, having inventors Vail et al., entitled “Brush Interflow Distributor.” This U.S. Patent and U.S. Patent Application are hereby incorporated by reference.
For additional information on wafer preparing systems and techniques, reference may be made to commonly owned U.S. patent application Nos. (1) 08/792,093, filed Jan. 31, 1997now U.S. Pat. No. 5,858,109, entitled “Method And Apparatus For Cleaning Of Semiconductor Substrates Using Standard Clean 1 (SC1),” (2) 08/542,531, filed Oct. 13, 1995 now U.S. Pat. No. 5,806,128, entitled “Method and Apparatus for Chemical Delivery Through the Brush,” and (3) 09/277,712, filed Mar. 26, 1999, entitled “Pressure Fluctuation Dampening System.” All three U.S. patent applications are hereby incorporated by reference.
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. | A brush core and the method for making a brush core for use in substrate scrubbing are provided. The substrate can be any substrate that may need to undergo a scrubbing operation to complete a cleaning operation, etching operation, or other preparation. For instance, the substrate can be a semiconductor wafer, a disk, or any other type of work piece that will benefit from a brush core that can deliver uniform controlled amounts of fluid through the brush along an entire length of the brush core. The brush core is defined by a tubular core having a length that extends between a first end and a second end. The first end has an opening into a bore that is defined through a middle of the tubular core and extends along an inner length of the tubular core. A first plurality of holes are oriented along a plurality of first lines that extend in the direction of the length of the tubular core, and each of the first plurality of holes define paths to the bore of the tubular core. A second plurality of holes are oriented along a plurality of second lines that extend in the direction of the length of the tubular core, and each of the second plurality of holes define paths to the core of the tubular core. The plurality of first lines and the plurality of second lines alternate and the holes of the first and second plurality of holes are equally spaced apart. The holes of the second plurality of holes are offset relative to the holes of the first plurality of holes. | 7 |
CROSS-REFERENCES TO RELATED APPLICATIONS
The present application is a continuation of U.S. nonprovisional application Ser. No. 12/947,777, filed on Nov. 16, 2010, now U.S. Pat. No. 8,257,492, which claims priority to U.S. Ser. No. 61/374,202, filed Aug. 16, 2010, and Taiwanese Patent Application No. 098138830 filed on Nov. 16, 2009, commonly assigned, and hereby incorporated by reference herein.
FIELD OF THE INVENTION
The present invention relates to methods for purifying metallurgical grade silicon suitable for use in manufacturing solar cells.
BACKGROUND OF THE INVENTION
Silicon used for manufacturing solar cells is produced commonly by the so-called Siemens method. The Siemens method is well-established, and is commonly used to manufacture solar cells. In the Siemens process, silgrain (>99.6% purity) is used. Silgrain is then reacted with hydrochloric acid in the presence of a copper catalyst. The main product obtained is trichlorosilane (SiHCl3), which is purified through fractional distillation. The separated SiHCl3 is decomposed and reduced at high temperature on high-purity silicon rods. For each mole Si converted to polysilicon, 3 to 4 moles of SiCl4 is produced, binding large amounts of chlorine and valuable silicon. The resulting polysilicon has typically an impurity level of 10-9. The Siemens method produces high quality silicon. However, the Siemens method is not well suited to meet the dramatic increase in demand over the past few years for silicon at competitive prices. In addition, it involves dangerous raw materials such as HCl, SiHCl3, and H2 during the manufacturing process and produces a poisonous by-product, SiCl4. The Siemens method is dangerous, and it is hazardous to personnel and the environment.
Another purification method is disclosed in Japanese Patent No. 3205352 (JP352), the teachings of which are incorporated herein by reference. JP 352 method involves removing phosphorous by high temperature electron beams, removing impurity with directional cooling, adding water and gases to remove boron carbide during plasma irradiation, and removing impurity with directional cooling again. Each of these steps is performed sequentially. Although JP352 uses a simple structure to perform silicon purification, the simplicity of the design appears to result in various purification steps interfering with each other, which compromises the purification process.
A more cost-effective method for purifying metallurgical silicon is needed to meet the increasing demand for purified silicon.
SUMMARY OF THE INVENTION
The conventional manufacturing methods are sufficient in terms of being capable of producing silicon with the purity level required for manufacturing solar cells. However, they have inherent safety and environmental problems that are not easy to eliminate. In addition, initial and ongoing manufacturing costs of the methods are high, and they are not very flexible.
The present invention improves upon the conventional apparatus and method used for manufacturing single-crystal silicon. The present invention is able to mass produce solar-grade silicon (or polysilicon) while providing manufacturing flexibility and a competitive price.
Embodiments of the present invention include performing one or more of the following purifying processes for metallurgical grade silicon (or metallurgical silicon):
Independent Gas Provision: An independent supply tube supplies highly pressurized O2 gas towards H2 supplied by the plasma arc heater to the center of the surface of the silicon melt in the crucible so as to generate water vapor (H2O). The resulting water vapor is injected into the silicon melt as a result of the high-pressure ejection of O2, thereby providing the silicon melt with the water vapor that is needed to remove impurities.
Providing Intermittent Heating and Gas: Irradiation of the silicon melt in the crucible is intermittently performed by the plasma arc heater, so that the temperature at the surface of the silicon melt in the crucible is heated to a reproducible temperature gradient, e.g., hotter temperature at the middle of the silicon melt than at the outer portion that contacts the crucible. This in turn forms a temperature distribution across the silicon melt in the crucible, preventing the crucible from melting and providing stable and uniform conditions for metallurgical silicon purification. In addition, purifying gases for forming the water vapor are provided intermittently to avoid a rise in pressure caused by continuous provision of the water vapor, thus providing a safe and stable process environment for purifying metallurgical silicon.
Addition of Chemicals: Chemicals such as Ca, Si and Mg are added to the silicon raw material to react with the impurities therein, and the resulting compounds have relative densities lower than metallurgical silicon, which facilitates removal of the impurities. In an implementation, a method includes adding soluble chemicals, whose vitreous structures may be network modifiers including, for example, calcium chloride (CaCl2) and magnesium chloride (MgCl2), and network formers including, for example, sodium metasilicate (Na2SiO3). These soluble chemicals contact or blend with the impurities in the silicon raw material to form slag which floats up to the silicon melt surface and may be easily evaporated.
Silicon Melt Mixing: By ejecting purifying gases with high pressure via the supply tube towards the surface of the silicon melt in the crucible at the same time that H2O is provided to the silicon melt, the stream of high-pressure purifying gases forms a dimple on the silicon melt surface, thereby increasing the contact area for H2O. Meanwhile, circulation within the silicon melt in the crucible is facilitated due to heat convection resulting from the temperature gradient across the silicon melt in the crucible, which is caused by irradiating the melt with the plasma arc heater.
Vacuum Control: By changing the degree of vacuum in the vessel, evaporation conditions of the impurities in the silicon raw material can be controlled while avoiding superheating of the silicon melt, thus ensuring the safety of the metallurgical silicon purifying process.
Crucible Shifting: The crucible is moved, for example by rotating and/or shifting vertically and/or horizontally, relative to the heater by the manipulating mechanism provided underneath the vessel. Moving the crucible can move the solidus-liquidus interface of the silicon melt to achieve one-directional cooling purification, without the need for temperature segregation coefficient management of the concentration of remaining impurities in the silicon melt with respect to the solidus-liquidus line.
In an embodiment, one or more of the above techniques are performed at the same time in the same apparatus. In another embodiment, all of the above techniques are performed at the same time in the same apparatus. The embodiments of the present invention do not require a new manufacturing apparatus to be installed; rather, a conventional apparatus used for manufacturing single-crystal silicon can be adapted to practice the methods on a mass production scale. Because of this, both the fixed and variable costs of manufacturing can be reduced.
As mentioned above, the silicon purifying method of the embodiments of the present invention involves adjusting an existing and widely used apparatus. The adjustments are simple, minimizing additional costs, and manufacturing flexibility is ample, so the method can be adjusted to satisfy market demands as necessary. The methods are capable of substantially reducing the costs and time required to purify metallurgical silicon for use in manufacturing solar cells and other suitable devices.
In addition to cost-effective purification, the methods according to embodiments of the present invention do not produce the amount of poisonous or dangerous substances found in the conventional art, resulting in a safer workplace that is better able to meet increasing levels of environmental regulation.
In an embodiment, a method for purifying metallurgical grade silicon into solar-grade silicon includes one or more of the following steps performed at the same time. An independent gas provision step uses an independent supply tube for supplying at least one highly pressurized gas towards burning hydrogen (H2) supplied by the plasma arc heater to the center of the surface of a silicon melt in a crucible, so as to generate a purifying substance for the silicon melt, with the generated purifying substance going into the silicon melt as a result of the high-pressure ejection of the purifying gas to effectively provide the silicon melt with the purifying substance, which is needed for the removal of impurities in the silicon melt. An intermittent heating and gas provision step intermittently performs irradiation of the silicon melt in the crucible by the plasma arc heater, so that the temperature at the surface of the silicon melt in the crucible forms a reproducible temperature gradient, which in turn forms a temperature distribution across the silicon melt in the crucible, and in addition, by controlling the purifying gas, intermittently providing enough purifying gas to the silicon melt surface to form the purifying substance, so as to provide a stable process for purifying metallurgical silicon. A chemical-adding step adds and blends substances including the impurities and/or silicon into the silicon melt so that the resulting compounds formed have relative densities smaller than the metallurgical silicon. A silicon melt mixing steps ejects the purifying gases with high pressure to the surface of the silicon melt in the crucible, so that at the same time the purifying substance is provided to the silicon melt, the stream of the high-pressure purifying gas forms a dimple on the silicon melt surface, increasing the contact area for the purifying substance, and meanwhile, the area with high temperate is increased by irradiating the plasma via the dimple, accompanied by heat convection caused by different temperatures across the silicon melt in the crucible, circulation within the silicon melt in the crucible is encouraged. A vacuum controlling step changes the degree of vacuum in a vessel of the apparatus to provide evaporation conditions of the impurities in the silicon starting material and for preventing superheating in the silicon melt, thus ensuring the safety of the process for purifying metallurgical silicon. A crucible shifting step rotates and/or vertically and/or horizontally shifts the crucible relative to the location of the heater by a manipulating mechanism provided underneath the vessel, so as to move the solidus-liquidus interface of the silicon melt to achieve one-directional cooling purification, without the need for temperature segregation coefficient management of the concentration of remaining impurities in the silicon melt with respect to the solidus-liquidus line.
In an embodiment, the purifying gas is oxygen (O2). The high-pressure oxygen provided to the center of the silicon melt surface and the burning hydrogen supplied by the plasma arc heater generate water vapor (H2O) through a hydrogen burning reaction, and the generated water vapor goes into the silicon melt as a result of the high-pressure ejection of the oxygen gas to effectively provide the purifying substance, water, needed for the removal of impurities in the silicon melt. The temperature range or distributions is formed in the silicon melt from 1450° C. to 3527° C. under one atmospheric pressure (the standard pressure).
According to an embodiment, in the intermittent heating and gas provision step, the duty cycle of intermittent plasma irradiation is below 50%.
According to an embodiment, in the intermittent heating and gas provision step, a temperature difference of 50° C. or above is formed in the crucible. A pressure pump is further provided to adjust the pressure before the purifying substance evaporates from liquid to gas and causes the pressure to rise.
According to an embodiment, the plasma arc heater locally irradiates the silicon melt to generate a local high temperature, and hydrogen is locally provided to the silicon melt. A material that generates oxygen and hydrogen is added, the material being water.
According to an embodiment, a material that generates monosilanes, oxygen and hydrogen is added. The material is argon (Ar).
According to an embodiment, a high-pressure and damped argon gas is ejected by the plasma arc heater to form local temperature differences in the silicon melt, and the time for purifying is reduced by increasing the contact area with the silicon melt through the dimple and the circulation caused by the dimple.
According to an embodiment, in the chemical-adding step, the chemicals added eventually generate a chloride substance. The added chemicals include compounds of calcium, silicon and magnesium, which blend with the silicon starting material. The added chemicals include soluble chemicals, and their vitreous structures are network modifiers, including calcium chloride (CaCl2) and magnesium chloride (MgCl2), and network formers, including sodium metasilicate (Na2SiO3).
According to an embodiment, in the vacuum controlling step, the degree of vacuum is controlled by a vacuum machine and the degree of vacuum is kept in a range between 0.1 Torr and 10 Torr.
According to an embodiment, in the crucible shifting step, the bottom of the crucible is positioned next to the bottom of the heater to reduce its bottom temperature and align the center of the heater with the center of the crucible.
According to an embodiment, a method for purifying silicon bearing materials for photovoltaic applications includes providing metallurgical silicon into a crucible apparatus. The metallurgical silicon is subjected to at least a thermal process to cause the metallurgical silicon to change in state from a first state to a second state, the second stage being a molten state not exceeding 1500 Degrees Celsius. At least a first portion of impurities is caused to be removed from the metallurgical silicon in the molten state. The molten metallurgical silicon is cooled from a lower region to an upper region to cause the lower region to solidify while a second portion of impurities segregate and accumulate in a liquid state region. The liquid state region is solidified to form a resulting silicon structure having a purified region and an impurity region. The purified region is characterized by a purity of greater than 99.9999%.
In an embodiment, the thermal process uses a plasma gun or arc heater.
In an embodiment, the crucible apparatus remains in a stationary state.
In an embodiment, the thermal process has a source of about 3000 Degrees Celsius.
In an embodiment, the molten metallurgical silicon has a temperature profile characterized by a higher temperature region within a center region and a lower temperature region within an edge region of the crucible apparatus.
In an embodiment, the thermal process comprises a thermal pulse or pulses.
In a embodiment, the thermal process comprises a convection process of the molten state.
In an embodiment, the molten state is substantially free from any foreign objects for circulating the molten metallurgical silicon.
In an embodiment, the method further comprises subjecting an upper molten region of the metallurgical silicon with an inert blanket of gas; and subjecting a portion of the upper molten region to a hydrogen gas to cause a reaction and remove a boron impurity with the hydrogen gas to remove the oxygen impurity, wherein the metallurgical silicon has a purity of about 99%.
In an embodiment, the method further comprises subjecting a region of the molten metallurgical silicon to a hydrogen species to remove a boron impurity using a gas selected from at least one of B2O3, B2O3H2O, BH4, B2H6, BH3, H3BO3, HBO2, HBO3, H4B2O4, H3BO2, H3BO, H2B4O7, B2O2, B4O3 or B4O5.
In an embodiment, the hydrogen species is injected using one or more channel regions.
In an embodiment, the crucible is maintained in a vacuum to keep the molten metallurgical silicon free from external contaminants.
In an embodiment, the vacuum is selected to achieve a desired impurity removal characteristic from the molten metallurgical silicon.
According to an embodiment of the present invention, a method for purifying silicon for photovoltaic applications includes providing metallurgical silicon into a crucible apparatus; subjecting the metallurgical silicon to at least a thermal process to cause the metallurgical silicon to change in state from a first state to a second state; causing at least a portion of impurities from being removed from the metallurgical silicon in the molten state; and maintaining the metallurgical silicon in a vacuum to selectively adjust a temperature of the molten state of the metallurgical silicon.
In an embodiment, the method further comprises subjecting the crucible apparatus to a cooling process using one or more cooling tubes, wherein the metallurgical silicon has a purity of about 99%.
According to an embodiment of the present invention, a method for purifying silicon bearing materials for photovoltaic applications includes providing metallurgical silicon into a crucible apparatus; subjecting the metallurgical silicon to at least a thermal process to cause the metallurgical silicon to change in state from a first state to a second state, the second stage being a molten state not exceeding 1500 Degrees Celsius; causing at least a first portion of impurities from being removed from the metallurgical silicon in the molten state; subjecting an upper molten region of the metallurgical silicon with an inert blanket of gas to prevent external impurities from contacting the metallurgical silicon in the molten state; and subjecting a portion of the upper molten region to a hydrogen gas to cause a reaction to cause removal of a boron impurity with the hydrogen gas.
In an embodiment, boron impurity is removed using a gas selected from at least one of B2O3, B2O3H2O, BH4, B2H6, BH3, H3BO3, HBO2, HBO3, H4B2O4, H3BO2, H3BO, H2B4O7, B2O2, B4O3 or B4O5.
In an embodiment, the hydrogen species is injected using one or more channel regions.
According to an embodiment of the present invention, a method for purifying silicon bearing materials for photovoltaic applications includes providing metallurgical silicon having a purity of 99% into a crucible apparatus; and subjecting the metallurgical silicon to at least a thermal process to cause the metallurgical silicon to change in state from a first state to a second state, the second state of the metallurgical silicon including an inner portion having a temperature ranging from about 2500 to 3000 Degrees Celsius and an outer portion having an outer temperature not exceeding 1500 Degrees Celsius; and causing a convective current from a temperature differential between the inner portion and the outer portion of the metallurgical silicon.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a cross-sectional diagram depicting a simplified conventional apparatus for growing single silicon crystals.
FIG. 2 is a cross-sectional diagram depicting a simplified silicon purifying apparatus according to an embodiment of the present invention.
FIG. 3 is a cross-sectional diagram along line A-A of FIG. 2 .
FIG. 4 is a schematic diagram illustrating simplified gas flow according to an embodiment of the present invention.
FIG. 5 is a detailed diagram illustrating gas flow and control of the gas flow according to an embodiment of the present invention.
FIG. 6 is a graph depicting an instantaneous temperature distribution across the surface of a silicon melt when irradiated by plasma.
FIG. 7 is a schematic diagram illustrating mixing the silicon melt, according to an embodiment of the present invention.
DETAILED DESCRIPTION OF THE EMBODIMENTS
The present invention relates to methods for purifying metallurgical silicon. An embodiment of the prevent invention includes an independent gas provision step, an intermittent heating and gas provision step, a chemical-adding step, a silicon melt mixing step, a vacuum controlling step, and a crucible shifting step. According to implementation a plurality or all of these steps may be performed at the same time in the same apparatus to generate solar-grade silicon in mass production without using any poisonous chemicals. Various aspects of the present invention are described using the embodiments described herein. A person skilled in the art would understand that the examples and embodiments described herein are for illustrative purposes only and that various modifications or changes thereof would be possible without departing from the spirit and purview of this invention.
FIG. 1 shows a cross-sectional diagram depicting a simplified conventional apparatus used for growing single silicon crystals. A vessel 1 contains a crucible 2 supported by a crucible support 3 and heated by a heater 4 .
Single-crystal growing techniques, which purify a solid part while growing crystals in the same crystalline orientation as the seed crystal based on the difference in the segregation coefficient between solidus and liquidus, are widely used for manufacturing of semiconductor apparatus and are well known in the art.
The present inventors have proposed methods for purifying low-purity metallurgical silicon, such as metallurgical silicon used in the steel or aluminum industries, to produce solar-grade silicon by re-designing the traditional apparatus used for single-crystal silicon growth.
Embodiments of the present invention provide a new method for purifying metallurgical silicon that enhances the efficiency and effect of the various functions such as purification, stabilization, ignition, and circulation. In an embodiment, the metallurgical silicon used has a purity of about 99%. In another embodiment, the silicon used may have a different purity level.
In other words, the present invention devises a new independent gas supply for supplying gases for stable and efficient plasma. The plasma arc heater is arranged in such a way that it does not interfere with other means for improving purification and maintains the stable use condition for other purification techniques used according to the present invention.
An embodiment of the present invention provides, an independent gas supply for different purification gases, e.g., H2 and O2, so that an increased amount of H2, H2O and O2 reach the silicon melt in the crucible. The purification gases including O and H are directly blown onto the surface of the silicon melt. These gases easily react with impurities in the silicon melt, such as boron, and produce boron compounds which are easily evaporated. Examples of boron compounds that are difficult to remove from silicon melt by conventional methods but are readily removed according to an embodiment of the present invention include the following: B2O3, B2O3H2O, BH4, B2H6, BH3, H3BO3, HBO2, HBO3, H4B2O4, H3BO2, H3BO, H2B4O7, B2O2, B4O3, B4O5, etc. In addition, the apparatus and methods disclosed herein may apply to the purification of other elements.
By providing an independent gas supply inlet purification gases H2 and O2, a greater amount of these gases are allowed to reach the surface of the silicon melt for reaction with impurities in the silicon melt. If H2 and O2 provided through the same inlet, much of these purification gases would react with each other before they reach the surface of the silicon melt.
Another feature of the present embodiment resides in the intermittent provision of plasma and purifying gases. The differences between intermittent and continuous provision are now compared.
When providing plasma continuously to the surface of the silicon melt according to the conventional art, the temperature of the silicon in the crucible 2 increases over time, and it is therefore necessary to lower the power of the plasma to avoid melting the crucible. Because of this, the temperature of the silicon varies with time, so that the temperature distribution across the silicon is not uniform. As a result, the purification conditions also vary with time.
In the present embodiment, the power to the plasma is supplied intermittently. As a result, the temperature of the silicon of the present embodiment also increases with time according to a pattern after certain time intervals and repetitive intermittences, i.e., it varies in a reproducible manner. The pattern may be a constant pattern. Thus, the temperature gradient may have reproducible changes, so stable purification can be achieved in mass production.
When providing purifying gases continuously, as described above, the temperature inside the plasma arc heater will increase due to gas combustion. Furthermore, if H2O is continuously provided for purification, according to the Avogadro constant, the pressure will increase and pose a danger to the system. Therefore, an adequate amount of H2O for efficient purification of the silicon cannot be supplied through the continuous process. Consequently, a compromise must be made between increases in temperature and pressure, and the amount of H2O supplied.
The present embodiment adopts the intermittent approach of supply by providing purification gases periodically, where purification gases are supplied during one period and then not supplied in another period, and so on. Using the intermittent method, a desired amount of H2O is provided for purification. In an embodiment, the amount of H2O supplied is fined tuned during the purification process as needed. In addition, a pressure pump is provided to reduce pressure before H2O vaporizes from the liquid phase and increases the pressure in the chamber. Thus, the present embodiment is able to perform stable purification under safe and reproducible conditions.
A method for purifying metallurgical silicon according to an embodiment of the present invention is provided below.
Manufacturing Steps in Present Embodiment:
Sequence
Description
Step One
Generate partial high temperature by plasma irradiation
Efficiently remove impurities via a vacuum
Directly supply water and gases towards the surface of the
silicon melt
Efficiently and uniformly supply water and gases into the
silicon melt in the crucible
Allow the silicon melt to efficiently circulate inside crucible
Intermittently provide plasma and purification gases to
achieve a safe process, maximize purification, and reduce
power consumption
Step Two
Remove impurities with one directional cooling by crucible
shifting
In the method disclosed above, the purification is performed by performing a plurality of purification techniques in the same apparatus at the same time, so as to achieve up to four different purification reactions: physical, chemical, mechanical and metallurgical. In another embodiment, the purification method may perform only one purification technique or all the purification techniques disclosed above.
An embodiment of the present invention is now described in detail in order to enable one with ordinary skills in the art to fully understand and reproduce and practice the present invention. Although the embodiment is described using the conventional apparatus shown in FIG. 1 , one of skill in the art will appreciate that the present invention may be implemented using a different apparatus.
First, when chemically purifying silicon raw material containing impurities, the silicon raw material is heated to 1500° C. by the heater 4 . Meanwhile, Argon (Ar) gas is provided at 800 L/hour to the vessel 1 to prevent oxidation of the silicon melt.
Since the silicon raw material contains a variety of metal impurities having different inherent evaporation temperatures, in order to remove them, the crucible 2 is heated to temperatures corresponding to the different evaporation temperatures. A temperature gradient is generated in the crucible 2 . The resulting temperature distributions in the silicon melt in the crucible enables the impurities having different evaporation temperatures to be evaporated.
The actual evaporation, or boiling point, temperatures of some typical metal elements under one atmospheric pressure that might be observed in the silicon raw material are listed below:
Al: 2327° C.
Sb: 1617° C.
B: 3527° C.
Ca: 1482° C.
Cu: 2595° C.
Mn: 2097° C.
Fe: 2727° C.
Ni: 2837° C.
Ti: 1457° C.
Thus, the crucible 2 would need to tolerate temperatures between 1457° C. and 3527° C. for evaporation of the above metal impurities. Typically, the temperature of the silicon in the crucible 2 ranges from 1450° C. to 1550° C. In an embodiment, however, the temperature gradient of the silicon melt in the crucible is provided to have a temperature distribution from 1457° C. to 3527° C. under one atmospheric pressure, thereby enabling evaporation of boron at 3527° C.
Second, the pressure within the vessel is kept at 10 Torr and the vessel is supplied with H 2 O, so as to allow the impurities in the silicon raw material to produce compounds that are more easily evaporated. Meanwhile, a temperature gradient is formed on the surface of the silicon melt in the way described below in order to allow all resulting compounds to reach their inherent evaporating temperatures. Because the pressure in the vessel is lower than atmospheric pressure, the actual evaporation temperatures of the impurities will be lower than the reference values listed above.
In order to irradiate the plasma to achieve the desired temperature gradient, the power of the plasma is adjusted to 20 KW, and the diameter of the irradiation area is adjusted to below 10 mm. Intermittent irradiation is used to limit any increase in the overall temperature of the silicon melt as a result of the plasma irradiation. Based on experimentation conducted by the present inventors, a temperature gradient such as that shown in FIG. 6 can be observed when the duty cycle is below 50%.
As noted above, in order to remove metal impurities in the silicon, it is necessary to reach various evaporating temperatures for the impurities using the temperature of the crucible 2 as a reference point. According to the temperatures listed above, the greatest temperature difference formed in the melt is 2077° C., resulting from a temperature distribution of 1450° C. to 3527° C., and the smallest temperature difference is 7° C., resulting from a temperature distribution of 1450° C. to 1457° C. However, in light of actual operations and tests and considering safety management under high temperatures, it is preferred that the temperature difference of the crucible 2 be kept within 1500° C.+/−50° C.
In theory, it is quite difficult to perform removal of boron impurities using the segregation method. However, when H 2 O is added to silicon having the temperature gradient described above, the boron-bearing content of the raw material is lowered to an average of 0.3 ppm from 30 ppm, thereby achieving purification. In addition to reaction with H 2 O, the compounds in H 2 O, such as O and H, chemically react with the boron impurities in the silicon raw material and form chemicals that are easily evaporated, such as B 2 O 3 , B 2 O 3 H 2 O, BH 4 , B 2 H 6 , BH 3 , H 3 BO 3 , HBO 2 , HBO 3 , H 4 B 2 O 4 , H 3 BO 2 , H 3 BO, H 2 B 4 O 7 , B 2 O 2 , B 4 O 3 and B 4 O 5 .
Moreover, in regard to removing impurities in the silicon raw material, calcium (Ca), silicon (Si) and magnesium (Mg) chemical compounds are blended into the silicon raw material in order to react with the impurities and form slag.
Because silicon raw material has different shapes and sizes, it is very difficult for additives to completely and uniformly come into contact with the silicon raw material. In order to solve this problem, soluble calcium chloride (CaCl 2 ), magnesium chloride (MgCl 2 ), and sodium silicate (Na 2 SiO 3 ), are blended with the raw material. The result is that the levels of impurities are almost the same across the whole resulting purified silicon. This indicates a uniform purification using soluble additives.
In the present embodiment, the concentrations of Ca and Mg, which are used as network modifiers, and Si, which is used as a network former, in vitrification, are all set to 100 ppm with respect to the silicon raw material. However, in other embodiments, the appropriate concentrations may vary with the impurities incorporated in the silicon raw material.
In addition, among the various chemical compounds formed from added Ca and Mg, such as oxide, chloride and carbonic acid, chloride gives high purity even when the process begins with a silicon raw material having impurity levels of 97-98%. The main reason for this is that the chloride impurities in the silicon raw material have high vapor pressure, and thus they can be easily removed.
In order to efficiently remove boron-based impurities according to the prior art, it is necessary to add H 2 O to the silicon melt. However, the surface temperature of the silicon melt is as high as 1450° C.˜1550° C., so H 2 O will evaporate before reaching the surface. As a result, the boron-based impurities are not removed efficiently. A solution proposed according to an embodiment of the present invention is explained below.
H 2 gas is locally provided towards the silicon melt. In an embodiment, the distance between the silicon melt and a first supply tube for the H 2 gas is about 5 mm to 15 mm. If the distance is shorter than 5 mm, the temperature of the tube may rise due to the silicon melt and cause the tube to expand due to the thermal expansion and contact the melt. If the distance is greater than 15 mm, H 2 O may not be efficiently supplied to the surface of the silicon melt according to the present embodiment. In another embodiment, the distance between the silicon melt and the supply tube is no more than 10 mm. In yet another embodiment, the distance between the silicon melt and the supply tube is no more than 20 mm. The distance between the silicon melt and the supply tube may vary according to implementation.
Next, high pressure O 2 is supplied via a second supply tube towards the center of the H 2 gas supplied to the silicon melt. The H 2 gas supplied by the first supply tube reacts with the O 2 gas supplied by the second supply tube due to the high temperature of the silicon melt, thereby causing H 2 gas to burn. In this case, oxidizing engineering used in semiconductor apparatus manufacturing is applicable to the process, that is, water vapor is generated by burning hydrogen, which is well-known in the art. The water vapor goes deep into the silicon melt due to the ejection force of the O 2 , thereby efficiently supplying water vapor to the silicon melt. The water vapor supplied into the silicon melt reacts with boron-bearing impurities therein, thereby removing boron from the silicon melt.
In an embodiment, O 2 is supplied at a pressure of 2 kg/cm 2 . In another embodiment, flow rate of H 2 is 700 L/hour and of O 2 is 500 L/hour. In general, higher pressures result in better purification.
In addition, when H 2 O is supplied to the silicon melt, the stream of the high-pressure O 2 gas causes a dimple to be formed on the surface of the silicon melt. This increases the inversion radius of the silicon melt circulating in the crucible 2 , which facilitates mixing. The increased mixing allows the impurities to be distributed more evenly and the silicon melt to be purified in a shorter time.
The following surprising results have been found by the inventors: (1) Boron-bearing impurities can be removed efficiently by supplying H 2 O effectively to the surface of the silicon melt; (2) the contact area for H 2 O penetration is increased by forming a dimple on the silicon melt by supplying a gas at high pressure towards the silicon melt; and (3) mixing is facilitated by the dimple formed on the silicon melt by the high-pressure gas. The high-pressure gas is oxygen gas in the present embodiment.
In other embodiments, in order to efficiently form the aforementioned dimple, argon (Ar) gas may be provided from another tube (e.g., a third supply tube) separate from the tube providing O 2 . The argon supplied by these embodiments may be damped, obviating, reducing, or supplementing the water supplied through O2 and H 2 gases. In an embodiment, the Ar flow rate is 100 L/min, the damping percentage is 100%, and the damping method is diffusing fine Ar gas across water.
The degree of vacuum also plays a significant role in embodiments of the present invention. Each impurity incorporated in the silicon raw material has an inherent boiling point and vapor pressure that depends according to the pressure level in the vessel. In an embodiment, the temperature of silicon melt without influence of plasma is 1550° C., and the chamber pressure is 0.1 Torr. In this embodiment, it is found that the silicon melt reacts vigorously at the interface with the quartz crucible 2 , and superheating occurs at the surface of the silicon melt. However, if the chamber pressure is raised to 10 Torr with the other conditions remaining the same, the degree of superheating will be reduced. Therefore, the present embodiment, the chamber pressure of 0.1 Torr or more is preferred.
The inventors have found that the boiling temperatures of the impurities in the silicon raw material vary considerably depending on the vacuum level (or chamber pressure). For example, the difference in boiling temperatures between vacuum levels of 0.1 Torr and 10 Torr is about 500° C. for B, about 400° C. for Fe, about 350° C. for Al, and about 320° C. for Ni. In other words, the purification temperature difference of the metal impurities caused by a pressure difference of 100 times is around 300° C.
Burning hydrogen from H 2 and O 2 to form H 2 O as described above is especially effective in removing boron-bearing impurities from the silicon melt. The addition of damped Ar not only contributes to removing boron-bearing impurities, but also facilitates circulation of the silicon melt within the crucible 2 , which allows for more uniform purification. That is, by injecting damped Ar to form local temperature differences in the silicon melt, a dimple is formed, and as a result, the contact area with the silicon melt can be increased, resulting in more effective purification. Due to this multiplication effect, mixing can be done in a shorter period, reducing the time required for purification. This result is confirmed in the following experiment: flow rate of damped Ar: 100 L/min. Fine Ar bubbles are formed in water, and the experiment is controlled so that the Ar bubbles remain at a depth of 50 cm in the water when Ar in the bubbles has a relative dampness of 100%. This achieves the effect of reducing the purification time by 5%.
When the temperature of the silicon melt is kept at 1450° C., the temperature in the vessel will rise as a result of providing damped Ar via the plasma arc heater. This suggests that, in the plasma, damped portions of the argon gas will decompose into H 2 and O 2 , and a portion of H 2 will combust. Also, under the above conditions, analysis of the exhaust gases suggests that the damped portions and Si react to form monosilanes (SiH 4 ). In other words, the result of adding damped Ar will give rise to O 2 , H 2 and SiH 4 .
The following methods for purifying metallurgical silicon are described, in reference to the drawings, using embodiments that are modifications of a conventional apparatus for growing single silicon crystals.
The apparatus shown in FIGS. 2 to 7 includes a vessel 10 , a vacuum exhaust tube 11 , a crucible 20 , safety means 21 and 31 for preventing penetration by plasma, a crucible support 30 , a heater 40 , a plasma arc heater 50 , a gas supply tube 60 , silicon melt 100 , and a manipulating mechanism 80 for rotating and shifting the crucible support 30 up and down.
Before silicon raw material containing impurities is chemically purified, it is heated by the heater 40 to form the silicon melt 100 . Then, one or more of the various methods for purification according to the present invention are applied, which include the following:
1. Independent Gas Provision: An independent supply tube 60 supplies highly pressurized O 2 gas towards H 2 supplied by the plasma arc heater to the center of the surface of the silicon melt 100 in the crucible 20 so as to generate water vapor (H 2 O). The generated water vapor goes into the silicon melt, as a result of the high-pressure ejection of O 2 in order to effectively provide the silicon melt 100 with the water vapor that is used to remove impurities. 2. Intermittent Heating and Gas Provision: Irradiation of the silicon melt 100 in the crucible 20 is intermittently performed by the plasma arc heater 50 , so that a reproducible temperature gradient such as that shown in FIG. 6 is formed at the surface 100 a of the silicon melt in the crucible 20 . This forms a temperature distribution across the silicon melt 100 in the crucible 20 , preventing the crucible from melting while providing adequate, stable and uniform conditions for metallurgical silicon purification. FIG. 6 shows a graph depicting an instantaneous temperature distribution across the silicon melt surface 100 a in the crucible 20 when irradiated by plasma. In addition, purifying gases for forming the water vapor are provided intermittently to avoid a rise in pressure caused by continuous provision of the water vapor. Moreover, a pressure pump is used to adjust pressure via the vacuum exhaust tube 11 before H 2 O vaporizes from liquid to gas and causes the pressure to rise, thus providing a safe and stable process environment for purifying metallurgical silicon. 3. Addition of Chemicals: Chemicals such as Ca, Si and Mg are added to the raw silicon material to react with the impurities therein, and the resulting compounds formed by reaction between the chemicals and the silicon have lower densities relative to metallurgical silicon, which allows the impurities to be easily removed. A method according to an embodiment includes adding soluble chemicals whose vitreous structures may be network modifiers including, for example, calcium chloride (CaCl 2 ) and magnesium chloride (MgCl 2 ), and soluble chemicals whose vitreous structures may be network formers including, for example, sodium metasilicate (Na 2 SiO 3 ). These soluble chemicals contact or blend with the metallurgical silicon to form slag with the impurities in the silicon raw material, which floats up to the silicon melt surface 100 a and may be easily evaporated. 4. Silicon Melt Mixing: By ejecting purifying gases with high pressure via the supply tube 60 towards the surface 100 a of the silicon melt in the crucible 20 , the stream of the high-pressure purifying gases forms a dimple 90 on the silicon melt surface 100 a as shown in FIG. 7 , thereby increasing the contact area for H 2 O when H 2 O is provided to the silicon melt. Meanwhile, due to the increase in the high-temperature area from irradiating with plasma via the dimple 90 by the plasma arc heater 50 , accompanied by heat convection due to different temperatures across the silicon melt 100 in the crucible 20 , circulation within the silicon melt 100 in the crucible 20 is encouraged. 5. Vacuum Control: By changing the degree of vacuum in the vessel 10 , evaporation conditions of the impurities in the silicon raw material can be controlled and superheating of the silicon melt 100 can be avoided, thus ensuring the safety of the metallurgical silicon purifying process. 6. Crucible Shifting: The crucible 20 is moved, for example by rotating, or shifting it vertically or horizontally shifted relative to the heater 40 by the manipulating mechanism 80 provided underneath the vessel 10 , so that the solidus-liquidus interface of the silicon melt 100 can be moved to achieve one-directional cooling purification, without the need for temperature segregation coefficient management of the concentration of remaining impurities in the silicon melt 100 with respect to the solidus-liquidus line. Since the vertical shifting and rotating of the crucible 20 are related to the one-directional cooling purification using the segregation coefficient, when the silicon melt 100 is slowly cooled down and solidified, impurities at the solidus side are purified. The embodiments of the present invention eliminate the need for temperature management to cool the silicon melt 100 by performing one-directional purification through changing the position of the crucible 20 relative to the heater 40 , and in turn shifting the solidus-liquidus interface. In this case, the shifting speed of the solidus-liquidus interface is dependent on the amount of silicon melt 100 in the crucible 20 . In an embodiment, average shifting speeds of less than 1.0 mm/min are used to obtain desired results.
It can be understood from the purifying methods according to the embodiments of the present invention that the effective circulation of silicon melt 100 has great influence on the uniform removal of impurities therein. If there is too little circulation, the silicon quality varies. Heat convection in the silicon melt 100 in the crucible 20 is caused by temperature differences across the vertical profile. However, the following methods can be performed in parallel to obtain better circulation:
1. Moving the bottom of the crucible 20 to the bottom of the heater 40 to reduce its bottom temperature, wherein the center of the heater 40 is aligned with the center of the crucible 20 ; 2. Forming a dimple 90 on the surface of the silicon melt 100 to increase the inversion radius of the circulation, thereby enhancing uniform purification of the impurities; 3. Increasing the high-temperature area by irradiating with plasma through the dimple 90 to increase the inversion radius of the circulation, thereby enhancing uniform purification of the impurities; and 4. Irradiating with plasma intermittently to prevent overheating of the overall silicon melt 100 and to maintain a suitable temperature gradient.
FIG. 4 is a schematic diagram depicting gas flow when heated according to an embodiment of the present invention. This embodiment comprises a guide 70 with fins for controlling gas flow, in particular for allowing the purifying gases supplied by the gas supply tube 60 to contact the silicon melt 100 . Reference letter “a” indicates heat flow from the heater 40 , “p” indicates plasma, and “g” indicates gas flow.
The steps and conditions performed by the present embodiment shown in FIG. 4 are as follows:
The temperature of the silicon melt 100 is about 1550° C., the power supplied to the plasma is 20 KW, and the maximum temperature is about 3000° C. The temperature distribution of the silicon melt 100 in the crucible 20 is from about 1550° C. to 3000° C. The purifying gases supplied by the supply tube 60 in FIG. 4 are high in temperature and will eventually form oxygen, hydrogen and/or monosilanes (SiH 4 ) in liquid or solid form and/or a mixture thereof. In order to prevent oxidation of the silicon melt 100 , Ar is provided to the silicon melt surface 100 a.
The temperature distribution has a significant effect on the purifying steps. There are various impurities that need to be removed. The chemical reactions, evaporation, transformation, and other chemical activities of these impurities depend on temperatures. The temperatures distribution within the silicon melt allows parts of the silicon melt to be increased to a high temperature necessary to cause certain materials to evaporate, e.g., evaporate boron at about 3527° C.
In conventional methods, although water is provided via the supply tube 60 to the vessel 10 , it is evaporated before it reaches the silicon melt 100 due to the high temperature of silicon melt, making it difficult to perform purification effectively.
In order to solve this problem, the gas flow is controlled as shown in FIG. 5 , wherein the arrows indicate the direction of gas flow. A high-power vacuum machine is used to create high-speed gas flow, and the gas flow is directed by the guide 70 to go against the rising gas flow from the silicon melt 100 caused by heating the silicon melt surface 100 a , so that the damped gases can contact the silicon melt surface 100 a effectively. Moreover, in order to increase efficiency, the distance (h 1 ) from one end of the gas flow guide 70 to the silicon melt surface 100 a , the distance (h 2 ) from the gas flow controlling fin to the silicon melt 100 , and the distance (S) from the end of the guide 70 to the inner circumference of the crucible are very important. The distance between the guide 70 and the silicon melt surface 100 a can be adjusted by controlling the crucible using the manipulating mechanism 80 , thereby obtaining good recirculation. In various embodiments, 100 mm, 40 mm and 30 mm for h 1 , h 2 and S, respectively, obtain good results, and rate at which exhaust is let out by the vacuum machine is 15 m 3 /min.
Although the methods above perform purification on the silicon melt surface 100 a efficiently, the purifying gases/elements cannot be provided inside the silicon melt 100 . In other words, even if the silicon melt surface 100 a is purified, the distribution of the impurities in the silicon melt 100 inside the crucible 20 is still not even, and so mixing of the silicon melt 100 is necessary.
As shown in FIGS. 6 and 7 , the uneven distribution of the impurities in the silicon melt 100 may be solved by controlling the heating temperature gradient and the high-pressure gas stream that facilitates mixing. FIG. 7 illustrates mixing of the silicon melt 100 in the present embodiment. As shown in FIG. 7 , the silicon melt surface 100 a in the crucible 20 has a higher temperature than silicon at the bottom due to plasma irradiation, and a dimple 90 is formed on the silicon melt surface 100 a by the high-pressure stream from the supply tube 60 or the plasma arc heater 50 , which allows the contact area between the purifying gases and the silicon melt 100 to increase. When accompanied by heat convection in the crucible caused by the temperature distribution across the silicon melt 100 in the crucible, circulation can be sped up and uniform purification can be effectively obtained.
In addition, such actions can be repeated to reduce the rising temperature of the silicon melt 100 due to plasma irradiation and maintain the effect of adding water or damped gases. A plurality of irradiation sources can also be used.
As described above, the present invention relates to methods for purifying metallurgical grade silicon. The purified silicon (e.g., purified polysilicon) may be used in manufacturing solar cells and other suitable devices. In an embodiment, a method provides low-cost solar-grade silicon from low-purity metallurgical grade silicon by modifying the existing single-crystal silicon drawing apparatus used by the semiconductor industry.
A person skilled in the art would understand that the examples and embodiments described herein are for illustrative purposes only and that various modifications or changes thereof would be possible without departing from the spirit and purview of this invention. The scope of the present invention should be construed based on the appended claims. | A method for purifying silicon bearing materials for photovoltaic applications includes providing metallurgical silicon into a crucible apparatus. The metallurgical silicon is subjected to at least a thermal process to cause the metallurgical silicon to change in state from a first state to a second state, the second stage being a molten state not exceeding 1500 Degrees Celsius. At least a first portion of impurities is caused to be removed from the metallurgical silicon in the molten state. The molten metallurgical silicon is cooled from a lower region to an upper region to cause the lower region to solidify while a second portion of impurities segregate and accumulate in a liquid state region. The liquid state region is solidified to form a resulting silicon structure having a purified region and an impurity region. The purified region is characterized by a purity of greater than 99.9999%. | 8 |
FIELD OF THE DISCLOSURE
[0001] The disclosure relates generally to Aflatoxin templates and molecularly imprinted polymers (MIPs). In particular, the disclosure relates to reusable, ecologically friendly MIPs, methods of producing the same, and methods of utilizing the same (e.g., to sequester and/or adsorb aflatoxins). Compositions and methods of the disclosure find use in a variety of applications including dietary, therapeutic, prophylactic, food and beverage processing and manufacture, as well as research and quality control applications.
BACKGROUND
[0002] Mycotoxins are secondary metabolites secreted by a variety of fungi, often produced in cereal grains as well as forages before, during and after harvest. Forages and cereals naturally come into contact with fungal spores. The fungal contamination of plants and the bio-synthesis of toxins depend on the state of health of the plant before harvest, meteorological conditions, harvesting techniques, delays and hydrothermal conditions before stabilization for conservation and feed processing. Depending on the fungus, fungal growth is controlled by a number of physico-chemical parameters including the amount of free water (a w ), temperature, presence of oxygen, nature of the substrate, and pH conditions. Mycotoxins proliferate pre-harvest as well as post-harvest in storage.
[0003] Some fungi produce toxins only at specific levels of moisture, water availability, temperature or oxygen. The effects of mycotoxins vary greatly in their severity. Some mycotoxins are lethal, some cause identifiable diseases or health problems, some weaken the immune system without producing symptoms specific to that mycotoxin, some act as allergens or irritants, and some have no known effect on animals or humans. According to recent United Nation's Food and Agriculture Organization (FAO) reports, approximately 25% of the world's grain supply is contaminated with mycotoxins. Mycotoxin contamination has a negative economic impact on food and feed producers, particularly grain and animal producers.
[0004] Mycotoxins can appear in the food chain as a result of fungal infection of plant products (e.g., forage, grain, plant protein, processed grain by-products, roughage and molasses products), and can either be eaten directly by humans, or introduced by contaminated grains, livestock or other animal feedstuff(s). Mycotoxins greatly resist decomposition during digestion so they remain in the food chain in edible products (e.g., meat, fish, eggs and dairy products) or under the form of metabolites of the parent toxin ingested. Temperature treatments such as cooking and freezing are not adequate methods of decreasing the prevalence of mycotoxins. Thus, there exists a need for compositions and/or methods for reducing the detrimental effects and/or eliminating mycotoxin occurrence in feed and/or food chains.
[0005] Aflatoxins are members of the mycotoxin family. These toxins are produced by moulds of the Aspergillus sp. such as Aspergillus flavus or A. Parasiticus that contaminate a variety of feed and food materials and that can ultimately transfer in their native form or has metabolites in animal by-products such as milk, eggs or potentially meat. Aflatoxins represent a significant health risk due to their high toxicity and carcinogenicity and regulatory levels are strictly enforcing their acceptable concentration in animal feeds and human food.
SUMMARY
[0006] There is a need for isolation of aflatoxins and metabolites from materials both for diagnostic and mitigation purposes. Molecularly imprinted polymers (MIPs) as described herein are materials exhibiting molecular recognition of an aflatoxin. MIPs are synthesized in the presence of an aflatoxin template (e.g. a mimic of aflatoxin), which is used to make an imprint and then is removed from the polymer after completion of the polymerization process, leaving a cavity in the polymer of the same stereochemistry, functionality, and morphology of the template. When the MIP encounters the aflatoxin, the aflatoxin is bound in the cavity.
[0007] The present disclosure relates generally to aflatoxin templates and molecularly imprinted polymers (MIPs). In particular, the disclosure relates to reusable, ecologically friendly MIPs, methods of producing the same, methods of utilizing the same (e.g., to sequester and/or adsorb aflatoxins), and methods for applying the use in different ways (e.g., to detect presence of aflatoxins for traceability purposes and to remove aflatoxins from a contaminated source). Compositions and methods of the disclosure find use in a variety of applications including dietary, therapeutic, prophylactic, food and beverage processing and manufacture, liquid filtering as well as research and quality control applications.
[0008] In embodiments, aflatoxin templates, monomers, crosslinkers, and/or MIPs have favorable safety and/or environmental properties such as reduced or no toxicity, and high water sorption, and retention of aflatoxins. In preferred embodiments, MIPs can be reusable and economically realizable/producible.
[0009] In one aspect of the disclosure, aflatoxin templates are provided. In a particular embodiment, an aflatoxin template has a Formula (I):
[0000]
[0000] wherein R 1 is selected from H, C 1-6 alkyl, substituted C 1-6 alkyl, and a halo substituted C 1-6 alkyl; R 2 is selected from halo, C 1-6 alkyl, substituted C 1-6 alkyl, a halo substituted C 1-6 alkyl, CH 2 C(O)OR′, and CH(C(O)OR′) 2 ; wherein R′ is selected from H, C 1-6 alkyl, and substituted C 1-6 alkyl; and R 3 is selected from H, C 1-6 alkoxy, and substituted C 1-6 alkyl. In embodiments, R′ further comprises substituents selected from a group consisting of halo, hydroxy and alkoxy. In a specific embodiment, an aflatoxin template is an isolated compound that has a Formula of:
[0000]
[0000] Additional embodiments include aflatoxin templates that have a formula selected from the group consisting of:
[0000]
[0000] and combinations thereof.
[0010] Another aspect of the disclosure includes a method of synthesis of an aflatoxin template of Formula (I) comprising: reacting 3,5-dimethoxy phenol with ethyl 4-chloroacetoacetate in acid to form 4-(2-chloroethyl)-5,7-dimethoxy coumarin.
[0011] In other embodiments, a method of synthesis of an aflatoxin template comprises suspending a monoacid according to the Formula of:
[0000]
[0000] in polyphosphoric acid and heating to at least 50° C.; cooling the reaction mixture below 50° C. and adding an aqueous solution to obtain an aflatoxin template according to the Formula of:
[0000]
[0012] In other embodiments, a monoacid is provided by suspending a diacid according to a Formula of:
[0000]
[0000] in a solvent and heating to at least 100 to 140° C.
[0013] In another embodiment, a method of synthesis of an aflatoxin template comprises: deprotecting a diethyl intermediate 2-((5,7-dimethoxy-2-oxo-2H-chromen-4-yl)methyl)malonate to form a diacid analog; and precipitating the diacid analog to isolate the aflatoxin template according to the Formula of:
[0000]
[0014] In other embodiments, a diethyl 2-((5,7-dimethoxy-2-oxo-2H-chromen-4-yl)methyl)malonate is prepared by a method comprising: combining 4-(2-chloroethyl)-5,7-dimethoxy coumarin with diethyl malonate, potassium iodide, and a crown ether in a polar solvent to form a mixture; and adding potassium butoxide to the mixture to form diethyl 2-((5,7-dimethoxy-2-oxo-2H-chromen-4-yl)methyl)malonate.
[0015] In other embodiments, a method of synthesis of an aflatoxin template of Formula (I) comprises: deprotecting diethyl 2-((5,7-dimethoxy-2-oxo-2H-chromen-4-yl)methyl)malonate to form a diacid analog, and precipitating the diacid analog according to the Formula:
[0000]
[0000] Suspending the diacid analog in a solvent, heating to at least 100 to 140° C., and precipitating the monoacid according to the Formula:
[0000]
[0000] Suspending the monoacid in an acid and heating to at least 50° C., cooling the reaction mixture to below 50° C., and adding an aqueous solution to obtain a compound according to the Formula:
[0000]
[0016] Another aspect of the disclosure provides a molecularly imprinted polymer intermediate comprising a complex of a crosslinked polymer made from a monomer and an aflatoxin template having a Formula (I):
[0000]
[0000] wherein R 1 is selected from H, C 1-6 alkyl, substituted C 1-6 alkyl, and a halo substituted C 1-6 alkyl; R 2 is selected from halo, C 1-6 alkyl, substituted C 1-6 alkyl, a halo substituted C 1-6 alkyl, CH 2 C(O)OR′, and CH(C(O)OR′) 2 ; wherein R′ is selected from H, C 1-6 alkyl, and substituted C 1-6 alkyl; and R 3 is selected from H, C 1-6 alkoxy, and substituted C 1-6 alkyl, or wherein R 1 together with R 2 form a C 4-7 cycloalkyl ring, a halo substituted C 4-7 cycloalkyl ring, an oxo substituted C 4-7 cycloalkyl ring, C 4-7 cycloalkoxy ring a hydroxy substituted C 4-7 cycloalkyl ring and a carboxylic group substituted C 4-7 cycloalkyl; and R 3 is selected from H, C 1-6 alkoxy, and substituted C 1-6 alkyl. In particular embodiments, the molecularly imprinted polymer intermediate has an aflatoxin template to monomer ratio from about 100:1 to 1:100. In other embodiments, the molecularly imprinted polymer intermediate has a monomer to crosslinker ratio from about 1:4.1 to 1:10. In yet other embodiments, the molecularly imprinted polymer intermediate includes an aflatoxin template of Formula (I) selected from the group consisting of 4-(2-chloroethyl)-5,7-dimethoxy coumarin, 5,7-dimethoxycyclo pentenon[2,3-c]coumarin, and combinations thereof.
[0017] Another aspect of the disclosure includes a molecularly imprinted polymer comprising a crosslinked polymer made from a monomer, wherein the polymer has a plurality of cavities, wherein at least one of the cavities was made using the aflatoxin template having a Formula (I):
[0000]
[0000] wherein R 1 is selected from H, C 1-6 alkyl, substituted C 1-6 alkyl, and a halo substituted C 1-6 alkyl; R 2 is selected from halo, C 1-6 alkyl, substituted C 1-6 alkyl, a halo substituted C 1-6 alkyl, CH 2 C(O)OR′, and CH(C(O)OR′) 2 ; wherein R′ is selected from H, C 1-6 alkyl, and substituted C 1-6 alkyl; and R 3 is selected from H, C 1-6 alkoxy, and substituted C 1-6 alkyl, or wherein R 1 together with R 2 form a C 4-7 cycloalkyl ring, a halo substituted C 4-7 cycloalkyl ring, an oxo substituted C 4-7 cycloalkyl ring, C 4-7 cycloalkoxy ring a hydroxy substituted C 4-7 cycloalkyl ring and a carboxylic group substituted C 4-7 cycloalkyl; and R 3 is selected from H, C 1-6 alkoxy, and substituted C 1-6 alkyl. In particular embodiments, the molecularly imprinted polymer includes an aflatoxin template that is 4-(2-chloroethyl)-5,7-dimethoxy coumarin. In embodiments, the molecularly imprinted polymer includes an aflatoxin template that is 5,7-dimethoxycyclo pentenon[2,3-c]coumarin. In embodiments, a molecularly imprinted polymer has a monomer that is selected from the group consisting of methacrylic acid, 2-vinylpyridine, 2-hydroxyethylmethacrylate and combinations thereof. In embodiments, a molecularly imprinted polymer has a crosslinker that is ethylene glycol dimethacrylate. In yet other embodiments, the molecularly imprinted polymer has aflatoxin template to monomer ratio that is from about 100:1 to 1:100. In yet other embodiments, the molecularly imprinted polymer has a monomer to crosslinker ratio that is from about 1:4.1 to 1:10.
[0018] Another aspect of the disclosure includes a method of making a molecularly imprinted polymer comprising the steps of: providing an aflatoxin template having a Formula (I):
[0000]
[0000] wherein R 1 is selected from H, C 1-6 alkyl, substituted C 1-6 alkyl, and a halo substituted C 1-6 alkyl; R 2 is selected from halo, C 1-6 alkyl, substituted C 1-6 alkyl, a halo substituted C 1-6 alkyl, CH 2 C(O)OR′, and CH(C(O)OR′) 2 ; wherein R′ is selected from H, C 1-6 alkyl, and substituted C 1-6 alkyl; and R 3 is selected from H, C 1-6 alkoxy, and substituted C 1-6 alkyl, or wherein R 1 together with R 2 form a C 4-7 cycloalkyl ring, a halo substituted C 4-7 cycloalkyl ring, an oxo substituted C 4-7 cycloalkyl ring, C 4-7 cycloalkoxy ring a hydroxy substituted C 4-7 cycloalkyl ring and a carboxylic group substituted C 4-7 cycloalkyl; and R 3 is selected from H, C 1-6 alkoxy, and substituted C 1-6 alkyl; combining the aflatoxin template with at least one monomer and one or more crosslinkers; polymerizing the monomer and the one or more crosslinkers to form a molecularly imprinted polymer intermediate; and removing the aflatoxin template from the molecularly imprinted polymer intermediate to form a molecularly imprinted polymer. In particular embodiments, the aflatoxin template comprises 5,7-dimethoxy-cyclopentenon[2,3-c]coumarin 4-(2-chloroethyl)-5,7-dimethoxy coumarin, or combinations thereof. In embodiments, an MIP is prepared by a process as described herein.
[0019] In embodiments, the step of combining of aflatoxin template compound with at least one monomer and one or more crosslinkers comprises mixing the monomer and the crosslinker in a solution of one or more organic solvents. In particular embodiments, the one or more solvents are selected from the group consisting of acetonitrile, toluene, cyclohexane, polyvinyl alcohol in water solution, and a mixture of two or more of acetonitrile, toluene, cyclohexane, polyvinyl alcohol in water solution.
[0020] In other embodiments, a method further comprises adding an initiator. In a particular embodiment, the initiator is azo(bis)-isobutyronitrile (AIBN), wherein free radicals are formed by thermal decomposition of AIBN acting as an initiator. In yet other embodiments, polymerization is initiated by forming free radicals in an organic solvent at a temperature between 55 and 110° C.
[0021] In embodiments, the removal of the aflatoxin template from the molecularly imprinted polymer intermediate comprises washing the molecularly imprinted polymer intermediate with a solvent. In particular embodiments, the organic solvent is selected from the group of ethyl alcohol, methyl alcohol, acetonitrile, toluene, and a mixture of thereof.
[0022] In embodiments, the molecularly imprinted polymer is dried after said one or more washes.
[0023] Another aspect of the disclosure includes a method of sequestering an aflatoxin comprising: providing a molecularly imprinted polymer having a plurality of cavities, wherein at least one of the cavities is made using the aflatoxin template having a Formula I:
[0000]
[0000] wherein R 1 is selected from H, C 1-6 alkyl, substituted C 1-6 alkyl, and a halo substituted C 1-6 alkyl; R 2 is selected from halo, C 1-6 alkyl, substituted C 1-6 alkyl, a halo substituted C 1-6 alkyl, CH 2 C(O)OR′, and CH(C(O)OR′) 2 ; wherein R′ is selected from H, C 1-6 alkyl, and substituted C 1-6 alkyl; and R 3 is selected from H, C 1-6 alkoxy, and substituted C 1-6 alkyl, or wherein R 1 together with R 2 form a C 4-7 cycloalkyl ring, a halo substituted C 4-7 cycloalkyl ring, an oxo substituted C 4-7 cycloalkyl ring, C 4-7 cycloalkoxy ring a hydroxy substituted C 4-7 cycloalkyl ring and a carboxylic group substituted C 4-7 cycloalkyl; and R 3 is selected from H, C 1-6 alkoxy, and substituted C 1-6 alkyl; providing a material, wherein the material optionally contains an aflatoxin; and contacting the molecularly imprinted polymer with the material.
[0024] In embodiments, the material is a liquid, a solid, or a gas. In particular embodiments, the material is selected from the group consisting of soil, a spice, a beverage, a foodstuff, an animal feed, a pharmaceutical composition, a nutraceutical composition, and a cosmetic composition. In a specific embodiment, the material is milk.
[0025] In embodiments, the molecularly imprinted polymer is contacted with the material for at least 1 second.
[0026] In embodiments, a method further comprises separating the molecularly imprinted material from the material. In particular embodiments, the separation of the molecularly imprinted polymer comprises separating by filtration or by centrifugation.
[0027] In embodiments, a method further comprises detecting an amount of aflatoxin complexed with the molecularly imprinted polymer, detecting the amount of aflatoxin in the material after contact with the molecularly imprinted polymer, or both.
[0028] In other embodiments, a method of sequestering an aflatoxin comprises steps of: providing a molecularly imprinted polymer having a plurality of cavities, wherein at least one cavity was made using an aflatoxin template having a Formula (I):
[0000]
[0000] wherein R 1 is selected from H, C 1-6 alkyl, substituted C 1-6 alkyl, and a halo substituted C 1-6 alkyl; R 2 is selected from halo, C 1-6 alkyl, substituted C 1-6 alkyl, a halo substituted C 1-6 alkyl, CH 2 C(O)OR′, and CH(C(O)OR′) 2 ; wherein R′ is selected from H, C 1-6 alkyl, and substituted C 1-6 alkyl; and R 3 is selected from H, C 1-6 alkoxy, and substituted C 1-6 alkyl, or wherein R 1 together with R 2 form a C 4-7 cycloalkyl ring, a halo substituted C 4-7 cycloalkyl ring, an oxo substituted C 4-7 cycloalkyl ring, C 4-7 cycloalkoxy ring a hydroxy substituted C 4-7 cycloalkyl ring and a carboxylic group substituted C 4-7 cycloalkyl; and R 3 is selected from H, C 1-6 alkoxy, and substituted C 1-6 alkyl; b) providing a material containing an aflatoxin; and c) contacting the molecularly imprinted polymer with the material, wherein the molecularly imprinted polymer sequesters at least 40 percent of the aflatoxin by weight per unit of the material. In embodiments, the material is a liquid and the molecularly imprinted polymer sequesters at least 40 percent of the weight of aflatoxin per volume of the material.
DESCRIPTION OF THE DRAWINGS
[0029] FIG. 1 shows the quantity of aflatoxin M1 (AFM1) adsorbed by 1 mg quantity of each MIP in an instant trapping solid phase extraction (SPE) column setup using 1 mL of a 100 ng/L solution of AFM1 in a pH 6.0 ammonium acetate buffer ( ). Also shown are the quantities of AFM1 present in subsequent methanol ( ) and toluene (▪) washed performed after the adsorption step. Quantity of AFM1 adsorbed vs. quantity of AFM1 released from the material can be quantified.
[0030] FIG. 2 shows average AFM1 adsorption averaged over multiple time points for the indicated MIPs and corresponding non-imprinted polymers (NIPs) (varying from 0.001%-0.1%)sing free flowing MIP/NIP over 6 periods of time, from 5 to 500 minutes with a 90 ng/L AFM1 10 mL solution. Adsorption efficacy was measured by quantitation of the mycotoxin remaining in the supernatant ( ) and eluting from the MIP/NIP after methanol wash ( ) which defined adsorption efficacy and selectivity. Due to the fact that there is instant adsorption, the AFM1 adsorption quantities for each time point (15, 30, 60, 90 minutes and 18 hrs) were averaged for each product. All test tubes were then centrifuged for 10 minutes at 3,000 rpm and a transferred into UPLC vial for analysis. The powder (MIP or NIP) was then transferred to a 2 mL Eppendorf tube where 1 mL of methanol was added and vortexed for approximately three seconds.
[0031] FIG. 3 shows average AFM1 adsorption averaged for MIP-003(varying from 0.001%-0.1%) in 10 mL of raw milk spiked with a concentration of 225 ng/L AFM1.
[0032] FIG. 4 is a schematic diagram of a synthesis of an aflatoxin template.
[0033] FIG. 5 shows results for the instant trapping of AFM1 by MIP-005 at various inclusion rates (ranging from 0.001%-0.1%) in an SPE column setup at room temperature.
DEFINITIONS
[0034] As used herein, the term “about,” when used in reference to a particular recited numerical value, means that the value may vary from the recited value by no more than 1%. For example, as used herein, the expression “about 100” includes 99 and 101 and all values in between (e.g., 99.1, 99.2, 99.3, 99.4, etc.).
[0035] As used herein, the term “molecularly imprinted polymer(s)” or “MIP(s)” refers to synthetic polymers that selectively bind to one or more aflatoxins. In embodiments, a MIP exhibits high enantioselectivity and low substrate selectivity, wherein the MIP interacts with the template aflatoxin racemate as well as its corresponding analogs, such as naturally occurring aflatoxins. In embodiments, the MIP has a higher enantioselectivity than the corresponding non-imprinted polymer for the binding of aflatoxins. In embodiments, the MIP selectively binds to aflatoxins and does not bind to other mycotoxins. In embodiments, the MIP binds to one or more of aflatoxins B1, B2, G1, G2, M1, M2, P1, and Q1. In embodiments, the MIP selectively binds aflatoxin B1 and aflatoxin M1.
[0036] In embodiments, a polymer is crosslinked to generate cavities, at least one of which is made using an aflatoxin template of Formula (I). In some embodiments, at least one cavity provides a site of interaction for reversible binding with an aflatoxin template of Formula (I) and/or aflatoxins. In general, MIPs are constructed using: i) a templates (e.g., aflatoxin template) that mimic the structure, size, shape and/or other chemical characteristics of one or more targeted compound(s) (e.g., aflatoxins) and ii) other components, such as monomers and/or cross linking reagents. For example, one or more aflatoxin templates are incorporated into a pre-polymeric mixture comprising monomers and a crosslinker. The mixture is then polymerized to form a “molecularly imprinted polymer intermediate” or “MIP intermediate” comprising a crosslinked polymer and the aflatoxin template(s). Once the polymer has formed, the aflatoxin template(s) is/are removed, leaving behind complementary cavities having a chemical and/or physical capacity to form a complex with one or more aflatoxins or other compounds resembling aflatoxin. Such regions (e.g., cavities or other regions) are tailored for binding one or more aflatoxins giving rise to a high affinity for such aflatoxin containing compounds and selectivity. While aflatoxin template compounds are used to form molecularly imprinted polymers, in some embodiments, the MIPs may have a high affinity for a class of compounds that is distinct from but similar to one or more aflatoxins. For example, a MIP may bind a number of compounds containing molecules that are similar in shape, size, charge density, geometry or other physical or chemical properties to one or more aflatoxins.
[0037] As used herein, the term “non-imprinted polymer” or “NIP” refers to synthetic polymers that are formed without the presence of a template compound (e.g., aflatoxin template). Such polymers, which have no enantioselectivity nor substrate selectivity, and might interact with any molecules susceptible to generate hydrogen-bounding, ionic interaction, electrostatic interaction with the components of the NIP. NIPs are involved in non-specific non-covalent surface interactions of lower stability than when a specific cavity is available from the imprinting process in the MIP network to target a specific compound (e.g., AFB1, AFM1). In embodiments, a “corresponding” NIP refers to a synthetic polymer synthesized with the same monomer and crosslinker as a MIP but without the use of a template (e.g., aflatoxin template).
[0038] As used herein, the term “polymer”, refers to a molecule (macromolecule) composed of repeating structural units (e.g. monomer) typically connected by covalent chemical bonds forming a network. In embodiments, a polymer is formed by crosslinking of monomers forming primary chains or structural units that assemble in a network.
[0039] As used herein, the term “aflatoxin template(s)” refer(s) to one or more synthetically constructed molecule(s) that mimic the structure, size, shape and/or other chemical characteristics of one or more natural aflatoxins. The disclosure is not limited by the type of aflatoxin template utilized, that can be either synthetic or natural. Indeed a variety of aflatoxins may bind to MIPs generated using an aflatoxin template compound including, but not limited to, aflatoxin B1, B2, G1, G2, M1, P1, Q1, and other aflatoxins described herein.
[0040] As used herein, the term “monomer(s)”, refers to a molecule that may become chemically bonded to other monomers to form a polymer.
[0041] As used herein, the terms “crosslink” and “crosslinker”, refer to molecules that contain two, three or four double-bonds that are capable of attaching to two or more monomers to form a polymer network.
[0042] As used herein, the term “structural unit”, refers to a building block of a polymer chain, and related to the repeat unit.
[0043] As used herein, the term “anionic” or “anion” refers to an ion that has a negative charge.
[0044] As used herein, the term “cationic” or “cation” refers to an ion that has a positive charge. This term can refer to polymeric compounds, such as molecularly imprinted polymers, that contain a positive charge.
[0045] As used herein, the term “acid” as used herein refers to any chemical compound that can donate proton(s) and/or accept electron(s). As used herein, the term “base” refers to any chemical compound that can accept proton(s) and/or donate electron(s) or hydroxide ions. As used herein, the term “salt” refers to compounds that may be derived from inorganic or organic acids and bases.
[0046] As used herein, the term “bleeding”, refers to a remaining fraction of the template still in association with the MIP after several washing stages of the MIP, and that continues to dissociate from the MIP and interfere with its adsorption activity.
[0047] As used herein, the term “porogenic/porogen”, refers to a substance, molecule, buffer, solvent, (e.g., toluene, xylene, ethylbenzene) used to change the size of the cavities in a polymer (e.g., cavities of a MIP). In embodiments, a polymer to porogen ratio is directly correlated to the amount of porosity of the final structure and dictates the size of the polymer agglomerates formed.
[0048] As used herein, the term “inclusion rate” refers to the amount of MIP provided per unit of material (e.g. milk), for example, in a unit of weight of the polymer as compared to a unit of volume of the material or in a unit of weight of the polymer as compared to a unit per weight of the material.
[0049] As used herein, the term “cavity(ies)”, refer(s) to a space, pore, or other opening that is/are within the MIP and that are sized and/or shaped to allow an aflatoxin to be bound therein. In embodiments, a cavity is formed in a crosslinked polymer by polymerizing the polymer in the presence of the aflatoxin template and removing the aflatoxin template to form the cavity in the crosslinked polymer, which is now an MIP.
[0050] As used herein, the term “polymerization”, refers to a process of reacting monomer molecules together in a chemical reaction to form three-dimensional networks or polymer chains and agglomerated polymers chains.
[0051] As used herein, the term “precipitation”, refers to the formation of a solid in a solution during a chemical reaction. When the reaction occurs, the solid formed is called the precipitate, and the liquid remaining above the solid is called the supernatant.
[0052] As used herein, the term “centrifugation” refers to the process of separating molecules by size or density using centrifugal forces generated by a spinning rotor that puts an object in rotation around a fixed axis, applying a force perpendicular to the axis. The centrifuge works using the sedimentation principle, where the centripetal acceleration is used to evenly distribute substances of greater and lesser density into different layers of density.
[0053] As used herein, the term “concentration” refers to the amount of a substance per defined space. Concentration usually is expressed in terms of mass per unit of volume. To dilute a solution, one must add more solvent, or reduce the amount of solute (e.g., by selective separation, evaporation, spray drying, freeze drying). By contrast, to concentrate a solution, one must reduce the amount of solvent.
[0054] As used herein, the term “layer” refers to a usually horizontal deposit organized in stratum of a material forming an overlying part or segment obtained after separation by centrifugation or sedimentation in relation with the density properties of the material.
[0055] As used herein, the term “purified” or “to purify” refers to the removal of foreign components from a sample. When used in a chemical context “purified” or “to purify” refers to the physical separation of a chemical substance of interest from undesired substances. Commonly used methods for purification of organic molecules, include, but are not limited to the following: affinity purification, mechanical filtration, centrifugation, evaporation, extraction of impurity, dissolving in a solvent in which other components are insoluble, crystallization, adsorption, distillation, fractionation, sublimation, smelting, refining, electrolysis and dialysis.
[0056] As used herein, the term “drying” refers to any kind of process that reduces or eliminates the amount of liquid in a substance.
[0057] As used herein, the term “washing” refers to the removal (e.g., using any type of solute (e.g., distilled water, buffer, or solvent, or mixture)) of impurities or soluble unwanted component of a preparation (e.g., a MIP may be washed to remove the aflatoxin template components from the sample).
[0058] As used herein, the term “analyte” refers to an atom, a molecule, a substance, or a chemical constituent. In general, an analyte, in and of itself is not measured, rather, aspects or properties (physical, chemical, biological, etc.) of the analyte are determined using an analytical procedure, such as Ultra Performance Liquid Chromatography (abbreviated as UPLC). For example, in general one does not measure a “chair” (analyte-component) in and of itself, but, the height, width, etc. of a chair are measured. Likewise, in general one does not measure an aflatoxin but rather measures one or more properties of the aflatoxin (e.g., aflatoxins fluorescence or molecular weight, related for example, to its stability, concentration, or biological activity).
[0059] As used herein, the term “sample” is used in a broad sense including a specimen from any source (e.g., synthetic, biological and environmental samples). Synthetic samples include any material that is artificially produced (e.g., MIP). Biological samples may be obtained from animals (including humans) and encompass fluids, solids, tissues, and gases. Biological samples include blood products, such as plasma, serum and the like. Environmental samples include environmental material such as surface matter, soil, water, crystals and industrial samples.
[0060] As used herein, the term “Ultra Performance Liquid Chromatography” or “UPLC” refers to a form of liquid chromatography to separate compounds. The compounds are dissolved in a solution. Compounds are separated by injecting a sample mixture onto a column, through which a solvent or solvent mixture has been flowing at a specific pressure, to elute components of the mixture, from the column. UPLC instruments comprise one or more reservoirs of mobile phases, a pump, an injector, a separation column, and a detector. The presence of analytes in the column effluent is recorded by quantitatively detecting a change in refractive index, UV-VIS absorption at a set wavelength, fluorescence after excitation with a suitable wavelength, electrochemical response, or mass to charge ratio based on the molecular weight of an analyte in a charged state.
[0061] As used herein, the term “signal” is used generally in reference to any detectable process that indicates that a reaction has occurred (for example, binding of antibody to antigen). Signals can be assessed qualitatively as well as quantitatively. Examples of types of “signals” include, but are not limited to, radioactive signals, fluorometric signals, colorimetric product/reagent signals, mass to charge ratio measure.
[0062] As used herein, the terms “absorb” and “absorption” refer to the process by which a material “takes in” or “sucks up” another substance. For example, “absorption” may refer to the process of taking in or assimilating substances into cells or across the tissues and organs through diffusion or osmosis (e.g., absorption of nutrients by the digestive system or absorption of drugs into the blood stream).
[0063] As used herein, the terms “adsorb” and “adsorption” refer to a process that occurs when a material is captured by, sequestered by, bound by, trapped by, and/or accumulated by (e.g., on the surface of) a composition (adsorbent), or to a process in which a composition (e.g., MIP) binds to a target molecule (e.g., one or more aflatoxins) in a sample (e.g., for removing the target molecule from a sample).
[0064] As used herein, the terms “sorb” and “sorption” refer to both adsorption and absorption.
[0065] As used herein, the terms “sequester”, “capture”, “trap”, “adsorb”, or “bind” refer to physical association (e.g., via bonding (e.g., hydrogen boding, ionic bonding, covalent bonding or other type of bonding) of two or more entities that come into contact with one another (e.g., thereby forming a complex). Exemplary forms of associations include, but are not limited to, hydrogen bonding, coordination, and ion pair formation. Sequestering interactions may involve a variable number of chemical interactions (e.g., chemical bonds) depending on the stereochemistry and geometry of each entity (e.g., further defining the specificity of the sequestering). When two or more entities are interacting they may be sequestered by way of chemical bonds or physical bonds but may also be associated via charge, dipole-dipole or other type of interactions.
[0066] As used herein, the terms “sequestering agent”, “capturing agent”, “trapping agent”, “adsorbing agent” and/or “binding agent”, refer to an entity that is capable of forming a complex with a second entity.
[0067] As used herein, the term “complex” refers to an entity formed by association between two or more separate entities (e.g., association between two or more entities wherein the entities are the same or different (e.g., same or different chemical species). The association may be via a covalent bond or a non-covalent bond (e.g., via van der Waals, electrostatic, charge interaction, hydrophobic interaction, dipole interaction, and/or hydrogen bonding forces (e.g., urethane linkages, amide linkages, ester linkages, and combination thereof)).
[0068] As used herein, the term “bind” refers to a close association between two or more separate entities (e.g., association between two or more entities wherein the entities are the same or different (e.g., same or different chemical species). The association may be via a covalent bond or a non-covalent bond (e.g., via van der Waals, electrostatic, charge interaction, hydrophobic interaction, dipole interaction, and/or hydrogen bonding forces (e.g., urethane linkages, amide linkages, ester linkages, and combination thereof)). As used herein, the term “close” refers to touching or near touching.
[0069] As used herein, the term “effective amount” refers to the amount of a composition (e.g., MIP) sufficient to accomplish beneficial or desired results. An effective amount can be administered and/or combined with another material in one or more administrations, applications or dosages and is not intended to be limited to a particular formulation or administration route.
[0070] As used herein, the term “animal” refers to any one or more species in the kingdom of animalia. This includes, but is not limited to livestock, other farm animals, domestic animals, pet animals, marine and freshwater animals, and wild animals.
[0071] As used herein, the term “feedstuffs” refers to material(s) that are consumed by a human or animal that contribute energy and/or nutrients to the subject. Examples of feedstuffs include, but are not limited to, dairy products, juices, grains, including but not limited to distillers grains, fruits, vegetables, meats, Total Mixed Ration (TMR), forage(s), pellet(s), concentrate(s) of any of the previous items, premix(es) or coproduct(s) of any of the previous products, molasses, fiber(s), fodder(s), grass(es), hay, kernel(s), leaves, meals made from any of the previous products, soluble(s) and supplement(s) containing any of the previous products.
[0072] As used herein, the term “mycotoxin” refers to toxic and/or carcinogenic compound(s) produced by various fungal species. In embodiments, the mycotoxin is an aflatoxin.
[0073] As used herein, the term “mycotoxicosis” refers to a condition in which mycotoxins pass the resistance barriers of a human or animal body. Mycotoxicosis can be considered either an infection or a disease and may have a deleterious effect on those afflicted.
[0074] As used herein, the term “toxic” refers to any detrimental, deleterious, harmful, or otherwise negative effect(s) on an animal or human, including, but not limited to a cell or a tissue of such animal or human. As used herein the terms “detrimental”, “deleterious”, “harmful”, or “otherwise negative” with respect to “effect” can be determined by comparing the same cell or tissue of an animal or human prior to the contact or administration of a toxin or toxicant and after such contact and detecting an undesirable change in such cell or tissue when making such comparison.
[0075] As used herein, the term “traceability” refers to the property of the result of a measurement or the value of a standard whereby it can be related to stated references, usually national or international standards, through an unbroken chain of comparisons, all having stated uncertainties. It is the practical application of general metrology concepts to chemical measurements and provides the terminology, concepts and strategy for ensuring also that analytical chemical measurements are comparable. It measures the uniquely identifiable entities in a way that is verifiable. Traceability measures are utilized, among other things, to interrelate the chronology, location, and/or application of an item by means of documented recorded identification.
[0076] As used herein, the term “alkyl”, by itself or as part of another substituent, refers to, unless otherwise stated, a straight or branched chain, or cyclic hydrocarbon radical, or combination thereof, which is fully saturated, having the number of carbon atoms designated (e.g., C1-C6 means one to six carbons). Examples of alkyl groups include, but are not limited to, methyl, ethyl, n-propyl, isopropyl, n-butyl, t-butyl, isobutyl, cyclohexyl, homologs and isomers of, for example, n-pentyl, n-hexyl, and the like.
[0077] As used herein, the term “heteroalkyl”, by itself or as part of another substituent, refers to, unless otherwise stated, a straight or branched chain, or cyclic hydrocarbon radical, or combination thereof, which is fully saturated, having the number of carbon atoms designated (e.g., C1-C6 means one to six carbons) in which one of the carbon atom is replaced by a heteroatom. In embodiments a heteroatom is an oxygen.
[0078] As used herein, the term “substituted alkyl”, unless otherwise stated, refers to a straight or branched chain, or cyclic hydrocarbon radical, or combination thereof, which is fully saturated, having the number of carbon atoms designated (e.g., C1-C6 means one to six carbons) and having a substitution of at least one of the H atoms. Examples of alkyl groups include methyl, ethyl, n-propyl, isopropyl, n-butyl, t-butyl, isobutyl, cyclohexyl, homologs and isomers of, for example, n-pentyl, n-hexyl, and the like. Examples of substituents that can be used in a substituted alkyl include, but are not limited to, halogens, carboxy, and hydroxyl groups. As used herein, the term “halo substituted alkyl”, by themselves or in combination with other terms, unless otherwise stated, refers to a substituted alkyl wherein a halo atom is used to replace at least one of the H atoms.
[0079] As used herein, the terms “cycloalkyl” and “heterocycloalkyl” by themselves or in combination with other terms, refer to, unless otherwise stated, cyclic versions of “alkyl” and “heteroalkyl” respectively. Additionally, for heterocycloalkyl, a heteroatom can occupy the position at which the heterocycle is attached to the remainder of the molecule.
[0080] The terms “halo” or “halogen,” by themselves or in combination with other terms, mean, unless otherwise stated, a fluorine, chlorine, bromine, or iodine atom. Additionally, terms such as “haloalkyl”, are meant to include one or more substituted alkyl groups with halogen atoms that can be the same or different, in a number ranging from one to (2m+1), where m is the total number of carbon atoms in the alkyl group. Thus, the term “haloalkyl” includes monohaloalkyl (alkyl substituted with one halogen atom) and polyhaloalkyl (alkyl substituted with halogen atoms in a number ranging from two to (2m+1) halogen atoms).
[0081] The term “alkoxy,” refers to one or more alkyl groups attached to the remainder of the molecule via an oxygen atom.
DETAILED DESCRIPTION
[0082] This disclosure describes aflatoxin template(s), compounds containing one or more such aflatoxin templates, and molecularly imprinted polymers made using such compounds, and methods of making and using such templates and compounds.
Aflatoxin Template(s) and Intermediates
[0083] In embodiments, aflatoxin templates described herein are structural analogs to aflatoxin molecules. In other embodiments, aflatoxin template(s) are similar in shape, size, charge density, geometry and/or other physical or chemical properties to one or more aflatoxins. In specific embodiments, an aflatoxin template comprises a coumarin moiety, at least one alkoxy moiety, and a carbonyl moiety. Aflatoxins molecules include one or more types of aflatoxin B1, B2, G1, G2, M1, M2, P1, and Q1.
[0084] In embodiments, Aflatoxin B1 (AFB1) was used as a model to create a structural analog using the synthesis described herein. Aflatoxin analogs are advantageous because they reduce or eliminate the need to handle large quantities of toxic aflatoxins and to prevent bleeding of aflatoxins out of the polymer. In embodiments, at least two different aflatoxin templates are prepared. In embodiments, aflatoxin templates have reduced or no toxicity as compared to naturally occurring aflatoxins.
[0085] An aflatoxin template has or comprises a Formula (I):
[0000]
[0000] wherein R 1 is selected from H, C 1-6 alkyl, substituted C 1-6 alkyl, and a halo substituted C 1-6 alkyl; R 2 is selected from halo, C 1-6 alkyl, substituted C 1-6 alkyl, a halo substituted C 1-6 alkyl, CH 2 C(O)OR′, and CH(C(O)OR′) 2 , R′ is selected from H, C 1-6 alkyl, substituted C 1-6 alkyl, and a halo substituted C 1-6 alkyl; and R 3 is selected from H, C 1-6 alkoxy, and substituted C 1-6 alkyl. In related embodiments, R′ is one or more substituents selected from a group consisting of halo, oxo, hydroxy and alkoxy.
[0086] In embodiments, R 1 , R 2 , R 3 , and R′ may independently be alkyl groups. An alkyl, refers to a straight or branched chain, or cyclic hydrocarbon radical, or combination thereof, which is fully saturated, having the number of carbon atoms designated (e.g., C1-C6 means one to six carbons). Examples of alkyl groups include methyl, ethyl, n-propyl, isopropyl, n-butyl, t-butyl, isobutyl, cyclohexyl, homologs and isomers of, for example, n-pentyl, n-hexyl, and the like.
[0087] In embodiments, R 1 , R 2 , R 3 , and R′ may independently be substituted alkyl groups. A substituted alkyl is a straight or branched chain, or cyclic hydrocarbon radical, or combination thereof, which is fully saturated, having the number of carbon atoms designated (e.g., C1-C6 means one to six carbons) and having a substitution of at least one of the H atoms. Examples of alkyl groups include methyl, ethyl, n-propyl, isopropyl, n-butyl, t-butyl, isobutyl, cyclohexyl, homologs and isomers of, for example, n-pentyl, n-hexyl, and the like. Examples of substitutions include halogens, carboxy, and hydroxyl groups.
[0088] In embodiments, R 1 , R 2 , R 3 , and R′ may independently be a halogen. A halo group or halogen, refers to a fluorine, chlorine, bromine, or iodine atom. Additionally, haloalkyl includes alkyl substituted with one or more halogen atoms, each of which can be the same or different, in a number ranging from one to (2m+1), where m is the total number of carbon atoms in the alkyl group. Examples include monohaloalkyl (alkyl substituted with one halogen atom) and polyhaloalkyl (alkyl substituted with halogen atoms in a number ranging from two to (2m+1) halogen atoms). In embodiments, the halogen is a chlorine or fluorine.
[0089] In embodiments, R 3 may independently be an alkoxy. An alkoxy refers to those alkyl groups attached to the remainder of the molecule via an oxygen atom. Examples include methoxy, ethoxy and the like.
[0090] In some example embodiments, an aflatoxin template has or comprises the Formula:
[0000]
[0000] In a specific embodiment, an aflatoxin template is 4-(2-chloroethyl)-5,7-dimethoxy coumarin.
[0091] In other related embodiments, an aflatoxin template comprises an isolated compound having a formula selected from the group consisting of
[0000]
[0000] and combinations thereof.
[0092] In embodiments, an aflatoxin template comprises an isolated compound selected from the group consisting of 2-((5,7-dimethoxy-2-oxo-2H-chromen-4yl)methyl) malonic acid, 3-(5,7-dimethoxy-2-oxo-2H-chromen-4yl)propanoic acid, diethyl 2-((5,7-dimethoxy-2-oxo-2H-chromen-4yl)methyl) malonate and combinations thereof.
[0093] In an alternative embodiment, an aflatoxin template has or comprises Formula
[0000]
[0000] wherein R 1 together with R 2 form a C 4-7 cycloalkyl ring, a halo substituted C 4-7 cycloalkyl ring, an oxo substituted C 4-7 cycloalkyl ring, C 4-7 cycloalkoxy ring a hydroxy substituted C 4-7 cycloalkyl ring and a carboxylic group substituted C 4-7 cycloalkyl; and R 3 is selected from H, C 1-6 alkoxy, and substituted C 1-6 alkyl.
[0094] In embodiments, cycloalkyl and heterocycloalkyl represent, cyclic versions of alkyl and heteroalkyl respectively. Additionally, for heterocycloalkyl, a heteroatom can occupy the position at which the heterocycle is attached to the remainder of the molecule.
[0095] In other related embodiments, an aflatoxin template has or comprises the Formula:
[0000]
[0096] In a specific embodiment, the aflatoxin template is 5,7-dimethoxycyclo pentenon[2,3-c]coumarin.
Aflatoxin Template Synthesis
[0097] Aflatoxin templates and compounds containing such aflatoxin templates as described herein can be prepared by a variety of methods. The exemplary methods described herein provide processes (e.g., a synthetic process) and materials that allow large scale production of compounds containing one or more aflatoxin templates that are not only economical (e.g., that enables realizable, large scale production in an economically achievable manner), but that also use reagents that generally can be more readily available than reagents used to make mycotoxin templates previously.
[0098] In embodiments, a method of synthesis of an aflatoxin template of Formula (I) comprises reacting 3,5-dimethoxy phenol with ethyl 4-chloroacetoacetate in acid to form 4-(2-chloroethyl)-5,7-dimethoxy coumarin. In other embodiments, the compound 4-(2-chloroethyl)-5,7-dimethoxy coumarin is isolated and is used to form a MIP.
[0099] In embodiments, a method of synthesis of an aflatoxin template comprises suspending a monoacid according to the Formula of:
[0000]
[0000] in polyphosphoric acid and heating to at least 50° C.; cooling the reaction mixture below 50° C. and adding an aqueous to obtain an aflatoxin template according to the Formula of:
[0000]
[0000] This aflatoxin template is isolated and used to form a MIP.
[0100] In embodiments, a method of providing a monoacid comprises suspending a diacid according to a Formula of:
[0000]
[0000] in a solvent and heating to at least 100° C., or about 100 to 140° C.
[0101] In embodiments, a method of synthesis of an aflatoxin template comprises deprotecting a diester analog (i.e. 2-((5,7-dimethoxy-2-oxo-2H-chromen-4-yl)methyl)malonate) according to a Formula of:
[0000]
[0000] using a base (e.g. NaOH) in a solvent (e.g. ethanol) and heating to at least 60° C.; to form a diacid analog; and precipitating the diacid analog to isolate the aflatoxin template according to a Formula of:
[0000]
[0102] In embodiments, a method of synthesis of diester intermediate (i.e., diethyl 2-((5,7-dimethoxy-2-oxo-2H-chromen-4-yl)methyl)malonate) comprises combining 4-(2-chloroethyl)-5,7-dimethoxy coumarin according to a Formula of:
[0000]
[0000] with diethyl malonate, potassium iodide, and a crown ether to form a diester analog; and
[0103] precipitating the diester analog to isolate the aflatoxin template intermediate according to a Formula of:
[0000]
[0104] In embodiments, a method of synthesis of an aflatoxin template of Formula (I) comprises deprotecting diethyl 2-((5,7-dimethoxy-2-oxo-2H-chromen-4-yl)methyl)malonate to form a diacid analog, and precipitating a diacid analog according to a Formula of:
[0000]
[0000] suspending the diacid analog in a solvent and heating to 100° C., or 100 to 140° C. and precipitating a monoacid according to a Formula of:
[0000]
[0000] suspending the monoacid in an acid and heating to at least 50° C., cooling the reaction mixture to below 50° C., and adding aqueous solution to obtain
[0000]
[0105] Referring now to FIG. 4 where aflatoxin template analogs and intermediate compounds were formed by condensation of 3,5-dimethoxyphenol with ethyl-4-chloroacetoacetate in presence of H 2 SO 4 in toluene to form a chlorinated analog, 4-(2-chloroethyl)-5,7-dimethoxy coumarin. In this example, 4-(2-chloroethyl)-5,7-dimethoxy coumarin is combined with diethyl malonate, potassium iodide, and a crown ether in acetonitrile to form a mixture. Once the mixture is formed, potassium t-butoxide is added to the mixture to form a diester with the Formula diethyl 2-((5,7-dimethoxy-2-oxo-2H-chromen-4-yl)methyl)malonate.
[0106] Upon the formation of the diethyl 2-((5,7-dimethoxy-2-oxo-2H-chromen-4-yl)methyl)malonate, in this embodiment, a diacid is formed by deprotecting diethyl 2-((5,7-dimethoxy-2-oxo-2H-chromen-4-yl)methyl)malonate using a base in alcohol. The diacid, having a Formula of:
[0000]
[0000] is heated to at least 135° C. in a solvent. In this embodiment, the diacid is then converted to its monoacid by partial decarboxylation in xylene at reflux temperature. In at least this embodiment, the monoacid was subjected to cyclization using polyphosphoric acid to yield the final AFT-1 aflatoxin template (AFT-1) with the Formula of:
[0000]
[0107] It should be appreciated that the chemical formula used, must allow for molecularly imprinted polymer intermediates, described in further detail below, to reversibly bind the aflatoxin template to the MIP. Additionally, the aflatoxin template contained in the aflatoxin template must provide a molecularly imprinted polymer intermediate with a cavity that retains a high level of affinity for one or more aflatoxins, such as aflatoxin B1.
[0108] In embodiments, a composition comprising an aflatoxin template and a carrier is provided. In embodiments, the composition includes an effective amount of the aflatoxin template to form a MIP with the desired characteristics (e.g. typically represented as an amount in relation to the amount of the monomer, a ratio). The compositions are formulated with suitable carriers, excipients, and other agents that provide suitable transfer, delivery, stability, and functionality of the aflatoxin template.
Molecularly Imprinted Polymers
[0109] In embodiments, a molecularly imprinted polymer comprises a crosslinked polymer comprising a monomer or made from a monomer, wherein the crosslinked polymer has a plurality of cavities, and at least one of the cavities is made with an aflatoxin template having a Formula (I):
[0000]
[0000] wherein R 1 is selected from H, C 1-6 alkyl, substituted C 1-6 alkyl, and a halo substituted C 1-6 alkyl; R 2 is selected from halo, C 1-6 alkyl, substituted C 1-6 alkyl, a halo substituted C 1-6 alkyl, CH 2 C(O)OR′, and CH(C(O)OR′) 2 ; wherein R′ is selected from H, C 1-6 alkyl, and substituted C 1-6 alkyl; and R 3 is selected from H, C 1-6 alkoxy, and substituted C 1-6 alkyl; or wherein R 1 together with R 2 form a C 4-7 cycloalkyl ring, a halo substituted C 4-7 cycloalkyl ring, an oxo substituted C 4-7 cycloalkyl ring, C 4-7 cycloalkoxy ring a hydroxy substituted C 4-7 cycloalkyl ring and a carboxylic group substituted C4-7 cycloalkyl; and R 3 is selected from H, C 1-6 alkoxy, and substituted C 1-6 alkyl.
[0110] In embodiments, at least one cavity provides for binding of the aflatoxin template of Formula (I). In an embodiment, a MIP selectively binds one or more aflatoxin templates. In embodiments, a MIP selectively binds one or more types of aflatoxins, for example, aflatoxins B1, B2, G1, G2, M1, M2, P1, and Q1. In embodiments, the affinity and/or selectivity of the MIP for an aflatoxin is compared to a corresponding NIP.
[0111] In some cases, all or a portion of the binding of the aflatoxin template or aflatoxin is reversible under certain conditions. After an MIP intermediate is formed, an aflatoxin template is removed using a solvent. In embodiments, a solvent is selected that can disrupt the interaction of the aflatoxin template with the polymer and has a similar polarity and/or solubility as the aflatoxin template. In embodiments, the solvent is a polar solvent.
[0112] Alternatively, after the MIP has bound aflatoxin from a material and is separated from the material, in embodiments, the bound aflatoxin can be removed in order to reuse the MIP. In embodiments, at least a portion of the bound aflatoxin and/or aflatoxin template is removable from the MIP using a solvent, such as a polar solvent. In embodiments, a solvent is selected that can disrupt the interaction of the aflatoxin with the polymer and has a similar polarity and/or solubility as the aflatoxin. In embodiments, a solvent is selected from the group of ethyl alcohol, methyl alcohol, acetonitrile, toluene, and a mixture of thereof. In some embodiments, about 25% or less of the aflatoxin bound to the MIP is released based on weight per volume in the presence of a solvent. In embodiments, the MIP releases 25%, 20%, 15%, 10%, 5%, or 1% or less by weight of one or more aflatoxins sequestered from a material, for example, in polar solvent. In contrast, about 90% or more aflatoxin is released from a corresponding NIP in the presence of the same solvent.
[0113] In embodiments, the MIP binds to the aflatoxin template with a chemical and/or physical interaction. In other embodiments, the polymer network forming the cavities binds to the aflatoxin template with a covalent or noncovalent bond. In embodiments, a MIP comprises micropores of about 20 Angstroms or less, and/or meso- and macropores between about 20 and 2000 Angstroms. In embodiments, an aflatoxin template has a molar volume of at least 300 cubic Angstroms. In other embodiments, the MIP has one or more cavities or pores that have a molar volume of at least 300 cubic Angstroms.
[0114] In embodiments, an aflatoxin template has a formula of Formula (I) as described herein. In a specific embodiment, the aflatoxin template of Formula (I) is selected from the group consisting of 4-(2-chloroethyl)-5,7-dimethoxy coumarin, 5,7-dimethoxycyclo pentenon[2,3-c]coumarin, and combinations thereof. In embodiments, a molecularly imprinted polymer is synthesized using more than one of the aflatoxin templates of Formula (I).
[0115] In embodiments, a polymer is formed from a monomer. A monomer is selected taking into account structural features of the aflatoxin template in order to assess which monomer or combination of monomers is most likely to form interactions (e.g., covalent, non-covalent, ionic, hydrogen bonds, hydrophobic interactions, van der Waals interactions) with the template. In the case of polymeric or oligomeric compounds that are to be utilized in vivo (e.g., as therapeutics or diagnostics, or as consumable sequestering components of animal feed or human foodstuffs), it is important to select monomers that are non-toxic and which exhibit suitable in vivo stability and solubility. Preferred examples for an aflatoxin MIP include, but are not limited to, acrylamides and methacrylates. Alternatively, the polymer may be treated post-polymerization to enhance the template solubility, e.g., by reaction with suitable organic or inorganic reagents.
[0116] Classes of monomers and specific monomers (e.g., utilized in MIP synthesis methods of the disclosure) include, but are not limited to, the following classes and derivatives thereof: acrylic acid and derivatives (e.g., 2-bromoacrylic acid, acryloyl chloride, N-acryloyl tyrosine, N-acryoyl pyrrolidinone, trans-2-(3-pyridyl)-acrylic acid), acrylates (e.g., alkyl acrylates, allyl acrylates, hydroxypropyl acrylate), methacrylic acid and derivatives (e.g., itaconic acid, 2-(trifluoromethyl) propenoic acid), methacrylates (e.g., methyl methacrylate, hydroxyethyl methacrylate, 2-hydroxyethyl methacrylate, 3-sulfopropyl methacrylate sodium salt, ethylene glycol monomethacrylate), styrenes (e.g., (2, 3 and 4)-aminostyrene, styrene-4-sulfonic acid, 3-nitrostyrene, 4-ethystyrene), vinyls (e.g., vinyl chloroformate, 4-vinylbenzoic acid, 4-vinylbenzaldehyde, vinyl imidazole, 4-vinylphenol, 4-vinylamine, acrolein), vinylpyridines (e.g., (2, 3, and/or 4)-vinylpyridine, 3-butene 1,2-diol), boronic acids (e.g., 4-vinylboronic acid), sulfonic acids (e.g., 4-vinylsulfonic acid, acrylamido-2-methyl-1-propane-sulphonic acid), metal chelators (e.g., styrene iminodiacetic acid), acrylamides and derivatives (e.g., N-methyl acrylamide), methacrylamides and derivatives (e.g., N,N-dimethyl acrylamide, N-(3-aminoprpoyl) methacrylamide), alkenes (e.g., 4-pentenoic acid, 3-chloro-1-phenyl-1-propene) (meth)acrylic acid anhydride and derivatives (e.g., methacrylic anhydride), silicon-containing monomers (e.g., (3-methacryloxypropyl) trimethoxy silane, tetramethyldisiloxane), polyenes (e.g., isoprene, 3-hydroxy-3,7,11-trimethyl-1,6,10-dodecatriene), azides (e.g., 4-azido-2,3,5,6-tetrafluorobenzoic acid), thiols (e.g., allyl mercaptan). Acrylate terminated or otherwise unsaturated urethanes, carbonates and epoxies can also be used in embodiments of the present invention, as can silicon-based monomers.
[0117] If utilized, one or more crosslinking agents will preferably be one or several polymeric or oligomeric compounds, or a compound that provides for cleavage under specific conditions. Crosslinking agents that lend rigidity to the subject polymeric compounds are known to those skilled in the art, and include, but are not limited to, di-, tri-, tetra- and penta-functional acrylates, methacrylates, acrylamides, vinyls, allyls, and styrenes. Specific examples of cross-linking agents include but are not limited to p-divinylbenzene, ethylene glycol dimethacrylate (abbreviated as EGDMA), tetramethylene dimethacrylate (abbreviated as TDMA), N,N′-methylene bisacrylamide (MDAA),N,N′-1,3-phenylenebis(2-methyl-2-propenamide)(PDBMP),2,6-bisacryloylamidopyridine, 1,4-diacryloyl piperazine (abbreviated as DAP), 1,4-phenylene diacrylamide, and N,O-bisacryloyl-L-phenylalaninol. Examples of reversible, cleavable crosslinkers include, but are not limited to, N,N′-bis-(acryloyl) cystamine, N,N-diallyltartardiamide, N,N-(1,2-dihydroxyethylene)bisacrylamide, N1-((E)-1-(4-vinylphenyl) methylidene)-4-vinylanilene, allyl disulfide, and bis(2-methacryloyloxyethyl))disulfide. In preferred embodiments, ethylene glycol dimethacrylate is used as a cross-linking agent. Although the preferred cross-linking monomer is ethylene glycol dimethacrylate, embodiments of the present invention are not limited to this agent, and other cross-linking monomers may be used, such as, divinylbenzene and trimethylolpropane trimethacrylate (abbreviated as TRIM).
[0118] Any ratio of simple monomers to crosslinking agents can be used that provides a MIP structure of appropriate integrity, e.g., that can be used in the context of the final application (e.g., in food or feed products, in water intended for aquaculture use, in vivo, etc). Those skilled in the art can select suitable ratios of monomers to provide the desired structural integrity, which is intimately related to the nature and structure of the targeted molecule and to the nature and structure of the template used.
[0119] In embodiments, a MIP has a molar aflatoxin template to monomer ratio of about 100:1 to 1:100 (w/w). For example, ratios of aflatoxin template to monomer ratios of about 1:2 to 1:7 are utilized. In other embodiments, a MIP has a molar monomer to crosslinker ratio of about 1:4 to 1:10.
[0120] In embodiments, a MIP changes volume when contacted with a solvent. In embodiments, a MIP contacted with an aqueous solvent can adsorb up to 10 times more water than its weight. In other embodiments, an MIP is selected that, when placed in a solvent, the volume of the MIP increases about 75%, 50%, 40%, 30%, 20%, 10%, 5% or less than the volume of the MIP in a dried state. The solvent or the solvent mixture used as a medium for MIP synthesis also has an impact on the swelling properties of MIP and on the size of cavities and pores size and distribution within the tri-dimensional MIP network and the formation of micro-, meso-, macrospheres and agglomerates. In embodiments, one or more porogens may be employed in the synthesis of a MIP in order to alter the cavity size or swellability of the MIP. In certain embodiments, polar solvents such as acetonitrile are used as a solvent or co-solvent for MIP polymerization when an increase in MIP swelling and increase of MIP cavity size is desired. Alternatively, such solvents are avoided when an increase in MIP swelling and MIP cavity size is not desired (e.g., when MIP is intended for use as a chromatographic column where swelling may impede flow rate and disturb the elution of analytes and the ability of the HPLC instrument to perform). In embodiments, the swellability of the MIP is compared to a corresponding NIP.
[0121] In embodiments, the characteristics of an MIP is compared to a corresponding NIP. A corresponding NIP comprises the same crosslinked polymer as the MIP but is formed in the absence of an aflatoxin template.
[0122] In embodiments, a composition comprises a MIP and a carrier. In embodiments, the composition includes an effective amount of the MIP to sequester aflatoxin from a material. In embodiments, the effective amount is an amount that provides for the sequestering of at least 40% of the aflatoxin in the material based on weight per unit of material, and/or that reduces aflatoxin in the material to less than 0.5 parts per billion (ppb). The compositions are formulated with suitable carriers, excipients, and other agents that provide suitable transfer, delivery, stability, and functionality of the MIP.
Methods of Synthesis of MIP
[0123] In embodiments, methods of synthesis of MIPs are described. Different polymerization methods may be used including free radical, cationic, and anionic polymerization. Polymerization conditions are selected and provided herein that do not adversely affect the active conformation of the compound for which a complementary polymeric compound is to be produced. In particularly preferred embodiments, free radical precipitation polymerization methods are used.
[0124] The method of making an MIP generally comprises providing an aflatoxin template, having a Formula (I):
[0000]
[0000] wherein R 1 is selected from H, C 1-6 alkyl, substituted C 1-6 alkyl, and a halo substituted C 1-6 alkyl; R 2 is selected from halo, C 1-6 alkyl, substituted C 1-6 alkyl, a halo substituted C 1-6 alkyl, CH 2 C(O)OR′, and CH(C(O)OR′) 2 ; R′ is selected from H, C 1-6 alkyl, substituted C 1-6 alkyl, and a halo substituted C 1-6 alkyl; and R 3 is selected from H, C 1-6 alkoxy, and substituted C 1-6 alkyl; or wherein R 1 together with R 2 form a C 4-7 cycloalkyl ring, a halo substituted C 4-7 cycloalkyl ring, an oxo substituted C 4-7 cycloalkyl ring, C 4-7 cycloalkoxy ring a hydroxy substituted C 4-7 cycloalkyl ring and a carboxylic group substituted C 4-7 cycloalkyl; and R 3 is selected from H, C 1-6 alkoxy, and substituted C 1-6 alkyl; and combining the aflatoxin template with at least one monomer and one or more crosslinkers. Upon combining the monomer and crosslinker(s), the monomer and crosslinker(s) are polymerized to form a molecularly imprinted polymer intermediate.
[0125] A corresponding non-imprinted polymer (NIP) for a specific MIP is formed using the same method, same monomer, and same crosslinker as the MIP but lacks the presence of the aflatoxin template.
[0126] The disclosure also provides compositions comprising a MIP as described herein in a carrier. In embodiments, the carrier is a physiologically acceptable carrier. In other embodiments, the carrier is a solvent.
Molecularly Imprinted Polymer Intermediates
[0127] The aflatoxin template combined with a MIP precursor polymer forms a molecularly imprinted polymer intermediate. This molecularly imprinted polymer intermediate is a complex of a crosslinked MIP precursor polymer, having been made using a monomer, and an aflatoxin template. In at least one embodiment, the aflatoxin template has or comprises a Formula (I):
[0000]
[0000] wherein R 1 is selected from H, C 1-6 alkyl, substituted C 1-6 alkyl, and a halo substituted C 1-6 alkyl; R 2 is selected from halo, C 1-6 alkyl, substituted C 1-6 alkyl, a halo substituted C 1-6 alkyl, CH 2 C(O)OR′, and CH(C(O)OR) 2 ; R′ is selected from H, C 1-6 alkyl, substituted C 1-6 alkyl, and a halo substituted C 1-6 alkyl; and R 3 is selected from H, C 1-6 alkoxy, and substituted C 1-6 alkyl; or wherein R 1 together with R 2 form a C 4-7 cycloalkyl ring, a halo substituted C 4-7 cycloalkyl ring, an oxo substituted C 4-7 cycloalkyl ring, C 4-7 cycloalkoxy ring a hydroxy substituted C 4-7 cycloalkyl ring and a carboxylic group substituted C 4-7 cycloalkyl; and R 3 is selected from H, C 1-6 alkoxy, and substituted C 1-6 alkyl. In particular, the aflatoxin template analog is selected from the group consisting of 4-(2-chloroethyl)-5,7-dimethoxy coumarin and 5,7-dimethoxycyclo pentenon[2,3-c]coumarin.
[0128] In some embodiments, the aflatoxin template and at least one monomer and one or more crosslinkers is combined in one or more organic solvents. In embodiments, one or more solvents are selected from the group consisting of acetonitrile, toluene, cyclohexane, polyvinyl alcohol in water solution, and a mixture of two or more of acetonitrile, toluene, cyclohexane, polyvinyl alcohol in water solution. In a specific embodiment, a mixture of acetonitrile and toluene is used as a solvent. In particular, the solution of acetonitrile and toluene comprises at least about 20% acetonitrile.
[0129] In other related embodiments, an initiator is used to generate free radicals formed by thermal decomposition. Initiating agents include but are not limited to azo-bisisobutyronitrile (abbreviated as AIBN), azo-bisdimethylvaleronitrile (abbreviated as ABDV), dimethylacetal of benzil, benzoylperoxide (abbreviated as BPO), and 4,4′-azo(4-cyanovaleric acid). In a specific embodiment, azo(bis)-isobutyronitrile is the initiator. In embodiments, polymerization is initiated by forming free radicals in an organic solvent at a temperature between 55 and 110° C.
[0130] In embodiments, a method of synthesis further comprises adding a porogen to change the size of the cavities and the swellability of the MIP. Examples of porogens include toluene, xylene, and ethylbenzene.
[0131] The molecularly imprinted polymer intermediate can be made using an aflatoxin template compound to monomer ratio from about 100:1 to 1:100. In other embodiments an aflatoxin template compound to monomer ratio is from about 1:2 to 1:7.
[0132] The molecularly imprinted polymer intermediate can also be made using a crosslinker, and the monomer to crosslinker ratio can be from about 1:4.1 to 1:10.
[0133] Table 1 provides a series of examples of molecularly imprinted polymer (MIP) intermediates and non-imprinted polymer (NIP) intermediates and several aflatoxin template to monomer ratios and monomer to crosslinker ratios that are within the scope of the molecularly imprinted polymer intermediates described herein.
[0000]
TABLE 1
Ratios of template vs. monomer vs crosslinker for the
preparation of 6 MIPs and NIPs.
Syn-
Product
Mole Ratio
Mole Ratio
thesis
Mass
Name
Template:Monomer
Monomer:Crosslinker
Yield
(g)
MIP-001
1:2.0
1:5.7
50.2%
1.36
NIP-001
—
1:5.8
91.3%
4.93
MIP-002
1:2.3
1:9.6
76.3%
3.50
NIP-002
—
1:9.2
89.4%
4.14
MIP-003
1:4.6
1:4.1
62.1%
3.03
NIP-003
—
Not Synthesized
N/A
0.00
MIP-004
1:4.0
1:10.0
74.7%
6.22
NIP-004
—
1:10
93.4%
7.78
MIP-005
1:6.8
1:5.8
117.3%
13.54
NIP-005
—
1:5.8
98.0%
11.31
MIP-006
1:7.1
1:9.6
69.3%
7.19
NIP-006
—
1:9.4
57.7%
5.33
[0134] Once the molecularly imprinted polymer intermediate is formed, it is precipitated and the aflatoxin template is removed from the molecularly imprinted polymer intermediate to form a molecularly imprinted polymer. This process can be achieved by washing the molecularly imprinted polymer intermediate with a solvent. In embodiments, a solvent is selected that has a similar polarity and/or solubility as the aflatoxin template. In embodiments, an organic solvent is selected from the group of ethyl alcohol, methyl alcohol, acetonitrile, toluene, and a mixture of thereof. Aflatoxin template removal can be determined by known methods such as by LC-MS. Upon removal of the aflatoxin template, a molecularly imprinted polymer is formed and available to sequester an aflatoxin molecule. In embodiments, the MIP is dried.
[0135] In embodiments, yield of the MIP can be enhanced by increasing the template to monomer ratio and/or increasing the monomer to crosslinker ratio. In embodiments, the template to monomer ratio is at least 1:2 and/or the monomer to crosslinker ratio of at least 1:6.
Method of Use
[0136] The disclosure provides methods of sequestering one or more aflatoxins comprising contacting a molecularly imprinted polymer comprising a crosslinked polymer having a plurality of cavities, wherein at least some of the cavities provides for reversible binding to at least one of the aforementioned aflatoxins. Once the MIP is formed, it can be placed within or on a material suspected of containing an aflatoxin, optionally containing an aflatoxin, or known to contain an aflatoxin. It should be appreciated that the materials containing aflatoxin could be a gas, semi-gas, liquid, semi-liquid, or solid. In exemplary embodiments, the materials containing aflatoxin are selected from the group consisting of soil, a spice, a beverage, a foodstuff, an animal feed, a pharmaceutical composition, a nutraceutical composition, and a cosmetic composition. In one embodiment, the material containing aflatoxin is milk.
[0137] A select amount (e.g. effective amount, or inclusion rate) of MIP is exposed to the material containing or suspected of containing aflatoxin. In embodiments, an amount of the MIP per unit of material is at least 0.01%. For example, an MIP synthesized with a molar aflatoxin template compound to monomer ratio of at least 1:6.8, a molar monomer to crosslinker ratio of at least 1:5.8, and has an inclusion rate of at least 0.1%, adsorbs at least 76.5% of the aflatoxin M1(AFM1) from a 100 ng/L AFM1 solution in buffer. In another example, an inclusion rate of at least 1.0% showed 100% adsorption of AFM1. In other embodiments, the MIP/material ratio is at least 0.01% to 100%. In embodiments, an amount of MIP per volume of liquid is about 100 mg to 1 kilogram per liter of material.
[0138] In embodiments, a MIP is contacted with the material containing or suspected of containing aflatoxin for at least 1 second. In other embodiments, the MIP is contacted with the material containing aflatoxin or suspected of containing aflatoxin for about 1, 2, 3, 4, 5 minutes or more. In other embodiments, the MIP is contacted with the material from about 1 second to 500 minutes.
[0139] In embodiments, the material and the MIP are contacted in a solution with a pH of 1-13. In other embodiments, the pH is about pH 6.0, pH 7.0, pH 7.5, or less.
[0140] In embodiments, the MIP is contacted with the material in batch with or without agitation. In other embodiments, an MIP is placed in a chromatography column, such as solid phase extraction column.
[0141] Once the MIP is in contact with the material for a predetermined period of time, the MIP, which now contains sequestered aflatoxin, is separated from the material. One such separation method is filtration. Another separation method is centrifugation.
[0142] Adsorption of the aflatoxin by the MIP ranges from at least 10%, 20%, 30, or 40% or greater of the weight of an aflatoxin per unit of material. Adsorption obtained from a material is specific to the conditions used in terms of pH, temperature, concentration of toxin, nature of MIP, agitation, and flow of the material. If time of exposure of the MIP to the mycotoxin is increased and/or the inclusion rate is increased, then a 100% adsorption is observed. Adsorption is affected by time of exposure, concentration of aflatoxin, inclusion level of the MIP, and environment. When the material is exposed to the MIP for at least 5 minutes, with an inclusion rate of at least 0.1%, the MIP can sequester at least 40% by weight of the aflatoxin in the material. In related embodiments, the MIP will sequester a sufficient amount of aflatoxin from the material to reduce the amount of aflatoxin in the material to less than 0.5 or less than 0.05 parts per billion.
[0143] In some embodiments, the material can be contacted with a MIP for multiple exposures until aflatoxin levels are reduced. For example, a first exposure of the material to a MIP can remove about 10% or more of the aflatoxin. The MIP with bound aflatoxin is then removed and washed and reused or MIP with little or no bound aflatoxin is then contacted with the material again. Multiple exposures can continue until the amount of aflatoxin is reduced for example, to less than 0.5 ppb.
[0144] Optionally, after separation of MIP with bound aflatoxin, aflatoxin can be removed from the MIP by treating with a solvent that can disrupt the chemical association of the aflatoxin with the MIP. However, there is a balance between affinity of the MIP for binding of the aflatoxin and the amount of bound aflatoxin that can be removed. In embodiments, for a MIP with high affinity for aflatoxin, the MIP releases about 25%, 20%, 15%, 10%, 5%, 1% or less of the aflatoxin sequestered from the material in the presence of a solvent, for example, as compared to a corresponding NIP. In certain embodiments, it is desirable to reuse a MIP from which aflatoxin previously sequestered has been removed beforehand according to suitable and sufficient amount of organic solvent washes so that no detectable amount of aflatoxin can be found leaching from the MIP material using conventional LC-UV or LC-fluorescence, or LC-MS quantitative methodologies.
[0145] Another optional step in the process of using MIPs for the sequestering of aflatoxin, is to detect the amount of aflatoxin (i.e. parts per billion (ppb)) in a material prior to treatment with an MIP. Additionally, the material may be again tested, during and/or after treatment with an MIP to determine sequester rate of the aflatoxin. Furthermore, the amount of MIP required to sequester a pre-determined concentration of aflatoxin may also be elucidated, depending on the particular MIP utilized. Moreover, the MIP complexed with aflatoxin, once separated from the material, may be tested for aflatoxin concentration sequestered.
[0146] Quantitative adsorption efficacy can be determined by using UPLC-Xevo-TQD MS/MS (Waters Corp.). For example, a gradient of water/0.1% formic acid (v/v) and methanol/0.1% methanol (v/v) is used and analytes can be separated on an Acquity UPLC® BEH C18 1.7 μm 2.1×50 mm column (Waters. Corp.). The method is optimized for the analysis of AFM1/AFB1/aflatoxin template in buffer and milk using a C13-AFB1 isotopic dilution and normalization technique.
EXAMPLES
Synthesis of Aflatoxin M1 Template Molecules
Example 1
Preparation of 4-(2-chloroethyl)-5,7-dimethoxycoumarin (AFM-Template-1)
[0147] Cold solution of ethyl-4-chloroacetoacetate (26.6 gr) in acetic acid (12.5 ml), and concentrated sulfuric acid (6.25 ml) was added drop-wise for 15 minutes to a solution of 3,5-dimethoxyphenol (25.0 gr) in acetic acid (50.0 ml) at 8-10° C. under nitrogen atmosphere. The reaction mixture was consecutively stirred at 20-25° C. for 1 hour, slowly heated to 60° C. and stirred for 12 hours at 55-60° C. The reaction mixture was cooled to 40° C. and hot water (150.0 ml) was added drop-wise over a period of 30 minutes at 40-45° C. The mixture was cooled to room temperature and stirred for 1 hour to precipitate the product. The product was filtered, washed with water (2×25 ml) and dried under suction for 30 minutes. Cold methanol (50.0 ml) was added to the crude product and the slurry was stirred at 8-10° C. for 30 minutes. The product was filtered and washed with cold methanol (2×25 ml) and dried under vacuum to obtain the final product, 4-(2-chloroethyl)-5,7-dimethoxycoumarin (AFM-Template-1), which had the appearance of a white fluffy powder (39 gr). The resulting product was carried forth and used in the next step as is.
Example 2
Preparation of 4-(2,2-dicarboethoxy-ethyl)-5,7-dimethoxycoumarin (AFM-Intermediate-1)
[0148] Diethylmalonate (32.75 gr) was added to a mixture of 4-(2-chloroethyl)-5,7-dimethoxycoumarin (AFM-Template-1, 40.0 gr), 18-Crown-6 (4.96 gr), and potassium iodide (3.12 gr) in acetonitrile (400 ml) at room temperature under nitrogen atmosphere. Potassium-t-butoxide (t-BuOK, 22.8 gr) was added in one lot to the reaction mixture (slightly exothermic) at room temperature. The temperature of the reaction mixture (suspension) was slowly increased to 40° C., and then stirred for 24 hours at 35-40° C. under nitrogen atmosphere. The reaction mixture was cooled to room temperature and evaporated to dryness under vacuum at 35-40° C. to produce a yellow semi-solid residue. The residue was dissolved in a mixture of water (200 ml) and ethylacetate (400 ml) under stirring. The pH of the mixture was adjusted to 5 with diluted hydrochloric acid. The organic layer was separated from the aqueous layer, this latter being further extracted with ethylacetate (2×200 ml). Organic layer dried over anhydrous sodium sulfate (100 gr) were combined and filtered. The filtrate was concentrated to dryness under vacuum at 35-40° C. to give the 4-(2,2-dicarboethoxy-ethyl)-5,7-dimethoxycoumarin (AFM-Intermediate-1), which had the appearance of a yellow solid (58 gr). The resulting product was carried forth and used in the next step as is.
Example 3
Preparation of Diacid (AFM-Intermediate-2)
[0149] Sodium hydroxide pellets (15.6 g) were added to a suspension of 4-(2,2-dicarboethoxy-ethyl)-5,7-dimethoxycoumarin (AFM-Intermediate-1, 58.0 g) in ethyl alcohol (290 ml) at room temperature. The temperature of the reaction mixture (suspension) was slowly increased to 60° C., and then stirred for 3 hours at 60-65° C. The reaction mixture was cooled to room temperature and then pH of the mixture adjusted to 2 with concentrated hydrochloric acid to precipitate the product. The slurry was cooled to a temperature of 10° C. and stirred for 1 hour at 8-10° C. to complete precipitation of the product. The product was filtered (Crop-1), and then ethanol distilled-off from the mother liquor by distilling at 20-25° C. under vacuum, and then the concentrated mass was cooled to 10° C. to precipitate the product, filtered the same (Crop-2). The combined product was washed with 1:1 (v/v) mixture of methanol and water (2×200 ml) and then further dried under vacuum to obtain the diacid (AFM-Intermediate-2), which had the appearance of a yellow solid (45 g). The resulting product was carried forth and used in the next step as is.
Example 4
Preparation of Monoacid (AFM-Intermediate-3)
[0150] The diacid (AFM-Intermediate-2, 30 g) was suspended in m-xylene (300 ml) at room temperature. The temperature of the reaction mixture (suspension) was slowly increased to 135° C., and then stirred for 12 hours at 135-140° C. The reaction mixture was cooled down to room temperature and then the formed precipitated filtered. The precipitate was washed with n-Hexanes (2×100 ml) and dried under vacuum to obtain the monoacid (AFM-Intermediate-3), which appeared as half-white solid (25 g). The resulting product was carried forth and used in the next step as is.
Example 5
Preparation of 5,7-dimethoxycyclo pentenon[2,3-c]coumarin (AFM-Template-2)
[0151] The monoacid (AFM-Intermediate-3, 4.75 g) was suspended in polyphosphoric acid (9.50 gr) at room temperature under nitrogen atmosphere. The temperature of the reaction mixture (suspension) was slowly increased to 75° C., and then stirred for 12 hours at 70-75° C. The reaction mixture was cooled to room temperature and then water (50 ml) was added slowly to decompose the excess polyphosphoric acid and the reaction mixture was stirred for 1 hour at room temperature. Dichloromethane (50 ml) was added to the reaction mixture and stirred for 15 minutes, organic layer was separated. The product was extracted with dichloromethane (2×25 ml). The combined organic layer was dried over anhydrous sodium sulfate (25 g) and concentrated to dryness by distillation under vacuum. The residue was suspended in methanol and stirred for 30 minutes at room temperature. The product was filtered and washed with methanol (2×10 ml) and then dried under vacuum to obtain 5,7-dimethoxycyclo pentenon[2,3-c]coumarin (AFM-Template-2), which appeared as half-white solid (2.5 g).
Example 6
Produced MIP Composition and Characteristics
[0152] Experiments were conducted during development of embodiments of the disclosure to test MIP polymers under their free flowing powder form for their adsorption properties toward AFM1 (Biopure, Romer Labs® Inc, Union, Mo.) mycotoxin and for the removal of the AFM1 mycotoxin from liquid or semi-liquid media via chemical interactions. The MIP produced was used herein to depict the differences in affinity of sequestration of the AFM1 mycotoxin and to evaluate the specificity of the material.
[0153] Six independent MIPs were prepared using AFT-1 (1.0 mmol, template), methacrylic acid (2.0 mmol, MAA, monomer), and ethylene glycol dimethacrylate (5.0 mmol, EGDMA, cross-linker) in a mixture of acetonitrile and toluene (1:3 v/v) at room temperature under nitrogen atmosphere by using different molar ratio of AFT-1 vs. MAA and monomer vs. cross-linker (Table 1). The solution was stirred for 1 h at RT under inert atmosphere. Then, the azo(bis)-isobutyronitrile (0.01 mmol, AIBN, initiator) was added and slowly heated and maintained for 30 min at 60-65° C. to precipitate the MIP microspheres. Two independent Non-Imprinted Polymers (NIP's) were also prepared through the same procedure but in the absence of AFT-1. The template (AFT-1) was removed from the MIP by continuous washing with toluene until complete disappearance of template in the washings as determined by the analysis of eluent through LC-UV, LC-fluorescence.
[0154] The resulting MIP and NIP polymeric material was synthesized as a block polymer which was ground to a powder with a mortar and pestle. The NIP polymeric material was white in color and when ground to a powder was highly electrostatic. The MIP polymeric materials were brown in color due to the presence of the brown colored template with the exception of MIP-005 which was red in color (a different synthesis batch template was used for this MIP which was red in color). Minimal color change was experienced during the toluene rinses of the MIP products. However when washed with methanol, the color of the powder was extremely muted and less dark as the colored template was rinsed from the polymer structure. The MIP polymeric materials in the powder form were also somewhat electrostatic, although not to the degree of the NIP products.
[0155] Swelling properties of powder forms of MIP/NIP were investigated (Table 2). We concluded that the swelling properties of MIP were considerably higher than NIPs. MIP-001 exhibited the greatest volume increase by swelling to 240% of its original size in buffer. MIP-002 also showed significant size increase to 200% of its original size. MIP-005 and NIP-005 were the only polymeric materials which showed no size increase when exposed to buffer for an extended period of time while NIP-004 showed a minimal 11% volume increase. The remaining MIP products all exhibited a moderate degree of volume increase due to swelling, to 150-167% of their original size.
[0000]
TABLE 1
Ration of template vs. monomer vs cross linker for the preparation
of 6 MIPs and NIPs.
Syn-
Product
Mole Ratio
Mole Ratio
thesis
Mass
Name
Template:Monomer
Monomer:Crosslinker
Yield
(g)
MIP-001
1:2.0
1:5.7
50.2%
1.36
NIP-001
—
1:5.8
91.3%
4.93
MIP-002
1:2.3
1:9.6
76.3%
3.50
NIP-002
—
1:9.2
89.4%
4.14
MIP-003
1:4.6
1:4.1
62.1%
3.03
NIP-003
—
Not Synthesized
N/A
0.00
MIP-004
1:4.0
1:10.0
74.7%
6.22
NIP-004
—
1:10
93.4%
7.78
MIP-005
1:6.8
1:5.8
117.3%
13.54
NIP-005
—
1:5.8
98.0%
11.31
MIP-006
1:7.1
1:9.6
69.3%
7.19
NIP-006
—
1:9.4
57.7%
5.33
[0000]
TABLE 2
Percent volume expansion of each MIP/NIP powder after 90 h
exposure to pH 6.0 ammonium acetate buffer solution in NMR tubes.
Product
Percent Volume Increase
MIP-001
140%
MIP-002
100%
MIP-003
67%
MIP-004
50%
MIP-005
0%
MIP-006
67%
NIP-004
11%
NIP-005
0%
Example 7
Produced MIP Sequestration Capabilities Toward Mycotoxins—Applied to AFM1 in Buffer
[0156] Quantitative adsorption efficacy was carried out using UPLC-Xevo-TQD MS/MS (a.k.a., UPLC-MS/MS) (Waters Corp.). A gradient of water/0.1% formic acid (v/v) and methanol/0.1% methanol (v/v) was used and analytes were separated on an Acquity UPLC® BEH C18 1.7 μm 2.1×50 mm column (Waters. Corp.). The method was optimized for the analysis of AFM1/AFB1/AFT-1 in buffer and milk using a C13-AFB1 isotopic dilution and normalization technique.
Instant Trapping Properties
[0157] Experiments were conducted during development of embodiments of the disclosure to test for the inclusion rate of the MIP/NIP investigated by ramping said levels of inclusion from 0.001 to 1.0% (w/v) of material in a pH 6.0 environment. Several instant trapping studies were done to ascertain the viability of using MIP products to adsorb AFM1. To perform this study, 0.01 mg, 0.1 mg, 1.0 mg, and 10.0 mg of MIP-005 were loaded into extraction cartridges with polytetrafluoroethylene (PTFE) frits using a slurry technique in buffer for the lowest inclusion rates. Briefly, MIP was put in suspension using buffer and loaded onto the cartridge and weighted to determine the precise amount of the MIP. The quantities of MIP used in this experiment represent inclusion rates of 0.001%, 0.01%, 0.1%, and 1.0% (w/v). This experiment was performed at room temperature.
[0158] The polymeric material was “primed” by adding and subsequently eluting 1 volume (1 mL) of water, 1 of methanol, and 2 of buffer in succession. One milliliter of a solution of buffer spiked with 100 ng/L of AFM1 was then added to each cartridge and followed after 1 min by 1 mL of buffer with no AFM1. These final two elutions were collected in the same silanized UPLC vial for analysis of AFM1 content. A volume of 1 mL of methanol was added to the cartridges for the elution of trapped AFM1 and the eluent was collected followed by 1 mL of toluene eluent which was likewise collected separately for analysis. Methanol and toluene eluent samples were dried using nitrogen gas and reconstituted in 1 mL of buffer before analysis. To allow for effective quantification of results using the UPLC-MS/MS, standards were created of known concentrations of AFM1 in buffer at 1, 5, 10, 50, and 100 ng/L.
[0159] Results showed that 1 mg/L of free flowing polymer was sufficient for the adsorption of 76.5% toward 100 ng/L of AFM1, which was selected as potential aflatoxin target. FIG. 1 . This inclusion rate was used as a reference for the rest of the MIP evaluation. Instant sorption of 100 ng/L of AFM1 by MIP and NIP packed into solid-phase extraction (SPE) cartridges and eluted with a 100% methanol solution was investigated. We found that the adsorption varied between 75.2 and 94.4 ng/L of AFM1 adsorbed.
[0160] The quantity of AFM1 present in the methanol and toluene extraction rinses serves as an indicator of the strength with which the AFM1 is being held by the MIP/NIP. We are demonstrating that each product tested released between 31.1 and 44.4 ng/L of AFM1 when washed with 100% methanol with two exceptions. MIP-001 released 64.3 ng/L of AFM1 and MIP-005 released a low 22.6 ng/L of AFM1. However, with the exception of these two products, each of the MIPs and NIPs exhibited a similar degree of interaction strength with the AFM1. Little to no AFM1 was found in the toluene rinses for each of the MIP/NIP products. This is likely due to the fact that much of the AFM1 was released in the methanol extraction and also that the nonpolar nature of toluene had little effect on desorption of the polar AFM1. See FIG. 1 .
Kinetic of Adsorption
[0161] Experiments were conducted during development of embodiments of the disclosure to test the time of reaction and its effect on the adsorption using free flowing MIP/NIP reacted under 225 rpm orbital shaking at pH 6.0 over 6 periods of time, from 5 to 500 minutes with a 90 ng/L AFM1 10 mL solution. Adsorption efficacy was measured by quantitation of the mycotoxin remaining in the supernatant and eluting from the MIP/NIP after methanol wash, which defined adsorption efficacy and selectivity. Due to the fact that there is instant adsorption, the AFM1 adsorption quantities for each time point (15, 30, 60, 90 minutes and 18 hrs) were averaged for each product. All test tubes were then centrifuged for 10 minutes at 3,000 rpm and a transferred into UPLC vial for analysis. The powder (MIP or NIP) was then transferred to a 2 mL Eppendorf tube where 1 mL of methanol was added and vortexed for approximately three seconds. Each tube was then centrifuged for 5 minutes at 10,000 rpm and 500 μL of liquid was removed and placed in a UPLC vial. The samples were then dried using nitrogen and reconstituted in 500 μL of buffer before analysis by means of a UPLC-MS/MS system.
[0162] All polymers at every time point were able to adsorb between 45 and 55% of AFM1 and non-significant differences were observed between MIP and NIP. See FIG. 2 . Selectivity was however vastly different between MIP and NIP. MIPs depending on their formulation were only partially releasing AFM1. The differences observed in terms of release of the targeted molecule following methanol wash with the previous experiment, clearly demonstrated that the increase of the time of reaction between target molecule and MIP increased the stability of the sequestering, whereas NIP showed a lower stability of interaction resulting in the release of more of the targeted compound in the methanol wash. This experiment established the clear specificity of the interaction and adsorption quality of the MIP toward aflatoxin M1. Further investigation demonstrated that when different concentration of AFM1 were tested varying from 45 to 450 ng/mL, MIP/NIP exhibited similar adsorption capacity around 50%, accounting for a chemical equilibrium between adsorbed vs. non-adsorbed AFM1 present in the environment.
Example 8
Produced MIP Sequestration Capabilities Toward Mycotoxins—Applied to AFM1 in Milk
[0163] Experiments were conducted during development of embodiments of the invention to test the MIP (MIP-003 for its capacity at interacting with 225 ng/L AFM1 in raw milk. A slurry of MIP-003 in LC-MS grade water was used to place 0.1 mg, 1.0 mg, and 10.0 mg of powder in respective silanized test tubes (1 mL of water from the slurry in each test tube). 1 mL of water was placed in two additional test tubes with no powder to serve as controls in the form of both spiked and blank raw milk. 9 mL of raw milk spiked to 250 ng/L AFM1 was then placed in each test tube, except for the blank milk control which received 9 mL of milk which was not spiked. All test tubes were then placed on an orbital shaker set to 200 rpm for one hour at room temperature following which the test tubes were centrifuged at 4,000 rpm for 10 minutes. Fourteen 100 mg C18 SPE cartridges (triplicate for each spiked milk sample and duplicate for the blank milk) were activated by eluting 1 mL of methanol and 1 mL of water in succession using vacuum pressure. After centrifugation, 1 mL of liquid was placed in each respective SPE cartridge and each sample, with the exception of the blank milk, was spiked with 10 μL of a 100 ppb sample of AFB1 in acetonitrile to serve as an internal standard. The liquids were then eluted using vacuum pressure followed by the elution of 1 mL of water through each cartridge. Following this, 1 mL of methanol was placed in each cartridge and eluted into a silanized UPLC vial using positive pressure. After elution, one of the two blank milk samples was spiked to 225 ng/L AFM1 and with 10 μL of the 100 ppb AFB1 internal standard solution. To allow for quantification of results, standards of 1, 5, 10, 25, 50, 100, 250, and 500 ng/L AFM1 concentration were created in acetonitrile. One milliliter of each sample was dried by blowing nitrogen over it and reconstituted in 1 mL of buffer. A volume of 500 μL of each standard was then spiked with 5 μL of the 100 ppb AFB1 solution to allow for the creation of a calibration curve.
[0164] At an inclusion rate of 0.1% (w/v), the MIP was able to remove 45.3% of the toxin. As seen in FIG. 3 , we established that even 0.1 mg (0.001% inclusion rate) and 1.0 mg (0.01%) of free flowing powder also exhibited adsorption in the range of 6.7% and 15.4% of AFM1 removed from milk, respectively. This experiment clearly defined the applicability of MIP at targeting specifically AFM1 in a complex raw milk matrix even at inclusion rates as small as 0.001%.
Example 9
[0165] An initial study evaluated the level of inclusion of MIP necessary to sequester AFM1. MIP-005 material was studied in buffer conditions. As shown in the FIG. 5 , it was found that 1 mg of powder (representing an inclusion rate of 0.1%, w/v) was able to adsorb 76.5% of the AFM1 from the 100 ng/L AFM1 solution in buffer. Meanwhile the 0.001% and 0.01% (w/v) inclusion rates resulted in negligible AFM1 adsorption. On the other hand, an inclusion rate of 1.0% (w/v) showed 100% adsorption of AFM1. See FIG. 5 .
[0166] All publications and patents described herein are hereby incorporated by reference.
[0167] Those skilled in the art will readily appreciate that many modifications are possible without materially departing from the novel teachings and advantages of this disclosure. Accordingly, all such modifications are intended to be included within the scope of this disclosure as defined in the following claims. | Molecularly imprinted polymers (MIPs) are materials exhibiting molecular recognition of a target molecule. MIPs are synthesized in the presence of an aflatoxin template, a mimic to the targeted molecule, used as an imprint that is further washed away with suitable solvent after completion of the polymerization process, leaving a cavity in the polymer of the same stereochemistry, functionality and morphology to the template. When the MIP encounters an aflatoxin, the molecule is bound in the cavity with a receptor-like affinity. | 2 |
This is a division, of application Ser. No. 272,859, filed July 18, 1972, now U.S. Pat. No. 3,844,875, issued Oct. 29, 1974.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention is directed to a ceiling board and, more particularly, to a perforated ceiling board with a vinyl facing.
2. Description of the Prior Art
Typical of the standard fiber composition ceiling boards is that shown in U.S. Pat. No. 2,791,289, which issued to D. A. Proudfoot et al. This patent shows a fiberboard ceiling product which has been provided with perforations 11 due to the use of pin punches 12. These ceiling boards are made from either vegetable fiber or mineral wool fiber, and are laid up in mat form by several different techniques.
U.S. Pat. No. 3,437,551 discloses a polyurethane panel which has a thermoplastic film adhered thereto. This patent teaches that a plug of material must be removed from a laminate structure of vinyl and foam or else the foam would close up any perforation which is made by a punch which merely pierced the foam. With vegetable fiber and mineral wool fiberboards, there is usually no condition involving the closing up of a perforation made by a punch such as you would encounter with a foam material.
The invention herein is in the utilization of a base of a conventional fiber material which holds its shape once it is perforated, but providing an overlaying structure of a plasticized material which will tend to grow and form a smaller hole after a punch has been withdrawn from the composite structure. Consequently, a unique design effect is formed without any loss of sound-absorbing qualities.
SUMMARY OF THE INVENTION
The invention relates to a method for producing a uniquely perforated acoustical ceiling product, wherein pin holes close considerably after punching to produce smaller concave holes quite unlike the regular square edge perforations normally found in acoustical products.
The effect is achieved by laminating a plasticized or higher than normal plasticizer containing vinyl film to the surface of a standard fiber composition ceiling board. The film is perforated in the usual manner using various size pins. Immediately after withdrawal of the pins, the holes in the vinyl film slowly begin to close. The final opening in the vinyl film is approximately 25% of the original hole size, and this original hole size is still maintained within the underlying standard fiber composition ceiling board. The closing action of the vinyl film causes the surface of the film at the hole to become concave or dish-shaped, thus producing a unique design effect. In addition, no reduction in NRC is observed due to the fact that the hole in the board is still full size.
The resultant product is a highly scrubbable, damage-resistant, acoustical ceiling product with uniquely designed perforations having considerably smaller hole size than the underlying ceiling board hole size.
BRIEF DESCRIPTION OF THE DRAWING
FIG. I is a showing of a fiber composition ceiling board with the vinyl covering retaining its hole size; and
FIG. II is a showing of a conventional fiber composition ceiling board which has been provided with a plasticized vinyl film coating.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Fiber ceiling boards such as that shown in FIG. I are conventional in the art. The boards are normally formed about 3/4 inch thick from either vegetable fiber or mineral fiber materials. After the board has been formed by conventional water-laid techniques, it is dried and then perforations are provided in the board. The primary purpose of the perforations is to increase the sound-absorbing ability of the ceiling board. Basically, the perforations permit a ceiling board to absorb more sound than the board would be capable of absorbing if it simply had a plain flat surface. A standard rating system is provided for the purpose of measuring the sound-absorbing ability of the board, and this is generally referred to as the NRC rating of the board.
In FIG. I, the standard fiber composition board 1 is provided with a vinyl film 3. If this vinyl film was unplasticized and was punched, the film would assume and hold the shape shown in the Figure. There would be the square edge hole configuration and the hole in the vinyl would not shrink in size.
Herein, as shown in FIG. II, the perforated acoustical ceiling product 2 is formed of a two-part laminate structure. The base structure is the standard fiber composition ceiling board 4 which has placed on the face thereof a plasticized vinyl film 6. The vinyl film is normally made about 0.015 inch thick and is normally stretched across the ceiling board and edge bonded to the edge of the ceiling board.
The composite product is then provided with perforations which are normally formed by pins in the die of a punch press. The pins are normally 0.050 inch and 0.100 inch in diameter and penetrate beyond the halfway point into the fiber composition board 4. The pin punch will pierce the vinyl layer 6 and penetrate down into the fiber composition board. Normally, the pin will tear some of the fibers in the board structure, but generally the pin simply pushes the fibers downward into the hole 8 and sideways toward the side of the hole 8. The fibers are thus compressed along the side walls and the base of the hole. Removal of the pin from the fiberboard will result in a very minor amount of spring-back of the fibers to slightly reduce the size of the hole in the fiberboard. However, generally speaking, the perforation or hole 8 within the standard fiber composition board is basically that of the size of the pin which made the perforation. The perforation 10 in the vinyl layer 6 is also initially about the same size as the size of the pin making the hole.
If the vinyl film was an unplasticized vinyl film, the hole size in the vinyl film would remain the same as it was when the pin is removed from the total ceiling product as shown in FIG. I. Consequently, the product will end up having a hole in the vinyl and a hole in the fiber composition ceiling board, both being approximately the same size and both being equal in size roughly to that of the pin making the perforation. However, if the vinyl film is made from a highly plasticized vinyl material and allowed to age, the vinyl film hole will slowly begin to close and will continue closing for approximately 24 hours. The final opening in the vinyl film is approximately 25% of the original hole size formed by the punching pin. During the closing action of the vinyl film, the film tends to dish around the hole cavity. This then causes the surface around the edge of the hole in the vinyl film to become concave or dish-shaped, thus producing a unique design effect in the finished product. Even though the board hole size has had its entrance reduced by the vinyl film, there is no reduction in the NRC over that which would exist if the board were measured without the vinyl film closing over a portion of the opening of the perforation 8 in the fiber composition ceiling board. Consequently, you end up with what appears as a smaller size perforation in the board, as seen from the exterior of the board, but you actually secure an NRC rating which is equal to the size of the perforation within the fiber composition ceiling board, which is naturally larger.
Listed below are several examples of vinyl formulations which were utilized and the results obtained therefrom:Formulation: Parts by Weight______________________________________ No.1 No.2 No.3Polyvinyl Chloride Resin, Firestone FPC 9282, molecular weight -- 60,000 100 100 100Chlorinated Polyethylene Impact Modifier, Dow CPE 3614 10 10 10Tricresyl Phosphate Plasticizer, Monsanto TCP 20 -- --Chlorinated Paraffin Plasticizer, ICI Cereclor S-52 10 20 --TiO 2 Pigment 2 2 2Calcium Carbonate Filler 20 20 10Organotin Mercaptide, Cincinnati Milacron TM-180 2 2 2Stearic Acid Lubricant 1 1 1______________________________________
Formulation No. 1 will produce the greatest hole size reduction (25% of original) and most noticeable dish-shape design effect. Formulation No. 2 produced a moderate dish-shape effect. Formulation No. 3 produced no dish-shape effect or hole size reduction. While the theory is not fully understood, it is believed that the plasticizer lowers the modulus of the vinyl film, thereby allowing the film to stretch around the pin during perforation. The elastic memory of the vinyl then causes the film to slowly recover to its original shape, thereby pulling the film away from the sides of the hole and producing the dish-shaped effect and hole size reduction. By plasticized vinyl film is meant a vinyl film material which contains a higher than ordinary level of plasticizer so that the the film is stretchable and will return to its original unstretched size.
The degree of closing is dependent upon the vinyl film composition, especially the plasticizer level, the film thickness and the original hole size. The primary controlling feature is the plasticizer level, it being recognized that as the film thickness increases, the less there will be a tendency for the hole size to reduce. Obviously, the greater the hole, the less the percentage of closing of the hole. The resultant product formed as above is a highly scrubbable, damage-resistant acoustical ceiling product which has a uniquely designed perforation providing considerably smaller hole openings visible on the outside of the board relative to the actual hole size in the board body. | A standard fiber composition ceiling board is provided with an outer laminate of plasticized vinyl film. The holes in the film are smaller than the holes in the fiber composition ceiling board. The product is made by laminating the vinyl film to the ceiling board, then perforating the film and the ceiling board with pin punches. The perforations in the board stay at the size at which they are formed, while the holes in the film shrink in size. | 4 |
This is a continuation of International PCT Application Numbers PCT/IB00/00074 and PCT/IB00/00076, filed on Jan. 26, 2000.
Extractive distillation is a process to separate close-boiling compounds from each other by introducing a selectively-acting third component, the extractive distillation solvent, with the result that the relative volatility of the mixture to be separated is increased and azeotropes, if present, are overcome. The extractive distillation solvent Is to be selected such that it does not form an undesired azeotrope with any of the compounds in the mixture. The invention suggests a method of separation of ethanol and ethyl acetate, and ethanol and water by distilling a mixture of the components by way of an extractive distillation process in the presence of an extractive distillation solvent.
Separation of components from ethanol mixtures thereof by extractive distillation.
FIELD OF INVENTION
The present invention relates to the separation of components from ethanol mixtures thereof by extractive distillation.
BACKGROUND TO INVENTION
Extractive distillation is a process to separate close-boiling compounds from each other by introducing a selectively-acting third component, the extractive distillation solvent, with the result that the relative volatility of the mixture to be separated is increased and azeotropes, if present, are overcome. The extractive distillation solvent is to be selected such that it does not form an undesired azeotrope with any of the compounds in the mixture.
The separation of ethanol and ethyl acetate is complicated due to the existence of an azeotrope. Trimethylbenzene has been proposed in the literature as extractive distillation solvents to produce ethanol as distillate.
The separation of ethanol and water is complicated due to the existence of an azeotrope. Azeotropic distillation using benzene or cyclohexane is commonly used to effect the separation. Membrane separation, such as pervaporation, may alternatively be used to break the azeotrope. Pressure swing distillation is another separation method that may be used to produce pure ethanol and pure water. All of these methods utilize two distillation columns. In the case of azeotropic distillation, a phase separation device is needed. In the case of membrane separation, membrane modules are needed. Extractive distillation can also be used to effect the desired separation. This method also uses a two column system but the operation is simple. Ethylene glycol has been proposed in the literature as an extractive distillation solvent for the system ethanol/water.
As has been stated in U.S. Pat. No. 5,800,681 (Berg) extractive distillation is the method of separating close boiling compounds from each other by carrying out the distillation in a multiplate rectification column in the presence of an added liquid or liquid mixture, said liquid(s) having a boiling point higher than the compounds being separated. The extractive distillation solvent is introduced near the top of the column and flows downward until it reaches the stillpot or reboiler. Its presence on each plate of the rectification column alters the relative volatility of the close boiling compounds in a direction to make the separation on each plate greater and thus require either fewer plates to effect the same separation or make possible a greater degree of separation with the same number of plates. The extractive distillation solvent should boil higher than any of the close boiling liquids being separated and not form minimum azeotropes with them. Usually the extractive distillation solvent is Introduced a few plates from the top of the column to ensure that none of the extractive distillation solvent is carried over with the lowest boiling component.
It is an object of this invention to suggest at least one further extractive distillation solvent for the separation of components from ethanol mixtures thereof.
SUMMARY OF INVENTION
According to the invention, a method of separation of ethanol from a mixture of ethanol and another compound selected from a first group consisting of ethyl acetate and water, includes the step of distilling the mixture containing at least ethanol and another compound selected from a first group consisting of ethyl acetate and water by way of an extractive distillation process in the presence of an extractive distillation solvent selected from a second group consisting of an amine, an alkylated thiopene, a paraffin and a chlorinated carbon.
The mixture may contain ethanol and ethyl acetate and the extractive distillation solvent may be selected from the group consisting of an amine, an alkylated thiopene and a paraffin.
The ethanol and ethyl acetate mixture may contain only ethanol and ethyl acetate.
The amine may be selected from a group consisting of N,N′-dimethyl-1, 3-propanediamine, N-N′-dimethylethylenediamine, diethylene triamine, hexamethylene diamine and 1,3-diaminopentane.
The alkylated thiopene may be ethyl thiopene.
The paraffin may be at least one of the components selected from the group consisting of dodecane, tridecane and tetradecane.
The mixture may contain ethanol and water and the extractive distillation solvent may be selected from the group consisting of an amine and a chlorinated hydrocarbon.
The ethanol and water mixture may contain only ethanol and water.
The amine may be selected from a group consisting of diaminobutane, 1,3-diaminopentane and diethylene triamine.
The chlorinated hydrocarbon may be hexachlorobutadiene.
BRIEF DESCRIPTION OF DRAWING
The invention will now be described by way of example with reference to the accompanying schematic drawing.
In the drawing there is shown a schematic view of an experimental apparatus for testing an extractive distillation solvent for separating components from mixtures thereof in accordance with the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
In the drawing there is shown a vapour-liquid equilibrium still 10 Including a bulb flask 12 having a tube 14 leading to a condenser 16 and terminating in an outlet 18 . The outlet 18 has an electromagnetic closure mechanism 20 .
A liquid phase sample conduit 22 leads into the flask 12 .
A further liquid phase sample conduit 24 leads into the tube 14 .
A first thermometer 26 is adapted to read the temperature of the liquid contained in the flask 12 , and a second thermometer 28 is adapted to read the temperature of the vapour in the tube 14 .
The flask 12 can be heated by a heating mantle 30 .
The extractive distillation procedure is as follows:
A liquid mixture is prepared consisting of the components to be separated and, an extractive distillation solvent. The liquid is introduced into the bulb flask 12 via conduit 22 .
The mixture in the bulb flask 12 is then heated by the heating mantle 30 and kept at boiling point.
During boiling the mixture separates into a liquid phase remaining in the bulb flask 12 and a vapour phase in the tube 14 . In the tube 14 the vapour phase is cooled by the condenser 16 , whereafter it condenses and returns as liquid to the bulb flask 12 .
The mixture is boiled and condensed for several hours, normally 5 to 6 hours. The process of evaporation and condensation is repeated until equilibrium is reached between the vapour and liquid phases. Thereafter, a liquid sample of the liquid phase in the bulb flask 12 is extracted through conduit 22 and a liquid sample of the condensed vapour phase in the tube 14 Is extracted through conduit 24 .
The temperature of the liquid phase in the bulb flask 12 is continuously monitored by the thermometer 26 , and the temperature of the vapour phase in the tube 14 is continuously monitored by the thermometer 28 .
Experiment 1
An ethanol/ethyl acetate mixture with a molar ratio of 1:1 has a relative volatility of 0.92.
The separation was effected by using a suitable amine as an extractive distillation solvent.
A mixture of ethanol (16.8 g), ethyl acetate (31.2 g) and di-ethylene-triamine (289.8 g) was charged into the flask 12 of the vapour-liquid equilibrium still 10 and the above procedure was applied. The liquid and vapour phases were analysed. The liquid and vapour molar fractions were determined to be as follows:
TABLE 1
Liquid (mole
Vapour (mole
Component
fraction)
fraction)
Ethanol
0.103
0.725
Ethyl Acetate
0.100
0.275
Di-ethylene-triamine
0.797
0.000
This translates to a relative volatility of 2.56 for the system ethanol/ethyl acetate in the ternary system shown above, the ethanol being the distillate.
Experiment 2
An ethanol/ethyl acetate mixture with a molar ratio of 0.7:1 has a relative volatility of 1.05.
The separation was effected by using a suitable substituted thiophene as an extractive distillation solvent. A mixture of ethanol (2.3 g), ethyl acetate (6.0 g) and ethyl thiophene (24.7 g) was charged into the flask 12 of the vapour-liquid equilibrium 10 and the above procedure was applied. The liquid and vapour phases were analysed. The liquid and vapour molar fractions were determined to be as follows:
TABLE 2
Liquid (mole
Vapour (mole
Component
fraction)
fraction)
Ethanol
0.148
0.690
Ethyl Acetate
0.202
0.295
Ethyl Thiophene
0.651
0.015
This translates to a relative volatility of 3.19 for the system ethanol/ethyl acetate in the ternary system shown above, the ethanol being the distillate.
Experiment 3
An ethanol/ethyl acetate mixture with a molar ratio of 1:1 has a relative volatility of 0.91.
The separation was effected by using a suitable paraffin as an extractive is distillation solvent. A mixture of ethanol (9.7 g), ethyl acetate (17.7 g) and dodecane (238.2 g) was charged into the flask 12 of the vapour-liquid equilibrium still 10 and the above procedure was applied. The liquid and vapour phases were analysed. The liquid and vapour molar fractions were determined to be as follows:
TABLE 3
Liquid (mole
Vapour (mole
Component
fraction)
fraction)
Ethanol
0.116
0.707
Ethyl Acetate
0.111
0.280
Dodecane
0.773
0.013
This translates to a relative volatility of 2.41 for the system ethanol/ethyl acetate in the ternary system shown above, the ethanol being the distillate.
An ethanol/water liquid mixture with a molar ratio of 1.25:1 has a relative volatility of 1.71.
The separation was effected by using a suitable amine as an extractive distillation solvent.
A mixture of ethanol (23.7 g), water (7.4 g) and diethylenetriamine (330.7 g) was charged into the flask 12 of the vapour-liquid equilibrium still 10 and the above procedure was applied. The liquid and vapour phases were analysed. The liquid and vapour molar fractions were determined to be as follows:
TABLE 4
Liquid (mole
Vapour (mole
Component
fraction)
fraction)
Ethanol
0.125
0.750
Water
0.100
0.250
Diethylenetriamine
0.776
0.000
This translates to a relative volatility of 2.4 for the system ethanol/water in the ternary system shown above, the ethanol being the distillate.
Experiment 5
An ethanol/water liquid mixture with a molar ratio of 4:1 has a relative volatility of 1.12.
The separation was effected by using a suitable amine as an extractive distillation solvent.
A mixture of ethanol (11.1 g), water (1.1 g) and 1,3-diaminopentane (197.7 g) was charged into the flask 12 of the vapour-liquid equilibrium still 10 and the above procedure was applied. The liquid and vapour phases were analysed. The liquid and vapour molar fractions were determined to be as follows:
TABLE 5
Liquid (mole
Vapour (mole
Component
fraction)
fraction)
Ethanol
0.108
0.732
Water
0.027
0.242
1,3-diaminopentane
0.865
0.026
This translates to a relative volatility of 1.33 for the system water/ethanol in the ternary system shown above, the water being the distillate.
Experiment 6
An ethanol/water mixture with a molar ratio of 0.9:1 has a relative volatility of 2.07.
The separation was effected by using a suitable chlorinated hydrocarbon as an extractive distillation solvent.
A mixture of ethanol (16.34 g), water (7.1 g) and hexachlorobutadiene (372.2 g) was charged into the flask 12 of the vapour-liquid equilibrium still 10 and the above procedure was applied. The liquid and vapour phases were analysed. The liquid and vapour molar fractions were determined to be as follows:
TABLE 6
Liquid (mole
Vapour (mole
Component
fraction)
fraction)
Ethanol
0.163
0.682
Water
0.181
0.311
Hexachlorobutadiene
0.656
0.007
This translates to a relative volatility of 2.43 for the system ethanol/water in the ternary system shown above, the ethanol being the distillate. | A method of separating ethanol and ethyl acetate, and ethanol and water involves distilling a mixture of the components by an extractive distillation process in the presence of an extractive distillation solvent. The extractive distillation solvent may be an amine, an alkylated thiopene, and paraffins. | 2 |
This application is a continuation in part of U.S. Ser. No. 10/425,934 filed Apr. 30, 2003.
FIELD OF THE INVENTION
The present invention pertains to a coupling assembly for releasably securing separable parts together, and especially for securing together components of a wear assembly used in excavating or the like.
BACKGROUND OF THE INVENTION
Excavating equipment typically includes various wear parts to protect underlying products from premature wear. The wear part may simply function as a protector (e.g., a wear cap) or may have additional functions (e.g., an excavating tooth). In either case, it is desirable for the wear part to be securely held to the excavating equipment to prevent loss during use, and yet be capable of being removed and installed to facilitate replacement when worn. In order to minimize equipment downtime, it is desirable for the worn wear part to be capable of being easily and quickly replaced in the field. Wear parts are usually formed of three (or more) components in an effort to minimize the amount of material that must be replaced on account of wearing. As a result, the wear part generally includes a support structure that is fixed to the excavating equipment, a wear member that mounts to the support structure, and a lock to hold the wear member to the support structure.
As one example, an excavating tooth usually includes an adapter as the support structure, a tooth point or tip as the wear member, and a lock or retainer to hold the point to the adapter. The adapter is fixed to the front digging edge of an excavating bucket and includes a nose that projects forward to define a mount for the point. The adapter may be a single unitary member or may be composed of a plurality of components assembled together. The point includes a front digging end and a rearwardly opening socket that receives the adapter nose. The lock is inserted into the assembly to releasably hold the point to the adapter.
The lock for an excavating tooth is typically an elongate pin member which is fit into an opening defined cooperatively by both the adapter and the point. The opening may be defined along the side of the adapter nose, as in U.S. Pat. No. 5,469,648, or through the nose, as in U.S. Pat. No. 5,068,986. In either case, the lock is inserted and removed by the use of a large hammer. Such hammering of the lock is an arduous task and imposes a risk of harm to the operator.
The lock is usually tightly received in the passage in an effort to prevent ejection of the lock and the concomitant loss of the point during use. The tight fit may be effected by partially unaligned holes in the point and adapter that define the opening for the lock, the inclusion of a rubber insert in the opening, and/or close dimensioning between the lock and the opening. However, as can be appreciated, an increase in the tightness in which the lock is received in the opening further exacerbates the difficulty and risk attendant with hammering the locks into and out of the assemblies.
The lock additionally often lacks the ability to provide substantial tightening of the point onto the adapter. While a rubber insert will provide some tightening effect on the tooth at rest, the insert lacks the strength needed to provide any real tightening when under load during use. Most locks also fail to provide any ability to be re-tightened as the parts become worn. Moreover, many locks used in teeth are susceptible to being lost as the parts wear and the tightness decreases.
These difficulties are not limited strictly to the use of locks in excavating teeth, but also apply to the use of other wear parts used in excavating operations. In another example, the adapter is a wear member that is fit onto a lip of an excavating bucket, which defines the support structure. While the point experiences the most wear in a tooth, the adapter will also wear and in time need to be replaced. To accommodate replacement in the field, the adapters can be mechanically attached to the bucket. One common approach is to use a Whisler style adapter, such as disclosed in U.S. Pat. No. 3,121,289. In this case, the adapter is formed with bifurcated legs that straddle the bucket lip. The adapter legs and the bucket lip are formed with openings that are aligned for receiving the lock. The lock in this environment comprises a generally C-shaped spool and a wedge. The arms of the spool overlie the rear end of the adapter legs. The outer surfaces of the legs and the inner surfaces of the arms are each inclined rearward and away from the lip. The wedge is then ordinarily hammered into the opening to force the spool rearward. This rearward movement of the spool causes the arms to tightly pinch the adapter legs against the lip to prevent movement or release of the adapter during use. As with the mounting of the points, hammering of the wedges into the openings is a difficult and potentially hazardous activity.
In many assemblies, other factors can further increase the difficulty of removing and inserting the lock when replacement of the wear member is needed. For example, the closeness of adjacent components, such as in laterally inserted locks (see, e.g., U.S. Pat. No. 4,326,348), can create difficulties in hammering the lock into and out of the assembly. Fines can also become impacted in the openings receiving the locks making access to and removal of the locks difficult. Additionally, in Whisler style attachments, the bucket must generally be turned up on its front end to provide access for driving the wedges out of the assembly. This orientation of the bucket can make lock removal difficult and hazardous as the worker must access the opening from beneath the bucket and drive the wedge upward with a large hammer. The risk is particularly evident in connection with dragline buckets, which can be very large. Also, because wedges can eject during service, it is common practice in many installations to tack-weld the wedge to its accompanying spool, thus, making wedge removal even more difficult.
There has been some effort to produce non-hammered locks for use in excavating equipment. For instance, U.S. Pat. Nos. 5,784,813 and 5,868,518 disclose screw driven wedge-type locks for securing a point to an adapter and U.S. Pat. No. 4,433,496 discloses a screw-driven wedge for securing an adapter to a bucket. While these devices eliminate the need for hammering, they each require a number of parts, thus, increasing the complexity and cost of the locks. The ingress of fines can also make removal difficult as the fines increase friction and interfere with the threaded connections. Moreover, with the use of a standard bolt, the fines can build up and become “cemented” around the threads to make turning of the bolt and release of the parts extremely difficult.
SUMMARY OF THE INVENTION
The present invention pertains to an improved coupling assembly for releasably holding separable parts together in a secure, easy, and reliable manner. Further, the lock of the present invention can be installed and removed simply by using a manual or powered wrench. The need to hammer or pry the lock into and out of the assembly is eliminated.
The present invention is particularly useful for securing a wear member to a support structure in conjunction with an excavating operation. The lock of the present invention is easy to use, is securely held in the wear assembly, alleviates the risk associated with hammering a lock into and out of a wear assembly, and operates to effectively tighten the wear member onto the support structure.
In one aspect of the invention, a tapered lock member is formed with a threaded formation that is used to pull the lock member into a locking position in the assembly. The lock member, then, bears against the assembly to hold the components of the assembly together. The use of a threaded formation on the lock member also reduces the risk that the lock member will be ejected during use as compared to a lock that is simply hammered into place.
In another aspect of the present invention, a wedge and a spool are threadedly coupled together to drive the wedge into and out of the wear assembly without hammering. The direct coupling of the wedge and spool eliminates the need for bolts, washers, nuts and other hardware so as to minimize the number of parts. As a result of this efficient construction, the lock is inexpensive to make, easy to use, and unlikely to become inoperative because of lost or broken parts or due to fines or other difficulties encountered in harsh digging environments. Further, the wedge can be selectively driven into the assembly to provide the degree of tightness necessary for the intended operation and/or to re-tighten the assembly after incurring wear during use.
In one preferred construction, the wedge includes a thread formation with a wide pitch to form a sizable land segment by which the wedge can directly apply pressure to the wear assembly for holding the wear member to the support structure. In one embodiment, the wedge is formed with a helical groove along its outer periphery to engage helical ridge segments formed in a generally trough shaped recess along the spool or other part of the assembly. Rotation of the wedge moves the wedge along the spool, and into and out of the wear assembly. Movement of the wedge into the assembly increases the depth of the lock, and thereby tightens the engagement of the wear member onto the support structure.
A latch assembly is preferably provided to securely hold the wedge in place and avoid an undesired loss of parts during use. In one preferred construction, the wedge is formed with teeth that interact with a latch provided in an adjacent component such as the spool, wear member or support structure. The teeth and latch are formed to permit rotation of the wedge in a direction that drives the wedge farther into the opening, and to prevent rotation in a direction that retracts the wedge. The latch may also function to retain the lock in the assembly when the wear member and/or support structures begin to wear.
The inventive lock is simple, sound, reliable, and requires only minimal components. The lock is also intuitively easy for the operator to understand. Elimination of hammering also makes replacement of a wear member easy and less hazardous. Moreover, the lock is able to provide selective tightening of the wear assembly to facilitate re-tightening of the wear members or a better original mounting when, for example, the support structure is partially worn. These and other advantageous will be evident in the drawings and description to follow.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a coupling assembly in accordance with the present invention securing a point to an adapter.
FIG. 2 is a side view of a lock in accordance with the present invention.
FIG. 3 is a perspective view of a wedge of the lock.
FIG. 4 is an enlarged, partial, perspective view of the wedge.
FIG. 5 is a perspective view of a spool of the lock.
FIG. 6 is a perspective view of a wear member having a latch of the inventive coupling assembly.
FIG. 7 is a partial, exploded, perspective view of the wear member shown in FIG. 6 .
FIG. 8 is a cross-sectional view of the coupling assembly taken along line 8 — 8 in FIG. 1 in the assembled condition.
FIG. 9 is a perspective view of an alternative spool for the lock.
FIG. 10 is an exploded, perspective view of the alternative spool.
FIG. 11 is a side view of a second lock in accordance with the present invention including the alternative spool. This lock is adapted to secure an adapter to a bucket lip in a Whisler style connection.
FIG. 12 is a cross-sectional view along a longitudinal axis of another wear assembly using the lock of FIG. 11 .
FIG. 13 is a cross-sectional view along the same line as FIG. 12 for an alternative embodiment including an insert between the wedge and support structure.
FIG. 14 is a perspective view of the insert used in the alternative embodiment of FIG. 13 .
FIG. 15 is a perspective view of an alternative wedge construction.
FIG. 16 is a perspective view of another alternative wedge construction.
FIG. 17 is a cross-sectional view along the same line as FIG. 12 for an alternative embodiment.
FIG. 18 is a cross-sectional view along the same line as FIG. 12 for another alternative embodiment.
FIG. 18 a is a cross-sectional view illustrating shifting of the wear member on a lock without a cradle.
FIG. 18 b is a cross-sectional view illustrating shifting of the wear member on a lock with cradle.
FIG. 19 is a perspective view of a cradle used in the alternative embodiment shown in FIG. 18 with the wear member omitted.
FIG. 20 is a cross-sectional view along the same line as FIG. 12 for another alternative embodiment.
FIG. 21 is a cross-sectional view along the same line as FIG. 12 for another alternative embodiment.
FIG. 22 is a cross-sectional view along the same line as FIG. 12 for another alternative embodiment.
FIG. 23 is an perspective view of another alternative embodiment wherein the wear member is partially fit onto a lip.
FIG. 24 is a side view of the embodiment of FIG. 23 in the same orientation.
FIG. 25 is a partial cross-sectional view of the fit of the wear member in FIG. 23 with the hole in the lip when fully fit on the lip.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The present invention pertains to a coupling assembly for releasably holding separable parts together. While the invention has a broader application, it is particularly useful in releasably securing a wear member to a support structure in an excavating operation. The wear member may, for example, be a point, an adapter, a shroud or other replaceable component.
In one preferred construction, the lock 10 includes a wedge 12 and a spool 14 ( FIGS. 2–5 ). Although the lock can be used to secure a wide range of components together, it is shown in FIG. 1 holding together the parts of an excavator tooth. In this embodiment of the invention, the lock is placed in a wear assembly 15 wherein the support structure is formed as an adapter 17 and the wear member is defined as a point or tip 19 . Lock 10 is received into an opening 21 in wear assembly 15 that is cooperatively defined by holes 23 in point 19 and hole 25 in adapter 17 so as to releasably hold the point to the adapter ( FIGS. 1 and 8 ). Holes 23 and 25 are each preferably elongated longitudinally to prevent misalignment of the wedge and spool, although the holes could be circular or have other shapes.
The wedge 12 preferably has a frusto-conical shape with a rounded exterior surface 16 that tapers toward a front end 18 ( FIGS. 1–4 ). A thread formation 22 , preferably in the form of a helical groove 20 with a wide pitch, is formed along the exterior surface 16 of the wedge. Accordingly, a rather wide, helically shaped land segment 24 exists between the adjacent spiraling groove segments. This land segment presents a large surface area to press against the front surface 31 of the hole 25 in adapter 17 and the wall 37 of recess 36 in spool 14 . The relatively large land segment enables the lock to resist large loads with acceptable levels of stress and without the need for threads to be formed in the wall of hole 25 in the adapter. The wide pitch of the groove 20 also permits the wedge to be quickly moved into and out of the opening 21 .
In one preferred construction, the pitch of the thread on the wedge is on the order of one inch and the groove forming the thread about ⅛ of an inch wide, although the pitch and groove width could vary widely. The groove is preferably formed with curved corners to form a robust thread that is not susceptible to peening or other damage. The rear end 27 of the wedge is provided with a turning formation 29 to facilitate engagement with a tool, such as a wrench, for turning the wedge. In the preferred embodiment, formation 29 is a square socket, although other arrangements could be used.
The taper of the wedge can be varied to provide an increased or decreased take-up of the wear member on the support structure. For example, if the taper of the wedge is increased, the rate at which the wear member moves to the set position on the support structure is increased, but at the expense of tightening force (i.e., more torque is required to turn the wedge). The taper of the wedge can be designed to match the particular task. In all cases the holding power of the lock would be about the same so long as the wedge is not formed too small at the forward end to provide sufficient strength.
The spool 14 preferably has a generally C-shaped configuration with a body 26 and arms 28 ( FIGS. 1 , 2 and 5 ). In this example, the arms are fairly short so as to press against the rear wall portions 30 of holes 23 in point 19 ( FIG. 8 ). However, the particular shape and size of the arms can vary widely depending on the construction and use of the parts receiving the lock. Additionally, the arms could be omitted entirely if the opening in the support structure were sized to permit the rear wall of the body to press against the rear wall portions in the openings of the wear member and the spool was adequately anchored. Similarly, in this type of construction, the lock could be reversed such that the wedge pressed against the wear member and the spool against the support structure.
The body 26 of spool 14 is formed with a generally trough shaped recess 36 to receive a portion of the wedge ( FIG. 5 ). The recess is provided with a thread formation 42 that is defined as at least one projection to fit within groove 20 . In this way, the wedge and spool are threadedly coupled together. Although the projection can take the form of a wide range of shapes and sizes, recess 36 preferably includes multiple ridges 40 on the spool to complement groove 20 on wedge 12 . The ridges 40 are shaped as helical segments having the same pitch as the helical groove 20 so that the ridges are received into the groove to move the wedge in or out of the opening when the wedge is rotated. While ridges 40 are preferably provided along the entire length of recess 36 , fewer ridges or even one ridge could be provided if desired. Further, each ridge preferably extends across the entire recess 36 , but can have a lesser extension if desired.
In the preferred construction, the helical groove 20 has the same pitch along the length of the wedge. Since the wedge is tapered, the angle of the thread changes to become more shallow as the groove extends from the forward end 18 to the rear end 27 . This variation requires the allowance of clearance space between the internal and external thread so they can cooperate and avoid binding with each other. This construction, then, forms relative loose fitting threads.
As an alternative construction, a ridge(s) to engage groove 20 on the wedge could be formed on the front wall portion of the hole 23 defined in point 19 in addition to or in lieu of the ridges 40 on the spool. The ridge could simply be provided by the body 62 , as seen in FIGS. 6 and 7 , but could also include an extension and/or other ridges on the front wall portion of the hole, similar to the inclusion of body 62 a in spool 14 a (as seen in FIGS. 9 and 10 ). Similarly, one or more ridges (or other projections) to engage groove 20 could instead be formed on the wall structure of the hole 25 in adapter 17 (in addition to or in lieu of the other ridges). In these alternatives where a thread formation is formed on the point and/or adapter, the wedge could be inserted into the opening without a spool to hold the wear member to the support structure. As can be appreciated, the hole in the point would need to be smaller to permit direct bearing contact between the wedge and the rear wall portions of the holes in the point or the ridge provided on the rear wall of the opening.
The thread formations may also be reversed so that grooves are formed in the point, adapter and/or spool to receive a helical ridge formed on the wedge. While a ridge may be used to form the thread on the wedge with grooves only in the spool and not in the adapter wall (or vice versa), the ridges do not form as good a bearing surface as land segment 24 without the matching grooves in the opposing surfaces. Nevertheless, a helical ridge on the wedge may be used even with a smooth adapter wall and/or smooth recess in the spool in lower stress environments. In this alternative, the wedge 94 would preferably have a ridge 96 with a blunt outer edge 98 ( FIG. 15 ). Nevertheless, the provision of a ridge on the wedge could be designed to bite into the adapter wall and/or spool. Finally, the wedge 101 could be formed with a tapping ridge 103 that cuts a thread in the spool and/or adapter wall as it is threaded into the assembly ( FIG. 16 ).
Recess 36 in spool 14 preferably tapers toward one end 38 to complement the shape of the wedge and position forward portions of the land segment 24 bearing against the adapter to be generally vertical for a solid, secure contact with the nose of adapter 17 ( FIGS. 5 and 8 ). This orientation stabilizes the wedge and lessens the stresses engendered in the components when the wedge is inserted tightly into the wear assembly 15 . In a preferred construction, the recess is tapered at twice the taper of the wedge so as to place forward portions of the land segment 24 in a vertical orientation (as illustrated). As can be appreciated, the purpose of this construction is to orient the forward portions of the land segment substantially parallel to the wall of the member which they engage as opposed being in a strictly vertical orientation. In the preferred construction, recess 36 is provided with a concave curve that is designed to complement the shape of the wedge when the wedge is at the end of its projected travel in a tightening direction. In this way, the wedge is best able to resist the applied loads and not bind with the spool during tightening. Nevertheless, other shapes are possible.
In use, lock 10 is inserted into opening 21 in the wear assembly 15 when the wear member 19 is mounted on the nose 46 of adapter 17 ( FIGS. 1 and 8 ). The lock 10 is preferably placed into opening 21 as separate components (i.e., with the spool being inserted first) but may in some cases be inserted collectively as a unit (i.e., with the wedge placed partially into the recess 36 ). In either case, the free ends 50 of arms 28 are placed in engagement with the rear wall portions 30 of holes 23 in wear member 19 . The wedge is then rotated to drive it into opening 21 so that the forward portions of land segment 24 of wedge 12 press against the front wall portion 31 of hole 25 , and arms 28 of spool 14 press on the rear wall portions 30 of holes 23 . Continued rotation of the wedge further enlarges the depth of the lock (i.e., the distance in a direction parallel to the axis of the movement of the point onto the adapter nose) so that the arms 28 push the wear member 19 farther onto the support structure 17 . This rotation is stopped once the desired tightness has been achieved. By using a tapered wedge in the lock receiving opening 21 , a significant clearance exists between much of the wedge and the walls of the opening. As a result, fines from the digging operation would generally not become firmly impacted into the opening. Even if fines did become impacted in the opening, the wedge would still be easily retracted by turning the wedge with a wrench. The tapered shape of the wedge makes the opening around the lock larger at the bottom of the assembly in the illustrated orientation. With this arrangement, the fines tend to fall out as the wedge is loosened. The relatively wide groove in the wedge in the preferred construction also tends to enable release of fines from the lock and thereby avoid having the lock becoming “cemented” into the assembly. Moreover, because of the tapered shape of the threaded wedge, the assembly is quickly loosened with just a short turn of the wedge. Rubber caps or the like (not shown) could be used to inhibit the ingress of fines in socket 29 if desired.
In a preferred construction, a latching assembly 56 is provided to retain the wedge in the opening. As seen in FIGS. 2–4 and 8 , ratchet teeth 58 are preferably provided within groove 20 to cooperate with a latch 60 . By being recessed within the groove, the teeth do not disrupt the threaded coupling of the wedge and the spool, or the engagement of the wedge with support structure 17 and spool 14 . The ratchet teeth are adapted to engage latch 60 , which is mounted in either the wear member 19 ( FIGS. 6–8 ), spool 14 ( FIGS. 10 and 12 ) or support structure 17 (not shown). The teeth are inclined to permit rotation of the wedge in a tightening direction but prevent rotation in a loosening direction. The teeth generally need to be only formed along about one third the length of groove 20 to ensure engagement of the latch with the teeth when the wedge is fully tightened for use. Of course, the teeth could be positioned along more or less than about one-third the length of the groove as desired. The number of teeth and their location on the wedge depend largely on the amount of travel expected between the parts being coupled together, and the expected wear of the components and retightening of the lock. The teeth will preferably be positioned along the rear end of the wedge, i.e., where the wedge is widest, so that the latch 60 is securely engaged against the teeth and stress in the wedge is minimized. Nevertheless, other arrangements are possible. The teeth may have a reversible style that inhibits unwanted turning in both directions, but which will permit turning under the force of a wrench or the like—i.e., the detent can retract under sufficient load to permit rotation of the wedge in the tightening or untightening directions. Further, omission of the teeth is possible. Another alternative is to design latch 60 to apply a force on the wedge to frictionally inhibit inadvertent turning of the wedge during use.
Latch 60 preferably comprises a body 62 and a resilient member 63 that are fit within a cavity 64 that is open in one of the holes 23 ( FIGS. 6 and 7 ). The body is provided with a detent 65 to engage ratchet teeth 58 on the wedge 12 . The resilient member presses the detent 65 into engagement with the ratchet teeth and permits the body to retract into the cavity as the wider portions of the wedge are driven into opening 21 . In the preferred construction, body 62 includes a helical ridge 66 that complements ridges 40 on spool 14 , i.e., the ridge has the same pitch and is positioned to match the trajectory of ridges 40 . Since the spool is placed into opening 21 by the operator, cavity 64 may receive body 62 with clearance to enable the body to shift as needed to ensure that ridge 66 complements ridges 40 . The clearance need not be great (e.g., on the order of 0.03 of an inch in larger systems) because the spool has only a small range of adjustment where it can be properly positioned with the arms against the walls defining holes 23 . Additionally, groove 20 could be formed with a narrowing width as it extends from front end 18 of wedge 12 toward rear end 27 . In this way, the groove could become easily engaged with ridges 40 on spool 14 and ridge 66 on body 62 , even if initially misaligned, and gradually shift body 62 into alignment with ridge 40 as the groove narrows. The body 62 is preferably bonded to resilient member 63 by an adhesive (or via casting), which in turn, is bonded in cavity 64 by an adhesive. Nevertheless, the body and resilient member could be held in cavity 64 by friction or other means. The body is preferably composed of plastic, steel or any other material that provides the requisite force to hold the wedge from turning during operation of the excavator and the resilient member of rubber, although other materials could be used.
In use, ridge 66 is received into groove 20 . As the wedge reaches a tightened position, detent 65 engages teeth 58 . However, due to the inclination of the teeth and the provision of resilient member 63 , the latch rides over the teeth as the wedge is rotated in the tightening direction. The detent 65 locks with teeth 58 to prevent any reverse rotation of the wedge. The detent is designed to be broken from body 62 when the wedge is turned in the release direction with a wrench. The force to break the detent is within normal forces expected to be applied by a wrench but still substantially more torque than would be expected to be applied to the wedge through normal use of the excavating tooth. Alternatively, a slot or other means could be provided to permit retraction of the latch and disengagement of the detent from the teeth for reverse rotation of the wedge. Receipt of the ridge 66 and ridges 40 in groove 20 function to retain the wedge in opening 21 even after looseness develops in the tooth on account of wearing of the surfaces.
Alternatively, the latch 60 could be positioned within a cavity formed along the front wall portion 51 of hole 25 in adapter 17 . The latch would function in the same way as described above when mounted in point 19 . In addition, an insert (not shown) could be positioned between wedge 12 and front wall portion 51 of hole 25 if desired. The insert may include a recess with ridges like recess 36 in spool 14 or simply have a smooth recess to receive the wedge. The insert could be used to fill the space of a large opening in the adapter (or other support structure) or to accommodate a wedge formed with threads having a smaller pitch for greater mechanical advantage or other reasons, and still provide a large surface area with which to bear against the adapter. Further, the front surface of the insert may be formed to mate with the front wall portion 51 of hole 25 to increase the bearing area between the adapter and the lock, and thereby reduce the induced stresses in the parts. A latch or the like may also be used to retain the insert in place. A latch, like latch 60 , could also be provided in the insert.
In an alternative embodiment ( FIGS. 9 and 10 ), lock 10 a has the latch 60 a mounted in a cavity 64 a formed in recess 36 a of spool 14 a . In the same way as latch 60 , latch 60 a preferably includes a body with a helical ridge 66 a and detent 65 a , and a resilient member 63 a . Latch 60 a would operate in the same way as discussed above for latch 60 . The teeth 58 on the wedge would be formed in the same way, irrespective of whether the latch is mounted in the spool, the wear member or the support structure. As seen in FIG. 9 , ridge 66 a would be positioned as a continuation of one of the ridges 40 . Although latch 60 is shown aligned with the ridge 40 closest to rear end 27 of the wedge, the latch could be formed anywhere along recess 36 a . If the latch were repositioned, the teeth 58 on wedge 12 may also need to be re-positioned in the groove 20 to engage the detent 65 a of latch 60 a.
Lock 10 a is illustrated with a spool 14 a that is adapted for use in a Whisler-style attachment ( FIGS. 11 and 12 ). Nevertheless, a spool with a latch, like latch 60 a , could be used to secure a point to an adapter, a shroud to a lip, or to secure other separable components together. In the illustrated embodiment, arms 28 a of spool 14 a are formed with inner surfaces 70 that diverge as they extend away from body 26 a to mate with the inclined surfaces 72 conventionally formed on the rear end of a Whisler-style adapter 17 . In use, the bifurcated legs 74 of the adapter 17 straddle the lip 76 of the excavating bucket. Each of the legs includes an elongated hole 78 that is aligned with hole 80 formed in lip 76 . The aligned holes 78 , 80 cooperatively define an opening 82 into which lock 10 a is received. As with lock 10 , lock 10 a is preferably installed as separate components with the spool 14 a being installed in opening 82 first, but may possibly be installed as a unit with the wedge 12 only partially placed into recess 36 a . In either event, once the lock 10 a is inserted into opening 82 , the wedge is rotated in the tightening direction to drive the wedge into the opening 82 ( FIG. 12 ). The driving is continued until the spool arms sufficiently grip the adapter against lip. With elongated holes 78 in legs 74 , the latch needs to be mounted in spool 14 or lip 80 . Nevertheless, when used with such elongated openings, the lock can be re-tightened as needed in this arrangement after wear begins to occur in order to maintain the assembly in a tightened state. The variety of lock embodiments discussed above for use with the tooth can also be used in a Whisler style connection.
As noted above, an insert 90 can be provided as part of the lock between the front wall portion of the hole in the support structure and the wedge ( FIGS. 13 and 14 ). In the illustrated embodiment, lock 10 b is the same as lock 10 a with the addition of insert 90 ; hence, common reference numbers have been used. The insert preferably includes a rear surface 91 provided a smooth recess to complement the shape of the wedge when the wedge is in the fully advanced position, although other shapes and/or the provision of ridges to be received in groove 20 (in addition to or in lieu of ridges 40 ) are possible. To prevent movement of the insert during turning of the wedge, the insert preferably includes lips 92 that are welded to lip 76 . Nevertheless, a latch or other means could be used to secure the insert in place. The insert functions to protect the lip from wear and/or to fill an enlarged opening in the lip or other components.
A lock in accordance with the present invention could be used to secure other styles of adapters (or other wear members) to a bucket lip, such as disclosed in U.S. Pat. No. 6,986,216, which is hereby incorporated by reference in Its entirety, or as disclosed in co-pending patent application Ser. No. 10/425,605 filed Apr. 30, 2003, entitled Wear Assembly for Excavating Digging Edge, also herein incorporated in Its entirety by reference.
Other various alternatives can be used to provide additional support or to reduce the stress within the wedge during use and thereby increase the life of the components.
As one example, a wedge 12 and spool 114 ( FIG. 17 ), having essentially the same construction as spool 14 a (although other variations are possible), are shown holding an adapter 119 to a lip 176 of an excavating bucket. In this example, the ends of legs 174 of adapter 119 are adapted to fit against stop blocks 120 for additional support, although the stop blocks are not essential and could be omitted. In addition, insert 190 , between wedge 12 and the front wall of the opening 180 in the lip, is provided with extended arms 192 to overlie the inner and outer surface of the lip. These extended arms provide additional support for the insert and increased surfaces by which the arms can be welded to the lip. As can be appreciated, a clearance 193 can be provided within the adapter to accommodate the increased arm length.
In a further example ( FIGS. 18 and 19 ), a cradle 200 provided between the insert 190 a and wedge 12 . Cradle 200 preferably includes a trough shaped rear surface 202 (like surface 91 of insert 90 in FIG. 14 ) to bear against the wedge (although other surfaces are possible), and a curved, concave front face 204 (i.e., curved generally about a transverse axis). In this embodiment, the rear surface 191 a of insert 190 a complements cradle surface 204 so as to be curved generally about a transverse axis (instead of a vertical axis as shown, e.g., in FIG. 14 for insert 90 ). Nevertheless, front surface 204 of cradle 200 could also have a concave, curved form to define a generally vertical tough to receive insert 190 generally as spool 14 a or insert 90 receive wedge 12 . The rear wall 191 a of the insert 190 a , then, would have a complementary convex or crowned surface shape be received with in the formed trough. The trough and crowned surface could also be reversed with the trough on the insert and the crowned surface on the cradle. The front wall of opening 180 in lip 176 could be formed with the convex wall to directly abut the front face 204 of cradle 200 , but an insert 190 is preferred to protect the lip and enable the fit with existing lip constructions.
When adapter 119 is used, the applied loads will tend to cause the adapter legs 174 to shift longitudinally, i.e., forward and rearward, along the inside and outside surfaces of the lip 176 . Although the use of stop blocks 120 will limit the rearward motion, the legs will still tend to pull forward. In any event, this shifting of the legs can apply substantial compressive loading on the wedge and a build up of stress on the wedge, which leads to a reduced usable life. By using cradle 200 , the wedge 12 and cradle 200 can swing about insert 190 a (i.e., about the generally transverse axis) to accommodate the alternative shifting of the legs and thereby reduce the stress in the wedge, thus, increasing the usable life of the wedge.
For example, as shown in FIGS. 18 a and 18 b , the application of a downward load on the front of the adapter will tend to cause the upper leg of adapter 119 to shift forward along the inside surface of the lip 176 . When used without stop blocks 120 , there will also be a concomitant rearward shifting of the lower leg. In regard to the present example, this forward shifting of the upper leg can cause a high compressive force to be applied to the wedge and create an interference fit H of certain magnitude that is usually accommodated by compression of the wedge. With the use of a cradle, as illustrated in FIG. 18 b , the forward shifting of the upper leg is at least partially accommodated by shifting of the cradle so that the interference fit h is smaller in magnitude than interference H for the same amount of forward shifting of the adapter leg. The shifting of the wedge enables the lock to automatically adjust so as to increase the contact surface area resisting the loads and thereby reduce the likelihood of localized peening or other damage to the lock components—particularly the wedge.
In an alternative embodiment ( FIG. 20 ), cradle 210 includes a curved convex front surface 212 (i.e., curved about a generally transverse axis) to be received against a concave rear surface of insert 190 b . In this embodiment, the cradle and wedge are adapted to shift to accommodate the shifting of the legs of the adapter 119 under load as discussed above for cradle 200 .
As another alternative construction ( FIG. 21 ), cradle 220 is formed with a front face 224 having an offset formation. More specifically, front face 224 includes an upper portion 225 and a lower portion 226 , each having a convex curvature such as used in cradle 210 . The central portion 227 of front face 224 has recessed convex curved surface preferably about the same radius of curvature origination point as upper and lower portions 225 , 226 . Insert 190 b has a complementary rear surface. Cradle 220 , thus, operates in essentially the same way as cradle 210 , but is thinner for use in smaller openings in lip 176 and adapter 119 .
As another alternative, cradle 230 can be used with a shortened wedge 112 to accommodate the shifting of the adapter legs 174 . In this embodiment, the spool is also eliminated. More specifically, cradle 230 includes a convex front face 234 , in generally the same way as cradle 210 . However, cradle 230 also includes an extended arm 231 which abuts against the lower leg 174 in place of spool 14 .
Further, cradles can be used in the same way with conventional wedge and spool arrangements (i.e., non-rotating wedges) to provide the same shifting of the lock to better accommodate shifting of the legs.
In another alternative embodiment ( FIGS. 23–25 ), the spool 314 is formed integrally with the wear member 319 . In this construction, a shroud 319 or other wear member includes a pair of legs 374 to straddle the lip 376 . One leg 374 a (in this example, the inner leg) is formed with an opening 378 for receiving a wedge 12 . A spool 314 is cast (or otherwise formed) as an integral portion of leg 374 to form the rear wall of opening 378 . Spool 314 is provided with the same front construction as disclosed above for spool 14 a (or spool 14 ). Spool 314 further projects from an inner side 375 of leg 374 to fit within hole 380 in lip 376 against rear wall 381 . Leg 374 b is shorter than leg 374 a to enable the wear member 319 to swing onto lip 376 and place shroud 314 into opening 380 . In FIGS. 23 and 24 , wear member 319 is shown partially swung about lip 376 with shroud 314 about to be placed within hole 380 in lip 376 . Once wear member 319 is fully fit on lip 376 , wedge 12 is inserted and tightened as disclosed above.
The lock of the present invention can also be used in a variety of different assemblies to hold separable parts together. While the invention is particularly suited for use in securing a point to an adapter, and an adapter or shroud to a lip, the invention can be used to secure other wear members in excavating operations, or simply other separable components that may or may not be used in excavating operations. Further, the above-discussion concerns the preferred embodiments of the present invention. Various other embodiments as well as many changes and alterations may be made without departing from the spirit and broader aspects of the invention as defined in the claims. | A lock that includes a wedge that is used to releasably secure separable components of an assembly together. The wedge can be used with a spool. The wedge and spool are threadedly coupled together to drive the wedge into and out of an opening in the assembly without hammering or prying. The direct coupling of the wedge and spool eliminates the need for bolts, washers, nuts and other hardware so as to minimize the number of parts. As a result, the lock is inexpensive to make, easy to use, and unlikely to become inoperative because of lost or broken parts or due to fines or other difficulties encountered in harsh digging environments. Further, the wedge can be driven into the assembly to provide the degree of tightness necessary for the intended operation and/or to re-tighten the assembly after incurring wear during use. A latch assembly is preferably provided to securely hold the wedge in place and avoid an undesired loss of parts during use. | 4 |
BACKGROUND
The present invention relates to tin or tin alloys, in which the α (alpha) dose has been reduced, for use in the production of semiconductors, etc., and a method for producing the same.
Generally, tin is a material used in the production of semiconductors, and is particularly a main raw material for solder materials. In the production of semiconductors, when a semiconductor chip and a substrate are bonded, and an Si chip, such as IC or LSI, is bonded to or sealed in a lead frame or a ceramics package, solder is used to form bumps during TAB (tape automated bonding) or during the manufacture of flip chips, and is used as a semiconductor wiring material.
Since recent semiconductor devices are highly densified and of low operation voltage and cell capacity, there is an increasing risk of soft errors caused by the influence of α rays emitted from materials in the vicinity of semiconductor chips. For this reason, there are demands for high purification of the aforementioned solder materials and tin, and demands for materials with lower α rays.
There are several disclosures relating to techniques for reducing α rays from tin. These techniques are described below. Document 1 discloses a method for producing low α-dose tin by alloying tin and lead having an α dose of 10 cph/cm 2 or less, and then removing the lead from the tin by refining. This technique is intended to reduce the α dose by diluting 210 Pb in the tin through the addition of high-purity Pb.
However, this method requires a complex process of removing Pb after being added to tin. Furthermore, the refined tin showed a significantly lower α dose in three years after refining; however, it can also be interpreted that the tin with a lower α dose cannot be used until three years later. Accordingly, this method is not considered to be industrially efficient.
Document 2 indicates that when 10 to 5,000 ppm of a material selected from Na, Sr, K, Cr, Nb, Mn, V, Ta, Si, Zr and Ba is added to Sn—Pb alloy solder, the radiation α particle count can be reduced to 0.5 cph/cm 2 or less.
However, even with the addition of such materials, the radiation α particle count could be reduced only to a level of 0.015 cph/cm 2 , which does not reach the level expected for current semiconductor device materials.
Another problem is that alkali metal elements, transition metal elements, heavy metal elements, and other elements that are undesirably mixed in semiconductors are used as the materials to be added. Therefore, it would have to be said that this is a low level material for assembling semiconductor devices.
Document 3 describes reducing the count of radiation α particles emitted from solder ultra fine wires to 0.5 cph/cm 2 or less, and using the same as the connection wiring of semiconductor devices. However, this level of count of radiation α particles does not reach the level expected for current semiconductor device materials.
Document 4 describes using highly-refined sulfuric acid, such as top-grade sulfuric acid, and highly-refined hydrochloric acid, such as top-grade hydrochloric acid, to form an electrolyte, and using high-purity tin as the anode to perform electrolysis, thereby obtaining high-purity tin having a low lead concentration and a lead α-ray count of 0.005 cph/cm 2 or less. It is natural that high-purity materials can be obtained by using high-purity raw materials (reagents) without regard to cost. Nevertheless, the lowest α-ray count of the deposited tin shown in an Example of Document 4 is 0.002 cph/cm 2 , which does not reach the expected level, despite the high cost.
Document 5 discloses a method for obtaining metallic tin of 5N or higher by adding nitric acid to a heated aqueous solution containing crude metallic tin to precipitate metastannic acid, followed by filtration and washing, then dissolving the metastannic acid, which was subject to washing, in hydrochloric acid or hydrofluoric acid, and performing electrowinning using the dissolution as an electrolyte. Document 5 vaguely states that this technique can be applied to semiconductor devices, but does not refer to limitation of radioactive elements or limitation of the radiation α particle count. Thus, Document 5 lacks interest in these limitations.
Document 6 shows a technique of reducing the amount of Pb contained in Sn, which constitutes a solder alloy, and using Bi, Sb, Ag or Zn as an alloy material. In this case, however, even though the amount of Pb is reduced as much as possible, no means are provided to fundamentally solve the problem of the radiation α particle count caused by the Pb being inevitably incorporated.
Document 7 discloses tin having a grade of 99.99% or higher and a radiation α particle count of 0.03 cph/cm 2 or less, produced by electrolysis using a top-grade sulfuric acid reagent. In this case, it is also natural that high-purity materials can be obtained by using high-purity raw materials (reagents) without regard to cost. Nevertheless, the lowest α-ray count of the deposited tin shown in an Example of Document 7 is 0.003 cph/cm 2 , which does not reach the expected level, despite the high cost.
Document 8 discloses lead as a brazing filler metal for use in semiconductor devices, which has a grade of 4N or higher, a radioisotope of less than 50 ppm, and a radiation α particle count of 0.5 cph/cm 2 or less. In addition, Document 9 discloses tin as a brazing filler metal for use in semiconductor devices, which has a grade of 99.95% or higher, a radioisotope of less than 30 ppm, and a radiation α particle count of 0.2 cph/cm 2 or less.
In Document 8 and Document 9, allowable values concerning the radiation α particle count are respectively lenient, and there is a problem in that the techniques of these documents do not reach the level expected for current semiconductor device materials.
In light of the above, the present applicant has proposed, as shown in Document 10, high-purity tin wherein the purity is 5N or higher (excluding gas components O, C, N, H, S, and P), especially the respective contents of U and Th as radioactive elements are 5 ppb or less, and the respective contents of Pb and Bi that emit radiation α particles are 1 ppm or less, in order to eliminate the influence of α rays on semiconductor chips as much as possible. In this case, the high-purity tin is produced by being finally melted and cast, and optionally being rolled and cut. Document 10 relates to a technique for realizing that the α-ray count of the high-purity tin is 0.001 cph/cm 2 or less.
When Sn is refined, Po, which is highly sublimable, sublimates upon heating in the production process, such as melting and casting process. If polonium isotope 210 Po is removed in the early stages of production, it is naturally considered that disintegration of polonium isotope 210 Po to lead isotope 206 Pb does not occur, and α rays are not generated.
This is because the generation of α rays in the production process presumably occurs during the disintegration of 210 Po to lead isotope 206 Pb. In fact, however, the generation of α rays was subsequently observed, although it was considered that Po was almost eliminated during production. Therefore, simply reducing the α-ray count of high-purity tin in the early stages of production was not a fundamental solution to the problem.
Patent Document 1: JP 3528532 B Patent Document 2: JP 3227851 B Patent Document 3: JP 2913908 B Patent Document 4: JP 2754030 B Patent Document 5: JP H11-343590 A Patent Document 6: JP H09-260427 A Patent Document 7: JP H01-283398 A Patent Document 8: JP S62-047955 B Patent Document 9: JP S62-001478 B Patent Document 10: WO 2007/004394
SUMMARY OF INVENTION
Technical Problem
Since recent semiconductor devices are highly densified and of low operation voltage and cell capacity, there is an increasing risk of soft errors caused by the influence of α rays emitted from materials in the vicinity of semiconductor chips. In particular, there are strong demands for high purification of solder materials or tin for use in the vicinity of semiconductor devices, and demands for materials with lower α rays. Accordingly, an object of the present invention is to clarify the phenomenon of the generation of α (alpha) rays in tin and tin alloys, and to obtain high-purity tin, in which the α dose has been reduced, suitable for the required materials, as well as a method for producing the same.
Solution to Problem
The following invention is provided to solve the above problem.
1) Tin characterized in that a sample of the tin after melting and casting has an α dose of less than 0.0005 cph/cm 2 .
2) Tin characterized in that the respective α doses of a sample of the tin measured one week, three weeks, one month, two months, six months, and thirty months after melting and casting are less than 0.0005 cph/cm 2 .
3) Tin characterized in that the first measured α dose of a sample of the tin is less than 0.0002 cph/cm 2 , and the difference between the first measured α dose and the α dose measured after the elapse of five months from the first measurement is less than 0.0003 cph/cm 2 .
4) The tin according to 1) or 2), characterized in that the first measured α dose of the sample is less than 0.0002 cph/cm 2 , and the difference between the first measured α dose and the α dose measured after the elapse of five months from the first measurement is less than 0.0003 cph/cm 2 .
5) The tin according to any one of 1) to 4), characterized in that the Pb content is 0.1 ppm or less.
6) The tin according to any one of 1) to 3), characterized in that the respective contents of U and Th are 5 ppb or less.
7) A tin alloy comprising 40% or more of the tin according to any one of 1) to 6).
8) A method for producing the tin according to any one of 1) to 6), characterized in that raw material tin having a purity level of 3N is leached in hydrochloric acid or sulfuric acid, and then electrolytic refining is performed using the resulting leachate having a pH of 1.0 or less and an Sn concentration of 200 g/L or less as an electrolyte.
9) The method for producing tin according to 8), characterized in that the electrolysis is performed at an Sn concentration of 30 to 180 g/L.
10) The method for producing tin according to 8) or 9), characterized in that the raw material tin, in which the amount of lead isotope 210 Pb is 30 Bq/kg or less, is used.
Since recent semiconductor devices are highly densified and of low operation voltage and cell capacity, there is an increasing risk of soft errors caused by the influence of α rays emitted from materials in the vicinity of semiconductor chips. However, the present invention has an excellent effect of providing tin and a tin alloy suitable for materials with low α rays. The occurrence of soft errors in semiconductor devices caused by the influence of α rays can be thereby significantly reduced.
BRIEF DESCRIPTION OF DRAWINGS
FIG. 1 This shows the disintegration chain of uranium (U) disintegrating into 206 Pb (uranium-radium disintegration series).
FIG. 2 This shows the amounts of α rays emitted during the reconstruction of the disintegration chain of 210 Pb→ 210 Bi→ 210 Po→ 206 Pb in a state where there is almost no polonium isotope 210 Po.
FIG. 3 This shows the relationship between the Pb content and the α dose in Sn.
DETAILED DESCRIPTION
There are many radioactive elements that generate α rays; however, most of them have very long or very short half-lives, and therefore do not actually cause problems. Actual problems are α (alpha) rays generated during the disintegration of polonium isotope 210 Po to lead isotope 206 Pb in the U disintegration chain (see FIG. 1 ).
As Pb-free solder materials for semiconductors, Sn—Ag—Cu, Sn—Ag, Sn—Cu, Sn—Zn, etc., have been developed, and there is a demand for low α tin materials. However, it is very difficult to completely remove trace lead contained in tin. Tin materials for semiconductors generally contain lead at a level of 10 ppm or more.
As described above, Po is highly sublimable and sublimates upon heating in the production process, such as melting and casting process. When polonium isotope 210 Po is removed during the production process, it is considered that disintegration of polonium isotope 210 Po to lead isotope 206 Pb does not occur, and α rays are not generated (see the “U disintegration chain” of FIG. 1 ).
However, in a state where there is almost no polonium isotope 210 Po, disintegration of 210 Pb→ 210 Bi→ 210 Po→ 206 Pb occurs. It was also found that about 27 months (a little more than two years) were required for the disintegration chain to be brought into a state of equilibrium (see FIG. 2 ).
More specifically, when the material contains lead isotope 210 Pb (half-life: 22 years), disintegration of 210 Pb→ 210 Bi (half-life: 5 days)→ 210 Po (half-life: 138 days) ( FIG. 1 ) proceeds over time, and the disintegration chain is reconstructed to produce 210 Po. Thus, α rays are generated by the disintegration of polonium isotope 210 Po to lead isotope 206 Pb.
For this reason, the problem cannot be solved even if the α dose is low immediately after the production of products. The α dose gradually increases over time, causing a problem of increasing the risk of developing soft errors. The aforementioned period of 27 months (a little more than two years) is not short at all.
The problem that the α dose gradually increases over time in spite of the low α dose immediately after the production of products is attributable to the fact that the material contains lead isotope 210 Pb of the U disintegration chain shown in FIG. 1 . It can be said that the above problem cannot be solved unless the content of lead isotope 210 Pb is reduced as much as possible.
FIG. 3 shows the relationship between the Pb content and the α dose. It was found that the straight line shown in FIG. 3 shifted up and down depending on the proportion of lead isotopes 214 Pb, 210 Pb, 209 Pb, 208 Pb, 207 Pb, 206 Pb, and 204 Pb, and that the line shifted upwards as the proportion of lead isotope 210 Pb became high. That is, when the amount of lead isotope 210 Pb exceeds 30 Bq/kg, the straight line shown in FIG. 3 moves upwards.
(Analytical Method of 210 Pb and Minimum Determination Limit)
An analysis sample is dissolved in an acid mixture (nitric acid and hydrochloric acid), and then lead and a calcium carrier are added. A hydroxide precipitate is formed by using an ammonia solution, and tin is removed. An ammonia solution and sodium carbonate are placed in the supernatant to form a carbonate precipitate. The precipitate is dissolved in hydrochloric acid, and passed through an Sr resin column. Nitric acid is added to the eluate to form a sulfate precipitate, and the sulfate precipitate is mounted to obtain a measurement sample. The measurement sample is covered with an aluminum plate (27 mg/cm 2 ), and is allowed to stand for two weeks or more. Thereafter, β (beta) rays of 210 Bi produced from 210 Pb are measured for 6,000 seconds by a low-background β-ray measuring device. The net counting rate of the measurement sample is determined, and correction of counting efficiency, chemical recovery rate, etc., is performed, thereby calculating the radioactive concentration of 210 Pb. The measuring devices used were low-background β-ray measuring devices LBC-471Q and LBC-4201 (produced by Aloka Co., Ltd.). The minimum detection limit of the radioactive concentration of 210 Pb is set as “the minimum radioactive value that can be reliably detected” for the nuclide targeted for analysis when analytical and measuring conditions (the amount of measurement sample, chemical recovery rate, measurement time, counting efficiency, etc.) are determined.
From the above, it is important to reduce the proportion of lead isotope 210 Pb in tin. Since the reduction of Pb to 0.1 ppm or less consequently results in the reduction of lead isotope 210 Pb, the α dose does not increase over time.
Furthermore, the lower abundance ratio of lead isotope 206 Pb implies that the ratio of U disintegration chain shown in FIG. 1 is relatively low. It is considered that lead isotope 210 Pb belonging to this system also decreases.
Thereby, the melted and cast tin can achieve an α (alpha) dose of less than 0.0005 cph/cm 2 . This level of a dose forms the basis of the present invention. None of the prior art documents suggests or indicates that the above level of α dose is achieved with such recognition. Specifically, the present invention provides a tin metal giving an α-dose of less than 0.0005 cph/cm 2 measured at an elapsed time of one week, three weeks, one month, two months, six months, or thirty months after the melting and casting, the time elapse of thirty months being longer than a time elapse of 27 months which is needed for the disintegration chain of 210 Pb→ 210 Bi→ 210 Po→ 206 Pb to reach an equilibrium state starting from a state containing 210 Po isotope with α-ray radiation.
Additionally, the present invention can make the difference between the measured α dose of a sample of the melted and cast tin and the α dose of the sample after five months to be less than 0.0003 cph/cm 2 . To reduce the above α dose, the abundance ratio of lead isotope 206 Pb is desirably less than 25% in the raw material tin. The abundance ratio of lead isotope 206 Pb as used herein refers to the proportion of 206 Pb among four stable lead isotopes 208 Pb, 207 Pb, 206 Pb, and 204 Pb.
In this case, the initial (first) measurement of α dose of a tin sample does not only refer to the measurement of α dose of a tin sample immediately after melting and casting. More specifically, the difference between the measured α dose, regardless of when the α dose of the tin sample is measured, and the α dose measured five months later is less than 0.0003 cph/cm 2 . Needless to say, it will be easily understood that it is not denied that the initial measurement of the α dose includes the measurement of the α dose of the tin sample immediately after melting and casting.
Furthermore, the measurement of α dose may require attention to α rays emitted from the α-ray measuring device (equipment) (hereafter, the term “background (BG) α rays” is used, as necessary). The above α dose in the present invention is a substantial amount of α rays excluding α rays emitted from the α-ray measuring device. The term “α dose” described in this specification is used in this sense.
While the above describes the α dose generated from tin, tin-containing alloys are also strongly affected by the α dose. The influence of the α dose may be relieved by components (other than tin) that have a less α dose or hardly produce α rays. However, in the case of a tin alloy comprising at least 40% or more of tin in the alloy contents, it is desirable to use the tin of the present invention, which has a low α dose.
Generally, refining of tin is carried out by a distillation method or an electrolytic method. In the distillation method, however, it is necessary to repeat distillation over and over. Further, when there is an azeotrope, it is difficult to perform isolation and refining, and lead cannot be reduced to a level of 1 ppm or less.
Moreover, the electrolytic method uses an electrolyte prepared by mixing hexafluorosilicate and acid, and adding additives, such as glue, thereto. However, it is difficult to separate tin and lead because their normal electrode potentials are very close to each other (tin: −0.14 V, lead: −0.13 V). Further, the hexafluorosilicate, glue, and other additives may cause lead contamination, and there is a limitation to reduction of lead only to a level of several 10 ppm.
The present invention allows removal of lead to a level of 0.1 ppm by controlling the pH (pH range of strong acid) and the tin concentration in an electrolyte comprising only acid and being free from hexafluorosilicate and additives.
The high-purity tin of the present invention obtained in this manner has an excellent effect of significantly reducing the occurrence of soft errors in the semiconductor device caused by the influence of α rays.
When tin is produced by the above electrolysis, the Sn concentration of the electrolyte is desirably 30 to 200 g/L. When the Sn concentration is less than 30 g/L, the impurity concentration becomes high; whereas when the Sn concentration is higher than 200 g/L, Sn oxide tends to precipitate. Therefore, the Sn concentration is desirably within the above-mentioned range. The upper limit of the Sn concentration is more preferably 180 g/L or less. It is further desirable to use raw material tin in which the amount of lead isotope 210 Pb is 30 Bq/kg or less. Although raw material tin containing lead isotope 210 Pb in an amount more than this range can also be used, it is desirable to enhance the refining effect to reduce the amount of lead isotope 210 Pb as much as possible.
EXAMPLES
Next, Examples of the present invention are described. The following Examples are merely illustrative, and the present invention is not limited thereto. That is, embodiments other than the Examples or modifications are all included within the scope of the technical idea of the present invention.
The raw material tins shown in Table 1 were used in the following Examples and Comparative Examples. Table 1 shows the type of raw material tin and the amount of lead isotope 210 Pb contained in each of the raw materials A to E (unit: Bq/kg).
TABLE 1
Amount of Lead Isotope 210 Pb
Type of Raw Material Tin
(Bq/kg)
Raw Material A
14
Raw Material B
15
Raw Material C
48 ± 6.2
Raw Material D
60 ± 7.2
Raw Material E
24
Example 1
Raw material tin with a purity level of 3N was leached in hydrochloric acid (or sulfuric acid), and the resulting leachate having a pH of 1.0 and an Sn concentration of 80 g/L was used as an electrolyte. Using a tin plate obtained by casting raw material tin as the anode, and a titanium plate as the cathode, electrolysis was carried out under conditions where the electrolysis temperature was 30° C., and the current density was 7 A/dm 2 .
When the thickness of the tin electrodeposited on the cathode reached about 2 mm, the electrolysis was halted, and the cathode was taken out from the electrolytic cell. The electrodeposited tin was collected by being removed from the cathode. After the collection, the cathode was returned to the electrolytic cell, and the electrolysis was started again. This operation was repeated. The collected electrodeposited tin was washed and dried, and melted and cast at a temperature of 260° C. to obtain a tin ingot.
The tin ingot was subject to rolling to a thickness of about 1.5 mm, and cut into a square (310 mm×310 mm). Its surface area was 961 cm 2 . This was used as a sample for measurement of α rays.
In this sample, the Pb content was 0.06 ppm, the U content was less than 5 ppb, and the Th content was less than 5 ppb.
Moreover, the amount of unstable lead isotope 210 Pb was 14 Bq/kg in the raw material tin (raw material A) used herein. The total amount of four stable lead isotopes was 1.81 ppm, and the abundance ratio of stable lead isotope 206 Pb was 24.86%. The abundance ratio of lead isotope 206 Pb as used herein indicates that the proportion of 206 Pb among four lead isotopes 208 Pb, 207 Pb, 206 Pb, and 204 Pb. The same applies to the following Examples.
The α-ray measuring device used was an ORDELA Model 8600 A-LB gas flow proportional counter. The gases used were 90% argon and 10% methane. The measurement time for both the background and sample was 104 hours. The initial four hours were regarded as the time required for purging the measurement chamber, and the data between 5 to 104 hours after the start of measurement was used for the calculation of the α dose.
As a result of measuring the α dose of the above sample one week, three weeks, one month, two months, and six months after melting and casting, and thirty months being beyond 27 months in which the disintegration chain of 210 Pb→ 210 Bi→ 210 Po→ 206 Pb was brought into a state of equilibrium when there was no polonium isotope 210 Po producing α rays by the disintegration to lead isotope 206 Pb; the α dose was at a maximum of 0.0003 cph/cm 2 , which satisfied the requirements of the present invention.
Moreover, when α dose changes of the same sample in five months (between the first month and the sixth month) were observed, the difference in α dose of the sample was 0.0001 cph/cm 2 , which satisfied the requirements of the present invention. As described above, the measured α dose was a substantial amount of α rays excluding α rays emitted from the α-ray measuring device. The same applies to the following Examples.
In this Example, the leachate having a pH of 1.0 and an Sn concentration of 80 g/L was used as an electrolyte; however, almost similar results were obtained when electrolytic refining was performed under different electrolyte conditions (Sn concentration) using a leachate having a pH of 1.0 and an Sn concentration of 30 g/L or a leachate having a pH of 1.0 and an Sn concentration of 180 g/L.
Example 2
Raw material tin with a purity level of 3N was leached in hydrochloric acid (or sulfuric acid), and the resulting leachate having a pH of 1.0 and an Sn concentration of 80 g/L was used as an electrolyte. Using a tin plate obtained by casting raw material tin as the anode, and a titanium plate as the cathode, electrolysis was carried out under conditions where the electrolysis temperature was 30° C., and the current density was 1 A/dm 2 .
When the thickness of the tin electrodeposited on the cathode reached about 2 mm, the electrolysis was halted, and the cathode was taken out from the electrolytic cell. The electrodeposited tin was collected by being removed from the cathode. After the collection, the cathode was returned to the electrolytic cell, and the electrolysis was started again. This operation was repeated. The collected electrodeposited tin was washed and dried, and melted and cast at a temperature of 260° C. to obtain a tin ingot.
The tin ingot was subject to rolling to a thickness of about 1.5 mm, and cut into a square (310 mm×310 mm). Its surface area was 961 cm 2 . This was used as a sample for measurement of α rays.
In this sample, the Pb content was 0.07 ppm, the U content was less than 5 ppb, and the Th content was less than 5 ppb.
Moreover, the amount of unstable lead isotope 210 Pb was 14 Bq/kg in the raw material tin (raw material A, same as the raw material of Example 1) used herein. The total amount of four stable lead isotopes was 1.81 ppm, and the abundance ratio of stable lead isotope 206 Pb was 24.86%.
As a result of measuring the α dose of the above sample one week, three weeks, one month, two months, and six months after melting and casting, and thirty months being beyond 27 months in which the disintegration chain of 210 Pb→ 210 Bi→ 210 Po→ 206 Pb was brought into a state of equilibrium when there was no polonium isotope 210 Po producing α rays by the disintegration to lead isotope 206 Pb, the α dose was at a maximum of 0.0003 cph/cm 2 , which satisfied the requirements of the present invention.
Moreover, when α dose changes of the same sample in five months (between the first month and the sixth month) were observed, the difference in α dose of the sample was 0.0001 cph/cm 2 , which satisfied the requirements of the present invention.
In this Example, the leachate having a pH of 1.0 and an Sn concentration of 80 g/L was used as an electrolyte; however, almost similar results were obtained when electrolytic refining was performed under different electrolyte conditions (Sn concentration) using a leachate having a pH of 1.0 and an Sn concentration of 30 g/L or a leachate having a pH of 1.0 and an Sn concentration of 180 g/L.
Example 3
Raw material tin with a purity level of 3N was leached in hydrochloric acid (or sulfuric acid), and the resulting leachate having a pH of 1.0 and an Sn concentration of 80 g/L was used as an electrolyte.
Using a tin plate obtained by casting raw material tin as the anode, and a titanium plate as the cathode, electrolysis was carried out under conditions where the electrolysis temperature was 30° C., and the current density was 1 A/dm 2 .
When the thickness of the tin electrodeposited on the cathode reached about 2 mm, the electrolysis was halted, and the cathode was taken out from the electrolytic cell. The electrodeposited tin was collected by being removed from the cathode. After the collection, the cathode was returned to the electrolytic cell, and the electrolysis was started again. This operation was repeated. The collected electrodeposited tin was washed and dried, and melted and cast at a temperature of 260° C. to obtain a tin ingot.
The tin ingot was subject to rolling to a thickness of about 1.5 mm, and cut into a square (310 mm×310 mm). Its surface area was 961 cm 2 . This was used as a sample for measurement of α rays.
In this sample, the Pb content was 0.05 ppm, the U content was less than 5 ppb, and the Th content was less than 5 ppb.
Moreover, the amount of unstable lead isotope 210 Pb was 15 Bq/kg in the raw material tin (raw material B) used herein. The total amount of four stable lead isotopes was 3.8 ppm, and the abundance ratio of stable lead isotope 206 Pb was 24.74%.
As a result of measuring the α dose of the above sample one week, three weeks, one month, two months, and six months after melting and casting, and thirty months being beyond 27 months in which the disintegration chain of 210 Pb→ 210 Bi→ 210 Po→ 206 Pb was brought into a state of equilibrium when there was no polonium isotope 210 Po producing α rays by the disintegration to lead isotope 206 Pb; the α dose was at a maximum of 0.0002 cph/cm 2 , which satisfied the requirements of the present invention.
Moreover, when α dose changes of the same sample in five months (between the first month and the sixth month) were observed, the difference in α dose of the sample was 0.0001 cph/cm 2 , which satisfied the requirements of the present invention.
In this Example, the leachate having a pH of 1.0 and an Sn concentration of 80 g/L was used as an electrolyte; however, almost similar results were obtained when electrolytic refining was performed under different electrolyte conditions (Sn concentration) using a leachate having a pH of 1.0 and an Sn concentration of 30 g/L or a leachate having a pH of 1.0 and an Sn concentration of 180 g/L.
Example 4
Raw material tin with a purity level of 3N was leached in hydrochloric acid (or sulfuric acid), and the resulting leachate having a pH of 1.0 and an Sn concentration of 80 g/L was used as an electrolyte. Using a tin plate obtained by casting raw material tin as the anode, and a titanium plate as the cathode, electrolysis was carried out twice under conditions where the electrolysis temperature was 30° C., and the current density was 7 A/dm 2 . That is, this process is to perform electrolysis again (second electrolysis) using, as the anode, a tin plate obtained by subjecting the electrodeposited tin, which was collected by the first electrolysis, to melting and casting.
In the above electrolysis process, when the thickness of the tin electrodeposited on the cathode reached about 2 mm, the electrolysis was halted, and the cathode was taken out from the electrolytic cell. The electrodeposited tin was collected by being removed from the cathode. After the collection, the cathode was returned to the electrolytic cell, and the electrolysis was started again. This operation was repeated. The collected electrodeposited tin was washed and dried, and melted and cast at a temperature of 260° C. to obtain a tin ingot.
The tin ingot was subject to rolling to a thickness of about 1.5 mm, and cut into a square (310 mm×310 mm). Its surface area was 961 cm 2 . This was used as a sample for measurement of α rays.
In this sample, the Pb content was 0.06 ppm, the U content was less than 5 ppb, and the Th content was less than 5 ppb.
Moreover, the amount of unstable lead isotope 210 Pb was 48±6.2 Bq/kg in the raw material tin (raw material C) used herein. The total amount of four stable lead isotopes was 11.55 ppm, and the abundance ratio of stable lead isotope 206 Pb was 25.97%.
As a result of measuring the α dose of the above sample one week, three weeks, one month, two months, and six months after melting and casting, and thirty months being beyond 27 months in which the disintegration chain of 210 Pb→ 210 Bi→ 210 Po→ 206 Pb was brought into a state of equilibrium when there was no polonium isotope 210 Po producing α rays by the disintegration to lead isotope 206 Pb; the α dose was at a maximum of less than 0.0005 cph/cm 2 , which satisfied the requirements of the present invention.
Moreover, when α dose changes of the same sample in five months (between the first month and the sixth month) were observed, the difference in α dose of the sample was 0.0002 cph/cm 2 , which satisfied the requirements of the present invention. In this Example, the leachate having a pH of 1.0 and an Sn concentration of 80 g/L was used as an electrolyte; however, almost similar results were obtained when electrolytic refining was performed under different electrolyte conditions (Sn concentration) using a leachate having a pH of 1.0 and an Sn concentration of 30 g/L or a leachate having a pH of 1.0 and an Sn concentration of 180 g/L.
Example 5
Raw material tin with a purity level of 3N was leached in hydrochloric acid (or sulfuric acid), and the resulting leachate having a pH of 1.0 and an Sn concentration of 80 g/L was used as an electrolyte. Using a tin plate obtained by casting raw material tin as the anode, and a titanium plate as the cathode, electrolysis was carried out under conditions where the electrolysis temperature was 30° C., and the current density was 7 A/dm 2 .
When the thickness of the tin electrodeposited on the cathode reached about 2 mm, the electrolysis was halted, and the cathode was taken out from the electrolytic cell. The electrodeposited tin was collected by being removed from the cathode. After the collection, the cathode was returned to the electrolytic cell, and the electrolysis was started again. This operation was repeated. The collected electrodeposited tin was washed and dried, and melted and cast at a temperature of 260° C. to obtain a tin ingot.
The tin ingot was subject to rolling to a thickness of about 1.5 mm, and cut into a square (310 mm×310 mm). Its surface area was 961 cm 2 . This was used as a sample for measurement of α rays.
In this sample, the Pb content was 0.06 ppm, the U content was less than 5 ppb, and the Th content was less than 5 ppb.
Moreover, the amount of unstable lead isotope 210 Pb was 24 Bq/kg in the raw material tin (raw material E) used herein. The total amount of four stable lead isotopes was 4.5 ppm, and the abundance ratio of stable lead isotope 266 Pb was 22.22%.
As a result of measuring the α dose of the above sample one week, three weeks, one month, two months, and six months after melting and casting, and thirty months being beyond 27 months in which the disintegration chain of 210 Pb→ 210 Bi→ 210 Po→ 206 Pb was brought into a state of equilibrium when there was no polonium isotope 210 Po producing α rays by the disintegration to lead isotope 206 Pb; the α dose was at a maximum of 0.0005 cph/cm 2 , which satisfied the requirements of the present invention.
Moreover, when α dose changes of the same sample in five months (between the first month and the sixth month) were observed, the difference in α dose of the sample was 0.0002 cph/cm 2 , which satisfied the requirements of the present invention.
In this Example, the leachate having a pH of 1.0 and an Sn concentration of 80 g/L was used as an electrolyte; however, almost similar results were obtained when electrolytic refining was performed under different electrolyte conditions (Sn concentration) using a leachate having a pH of 1.0 and an Sn concentration of 30 g/L or a leachate having a pH of 1.0 and an Sn concentration of 180 g/L.
Comparative Example 1
Raw material tin with a purity level of 3N was leached in hydrochloric acid (or sulfuric acid), and the resulting leachate having a pH of 1.0 and an Sn concentration of 80 g/L was used as an electrolyte.
Using a tin plate obtained by casting raw material tin as the anode, and a titanium plate as the cathode, electrolysis was carried out under conditions where the electrolysis temperature was 30° C., and the current density was 7 A/dm 2 .
When the thickness of the tin electrodeposited on the cathode reached about 2 mm, the electrolysis was halted, and the cathode was taken out from the electrolytic cell. The electrodeposited tin was collected by being removed from the cathode. After the collection, the cathode was returned to the electrolytic cell, and the electrolysis was started again. This operation was repeated. The collected electrodeposited tin was washed and dried, and melted and cast at a temperature of 260° C. to obtain a tin ingot.
The tin ingot was subject to rolling to a thickness of about 1.5 mm, and cut into a square (310 mm×310 mm). Its surface area was 961 cm 2 . This was used as a sample for measurement of α rays.
In this sample, the Pb content was 0.07 ppm, the U content was less than 5 ppb, and the Th content was less than 5 ppb.
Moreover, the amount of unstable lead isotope 210 Pb was 60±7.2 Bq/kg in the raw material tin (raw material D) used herein. The total amount of four stable lead isotopes was 12.77 ppm, and the abundance ratio of stable lead isotope 206 Pb was 25.06%.
The α dose of the above sample three weeks after melting and casting was the same level as the background (BG) α dose. However, the α dose six months after melting and casting clearly increased, and the α dose of the sample (the difference from the background α dose) was 0.02 cph/cm 2 , which did not satisfy the requirements of the present invention.
The reason for this is considered to be that: the α dose was temporarily reduced because of sublimation of Po during the melting and casting process; but the purification effect was not sufficient, the Pb content was high, and the 210 Pb content was consequently also high; and therefore the disintegration chain ( 210 Pb→ 210 Bi→ 210 Po→ 206 Pb) was reconstructed to increase the α dose.
Moreover, when α dose changes of the same sample in five months (between the first month and the sixth month) were observed, the difference in α dose of the sample was 0.007 cph/cm 2 , which did not satisfy the requirements of the present invention.
Comparative Example 2
Raw material tin with a purity level of 3N was leached in hydrochloric acid (or sulfuric acid), and the resulting leachate having a pH of 1.0 and an Sn concentration of 80 g/L was used as an electrolyte.
Using a tin plate obtained by casting raw material tin as the anode, and a titanium plate as the cathode, electrolysis was carried out under conditions where the electrolysis temperature was 30° C., and the current density was 7 A/dm 2 .
When the thickness of the tin electrodeposited on the cathode reached about 2 mm, the electrolysis was halted, and the cathode was taken out from the electrolytic cell. The electrodeposited tin was collected by being removed from the cathode. After the collection, the cathode was returned to the electrolytic cell, and the electrolysis was started again. This operation was repeated. The collected electrodeposited tin was washed and dried, and melted and cast at a temperature of 260° C. to obtain a tin ingot.
The tin ingot was subject to rolling to a thickness of about 1.5 mm, and cut into a square (310 mm×310 mm). Its surface area was 961 cm 2 . This was used as a sample for measurement of α rays.
In this sample, the Pb content was 0.09 ppm, the U content was less than 5 ppb, and the Th content was less than 5 ppb.
Moreover, the amount of unstable lead isotope 210 Pb was 48±6.2 Bq/kg in the raw material tin (raw material C, same as the raw material of Example 4) used herein. The total amount of four stable lead isotopes was 11.55 ppm, and the abundance ratio of stable lead isotope 206 Pb was 25.97%.
The α dose of the above sample three weeks after melting and casting was the same level as the background (BG) α dose. However, the α dose six months after melting and casting clearly increased, and the α dose of the sample (the difference from the background α dose) was 0.01 cph/cm 2 , which did not satisfy the requirements of the present invention.
The reason for this is considered to be that: the α dose was temporarily reduced because of sublimation of Po during the melting and casting process; but the purification effect was not sufficient, the Pb content was high, and the 210 Pb content was consequently also high; and therefore the disintegration chain ( 210 Pb→ 210 Bi→ 210 Po→ 206 Pb) was reconstructed to increase the α dose.
Moreover, when α dose changes of the same sample in five months (between the first month and the sixth month) were observed, the difference in α dose of the sample was 0.007 cph/cm 2 , which did not satisfy the requirements of the present invention.
Comparative Example 3
Tin containing 4 ppm of Pb was melted and cast at a temperature of 260° C. to obtain a tin ingot. The tin ingot was subject to rolling to a thickness of about 1.5 mm, and cut into a square (310 mm×310 mm). Its surface area was 961 cm 2 . This was used as a sample for measurement of α rays.
In this sample, the Pb content was 4 ppm, the U content was less than 5 ppb, and the Th content was less than 5 ppb.
Moreover, in the raw material tin (material obtained by mixing the raw material B used in Example 3 and the tin produced in Example 3) used herein, the total amount of four stable lead isotopes was 3.9 ppm, and the abundance ratio of stable lead isotope 206 Pb was 25%.
The α dose of the above sample three weeks after melting and casting was the same level as the background (BG) α dose. However, the α dose six months after melting and casting clearly increased, and the α dose of the sample (the difference from the background α dose) was 0.0008 cph/cm 2 , which did not satisfy the requirements of the present invention.
The reason for this is considered to be that: the α dose was temporarily reduced because of sublimation of Po during the melting and casting process; but the purification effect was not sufficient, the Pb content was high, and the 210 Pb content was consequently also high; and therefore the disintegration chain ( 210 Pb→ 210 Bi→ 210 Po→ 206 Pb) was reconstructed to increase the α dose.
Moreover, when α dose changes of the same sample in five months (between the first month and the sixth month) were observed, the difference in α dose of the sample was 0.0004 cph/cm 2 , which also did not satisfy the requirements of the present invention.
Comparative Example 4
Raw material tin with a purity level of 3N was leached in hydrochloric acid (or sulfuric acid), and mixed with hexafluorosilicate and acid. The resulting leachate having an Sn concentration of 50 g/L was used as an electrolyte.
Using a tin plate obtained by casting raw material tin as the anode, and a titanium plate as the cathode, electrolysis was carried out under conditions where the electrolysis temperature was 20° C., and the current density was 1 A/dm 2 .
When the thickness of the tin electrodeposited on the cathode reached about 2 mm, the electrolysis was halted, and the cathode was taken out from the electrolytic cell. The electrodeposited tin was collected by being removed from the cathode. After the collection, the cathode was returned to the electrolytic cell, and the electrolysis was started again. This operation was repeated.
The collected electrodeposited tin was washed and dried, and melted and cast at a temperature of 260° C. to obtain a tin ingot. The tin ingot was subject to rolling to a thickness of about 1.5 mm, and cut into a square (310 mm×310 mm). Its surface area was 961 cm 2 . This was used as a sample for measurement of α rays.
In this sample, the Pb content was 0.7 ppm, the U content was less than 5 ppb, and the Th content was less than 5 ppb.
Moreover, the amount of unstable lead isotope 210 Pb was 14 Bq/kg in the raw material tin (raw material A, same as the raw material of Example 1) used herein. The total amount of four stable lead isotopes was 1.81 ppm, and the abundance ratio of stable lead isotope 206 Pb was 24.86%.
The α dose of the above sample three weeks after melting and casting was the same level as the background (BG) α dose. However, the α dose six months after melting and casting clearly increased, and the α dose of the sample (the difference from the background α dose) was 0.0003 cph/cm 2 , which did not satisfy the requirements of the present invention.
The reason for this is considered to be that: the α dose was temporarily reduced because of sublimation of Po during the melting and casting process; but the purification effect was not sufficient, the Pb content was high, and the 210 Pb content was consequently also high; and therefore the disintegration chain ( 210 Pb→ 210 Bi→ 210 Po→ 206 Pb)) was reconstructed to increase the α dose.
Moreover, when α dose changes of the same sample in five months (between the first month and the sixth month) were observed, the difference in α dose of the sample was 0.0003 cph/cm 2 , which also did not satisfy the requirements of the present invention.
Example 5
Tin Alloy Comprising 0.5% Cu, 3% Ag, and Balance Sn
The tin produced in Example 1 was prepared. The additive elements of the tin alloy of this Example were 6N—Ag and 6N—Cu, which were prepared by highly purifying the commercially available silver and copper by electrolysis. These elements were added to the above tin, and melted and cast at 260° C., thereby producing an Sn—Cu—Ag alloy ingot comprising 0.5% Cu, 3% Ag, and the balance Sn.
The tin ingot was subject to rolling to a thickness of about 1.5 mm, and cut into a square (310 mm×310 mm). Its surface area was 961 cm 2 . This was used as a sample for measurement of α rays.
In this sample, the Pb content was 0.06 ppm, the U content was less than 5 ppb, and the Th content was less than 5 ppb.
As a result of measuring the α dose of the above sample one week, three weeks, one month, two months, and six months after melting and casting, and thirty months being beyond 27 months in which the disintegration chain of 210 Pb→ 210 Bi→ 210 Po→ 206 Pb was brought into a state of equilibrium when there was no polonium isotope 210 Po producing α rays by the disintegration to lead isotope 206 Pb; the α dose was at a maximum of 0.0003 cph/cm 2 , which satisfied the requirements of the present invention.
Moreover, when α dose changes of the same sample in five months (between the first month and the sixth month) were observed, the difference in α dose of the sample was 0.0001 cph/cm 2 , which satisfied the requirements of the present invention.
Example 6
Tin Alloy Comprising 3.5% Ag and Balance Sn
The tin produced in Example 1 was prepared. The additive element of the tin alloy of this Example was high-purity silver, which was prepared by dissolving the commercially available Ag with nitric acid, adding HCl thereto to precipitate AgCl, and further subjecting the precipitated AgCl to hydrogen reduction, thereby obtaining high-purity Ag (5N—Ag). This element was added to the above tin, and melted and cast at 260° C., thereby producing an Sn—Ag alloy ingot comprising 3.5% Ag and the balance Sn.
The tin ingot was subject to rolling to a thickness of about 1.5 mm, and cut into a square (310 mm×310 mm). Its surface area was 961 cm 2 . This was used as a sample for measurement of α rays.
In this sample, the Pb content was 0.06 ppm, the U content was less than 5 ppb, and the Th content was less than 5 ppb.
As a result of measuring the α dose of the above sample one week, three weeks, one month, two months, and six months after melting and casting, and thirty months being beyond 27 months in which the disintegration chain of 210 Pb→ 210 Bi→ 210 Po→ 206 Pb was brought into a state of equilibrium when there was no polonium isotope 210 Po producing α rays by the disintegration to lead isotope 206 Pb; the α dose was at a maximum of 0.0003 cph/cm 2 , which satisfied the requirements of the present invention. Moreover, when α dose changes of the same sample in five months (between the first month and the sixth month) were observed, the difference in α dose of the sample was 0.0001 cph/cm 2 , which satisfied the requirements of the present invention.
Example 7
Tin Alloy Comprising 9% Zn and Balance Sn
The tin produced in Example 1 was prepared. The additive element of the tin alloy of this Example was 6N—Zn, which was prepared by highly purifying the commercially available zinc by electrolysis. This element was added to the above tin, and melted and cast at 240° C., thereby producing an Sn—Zn alloy ingot comprising 9% Zn and the balance Sn. The tin ingot was subject to rolling to a thickness of about 1.5 mm, and cut into a square (310 mm×310 mm). Its surface area was 961 cm 2 . This was used as a sample for measurement of α rays. In this sample, the Pb content was 0.06 ppm, the U content was less than 5 ppb, and the Th content was less than 5 ppb.
As a result of measuring the α dose of the above sample one week, three weeks, one month, two months, and six months after melting and casting, and thirty months being beyond 27 months in which the disintegration chain of 210 Pb→ 210 Bi→ 210 Po→ 206 Pb was brought into a state of equilibrium when there was no polonium isotope 210 Po producing α rays by the disintegration to lead isotope 266 Pb, the α dose was at a maximum of 0.0003 cph/cm 2 , which satisfied the requirements of the present invention. Moreover, when α dose changes of the same sample in five months (between the first month and the sixth month) were observed, the difference in α dose of the sample was 0.0001 cph/cm 2 , which satisfied the requirements of the present invention.
Comparative Example 5
Tin Alloy Comprising 0.5% Cu, 3% Ag, and Balance Sn
The tin produced in Example 1 was prepared. The additive elements of the tin alloy of this Comparative Example were the commercially available 3N-level silver and copper. These elements were added to the above tin, and melted and cast at 260° C., thereby producing an Sn—Cu—Ag alloy ingot comprising 0.5% Cu, 3% Ag, and the balance Sn. In this sample, the Pb content was 7.1 ppm, the U content was 10 ppb, and the Th content was 10 ppb.
The α dose of the above sample three weeks after melting and casting was the same level as the background α dose. However, the α dose six months after melting and casting clearly increased, and the α dose of the sample (the difference from the background α dose) was 0.1 cph/cm 2 , which did not satisfy the requirements of the present invention.
Moreover, when α dose changes of the same sample in five months (between the first month and the sixth month) were observed, the difference in α dose of the sample was 0.005 cph/cm 2 , which also did not satisfy the requirements of the present invention.
The reason for this is considered to be that: the α dose was temporarily reduced because of sublimation of Po during the melting and casting process; but the Pb content was high, and the 210 Pb content was consequently also high; and therefore the disintegration chain ( 210 Pb→ 210 Bi→ 210 Po→ 206 Pb) was reconstructed to increase the α dose.
Comparative Example 6
Tin Alloy Comprising 3.5% Ag and Balance Sn
The tin produced in Example 1 was prepared. The additive element of the tin alloy of this Comparative Example was the commercially available 3N-level Ag. This element was added to the above tin, and melted and cast at 260° C., thereby producing an Sn—Ag alloy ingot comprising 3.5% Ag and the balance Sn.
In this sample, the Pb content was 5.3 ppm, the U content was 7 ppb, and the Th content was 6 ppb.
The α dose of the above sample three weeks after melting and casting was the same level as the background α dose. However, the α dose six months after melting and casting clearly increased, and the α dose of the sample (the difference from the background α dose) was 0.03 cph/cm 2 , which did not satisfy the requirements of the present invention.
Moreover, when α dose changes of the same sample in five months (between the first month and the sixth month) were observed, the difference in α dose of the sample was 0.002 cph/cm 2 , which also did not satisfy the requirements of the present invention.
The reason for this is considered to be that: the α dose was temporarily reduced because of sublimation of Po during the melting and casting process; but the Pb content was high, and the 210 Pb content was consequently also high; and therefore the disintegration chain ( 210 Pb→ 210 Bi→ 210 Po→ 206 Pb) was reconstructed to increase the α dose.
Comparative Example 7
Tin Alloy Comprising 9% Zn and Balance Sn
The tin produced in Example 1 was prepared. The additive element of the tin alloy of this Comparative Example was the commercially available 3N-level zinc. This element was added to the above tin, and melted and cast at 240° C., thereby producing an Sn—Zn alloy ingot comprising 9% Zn and the balance Sn.
In this sample, the Pb content was 15.1 ppm, the U content was 12 ppb, and the Th content was 10 ppb.
The α dose of the above sample three weeks after melting and casting was the same level as the background α dose; however, the α dose six months after melting and casting clearly increased. The α dose of the sample (the difference from the background α dose) was 0.5 cph/cm 2 , which did not satisfy the requirements of the present invention. Moreover, when α dose changes of the same sample in five months (between the first month and the sixth month) were observed, the difference in α dose of the sample was 0.01 cph/cm 2 , which also did not satisfy the requirements of the present invention.
The reason for this is considered to be that: the α dose was temporarily reduced because of sublimation of Po during the melting and casting process; but the Pb content was high, and the 210 Pb content was consequently also high; and therefore the disintegration chain ( 210 Pb→ 210 Bi→ 210 Po→ 206 Pb) was reconstructed to increase the α dose.
As described above, since the present invention has an excellent effect of providing tin and a tin alloy suitable for materials with low α rays, the influence of α rays on semiconductor chips can be eliminated as much as possible. Accordingly, the present invention can significantly reduce the occurrence of soft errors in semiconductor devices caused by the influence of α rays, and is thus useful as a material to be used in an area where tin is used as a solder material or the like. | Disclosed is tin characterized in that a sample of the tin after melting and casting has an α dose of less than 0.0005 cph/cm 2 . Since recent semiconductor devices are highly densified and of high capacity, there is an increasing risk of soft errors caused by the influence of α rays emitted from materials in the vicinity of semiconductor chips. In particular, there are strong demands for high purification of solder materials and tin for use in the vicinity of semiconductor devices, and demands for materials with lower α rays. Accordingly, an object of the present invention is to clarify the phenomenon of the generation of α rays in tin and tin alloys, and to obtain high-purity tin, in which the α dose has been reduced, suitable for the required materials, as well as a method for producing the same. | 2 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] None.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH
[0002] Not applicable.
BACKGROUND
[0003] The present disclosure relates to harvesting articulated (jointed) combines and more particularly to improved concaves in the forward tractor or crop processing power unit (PPU).
[0004] Most agricultural combines use a rotary threshing and/or separating system including at least one rotor drivingly rotated about a rotational axis within a rotor housing, the housing having a lower region including a perforated concave spaced radially outwardly of the rotor. The rotor often may have a frusto-conical inlet end having a helical flight or flights therearound for conveying a flow of crop material into the space between the rotor and the housing. The main body of the rotor typically will have an array or layout of threshing elements, most commonly including rasp bars and separating elements, and/or elongated tines, all of which protrude radially outwardly therefrom into the space. The rasp bars and separator bars are configured differently, so as to perform different functions and may not all be present on a given rotor design. The functions of the rasp bars include to cooperate with one or more vanes and guides typically disposed around the upper portion of the inner circumference of the rotor housing, for conveying a mat of the crop material along a generally helical path through the space, while cooperating with the vane or vanes and/or guides, and other aspects of the concave, e.g., bars, perforations and the like of the concave, to break up larger components of the crop material into its constituents, namely larger constituents or elements of crop residue commonly referred to as straw, which includes stalks, stems, cobs and the like, and smaller constituents which comprise the grain and smaller elements of material other than grain (MOG), in the well known manner.
[0005] Rasp bars usually are relatively narrow and generally concentrated nearer the inlet end of the rotor and include a plurality of serrations defining grooves in the threshing element. These grooves are oriented at small acute angles to, or generally aligned with, the direction of rotation of the rotor for raking or combing through the mat of crop material and uncoupling the smaller constituents from the crop material thus allowing the grain to fall through the openings in the concave. Straight separator bars, in contrast, are often longer and generally located nearer to the discharge end of the rotor and include one or more bars with at least one sharp edge extending perpendicular to the direction of rotation to plow the larger components of the crop mat and carry them away from the smaller grain and MOG. The function of typical straight bars is to disrupt the consistent flow that shorter rasp bars establish and, thereby, cause grain to be shaken out of the straw due to that turbulence.
[0006] To minimize damage to the grain it is desirable to separate the grain from the mat of crop material so it can fall through the openings in the concave as far forward in the threshing system as possible. The number and size of openings in the forward portion of the concave is limited, however, and it has been observed that some of the threshed grain travels over additional rasp bars or other threshing surfaces on the rotor prior to falling through an opening of the concave.
[0007] It has also been observed that when the relatively narrow rasp bars engage the mat of crop material, some of the larger portions, particularly ears of corn, will deflect off rather than flowing over the rasp bars. As a result, the grain remains in the threshing system longer, encountering more threshing elements, risking damage to the grain, and increasing the likelihood that the cobs will break.
[0008] Accordingly, what is sought is a threshing system for an agricultural harvester including threshing elements, which overcome at least some of the problems, shortcomings, or disadvantages set forth above.
BRIEF SUMMARY
[0009] Disclosed is a rotor and cage assembly that includes a skeleton of curved spaced-apart side members affixed to laterally extending horizontal (upper and lower) spaced-apart members therebetween and surrounding the rotor. One of the curved spaced-apart side members is terminated with curved fingers. Three concave inserts insert laterally into the skeleton spanning 270° around the rotor. One of the concave inserts carries straight fingers that interlace between the skeleton side member curved fingers. A control assembly of plates having arcuate slots placed at 3 of the pivots of the skeleton assembly, control bars connected to the skeleton pivots, and an actuator connect to the control bars at one end effect arcuate rotation of the control bars resulting in the synchronized rotation of the arcuate slotted plates so that the interlaced straight fingers move closer together or farther apart with the fixed skeleton assembly curved fingers for different types of grain. The interlacing and overlapping concave inserts permit the three sections of 270° degree wrap to expand and contract their combined circumference as the concaves move nearer and farther from the rotor swung diameter. This movement is necessary in order to adjust to various crops and conditions, specifically and intentionally to prevent wide gap spaces between concave inserts especially when the assembly is in its open position. A reasonably identical grate assembly, which may or may not allow adjustment, follows and is adjacent to the concaves skeleton and also surrounds the rotor. Of course, the number off concave inserts could be greater or lesser in number and extend to less or more than 270°. For present purposes, the two different sets of fingers “interlace” both by being laterally offset (side-to-side), but also by being vertically offset (up-and-down). The key for interlaced fingers is that they move closer together and further apart for different types of grains.
[0010] A concaves control assembly for a concaves assembly includes a skeleton for receiving at least two concave inserts end-to-end. At least two concave inserts are housed within the skeleton for threshing grain in concert with a rotor assembly. Rotatable plates have arcuate slots are located where the at least two concave inserts meet and are carried by and are rotatable with skeleton pivot pins. Control bars connect to and are between the skeleton pivot pins. An actuator connects to the control bars at one end of one of the control bars, whereby actuation of the actuator moves the control bars causing arcuate rotation of the arcuate slotted plates for moving the at least two end-to-end concave inserts closer together and farther apart.
[0011] A grates control assembly for a grates assembly includes a skeleton for receiving at least two grate inserts end-to-end. At least two grate inserts insert within the skeleton for separating grain in concert with a rotor assembly. Rotatable plates have arcuate slots and are located where the at least two grate inserts meet and are carried by and rotatable with skeleton pivot pins. Control bars connect to and are located between the skeleton pivot pins. An actuator connects to the control bars at one end of one of the control bars, whereby actuation of the actuator moves the control bars causing arcuate rotation of the arcuate slotted plates for moving the at least two end-to-end grate inserts closer together and farther apart.
[0012] The concaves assembly and grates assembly are placed together with both the concaves control assembly and grates control assembly working in concert to adjust both the concaves assembly and the grates assembly. The actuator of some of the grates inserts may be manual and/or powered.
[0013] These are other features will be described in detail below.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] For a fuller understanding of the nature and advantages of the present method and process, reference should be had to the following detailed description taken in connection with the accompanying drawings, in which:
[0015] FIG. 1 is a side elevation view of an articulated combine having the disclosed grain cart;
[0016] FIG. 2 is an overhead view of the articulated combine of FIG. 1 ;
[0017] FIG. 3 is an isometric view of the articulated combine of FIG. 1 ;
[0018] FIG. 4 is an isometric view of the PPU from its rear;
[0019] FIG. 5 is the isometric view of FIG. 4 with the outer shell or skin removed from the PPU;
[0020] FIG. 6 is a sectional view taken along line 6 - 6 of FIG. 1 ;
[0021] FIG. 7 is an isometric view like that of FIG. 5 of the opposite side of the PPU;
[0022] FIG. 8 is a bottom view of the PPU;
[0023] FIG. 9 is a bottom view of the concaves section of the PPU and includes the twin straw choppers;
[0024] FIG. 10 is a side isometric view of the concaves of FIG. 9 ;
[0025] FIG. 11 is a front isometric view of the concaves of FIG. 8 ;
[0026] FIG. 12 is a side isometric view of the rotor assembly of the concaves;
[0027] FIG. 13 is a bottom isometric view of the concave grates and concaves frame assembly;
[0028] FIG. 14 is a front view of the concaves cage in a closed position with common actuator assembly;
[0029] FIG. 15 is a front view of the concaves cage from FIG. 14 with the common actuator removed;
[0030] FIG. 16 is a front view of the grates (or bonus sieves) cage in an open position with common actuator mechanism;
[0031] FIG. 17 is a front view of the grates (or bonus sieves) cage from FIG. 16 with the common actuator removed;
[0032] FIG. 18 is an isometric view of the concaves sieves assembly in a closed position;
[0033] FIG. 18A is a blowup of the fingers of the concaves sieves assembly of FIG. 18 with the fingers in a closed position consonant with the concaves being in a closed position;
[0034] FIG. 19 is an isometric view of the concaves sieves assembly in an open position;
[0035] FIG. 19A is a blowup of the fingers of the concaves sieves assembly of FIG. 19 with the fingers in an open position consonant with the concaves being in an open position;
[0036] FIG. 20 is an isometric view of one of the 3 concaves sieves;
[0037] FIG. 21 is an isometric view of just one of the sieve inserts;
[0038] FIG. 22 is an isometric view showing installation of one of the sieve inserts;
[0039] FIG. 23 is an isometric view of the frame assembly from underneath.
[0040] The drawings will be described in greater detail below.
DETAILED DESCRIPTION
[0041] Referring initially to FIGS. 1, 2, 3, and 4 , an articulated harvester, 10 , consists of a powered PPU, 12 , a rear grain cart, 14 , and an articulation joint, 16 , that connects PPU 12 with rear grain cart 14 . The details of articulation joint 16 are disclosed in commonly owned application Ser. No. 14/946,827 filed Nov. 20, 2015. PPU 12 carries a grainhead, 18 , operator's cab, 20 , grain cleaning and handling assembly, and engines. PPU 12 is devoid of any grain storage, such being exclusive in rear grain cart 14 . While both PPU 12 and rear grain cart 14 are shown being carried by wheel assemblies, one or both could be tracked. A screened air inlet, 15 , is located atop PPU 12 where the air likely is the cleanest around harvesting combine 10 .
[0042] An off-loading auger assembly, 22 , is in the folded home position and being carried by rear grain cart 14 . Grain cart 14 also bears a foldable roof, 24 , shown in an open position, but which can fold inwardly to cover grain stored in rear grain cart 14 . Foldable roof 24 may be made of metal, plastic, or other suitable material, but may be made of durable plastic for weight reduction and easy folding/unfolding. A grain storage bin, 28 , (see also FIG. 14 ) carried by grain cart 14 may be made of plastic also in keeping with desirable weight reduction; although, it could be made of metal also at the expense of weight. All plastic parts may be filled with particulate or fiber reinforcement in conventional fashion and could be laminate in construction. Further details on rear grain cart 14 can be found commonly owned application Ser. No. 14/946,842 filed Nov. 20, 2015.
[0043] Referring now to FIG. 4 , the operator is granted access to cab 20 by a stair assembly, 30 , that extends upwardly from just above the ground and will be more fully disclosed in commonly owned application Ser. No. ______, filed ______ (attorney docket DIL 2-035). The skin or shell has been removed in FIG. 5 to reveal the components housed within PPU 12 . A fan assembly, 32 , is located centrally for air to enter through screened air inlet 15 . This location was chosen, as it arguably will be the cleanest flow of air around PPU 12 . Radiators, as typified by a main cooling system air box, 34 , surround fan assembly 32 and are coolingly connected with a pair of engines, 36 and 38 , located on either side of main cooling fan assembly 32 . Engine 36 powers the hydraulics for articulated combine 10 , while engine 38 powers all other components of articulated combine 10 . Exhaust after treatment assembly, 40 , cleans air for emission control. When firing up the engines, which typically will be diesel engines, engine 38 is started first so that coolant flowing through engine 38 will warm up engine 36 and the hydraulic fluid for articulated combine 10 . The twin engines aspect will be described in detail in commonly owned application Ser. No. ______, filed ______ (attorney docket DIL 2-036) and the air inlet assembly will be described in detail in commonly owned application Ser. No. ______, filed ______ (attorney docket DIL 2-037). Other components visible in FIG. 5 will be described in detail below.
[0044] Looking next at FIG. 6 , grainhead 18 typically will be between about 30 and 50 feet wide and severs the crop in various fashions from its stalk or its attachment to earth. Grainhead 18 is carried by a feeder face adapter, 44 , to a feeder mechanism assembly, 50 , as described in detail in commonly-owned application Ser. No. ______, filed ______ (attorney docket DIL 2-029), which conveys the severed crop consisting of both stalk and grain. By convention in the industry, all material that is not grain is referred to as “Material Other than Grain” or, simply, “MOG”.
[0045] Progressing rearwardly, the crop material reaches the end of feeder assembly 50 at velocity and is projected rearwardly and upwardly onto the walls of a transition cone, 52 , which is a robust structure that describes shape and direction of material flow and generally funnels the flow of crop material toward both sides and the bottom of a rotor inlet cone, 52 , of a spinning rotor, 54 (see FIG. 12 ). Rotor inlet flighting, 56 , is identified as the front portion of rotor 54 that is predominately 2, 3, 4, or more large auger flights attached to the skin of rotor 54 and serve to both propel the crop material rearward into a rotor cage, 58 , and begin the rotation of the crop material (as viewed from the rear of the module) around the periphery of rotor cage 58 . The rotation of rotor 54 occurs by virtue of a pulley assembly, 42 , a gearbox, 60 , and shaft, 62 . Rotor cage 58 is the empty space located within the rotor tube and is formed by concaves, grates, and a top cover with vanes that define the rotor tube or cylinder within which the rotor rotates and provides all stationary surfaces that the grain is threshed against and separated therethrough.
[0046] The process within rotor cage 58 delivers the crop material off the end of flights 56 and onto rasp bar assemblies for grain threshing and separation (see FIG. 12 ). These rasp bar assemblies may be rough cast iron configurations that impact, move, and pinch the crop material in order to dislodge the grain from the MOG parts of the plant, such that the grain can be removed from the flow. A typical rasp bar, 64 , as are all rasp bars, is attached to rotor 54 by means of its bolting to barnacles, as typified by a barnacle, 66 , which in turn is welded to rotor 54 in carefully identified locations to form the desired spiral patterns on the rotor as a whole. The rasp bars will be located in a spiral configuration around rotor 54 such that the crop material will be rolled, twisted, and rubbed against itself, the net affect of which will be to have significantly enhanced and substantially “gentler” threshing action, thereby nearly eliminating grain damage common to units that “smack the crop with steel” to achieve threshing. Each raps bar assembly, then is composed of a rasp bar and a barnacle.
[0047] Entry into rotor cage 58 begins the threshing process, as the rasp bars rub the crop material across concaves, 70 (see also FIGS. 10 and 13 ), which are porous structures typically made of steel that surround the lower 270° of the periphery of rotor cage 58 and are divided into three sections, each of which covers 90°. Concaves 70 can have numerous actual structural constitutions, but in general provide a rough surface to cause significant rubbing and turbulence between the rasp bars and the top surface of concaves 70 . Additionally, concaves 70 also are quite porous (have holes) to allow released grain to exit through the holes to be introduced to a cleaning area, 68 . The concave inserts (often simply called “concaves”), as typified by a concave insert, 72 (see FIGS. 13 and 18 ), change from one type of surface to a different type of surface as crop type and condition dictate. Ideally and typically, this front section (˜½) of the length of rotor cage 58 can remove nearly 75% of the entrained grain from the MOG material, and coincidentally pass on perhaps more than 80% of the MOG to a separation section or cleaning section 68 that follows and is described in greater detail in commonly owned application Ser. No. ______, filed ______ (attorney docket DIL 2-032). Typical to all harvesting combines, concaves 70 are suspended from above such that they can be moved in and out relative to the rasp bars swung diameter to cause a change in the relative clearance of the rasp bars top surface to the concaves inner surface. This allows for varying aggressiveness in the threshing process contrasted to crop type and condition and will be described in detail later herein.
[0048] The separation section of rotor cage 58 is located immediately behind (upstream) the threshing section and is for most part identical to the threshing section. By tradition, the same inserts that are located in the threshing area are now called grates, 74 (see FIG. 19 ), when in this rearward portion of the process. Typically, grates 74 are fixed in place and do not adjust in and out as do concaves 70 ; however, because the mechanisms are identical to the concave supports, grates 74 could be adjusted and that capability will be disclosed herein. The intended function of grates 74 is to separate the remaining grain from the MOG; however, since the MOG to grain ratio now significantly favors the MOG, the proportion of MOG exiting grates 74 is quite a bit higher that from concaves 70 . All of this material falls downward toward cleaning system sieves 68 .
[0049] An important and new feature in rotor cage 58 is a top cover vane assembly, 76 (see FIG. 10 ), as typified by a vane, 78 , located on the underside of the flat roof section of rotor cage 58 . The vanes are basically steel angle plates that bolt thru the top cover on the one horizontal leg, and protrude downwardly into the crop flow with their 90° vertical leg. These vanes serve to regulate the speed of flow of material thru rotor cage 58 , thereby affecting the relative aggressiveness of threshing and separation. When set at an angle more perpendicular to axial flow, the vanes retard the flow rate; when set at an angel less perpendicular (“laid back” or “sped up” in the language), the vanes allow faster, less power intensive flow. All other rotary combines have a curved top cover that requires the cage vanes to be curved also. This curvature sincerely limits the range of adjustment due entirely to the fact that as (for instance) a vane that would conform to a line that is perpendicular to axial on the cage cylinder, would be curved too much to fit a position that was 30° off of perpendicular. With the flat surface disclosed herein will have on the top cover. The vanes of top cover vane assembly (see FIG. 7 ) are attached to tubular control bars, 80 and 81 , which is moved by cylinders, 82 and 83 , to control their angle. Control can be exercised remotely in cab 20 by the operator to give the operator a tool that will be effective in controlling throughput versus threshing versus separation to optimize productivity of harvester 10 . Top cover vane assembly 76 is described in great detail in commonly owned application Ser. No. _______, filed ______ (attorney docket DIL 2-30).
[0050] Finally the MOG (which by convention now changes its name to straw or residue) now located at the rear of the separation area (grates 74 ) is ready to be discharged from rotor cage 58 to be spread across the ground. In PPU 12 , this will be done quite unconventionally by discharge openings in rotor cage 58 to discharge assemblies that contain straw chopper assemblies, 90 and 92 (see FIG. 9 ), where rapidly rotating drums with numerous swinging blades will reduce the length of the residue pieces and propel them horizontally and transversely outwardly at high velocity. Assisting in the chopping process are stationary knives, (“counter knives”, “fixed knives”), not seen in the drawings, which act as shearing surfaces to hold the long residue for the swinging (sharp) knives to better cut the residue.
[0051] Shortly after chopping and propulsion, the residue pieces will encounter straw hood assemblies, 94 and 96 (see FIG. 9 ), that is used as a deflector to influence the direction of the pieces such that some continue far out away from the vehicle, while variably others fall at distances from the vehicle, causing and ideally uniform distribution of the pieces over the ground surface. PPU 12 will have two sets of these chopper assemblies and knives 90 and 92 , one on each side as seen in FIGS. 8 and 9 and described in detail in commonly assigned application Ser. No. ______, filed ______ (attorney docket DIL 2-031).
[0052] Returning to the MOG and grain that is being expelled through concaves 70 and grates 74 , these materials exit the inserts at reasonably high velocity and on a trajectory imposed by both their angular velocity from spinning in rotor cage 58 and from the centrifugal force imparted by rotation of rotor 54 , the net of which is largely an outward (if not radial) departure from rotor cage 58 down into the void below rotor cage 58 and above cleaning system assembly 68 (see FIG. 6 ) known as the “chaffer” (its purpose in the process is to help remove the bigger, lighter chaff from the grain by allowing the grain to fall through while rejecting the chaff to be blown out the rear of the machine). However, in accordance with the present disclosure, an additional cleaning component that takes advantage of that exit velocity of the material mix leaving the separation system is provided. Front Bulkhead 98 of the rotor/cage support structure has louvered slots (see FIG. 8 ) in it that will allow high velocity air being forced downwardly into a plenum to which the bulkhead is one wall, the driving force of the air being cleaning charge fan assembly (see FIG. 6 ) located above the rotor cage, in front of main cooling system air box 34 (see FIG. 6 ). The charge fan assembly will be collecting exhaust air from a cooler assembly 34 , imparting new velocity to it and sending it down through the plenum formed by front cage bulkhead 98 , rotor inlet cone 52 , a separator sidesheet, and a cover sheet to complete the plenum. The purpose being to deliver air from above PPU 12 down through the plenum and into the inlet of cleaning fan 33 , located in front of the axle, as explained in detail in U.S. Ser. No. ______ (attorney docket DIL 2-032, cited above).
[0053] As a matter of secondary assurance of high capacity, and because the disclosed PPU 12 configuration allows it, a bonus sieves assembly, as disclosed in commonly assigned application Ser. No. ______, filed ______ (attorney docket DIL 2-033), is provided. Unknown to the rest of the industry, these bonus sieves are allowed by the rear axle for harvesting combine 10 being on rear module 12 , not beside the sieves. So the frame of PPU 12 will bulge outwardly wider once past the front tires, and fill that space on each side of the main sieves with narrower, shorter sieve members, bonus sieves, that in total will add about 20% more sieve area. Moreover, remembering the condition of having a much higher MOG ratio being expelled from the rear of the separation area, this bonus sieves area will add additional cleaning area back where the cleaning is made more difficult by higher MOG concentrations, whether that be in the airstream or on the sieve surfaces.
[0054] Under the front majority of the major sieves' length, a clean grain conveyor, a belt conveyor (running rearward on the top) that catches the grain as it falls, and conveys it rear ward to a clean grain cross auger. A secondary, but equally important, function of the flat top of the conveyor is to serve as a converging plenum versus the lower sieve, such that the air being moved rearward by the cleaning fan is progressively force to be directed upward through the sieves, thus powering the pneumatic cleaning function of the cleaning system. If stray MOG were to fall through both sieves, this is yet another chance for that MOG piece to be blown rearward, and perhaps out of the system. Again, this is disclosed in detail in U.S. Ser. No. ______ (attorney docket DIL 2-032), cited above.
[0055] The fate of the separated clean grain exiting the various cleaning systems in PPU 12 and its transfer to grain cart 12 is disclosed in commonly owned application Ser. No. 14/946,827 cited above.
[0056] Finally, PPU 12 will contain a tailings return system, as disclosed in detail in commonly owned application Ser. No. ______, filed ______ (attorney docket DIL 2-034), that will be located below and aft of the aft of cleaning assembly 68 . Material that is small enough and dense enough to fall through the extreme rear section of the chaffer, referred to as a chaffer extension, and material that because of size or low density could not fall through the lower sieve will be delivered to a tailing auger trough. In the trough is a tailings cross auger, an auger with opposing flighting, that this time augers the material outward from the middle. As the material reaches the sidesheets of the major structure, it enters a tailings elevator, one on each side of the structure. Running on a sprocket on the (each) end of the cross auger will be a roller chain with rearward leaning paddles that are also canted to move the material inward against the inner wall as it is conveyed upward. The leaning and canting of the paddle reduces the conveying efficiency while also increasing the tumbling and rubbing of the unthreshed grain against the walls and outer ring of the elevator chute. This “rethreshed” material will then be introduced back into cleaning system 68 above the bonus sieves by auger flights on a tailings top drive shaft to make another attempt at proper cleaning and saving, or to be rejected again, and, in either case, it will in one way or another be ejected from the system.
[0057] At this point in the disclosure, we look at FIGS. 8 and 10 whereat the support for concaves 70 and grates 74 is shown. In particular, a front bulkhead, 98 , a middle bulkhead, 100 , and a rear bulkhead, 102 , provide support for the rotor/cage structure. Looking at FIGS. 13-22 , concaves 70 and grates 74 are disclosed in detail. A skeleton, 104 , supports and accepts concave inserts, such as concave insert 72 , and a skeleton, 105 , that supports and accepts a grate insert, 106 . There are three sieve inserts across and three sets of these inserts spanning 270°. FIG. 20 shows frame assembly 104 , concave insert 72 , a concave insert, 108 , and concave insert 110 . One end of concave insert 108 is flat plate, 109 , for permanent attachment to skeleton 104 , while the other end has a finger assembly, 112 . The finger assembly end of concave insert 108 is curved and partially goes around an upper bar, 114 , portion of skeleton 104 by virtue of its end having a U-shape to receive upper bar 114 . The insertion of concave insert 108 into skeleton 104 is seen in FIG. 22 to involve concave insert 108 being moved from the side into position with flat 109 being bolted or otherwise attached to a flat bar, 116 , of skeleton 104 and the U-shaped upper end taking in bar 114 . All of the concave inserts are attached in a same manner. In fact, the grate inserts are similarly configured and inserted into frame skeleton 105 in the same manner. The disclosed design permits easy installation and removal of any one of the concave or grate inserts. A bent finger assembly, 111 (see FIG. 19A ), is part of the skeleton assembly and is present for both the concave assembly and the grate assembly and interact with the finger ends of the concave and grate inserts to accommodate the size of the grain being handled.
[0058] Referring additionally to FIGS. 14 and 15 , the ends of skeleton 104 are configured to receive rotatable bars, 118 , 120 , and 122 , and a fixed bar, 124 . As seen more clearly in FIGS. 14 and 15 , slotted plates, 126 , 128 , and 130 , having arcuate slots are attached to rotatable bars 118 , 120 , and 122 and are rotated by a cylinder assembly, 132 , so that the finger assemblies are in a closed position. In this closed position, the sieve inserts are in a pinched configuration with respect to rotor 54 for small grain. As more clearly seen in FIGS. 16 and 17 , cylinder assembly 132 has rotated so that the finger assemblies are in an open position for large grain. Simultaneous motion is achieved by cylinder assembly being attached to link bars, 134 and 136 . A similar set of link bars are provided at the other end of the concaves assembly. The arcuate rotation results in the fingers being moved in an arcuate motion and in an up and down motion. These simultaneous motions result in the fingers, straight on one side and curved on the other side, moving closer and further apart while simultaneously moving slightly up and down. Additionally, cylinder assembly 132 can be actuated remotely by the operator. Additionally, while hydraulic cylinders are shown in the drawings, such cylinders (or actuators in general) could be pneumatic, linear actuators, electric motors, or other assemblies. Actuators are “powered” for present purposes.
[0059] While the disclosed concaves inserts surmount 270°, a lesser or greater amount of wrap could be designed into such concave inserts. Moreover, the sections of concaves can be adjusted independently to not only effect a change in clearance to the rotor, but also to achieve multiple pinch points around the periphery in the same number as the number of peripheral sections. The drawings show 3 such concave sections resulting in triple convergence of concave clearance to the rotor. The net effect of this triple convergence is to enable a single crop pass around the periphery of rotation to have threshing and separation equivalence to three separate passes from typical configurations, greatly increasing the efficiency of threshing and separation. The disclosed design, then, permits the totality of the designated “separation” area, the grates, to be reconfigurable with respect to the type of grate separation surface chosen, as opposed to being fixed sized holes. Moreover, the grates also could be designed for simple adjustment for clearance and pinch should that be desired.
[0060] The flexibility of the concave adjustment mechanism permits their synched or adjusted independently. The same goes for the grates with the proviso that the grates could be synched with the concaves. The concave inserts and grate inserts are easily and quickly inserted and withdrawn according to their disclosed design. All concave inserts and all grate inserts are the same in design, permitting any insert to be installed in any location. Finally, the concave inserts have sets of fingered panels that move closer and apart as the concave clearance is adjusted inwardly and outwardly. These fingers on the panels are offset to each other to effect great change in the open area and shape of the open area to give prescribed separation based on crop type.
[0061] Returning to FIG. 13 , it will be observed that spacers, 138 , 140 , 142 , and another not seen, provide a break between bar 118 for concaves 70 and a bar, 119 , for grates 74 . The same is true for bar 122 and a bar, 123 . Such spacers could be omitted and the respective bars be continuous for grates 74 to rotate as do concaves 70 . Alternatively, grates 74 could be constructed, as are concaves 70 for independent rotation and adjustment.
[0062] FIG. 23 shows frame assembly 143 with its various members. Of note is the bulging of the frame behind where the tires, locations 144 and 146 are located to accommodate additional treating assemblies for separation of the grain, as described above and in related patent applications. Front slotted bulkhead 98 is seen in this view also. Some of the plates will contain holes or apertures for achieving weight reduction without sacrifice of structural strength.
[0063] While the device and method have been described with reference to various embodiments, those skilled in the art will understand that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope and essence of the disclosure. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the disclosure without departing from the essential scope thereof. Therefore, it is intended that the disclosure not be limited to the particular embodiments disclosed, but that the disclosure will include all embodiments falling within the scope of the appended claims. In this application all units are in the metric system and all amounts and percentages are by weight, unless otherwise expressly indicated. Also, all citations referred herein are expressly incorporated herein by reference. | Disclosed is a rotor and cage assembly that includes a skeleton of curved spaced-apart side members affixed to laterally extending upper and lower spaced-apart members therebetween and surrounding the rotor. One of the curved spaced-apart side members is terminated with curved fingers. Three concave inserts insert laterally into the skeleton spanning 270° around the rotor. One of the concave inserts carries straight fingers that interlace between the skeleton side member curved fingers. A control assembly of plates having arcuate slots placed at 3 of the pivots of the skeleton assembly, control bars connected to the skeleton pivots, and an actuator connect to the control bars at one end effect arcuate rotation of the control bars resulting in the synchronized rotation of the arcuate slotted plates so that the interlaced straight fingers move closer together or farther apart with the fixed skeleton assembly curved fingers for different types of grain. | 0 |
[0001] The present invention is a community portal website system, composed of multilevel community portal websites, that employs a precision marketing methodology to pay resident members to look at advertisements placed by business members. Business members are able to specify a campaign period, a prepaid budget balance, and target consumer characteristics for the viewers of an advertisement. Resident members are paid by business members in two different ways. First, resident members who match the target consumer characteristics will be instantly paid a fee by a business member for accessing the business member's advertisement for a predetermined viewing time. Second, resident members are paid by business members indirectly through a lottery fund. Business members contribute to the lottery fund every time their advertisements are viewed by resident members. Lottery winners are drawn regularly, with the grand prize winners paid the largest amount.
FIELD OF THE PRESENT INVENTION
[0002] The present invention relates to a community portal website system owned and operated by a licensor, who licenses community portal websites to licensees for a fee. Fees are generated by advertisers signed up as “business members,” who pay a monetary amount every time an advertisement is viewed by a community member who lives within a specified community and demographic and is signed up as a “resident member.” A portion of the monetary amount is paid directly to the resident member, and a portion is paid to a lottery fund. The licensee regularly selects resident members as lottery fund winners and awards them cash or prizes.
[0003] Each community portal website within the community portal website system is a multilevel website tailored for a greater geographic area such as a city or county, with subsystem websites tailored for smaller geographic areas within that greater geographic area. The preferred embodiment of the present invention envisions a community portal website as comprising a third level website (city level website), with second level websites (district level websites) as subsystems of the third level website, and first level websites (community level websites) as subsystems of the second level websites.
BACKGROUND OF THE PRESENT INVENTION
[0004] In the advertising industry, consumer attraction is the most important factor. In 2010, the market size of the advertising industry in the United States was about $200 billion. Supposing there are 100 million households in the U.S., that means an average of $2,000 is spent by advertisers to get each household's attention. All of that money goes to advertising agencies and other “middlemen.” What if instead $2,000 was paid directly to consumers in the forms of cash rewards and prizes for their attention?
[0005] As an example, let's take a look at a business that prints and delivers flyers to households, paying 20 cents for each flyer (broken down into four cents for paper, seven cents for printing, and nine cents for delivery). The cost of making and distributing 10,000 flyers is 2,000 dollars. If, however, the company uploaded the flyer file on the web, it could pay as many as 10,000 consumers 20 cents to view it for the same amount of money. But it would not be worth a consumer's while to start his or her computer, browse the internet, log in to a website, and click on one ad to earn only 20 cents. However, it would be worthwhile to log into a consolidated website where hundreds of business members have uploaded their advertisements. Consumers would be willing to start up their computers, log in, and click advertisements if they could earn, say, $20 for viewing 100 ads. Moreover, a chance to win a lottery prize of $1,000,000 would gain the attention of most consumers. These are the main ideas of the present invention.
[0006] In the way of background, the website www.zip2save.com offers an online version of advertisement flyers so that people can read the flyers applicable to their city. However, because there is no consumer compensation program involved, it is unlikely that people will want to check the flyers online. Also in the way of background, in the 1990s, there were two companies, Cybergold and AllAdvantage, that paid people to view advertisements. The problem was the difficulty of getting advertisers because the process was so expensive. For example, if 30 million people viewed an advertisement, and anyone who clicked on the ad got paid fifteen cents each, with an additional ten cents charged for expenses, that amounted to $6,000,000 for one advertisement. At that time, the internet was in its start-up stage, before the advent of precision marketing database systems that enable advertisers to precisely select target consumer characteristics.
[0007] The Accurate Marketing System of the present invention means combining the concepts of “precision marketing” and “user verification.” Precision marketing simply means the system by which advertisers can precisely select target consumers by various factors. User verification means that the authenticity of the consumer is verified. This second aspect is most important because the advertiser pays for each consumer who views the advertisement, and the advertiser wants to make sure it is paying for the specifically targeted consumer.
[0008] U.S. Publication No. 2002/0095442 for “Creating Community Web Site” by Hunter et al., published on Jul. 18, 2002, shows a community website with links to information of local interest. The present invention differs from Hunter et al. in that the present invention is a “multi-level” website structure, with at least one “third-level website” representing a greater geographical area, with subsystem “second-level” and “first-level” websites representing smaller areas within that greater geographic area. In addition, Hunter et al. is primarily concerned with linking to local recreational pursuits, such as day trips, golf courses, and walking tours, whereas the present invention envisions providing a community's members the ability to earn revenue for viewing advertisements targeted to their specific community and demographic.
[0009] U.S. Pub. No. 2005/0262018 for “Business Method for Internet Advertising” by Soria, published on Nov. 24, 2005, shows a method of advertising on the internet that directs a portion of payment from the advertiser to the customer. Unlike the present invention, Soria does not utilize his method within a multi-level structure wherein persons within a specific geographic area are rewarded for viewing an advertisement.
[0010] U.S. Pub. No. 2002/1033402 for “Apparatus and Method for Recruiting, Communicating with, and Paying Participants of Interactive Advertising” by Faber et al., published on Sep. 19, 2002, shows a system by which advertisers pay participants to attend to a presentation online. Unlike the present invention, Faber et al. establishes a real-time communications link between the advertiser and the participants, whereas the present invention pays a viewer of an advertisement within a multi-level structure, based on the viewer's geographic area and demographic.
[0011] U.S. Pub. No. 2002/0147633 for “Interactive Advertisement and Reward System” by Rafizadeh, published on Oct. 10, 2002, shows a method of providing rewards to a customer who browses product-specific advertisements. Unlike the present invention, Rafizadeh does not employ a multi-level structure wherein persons within a specific geographic area and demographic are rewarded for viewing an advertisement.
SUMMARY OF THE PRESENT INVENTION
[0012] The present invention is a community portal website system owned by a licensor, consisting of one or more community portal websites that are designed as multi-level structures. Each community portal website is licensed by a licensor to a licensee. In the preferred embodiment of the present invention, the highest level of the community portal website is at the third level (a city level website), with second level websites (district level websites) as subsystems of the third level website, and first level websites (community level websites) as subsystems of the district level websites. However, different embodiments of the community portal website structure are also envisioned, as in the examples given below:
Second level website (small city level website), first level websites (community level websites) Third level website (county level website), second level websites (town level websites), first level websites (community level websites) Fourth level website (state level website), third level websites (city level websites), second level websites (district level websites), first level websites (community level websites) Fifth level website (national level website), fourth level website (state level website), third level websites (city level websites), second level websites (district level websites), first level websites (community level websites)
[0017] The community portal website structure described throughout this document, and which is the preferred embodiment of the present invention, is third level website (city level website), second level websites (district level websites), first level websites (community level websites). However, it should be understood that the structure of the present invention may embody other structures such as the examples given above, or any other structure that best meets the needs of the greater geographic area served by the present invention.
[0018] Within the community portal website structure, a first level website is provided free of charge to the community members served by that first level website. This is done by tailoring the first level website to a specific local community, whether to a local community association or the community itself. The first level website is the portal through which community members sign up free of charge to become “resident members” of the present invention, and through which they can post a limited number of announcements (i.e., free advertisements). This method of posting announcements is called the indirect posting method. Since the community portal website system utilizes a centralized database, the announcements placed by resident members through the first level website are also seen at the second level and third level websites. In addition, the first level website is the level through which resident members can view advertisements in order to receive payment. These advertisements will be targeted to specific target consumer characteristics of those within a specific community.
[0019] As an example of the precision marketing method, when a community-based nail shop advertises, its target market could be adult females within that specific community area. The present invention enables advertisers to precisely select a target consumer group by various factors, such as geographical area (i.e., specific communities), sex, age, occupation, etc. By employing the precision marketing method, the nail shop owner pays only adult females in that specific community who view that advertisement. By means of this precision marketing method, advertisers can save advertising costs while simultaneously paying consumers.
[0020] This solution is ideal for a community-based small business that can't afford to pay for expensive methods such as television, newspaper or online advertisements. Currently, the most popular advertisement method for small businesses is advertising flyers. The problem with this method is that so few people read them. Once or twice a week, a pile of flyers is delivered to a home, but they are thought of by most people as junk mail. Market research surveys show only two to three percent of people who receive ad flyers actually read them. The majority go directly into a recycling bin without being read. It is an inefficient means of advertising, but because it is relatively inexpensive, many small businesses still use it.
[0021] For example, if a small business wants to cover a local market of 10,000 households, the costs would break down as follows:
a) Paper costs: $0.04/sheet×10,000=$400 b) Printing costs (incl. material & labour): $0.07/sheet×10,000=$700 c) Delivery costs: $0.09/sheet×10,000=$900 d) Total costs: $0.20/sheet×10,000=$2,000
[0026] Since the best scenario is that only three percent of flyers will actually be read (i.e., 300 households), the actual cost for each “read flyer” is about $6.67 per flyer. This is an extremely inefficient means of advertising.
[0027] What if a business paid consumers for viewing an advertisement instead of paying middlemen like printers and delivery people? A standard TV commercial lasts 15 seconds, so if a consumer viewed an ad for a predetermined viewing time, such as 20 seconds, it would be a sufficient amount of time in which to communicate the business's message. Assuming a business pays $0.20 for each paper flyer, paying a consumer $0.10 for viewing an ad is a better bargain for the advertiser, and for the consumer too, since if a consumer views 30 ads a day, it will take only 10 minutes each day and he or she will make $3.00 extra income a day and $90 a month. In such a situation, consumers are naturally going to appreciate the advertisers. The advertisers are happy too, because at no extra cost consumers are being reached at a rate of effectiveness 3,233% greater than the conventional method. Finally, the website operating company (franchisee) is happy too, because when the advertiser pays $0.15 for a viewed ad, $0.05 goes to the franchisee.
[0028] But what if only a small number of consumers view the ad? If, for example, only 300 consumers view an ad, the advertiser will pay only $45. Compared to the conventional method, the advertiser saves $1,955 (97.75% of cost) because there is no printed paper going directly to recycling bins.
[0029] When a business places an advertisement on Google, MSN, Yahoo, or Youtube, anybody in the world can view it. But a local business based in Denver, Colo. doesn't want to pay a viewer who lives in New York, LA or somewhere in Asia. The solution is existing web technology that can tell a consumer's location by IP Address. For example, if a user accesses www.google.com from his or her home computer with an IP address of 67.169.132.112, Google's server recognizes that IP network address of 67.169.0.0 is allocated to an ‘class B’ ISP providing service in the Greater Chicago area. The Google server then pulls out the Chicago area advertisement pool from its database and shows them randomly to the user. If the three million users in the Greater Chicago area accessed Google.com, and were paid to view an ad placed there, the advertiser would pay $450,000 for a one-time advertisement. Therefore if a neighborhood bar advertised a grand opening on the web, even though the market segment to be targeted is probably 10,000 people that live in that neighborhood area, the ad would be viewed all over the Greater Chicago area, and at a cost of $450,000.
[0030] The solution is a method or system by which a local business can advertise precisely to target geographical communities and consumers only, thus attracting more customers while saving on advertising costs, and compensating viewers for their advertisement viewing labors. With the present invention, an advertiser can select certain community level websites (each servicing, say, 10,000 users) out of the numerous community level websites in the city level website.
[0031] The present invention enables local businesses to precisely target their consumer audience, and also to attract consumers by paying them to view advertisements. A chief difference between the present invention and previous community website concepts is that previous inventions have been “uni-level,” but the present invention is “multi-level.” For example, the website Kijiji (accessible at www.kijiji.com) is uni-level in structure, as is the network of Patch sites (accessible at www.patch.com). A visitor to either site is required to click a specific U.S. state, then a specific city or town within that state in order to access information. There is no information listed for the state, county, etc.; only the city or town has its own website. Many of these uni-level websites have failed or been unsuccessful, because in terms of classified advertisements the widest possible exposure is the key to success.
[0032] As an example, Bob is living in the town of Albany, Calif. The population of his town is only 18,500. He wants to sell his house and thinks that $250,000 is a fair price, so he posts an ad on the Patch site for Albany. Because Albany is a small town, only a hundred people click on the ad and he doesn't get an offer at that price. However, there are numerous neighbor cities and towns within 30 miles diameter of Albany. If Bob advertises in those cities and towns as well, he might attract more buyers and more offers. Advertisers want more exposure, which a uni-level community website cannot provide. For this reason, advertisers prefer higher level media to cover a wide area, not only a town. Now Bob has to advertise in 12 other cities individually, or pay a much higher advertisement fee to a major media outlet for county-wide coverage. Uni-level websites such as Patch.com may be a good source of information for local news and announcements, but are far less effective for advertisements.
[0033] A multi-level website such as the present invention is far different, and far more effective. An advertisement posted on the first level website is at the same time visible on the higher-level websites. When an advertiser places an advertisement for view at a community level website, it is simultaneously exposed at higher level websites, such as the district level and city level or county level. Advertisers are still visible in their community, but are also seen in wider geographical areas without any extra cost. This is possible because of the multi-level community website structure with a centralized database, which is one of the main concepts of the present invention.
[0034] Bob, the Albany resident, is simultaneously a resident of Alameda County in the state of California. With the present invention, when Bob places an advertisement at the Albany city level website, it will also be visible at the Alameda county level website, and the California state level website. Modern web technology makes it possible with a central database system.
[0035] The present patent is to cover not only the website of the present invention, but its ability to be used on mobile applications such as smart phones, etc. People can easily view ads on mobile devices on buses, subway trains or during coffee breaks.
[0036] The present invention could also be utilized as a market research or online survey tool. Researchers could access the database of resident members and pay those who respond to a survey.
[0000] In summary, the key aspects of the present invention are:
1. A multi-level community website structure with a centralized database
2. Consumer signs up as a resident member with his or her profile
3. Advertisers sign up as business members, and can precisely specify resident members' target consumer characteristics
4. A business member selects a campaign period and monetary amount to be paid when the advertisement is viewed
5. Resident members who match the target consumer characteristics and view the advertisement can submit an online ticket for entry into a lottery
6. Upon submitting the online ticket, the resident member is instantly paid a first portion amount of the monetary amount, with a second portion amount forwarded to a lottery fund, and a third portion amount paid to the licensee of the community portal website
7. The licensee (or licensor) regularly (e.g., weekly) draws grand prize winners using a prescribed method (explained below in the detailed description).
[0037] The licensor of the present invention is the owner and operator of the prototype community portal website system accessible via the internet at www.communityboard.ca. This community portal website system is in continuous development, and is owned and operated by Community Board Inc., an Alberta corporation in the City of Calgary, Alberta, Canada. The community portal websites within this community portal website system serve as the model for the community portal websites established in the present invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0038] FIG. 1 is a diagram of a community portal website ( 20 ), with a third level website ( 70 ) and subordinate second level websites ( 60 ) and first level websites ( 30 ).
[0039] FIG. 2 illustrates the process of a resident member ( 50 ) viewing an advertisement and the apportioning of a monetary amount ( 155 ), with a first portion amount ( 160 ) apportioned to a resident member's personal account ( 55 ), a second portion amount ( 165 ) apportioned to a lottery fund ( 175 ), and a third portion amount ( 168 ) apportioned to the licensee ( 80 ).
[0040] FIG. 3 shows an example of an adview and lottery playing screen ( 190 ) with an advertisement ( 125 ), lottery numbers ( 195 ) chosen by the user, and “Submit” button ( 220 ).
[0041] FIG. 4 shows a sample table of the lottery number database ( 230 ) in which all possible two-digit lottery numbers are accounted for.
DETAILED DESCRIPTION OF THE INVENTION
[0042] The present invention is a method of providing websites for use by community members, while simultaneously allowing them to get paid for viewing advertisements ( 125 ). In this method, the licensor ( 75 ) owns and operates a community portal website system ( 10 ) that consists of numerous community portal websites ( 20 ) operated by licensees ( 80 ). Each community portal website ( 20 ) is targeted to a geographic area, with multiple “subsystem” websites tailored to smaller areas within that geographic area. These subsystem websites, explained in further detail below, are adapted to the local communities they serve. The licensor ( 75 ) hosts these websites on a centralized database ( 25 ) which is a computer. A community portal website ( 20 ) can be structured in different ways, but the preferred embodiment of the present invention is envisioned as a community portal website ( 20 ) with a third level website ( 70 ), and subordinate second level websites ( 60 ) and first level websites ( 30 ).
[0043] FIG. 1 is a diagram of a community portal website ( 20 ) in the preferred embodiment of the present invention, with a third level website ( 70 ) and its subordinate second level websites ( 60 ) and first level websites ( 30 ) placed on a centralized database ( 25 ). A community portal website ( 20 ) is shown with a number of first level websites ( 30 ) at the community level that are subsystems of second level websites ( 60 ) at the district level, which are in turn subsystems of a third level website ( 70 ) at the city level. It should be understood that other embodiments of the community portal website ( 20 ) may use additional levels or other structures (such as a third level website ( 70 ) at the county level, with subsystem second level websites ( 60 ) at the town level, etc.) without departing from the core concepts of the present invention. However, within the detailed description that follows, the preferred embodiment as shown in FIG. 1 is used as the model.
[0044] The present invention is envisioned as a for-profit corporation, with a licensor ( 75 ), licensees ( 80 ), business members ( 90 ) and resident members ( 50 ). In the preferred embodiment, the licensor ( 75 ) will operate the community portal website system ( 10 ), and licensees ( 80 ) will operate the community portal websites ( 20 ), although other management structures are possible. First level websites ( 30 ) are distributed free of charge to either community associations ( 40 ) or specific local communities ( 45 ) for use by community residents. The first level websites ( 30 ) are the portals through which community residents can become resident members ( 50 ) free of charge, and post a limited number of announcements ( 115 ) for free as well. These first level websites ( 30 ) are designed so that information entered in any first level website ( 30 ) is stored in the centralized database ( 25 ) and is thus accessible simultaneously at “all levels” of the community portal website ( 20 ), i.e., at the relevant first level websites ( 30 ), second level websites ( 60 ), and third level website ( 70 ).
[0045] When establishing a personal account ( 55 ) at a first level website ( 30 ), a resident member ( 50 ) will be required to complete a detailed consumer profile ( 130 ) that will reveal the target consumer characteristics ( 145 ) of the resident member ( 50 ). These target consumer characteristics ( 145 ) could include gender, age, income, occupation, education, household size, and other factors. The local community ( 45 ) of the resident member ( 50 ) is also important, since business members ( 90 ) will target resident members ( 50 ) who reside in particular target communities ( 185 ).
[0046] The second level websites ( 60 ) are the portals through which advertisers will routinely sign up as business members ( 90 ) of the community portal website ( 20 ) and place advertisements ( 125 ). However, business members ( 90 ) may also be permitted to sign up on higher level websites depending on the size of the business and its locations. (For example, a chain store with a national reach would be permitted to sign up as a business member ( 90 ) at a national level website.) Due to the centralized database ( 25 ), every advertisement ( 125 ) posted at a second level website ( 60 ) is posted simultaneously at the relevant first level websites ( 30 ) and third level website ( 70 ).
[0047] When placing an advertisement ( 125 ), business members ( 90 ) select information such as target communities ( 185 ) and target consumer characteristics ( 145 ) of the resident members ( 50 ) who will be paid to view the advertisement ( 125 ). A business member ( 90 ) will be asked to:
1) Select the targeted first level websites ( 30 ) assigned to one or more target communities ( 185 ). Some or all of the communities in the city can be selected 2) Select a campaign period ( 135 ) (i.e., date range) of the advertisement ( 125 ) 3) Deposit a prepaid budget balance ( 140 ) 4) Specify target consumer characteristics ( 145 ), such as, age, sex, occupation, interest, etc.
[0052] For example, the business member ( 90 ) selects:
1) First level websites ( 30 ) serving target communities ( 185 ) A, B, and C 2) Campaign period ( 135 ) of Oct. 10, 2011 until Oct. 24, 2011 3) Prepaid budget balance ( 140 ) of $2,000 for advertisement ( 125 ) 4) Target consumer characteristics ( 145 ): age: 15 or older; sex: male; occupation: any
[0057] During the campaign period ( 135 ), when a resident member ( 50 ) of target communities ( 185 ) A, B, or C who falls within the target consumer characteristics ( 145 ) (in this example, age: 15 or older; sex: male; occupation: any) clicks on and views the specific advertisement ( 125 ) for a predetermined viewing time ( 150 ) (e.g., 20 seconds), then he will be directed to enter five two-digit lottery numbers ( 195 ) within an adview and lottery playing screen ( 190 ) (shown in FIG. 3 and described in detail further below). When he clicks the “Submit” button ( 220 ), a monetary amount ( 155 ) (e.g., 15 cents) is debited from the prepaid budget balance ( 140 ), and a first portion amount ( 160 ) (e.g., 5 cents) is instantly credited to the personal account ( 55 ) of the resident member ( 50 ). (However, if the resident member ( 50 ) views the same advertisement ( 125 ) in the second level website ( 60 ) or third level website ( 70 ), he does not receive payment.) A second portion amount ( 165 ) (e.g., 5 cents) is transferred to a lottery fund ( 175 ). A third portion amount ( 168 ) (e.g., 5 cents) is sales revenue ( 120 ) for the licensee ( 80 ) of the present invention. The lottery numbers ( 195 ) submitted by the resident member ( 50 ) are entered into a lottery number database ( 230 ). The licensee ( 80 ) or licensor ( 75 ) regularly draws winning numbers ( 225 ) from the lottery database ( 230 ) (shown in FIG. 4 and described in detail further below), selecting the least frequently entered lottery numbers ( 195 ) as the winning numbers ( 225 ), and paying the winners money or prizes out of the lottery fund ( 175 ).
[0058] FIG. 2 illustrates the process of a resident member ( 50 ) viewing an advertisement and the apportioning of a monetary amount ( 155 ), with a first portion amount ( 160 ) apportioned to a resident member's personal account ( 55 ), a second portion amount ( 165 ) apportioned to a lottery fund ( 175 ), and a third portion amount ( 168 ) apportioned to the licensee ( 80 ). A resident member ( 50 ) of one of the target communities ( 185 ) who meets the target consumer characteristics ( 145 ) views a specific advertisement ( 125 ) for a predetermined viewing time ( 150 ). From the prepaid budget balance ( 140 ) the monetary amount ( 155 ) is then deducted, and the first portion amount ( 160 ) is credited to the resident member's personal account ( 55 ), the second portion amount ( 165 ) is credited to the lottery fund ( 175 ), and the third portion amount ( 168 ) is credited to the licensee ( 80 ).
[0059] FIG. 3 shows an example of an adview and lottery playing screen ( 190 ) in the preferred embodiment of the present invention. The adview and lottery playing screen ( 190 ) contains an advertisement ( 125 ), a section where five two-digit lottery numbers ( 195 ) are entered by the user, and a “Submit” button ( 220 ) by which the user submits the lottery numbers ( 195 ).
[0060] FIG. 4 shows a sample table of the lottery number database ( 230 ) in which all possible two-digit lottery numbers are accounted for. On the top of the lottery number database ( 230 ) are shown example winning numbers ( 225 ) (the numbers being 06, 97, 55, 15 and 60). The winning numbers ( 225 ) that are selected are the least frequently selected lottery numbers submitted by resident members. Every time a resident member submits five two-digit lottery numbers from an adview and lottery playing screen, the lottery numbers are counted and saved into the lottery number database ( 230 ) placed within the centralized database. The least frequently entered lottery numbers are chosen as the winning numbers ( 225 ).
[0061] Continuing with the detailed description of the preferred embodiment of the present invention, an advertisement ( 125 ) is automatically taken down when the prepaid budget balance ( 140 ) is depleted. In order to extend the advertisement ( 125 ) for a longer campaign period ( 135 ), the business member ( 90 ) must add more funds to the prepaid budget balance ( 140 ). On the other hand, if there are still funds remaining in the prepaid budget balance ( 140 ) at the end of the campaign period ( 135 ), the funds remaining are refunded to the business member ( 90 ). This aspect of the present invention guarantees a business member ( 90 ) pays only when his or her advertisement ( 125 ) is viewed by a resident member ( 50 ) who matches the specified target consumer characteristics ( 145 ). Business members ( 90 ) can thus increase their consumer reach ratio since resident members ( 50 ) are paid only when they view advertisements ( 125 ) aimed at their target demographic. Business members ( 90 ) and resident members ( 50 ) meet directly on the present invention, and they split the advertisement costs that the business members ( 90 ) saved by not paying middlemen.
[0062] As another example, a neighborhood bar owner is a business member ( 90 ) advertising only to a target community ( 185 ) with 10,000 residents that is served by a first level website ( 30 ). The business member ( 90 ) specifies the target consumer characteristics ( 145 ) as males over 18 years of age within the target community ( 185 ), so the estimated number of his target consumers is 4,000. The owner deposits a prepaid budget balance ( 140 ) of $600 ($0.15×4,000) for a campaign period ( 135 ) of two weeks. During the campaign period ( 135 ), 2,000 resident members ( 50 ) of the target community ( 185 ) who meet the target consumer characteristics ( 145 ) view the advertisement ( 125 ) for the predetermined viewing time ( 150 ). For each view, $0.15 is debited from the prepaid budget balance ( 140 ), with a first portion amount ( 160 ) of $0.05 deposited into the personal account ( 55 ) of each viewing resident member ( 50 ), a second portion amount ( 165 ) of $0.05 deposited into the lottery fund ( 175 ), and a third portion amount ( 168 ) of $0.05 paid to the licensee ( 80 ). With payment of $0.15 per view, a total of $300 is debited from the prepaid budget balance ( 140 ). The remaining prepaid budget balance ( 140 ) of $300 is refunded to the business member ( 90 ) upon the expiration of the campaign period ( 135 ).
[0063] In summary, each community portal website ( 20 ) has been intentionally designed with a unique membership system that breaks down to resident members ( 50 ) and business members ( 90 ). In order to place an announcement ( 115 ) on the community portal website ( 20 ), the resident member ( 50 ) must sign up for a free personal account ( 55 ) and log into the community portal website ( 20 ). Resident members ( 50 ) are those who live in one of the communities served by the community portal website ( 20 ). The resident members ( 50 ) are allowed to post a limited number of announcements ( 115 ) without charge via a computer. Resident members ( 50 ) are only allowed to post an announcement ( 115 ) through the first level website ( 30 ) of the specific community in which they reside. For business members ( 90 ), in order to place an advertisement ( 125 ) on the community portal website ( 20 ), the business member ( 90 ) must sign up for a business account ( 170 ). Each first level website ( 30 ) is provided free of charge by the licensee ( 80 ) for use by a specific community association ( 40 ) or local community ( 45 ). This is done by tailoring the first level website ( 30 ) to a community association ( 40 ) for use by the community association ( 40 ) and its community residents, or by tailoring the first level website ( 30 ) to a particular local community ( 45 ) (i.e., neighborhood, political district, etc.). Each first level website ( 30 ) is a subsystem of a second level website ( 60 ), and each second level website ( 60 ) is a subsystem of a third level website ( 70 ), just as each community is a subsystem of the district and city where it is geographically located. At the third level website ( 70 ) are displayed all announcements ( 115 ) and advertisements ( 125 ) placed at the subsystem first level websites ( 30 ) and second level websites ( 60 ), since the community portal website system ( 10 ) utilizes a centralized database ( 25 ).
[0064] In an additional embodiment of the present invention, resident members ( 50 ) are not required to be verified when they sign up as resident members ( 50 ), but without verification they may not be paid or may be paid a lower amount (e.g., 1 cent) for each advertisement ( 125 ) viewed. However, if the resident member ( 50 ) provides a government-issued identification number, such as one found on a driver's license or passport, the status of the resident member ( 50 ) is changed to verified, and the resident member ( 50 ) can then be paid in full (i.e., 5 cents) for viewing an advertisement ( 125 ). In addition, only verified members are eligible to win additional prizes.
[0065] The business model of the present invention is also suitable as a smart phone mobile application. Resident members ( 50 ) can easily access their first level website ( 30 ) with smart phones, and earn extra income while commuting on a bus or train, or during a coffee break. Therefore it is desired that the present invention be protected under patent in the mobile application area as well.
[0066] The present invention can also be applied as a market research or online survey tool as well. Researchers or institutes can gain precise access to consumers or a respondent database for a fee, and pay respondents for their time and labor.
[0067] In conclusion, the present invention is a method for creating a community portal website system ( 10 ), the method comprising creating at least one community portal website ( 20 ) within the community portal website system ( 10 ) on a computer; creating a third level website ( 70 ), the third level website ( 70 ) being a subsystem of the community portal website ( 20 ) on the computer; creating a second level website ( 60 ), the second level website ( 60 ) being a subsystem of the third level website ( 70 ) on the computer; creating a first level website ( 30 ), the first level website ( 30 ) being a subsystem of the second level website ( 60 ) on the computer; the computer providing use of the community portal website ( 20 ) free of charge to a resident member ( 50 ) of a local community ( 45 ); the resident member ( 50 ) establishing a personal account ( 55 ) containing a detailed consumer profile ( 130 ) having target consumer characteristics ( 145 ); the computer receiving an announcement ( 115 ) placed by the resident member ( 50 ) on the community portal website ( 20 ); the computer providing use of the community portal website ( 20 ) to a business member ( 90 ); the business member ( 90 ) establishing a business account ( 170 ); the computer receiving an advertisement ( 125 ) placed by a business member ( 90 ) on the community portal website ( 20 ); and the computer charging the business member ( 90 ) a monetary amount ( 155 ) when an advertisement ( 125 ) placed by the business member ( 90 ) on the community portal website ( 20 ), is viewed by a resident member ( 50 ) according to target consumer characteristics ( 145 ) set by the business member ( 90 );
[0068] In addition, the present invention further comprises transferring a prepaid budget balance ( 140 ) from the business member ( 90 ) for the advertisement ( 125 ) to a licensee ( 80 ) of the community portal website ( 20 ); the resident member ( 50 ) viewing the advertisement ( 125 ) on an adview and lottery playing screen ( 190 ) for a predetermined viewing time ( 150 ); the resident member ( 50 ) selecting and submitting lottery numbers ( 195 ) after viewing the advertisement ( 125 ) for a predetermined viewing time ( 150 ); transferring the monetary amount ( 155 ) from the prepaid budget balance ( 140 ) upon said viewing the advertisement ( 125 ) for a predetermined viewing time ( 150 ); giving a first portion amount ( 160 ) of the monetary amount ( 155 ) to the resident member ( 50 ) for said viewing the advertisement ( 125 ) for a predetermined viewing time ( 150 ); giving a second portion amount ( 165 ) of the monetary amount ( 155 ) to a lottery fund ( 175 ) for said viewing the advertisement ( 125 ) for a predetermined viewing time ( 150 ); giving a third portion amount ( 168 ) of the monetary amount ( 155 ) to the licensee ( 80 ) for said viewing the advertisement ( 125 ) for a predetermined viewing time ( 150 ), the third portion amount ( 168 ) being sales revenue ( 120 ).
[0069] Finally, the present invention further comprises selecting winning lottery numbers ( 195 ), choosing a winning resident member ( 50 ) that has chosen the winning lottery numbers, and paying the winning resident member from the lottery fund ( 175 ); wherein said selecting winning lottery numbers ( 195 ) is by frequency, with the least frequently selected lottery numbers ( 195 ) picked as winning numbers; and further comprising hosting and maintaining the at least one community portal website ( 20 ) on a centralized database ( 25 ) so that the third level website ( 70 ), the second level website ( 60 ), and the first level website ( 30 ) are connected and networked together.
[0070] Having illustrated the present invention, it should be understood that various adjustments and versions might be implemented without venturing away from the essence of the present invention. The present invention is not limited to the embodiments described above, and should be interpreted as any and all embodiments within the scope of the following claims. | A community portal website system composed of multilevel community portal websites, employing a precision marketing method to pay resident members to look at advertisements placed by business members. Business members are able to specify a campaign period, a prepaid budget balance, and target consumer characteristics for the viewers of an advertisement. Resident members are paid by business members both directly and indirectly. Resident members who match the target consumer characteristics will be directly paid a fee for accessing an advertisement for a predetermined viewing time. Resident members are also paid indirectly by business members by means of a lottery fund. Business members contribute to the lottery fund every time their advertisements are viewed by resident members. A winner of the lottery fund is drawn regularly by the licensor or licensee, and the grand prize winner is paid a substantial amount. | 6 |
This application is a continuation of U.S. application Ser. No. 08/539,051, filed on Oct. 4, 1995 now U.S. Pat. No. 6,798,394.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an active matrix panel using thin film transistors (TFTs).
2. Description of the Related Art
FIG. 12 shows a conventional active matrix panel. In an active matrix panel 12001 , as disclosed in Japanese Patent unexamined published No. 1-289917, a source line driver circuit 12002 , a gate line driver circuit 12003 , and a pixel matrix 12004 are formed on the same (single) substrate.
The source line driver circuit 12002 has a shift register 12005 and a sample holding circuit 12006 formed by TFTs and is connected to the pixel matrix 12004 through a source line 12007 .
The gate line driver circuit 12003 has a shift register 12008 and a buffer circuit 12009 and is connected with the pixel matrix 12004 through a gate line 12010 .
In the pixel matrix 12004 , a pixel 12012 is formed at a intersection of the source line 12007 and the gate line 12010 and has a TFT 12013 and a liquid crystal cell 12014 .
FIG. 13 shows a system for processing image data stored in a memory device such as a random access memory (RAM) using a software by a microcomputer. This system has a liquid crystal display device 13001 , a digital signal/analog signal converting circuit (D/A converting circuit) 13002 , an image data memory device 13003 , an image processing system 13004 including a microcomputer (not shown), a data bus 13005 , and an address bus 13006 . Numeral 13007 represents a memory device control signal, numeral 13008 represents a control signal for the liquid crystal display device 13001 and the D/A converting circuit 13002 .
The operation is described below. The contents of image processing are programmed by C language or the like and then compiled in the system 13004 . In accordance with the contents of the image processing, the image data stored in the memory device 13003 is read out on the data bus 13005 , and then data processing is performed by the system 13004 . The processed image data is stored in the memory device 13003 or displayed on the liquid crystal display device 13001 through the DA converting circuit 13002 . Thus, the liquid crystal display device 13001 has only function for displaying the image data.
In a conventional active matrix panel, there are the following problems.
(1) Miniaturization of a display device and a system is hindered.
Conventionally, as shown in FIG. 12 , since an active matrix panel has only a circuit for driving each pixel in a pixel matrix, access to a circuit for displaying the pixel circuit, in particular, an image processing system, is performed from an external of the active matrix panel. Recently, because of increase of image data and complication of data processing, processing in an external is increased, so that the amount of the data processing exceeds processing capacity of a microprocessing unit (MPU). Accordingly, in order to decrease the amount of data processing of the MPU, an exclusive external processing unit is incorporated in a semiconductor integrated circuit. However, this increases the number of parts for an image display apparatus having image processing operation and hinders miniaturization of a system.
(2) A region which is not used is present in a panel.
Since a conventional active matrix panel includes driver circuits for pixels, gate lines and source lines, a region which is not used is present in a panel. If an external part can be arranged in the region, further miniaturization of a display system can be performed by effectively using a physical space.
(3) A high speed operation of a system for performing image processing is prevented.
In order to control pixels, it is necessary to operate an MPU in a system other than a panel. However, since an image processing technique is complexed year by year and therefore a software is complexed and increased, a data processing time of an MPU is increased and an access time to a memory device is also increased. This is because an MPU ensures a data bus to access the memory device. To solve this, it is effective to perform parallel processing by using a special purpose hardware. However, the number of parts increases. Therefore, the number of parts is decreased. By this, a system cannot be operated at a high speed, so that a process time of a MPU is further increased.
SUMMARY OF THE INVENTION
An object of the present invention is to solve the above problems and to provide an active matrix panel having a high speed with miniaturization.
According to the present invention, there is provided an active matrix panel including: a first transparent substrate; a second transparent substrate arranged opposite to the first transparent substrate; a liquid crystal material arranged between the first and second transparent substrate, wherein the first transparent substrate includes, a plurality of gate lines, a plurality of source lines, a plurality of pixel thin film transistors formed in intersections of the gate lines and the source lines, a gate line driver circuit which is formed by first thin film transistors and connected to the gate lines, a source line driver circuit which is formed by second thin film transistors and connected to the source line, and
a processing circuit, formed by the third thin film transistors, for processing signals supplied to the source lines.
The processing circuit has at least one of the following elements:
(1) a standard clock generator circuit constructed by a P-type, an N-type or a complementary type MOS transistor formed using a silicon film, or a thin film diode of MIM (metal-insulator metal), NIN, PIP, PIN, NIP or the like;
(2) a counter circuit constructed by a P-type, an N-type or a complementary type MOS transistor formed using a silicon film, or a thin film diode of MIM (metal-insulator metal), NIN, PIP, PIN, NIP or the like;
(3) a divider circuit constructed by a P-type, an N-type or a complementary type MOS transistor formed using a silicon film, or a thin film diode of MIM (metal-insulator metal), NIN, PIP, PIN, NIP or the like;
(4) a transferring element circuit for transferring a signal from external to the active matrix panel, constructed by a P-type, an N-type or a complementary type MOS transistor formed using a silicon film, or a thin film diode of MIM (metal-insulator metal), NIN, PIP, PIN, NIP or the like;
(5) a transferring element circuit for transferring a signal from the active matrix panel to the external, constructed by a P-type, an N-type or a complementary type MOS transistor formed using a silicon film, or a thin film diode of MIM (metal-insulator metal), NIN, PIP, PIN, NIP or the like; and
(6) a transferring element circuit for transferring a signal from the active matrix panel to external and transferring a signal from the external to the active matrix panel, constructed by a P-type, an N-type or a complementary type MOS transistor formed using a silicon film, or a thin film diode of MIM (metal-insulator metal), NIN, PIP, PIN, NIP or the like.
In the above structure of the present invention, the image data is read out from a plurality of memory devices for storing image data under readout control and then processed, so that the processed image data is transferred to pixels to display the image data on the pixels. That is, in the active matrix panel, a pixel matrix is driven, and further, processing, signal transfer from the active matrix panel to the external, and control of memory devices can be performed.
Therefore, without operation of an MPU, image data is processed and displayed on the pixel matrix by direct accesses to the plurality of memory devices, and the number of parts for data processing can be small.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows an active matrix panel of an embodiment of the present invention;
FIG. 2 shows a display system of the embodiment;
FIG. 3 shows steps of an algorithm for mask processing;
FIGS. 4A and 4B show examples of image data;
FIG. 5 shows steps of an algorithm which data is weighted for mask processing;
FIG. 6 shows a pixel range in which mask processing is performed;
FIG. 7 shows a display system of another embodiment;
FIGS. 8 and 9 show a bidirectional buffer;
FIG. 10 shows an example of mask processing to a portion of display area;
FIG. 11 shows an active matrix panel of another embodiment;
FIG. 12 shows a conventional active matrix panel; and
FIG. 13 shows a conventional data processing system.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Embodiment 1
In the embodiment, a method for mask processing (decrease of noise of an image) is described as concrete image processing. The mask processing is necessary to correct an image, in particular, to remove isolated point noise in a case wherein image data is produced from image reading apparatus such as a handy scanner.
FIG. 1 shows an active matrix panel of Embodiment 1, and the following circuits are formed on the same transparent substrate.
In an active matrix panel 1001 , a source line 1002 having N-lines and a gate line 1003 having M-lines are provided at a matrix form, and pixels 1004 are connected to intersections of the source line 1002 and the gate line 1003 , respectively. Accordingly, since the pixels 1004 are provided at N×M matrices by arranging N-pixels in a horizontal direction (X-direction) and M-pixels in a vertical direction (Y-direction), a desired one of the pixels 1004 can be determined by designating an address A(x,y).
The source line 1002 is connected to a source driver circuit 1024 through sample hold circuits 1005 . The gate line 1003 is connected to the outputs of a gate driver circuit 1023 . A clock line 1006 and a start line 1007 are connected to the inputs of the gate driver circuit 1023 . A video line 1008 is connected to the input of the sample hold circuit 1005 . A clock line 1009 and a start line 1010 are connected to the source driver circuit 1024 . The gate driver circuit 1023 and the source driver circuit 1024 are formed by using a P-type, an N-type, or a complementary type MOS thin film transistor (TFT), or a thin film diode of MIM (metal-insulator metal), NIN, PIP, PIN, NIP or the like.
Also, in the active matrix panel 1001 , a circuit for designating an address of the pixels 1004 to be mask-processed is provided. Through a standard clock line 1026 , the output of a standard clock generating circuit 1025 is connected to an X-coordinate counter circuit 1011 for counting an X-coordinate value, a Y-coordinate counter circuit 1012 for counting a Y-coordinate value, and a memory device control circuit 1013 for generating a clock signal to control read and write to external memory devices (not shown). The outputs of the counter circuits 1011 and 1012 are sequentially connected to a coordinate converting circuit 1015 which is connected to an address holding circuit 1016 , address buffers 1018 , and address buses 1019 , and output to an external control portion (not shown). The output of the memory device control circuit 1013 is connected to the external control portion outside the active matrix panel 1001 through a clock buffer 1027 by a signal on an averaging start signal line 1028 . The counter circuits 1011 and 1012 , the memory device control circuit 1013 , the coordinate converting circuit 1015 , and the address holding circuit 1016 are formed by using a P-type, an N-type, or a complementary type MOS TFT, or a thin film diode of MIM (metal-insulator metal), NIN, PIP, PIN, NIP or the like.
Further, in the active matrix panel 1001 , a data processing circuit 1014 for performing image processing is provided. An input and output control circuit 1017 which can read and write data, an input and output select signal line 1020 , bidirectional buffers 1021 , and data buses 1022 are sequentially connected to the data processing circuit 1014 , and each element can input and output a signal (data). The data buses 1022 are connected to the external control portion outside the active matrix panel 1001 . The data processing circuit 1014 and the input and output control circuit 1017 are formed by using a P-type, an N-type, or a complementary type MOS TFT, or a thin film diode of MIM (metal-insulator metal), NIN, PIP, PIN, NIP or the like.
FIG. 2 shows a display system. A memory device 2001 for storing image data and a microprocessing unit (MPU) 2002 for controlling the entire system are provided outside the active matrix panel 1001 . By the address buses 1019 , the outputs of the active matrix panel 1001 and the MPU 2002 are connected to the memory device 2001 . Also, by the data buses 1022 , the bidirectional buffer 1021 of the active matrix panel 1001 , the memory device 2001 , and the MPU 2002 can input and output a signal (data). The data buses 1022 are connected to a D/A converter 2003 . The D/A converter 2003 is connected to the active matrix panel 1001 through the video signal line 1008 . By a memory device control line 2004 , the active matrix panel 1001 is connected to the memory device 2001 and the MPU 2002 . Also, by a control signal line 2005 , the active matrix panel 1001 is connected to the MPU 2002 .
FIGS. 8 and 9 show examples of a bidirectional buffer. In FIG. 8 , an output pin 8001 is connected to a connection terminal connecting a drain electrode of a P-type transistor 8002 with a source electrode of an N-type transistor 8003 . A gate electrode of the P-type transistor 8002 is connected to the output of an NAND circuit 8004 , and a gate electrode of the N-type transistor 8003 is connected to the output of an NOR circuit 8005 . One of input terminals of the NAND circuit 8004 is connected to an input pin 8009 , and the other input terminal of the NAND circuit 8004 is connected to an inverter circuit 8006 . Also, one of input terminals of the NOR circuit 8005 is connected to the input pin 8009 , and the other input terminal of the NOR circuit 8005 is connected to an inverter circuit 8007 . The output of the inverter circuit 8007 is connected to the inverter circuit 8006 . An output state control pin 8008 is connected to the inverter circuit 8007 .
In FIG. 9 , a bidirectional pin 9001 is connected to an output terminal of a tristate buffer 9002 and an input terminal of an input buffer 9003 . The tristate buffer 9002 is connected to an input pin 9004 and an input and output select pin 9005 . The input buffer 9003 is connected to an input pin 9006 .
In mask processing, when a signal on the averaging start signal line 1028 is a H (high) level, in synchronous with a clock signal generated by the standard clock generating circuit 1025 , the X- and Y-coordinate counter circuits 1011 and 1012 count up a coordinate (x,y), from the coordinate ( 2 , 2 ), sequentially.
When the signal on the averaging start signal line 1028 is a L (low) level, the X- and Y-coordinate counter circuits 1011 and 1012 stop count of the coordinate, so that the coordinate (x,y) is determined. In the coordinate converting circuit 1015 , an address A(x,y) of the pixels 1004 is determined in accordance with the coordinate (x,y). Therefore, image data D(x,y) of the address A(x,y) in the pixels 1004 is mask-processed.
FIG. 3 shows steps of algorithm for mask processing. The address A(x,y) determined by the coordinate converting circuit 1015 is stored in the address holding circuit 1016 and output to the memory device 2001 through the address buffers 1018 and the address buses 1019 at the same time. The image data D(x,y) is read out from the memory device 2001 by the MPU 2002 and output to the data processing circuit 1014 . As the image data, gradation data is used.
In FIG. 4A , eight addresses A(x−1,y−1), A(x,y−1), A(x+1,y−1), A(x−1,y), A(x+1,y), A(x−1,y+1), A(x,y+1), and A(x+1,y+1) around the address A(x,y) in the pixels 1004 are generated. Therefore, in FIG. 4B , image data D(x−1,y−1), D(x,y−1), D(x+1,y−1), D(x−1,y), D(x+1,y), D(x−1,y+1), D(x,y+1), and D(x+1,y+1) corresponding to these addresses A(x,y) are sequentially read out from the memory device 2001 and output to the data processing circuit 1014 . In the data processing circuit 1014 , these image data D(x,y) are-sequentially added. The added result is divided by nine corresponding to the total number of the image data D, to obtain the averaged image data D′(x,y) of the address A(x,y).
When a write signal is input from the memory device control circuit 1013 to the memory device 2001 , through the address buffers 1018 and address buses 1019 , the address A(x,y) is input from the address holding circuit 1016 to the memory device 2001 and stored. At the same time, through the data buses 1022 , the averaged image data D′(x,y) is input from the data processing circuit 1014 to the memory device 2001 and stored.
The above processing is performed for the pixels 1004 with respect to addresses A( 2 , 2 ) to A(N−1,M−1), as shown in FIG. 6 , to mask-process the entire image.
In order to perform the algorithm of FIG. 3 , the memory device control circuit 1013 is set to be a read state and input and output of the bidirectional buffers 1021 may be changed by the input and output control circuit 1017 .
In this algorithm, the image data D(x,y) is averaged simply. However, the image data D(x,y) may be weighted. FIG. 5 shows an algorithm for weighting the image data D(x,y) to enhance the averaged image data D′(x,y).
The address A(x,y) determined by the coordinate converting circuit 1015 is stored in the address holding circuit 1016 and output to the memory device 2001 through the address buffers 1018 and the address buses 1019 at the same time. The image data D(x,y) is read out from the memory device 2001 by the MPU 2002 and output to the data processing circuit 1014 . In the data processing circuit 1014 , the weighted image data D(x,y) is obtained by multiplying the image data D(x,y) by eight representing the total number of image data D(x,y) to be added later.
In FIG. 4A , eight addresses A(x−1,y−1), A(x,y−1), A(x+1,y−1), A(x−1,y), A(x+1,y), A(x−1,y+1), A(x,y+1), and A(x+1,y+1) around the address A(x,y) in the pixels 1004 are generated. Therefore, in FIG. 4B , image data D(x−1,y−1), D(x,y−1), D(x+1,y−1), D(x−1,y), D(x+1,y), D(x−1,y+1), D(x,y+1), and D(x+1,y+1) corresponding to these addresses A(x,y) are sequentially read out from the memory device 2001 and output to the data processing circuit 1014 . In the data processing circuit 1014 , these image data D(x,y) are sequentially added to the weighted image data D(x,y). The result is divided by sixteen, to obtain the averaged image data D′(x,y) of the address A(x,y).
Embodiment 2
In Embodiment 1, only one external memory device is provided in the active matrix panel 1001 . In this case, since original image data is overwritten, a mask-processing result cannot be confirmed. Therefore, in Embodiment 2, two external memory devices are provided outside the active matrix panel 1001 , so that image data before and after mask processing are stored.
FIG. 7 shows a display system of Embodiment 2. The active matrix panel is the same structure as that in Embodiment 1. Two memory devices 7001 and 7002 for storing image data and an MPU 7003 for controlling the entire system are provided outside the active matrix panel 1001 . The outputs of the active matrix panel 1001 and the MPU 7003 are connected to the memory devices 7001 and 7002 through address buses 1019 . Through the data buses 1022 , the active matrix panel 1001 , the memory devices 7001 and 7002 , and the MPU 7003 are connected each other to input and output a signal (data). The data buses 1022 are connected to a D/A converter 7004 which is connected to the active matrix panel 1001 through the video signal line 1008 . The memory device control line 7005 connects with the active matrix panel 1001 , the memory devices 7001 and 7002 , and the MPU 7003 each other. Through a control signal line 7006 , the active matrix panel 1001 is connected to the MPU 7003 .
In mask processing, the algorithm of FIG. 3 or 5 is used. Image data stored in the memory device 7001 is mask-processed, and then the mask-processed image data is stored in the memory device 7002 .
Embodiment 3
In Embodiments 1 and 2, examples of mask processing for the entire image are described. In Embodiment 3, in order to further shorten the processing time, mask processing is not performed for an area which is not necessary to mask-process.
FIG. 11 shows an active matrix panel of the embodiment. The active matrix panel is the same structure as that in FIG. 1 except for a circuit for designating an address of a pixel. In FIG. 11 , the outputs of an X-direction mask processing start/end signal line 11001 , a Y-direction mask processing start/end signal line 11002 , and a mask processing start signal line 11003 are connected to a subtraction circuit 11004 . The output of the subtraction circuit 11004 is connected to the X- and Y-coordinate counter circuits 1011 and 1012 and the coordinate converting circuit 1015 . The subtraction circuit 11004 and a coordinate value generating circuit 11005 are formed by a P-type, an N-type, or a complementary type MOS TFT, or a thin film diode of MIM (metal-insulator metal), NIN, PIP, PIN, NIP or the like.
The active matrix panel has, as similar to Embodiment 1, N×M pixels (N is the number of X-direction pixels and M is the number of Y-direction pixels). In the following symbols i, j, k, and 1, the relationships 1<i, k<N, 1<j, and 1<M is set.
In mask processing, a mask processing start signal is input from the mask processing start signal line 11003 to the substraction circuit 11004 . Also, From the X- and Y-direction mask processing start/end signal lines 11001 and 11002 , a start coordinate (i,j) and an end coordinate (k,l) which are mask-processed are input to the subtraction circuit 11004 . In the subtraction circuit 11004 , an X-direction counter end value (p=k−l+1) and a Y-direction counter end value (q=l−j+1) are calculated, so that control is performed to reset the counter value of the X-coordinate counter circuit 1011 by using a p-value and to reset the counter value of the Y-coordinate counter circuit 1012 by using a q-value. Therefore, the X-coordinate counter circuit 1011 is a p-coded (including binary, decimal or the like) counter circuit, and the Y-coordinate counter circuit 1012 is a q-coded (including binary, decimal or the like) counter circuit.
In the coordinate generating circuit 11005 , addresses (i+X-coordinate counter value, j+Y-coordinate counter value) are calculated to generate the addresses A(x,y) representing an area to be mask-processed. The algorithm of Embodiment 1 is executed for the pixels 1004 corresponding to the generated addresses A(x,y), so that mask processing is performed for only an area of FIG. 10 in the pixels 1004 .
In the embodiment, in order to store image data before and after mask processing, as shown in Embodiment 2, two or more memory devices may be provided.
As described above, by the present invention, in an active matrix panel formed by TFTs or the like, a circuit having a logic function such as data processing is formed by TFTs or the like on the same substrate. Therefore, without increasing a processing time of a MPU, image processing such as noise removal can be performed at a high speed. Also, miniaturization of a system can be realized. | In an active matrix panel, a pixel matrix which includes a plurality of gate lines, a plurality of source lines, and thin film transistors is formed on a first transparent substrate. A second transparent substrate is formed opposite to the first transparent substrate. A liquid crystal material is disposed between the first and second transparent substrates. A gate line driver circuit and a source line driver circuit are formed by a P-type, an N-type, a complementary type thin film transistors (including silicon film) or the like on the first transparent substrate. Also, a data processing circuit for performing mask processing or the like is formed by the thin film transistors or the like on the first transparent substrate. | 6 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a refrigerant composition which is suitable for an ultralow-temperature refrigerator using a non-azeotropic mixed refrigerant and is free of a possibility of causing depletion of the ozone layer.
[0003] 2. Description of the Related Art
[0004] Heretofore, a refrigerator using a non-azeotropic mixed refrigerant achieves ultralow temperatures by condensing refrigerants having lower boiling points in succession by evaporation of refrigerants having higher boiling points and a low-temperature refrigerant returning from the last evaporator so as to evaporate a refrigerant having the lowest boiling point at the end.
[0005] The present inventor has proposed examples of such a refrigerator and a refrigerant composition in Japanese Patent Publication No. 55944/1994.
[0006] However, since the refrigerant uses HCFC, it may cause depletion of the ozone layer.
[0007] Accordingly, the development of an alternate refrigerant composition which is free from a possibility of causing depletion of the ozone layer and capable of maintaining the performance of a conventional refrigerating circuit without modifying the circuit is desired.
[0008] Under the circumstances, the present applicant has proposed a refrigerant composition comprising R600 (n-butane: H 3 CH 2 CH 2 CH 3 ), R125 (CHF 2 CF 3 ), R23 (trifluoromethane: CHF 3 ) and R14 (tetrafluoromethane: CF 4 ) in Japanese Patent Application No. 526882/2001. However, since this refrigerant composition uses R600 which is combustible, it may burn upon leakage. It is better to avoid use of a combustible material on as many occasions as possible.
[0009] The present invention provides a refrigerant composition which hardly burns upon leakage and is free from a possibility of causing depletion of the ozone layer, and a refrigerating circuit using the refrigerant composition.
SUMMARY OF THE INVENTION
[0010] A refrigerant composition of the present invention comprises R245fa (CF 3 CH 2 CHF 2 ), R125 (CHF 2 CF 3 ), R23 (trifluoromethane: CHF 3 ) and R14 (tetrafluoromethane: CF 4 )
[0011] Further, a refrigerant composition of the present invention comprises R245fa (CF 3 CH 2 CHF 2 ), R125 (CHF 2 CF 3 ), R508A (R23/R116:39/61) or R 508 B (R23/R116:46/54) and R14 (tetrafluoromethane: CF 4 ).
[0012] Further, the refrigerant composition of the present invention is prepared by mixing 17.4 to 50 wt % of R245fa (CF 3 CH 2 CHF 2 ), 12 to 25 wt % of R125, 13.2 to 36.4 wt % of R508A (R23/R116:39/61) or R508B, and 13.2 to 36.4 wt % of R14.
[0013] Further, the refrigerant composition of the present invention further comprises 0.1 to 12 wt % of n-pentane.
[0014] In addition, a refrigerating circuit of the present invention is a single ultralow-temperature system which substantially comprises a condenser, an evaporator, a compressor, and heat exchangers and gas-liquid separators disposed in a multi-stage manner, wherein any of the above non-azeotropic mixed refrigerant compositions is used.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] [0015]FIG. 1 is a diagram for illustrating a refrigerant circuit of the present invention.
[0016] [0016]FIG. 2 is a diagram for illustrating the performance of this embodiment.
[0017] [0017]FIG. 3 is a diagram for illustrating the proportions of constituents used in this refrigerant composition.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0018] A first embodiment of the present invention will be described with reference to FIG. 1.
[0019] [0019]FIG. 1 shows a refrigerant circuit using a non-azeotropic mixed refrigerant comprising R245fa, R125, R508A and R14.
[0020] A pipe ( 2 ) on the outlet side of a compressor ( 1 ) passes through a condenser ( 3 ) and a frame pipe ( 20 ) and is connected to an oil cooler ( 4 ) of the compressor ( 1 ).
[0021] Coming out of the oil cooler ( 4 ), the pipe passes through the condenser ( 3 ) again and is connected to a first gas-liquid separator ( 5 ).
[0022] A liquid phase pipe ( 6 ) which comes out of the first gas-liquid separator ( 5 ) is connected to a first capillary tube ( 7 ).
[0023] The first capillary tube ( 7 ) is connected to a first intermediate heat exchanger ( 8 ).
[0024] A gas phase pipe ( 9 ) which comes out of the first gas-liquid separator ( 5 ) passes through the first intermediate heat exchanger ( 8 ) and is connected to a second gas-liquid separator ( 10 ).
[0025] A liquid phase pipe ( 11 ) which comes out of the second gas-liquid separator ( 10 ) is connected to a second capillary tube ( 12 ) which is connected to a second intermediate heat exchanger ( 13 ).
[0026] A gas phase pipe ( 14 ) which comes out of the second gas-liquid separator ( 10 ) passes through the second intermediate heat exchanger ( 13 ) and a third intermediate heat exchanger ( 15 ) in succession and is then connected to a third capillary tube ( 16 ).
[0027] The third capillary tube ( 16 ) is connected to an evaporator ( 17 ).
[0028] A pipe ( 18 ) which comes out of the evaporator ( 17 ) is connected to the third intermediate heat exchanger ( 15 ) which is connected to the second intermediate heat exchanger ( 13 ). Then, the second intermediate heat exchanger ( 13 ) is connected to the first intermediate heat exchanger ( 8 ) which is then connected to a pipe ( 19 ) on the inlet side of the compressor ( 1 ).
[0029] This refrigerant circuit is filled with a non-azeotropic mixed refrigerant comprising R245fa, R125, R508A and R14. It is considered possible to use 508B in place of 508A.
[0030] As for the boiling points of the refrigerants at atmospheric pressure, the boiling point of R245fa is 14.9° C., that of R125 is −48.57° C., that of R508A is −85.7° C., and R14 is −127.85° C.
[0031] Further, as shown in FIG. 2, the proportions of the refrigerants used in the present embodiment are such that without n-pentane, R245fa is 37.4 wt %, R125 is 21.6 wt %, R508A is 19.8 wt %, and R14 is 21.2 wt %. A further addition of 5.8 wt % of n-pentane completes preparation of a refrigerant composition to be used.
[0032] Next, the operation of the refrigerant circuit will be described.
[0033] A high temperature/high pressure gaseous mixed refrigerant discharged from the compressor ( 1 ) flows into the compressor ( 3 ), radiates heat in the compressor ( 3 ), cools a lubricant oil of the compressor ( 1 ) in the oil cooler ( 4 ), and radiates heat in the compressor ( 3 ) again. R245fa and a large portion of R125 in the mixed refrigerant are liquefied and flow into the first gas-liquid separator ( 5 ).
[0034] Then, liquid R245fa and R125 flow into the liquid phase pipe ( 6 ), while a gaseous portion of R125, R508A and R14 flow into the gas phase pipe ( 9 ).
[0035] R245fa and R125 which have flown into the liquid phase pipe ( 6 ) are depressurized in the first capillary tube ( 7 ) and flow into the first intermediate heat exchanger ( 8 ) so as to evaporate therein.
[0036] The temperature of the first intermediate heat exchanger ( 8 ) is around −5.7° C. since a refrigerant returning from the evaporator ( 17 ) flows thereinto.
[0037] Meanwhile, of R125, R508A and R14 which have flown into the gas phase pipe ( 9 ), R125 and a portion of R508A are cooled by R245fa and R125 which evaporate in the first intermediate heat exchanger ( 8 ) and the refrigerant returning from the evaporator ( 17 ) so as to be condensed and liquefied while passing through the first intermediate heat exchanger ( 8 ) and then flow into the second gas-liquid separator ( 10 ).
[0038] Then, liquid R125 and R508A flow into the liquid phase pipe ( 11 ), while a gaseous portion of R508A and R14 flow into the gas phase pipe ( 14 ).
[0039] R125 and R508A which have flown into the liquid phase pipe ( 11 ) are depressurized in the second capillary tube ( 12 ) and flow into the second intermediate heat exchanger ( 13 ) so as to evaporate therein. The temperature of the second intermediate heat exchanger ( 13 ) is around −34.4° C. since a refrigerant returning from the evaporator ( 17 ) flows thereinto.
[0040] Meanwhile, of R508A and R14 which have flown into the gas phase pipe ( 14 ), R508A is cooled by R125 and R14 which evaporate in the second intermediate heat exchanger ( 13 ) and the refrigerant returning from the evaporator ( 17 ) so as to be condensed and liquefied while passing through the second intermediate heat exchanger ( 13 ) and then passes through the third gas-liquid separator ( 15 ).
[0041] The temperature of the third intermediate heat exchanger ( 15 ) is around −55.2° C. since a refrigerant coming right out of the evaporator ( 17 ) flows thereinto.
[0042] Hence, R14 which flows through the gas phase pipe ( 14 ) is condensed in the third intermediate heat exchanger ( 15 ). These liquefied R508A and R14 are depressurized in the third capillary tube ( 16 ) and flow into the evaporator ( 17 ) so as to evaporate therein, thereby cooling surroundings thereof.
[0043] At this time, the temperature of the evaporator ( 17 ) became an ultralow temperature of about −92.7° C. on average. By using the evaporator ( 17 ) for, e.g., cooling the inside of a freezer, the inside of the freezer could be cooled to about −91.5° C.
[0044] A refrigerant which has come out of the evaporator ( 17 ) flows through the intermediate heat exchangers ( 15 ), ( 13 ) and ( 8 ) in turn, merges with refrigerants evaporating in the exchangers, and then returns to the compressor ( 1 ) through the suction pipe ( 19 ).
[0045] The oil of the compressor ( 1 ) which circulates in the refrigerant circuit is returned to the compressor ( 1 ) in the state of being dissolved in R245fa.
[0046] Further, R245fa also serves to lower the discharge temperature of the compressor ( 1 ).
[0047] The performance of this refrigerating circuit is shown in FIG. 2.
[0048] The proportions of these refrigerants are not limited to those in the present embodiment. That is, it was confirmed by an experiment that an ultralow temperature of not higher than −90° C. could be obtained in the evaporator ( 17 ) by mixing 17.4 to 50 wt % of R245fa, 12 to 25 wt % of R125, 13.2 to 36.4 wt % of R508A or R508B, and 13.2 to 36.4 wt % of R14 (refer to FIG. 3).
[0049] Further, it was also confirmed that addition of 0.1 to 12 wt % of n-pentane to this refrigerant further improved recovery of oil.
[0050] In addition, similar ultralow temperatures can be obtained even if R23 (trifluoromethane, CHF 3 , boiling point: −82.1° C.) resulting from removing R116 from R508A is used in the above mixed refrigerant.
[0051] According to the present invention, the refrigerant has no possibility of causing depletion of the ozone layer, and since the refrigerant composition is noncombustible, possible combustion can be prevented even when it leaks. | The development of an alternate refrigerant composition which is free from a possibility of causing depletion of the ozone layer and capable of maintaining the performance of a conventional refrigerating circuit without modifying the circuit is desired. An object of the present invention is to provide such a refrigerant composition and a refrigerating circuit using the refrigerant composition. A refrigerant composition of the present invention comprises R245fa (CF 3 CH 2 CHF 2 ), R125 (CHF 2 CF 3 ), R508A (R23/R116:39/61) and R14 (tetrafluoromethane: CF 4 ). Thus, the refrigerant composition has no possibility of causing depletion of the ozone layer. Further, since the composition is noncombustible, possible combustion can be prevented even if it leaks. | 2 |
TECHNICAL FIELD
[0001] The invention relates to digital computing devices, particularly to systems and methods for encrypting data files to prevent theft and piracy.
CROSS REFERENCE TO RELATED APPLICATIONS
[0002] (Not applicable)
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0003] (Not applicable)
BACKGROUND OF THE INVENTION
[0004] Over the past decade, people have turned more and more to the Internet to purchase items. This is overwhelmingly the scenario when it comes to the purchase of music, movies, books and other multi-media entertainment. Today's computer users download many multi-media files through various computer-based multimedia applications such as iTunes®, Barnes & Noble's Nook®, Amazon's Kindle®, etc. The rise online purchases of music, etc., while certainly more convenient to consumers, has opened a whole new set of concerns for the owners of those works. The security of data files has become a very important issue to the owners and authors of digital works.
[0005] The theft of data files has led to the increase of data file security methods, among which, data file encryption is a widely used method. Data encryption involves taking the data file and encoding it so that only authorized parties can use the file by obtaining a “key’ to decrypt the data.
[0006] However, once a consumer downloads a data file and stores it on the hard drive of their computer, the consumer is able to access the file and strip the file of any protections the file may have. Therefore, the user can download a song file and then remove any digital protections on the file and then share the file with others freely. Thus, resulting in a loss of profit for the record label, Production Company, artist, etc. because the file will be available for free to people who normally have had to purchase the file in order to listen to it.
[0007] Therefore, a need exists for data file protection beyond the level of existing encryption methods. Particularly, a need exists to maintain the integrity of data file protection once the data file has be purchased by a consumer so as to prevent piracy of the data file.
SUMMARY OF THE INVENTION
[0008] The present invention discloses a method for encrypting and decrypting music files using the following steps: generating a first public digital key and a first private digital key; encrypting a music file with said first public key; uploading said first public key encrypted music files to a server; storing said first public key encrypted music files in said server; packaging said first private key into a database file in a downloadable computer application; downloading said downloadable computer application with said packaged first private key onto a computer device; connecting said computer application with said server via a web server and a computer operating system which communicate using HTTP; requesting, via said computer application, that said first public key encrypted music file stored on said server to be sent to said computer device; encrypting said first public key encrypted music file with a second public key by said web server; sending said first and second public key encrypted music file from said server to said computer operating system through said web server; decrypting said second public key by said operating system using a second private key obtained via said HTTP communication process; downloading said first public key encrypted music file to said computer device; storing said first public key encrypted music on said computer device; requesting to access said first public key encrypted music file stored on said computer device by said computer application; decrypting said first public key encrypted music file stored on said computer device using said first private key packaged into said computer application; storing said decrypted music file on said computer device while said computer application plays said decrypted music file; and then deleting said decrypted music file from said computer device once said computer application has completed playback of said decrypted music file.
BRIEF DESCRIPTION THE DRAWINGS
[0009] The operation of the invention will become apparent from the following description taken in conjunction with the drawings, in which:
[0010] FIG. 1 is an overview of a prior art method for downloading a data file to a computer device;
[0011] FIG. 2 is an overview of a prior art method for downloading a computer application to a computer device;
[0012] FIG. 3 is a flowchart of the inventive method for downloading a computer application to a computer device;
[0013] FIG. 4 is a flowchart of the inventive method for storing a data file on a server;
[0014] FIG. 5 is a flowchart of the inventive method for encrypting and transferring a data file from a remote server to a computer device;
[0015] FIG. 6 is a flowchart of the inventive method for playback of an encrypted data file on a computer device;
[0016] FIG. 7 is a flowchart of the development process of the inventive encryption system;
[0017] FIG. 8 is a flowchart of the user installation process of the inventive encryption system;
[0018] FIG. 9 is a flowchart of the inventive method for encrypting and transferring a data file; and
[0019] FIG. 10 is a flowchart of the inventive method for playback of an encrypted data file.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0020] Referring to FIG. 1 , an overview of the prior art method for downloading a data file is illustrated. In a typical download data file 50 would be stored on server 52 . Data file 50 can be any type of data file such as .mov, .mp4, .m4v, .mp3, .wav, .mpeg, .jpg, .png, .aef, .epub, .lrf, .lrx, .cbr, .cbz, .cb7, .cbt, .cba, .chm, DAISY, .html, .djvu, .azw, .lit, .exe, etc. Server 52 could be located anywhere in the world and would be associated with a particular website or computer application such as iTunes®, Netflix®, Kindle®, etc. Data file 50 would be transmitted from server 52 via communications network 54 , i.e. the Internet, to computer application 56 . Computer application 56 would be associated with server 52 . For example, computer application 56 might be iTunes®, and thus server 52 would be an iTunes® server. Once data file 50 has been transmitted to computer application 56 , a user would then be able to transfer data file 50 to the user's computer device 58 , such as a personal computer, laptop, tablet, or mobile phone, etc. Once data file 50 is transferred to the user's computer device 58 , the user would be able to use, transfer, copy, edit, etc. data file 50 however the user wanted.
[0021] Referring to FIG. 2 , an overview of the prior art method for downloading a computer application is illustrated. In a typical download computer application 60 would be stored on server 62 . Computer application 60 could be any type of application such as a music application, a electronic book application, a game application, or a utility application like a calculator, etc. Server 52 could be located anywhere in the world and would be associated with a particular website, application store or any other electronic means of purchasing a computer application. Computer application 60 would be transmitted from server 62 via communications network 64 , i.e. the Internet, to computer application network 66 . Computer application network 66 would be associated with server 62 . Once computer application 60 is transmitted to computer application network 66 it is then installed onto the disk drive of computer device 68 . Computer device 68 may be any type of computer device such as a personal computer, laptop, tablet, or mobile phone, etc. Once computer application 60 is installed on computer device 68 , a user would be able to access and use computer application 60 at any time on computer device 68 until the user uninstalls computer application 60 .
[0022] Referring now to FIG. 3 , an overview of the inventive method for providing an encrypted computer application is illustrated. In contrast to the prior art method illustrated in FIG. 2 and described above, the inventive system provides a user with a computer application using Pretty Good Privacy (PGP) data encryption. In a preferred embodiment of the present invention public-key cryptography or asymmetric cryptography is used, a method well known in the art. In the inventive method a computer application with an embedded private digital key that will allow the computer application to read data files encrypted with the corresponding public key is provided to a user. A private digital key 70 is written into the code of computer application 72 . Computer application 72 is then stored on server 74 . Once a user purchases computer application 74 , computer application 74 is transmitted via communications network 76 , i.e. the Internet, to computer application network 78 . Computer application network 78 may be a website or computer application store, such as iTunes. Once computer application 72 is transmitted to computer application network 78 , computer application 72 is then installed on computer device 80 . Computer device 80 may be any type of computer device such as a personal computer, laptop, tablet, or mobile phone, etc. Once computer application 72 is installed on computer device 80 , a user would be able to access and use computer application 72 at any time on computer device 80 until the user uninstalls computer application 72 . In contrast the prior art, computer application 72 remains embedded with a private digital key while installed on computer device 80 .
[0023] Once a user has installed computer application 72 with the private digital key embedded into the code of computer application 72 , the user will then be able to purchase and download data filed. Referring now to FIG. 4 , a simple overview of data file storage is illustrated. All data files to be stored on the inventive systems servers will be encrypted with a public key, which corresponds to the private digital key coded in computer application 72 . Data file 71 , which can be any file type such as a .mov, .mp4, .m4v, .mp3, .wav, .mpeg, .jpg, .png, .aef, .epub, .lrf, .lrx, .cbr, .cbz, .cb7, .cbt, .cba, .chm, DAISY, .html, .djvu, .azw, .lit, .exe, etc., is encrypted with a public encryption key 73 . Once data file 71 has been encrypted with public encryption key 73 , data file 71 is then stored on server 74 . Server 74 may store a wide variety of data file types, a few different types of data files, or a single type of data file, such as an audio file. Server 74 may also store a library of different data files.
[0024] Once a user has installed computer application 72 , the user will be able to purchase and download data files from server 74 to computer application 72 and then use the data files on the user's computer device. FIG. 5 illustrates the inventive method of downloading an encrypted data file such that the data file is stored in a computer application database in encrypted format until selected by the user. Thus, the inventive system and method provides a user with access to data files without storing those data files on the user's computer device. The primary purpose for this is to prevent theft and piracy of the data file by the user. Through the inventive system, the user will not be able to save the data file to the user's computer device and strip the data file of it protections so that the user can use, copy, edit, etc. the data file.
[0025] Referring to FIG. 5 , the above method is illustrated. A user on computer device 80 will open computer application 72 . Computer application 72 is encrypted with a private digital key as described above and illustrated in FIG. 3 . Once a user has opened computer application 72 , the user will be able to download a data file through purchase of the data file. Once the user has purchased a data file, computer application 72 will generate an authorization request 82 . Authorization request 82 will be sent to computer operating system 84 . This authorization request 82 will ask computer operating system 84 to connect with web server 88 via a secure connection such as hypertext transfer protocol secure (HTTPS). Computer operating system 84 will then generate a digital certificate 86 . Digital certificate 86 will then be sent to web server 88 . Once web server 88 has received digital certificate 86 , web server 88 will either send a digital certificate 86 back to computer operating system 84 or send terminate signal 90 .
[0026] If web server 88 proceeds to exchange digital certificates 86 with computer operating system 84 , web server 88 will then transmit file request 92 to server 74 . Server 74 , upon receipt of file request 92 , will then obtain authorized data file 71 from its database and transmit data file 71 back to web server 88 . Web server 88 will then encrypt the data file with public key 94 of computer operating system 84 . The data file will then be transmitted to computer operating system 84 via a secure pipeline created by the exchange of digital certificates 86 . Once computer operating system 84 receives the now double-encrypted data file, encrypted once as illustrated in FIG. 4 and then again by web server 88 with public key 94 , computer operating system 84 will then decrypt the data file with the private key 96 of computer operating system 84 .
[0027] Once the data file has been decrypted by private key 96 of computer operating system 84 the system may proceed in one of two ways. In the preferred embodiment, the data file is encrypted a third time by operating system 84 , so as to prevent other computer applications resident on computer device 80 from accessing the data file. Once the data file has been encrypted for the third time, the data file is then transmitted to computer application 72 , which then stores the data file in computer application database 100 .
[0028] After a user has downloaded encrypted data files from the server to the computer application database, the user will then be able to access the data file. However, the user will not have the same access to the file as the user would had he simply downloaded an un-encrypted data file. The encryption will limit what the user will be able to do with the data file. In a preferred embodiment of the present invention, audio files will be downloaded via the inventive system. The user will then be able to listen to these encrypted audio files on the user's computer device. However, the audio files will remain on the user's computer device once the audio file has ended.
[0029] Referring now to FIG. 6 , the inventive method of encrypted data file playback is illustrated. A user on computer device 80 opens computer application 72 . The user will then select which data file the user wants to access from the computer application database. The data file is then decrypted by private digital key 102 resulting in un-encrypted data file 104 . Un-encrypted data file 104 is then transmitted to computer operating system disk drive 106 where the user is able to play, read, watch, and/or listen to the data file. Once un-encrypted data file 104 has finished, it is deleted from computer operating system disk drive 106 . Thus, all that remains is the encrypted data file resident in the computer application database.
[0030] The development process of the inventive system is illustrated in FIG. 7 . At step 300 , a public digital key 305 and a private digital key 306 are generated that is specific to the inventive system. Public digital key 306 and private digital key 305 are used in tandem so that only the private digital 305 can decrypt data filed encrypted with the public digital key 306 . Public digital key 306 encrypts a data file 340 at steps 350 producing an encrypted data file 360 . FIG. 7 illustrates the process for a mp3 file, but any data file may be encrypted for use in the inventive system. Encrypted data file 260 can then be uploaded the inventive systems servers where is it will be stored on a disk drive. Private digital key 305 is packaged into a the inventive downloadable computer application 310 within a database file, which allows only for the downloadable computer application to access private digital key 305 . Further protection of the private digital key is provided for by a computer operating system, which does not allow other computer applications to access the files of inventive downloadable computer application 310 . Inventive downloadable application 310 will be available to users download to computer devices from computer applications store 330 such as the Apple® App Store®.
[0031] FIG. 8 illustrates the installation process for the inventive downloadable computer application. The inventive downloadable computer application with private key 405 is stored on a computer applications store server 400 . At step 420 , a user searches for downloadable computer application with private key 405 on their computer device via the Internet 410 . Alternatively, a user may follow a unique URL link to downloadable computer application with private key 405 within computer applications store. A user will then download to his/her computer device downloadable computer application with private key 405 at step 430 . Downloadable computer application with private key 405 will be downloaded on the user's computer device via the Internet from the computer application store server 400 . Once downloaded to user's computer device, downloadable computer application with private key 405 will be installed on the computer device automatically by the operating system of the computer device.
[0032] FIG. 9 illustrates the preferred embodiment of the inventive method and system. The user launches downloadable computer application with private key 450 , which will then make an authentication request to a server to download the entitled data files. All network requests will leverage a computer operating system communication. Downloadable computer application with private key 450 will pass a pre-packaged URL at step 460 to a computer operating system to establish a connection. The operating system will to connect to web server 505 via HTTPS to establish a secure connection at step 460 . This will be the standard HTTPS communication process. The operating system will connect to web server 505 running in a datacenter. Web server 505 has software called Apache Web Server running on port 443 . The operating system and Apache Web Server will exchange their digital certificates which include a public key. This is a different set of public/private key (second pair of keys) than the originally generated public/private generated by the inventive system as illustrated in FIG. 7 . Once the digital certificates have been exchanged, there will be a secure channel established between the operating system and Apache Web Server. Any information passed between the two computers will be encrypted by their respective public key. For example, if data is passed from the operating system to Apache, then the operating system will encrypt the data with Apache's public key. Once the data reaches Apache, Apache will use its own private key to decrypt the data. Apache Web Server will make a request to the file server 495 to get a specificed encrypted data file 500 . File server 495 will retrieve the file from the computer's disk drive and return encrypted data file 500 to Apache Web Server. Apache Web Server will take encrypted data file 500 and will add another level of encryption using the operating system's public key. The output of the file will be a double encrypted file. The first level of encryption being the inventive downloadable computer application's public key and the second level of encryption being the operating system's public key. Encrypted data file 500 is transported from Apache to the operating system via the Internet. Once the file has been received by the operating system, the operating system will decrypt the file using the operating system's private key. The output will be the original encrypted data file 500 . Encrypted data file 500 will be passed to the inventive downloadable computer application. The encrypted data file will be stored on the operating system device as an encrypted file. The operating system protects encrypted data file 500 by restricting any other operating system applications on the computer device from accessing each other's files.
[0033] FIG. 10 illustrates the method playback of an encrypted data file within the inventive system. During playback, the encrypted data file will be decrypted using private key at step 550 . Private key 550 will be bundled with the a downloadable computer application and stored securely in a protected database. The decrypted data file will be stored on the operating system device's disk drive during playback. Once playback has been completed, the decrypted data file will be deleted from the disk drive.
[0034] While illustrative embodiments of the invention have been described, it is noted that various modifications will be apparent to those of ordinary skill in the art in view of the above description and drawings. Such modifications are within the scope of the invention which is limited and defined only by the following claims. | A method and system for data file encryption and decryption using multiple public and private digital keys wherein no fully decrypted data files are stored on a computer device. | 7 |
FIELD OF THE INVENTION
[0001] The present invention includes a photolithographic process for printing integrated circuit structures on the surface of a substrate.
BACKGROUND OF THE INVENTION
[0002] Photolithography is widely used to form patterns on semiconductor wafers during fabrication of integrated circuits. A semiconductor wafer 110 (FIG. 1) including an optional topmost layer 115 is coated with a photoresist layer 120 . Photoresist 120 is irradiated from a light source 130 through an annular aperture 160 . A mask or reticle 140 is placed between source 130 and photoresist 120 . Binary mask 140 carries a pattern consisting of opaque and clear features. This pattern defines which areas of photoresist 120 are exposed to the light from source 130 . After the exposure, the photoresist 120 is developed so that some of the photoresist is removed to uncover the underlying surface of layer 115 on substrate 110 . If the photoresist is “positive,” then the photoresist is removed where it was exposed to the light. If the photoresist is “negative,” the photoresist is removed where it was not exposed. In either case, the remaining photoresist and the exposed (uncovered) areas of substrate 110 reproduce the pattern on mask 140 . The wafer is then processed as desired (e.g., the exposed areas of layer 115 and/or substrate 110 can be, for example etched, coated, plated, or implanted with a dopant, among other possibilities.)
[0003] There is a trend in the semiconductor industry to have ever smaller feature sizes, while at the same time there is a desire to use existing photolithography equipment for new generations of semiconductors. In general, the minimum feature width of the patterned area is limited by the wavelength of the particular light source used, due to diffraction effects. That is, light diffracts around the edges of an aperture, so that the rays spread out from the source before being incident on the substrate. Therefore, the feature dimensions become poorly defined, when the aperture is smaller than, or on the order of, the wavelength of the light used to illuminate the pattern.
[0004] A number of techniques exist for improving the shape of the edge features which determine the minimum feature dimension which a particular light source is capable of creating on the substrate. One technique involves using a half-tone mask, which employs areas which are partially transmissive, to create destructive interference at the boundaries of the illuminated feature. The interference causes a sharpening of the feature boundary, compared to what its shape would be using a binary mask, that is, one with areas that are either fully transmissive or fully opaque. Half-tone masks, however, are about twice as expensive as binary masks.
[0005] Accordingly, because of the need to create ever smaller integrated circuit (IC) devices, a method that can further reduce the feature size that can be made by a given light source on a substrate would be of great commercial benefit.
SUMMARY
[0006] Embodiments of the invention involve, among other things, double-exposing a photoresist mask and substrate to an incident radiation source (e.g., a light source). The first exposure is applied with an incident energy which is sufficient to convert the upper portion of the photoresist to its transparent state, but not in the lower portion of the photoresist, as the intensity drops to below an energy threshold deeper in the film. A second, subsequent exposure, defines the final aperture in the film, and is narrower than the initial, latent print of the light on the film made by the first exposure. The second exposure defines a narrower region because it traverses the latent image made by the first exposure, which is a cone-shaped feature made in the film, in which the inner portion of the cone has been converted to its transparent state. Therefore, inner portions of the second beam, which traverse the transparent portion of the cone, are attenuated less effectively than outer portions of the second beam, and therefore maintain the threshold intensity required to convert a corresponding inner portion of the photoresist to its transparent state. The outer portions of the second beam, which are more attenuated, gradually fail to convert the photoresist. A net result is a feature in the photoresist that is smaller than what normally could be produced using the light source.
[0007] The embodiments may also include the use of two photoresist baking steps in addition to the two exposure steps in the photoresist processing. The first baking step takes place after the first exposure, and the second baking step takes place after the second exposure. The two baking steps evaporate moisture from the film, causing the film to shrink slightly, and activate a photo acid generator (PAG) in the photoresist film. The thinner remaining film may require less incident light intensity in the second exposure to convert the photoresist, and the aperture in the photoresist may be widened slightly by the activation of the PAG. Because the photoresist film is thinner, it attenuates a smaller proportion of the incident light beam throughout its depth. Therefore, the variability of the incident energy, as a function of depth in the photoresist film, is narrower. As thinner films may have a smaller variability than thicker films, they may result in a wider process window. A wider process window is important in designing a capable process, which generates repeatable results in the face of some variability in input parameters.
[0008] The embodiments may include use of a binary bias mask during one or both of the exposure steps, whose features have a wider diameter than the eventual feature size on the surface of the photoresist. The bias mask allows an area to be illuminated which is larger than the eventual feature size. Therefore, the bias mask may allow some misregistration of the wafer in the second exposure, compared to its position in the first exposure, as a process tolerance for the double exposure procedure.
[0009] These and other features of the present invention will be illustrated further by the following detailed description, and the accompanying drawings of the exemplary embodiments.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] [0010]FIG. 1 is a side view of a photoresist exposure system suitable for some embodiments of the present invention.
[0011] [0011]FIG. 2 shows a simplified flow chart of an exemplary process according to this invention.
[0012] [0012]FIG. 3 a is a cross-sectional side view of the photoresist after a first exposure step, and FIG. 3 b is a cross-sectional side view of the photoresist after a second exposure step. FIG. 3 c is a top plan view of the photoresist of FIG. 3 b.
[0013] [0013]FIG. 4 a shows data taken on a wafer, with a double exposure/double bake photoresist process applied. FIG. 4 b shows data taken on a wafer, with a single exposure/single bake process applied.
[0014] [0014]FIG. 5 shows data taken on a wafer, with a single exposure/double bake photoresist process applied.
[0015] [0015]FIG. 6 shows data taken on a wafer, with a double exposure/double bake photoresist process applied, according to the present invention.
DETAILED DESCRIPTION
[0016] The schematic diagram shown in FIG. 1 shows elements of an exemplary photolithography apparatus 100 suitable for practicing the invention. The apparatus includes an illumination source 130 , a binary mask 140 , an adjustable stage 170 for holding a substrate 110 , a 4× reduction lens 150 , and an annular aperture 160 . The 4× reduction lens 150 is included which will project an image of the binary mask 140 on a layer of photoresist 120 deposited on the substrate 110 . The projected image is, in this example, four times smaller than the physical features in the binary mask 140 .
[0017] The annular aperture 160 blocks the center of an illumination beam from the illumination source 130 , while allowing the outer ring diameter of the beam to pass. This is done because the outer portions of the incident beam are more collimated than the inner portions, and therefore they can be focused more effectively. Using the more collimated outer portion of the beam reduces the feature size that the beam can create. For example, in the present embodiment the annular aperture is 0.8 outer /0.5 inner , where 0.8 outer refers to the diameter of the outer (transparent) ring of the annular aperture and 0.5 inner refers to the diameter of the inner (opaque) ring of the annular aperture. Since the inner ring is opaque, this annular aperture 160 blocks ⅝ of the incident light in this embodiment.
[0018] The substrate 110 in FIG. 1, which may be a bare semiconductor wafer, or as shown may have a topmost layer 115 , which is subjected to the process of FIG. 2. Topmost layer 115 may be a conductive or insulative layer. A second layer of anti-reflective coating 125 is deposited on topmost layer 115 , followed by a layer of photoresist 120 . The photoresist layer 120 will be patterned and processed, to form a photoresist mask, which will be used to further process the first layer 115 and/or substrate 110 , by, for example, etching, deposition, plating or ion implantation.
[0019] The lithographic processing that will be applied to the substrate 110 , is shown in the simplified flow chart of FIG. 2. In this process, a photoresist mask, including holes for forming contacts in semiconductor substrate 110 is produced. However, as will be apparent to those skilled in the art, the method of FIG. 2 can be applied to other shapes and patterns to be produced on a photoresist mask. Substrate 110 is prepared by initially depositing a layer of anti-reflective coating, followed by depositing 15 the layer of photoresist. The photoresist is then exposed (step 20 ) to incident radiation at an energy less than the minimum threshold energy. The minimum threshold energy is defined as the radiation dose needed to “convert” a pattern in the photoresist, that is to render the photoresist material transparent and/or soluble in the developing process.
[0020] The first exposure step 20 is followed by a first baking step 30 , which activates PAG in the photoresist film. The PAG will promote the solubility of the photoresist when exposed to a solvent in the developing step. The next event is a second exposure (step 40 ) of the photoresist to the incident radiation, at an energy density greater than or equal to the difference between the threshold required for converting the photoresist to its transparent state, and the energy applied in the first exposure. The second exposure step 40 is followed by a second bake (step 50 ). After the second baking step 50 , the photoresist is developed (step 60 ) using a solvent to dissolve the areas which have been converted to their soluble state by exposure to the incident radiation. The developing step 60 is followed by further downstream processing steps 70 , (e.g., etching, deposition, plating, implantation) to produce the desired device.
[0021] In an exemplary process embodiment of FIG. 2, the topmost layer of the substrate 110 is coated with a 0.078 μm thick layer of AR2 anti-reflection coating manufactured by Shipley, LLC of Marlborough, Mass., and a 0.540 μm thick layer of UV6 (deep ultra-violet photoresist) also manufactured by Shipley LLC. UV6 is a positive photoresist, so that the exposed areas are removed in the developing process. However, as will be clear to those skilled in the art, a negative photoresist may also be used.
[0022] In the exemplary embodiment of FIG. 2, first exposure step 20 is done through binary mask 140 , which has features which are either fully transparent or fully opaque. The features in the binary mask 140 are also larger than the eventual feature size to be created in the photoresist 120 . The features in the binary mask 140 are then imaged onto the surface of the photoresist 120 using the 4× reduction lens 150 . For example, in this exemplary embodiment, a 60 mn binary bias mask is used. That is, the binary mask 140 has 880 nm features which are either fully transparent or fully opaque. These 880 nm features translate to 220 nm features at the wafer surface, after projection through the 4×-reduction lens 150 . Thus, a mask 140 is used with a 60 mn bias, that is, the openings are 60 nm larger (220 mn) than the eventual dimensions of the features on the photoresist, which will be 0.16 μm (220 nm−60 mn=160 mn). The purpose of the larger featured binary mask 140 , is to provide a tolerance range for the repositioning of the wafer after it has been removed for baking. Therefore, even if there is a slight misalignment of the wafer with respect to its position during the first exposure, the misalignment is likely to fall within the tolerance allowed by the 60 nm binary mask.
[0023] The use of a binary mask in this embodiment yields a significant cost savings, as binary masks cost approximately half as much as half tone masks or phase shift masks used in the prior art to create such small features.
[0024] The exposure of the photoresist 120 on the substrate 110 in both first exposure step 20 and second exposure step 40 will be performed using an energy density from light source 130 which is less than the threshold energy required to convert the photoresist 120 to its transparent state. In one embodiment, the exposure is performed using an ultra-violet radiation source 130 , e.g. a 248 nm source, such as that provided by a scanner of the type ASML 500 available from manufacturer ASML Holding NV of Veldhoven, The Netherlands. For the type of photoresist described above, the radiation dose suggested by ASML to be applied may be 27.5 mj/cm 2 . The dosage for the first exposure step 20 is less than, e.g. approximately 62% of, the suggested dosage recommended by the manufacturer. This dosage is less than the threshold required to convert the photoresist to its transparent state in a single exposure. In other embodiments, the incident energy for the first exposure step 20 may be anywhere in the range of about 50%-80%, or at least 20% less than that required to convert the photoresist in a single exposure.
[0025] Therefore, for the first exposing step, the incident energy may be about 17 mj/cm 2 (62% of 27.5 mj/cm 2 ) and the focal spot may be slightly above (e.g. about 0.1 μm above) the true focal point of the beam. The focal spot is the difference in elevation of the wafer on the adjustable stage 170 with respect to its true focal point. The focal spot can be varied in 0.1 μm increments, by the adjustable stage 170 upon which the wafer is mounted. Therefore, for this first step, the incident energy may be about 62% or about ⅔ of the recommended dose energy, and the elevation may be 0.1 μm above the true focal spot.
[0026] A purpose of the first exposure step 20 of FIG. 2 is to irradiate a cone-shaped image on the photoresist 120 , wherein the cone has absorbed sufficient energy to convert the top layers of the photoresist 120 . The situation is shown diagrammatically in FIG. 3 a, which is a cross-sectional side view of the photoresist after a first exposure step 20 . The cone-shaped region 200 of the first exposure 20 results from the shadowing effects of the edges of the aperture on the transmitted beam, which means that the maximum beam intensity occurs somewhere near the center of the beam, and the outer edges of the beam are partially obscured by the edges of the mask aperture. Therefore, the portions of the photoresist near the center of the beam reach the threshold intensity required to convert the photoresist, before the outer diameters of the beam. For this reason, the first exposure 20 leaves a latent image in the photoresist, of a roughly cone-shaped region 200 which has been exposed to sufficient energy to become transparent. However, the region 200 does not extend through the bottom of the photoresist 120 , but only to an intermediate level indicated by reference number 220 , so that the material at the bottom of the photoresist remains unconverted. If the photoresist were to be developed at this point in processing, an aperture 205 , shown in FIG. 3 c, would be formed in the top of the photoresist layer, however there would be no aperture at the bottom of the film, because the converted region 200 does not extend to the bottom of the film. The diameter of top aperture 205 of may be determined by the width of the beam transmitted through the binary mask, which at the wafer surface may be about 0.22 μm wide.
[0027] Returning to FIG. 2, the substrate 110 and photoresist 120 are baked in step 30 for 90 seconds at between 110° C. and 140° C., e.g. at 130° C. Baking activates the PAG in the photoresist which promotes the solubility of the photoresist during the developing process. The photoresist may shrink during the baking, by releasing moisture to the environment. The shrinkage may help to reduce the thickness of the remaining unexposed layers of photoresist for subsequent exposures.
[0028] The substrate 110 is then reinserted into the photolithography chamber, and is readjusted using stage 170 to be within a certain tolerance, generally within 20-45 nm of the original focal spot. The wafer is then illuminated for the second time in step 40 of FIG. 2, with another 17 mj/cm 2 of incident energy. Again, this dosage is less than the amount required to convert the photoresist to its transparent state, in a single exposure.
[0029] [0029]FIGS. 3 a - 3 c illustrate the effects of the double exposure process on the photoresist 120 . FIGS. 3 a illustrates the first exposure step 20 , and FIG. 3 b is a cross-sectional side view of the photoresist after a second exposure 40 of the photoresist 120 . To clear the lower regions of the photoresist requires the second exposure step 40 , which forms a second, inner region 210 shown in FIG. 3 b. The second exposure roughly overlaps the first, within some tolerance, and again the outer diameters of the beam may contain less energy than the inner diameters because of the shadowing effects of the mask on the beam. However for the second, inner region 210 , the beam energy profile may be further convolved with the cone-shaped outer region 200 (FIG. 3 a ) left by the first exposure step 20 , because the center rays of the beam in the second exposure may traverse mainly transparent photoresist material left by the first exposure, near the center of the cone. Upon developing the photoresist, the clear areas will be dissolved and leave an aperture at the top 205 and the bottom 215 of the photoresist, as shown in the top plan view of FIG. 3 c. Therefore, upon reaching the target depth for the aperture, the center of the irradiating beam may have undergone less attenuation and may therefore achieve the threshold energy more readily than the outer portions. Therefore, the diameter of the aperture at the bottom 215 of the converted area in the photoresist is smaller than the aperture at the top 205 of the photoresist, and smaller than what could conventionally be produced using the same radiation source.
[0030] The second, inner region 210 , therefore, may define the bottom aperture 215 of the contact with a diameter that is narrower than the top aperture 205 in the photoresist. The second, inner region 210 of the second exposure 40 has received approximately 120% of the required dosage to convert the photoresist, whereas the cone-shaped outer region 200 of the first exposure 20 has received only approximately 62% of the required dosage. Therefore, the second exposure may define the eventual 0.16 μm aperture 215 at the bottom of the contact.
[0031] [0031]FIGS. 3 a - 3 c also demonstrate why the thickness of the photoresist is a factor in determining the final width of the aperture 215 created by the photoresist mask 140 . Because of the finite cone angle of the second, inner region 210 in the photoresist 120 , the top aperture 205 in the top of the photoresist is in general wider than the bottom aperture 215 created in the bottom of the photoresist. Therefore the aperture size at the bottom aperture 215 of the photoresist film may be a function of its thickness. Reducing the thickness of the film may reduce the variability in the final aperture size. Therefore, thinner films may have a smaller variability than thicker films, and result in a wider process window.
[0032] Returning to FIG. 2, in step 50 , the photoresist film is baked a second time. This second baking step may be performed at 110° C.-140° C., e.g. 130° C., for 60-90 seconds, e.g. 90 seconds. As with the first baking step, the second baking step 50 may help to shrink the film, which may reduce the film thickness and further open up the bottom apertures. The wafer is then developed in step 60 , using a solvent to dissolve the exposed areas of photoresist. In step 70 , the wafer is subjected to further, downstream processing through the openings in the photoresist mask, such as plasma etching, deposition, ion implantation, or some other processing step performed through a photoresist mask.
[0033] In other embodiments, the energy density of the radiation in the first exposing can be anywhere from 20% to 80% of that required to convert the photoresist. The remainder of the required energy will then be delivered to the photoresist in the second exposing. In other words, the photoresist is exposed to a first incident energy at approximately 20-80% of that required to create features with a single exposure, and then the photoresist is exposed to a second incident energy that is approximately equal to the difference between the energy used in the first exposing, and that required to create features with a single exposure.
[0034] Using the double exposure/double bake process as outlined in FIG. 2, may lead to the creation of features on the photoresist mask which are substantially smaller than the features in the binary mask used to expose the photoresist film. The reasons for this improvement are the double exposure, wherein the image left by the second exposure is convolved with the image left by the first exposure, along with the double baking steps which reduce the thickness of the photoresist for the second exposure. For instance, features as small as 0.16 μm can be created using a binary mask with binary apertures which are 0.880 μm wide.
[0035] While the characteristic dimensions of the features created in the photoresist mask may be smaller than the aperture size in the binary mask, the characteristic dimensions are also dependent on the radiation dosage and energy density. For a process to be viable in a manufacturing environment, the process needs to have an output which remains within an acceptable range throughout a given input range. The input parameter range reflects the tolerance control of the input parameters. It may be of interest to our readers, therefore, to evaluate the sensitivity of the process results to a range of input parameters, that is, the characteristic dimensions of the contact hole as a function of radiation dosage and energy density. We discuss such testing below.
[0036] To evaluate this sensitivity, the characteristic dimension is measured after varying the incident energy and energy density across an array of points in a test matrix on the surface of a test wafer. The range over which the characteristic feature size is within the desired range, is the process latitude.
[0037] The test array pattern may be written by varying the second exposure dosage for each point on a test wafer. For this series of exposures, features may be created in an array by using different incident energies and different focal spots for each point in the array. The incident energy may be varied by 1.5 mj/cm 2 for each column of features in the array, for example, with the center exposure being 17 mj/cm 2 . The focal spot may be varied by 0.1 μm by moving the stage carrying the wafer up and down by 0.1 μm per row in the array. As a result, a wafer may be created with an array of features (contact holes) of varying size, as a function of incident energy and energy density (focal spot). Therefore, the array may contain information used to determine the process latitude, in terms of acceptable values of incident energy and focal spot, to produce a feature with a given dimension.
[0038] The array features are measured using a VERASEM 3D Scanning Electron Microscope (SEM) manufactured by Applied Materials, Inc. of Santa Clara, Calif. The SEM is used to measure each of the contact holes in the array, in terms of the contact hole diameter. It is also used to evaluate the roundness and cross sectional shape of the contact holes made in the wafer.
EXPERIMENT 1
[0039] A first wafer, test wafer # 1 , was processed according to the flow chart shown in FIG. 2 . The wafer is formed of silicon and provided with a layer of polysilicon to a depth of about 80 nm. A layer of an anti-reflection coating and deep UV photoresist are then provided, as set forth in the above discussion. Because polysilicon has a relatively rough surface topography, the edge definition of features created on the polysilicon surface can be expected to be somewhat less well defined than features created on a smooth surface of, for example, bare silicon. A second test wafer, test wafer # 2 is a bare silicon wafer having the same anti-reflection coating and deep UV resist layer. However, the second wafer is exposed with a single exposure and processed using a single bake following the exposure to provide a comparison with the double exposure/double bake method applied to test wafer # 1 . The test array pattern on test wafer # 2 was created using an exposure energy of 32 mj/cm 2 , with 0.1 μm as the center exposure, and varying the exposure energy by 1.5 mj/cm 2 per column and the focus by 0.1 μm per row in the test array.
[0040] [0040]FIG. 4 a shows the data measured on the polysilicon-coated test wafer # 1 which was subjected to double exposure/double bake process according to FIG. 2. The process latitude is defined as the range of input parameters which results in an acceptable feature size, where the acceptable range is the target range ±10%. Therefore, a process latitude is the range of input parameters which yields a contact hole which is 0.160 μm ± 0 . 016 μm. As can be seen from the data for the test array, the process latitude for creating the 0.16 μm spot size is from −0.1 μm focus (measured contact hole size is 0.152 μm) to 0.3 μm focus (measured contact hole size is 0.149 μm), so that the process latitude for depth of focus is about 0.5 μm. Similarly, the exposure latitude is from about 14 mj/cm 2 to 17 mj/cm 2 , for a ±1.5 mj/cm 2 exposure latitude to create the 0.16 μm spots. The 1.5 mj/cm 2 latitude is equivalent to 8.1% at 0.18 μm contacts (with the center energy at 18.5 mj/cm 2 ), and 8.8% at the 0.17 μm contacts (with the center energy at 17 mj/cm 2 ) and 9.9% at the 0.16 μm contacts (with the center energy at 15.5 mj/cm 2 ). Since a process window of ±10% is standard in the industry, the double exposure/double bake method outlined in FIG. 2 has adequate process latitude, compared with existing industry processes, despite creating features which are substantially (e.g. 60 nm) smaller than those created by the existing industry processes using the same photoresist and lithographic equipment. These results are attributable to the novel process, which uses a double exposure and double bake to widen the process window for creation of the small features.
[0041] In the case of the single exposure/single bake wafer, test wafer # 2 , the data is shown in FIG. 4 b. A 0.3 μm depth of focus process latitude is found for the 0.18 μm contacts, and essentially no depth of focus latitude for the 0.16 μm contacts. Using a center exposure of 32 mj/cm 2 , it can be seen from the data that there is well under 10% exposure latitude for the 0.16, 0.17 and 0.18 μm contacts. Therefore the double exposure/double baked wafer demonstrates a wider process latitude than the single exposure wafer with a single bake.
EXPERIMENT 2
[0042] A third wafer, test wafer # 3 , is a bare silicon wafer with an anti-reflection coating and deep UV resist layers, as discussed above. Test wafer # 3 is processed using a single exposure, but with a double bake, to compare the effects of the different exposure processes with the same baking procedure. The results are similar to those found for the single exposure, single baked wafer, test wafer # 2 , shown in FIG. 4 b. The results for this test wafer # 3 are given in FIG. 5. As can be seen from the data, a 0.4 μm focus process latitude is shown for the 0.18 μm contacts, but there is little process latitude in exposure energy, and little focus latitude for the other target contact dimensions. Therefore, a photoresist process with a second exposure followed by a second baking step results in a wider process latitude, than photoresist process with a single exposure followed by a double bake step.
EXPERIMENT 3
[0043] Finally, two more silicon wafers, test wafers # 4 and # 5 , each coated with an 80 nm layer of polysilicon, an anti-reflection coating and a deep UV photoresist layer, were processed according to the method of FIG. 2, and printed with the test array of points as described above in relation to FIG. 4 a. The center of the process window for the second exposure was 18.5 mj/cm 2 , and 0.1 μm focus for these data, and the target contact hole size was 0.18 μm. The exposure was varied by 0.5 mj/cm 2 per column and 0.1 μm focus per row. The data are shown in FIG. 6, and are presented to show process repeatability and to confirm the findings shown in FIG. 4 a. As can be seen from the data, the process yields repeatable results between the two wafers # 4 and # 5 , to within about 3% at the center of the process windows for the target values, and to within about 10% at the edges of the process windows. The process latitude on depth of focus is about 0.5 μm, and the exposure latitude is again about 1.5 mj/cm .
[0044] The invention is not limited to the exemplary embodiments described above. For instance, the invention is not limited to the particular photoresist materials, deposition techniques or process parameters, layer thicknesses, or other details; the invention is not limited to the particular shapes of the photoresist mask features or their positioning relative to each other; and the invention is not limited to particular materials for the wafer or the layers applied thereon. To the extent that any features of the present invention have been explained or described in relation to beliefs or theories, it should be understood that the invention is not bound to any particular belief or theory. Other embodiments and variations are within the scope of the invention, as defined by the appended claims. | A photoresist exposure process is disclosed which produces features which are substantially smaller than the aperture dimension of the mask used to make the feature. The smaller feature size results from a double exposure of the photoresist, combined with a double baking process to create the features in the photoresist. The double baking process thins the layer of photoresist, prior to the second exposure, thereby improving the resolution of the mark created by the second exposure on the photoresist. The process also uses a binary bias mask through which the first exposure is made, which overlaps with the area of the second exposure, to allow a process tolerance for the realignment of the mask over the wafer for the second exposure. | 6 |
FIELD OF THE INVENTION
This invention relates to locking fasteners and particularly to locking fasteners of the type employing coacting wedge ramps.
BACKGROUND OF THE INVENTION
Locking fasteners are available in which coacting wedge ramps operate to generate wedging forces as the associated nut tends to back off of the associated bolt and these wedging forces are arranged to urge the nut into tighter engagement with the associated bolt and workpiece. These prior art ramp locking wedge fasteners inherently require a higher coefficient of friction between the fastener and the seat engaged by the fastener and between the fastener and the nut than between the contacting wedge surfaces of the fastener. This higher coefficient is usually provided by incorporating radial teeth or serrations on the fastener surfaces where a high friction coefficient is required. If this requirement is not met under all operating conditions, there is no locking action. However, if the teeth do bite into the seat and the nut, the initial loosening of the nut results in movement between the wedge surfaces of the fastener and the tension in the bolt due to initial tightening will actually be increased. These prior art wedge ramp locking fasteners also have the inherent property of requiring a breakaway torque for removing the nut of greater magnitude than the tightening torque used to apply the nut. Whereas locking fasteners operating on these wedge ramp principles work very well in static demonstrations, they have not achieved any widespread commercial acceptance since the nuts associated with the fasteners have tended to back off under the high frequency vibratory loading typically encountered in real life commercial environments.
SUMMARY OF THE INVENTION
This invention is directed to providing an improved locking fastener which is effective to preclude loosening of the associated nut even under high frequency vibratory load conditions.
The invention is further directed to reducing or eliminating the requirements for different coefficients of friction between the various involved surfaces.
The invention basically comprises adding a spring means to the wedge ramp construction and arranging the spring means in such a way that it is compressed or otherwise loaded as the mating wedge surfaces are moved relative to each other as the nut is tightened. Thus a portion of the energy expended to tighten the nut is used to load the spring means.
In broad combination, the invention locking fastener comprises a first portion; a second portion movable relative to the first portion; means operative in response to relative movement between the portions in one direction to decrease the overall axial height of the fastener and operative in response to relative movement between the portions in the opposite direction to increase the overall height of the fastener; and spring means yieldably resisting relative movement of the portions in the one direction and biasing the portions for movement in the opposite direction. With this arrangement, as the portions are moved relative to each other in the tightening operation to decrease the overall axial height of the fastener, the spring means is loaded so that it tends to bias the portions for movement in a direction to expand the overall height of the fastener and thereby augment the locking action of the fastener.
According to a basic feature of the invention, the expansion means comprises coacting, parallel, first and second ramp surfaces on the first and second portions inclined at a greater angle than the thread angle of the associated threaded member. With this arrangement, as the associated nut is threaded onto the associated threaded member, the ramp surfaces move relative to one another in a direction to decrease the overall axial height of the fastener so that loosening movement of the fastener results in attempted expansion of the overall height of the fastener with a resultant resistance to the loosening action.
According to one embodiment of the invention, the fastener comprises a split lockwasher formed of a spring material and having a relaxed configuration in which its opposite ends are spaced; the opposite ends of the lockwasher respectively constitute the first and second fastener portions; and the ramps are configured to undergo relative movement in the direction of decreasing axial height in response to radial contraction of the lockwasher. With this arrangement, as the associated nut is threaded onto the associated threaded member and into locking engagement with the invention lock washer, the ramp surfaces undergo relative sliding movement in a direction to decrease the overall height of the lockwasher against the bias generated by the inherent preload of the lockwasher so that the inherent spring force of the lockwasher tends to attempt to move the ramp surfaces in a direction to expand the axial height of the fastener with a resultant resistance to loosening of the associated nut.
According to a feature of this embodiment of the invention, each of the ramp surfaces extends from the respective end face of the lock washer; a generally axially extending abutment surface extends from the inboard end of each ramp surface to the adjacent upper or lower face of the lockwasher; and each end face is spaced circumferentially from the associated abutment surface in the relaxed configuration of the lockwasher so that as the nut is tightened on the lockwasher, the lockwasher contracts to move the respective end faces into abutment with the respective abutment surfaces.
According to a further feature of this embodiment, the ramp surfaces are spaced axially in the relaxed configuration of the lockwasher so that the lockwasher includes both an axial and a radial preload and both of the preload forces attempt to move the lockwasher in an expanding direction to augment the locking action of the washer.
In another disclosed embodiment of the invention, the fastener comprises a spring washer having a helical configuration with successive convolutions of the helix spaced axially in the relaxed configuration of the washer, and a plurality of pairs of first and second ramp surfaces are provided at circumferentially spaced locations around the convolutions of the lockwasher with each ramp surface pair comprising a first ramp surface on the upper face of a lower convolution and a second ramp surface on the confronting lower surface of an upper convolution. This arrangement has the advantage of distributing the wedging forces around the circumference of the fastener.
According to another embodiment of the invention, the fastener comprises an upper annular member constituting the first portion and a lower annular member constituting the second portion; the first and second ramp surfaces are defined respectively on the upper face of the lower annular member and the confronting lower face of the upper annular member; and the spring means comprises a resilient member positioned between the first ramp surface on the lower member and the second ramp surface on the upper annular member and arranged to be loaded in response to relative movement of the ramp surfaces in a locking direction. This arrangement allows damping forces, which resist vibratory loosening forces, to be easily built in by making the spring of rubber or other rubber-like plastic. This arrangement has the further advantage of balancing the locking axial forces when a loosening torque is applied. A further advantage of this arrangement is that the rubber or rubber-like plastic springs may be used to join the two annular members together while still acting as a spring with a firm bottoming-out point. This arrangement not only provides a convenience in assembly but also serves to hold the two annular members in the proper relative angular position for an accurate and predetermined spring preload.
According to a feature of this embodiment, a plurality of pairs of first and second ramp surfaces are respectively provided at circumferentially spaced locations around the first and second annular members, and a resilient member is positioned between each pair of ramp surfaces and arranged to be loaded in response to relative movement of the associated ramp surfaces in a locking direction. This arrangement provides circumferential distribution of the locking and damping forces while at the same time maximizing the amount of circumferential space available for the damping and locking actions.
In a first form of this embodiment of the invention, the upper and lower annular members comprise upper and lower washers; the upper washer has serrations on its upper face; and the lower washer has serrations on its lower face.
In a further form of this embodiment, the lower annular member comprises a washer and the upper member comprises a nut adapted to be threaded onto the elongated threaded member and into wedging engagement with the underlying washer.
According to a further feature of the invention, a method is provided for securely tightening a nut onto a bolt. The invention method relies on the use of a locking fastener of the type including a first portion defining a first point, a second portion defining a second point and movable relative to the first portion; expansion means operative in response to relative movement between the portions in one direction to decrease the overall axial height of the fastener and operative in response to relative movement between the portions in the opposite direction to increase the overall height; and spring means yieldably resisting relative movement of the portions in the one direction and biasing the portions for movement in the opposite direction. According to the invention tightening method, the locking fastener is positioned on the bolt between the nut and a seating surface; the nut is threadably tightened downwardly on the bolt and downwardly onto the fastener to move the fastener portions in the tightening direction to decrease the overall axial height of the fastener against the yieldable resistance of the spring means; and the nut is thereafter backed off a fraction of a revolution to set the first point on the first portion of the locking fastener into the confronting surface portion of the nut and set the second point on the second portion of the locking fastener into the confronting surface portion of the seating surface. This backing-off action thus sets the locking fastener into both a nut and a washer seat, thereby greatly increasing the effective coefficient or friction between these surfaces and greatly decreasing the chance of the nut backing-off further under vibration; increases the holding power or tension in the bolt; and removes some or all of the twist or torsional deflection in the bolt left over from the original tightening operation.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side view of a first embodiment of the invention locking fastener;
FIG. 2 is a view of the locking fastener of FIG. 1 in use with an associated nut;
FIG. 3 is a view showing the nut and locking fastener of FIG. 2 in a backed-off condition;
FIG. 4 is a side view of a second embodiment of the invention locking fastener;
FIG. 5 is another side view of the locking fastener of FIG. 4 rotated 180° with respect to the view of FIG. 4;
FIG. 6 is a view of the locking fastener of FIG. 4 in use with an associated nut;
FIG. 7 is a side view of a further embodiment of the invention locking fastener with the fastener shown in an unloaded position;
FIG. 8 is a view of the locking fastener of FIG. 7 shown in a loaded position;
FIG. 9 is a top view of the locking fastener of FIGS. 7 and 8;
FIG. 10 is a side view of a further embodiment of the invention locking fastener shown in an unloaded condition;
FIG. 11 is a side view of the locking fastener of FIG. 10 shown in a loaded condition;
FIG. 12 is a top view of the locking fastener of FIGS. 10 and 11;
FIG. 13 is a side view of a further embodiment of the invention locking fastener shown in an unloaded condition;
FIG. 14 is a side view of the locking fastener of FIG. 13 shown in a loaded condition; and
FIG. 15 is a top view of the locking fastener of FIG. 13 showing its disposition in the loaded condition relative to the associated bolt.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The invention locking fastener embodiment seen in FIGS. 1-3 comprises a split lockwasher 10 formed of a suitable spring steel.
Lockwasher 10 includes end portions 10a and 10b formed with coacting ramp surface 10c and 10d and coacting abutment surfaces 10e and 10f. Ramp surfaces 10c and 10d extend inwardly from the respective end face 10g and 10h of the washer at an angle relative to the upper and lower faces 10i and 10j of the washer that is greater than the thread angle of the bolt or other fastener member with which the invention lock washer is to be used. For example, if the lockwasher of Figures 1-3 is intended for use with a threaded fastener having a thread angle of 3 degrees, the circumferential angle θ of ramp surfaces 10c and 10d relative to the upper and lower faces of the lock washer may be 10 degrees. End faces 10g and 10h and abutment surfaces 10e and 10f extend at approximately 90 degrees with respect to the upper and lower faces of the lockwasher.
In its relaxed configuration, as seen in FIG. 1, the invention lockwasher has built in free gaps or clearances in both an axial and a radial direction. Specifically, the ramp surfaces 10c and 10d are separated in the relaxed configuration by a dimension X and the end faces 10g and 10h are separated from the respective abutment surfaces 10e and 10f by a dimension Y. For example, for a lock washer having a nominal inside diameter of 1 inch and a thickness or height of 0.2 inches, the dimension X may be 0.1 inches and the dimension Y may be 0.1 inches.
The invention lock washer is intended for use with a threaded fastener 12 and a hex nut 14 and is designed such that both the axial and radial clearances are reduced to zero with the lockwasher nut and threaded fastener in their assembled or tightened configuration as seen in FIG. 2. Righthand threads are assumed for the fastener 12 and the nut 14 of FIG. 2. As the nut 14 is threaded onto the fastener 12, the lockwasher gradually moves to its bottomed-out condition in Figure 2 in which the end faces 10g and 10h move into abutment with the respective abutment surfaces 10e and 10f and the ramp surfaces 10c and 10d move into sliding, wedging coaction with one another. The various dimensions of the lockwasher are chosen so that the washer bottoms out and behaves as a metal solid washer at some point below the expected full torque of the nut and bolt joint. The lockwasher is further designed such that the combined height or thickness of the overlapped end portions of the washer in the loaded condition of the washer is equal to or slightly greater than the general thickness of the washer.
With the nut and bolt joint tightened to full torque as seen in FIG. 2, the cam surfaces 10c and 10d are fully engaged and the spring loading of the washer is exerting a force in a direction to drive the two ramp surfaces in opposite rotational directions and move them respectively up the associated ramp surfaces and away from the associated abutment surfaces. For such motion to take place, the end portions of the lockwasher must move to a position in which they take up more axial space than in the fully tightened configuration so that, in effect, any such separating movement has the effect of increasing the bolt tension and tightening the joint.
Whereas the fully contracted lockwasher as seen in FIG. 2 provides an effective locking action for the nut and bolt joint, the locking action of the invention lockwasher may be further augmented by backing the nut off by a small amount Z, as seen in FIG. 3, after the nut has been moved to its fully torqued position. This backing off will set the joint by causing the sharp hardened corners 10l and 10m of the lockwasher to respectively dig into the bottom face 14a of the nut and the face of the seating surface 16 against which the lockwasher is being pressed by the tightening action of the bolt. This backing off action provides a visual method of checking whether the washer is working properly since the gap Z can be seen visually and can be measured, and the freshly indented surfaces of the bottom of the nut and the seating surface, mated intimately and interlockingly with the sharp ends 10l and 10m of the washer, virtually guarantee that there will be no loosening rotational motion between the washer and the bottom of the nut or between the washer and the seating surface. The tension loading of the bolt will actually be increased by backing-off the nut a small amount after it has been fully torqued as long as the washer remains stationary relative to the seating surface. The backing-off step also takes out some or all of the residual twist in the bolt normally left in the bolt as a result of the tightening operation. Thus, the backing-off step as performed at assembly has three important advantages. Firstly, it sets the washer teeth into both the nut and the washer seat, thereby greatly increasing the effective coefficient or friction between these surfaces and greatly decreasing the chance of the nut backing-off further under vibration. Secondly, it increases the holding power or tension in the bolt. And thirdly, it takes out some or all of the twist or torsional deflection in the bolt left over from the tightening operation.
The invention locking fastener seen in FIGS. 4, 5 and 6 comprises a spring washer 18 having a helical configuration with the successive convolutions 18a and 18b of the helix spaced axially in the relaxed configuration of the washer. A plurality of pairs of coacting ramp surfaces are provided around the circumference of the convolutions of the lockwasher with each pair comprising a first ramp surface 18c on the upper face of a lower convolution and a second coacting ramp surface 18d on the confronting lower face of an upper convolution. As with the single convolution lockwasher of the FIG. 1-3 embodiment, ramps 18c and 18d are inclined at a greater effective angle than the thread angle of the threaded fastener with which the lockwasher is to be used. Lockwasher 18 further includes end faces 18e and 18f, and an abutment surface 18g associated with each ramp surface. In the relaxed configuration of the lockwasher of FIGS. 4, 5 and 6 associated coacting ramp surfaces 18c and 18d are separated by an axial distance X and the associated abutment surfaces 18g are separated by a circumferential dimension Y. For example, for a spiral lockwasher having a nominal inside diameter of 1 inch and an effective thickness of 0.2 inches, the axial unloaded clearance dimension X may be 0.2 inches and the circumferential unloaded clearance dimension Y may be 0.1 inches.
As the nut 14 is tightened downwardly onto the threaded fastener 12, the axial and circumferential preloads of the lockwasher are taken up and the ramp surfaces 18c and 18d move into wedging sliding coaction and the abutment surfaces 18g move into abutting relation to define the totally compressed condition of the lockwasher as seen in FIG. 6. As with the embodiment of FIGS. 1-3, the lockwasher moves into its totally compressed or bottomed-out condition well before the expected full torque of the nut and bolt joint is reached. Serrations 18h on the lower face of lower convolution 18a facilitate locking engagement of the washer with the seating surface 16 and serrations 18i on the upper face of upper convolution 18b facilitate locking engagement of the lockwasher with the lower face of nut 14. As seen in FIG. 5, lower and upper convolutions 18a and 18b may lie in vertically spaced, parallel, horizontal planes with the lower and upper convolutions joined by an upwardly cranked bridge portion 18j which is the devoid of ramp surfaces 18c, 18d.
The locking fastener of the FIGS. 7-9 embodiment comprises an upper annular lockwasher 20, a lower annular lock washer 22, and a plurality of spring members 24.
Lockwashers 20 and 22 may be identical. Ramp surfaces 20a and 22a are provided respectively on the lower annular face of upper washer 20 and the upper annular face of lower washer 22. For example, three such pairs of ramp surfaces may be provided around the circumference of the lockwashers. Each ramp surface includes a coacting abutment surface 20b or 22b.
Spring members 24 comprise rubber elements which are interposed between each pair of coacting ramp surfaces 20a and 22a and which are moved into compression in response to relative rotational movement between the upper and lower washers occurring in response to tightening of the nut onto the fastener member and into rotational engagement with the upper face of the upper washer. Rubber members 24 are desirably suitably secured to the upper and lower washers so as to hold the upper and lower washers in an assembled relation and so as to relatively position the upper and lower washers for assembly purposes and ensure proper sliding coaction between the coacting ramp surfaces when the nut is tightened downwardly onto the lock washers.
Specifically, the rubber members can be bonded to the two lock washers in a manner to determine their relative circumferential and axial positions in their free or unloaded position, thereby determining the amount of the spring load and the amount of the breakaway torque that will finally cause the washer to break away and and thereby permit the nut to loosen on the bolt. For example, the opposite ends of each rubber segment 24 may be respectively secured to the two successive abutment surfaces 20b and 22b and the unloaded segment may occupy approximately half of the volume bounded by surfaces 20a, 22a, 20b, and 22b. As the nut is tightened downwardly onto the upper lock washer, and as best seen in FIG. 8, the ramp surfaces slide downwardly and wedgingly relative to one another and the rubber spring members are compressed to totally fill the decreased volume bounded surfaces 20a, 22a, 20b, and 22b. In this position, the rubber segments are loaded and act as springs urging the lockwashers to undergo relative rotation to move the ramp surfaces 20a up the associated ramp surfaces 22a and increase the effective thickness of the lockwasher assembly and thereby increase the bolt tension and tighten the joint.
As with the FIGS. 1-3 embodiment, the locking action of the lockwasher assembly may be augmented by backing the nut off a small amount after the nut has been brought up to full torgue so as to set the serrations 20c and 22c on the upper and lower faces respectively of the upper and lower lockwashers into the surface of the adjacent seating surface and into the surface of the adjacent nut so that no further motion in a loosening direction can take place.
For example, a typically highly loaded 3/8 inch bolted joint may have a 40 foot pound torque specification which normally produces between 3000 and 4000 pounds of tension in the bolt. With a correctly designed lockwasher of the type seen in FIGS. 7-9, the nut could be tightened to 35 foot pounds and than backed off approximately 10 degrees. Depending on the length of the bolt and other factors, the tension in the bolt would then actually be increased toward what it would have been with the 40 foot pound torque specification. At the same time, the backing off action sets the teeth of the serrations 20c and 22c into the surface of the nut and the surface of the seat respectively so that no further motion in a loosening direction can take place. In addition, this reverse torque operation or backing off after full torquing takes out some of the twist or torsional deflection remaining in the bolt as the result of the tightening operation. This relieves some of the fundamental residual forces normally left in torque joints after the tightening that can operate over periods of time to cause loosening of the joint under vibratory loads. In order for this setting or backing off action to occur, the stored spring force energy driving the washers in opposite directions must be sufficient to overcome the difference between the friction torque between the seating surface and the washer and the friction torque between the ramp surfaces plus the wedge angle which may be, for example, in the order of 10 degrees. As the digging in process starts, the stored spring force energy begins to be dissipated by the relative movement up the wedges which forces the setting action desired. The amount of preload necessary to accomplish the digging in for optimum locking will of course vary for different joints.
The locking fastener seen in FIGS. 10-12 is similar to the locking fastener seen in FIGS. 7-9 in the sense that the fastener comprises upper and lower annular members and spring members interposed between coacting ramp surfaces defined on the upper and lower members. However, in the FIG. 10-12 embodiment, the upper annular member comprises a hexagonal nut 26 for threaded coaction with the fastener member 12 and the lower annular member comprises a hexagonal washer 28 having a larger outside hexagonal shape than the nut. Coacting ramp surfaces 26a and 28a are provided on the nut and on the washer and abutment surfaces 26b and 28b are provided in association with each ramp surface. A rubber spring element 29 is interposed between each pair of coacting ramp surfaces. Spring elements 29 are secured at their opposite ends to successive abutment surfaces 28b and 26b so that the rubber springs are compressed to fill the entire space between the confronting ramp surfaces as the locking fastener is moved to its locking or loaded position as seen in FIG. 11.
A special torque wrench (not shown), with both the nut and washer hex sizes in it, could be used to tighten and loosen the locking fastener of FIGS. 10-12 so as to control the relative rotation for the locking action and the setting action to achieve precise and controllable initial locking and precise and controllable backing off or setting action. The smaller hex fitting the nut would be used to tighten the nut with the larger hex free wheeling so that it drags behind the inside or smaller hex as the spring elements between the nut and the washer are compressed during tightening. When the desired torque is reached for the bolt load desired, the angle between the smaller hex and the larger hex would indicate the amount of preload put into the springs. Furthermore, to ensure setting, the larger hex wrench on the washer could then be held stationary while the smaller hex on the nut could be backed-off a preset angle before beginning to free wheel so that a good set could be assured.
For those designs incorporating rubber or rubber-like spring elements between the upper and lower members (FIGS. 7-9 and 10-12) it may be desirable to eliminate one or more of the spring elements and to shorten the length of the ramps where the eliminated spring element would have been installed so that metal-to-metal contact occurs between the two members after the full spring load has been applied during the tightening process. Experience has shown that rubber and rubber-like materials may not be able to take the full tightening force in compression and may be extruded out of the space between the locking members. One or more metal-to-metal stops arranged to contact at the desired pre-load deflection of the rubber would prevent this.
The locking fastener 30 of FIGS. 13-15 is similar to the locking fastener 10 of FIGS. 1-3 with the exception that the lock washer is arranged to expand radially in response to tightening of the associated nut. Specifically, as the associated nut is tightened, ramp surface 30a on end 30b slides downwardly along ramp surface 30c on end 30d and ramp surface 30e on end 30d slides downwardly along ramp surface 30f on end 30b to decrease the axial thickness of the washer but increase the radial dimension of the washer. Thus, as seen in FIG. 15, as the associated nut is tightened, the washer expands and is deflected outwardly away from the bolt to preclude interference between the washer and the bolt which, in some applications, can interfere with the tightening action of the locking fastener assembly.
The invention locking fasteners will be seen to provide an improved locking fastener in which the spring elements act constantly to drive the opposed wedge surfaces in opposite rotational directions to increase the locking action so that the spring elements and the wedge surfaces coact on a continuing basis to preclude loosening of the joint.
Whereas preferred embodiments of the invention have been illustrated and described in detail, it will be apparent that various changes may be made in the diclosed embodiments without departing from the scope or spirit of the invention. | A locking fastener in which coacting ramp surfaces are employed to generate wedging forces in response to backing-off movement of the associated nut which urges the nut into tighter engagement with the associated bolt and workpiece and in which spring means are provided which are compressed during the tightening operation and which bias the ramp surfaces for movement in a direction to augment the locking action of the fastener. | 5 |
This application claims benefit of Provisional Application No. 60/045,815 filed May 7, 1997.
FIELD OF THE INVENTION
This application relates to libraries of compounds based upon N-(4-alkoxyphenyl)-N-acyl-benzylamine, N-(4-alkoxyphenylmethyl)-N-acyl-benzylamine and N-[2-(4-alkoxyphenyl)ethyl]-N-acyl-benzylamine templates, to processes for the preparation of such libraries and their use as a screening tool in biological assays for identifying new chemical leads.
BACKGROUND OF THE INVENTION
In the past, new leads for drug discovery have been generated by random cross screening of single synthetic compounds made individually in the laboratory or by screening extracts obtained from natural product sources such as microbial metabolites, marine sponges and plants. A second approach has been rational drug design based on the structure of known biologically active compounds and/or their sites of biological action. This has now been complemented by the powerful techniques of computer-assisted drug design.
There has recently been an explosion in the availability of new screening targets arising from the output of efforts to sequence the human genome and bacterial genomes. This has led to the development of high throughput screening techniques. Groups of compounds, typically eight, are exposed to a biological target. These groups may be assembled from collections of compounds previously individually prepared and since stored in a compound bank, the assembly being random or guided by the use of "similarity" programs. In addition, there has also been a rapid growth in the deliberate preparation and use of so-called libraries and/or arrays of compounds. Each library contains a large number of compounds which are screened against a biological target such as an enzyme or a receptor. When a biological "hit" is found, the compound responsible for the "hit" is identified. Such compound, or lead, generally exhibits relatively weak activity in the screen but forms the basis for the conduct of a more traditional medicinal chemistry program to enhance activity. The libraries may be prepared using the rapidly developing techniques of combinatorial chemistry or by parallel synthesis (DeWitt et al, Proc Natl Acad Sci, 90, 6909, August 1993; Jung et al, Angew Chem Int Ed Engl, 31:367-83, 1992; Pavia et al., Bioorg Med Chem Lett, 3:387-96, 1993).
The first libraries were composed of small polypeptides, with some libraries containing up to 10,000 members. Such libraries could be made by adapting the techniques developed for the synthesis of single polypeptides (see, for instance, Lam et al, Nature, 354: 82, 1991 and WO 92/00091; Geysen et al, J Immunol Meth, 102: 259, 1987: Houghten et al, Nature, 354: 84, 1991 and WO 92/09300 and Lebl et al, Int J Pept Prot Res, 41, 201, 1993). The chemistry involved, forming an amide bond, is relatively straightforward and automated peptide synthesisers can be employed to reduce the manual effort involved. However, small polypeptides do not provide ideal leads for drug discovery. Peptides are not generally useful as therapeutic agents and there exists no rational way of translating a peptide into a therapeutically useful small molecule (peptidomimetic). A similar approach has also been used with nucleotides, taking advantage of the progress made in automated nucleotide synthesis, and with oligomers.
Attention has therefore turned to preparing libraries of small non-peptide molecules based upon a common template or core structure [see for instance Ellman and Bunin, J Amer Chem Soc, 114:10997, 1992 (benzodiazepine template), WO 95/32184 (oxazolone and aminidine template), WO 95/30642 (dihydrobenzopyran template) and WO 95/35278 (pyrrolidine template)]. The template will have a number of functional sites, for instance three, each of which can be reacted, in a step-wise fashion, with a number of different reagents, for instance five, to introduce 5×5×5 different combinations of substituents, giving a library containing 125 components. The library will normally contain all or substantially all possible permutations of the substituents. The template may be a so-called `biased` template, for instance incorporating a known pharmacophore such as a benzodiazepine ring or a so-called `unbiased` template, the choice of which is influenced more by chemical than biological considerations. Unbiased templates are considered to offer the greater potential for generating entirely new leads.
The real challenge in creating a small molecule library which is useful as a screening tool is to provide a diverse range of substituents comprising a wide range and variety of structural units which allow the library as a whole to explore as fully as possible the active site of a receptor or an enzyme in an assay by having the potential for a wide range of interactions such as hydrogen bonds, salt bridges, π-complexation, hydrophobic effects etc. The actual substituents are selected by considering their physico-chemical properties such as, for example, electronic, ionic, lipophilic and steric properties in order that the library contains maximum structural diversity. For example, if a core structure is to have a C 1-6 alkyl substituent at a particular position, a typical library may have component compounds in which that substituent is methyl and t-butyl. An adamantyl group provides a good example of a large, bulky hydrophobic group. Substituents on an aromatic ring may be varied according to well established principles of medicinal chemistry, e.g., as reflected in the Topliss and Craig diagrams. Suitable diverse heteroaryl groups may be chosen according to well-known medicinal chemistry principles. For instance, a pyridinyl group may be selected if a basic group is desired. In addition, computer programs have now been developed to assist in this process, for instance SYBYL molecular diversity manager (Tripos Inc, Mo, USA). It is also useful to avoid mass redundancies when selecting suitable substituents, to aid identification of different library members by mass spectroscopy. Tables have been devised to assist in this task (PCT/EP96/03731, SmithKline Beecham).
For maximum synthetic efficiency in creating a library, the introduction of different substituents at each functional site should be accomplished as a single step, using a mixture of reagents, one for each different substituent. A diverse range of substituents can however translate into a diverse range of reactivities for the reagents. It is often more convenient to adopt the so-called `split and mix` approach whereby the evolving library is split into a series of parallel aliquots, each containing the same mixture. Each aliquot is then reacted with a single but different reagent, to introduce a further variant, and the new sub-libraries can then be recombined before splitting again, for a further synthetic cycle (Furka et al, 14th Intl Congress of Biochemistry, Prague, July 1988; Furka et al, Int J Peptide Protein Res, 37: 487, 1991). Such an approach is of assistance in coping with different reactivities of diverse reagents and also in deconvoluting a library, once a hit is found. The progress of reactions may be monitored using various techniques, for instance the disappearance of a functional group such as an amine. Single bead mass spectroscopy allows the possibility of selectively sampling and analyzing large numbers of compounds, enabling this technique to be used to monitor and/or analyze libraries. Solid phase NMR, in particular so-called `magic angle` NMR, can also be usefully applied.
A complementary approach to creating a library of compounds is to use the parallel synthesis method, whereby the compounds comprising the library are prepared separately and in parallel. Usually, the various reaction steps are not monitored and little or no effort is made to purify or isolate intermediate compounds (DeWitt et al, Proc Nat Acad Sci USA, 90:6909-13, 1993). The chemistry may be carried out in the solution phase or using solid phase supports. This allows for a greater rate of synthesis, although at the possible expense of incomplete reactions. Compounds may be screened individually or they may be grouped together, for instance if there is a limited supply of screening target. Either way, deconvolution, once a "hit" is found, is then assisted by the existence of individual compounds. This approach is becoming increasingly automated and is attractive for the preparation of a small number of compounds. For larger libraries, the combinatorial approach becomes increasingly more efficient, as far fewer reactions have to be carried out.
The screens in which the libraries are assayed tend to be based on enzymes or receptors. These are becoming increasingly automated, giving them a high throughput and making the use of libraries more attractive. Furthermore, once created, libraries can become a screening resource which can be used many times over, both for existing screens and, held in reserve, for new screens as they are developed.
SUMMARY OF THE INVENTION
An object of the present invention is to provide a library of compounds based on N-(4-alkoxyphenyl)-N-acyl-benzylamine, N-(4-alkoxyphenylmethyl)-N-acyl-benzylamine and N-[2-(4-alkoxyphenyl)ethyl]-N-acyl-benzylamine templates and sub-libraries thereof. A further object of the present invention is to provide processes for the preparation of such libraries. Yet another object of the present invention is to provide processes for the use of such libraries as screening tools in biological assays for identifying new chemical leads.
DETAILED DESCRIPTION OF THE INVENTION
The present invention provides for a library comprising 1,200 different compounds of Formula I: ##STR1## wherein: R 1 is ethyl, methyl or a single bond;
R 2 is malonyl, succinyl, glutaryl, B-alanyl, 4-aminobutyryl, 5-aminovaleryl, 6-aminocaproyl, 3-(4-hydroxyphenyl)propionyl, 3-methoxypropionyl, acetyl, trans-cinnamyl, hydrocinnamyl, 4-nitrobenzoyl, 2-naphthalenecarbonyl, isovaleryl, 4-chlorobenzoyl, phenylacetyl, 4-biphenylcarbonyl, methoxyacetyl or glycyl;
R 3 is 2-dimethylaminoethyl, 3-dimethylaminopropyl, 4-pyridinylmethyl, 3-pyridinylmethyl, 6-dimethylaminohexyl, 2-(methylphenylamino)ethyl, 2-(benzylmethylamino)ethyl, 2-pyridinylmethyl, 3-(4-pyridinyl)propyl, 4-dimethylaminophenethyl, hydro, 5-diethylaminopentyl, (S)-1-(4-nitrophenyl)-2-pyrrolidinomethyl, 2-(N,N-dibenzylamino)ethyl, 2-{[2-(dimethylamino)ethyl]methylamino)}ethyl, 1, 3-bis(dimethylamino)-2-propyl, 2-(2-pridinyl)ethyl, benzyl, ethyl, or 2-methoxyethyl.
Such a library is useful in screening for new chemical leads for drug discovery.
Suitably, the library is a combinatorial library, that is, a library prepared using a combinatorial chemistry approach.
The term "library" as used hereinafter refers to a collection of individual compounds which have a common core structure or template which has a discrete number of independently variable substituents, each of which can have one of a defined range of values. Preferably, the library is designed so that, for the range of values selected for each of the independently variable substituents, compounds containing all possible permutations of these substituents will be present in the library. Thus, if a template contains three independently variable substituents, X, Y and Z, and if X is one of m different chemical moieties, Y is one of n different chemical moieties and Z is one of p different chemical moieties (in which m, n and p are integers which define the size of the library, and which range between 1 to 1000; preferably between 1 to 100; more preferably between 1 to 20), then the library would contain m×n×p different chemical compounds and all possible combinations of X, Y and Z would be present on the template within the library. This may be regarded as an "ideal" or complete library. The term "library" is also used to refer to a collection of compounds in which substantially all of the members of the `ideal` or complete set of compounds are present, for instance at least 80%, preferably 90%, more preferably 95%. It will be appreciated that, in some instances, a certain number of the individual compound members of a library might not synthesized, for instance a particular intermediate may show low reactivity towards a specific reagent as a consequence of steric hindrance or electronic factors. In addition, a statistical analysis of a library prepared using the "split and mix" technique shows that not all the compounds theoretically preparable will in reality be prepared. A library may be composed of a series of sub-libraries, each having the same common core and, for instance, all permutations of X and Y and each sub-library having only one value of Y. For the purposes of screening, it may be more convenient to keep the sub-libraries separate, rather than combine them.
A typical library will contain between 2 to 10,000 or more compounds, preferably 10 to 1,000 compounds, and more preferably 10 to 500 compounds. A typical sub-library may comprise up to 200 members.
Such libraries are suitably prepared by the methods of combinatorial chemistry or by parallel synthesis.
It will be readily appreciated that smaller sub-libraries of the main libraries may also be prepared and these are of use in deconvoluting a main library. Compounds of a library may be bound to a solid phase support such as a resin, used to facilitate the synthesis thereof, and this is generally referred to as a `solid phase` library, in particular a `resin-bound`-library. Compounds of a library which have been cleaved from a solid phase support are generally referred to as a `soluble` library. The present invention encompasses all such libraries and sub-libraries. Suitable sub-libraries include those given in which either R 1 or R 2 have the full range of values while the other R group has a single, fixed value.
Compounds for inclusion in libraries according to the present invention may be made by the combinatorial approach. Alternatively, such compounds may be made individually, either by a conventional synthesis or by the parallel synthesis approach, using manual or automated techniques.
The compounds of Formula I are prepared by solid phase organic synthesis. Suitable solid phase supports include resins which are well known in the art and include includes beads, pellets, disks, capillaries, hollow fibers, needles, solid fibers, cellulose beads, pore-glass beads, silica gels, polystyrene beads optionally cross-linked with divinylbenzene, grafted co-poly beads, poly-acrylamide beads, latex beads, dimethylacrylamide beads optionally cross-linked with N,N-bis-acryloyl ethylene diamine, POLY-HIPE™, TENTAGEL™, etc. Both smaller (for instance about 30 to 80 μm) and larger beads (for instance about 200 to 300 μm) are available from commercial suppliers, the latter being preferred for single bead screening.
The template is synthesized from a 4-(hydroxymethyl)phenyl-2-dimethylsilyl)propionamidomethylphenyl resin. The hydroxymethylphenyl group is first transformed to a resin bound benzylbromide and alkylated with either tyramine, 4-hydroxybenzylamine or 4-aminophenol. The secondary amine which is formed is next acylated with various acids derived from R2 via the acid chloride or coupled using standard coupling methods. Any acylated phenol is then hydrolyzed by treatment with base then coupled with a variety of alcohols derived from R3, via the Mitsunobu reaction. The final product of Formula I is released from the resin by treatment with trifluoroacetic acid or any method known to cleave aryl silicon bonds. A representative synthesis is given in Scheme 1 below. As used herein in Scheme 1, the term "polymer" is a polystyrene polymer.
It will be appreciated that reactive functional groups in the alkyl and acyl substituents R 2 and R 3 may require temporary protecting groups during the synthesis. Ideally, these protecting groups are either selectively removable before cleavage from the resin or are removed concomittantly with cleavage of the compound from the resin. For example, primary and secondary amino groups can be protected as their t-Boc derivatives, alcohols or phenols as their t-butyl ether derivatives and carboxylic acids as their t-butyl ester derivatives. ##STR2##
In the following synthetic examples, temperature is in degrees Celsius (° C.). Unless otherwise indicated, all of the starting materials were obtained from commecial sources. Without further elaboration, it is believed that one skilled in the art can, using the description provided in this specification, utilize the present invention to its fullest extent. These examples are given to illustrate the invention, not to limit its scope. Reference is made to the claims for what is reserved to the inventors hereunder.
EXAMPLE 1
Preparation of Aminomethyl Polystyrene 1% DVB. (1-Scheme 1)
To chloromethylated polystyrene 1% DVB (25 g, Polymer Labs, 2.0 mmol/g, avg. dia. 290 u) in a silanized 500 mL round bottom flasked were added potassium di-t-butyl iminodicarboxylate (25 g, 80 mmol) and dry DMF (200 mL). The reaction mixture was purged with argon and stirred by rotation, under argon, on a rotovap at 60° C. for 24 h. The reaction was then cooled, filtered and washed successively with DMF (x2), (1:1) DMF, H 2 O (x2), methanol (x2), air dried for 16 h then dried under vacuum for 24 h. Analysis % N 1.96 (95% of theoretical); MAS-NMR (500 mHz, CDCl 3 ) disappearance of the peaks at d 4.38 and 4.50 ppm (chloromethyl polystyrene) and formation of a new methylene peak at d 4.62 ppm and a t-butyl peak at d 1.38 ppm.
The above resin was treated with a solution of 90% trifluoroacetic acid in CH 2 Cl 2 (200 mL) for 1 h at room temperature, filtered, washed with CH 2 Cl 2 (x2), neutralized with a solution of 10% diisopropylethylamine (DIEA) in CH 2 Cl 2 (200 mL) for 15 min., washed with CH 2 Cl 2 (x2), then methanol (x4). The resin was air-dried for 16 h then dried under vacuum for 24 h. (23.45 g) Analysis % N 3.01, calculated substitution 2.15 mmol/g; MAS-NMR (500 mHz, CDCl 3 ) d 3.76 and 3.63 ppm.
EXAMPLE 2
Preparation of 3-[4-(Hydoxymethyl)Phenyldimethylsilyl]Propionamidomethyl Polystyrene 1% DVB. (2-Scheme 1)
3-[4-(hydroxymethyl)phenyldimethylsilyl]propionic acid (14.9 g, 63 mmol) (reference patent or manuscript in preparation), 1 -hydroxybenzotriazole (HOBt) (16.9 g, 125 mmol) and dicyclohexylcarbodiimide (DCC) (14.4 g, 70 mmol) were added to a slurry of aminomethylated polystyrene 1% DVB (25.0 g, 2.15 mmol/g, 53 mmol) and DMF (200 mL). The slurry was shaken for 16 h, filtered, washed with DMF (x2), (1:1) CHCl 3 , MeOH (x2), CH 2 Cl 2 (x2), MeOH (x4) and dried under vacuum for 24 h. A Kaiser test (E. Kaiser, R. L. Colescott, C. D. Bossinger and P. I. Cook, Anal. Biochem. 34, 595-598, 1970) of the resulting resin was negative. Analysis % N 1.18, calculated substitution 1.30 mmol/g; MAS-NMR (500 mHz, CDCl 3 ) d (7.44, 2H), (7.29, 2H), (4.56, 2H), (4.20, 2H), (2.06, 2H), (1.06, 2H), (0.26, 6H).
EXAMPLE 3
Preparation of 3- [4-(Bromomethyl)Phenyldimethylsilyl]Propionamidomethvl Polystyrene 1% DVB. (3-Scheme 1)
To a suspension of resin 2-Scheme 1 (6.0 g, 7.8 mmol) in dry THF (80 mL) in a shaker vessel were added CBr 4 (5.4 g, 16.3 mmol) followed by triphenylphosphine (4.3 g, 16.4 mmol). The reaction was shaken for 24 h. (A thick white precipatate formed.) The resin was washed with THF (x3), EtOH (x2), CH 2 Cl 2 (x2) then dried under vacuum for 24 h. (7.7 g) Analysis % N 1.41, % Br 8.36, calculated substitution 1.05 mmol/g; MAS-NMR (500 mHz, CDCl 3 ) disappearance of the peak at d 4.56 and formation of a new methylene peak at d 4.24 ppm.
EXAMPLE 4
General Preparation of Phenolic-Amines. (4-Scheme 1)
To a Suspension of resin 3-Scheme 1 (7.7 g, 7.8 mmol) in dry DMF (60 mL), in a shaker vessel were added the phenol-amine derived from R1 (ie. tyramine, 4-hydroxybenzylamine or 4-aminophenol) (78 mmol, 10 mol equiv.) and triethylamine (11 mL, 78 mmol). The reaction was shaken for 24 h, filtered and washed with DMF (x2), MeOH (x2), (1:1) CHCl 3 , MeOH (x2), MeOH (x2) then dried under vacuum.
EXAMPLE 5
General Proceedure for the Acylation of the Phenolic-Amines. (5-Scheme 1)
via the acid anhydride;
To a suspension of resin 4-Scheme 1 (300 mg, 0.36 mmol) in CH 2 Cl 2 (8 mL) in a shaker vessel were added pyridine (122 uL, 1.5 mmol) followed by the acid anhydride derived from R2 (1.1 mmol, 3 equiv.). The reaction was shaken for 16 h, washed with CH 2 Cl 2 (x2) and methanol (x2).
via the carboxylic acid;
To a suspension of resin 4-Scheme 1 (300 mg, 0.36 mmol) in DMF (8 mL) in a shaker vessel were added diisopropylethylamine (192 uL, 1.1 mmol), pyridine (178 uL, 2.2 mmol), the carboxylic acid derived from R2 (1.1 mmol, 3 equiv.) and bis-pentamethylene-fluoro-foramidinium-hexafluorophosphate (379 mg, 1.1 mmol) (Carpino et al, JACS 1995 117 5401-5402). The reaction was shaken for 16 h, washed with DMF (x2), CH 2 Cl 2 (x2) and methanol (x2).
via the acid chloride;
To a suspension of resin 4-Scheme 1 (300 mg, ˜0.36 mmol) in CH 2 Cl 2 (8 mL) in a shaker vessel were added diisopropylethylamine (260 uL, 1.5 mmol) followed by the acid chloride derived from R2 (1.0 mmol, 3 equiv.). The reaction was shaken for 16 h, washed with DMF (x2), CH 2 Cl 2 (x2) and methanol (x2). All of the above reactions after coupling were saponified with a solution of (1:1) aq. 1N NaOH, DMF (8 mL) with shaking at room temperature for 16 h then washed with (1:1) DMF, H 2 O (x2), a solution of HOAc (100 uL, 1.8 mmol) in (1:1) DMF, H 2 O, (1:1) DMF, H 2 O (x2), DMF (x2), methanol (x2) and THF (x2).
EXAMPLE 6
General Proceedure for Doing the Mitsunobu Reaction. Resin 6-Scheme 1
To a suspension of resin 5-Scheme 1 (300 mg, ˜0.36 mmol) in dry THF (8 mL) under an atmosphere of Ar were added the alcohol derived from R3 (1.8 mmol, 5 equiv.), triphenylphosphine (0.48 g, 1.8 mmol), followed by diisopropyl azodicarboxylate (DIAD) (0.36 mL, 1.8 mmol). The reaction was shaken for 4 h then washed with THF (x2). The reaction was repeated four times then thoroughly washed with THF (x2), methanol (x2), CH 2 Cl 2 (x2), hexane and dried under vacuum.
EXAMPLE 7
General Proceedure for Doing the TFA Vapor Cleavage Reaction. Compound 7-Scheme 1
Resin 6-Scheme 1 (From a single bead to a bulk sample) was exposed to TFA vapor (by placing the resin in a filter funnel or open vial, within a closed container containing a layer of TFA on the bottom) at room temperature for 72 h. The resin after drying under vacuum and extraction with methanol, filtration and evaporation gives compound 7-Scheme 1.
The "split and mix" technique referred to previously may conveniently be used to more efficiently conduct the synthesis of the final library and also to provide intermediate sub-libraries to assist the deconvolution of a library, once a "hit" has been made in a biological assay. It will be understood that by using this approach, each bead will have bound to it a unique compound member of the library.
Accordingly, in a further aspect, the present invention provides a method for synthesizing a combinatorial library of different compounds, comprising the steps of:
(a) attaching a compound of Formula II: ##STR3## to resin beads selected from the group consisting of benzhydrylamino or aminomethylated polystyrene;
(b) transformation the above resin to the corresponding resin bound benzylbromide.
(c) splitting the resin beads into 3 first aliquots;
(d) reacting each of said first 3 aliquots with a different phenol-amine selected from a group of consisting of tyramine, 4-hydroxybenzylamine and 4-aminophenol;
(e) mixing together the 3 different first reaction products to form a mixture;
(f) splitting said first mixture into 20 second aliquots;
(g) coupling each of said 20 second aliquots with a different carboxylic acid selected from a group of carboxylic acids consisting of malonic acid mono-t-butyl ester, succinic acid mono-t-butyl ester, glutaric acid mon-t-butyl ester, N-Boc-B-alanine, N-Boc-4-aminobutyric acid, N-Boc-5-aminovaleric acid, N-Boc-6-aminocaproic acid, 3-(4-t-butoxyphenyl)propionic acid, 3-methoxypropionic acid, acetic acid, trans-cinnamic acid, hydrocinnamic acid, 4-nitrobenzoic acid, 2-naphthalenecarboxylic acid, isovaleric acid, 4-chlorobenzoic acid, phenylacetic acid, 4-biphenylcarboxylic acid, methoxyacetic acid or N-Boc-glycine to provide 20 second reaction products;
(h) mixing together the 20 different second reaction products to form a mixture;
(i) saponifying any acylated phenolic esters.
(j) splitting said second mixture into 20 third aliquots;
(k) coupling each of said 20 third aliquots by the Mitsunobu reaction with a different alcohols selected from a group of alcohols consisting of 2-dimethylaminoethanol, 3-dimethylaminopropanol, 4-pyridinylmethanol, 3-pyridinylmethanol, 6-dimethylaminohexanol, 2-(methylphenylamino)ethanol, 2-(benzylmethylamino)ethanol, 2-pyridinylmethanol, 3-(4-pyridinyl)propanol, 4-dimethylaminophenethyl alcohol, 5-diethylaminopentanol, (S)-1-(4-nitrophenyl)-2-pyrrolidinomethanol, 2-(N,N-dibenzylamino)ethanol, 2-{[2-(dimethylamino) ethyl]methylamino}ethanol, 1,3-bis(dimethylamino)-2-propanol, 2-(2-pridinyl)ethanol, benzyl alcohol, ethanol, or 2-methoxyethanol to provide 20 third reaction products;
(l) optionally, and if so desired, cleaving at least a portion of the third reaction products with trifluoroacetic acid or any known reagent that cleaves aryl-silyl bonds to provide the library in soluble form.
It will be understood that for an aliquot when R 3 is hydrogen, step (k) of the process will not be performed.
Formula II may be prepared by the process described in U.S. provisional application No. 60/017955 filed May 20, 1996.
Libraries in which the members thereof are bound to a solid phase support are particularly useful as intermediates in the preparation of final libraries. Accordingly, in a further aspect, the present invention provides for a library comprising up to 60 different compounds of Formula III: ##STR4## in which R 3 is as hereinbefore defined.
Single beads having a single compound may be prepared by parallel synthesis or the split and mix techniques hereinbefore described. In a further aspect, the present invention provides for a resin bead having a single compound of Formula I. Such beads are preferred for screening purposes. Useful libraries of the present invention are those consisting of resin beads in which each resin bead has a single compound of Formula I.
Libraries of the present invention are useful as screening tools, for the identification of compounds with biological activity. Accordingly, in a further aspect, the present invention provides for the use of a library as hereinbefore defined in identifying compounds with biological activity.
Conventionally, libraries have been screened as solutions in aqueous dimethyl sulphoxide. Polymer bound libraries are first cleaved to create soluble libraries. Small (microlitre) volumes can then be reproducibly and accurately measured out for use in each assay, as needed. The solutions can be stored frozen at low temperature (-20° C.), to prolong the useful life thereof.
After a "hit" is found in a soluble library, the library is deconvoluted to identify the member(s) thereof responsible for the "hit", according to principles well-known to those skilled in the art, for instance using an iterative or a scanning approach.
Using an iterative approach, sub-libraries of decreasing complexity are screened individually, to narrow down the field of search. These may have been created during the original synthesis of the library, with a portion being set aside. Alternatively, a first sub-library may be prepared by repeating all but the final step of the preparation of the library, so that this sub-library contains all the possible variations in substituents at all but one position. This sub-library is then split into a series of aliquots, one for each variation in the remaining substituent. Each aliquot is then treated with a different reagent which will introduce each of the variations of the final substituent, individually. This will create a series of parallel sub-libraries, each of which will have a single value for the final substituent. These can then be screened, to identify which of the values of the final substituent is responsible for the `hit`. The iteration may then be continued for the other substituents, starting with a sub-library containing all but the final two substituents. This sub-library is then divided into a series of aliquots for introducing individually each of the values of the penultimate substituent. Each of the aliquots is then reacted with a reagent to introduce the value of the ultimate substituent which was found to give a `hit`, thereby creating a series of parallel sub-libraries. These can then be screened to identify which combination(s) of the ultimate and penultimate substituents give a `hit`. Ultimately, it will become necessary to prepare the individual members of a sub-library, to identify the specific compound. The parallel synthesis approach may be of use in this process. If a template has three variables X, Y and Z, each of which can have a, b and c values, to give a library with a×b×c members, it can be deconvoluted by the iterative approach with a+b+c syntheses.
Using the scanning approach, a series of sub-libraries is created, each containing all the variations in substituents at all but one of the positions. Each sub-library is then divided into a series of aliquots so that each of the values of the remaining substituent may then be introduced individually, to create a set of parallel sub-libraries. Each of these may then be screened, to identify which of the values of each of the variables is responsible for activity.
Deconvolution of combinatorial libraries and sub-libraries may also be assisted by applying analytical techniques conventionally used for resolving mixtures of compounds. In particular, consecutive HPLC, using a series of different columns and different eluants, in combination with mass spectrometry may allow identification of individual members of a library.
For resin libraries, "hit" identification may also be effected by encoding for each of the members of a library with a unique marker, for instance the binary tagging system described by Wigler M et al, Proc Nat Acad Sci USA, 1993, 90, 10922-10926 and in WO 94/08051.
In addition, the compounds of a library may be screened whilst still attached to a resin, for instance beads. In particular, single bead screening may be used. Accordingly, in a further aspect, the present invention provides for a library consisting of n compounds of Formula IV wherein each resin bead has substantially a single compound, the beads being disposed in an array of single beads, the size of the array being choosen so that statistically there is at least a 90% probability, preferably at least a 95% probability that the array will contain a representative of each member of the library present. Suitably, for a 95% probability, 3n beads are arrayed.
Each member may remain bound to the bead or the member may be chemically cleaved from the resin using known cleavage methods and then screened. Generally, screening involves arranging each of the individual beads into a single well of a multiple well microtiter plate. Then, in each well, the compound is released from the bead using known cleavage methods, after which a receptor binding assay or any other known bioassay (for example, one which determines inhibition of a target enzyme) is performed. If a bioactive compound member of the library is found as a result of the screening procedure, identification of that compound is made using traditional methods of structure elucidation, particularly, mass spectrometry and nuclear magnetic resonance spectroscopy. The bead may be subjected to conditions which effect either total or partial cleavage of the library member from the bead. Partial cleavage, sometimes referred to as "shaving" allows the bead to be reused for further assays or, if a hit is given, identification of the compound.
It is expected that, in general, the hits thus obtained will not have sufficient biological activity to be of therapeutic interest. However, chemical elaboration of such hits is expected to provide a compound suitable for development as a therapeutic agent. Further compounds may be prepared as a combinatorial library or an arrays of compounds, by parallel synthesis, as well as more conventional single compound synthesis.
The above specification and Examples fully disclose how to make and use the compounds of the present invention. However, the present invention is not limited to the particular embodiments described hereinabove, but includes all modifications thereof within the scope of the following claims. The various references to journals, patents and other publications which are cited herein comprise the state of the art and are incorporated herein by reference as though fully set forth. | The present invention relates to libraries of compounds based upon a N-(4-alkoxyphenyl)-N-acyl-benzylamine, N-(4-alkoxyphenylmethyl)-N-acyl-benzylamine and N-[2-(4-alkoxyphenyl)ethyl]-N-acyl-benzylamine template, to processes for the preparation of such libraries and their use as a screening tool in biological assays for identifying new chemical leads. | 2 |
BACKGROUND OF THE INVENTION
The present invention relates generally to infrared thermometers and more particularly relates to improvements to ratio type infrared thermometers that determine the temperature of a remote object by measuring power emitted by the object in two different infrared wavebands.
Some ratio type infrared thermometers utilize two infrared sensitive photodetectors that function as a current source and that generate an output current which is a known function of the power incident on the photodiode. Other thermometers utilize different types of IR detectors.
One type of detector used in ratio type thermometers is a sandwich detector having two silicon photodiodes inside. A top diode is a very thin diode and is assembled over the bottom diode. The top diode, in addition to functioning as a photodiode, also functions as an optical filter to absorb IR radiation of selected wavelengths, e.g., short wavelengths, from reaching the bottom diode. Thus, the radiation reaching the bottom diode will have a different spectral composition than the radiation incident on the top diode. Therefore, the top and bottom diodes respond to radiation in two different wavebands.
Some existing ratio thermometers utilize logarithmic amplifiers to handle the large dynamic range of the photodiode detectors. The gain of the logarithmic amplifier is very dependent on the ambient temperature; however, because the algorithm for determining temperature uses the ratio of the outputs of the two amplifiers, the ambient temperature dependence is cancelled if the two amplifiers are at the same ambient temperature.
An advantage of a ratio thermometer is the ability to determine the temperature of a target object if the target is partially obscured and does not fill the field of view of the instrument or if the target is obscured in other ways, e.g., by a dirty window or particles floating in the air.
In a single waveband detector it is assumed that the target is a black body which completely fills the field of view, and the temperature is calculated accordingly. If the target were partially obscured then the radiation emitted would be decreased and the instrument would calculate a temperature that is lower than the actual temperature.
A ratio type thermometer will determine the correct temperature if the two IR wavebands are obscured the same amount and the obscuring artifact is not "colored" to selectively absorb certain IR wavelengths. However, even when using ratio detection it is possible that temperature measurement errors will exceed acceptable limits if too much of the target is obscured. Some existing ratio thermometers sense when the detector output signal level falls below a set magnitude or the attenuation exceeds a preset limit to display an error message and to shutdown to avoid taking erroneous measurements.
SUMMARY OF THE INVENTION
According to one aspect of the present invention, an improved ratio type infrared thermometer provides precise digital representations of the magnitude of the power incident upon the first and second detectors. These signals may be processed using any desired algorithm to determine the temperature of a target object.
According to another aspect of the invention, integrating amplifiers are coupled to the detectors to generate output signal voltage levels to be converted to a digital representation. The amplifiers are coupled to a timing unit that automatically and precisely controls the integration time to utilize the full resolution of an analog to digital convertor.
According to a still further aspect of the invention, the same time of integration is used for both integration channels to increase linearity.
According to a still further aspect of the invention, the non-linearities due to the photodetector diodes are corrected utilizing optical and digital signal processing techniques. Calibration data for each photodiode are stored in a look-up-table (LUT) and utilized to correct the digitized outputs from photodiode channels to provide nearly ideal output signals from each photodiode that can be utilized to calculate temperatures of colored target objects.
According to a still further aspect of the invention, new algorithms or calibration data can be downloaded into the ratio type thermometer by a user to customize or update the instrument.
According to a still further aspect of the invention, an attenuation warning signal is generated when the attenuation of the radiation emitted by the target object exceeds a warning level but the temperature continues to be measured until the attenuation factor exceeds a level sufficient to cause temperature measurement errors to exceed acceptable limits.
Other features and advantages of the invention will become apparent in view of the following detailed description and appended drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a high-level block diagram of a preferred embodiment of the invention;
FIG. 2 is a schematic diagram of the photodiode channels;
FIGS. 3A-B are cross-sectional diagrams of the ratio themometer instrument;
FIG. 4A is a set of graphs depicting the variations in sensitivity on the receiving surface of a photodiode;
FIG. 4B is a set of graphs depicting the non-linear effect of temperature variation;
Fig. S is a set of graphs depicting the non-linear response of a photodiode;
FIG. 6 is a flow chart of a calibration procedure;
FIG. 7 is a flow chart of a correction procedure;
FIG. 8 is a flow chart of the downloading and updating procedure;
FIG. 9 is a flow chart of an attenuation warning procedure; and
FIG. 10 is a plan view of the rear panel.
DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 is a block diagram of a preferred embodiment of the system. The novel functions of various blocks will be described in detail below and those parts of the block diagram not relevant to the present invention will not be described in detail.
Referring to FIG. 1, the top and bottom photodiodes 10 and 12 are coupled to the dual integration amplifiers in module 20. The outputs of the integration amplifier are coupled to comparators 22 and 24 and to an ADC 26 through an MUX 28. The output of the ADC 26 and comparators 22 and 24 are coupled to inputs of a first programmable logic device (PLD) 30. A temperature control system 31 maintains the photodiodes 10 and 12 at a constant temperature.
A digital signal processor (DSP) 40 has its data and address ports coupled to the first PLD 30, a second PLD 42, a FLASH-ROM 44, and a UART 46 by data and address buses (DATA and ADD) 48 and 50. The Tx and Rx ports of UART 46 are coupled to an RS 485 port 52.
The FLASH-ROM includes an output enable (OE) signal input coupled to an OE signal output of the second PLD 42. A logical control input of the second PLD 42 is coupled to a jumper connection 54.
FIG. 2 is a schematic diagram of the integration amplifier and timing unit utilized to generate digital representations of the magnitude of the detector output current signal. In FIG. 2, a first photodiode channel is depicted with the first photodiode 10 coupled to the inverting input of integrating amplifier 60. Integrating amplifier 60 includes a reset switch 62.
The output (VOUT) of the integrating amplifier 60 is coupled to the input of a sample and hold (S/H) circuit 64 and to an input of a comparator 66 having a second input coupled to VREF. The output of the comparator 66 is coupled to the data (D) input of a timing flip-flop (FF) 68 and the output of the S/H circuit 64 is coupled to the input of an analog to digital convertor (ADC) 26 through the MUX 28. A system clock signal (SCLK) is coupled to the clock input of the timing FF 68 and of a counter 72. The D output of the timing FF 68 outputs a timing signal and is coupled to the reset switch 62, the strobe input of the S/H circuit 64, and RESET/LATCH input of the counter 72.
The operation of the first photodiode channel will now be described. As is well-known, the integrating amplifier 60 integrates the input signal when the reset switch is closed. The gain of the amplifier is a function of the time of integration (T). Thus, the output voltage level is a measure of the amplitude of the input current signal if the time of integration is known.
The time of integration is determined by the comparator 66, timing FF 68 and SCLK. In addition to determining the time of integration the voltage level at which integration is terminated is determined by the magnitude of VREF. When VOUT exceeds VREF the comparator output is set. The timing signal generated by the timing FF 68 is then set in synchronism with the next SCLK pulse causing the counter to latch the number of SCLK cycles generated during the time of integration to precisely measure T. Additionally, the setting of the timing signal by the timing FF 68 causes the S/H circuit 64 to latch VOUT at time T and resets the integrating amplifier 60.
To further increase the accuracy of measurement the level of VREF is selected to be in the upper range of dynamic range of the ADC 26 to utilize the full range of the ADC 26. Additionally, because the counter output is not used as an indication of the magnitude of VOUT, a high frequency SCLK signal or a precise VREF is not required. The counter gives a precise measure of the absolute value of T which is used to accurately scale the output of the ADC 26 so that the digital representation indicates the magnitude of the input current signal generated by the first photodiode 10.
The integration and timing unit depicted in the top part of FIG. 2 is coupled to the output of a first photodiode 10. The bottom part of FIG. 2 depicts a second photodiode channel with a second photodiode 12 coupled to second integration circuit including a second integrating amplifier 60a, second comparator 66a, and second S/H circuit 64a. The output of the second S/H 64a circuit is coupled to the ADC 26 through the MUX 28.
The outputs of the first and second comparators 64 and 64a are coupled to the D input of the timing FF 68. Thus, the timing FF 68 triggers the timing signal when VOUT from either the first or second integrating amplifier 60 or 60a exceeds VREF. The timing signal output by the timing FF 68 is used to strobe the first and second S/H circuits 64 and 64a to hold the first and second VOUT signals, respectively, at time T and to reset the first and second integrating amplifiers 60 and 60a. Control signals switch the MUX 28 to alternately provide the VOUT signals from the first and second S/H circuits 64 and 64a to the ADC 70.
Thus, separate digital representations of the output current signals generated by the first and second photodiodes in response to different IR wavebands of the radiation emitted by a single target object are provided at the same time. The integrating amplifiers are not ambient temperature dependent so each representation is an accurate measure of the amplitude of the corresponding output current signals and can be processed to determine the temperature of the target objects.
Because the outputs of both comparators 64 and 64a are coupled to the D input of the timing FF 68, the same integration time, T, is used for both photodiode channels. The use of the same time of integration reduces the effects of non-linearity in the integration period. Also, since the attenuation of the two channels may be time dependent the use of the same time of integration provides for the simultaneous measurement of the two detector signals.
Non-linearities are also caused by the physical characteristics of the photodiode detectors 10 and 12. In the preferred embodiment the digital signals output by the first and second channels are linearized so that the first and second photodiodes function as radiometers in the form of ideal photodiodes. In an ideal photodiode the magnitude of output current (milliamps) is proportional to the magnitude of input power (watts/m 2 ). The linearization of the photodiode output is accomplished through a combination of optical and digital signal processing procedures.
Turning first to the optical procedures, FIGS. 3A and B depict the optical system utilized in the preferred embodiment. In FIG. 3A, a cylindrical housing 90 has an eyepiece aperture 92 at a proximal end 94 and an optical window 96 at a distal end 98. Incoming radiation passes through an achromat 100, a beamsplitter 102, and eyepiece lenses 104 and 106. The beamsplitter 102 deflects a portion of the incoming radiation onto an optical fiber 108 which guides the deflected radiation to a sensor assembly 110 including the first and second photodiode detectors 10 and 12.
The operation of the infrared optics will now be described with reference to FIG. 3B. One cause of non-linearity are chromatic aberration effects. These effects due to the fact that, in a sense, two images of the target object are being measured, one in each of the two wavebands. The achromat 108 is specifically optimized for the two wavebands to limit the effect of chromatic aberrations.
Another cause of non-linearity are variations in the detector's responsivity across its sensitive area, where, in this case, both detectors 10 and 12 in the "detector sandwich" have this variation. This effect is depicted in FIG. 4A. The optical fiber 108 used in the preferred embodiment is a randomizing optical fiber including a large number of fine fibers mixing the image. The result is that any image upon any part of the measurement aperture will illuminate the entire sensitive area of the detector, greatly reducing the effects of the non-uniform response across the sensitive area of the detectors.
Another cause of non-linearity, depicted in FIG. 4B, is the temperature dependent responsivity of the photodiode detectors. In the preferred embodiment this dependence is controlled by temperature compensation system 31 which heats the photodiodes to about 65 degrees Centigrade to a stability of ±0.1 degrees C. Alternatively, the temperature could be measured and corrections applied digitally.
Another cause of non-linearity is due to the nonlinear output of a real photodiode when used over a broad dynamic range. This non-linear response is illustrated by the graphs in FIG. 5. A generic correction is inadequate because there is a significant difference in the non-linear characteristics of each detector.
FIG. 6 is a flow chart of a procedure for generating a correction look-up table (LUT) for a photodiode detector. The detector is exposed to a known incident power 120, the photodetector output is measured and recorded 122, and the measurements are continued over the full dynamic range 124 and 126. A correction LUT is formed 128 in the FLASH-ROM 44 having the actual photodiode digital output signals as address inputs and having the ideal photodiode response for the corresponding incident power stored at the addressed location.
The procedure for utilizing the correction LUT to linearize the digital representations output by the first and second photodiode channels is depicted in FIG. 7. The digital output of the ADC 26 is applied 130 to the LUT and the output signal of the LUT is provided 132 to the user through the serial interface.
Additionally, the linearized output values stored in the LUT are utilized 133 internally by the DSP 40 to calculate the temperature a target object and the attenuation factor.
Thus, digital signals emulating the response of an ideal photodiode responding the images of the target object are provided to the user. In some cases these signals can be successfully used to measure the temperature of a "colored" selectively absorbing surface that cannot be accurately measured by the ratio technique. Such applications are not uncommon in the metal or semiconductor industries and it would be a significant benefit if these measurement problems could be solved.
Many special algorithms have been developed for combining signals from plural detectors to compute surface temperature for specific applications. Some of these algorithms have been published and many are kept secret. Thus, the provision of highly linear signals from two detectors operating in different wavebands will provide the necessary information to utilize these algorithms and other algorithms to be developed.
In the preferred embodiment, the S/H circuits 64 and 64a, timing FF 68, and counter 72 are implemented on the first PLD 30 (FIG. 1). The separate linearized digital output signals are provided serially by the UART 46 and RS485 port 52.
Referring back to FIG. 1, the DSP 40 includes onboard RAM which can be used either as program memory or for data storage and an onboard ROM that holds a bootstrap program. The DSP 40 includes data and address inputs coupled, respectively, to the DATA bus 48 and ADD bus 50.
The FLASH-ROM 44 also includes data and address ports coupled to the DATA and ADD buses 48 and 50 and an output enable (OE) signal input. The FLASH-ROM is used to hold program and calibration data.
The second programmable logic device (PLD) 42 is coupled to selected lines of the ADD and DATA buses and also receives control signals from the DSP 40. The second PLD 42 has a logical control input coupled to the "programming jumper" 54 which is a switchable connection from the control logical input to ground.
The operation of a program downloading and updating system will now be described with reference to the flow chart depicted in FIG. 8. Normally, the jumper switch 54 is open and the logical control input is coupled to a high level through a pull-up resistor so that the second PLD 42 asserts the OE signal.
In that case, after RESET 170, the internal ROM on the DSP 40 is enabled and a small bootstrap program which can load an application from different sources is executed 172. Part of this program after RESET is to read 174 a special location in the FLASH-ROM 44 and to test 176 whether the external FLASH-ROM has a special signature word stored at a special location. If the test is passed then a certain range of the external FLASH-ROM is loaded 178 into the internal RAM of the DSP which is then configured as program memory and executed. This is the "normal" procedure after RESET.
If the special signature word is not read from the special location in the FLASH-ROM 44 then a program is not loaded from the external FLASH-ROM 44 and an asynchronous serial input on an input pin is emulated 180. A program can be downloaded 182 from an external source via this serial input into the RAM of the DSP which is configured as program memory. This is the download mode after RESET and is entered when the FLASH-ROM is empty because the special code will not be found at the special location when the test program is executed. The downloaded program can communicate with a PC to receive data for burning into the FLASH-ROM. The download mode is used during manufacture to download the program code and the calibration data.
The programming jumper 54 allows a special program to be downloaded or the FLASH-ROM 44 to be updated subsequent to the initial burn-in of the FLASH-ROM 44. If the programming jumper 54 is closed, the input signal to the logical control input of the second PLD 42 is low and the OE signal is held low while the test program first accesses the special location so that the special signature word cannot be read from the FLASH-ROM 44 even if it is stored there. Since the special signature word is not found the test program goes into the download mode where a serial download of a program is expected so that a program to overwrite the FLASH-ROM 44 can be downloaded. Once two accesses to the FLASH-ROM 44 by the DSP 40 have been attempted after RESET, the second PLD 42 is programmed to assert the OE signal regardless of the condition of programming jumper 54 to enable reading of the FLASH-ROM 44 for test purposes. It is only the access to the special location that must be blocked to enable the download mode.
A procedure executed by the DSP to generate an attenuation warning signal will now be described with reference to FIG. 8. In FIG. 8, the temperature of the target object is computed 190 using the ratio of the two photodiode output signal levels generated in response to the radiation emitted by the target object in first and second IR wavebands. The radiation that would be emitted by a black body at the computed temperature is calculated, and the unattenuated signal level that would be generated by the black body completely filling the imaging aperture is computed 192. The calculated unattenuated signal level is divided by the actual signal level generated to calculate 194 an attenuation factor.
For example, in the preferred embodiment the instrument is capable of calculating accurate temperature levels up to a failure attenuation factor of about of 100:1. However, the calculated attenuation factor is compared 196 to preset attenuation factors and a relay attenuation alarm is signaled 198 when the calculated attenuation exceeds a warning attenuation factor of 20:1 to allow a user to take remedial action, such as cleaning dirty windows, to avoid failure or a shutdown situation while the instrument continues to output an accurate temperature reading.
If the calculated attenuation factor exceeds the failure attenuation factor then a failure alarm is signaled 200 indicating that the instrument can no longer output accurate temperature reading.
Additionally, the magnitude of the calculated attenuation factor may be output through the serial interface 48 and 50 so that the user can determine whether to take remedial action to lessen the attenuation.
FIG. 10 depicts the rear panel 250 formed on the proximal end 94 of the tubular housing of the instrument. The eyepiece 92 is disposed in the center of the panel 25. A display 252, mode, setup, up, and down switches 254-260, and centigrade (C), fahrenheit (F), Ratio/emissivity (R/e), peak hold (P), average (A), two color (2C), one color wide (1CW), one color narrow (1CN) 262-276 are disposed on the panel. A twelve pin serial data connection and an analog connection (not shown) are disposed on the tubular body. In one mode both the ratio temperature and single detector temperature can be output through the serial data connection. The display 252 can be toggled between two temperatures.
The invention has now been described with reference to the preferred embodiments. Alternatives and substitutions will now be apparent to persons of skill in the art. Accordingly, it is not intended to limit the invention except as provided by the appended claims. | An improved ratio type infrared thermometer utilizes integrating amplifiers for each waveband having the integration time automatically set so that the output voltage utilizes the full range of an analog to digital convertor. The gain and offset of the amplifiers is not ambient temperature dependent so accurate digital representations of the signal for each waveband are provided. The linearized output of each detector is optionally provided so that special or proprietary algorithms for computing the temperature of colored objects can be utilized. A special feature for downloading of updated new programs utilizes a "programming jumper" and an attenuation warning signal is provided for selected levels of attenuation. | 6 |
FIELD OF THE INVENTION
[0001] The present application relates to the mechanical field, specifically to the valve actuation technology for vehicle engines, particularly to method and apparatus for resetting valve lift for an engine brake.
BACKGROUND OF THE INVENTION
[0002] In the prior art, the engine brake technology is well known. Engine braking can be achieved by temporarily converting the engine into a compressor. In the conversion process, the fuel is cut off, and the exhaust valve is opened near the end of the compression stroke of the engine piston, thereby allowing the compressed gases (being air during braking) to be released. The energy absorbed by the compressed gas during the compression stroke of the engine cannot be returned to the engine piston in the subsequent expansion stroke, but is dissipated by the engine exhaust and cooling systems. The above process finally results in an effective engine braking and the slow-down of the vehicle.
[0003] The engine brake includes Compression Release Brake and Bleeder Brake. In an engine using the Compression Release Brake, the exhaust valve is opened near the end of the compression stroke of the engine piston, and is closed after the compression stroke (during the early stage of the expansion or power stroke, prior to the normal opening of the exhaust valve). In an engine using the Bleeder Brake, the exhaust valve is kept slightly open with a constant lift in addition to the normal exhaust valve opening during a part of the engine cycle (Partial Cycle Bleeder Brake) or during the non-exhaust stroke (i.e. the intake stroke, the compression stroke and the expansion or power stroke) of the engine cycle (Full Cycle Bleeder Brake). The main difference between the Partial Cycle Bleeder Brake and the Full Cycle Bleeder Brake is that the former does not open the exhaust valve during most of the intake stroke.
[0004] An example of a conventional engine brake device is a hydraulic-type engine brake provided by Cummins in the disclosure of U.S. Pat. No. 3,220,392 in 1965. In the conventional engine brake, a mechanical input is transmitted to an exhaust valve to be opened through a hydraulic circuit. A master piston reciprocating in a master piston bore is located in the hydraulic circuit. The reciprocating motion comes from the mechanical input of the engine, such as the motion of the engine's fuel injection cam or the neighboring exhaust cam. The motion of the master piston is transmitted through hydraulic fluid to a slave piston located in the hydraulic circuit, causing the slave piston to reciprocate in a slave piston bore. The slave piston acts, directly or indirectly, on the exhaust valve, thereby generating the valve event for the engine braking operation.
[0005] The engine brake device disclosed by Cummins is a bolt-on accessory that fits above the engine. In order to mount the engine brake, a spacer needs to be provided between the cylinder and the valve cover, such that the height, weight and cost of the engine are additionally increased. Obviously, the solution to the above problems is to integrate the components of the braking device in the existing components of the engine, such as in the rocker arm or in the valve bridge of the engine, thereby forming an integrated brake. The integrated engine brakes in the prior art have the following forms.
1. Integrated Rocker-Arm Brake
[0006] An integrated compression release engine brake system was disclosed by Jonsson in U.S. Pat. No. 3,367,312 in 1968. The brake system is integrated in a rocker arm of the engine, and a plunger or a slave piston is positioned in a rocker-arm cylinder arranged at one end, close to an exhaust valve, of the rocker arm and is locked in a protruding position hydraulically, such that a cam motion can be transmitted to one exhaust valve (there is only one valve per cylinder in an early engine) to generate the engine braking operation. As disclosed by Jonsson, a spring is provided for biasing the plunger outward from the cylinder to be in continuous contact with the exhaust valve so as to allow the cam-actuated rocker arm to operate the exhaust valve in both the power and braking modes. In addition, a control valve is used to control the flow of pressurized fluid to the rocker-arm cylinder so as to realize selective switching between a braking operation and a normal power operation.
[0007] A different integrated rocker-arm brake was disclosed by the Mack Truck Company of the United States in U.S. Pat. No. 3,786,792 in 1974. The braking piston of the brake system is positioned in a rocker-arm cylinder arranged at one end, close to a push rod, of the rocker arm and is hydraulically locked in the protruding position, such that the motion of the cam is transmitted to an exhaust valve (there is only one valve per cylinder in an early engine) to produce the engine braking operation. A conventional cam lobe and a braking cam lobe are integrated in the above cam. The brake control valve mechanism (a combination of a funnel-shaped plunger valve and a one-way ball valve) in the above brake system was widely used after its disclosure.
[0008] Another integrated rocker-arm brake is disclosed by the Jacobs Company (JVS) of the United States in U.S. Pat. No. 3,809,033 in 1974. The braking piston of the brake system is positioned in a rocker-arm cylinder arranged at one end, close to the valve bridge, of the rocker arm, and is movable between a non-braking position and a braking position. In the braking position, the braking piston is hydraulically locked in a protruding position, such that the cam motion is transmitted to the valve bridge to open two exhaust valves (the engine has two valves per cylinder) for producing the engine brake operation. The braking system uses two separate oil passages, one for supplying oil to the brake, and the other being a conventional engine lubrication oil passage.
[0009] An integrated rocker-arm brake system for an overhead cam four-valve engine was disclosed by Sweden's Volvo Company in U.S. Pat. No. 5,564,385 in 1996, which is very similar in both structure and principle to the integrated rocker-arm brake disclosed by Jacobs Company (JVS) in U.S. Pat. No. 3,809,033 in 1974. The hydraulic braking piston is positioned in a rocker-arm cylinder arranged at one end, close to the valve bride, of the rocker arm and is movable between a non-braking position and a braking position and forms a gap in the engine air valve system. Oil with a certain pressure is supplied to the braking piston by a pressure control valve to fill the gap in the rocker arm so as to form a hydraulic linkage. The engine braking system adopted the combined structure having a funnel-shaped plunger valve and a one-way ball valve and added an overload pressure relief mechanism, and an oil supply device for providing dual oil pressures via a single oil passage, wherein a low oil pressure (below the engine lubricating oil pressure) is used for the engine lubrication, and a high oil pressure (equal to the engine lubricating oil pressure) is used for the engine brake. During engine braking, the braking piston drives the valve bridge to open the two exhaust valves simultaneously.
[0010] Another new integrated rocker-arm brake was disclosed by the Mack Truck Company of the United States in U.S. Pat. No. 6,234,143 in 2001, which is quite different from the technology disclosed in U.S. Pat. No. 3,786,792 in 1974. First of all, an Exhaust Gas Recirculation (EGR) cam lobe was added to the integrated cam formed with the conventional cam lobe and the braking cam lobe, which facilitates improving the braking power. Secondly, the engine with a single valve per cylinder is changed into an engine with dual valves per cylinder, and a valve bridge (an air valve bridge or a cross arm) was added. Further, the braking piston in the rocker-arm piston bore is moved from the push rod side to the valve bridge side, and is located above the exhaust valve (an inner valve) next to the rocker-arm shaft. During braking, the braking piston opens one exhaust valve via a braking top block or by a direct action on the valve bridge. However, since only one valve is opened for braking, the valve bridge is in an inclined state and an asymmetric load is generated on the valve bridge and the rocker arm. Furthermore, the braking valve (the inner valve) lift profile is greater than the non-braking valve (an outer valve) or the conventional valve lift profile (larger opening and later closing).
[0011] An integrated rocker-arm brake system having a valve lift reset mechanism was disclosed by Cummins Engine Company in U.S. Pat. No. 6,253,730 in 2001 to resolve the problems of the one-valve (the inner valve) braking, such as the asymmetric load and the braking valve (the inner valve) lift profile being greater than the non-braking valve (the outer valve) or the conventional valve lift profile (larger opening and later closing). The valve lift reset mechanism resets or retracts the braking piston in the rocker arm before the braking valve reaches its peak valve lift, which allows the braking valve to return to the valve seat before the start of the main valve action, such that the valve bridge returns to the horizontal position, and the rocker arm can open the braking valve and the non-braking valve evenly, thereby eliminating any asymmetric load.
[0012] However, there are a lot of problems with resetting the engine braking system before the braking valve reaching its peak valve lift. Firstly, during engine braking, both the opening time and the lift magnitude of the braking valve are very short, thus the time for resetting is very limited. Secondly, the resetting occurs when the engine braking load is close to the maximum (i.e. the top dead center of the compression stroke), thereby causing the reset valve of the valve lift reset mechanism to bear a high oil pressure or a large load. Thus, the engine brake resetting timing is essential. If the resetting occurs too early, the loss of braking valve lift is too much (causing a lower valve lift and the valve to be closed too early), which may reduces the braking performance. If the resetting occurs too late, the braking valve can not be closed before the start of the main valve action, which may results in an asymmetric load. Tests show that the integrated rocker-arm brake cannot work properly at high engine speeds, because the resetting time is too short, the resetting height is too small, and the load or pressure on the reset valve is very high.
2. Integrated Valve Bridge Brake
[0013] An example of a conventional integrated valve bridge brake was disclosed by Calvin in U.S. Pat. No. 3,520,287 in 1970. The entire valve bridge is set on a central guide rod. The guide rod is provided with an internal brake oil passage and a control valve. An upper portion of the guide rod acts as a braking piston, the valve bridge slides along the braking piston through a piston bore in the valve bridge. The disadvantage of this apparatus is that there is always a large relative motion between the braking piston and the piston bore in the valve bridge.
[0014] An improved valve bridge brake mechanism was disclosed by Sickler in U.S. Pat. No. 4,572,114 in 1986. A dedicated braking piston is housed in a piston bore opened upward at the center of the valve bridge, such that the relative motion between the braking piston and the valve bridge is greatly reduced. The valve bridge brake mechanism was designed for a four-stroke engine, but each engine cycle produces two compression release braking events.
[0015] Recently, the Jacobs Company (JVS) of the United State designed and manufactured a valve bridge brake device (see U.S. Publication No. 20050211206 and No. 20070175441) for Hyundai Truck Company in South Korea. Wherein, a valve lift reset mechanism was added to the valve bridge brake mechanism disclosed by Sickler in U.S. Pat. No. 4,572,114 in 1986. But similar to the valve lift reset mechanism disclosed by Cummins Engine Company in U.S. Pat. No. 6,253,730 in 2001, the reset valve of the valve lift reset mechanism is located in the exhaust valve actuator (in the rocker arm for Cummins and in the valve bridge for JVS), while the reset top block or the reset rod is located on the engine, such that it is very difficult to ensure the height and timing for resetting the braking valve lift, and it is also not convenient for installation, transportation and adjustment.
SUMMARY OF THE INVENTION
[0016] An object of the present application is to provide a method for resetting a valve lift for an integrated engine brake, so as to solve technical problems of a valve lift reset device of an integrated engine braking in the prior art, such as having a poor precision and being inconvenient for installation and adjustment.
[0017] The method of the present application for resetting a valve lift of an integrated engine brake includes a process of utilizing a motion of a cam to open an engine exhaust valve through a rocker arm and a valve bridge of an engine, wherein the rocker arm or the valve bridge is provided with a braking piston and a hydraulic flow passage, and the braking piston is connected to the hydraulic flow passage, a valve lift reset mechanism is provided between the rocker arm and the valve bridge and includes a reset valve, and a reset flow passage located in the rocker arm or the valve bridge, wherein the process includes the following steps: placing the braking piston at an extended position by supplying pressure to the hydraulic flow passage, providing a reset valve between the rocker arm and the valve bridge, connecting the reset valve to a reset flow passage located in the rocker arm or the valve bridge, connecting the reset flow passage to the hydraulic flow passage, utilizing a change of a distance between the rocker arm and the valve bridge to open and close the reset valve, opening the reset valve when a valve lift of the engine exhaust valve enters into its top portion, releasing hydraulic pressure in the hydraulic flow passage through the reset flow passage, retracting the braking piston by a gap, eliminating a part of a motion transmission between the cam and the engine exhaust valve, reducing the valve lift of the engine exhaust valve, and during a returning process of the valve lift of the engine exhaust valve after passing its maximum position, closing the reset valve to resume pressure supply in the hydraulic flow passage, placing the braking piston at the extended position, and re-establishing the motion transmission between the cam and the engine exhaust valve.
[0018] Further, the cam is integrated with a braking cam and a conventional cam of the engine, and includes an enlarged conventional cam lobe and at least one braking cam lobe, the enlarged conventional cam lobe generates an enlarged conventional valve lift profile consisted of a bottom portion and a top portion, the bottom portion has approximately the same height as a braking valve lift profile generated by the at least one braking cam lobe, and the top portion is approximately the same as a conventional valve lift generated by a conventional cam lobe of the engine.
[0019] Further, the process of utilizing the motion of the cam to open the engine exhaust valve through the engine rocker arm and the valve bridge includes the following steps:
[0000] 1) the reset valve having an oil-feeding position and an oil-draining position, and at the oil-feeding position, the reset valve closes the reset oil passage; and at the oil-draining position, the reset valve opens the reset oil passage,
2) turning on a brake control mechanism to supply oil to the hydraulic flow passage,
3) positioning the reset valve at the oil-feeding position, closing the reset oil passage, and the braking piston being located at the extended position,
4) rotating the cam from an inner base circle toward the at least one braking cam lobe,
5) transmitting a motion from the at least one braking cam lobe of the cam to at least one exhaust valve through the rocker arm, the valve bridge and the braking piston,
6) rotating the cam over a bottom portion of the enlarged conventional cam lobe and upward to a top portion of the enlarged conventional cam lobe, driving the rocker arm to rotate clockwise and the valve bridge to make a downward translational motion, changing the distance between the rocker arm and the valve bridge, changing the reset valve from the oil-feeding position to the oil-draining position due to the change of the distance between the rocker arm and the valve bridge, opening the reset oil passage to drain oil, moving the braking piston in the exhaust valve actuator from the extended position to the retracted position, a part of a motion from the top portion of the enlarged conventional cam lobe of the cam being lost, and resetting the enlarged conventional valve lift profile generated by the enlarged conventional cam lobe to a conventional valve lift profile generated by the conventional cam lobe of the engine,
7) rotating the cam over the highest position of the enlarged conventional cam lobe and downward to the bottom portion of the enlarged conventional cam lobe, driving the rocker arm to rotate anticlockwise and the valve bridge to make an upward translational motion, changing the distance between the rocker arm and the valve bridge in an opposite way as in step 6), moving the reset valve from the oil-draining position back to the oil-feeding position due to the opposite change of the distance between the rocker arm and the valve bridge, closing the reset oil passage again, moving the braking piston in the exhaust valve actuator from the retracted position back to the extended position, and transmitting the motion from the at least one braking cam lobe of the cam to the exhaust valve through the exhaust valve actuator and the braking piston,
8) returning the cam to the position as in step 6), and starting a next braking cycle until the brake control mechanism is turned off with oil being discharged from the hydraulic flow passage and an engine braking operation being turned off.
[0020] The present application also provides a valve lift reset device for an integrated engine brake, including a cam, a rocker arm and a valve bridge of an engine, the rocker arm or the valve bridge being provided with a braking piston and a hydraulic flow passage, the braking piston being connected to the hydraulic flow passage, wherein the cam is integrated with a braking cam and a conventional cam of the engine and includes an enlarged conventional cam lobe and at least one braking cam lobe, a valve lift reset mechanism is provided between the rocker arm and the valve bridge, the valve lift reset mechanism includes a reset valve and a reset oil passage, the reset oil passage is located in the rocker arm or in the valve bridge, the reset valve has an oil-feeding position and an oil-draining position, and at the oil-feeding position, the reset oil passage is closed by the reset valve; and at the oil-draining position, the reset oil passage is opened by the reset valve, and an action of the reset valve is coupled to a distance between the rocker arm and the valve bridge.
[0021] Further, the braking piston is integrated in the rocker arm.
[0022] Alternatively, the braking piston is integrated in the valve bridge.
[0023] Further, the reset valve is one of the following devices or a combination of two or more of the following devices:
[0024] a) a sliding-type plunger valve;
[0025] b) a lifting-type plunger valve;
[0026] c) a lifting-type ball valve;
[0027] d) a lifting-type column valve; and
[0028] e) other devices being able to open and close the reset flow passage.
[0029] Further, the cam includes an enlarged conventional cam lobe and two braking cam lobes.
[0030] The working principle of the present application is as following. The cam, the rocker arm or the valve bridge form an exhaust valve actuator. When the engine braking is required, the engine brake control mechanism is turned on to supply a low pressure engine oil (the engine lubrication oil) to the brake actuation mechanism. The engine oil flows to the braking piston through a fluid network and a one-way valve so as to eliminate a gap formed by the braking piston in the exhaust valve actuator (in the rocker arm or in the valve bridge). At the same time, due to the oil pressure, the reset valve of the valve lift reset mechanism is placed at the oil-feeding position to close the reset oil passage. When the cam rotates to the braking cam lobe from the inner base circle, the motion from the braking cam lobe is transmitted to the exhaust valve through the exhaust valve actuator and the braking piston. The cam continues to rotate from the bottom portion to the top portion of the enlarged conventional cam lobe, so as to drive the rocker arm to rotate clockwise and the valve bridge to make a downward translational motion, thereby causing the change of the distance between the rocker arm and the valve bridge, which in turn changes the reset valve of the valve lift reset mechanism, provided between the rocker arm and the valve bridge, from the oil-feeding position to the oil-draining position. The reset oil passage is opened to drain oil, and the braking piston in the exhaust valve actuator is moved from the extended position to the retracted position, such that a part of the cam motion from the top portion of the enlarged conventional cam lobe is lost, and the enlarged conventional valve lift profile generated by the enlarged conventional cam lobe is reset to the conventional valve lift profile generated by the conventional engine cam lobe. When the cam rotates over the highest position of the enlarged conventional cam lobe and then moves downward to the bottom portion of the enlarged conventional cam lobe, the rocker arm rotates counterclockwise and the valve bridge makes an upward translational motion, thereby causing an opposite change of the distance between the rocker arm and the valve bridge. Such that, the reset valve of the valve lift reset mechanism between the rocker arm and the valve bridge is changed from the oil-draining position to the oil-feeding position, the reset oil passage is closed again, the braking piston in the exhaust valve actuator is moved from the retracted position to the extended position, and the motion of the braking cam lobe of the cam is transmitted to the exhaust valve through the exhaust valve actuator and the braking piston.
[0031] The above valve lift resetting process is completed in one braking cycle. The braking cycle repeats until the brake control mechanism is turned off. At this time, the brake control mechanism discharges oil (for a three-way solenoid valve) or ceases oil supply (for a two-way solenoid valve). The valve lift reset mechanism drains oil once in each engine cycle, and the oil drained is not supplemented, such that the gap in the valve actuation chain is formed again, and the motion of the braking cam lobe is skipped and will not be transmitted to the exhaust valve. The engine braking operation is turned off and the engine resumes its conventional operation state.
[0032] The present application has positive and significant effects over the prior art. The present application integrates the engine braking function, the valve lift resetting function and the conventional valve lifting function into the existing engine valve actuation chain, thereby forming a compact structure, reducing the weight and height of the engine, simplifying the engine braking device, and improving the safety and reliability of the engine operation.
BRIEF DESCRIPTION OF THE DRAWINGS
[0033] FIG. 1 is a schematic diagram showing a valve lift reset mechanism for an engine brake according to a first embodiment of the present application when the engine brake is at an “OFF” position.
[0034] FIG. 2 is a schematic diagram showing the valve lift reset mechanism for an engine brake according to the first embodiment of the present application when the engine brake is at an “ON” position.
[0035] FIG. 3 is a schematic diagram showing a brake control mechanism at an “ON” position in the valve lift reset mechanism for an engine brake according to the present application.
[0036] FIG. 4 is a schematic diagram showing the brake control mechanism at an “OFF” position in the valve lift reset mechanism for an engine brake according to the present application.
[0037] FIG. 5 is a schematic view of a conventional valve lift profile of an engine exhaust valve and an engine braking valve lift profile according to the present application.
[0038] FIG. 6 is a schematic diagram showing a valve lift reset mechanism for an engine brake according to a second embodiment of the present application when the engine brake is at an “OFF” position.
[0039] FIG. 7 is a schematic diagram showing the valve lift reset mechanism for an engine brake according to the second embodiment of the present application when the engine brake is at an “ON” position.
[0040] FIG. 8 is a schematic diagram showing a valve lift reset mechanism for an engine brake according to a third embodiment of the present application when the engine brake is at an “OFF” position.
[0041] FIG. 9 is a schematic diagram showing the valve lift reset mechanism for an engine brake according to the third embodiment of the present application when the engine brake is at an “ON” position.
[0042] FIG. 10 is a schematic diagram showing a valve lift reset mechanism for an engine brake according to a fourth embodiment of the present application when the engine brake is at an “OFF” position.
[0043] FIG. 11 is a schematic diagram showing the valve lift reset mechanism for an engine brake according to the fourth embodiment of the present application when the engine brake is at an “ON” position.
[0044] FIG. 12 is a schematic diagram showing a valve lift reset mechanism for an engine brake according to a fifth embodiment of the present application when the engine brake is at an “OFF” position.
[0045] FIG. 13 is a schematic diagram showing a valve lift reset mechanism for an engine brake according to a sixth embodiment of the present application when the engine brake is at an “OFF” position.
[0046] FIG. 14 is a schematic diagram showing the valve lift reset mechanism for an engine brake according to the sixth embodiment of the present application when the engine brake is at an “ON” position.
DETAILED DESCRIPTION OF THE EMBODIMENTS
First Embodiment
[0047] Reference is made to FIGS. 1 and 2 , which are schematic diagrams showing a first embodiment of the present application when the engine brake is at the “OFF” and “ON” positions respectively. There are four main parts in FIGS. 1 and 2 , including an exhaust valve actuator 200 , an exhaust valve 300 (including an exhaust valve 3001 and an exhaust valve 3002 ), an engine brake actuation mechanism 100 and a valve lift reset mechanism 150 .
[0048] The exhaust valve actuator 200 includes a cam 230 , a cam follower 235 , a push rod or a push tube 201 (overhead cam engine does not need the push rod or the push tube 201 ), a rocker arm 210 and a valve bridge 400 (an engine with one valve per cylinder does not need the valve bridge 400 ). Generally a valve lash adjusting system is arranged at one end of the rocker arm 210 (one end close to the valve bridge or one end close to the push rod). In the present embodiment, a valve lash adjusting screw 110 and the push rod 201 are connected to form the valve lash adjusting system, and the valve lash adjusting screw 110 is fixed to the rocker arm 210 by a lock nut 105 . On an inner base circle 225 , the cam 230 has an enlarged conventional cam lobe 220 which is mainly used for the conventional operation of the engine, and the reason that the enlarged conventional cam lobe 220 is larger than a conventional exhaust cam lobe (without an engine brake device) is because the braking cam is integrated with the conventional cam. Therefore, the integrated cam 230 is also provided with braking cam lobes 232 and 233 for the engine brake. A height of the braking cam lobes 232 and 233 is about 2 millimeters, which is far below the exhaust cam lobe. A bottom of the enlarged cam lobe 220 must have a transitional portion having about the same height as the braking cam lobes so as to skip the braking cam lobes 232 and 233 during the engine conventional operation (i.e. an ignition operation). A top portion of the enlarged cam lobe 220 is equivalent to the conventional exhaust cam lobe. The braking cam lobe 232 on the cam 230 is used for an Exhaust Gas Recirculation (EGR), and the braking cam lobe 233 is used for compression release. The rocker arm 210 is rotationally mounted on a rocker shaft 205 , and a braking piston 160 is placed in a piston bore at an end, close to the valve bridge 400 , of the rocker arm 210 . The braking piston 160 is connected to an elephant foot pad 114 located at a central position of an upper surface of the valve bridge 400 . The valve bridge 400 lies across the top of two exhaust valves 300 .
[0049] The exhaust valve 3001 and the exhaust valve 3002 are biased onto valve seats 320 in an engine cylinder block 500 via a valve spring 3101 and a valve spring 3102 (the valve spring 3101 and the valve spring 3102 are collectively referred to as valve springs 310 ) respectively so as to prevent gas (being air during the engine braking) from flowing between an engine cylinder and an exhaust manifold 600 . The exhaust valve actuator 200 transmits the mechanical motion of the cam 230 to the exhaust valves 300 via the valve bridge 400 , so as to periodically open and close the exhaust valves 300 .
[0050] The brake actuation mechanism 100 includes the braking piston 160 , the braking piston 160 is slidably disposed in a piston bore 190 of the rocker arm 210 and is movable between an extended position and a retracted position (the position after resetting and oil draining). The braking piston 160 is biased onto a center position of the upper surface of the valve bridge 400 by a preload spring 198 located between the rocker arm 210 and the braking piston 160 . A gap 234 is formed in the exhaust valve actuator 200 by the motion of the braking piston 160 between the retracted position and the extended position, such that the motion from a bottom portion of the cam 230 (including the braking cam lobes 232 and 233 ) will be skipped or lost during the conventional operation of the engine, and will not be transmitted to the exhaust valves 300 . The brake actuation mechanism 100 further includes a one-way valve mechanism for supplying oil to the braking piston 160 . The one-way valve mechanism includes a valve ball 172 , a spring 156 and a spring seat 157 .
[0051] A reset valve of the valve lift reset mechanism 150 is located between the rocker arm 210 and the valve bridge 400 , and includes a reset piston 170 and a reset oil passage 219 which are both located in the rocker arm 210 . A flow area of the reset oil passage 219 is much smaller than an oil inlet flow area. The reset piston 170 is movable between an oil-draining position and an oil-feeding position. In the oil-draining position, the reset valve is in an opened position, and in the oil-feeding position, the reset valve is in a closed position. During the conventional engine operation, the reset piston 170 is biased upward by a spring 166 , and the reset valve is opened at the oil-draining position. One end of the spring 166 is on the valve bridge 400 , and the other end thereof is on a spring seat 167 fixed to the reset piston 170 . A preload force of the spring 166 is very small, which can keep the reset piston 170 in the rocker arm 210 without producing no-follow or impact.
[0052] As shown in FIG. 3 , when the engine braking is required, the brake control mechanism is turned on, such that a solenoid valve 51 may supply oil to the brake actuation mechanism 100 through a brake fluid network. The oil pressure overcomes the force of the spring 156 and opens the one-way valve 172 . The engine oil flows into the piston bore 190 and fills the gap 234 between the braking piston 160 and the rocker arm 210 . At the same time, as shown in FIGS. 1 and 2 , the oil pressure overcomes the force of the spring 166 , and pushes the reset piston 170 from the oil-draining position to the oil-feeding position, thereby closing the reset oil passage 219 . The engine oil forms a hydraulic linkage between the braking piston 160 and the rocker arm 210 . When the cam 230 rotates from the inner base circle 225 to the braking cam lobes 232 and 233 , the motion of the braking cam lobes is transmitted to the exhaust valves 300 through the exhaust valve actuator 200 (through the rocker arm 210 and the valve bridge 400 ) and the braking piston 160 . The cam 230 continues to rotate from the bottom to the top of the enlarged conventional cam lobe 220 , thereby driving the rocker arm 210 to rotate clockwise and the valve bridge 400 to make a downward translational motion, such that a distance between the rocker arm and the valve bridge is changed (other than a contact point of the elephant foot pad 114 and the valve bridge 400 ). A distance (a reset distance) 131 between the reset piston 170 in the rocker arm 210 and the valve bridge 400 is reduced. As shown in FIG. 5 , when the motion of the enlarged conventional cam lobe 220 drives the valve bridge 400 and the exhaust valves 300 to move downward to the lowest position (i.e., the valve lift increases into a top portion, for example, at point 220 r in FIG. 5 ), the valve bridge 400 acts on the reset piston 170 (the reset distance 131 becomes zero) to push it upward in the rocker arm 210 , thereby changing the reset piston 170 from the oil-feeding position to the oil-draining position, then the reset valve is opened and the oil is drained from the reset oil passage 219 . The braking piston 160 in the rocker arm 210 of the exhaust valve actuator 200 is moved from the extended position to the retracted position, a part of the motion from the top portion of the enlarged conventional cam lobe 220 of the cam 230 is lost, and an enlarged conventional valve lift profile 220 e generated by the enlarged conventional cam lobe 220 is reset to a conventional valve lift profile 220 m generated by the conventional cam lobe of the engine.
[0053] When the cam 230 rotates over the highest position of the enlarged conventional cam lobe 220 and rotates downward from the top to the bottom of the enlarged conventional cam lobe 220 , the rocker arm 210 rotates counterclockwise, the valve bridge 400 makes an upward translational motion, and the reset distance 131 is increased. The reset piston 170 under the oil pressure moves downward relative to the rocker arm 210 , and is back to the oil-feeding position from the oil-draining position, and the reset oil passage is closed again by the reset valve. The braking piston 160 in the rocker arm 210 returns to the extended position from the retracted position, and forms the hydraulic linkage again between the braking piston 160 and the rocker arm 210 , so as to transmit the motion from the braking cam lobes 232 and 233 to the exhaust valves 300 .
[0054] The above valve lift resetting process is completed in one braking cycle. The braking cycle repeats until the brake control mechanism 50 is turned off. As shown in FIG. 4 , When the brake control mechanism 50 is turned off, the brake control mechanism 50 discharges oil (for a three-way solenoid valve 51 ) or ceases the oil supply (for a two-way solenoid valve). The valve lift reset mechanism 150 drains oil once in each engine cycle, the oil drained is not supplemented, then the hydraulic linkage between the braking piston 160 and the rocker arm 210 is eliminated, and the gap 234 in the valve actuation chain is formed again. Thus, the motion from the braking cam lobes 232 and 233 is skipped and will not be transmitted to the exhaust valves 300 , the engine braking operation is turned off and the engine resumes its conventional operation state.
[0055] FIG. 3 and FIG. 4 are schematic diagrams of a brake control mechanism at the “ON” and “OFF” positions respectively for an engine brake according to the present application. Since the present application uses a valve lift reset mechanism 150 , the two-position three-way solenoid valve 51 of the brake control mechanism 50 can be simplified to a two-way solenoid valve. In other words, only an oil intake hole 111 is needed, and an oil discharging hole 222 is not needed.
[0056] FIG. 5 is a schematic diagram of a conventional valve lift profile and an engine braking valve lift profile of a valve lift reset mechanism for an engine brake according to the present application. The exhaust valve lift profile further illustrates the operating process of the first embodiment. Three valve lift profiles are shown in the figure.
[0000] 1. A conventional valve lift profile 220 m for the engine's conventional (ignition) operation has a starting point 225 a , an end point 225 b , and a maximum height about 220 b.
2. An enlarged valve lift profile 220 V (including an enlarged conventional valve lift profile 220 e and braking valve lift profiles 232 v and 233 v ) for an engine braking operation without a valve lift reset mechanism has a starting point 225 d , an end point 225 c , and a maximum lift being the sum of 220 a and 220 b . The valve lift profile repeats itself between 0˜720°, with 0° and 720° representing the same point.
3. A valve lift profile with resetting (indicated as the thick solid line in the figure) for an engine braking operation with a valve lift reset mechanism has a starting point 225 d , an end point 225 b , and the maximum lift 220 b . Therefore, the valve lift profile with resetting closes earlier and has a lower lift than the enlarged valve lift profile 220 v.
[0057] As shown in FIGS. 1 and 2 , during the conventional operation of the engine, the bottom portion of the cam 230 (including the braking cam lobes 232 and 233 ) is skipped due to the gap 234 in the exhaust valve actuation chain, only the motion from the top portion of the enlarged conventional cam lobe 220 is transmitted to the valves 300 , thereby producing the conventional valve lift profile 220 m (see FIG. 5 ) which is the same as the conventional valve lift profile of an engine (without an engine brake). A bottom portion 220 a and a top portion 220 b of the enlarged conventional valve lift profile 220 e generated by the enlarged conventional cam lobe 220 have a transition point 220 t . A height 232 p of the bottom portion 220 a is the same as or slightly larger than the braking valve lifts 232 v and 233 v generated by the braking cam lobes 232 and 233 , and the top portion 220 b is substantially the same as the conventional valve lift profile 220 m.
[0058] During the engine braking operation, the mechanical motion generated by the braking cam lobes 232 and 233 as well as the enlarged conventional cam lobe 220 can all be transmitted to the exhaust valves 300 . However, the valve lift profile of the engine braking operation varies depending on the presence or absence of the valve lift reset mechanism 150 . If there is an engine brake reset mechanism 150 (see FIGS. 1 and 2 ), the engine braking valve lift profile before a reset point 220 r (which is between 220 t and 220 e and is higher than the braking valve lifts 232 v and 233 v ) is the same as that without the reset mechanism (see FIG. 5 ). And after the reset point 220 r , the valve is reset from the reset point 220 r on the enlarged conventional valve lift profile 220 e down to a point 220 s on the conventional valve lift profile 220 m , and finally returns to the valve seat at the end point 225 b (i.e. the zero lift end point) which is far ahead of the end point 225 c without the valve lift reset mechanism. Therefore, the valve lift reset mechanism 150 reduces the enlarged conventional valve lift profile 220 e during its top portion to the conventional valve lift profile 220 m . Thus, the valve lift is reduced at the top dead center of the engine piston at 360° to avoid the impact between the valve and the piston, which also increases the braking power and reduces the temperature in the cylinder.
Second Embodiment
[0059] Reference is made to FIGS. 6 and 7 , which are schematic diagrams showing a valve reset mechanism for an engine brake according to a second embodiment of the present application when the engine brake is at the “OFF” and “ON” positions respectively. The major difference between the present embodiment and the first embodiment is that the valve lift reset mechanism 150 in the rocker arm 210 is moved from an outer end close to the braking piston 160 to an inner end between the braking piston 160 and the rocker arm shaft 205 . In addition, the reset valve is changed from a lifting-type plunger valve in the first embodiment to a sliding-type plunger valve in the present embodiment.
[0060] When the engine braking is required, the brake control mechanism is turned on and the solenoid valve 51 supplies oil to the brake actuation mechanism 100 through the brake fluid network. Oil pressure overcomes the force of the spring 166 and pushes the reset piston 170 downward from the oil-draining position to the oil-feeding position to close the reset oil passage 219 . At this time, the valve bridge 400 acts on the reset piston 170 to prevent the reset piston 170 from moving down further in the rocker arm 210 . At the same time, the oil pressure overcomes the force of the spring 156 and opens the one-way valve 172 . Engine oil flows into the piston bore 190 and fills the gap 234 between the braking piston 160 and the rocker arm 210 to form a hydraulic linkage between the braking piston 160 and the rocker arm 210 . When the cam 230 rotates from the inner base circle 225 to the braking cam lobes 232 and 233 , the motion of the braking cam lobes 232 and 233 is transmitted to the exhaust valves 300 through the exhaust valve actuator 200 (through the rocker arm 210 and the valve bridge 400 ) and the braking piston 160 . The cam 230 rotates over the bottom of the enlarged conventional cam lobe 220 , and then moves upward to the top of the enlarged conventional cam lobe 220 , so as to drive the rocker arm 210 to rotate clockwise and the valve bridge 400 to make a downward translational motion, thereby changing the distance between the rocker arm and the valve bridge (except for the contact point of the elephant foot pad 114 and the valve bridge 400 ). The distance (the reset distance) 131 between the reset piston 170 in the rocker arm 210 and the valve bridge 400 is increased. When the motion of the enlarged conventional cam lobe 220 causes the valve bridge 400 and the exhaust valves 300 to move downward to the lowest position (i.e., the valve lift increases and enters into the top, for example, at the point 220 r in FIG. 5 ), the reset piston 170 moves downward with the valve bridge 400 , such that the reset valve in the rocker arm 210 is changed to the oil-draining position, and the reset oil passage 219 is opened to drain oil. The braking piston 160 in the rocker arm 210 of the exhaust valve actuator 200 is moved from the extended position to the retracted position, and a part of the motion from the top portion of the enlarged conventional cam lobe 220 of the cam 230 is lost, thus the enlarged conventional valve lift profile 220 e generated by the enlarged conventional cam lobe 220 is reset and reduced to the conventional valve lift profile 220 m generated by the conventional cam lobe of the engine.
[0061] When the cam 230 rotates over the highest position of the enlarged conventional cam lobe 220 , and moves downward from the top to the bottom of the enlarged conventional cam lobe 220 , the rocker arm 210 rotates counterclockwise, and the valve bridge 400 makes an upward translational motion, thus the reset distance 131 is reduced. Under the action of the valve bridge 400 , the reset piston 170 is moved upward relative to the rocker arm 210 , and then the reset oil passage is closed again by the reset valve. The braking piston 160 in the rocker arm 210 is moved from the retracted position to the extended position, and the hydraulic linkage between the braking piston 160 and the rocker arm 210 is re-established, such that the motion from the braking cam lobes 232 and 233 is transmitted to the exhaust valves 300 .
[0062] The above valve lift resetting process is completed in one braking cycle. The braking cycle repeats until the brake control mechanism 50 is turned off. At this time, the brake control mechanism 50 discharges oil (for a three-way solenoid valve 51 ) or ceases the oil supply (for a two-way solenoid valve). The valve lift reset mechanism 150 drains oil once in each engine cycle, and the oil drained is not supplemented, such that the hydraulic linkage between the braking piston 160 and the rocker arm 210 is eliminated, and the gap 234 in the valve actuation chain is formed again. Thus, the motion from the braking cam lobes 232 and 233 is skipped and will not be transmitted to the exhaust valves 300 , and the engine braking operation is turned off and the engine resumes its conventional operation state.
Third Embodiment
[0063] Reference is made to FIGS. 8 and 9 , which are schematic diagrams showing a valve reset mechanism according to a third embodiment of the present application when the engine brake is at the “OFF” and “ON” positions respectively. An overhead cam engine is provided in the present application, thus there is no push rod or push tube, and the exhaust valve lash adjusting screw 110 is mounted on a side close to the valve bridge 400 . The brake actuation mechanism 100 is integrated in the valve bridge 400 . The braking piston 160 is placed in a piston bore 190 which is an upward opening in the center of the valve bridge 400 . A preload spring 198 provided between the braking piston 160 and the valve bridge 400 biases the braking piston 160 upward against the elephant foot pad 114 . A one-way valve 172 is placed in the braking piston 160 .
[0064] A reset valve of the valve lift reset mechanism 150 is also located between the rocker arm 210 and the valve bridge 400 , and includes a reset piston 170 and a reset oil passage 415 which are both located in the valve bridge 400 . A flow area of the reset oil passage 415 is much smaller than the oil inlet flow area. The reset piston 170 is movable between an oil-draining position and an oil-feeding position. At the oil-draining position (see FIG. 8 ), the reset piston 170 is moved downward to open the reset oil passage 415 , and the oil is discharged through a high pressure oil passage 412 ; and at the oil-feeding position (see FIG. 9 ), the reset piston 170 is moved upward under the oil pressure to close the reset oil passage 415 .
[0065] The valve lift reset mechanism 150 further includes an adjusting screw 1102 fixed by a nut 1052 onto a projecting portion 2102 of the rocker arm 210 . The projecting portion 2102 can also be a separate part fastened on the rocker arm 210 . The adjusting screw 1102 is located above the reset piston 170 for adjusting a reset distance 1312 between the adjusting screw 1102 and the reset piston 170 . The reset distance 1312 is designed, so that when the reset piston 170 is at the oil-draining position (see FIG. 8 ), the reset piston 170 does not contact the adjusting screw 1102 in the entire rotation period of the cam 230 . In this way, the operating frequency of the valve lift reset mechanism 150 is greatly reduced, thereby increasing its reliability and durability.
[0066] When the engine braking is required, the brake control mechanism is turned on. The solenoid valve 51 supplies oil to the brake actuation mechanism 100 through a brake fluid network (see FIGS. 8 and 9 ). The oil flows through the one-way valve 172 and into the piston bore 190 , and the braking piston in the valve bridge 400 is at the extended position. At the same time, oil pressure pushes the reset piston 170 from the oil-draining position (see FIG. 8 ) upward to the oil-feeding position (see FIG. 9 ) to close the reset oil passage 415 , and a hydraulic linkage is formed between the braking piston 160 and the valve bridge 400 by the engine oil. When the cam 230 rotates from the inner base circle 225 to the braking cam lobes 232 and 233 , the motion of the braking cam lobes is transmitted to the exhaust valves 300 through the exhaust valve actuator 200 (through the rocker arm 210 and the valve bridge 400 ) and the braking piston 160 . When the cam 230 rotates over the bottom portion of the enlarged conventional cam lobe 220 and continues to rotate upward to the top portion of the enlarged conventional cam lobe 220 , the reset piston 170 makes a downward translational motion along with the valve bridge 400 , while the adjusting screw 1102 rotates clockwise along with the rocker arm 210 , and the reset distance 1312 between the adjusting screw 1102 and the reset piston 170 is reduced. When the enlarged cam lobe 220 of the cam 230 pushes the valve bridge 400 and the exhaust valves 300 downward to the lowest position (i.e., the valve lift is increased and enters into the top portion, for example, at point 220 r in FIG. 5 ), the adjusting screw 1102 pushes the reset piston 170 downward, and the reset valve is changed from the oil-feeding position to the oil-draining position, and the reset oil passage 415 is opened to discharge oil. The braking piston 160 in the valve bridge 400 of the exhaust valve actuator 200 is moved from the extended position to the retracted position. A part of the motion from the top portion of the enlarged conventional cam lobe 220 of cam 230 is lost, and the enlarged conventional valve lift profile 220 e generated by the enlarged conventional cam lobe 220 is reset and reduced to the conventional valve lift profile 220 m generated by the conventional cam lobe of the engine.
[0067] Once the cam 230 rotates over the highest position of the enlarged cam lobe 220 and moves downward from the top portion to the bottom portion of the enlarged cam lobe 220 , the rocker arm 210 rotates counterclockwise, and the adjusting screw 1102 moves upwards along with the rocker arm 210 . The valve bridge 400 also makes an upward translational motion, and the reset distance 1312 is increased. The reset piston 170 in the valve bridge 400 moves upward under oil pressure and returns to the oil-feeding position from the oil-draining position, such that the reset oil passage is closed again. The braking piston 160 in the valve bridge 400 returns to the extended position from the retracted position, and the hydraulic linkage between the braking piston 160 and the valve bridge 400 is re-established, such that the motion from the braking cam lobes 232 and 233 is transmitted to the exhaust valves 300 .
[0068] The above valve lift resetting process is completed in one braking cycle. The braking cycle repeats until the brake control mechanism 50 is turned off. At this time, the brake control mechanism 50 discharges oil (for a three-way solenoid valve 51 ) or ceases the oil supply (for a two-way solenoid valve). The valve lift reset mechanism 150 drains oil once in each engine cycle, and the oil drained is not supplemented, such that the hydraulic linkage between the braking piston 160 and the valve bridge 400 is eliminated, and the gap 234 in the valve actuation chain is formed again. Thus, the motion from the braking cam lobes 232 and 233 is skipped and will not be transmitted to the exhaust valves 300 , and the engine braking operation is turned off and the engine resumes its conventional operation state.
Fourth Embodiment
[0069] Reference is made to FIGS. 10 and 11 , which are schematic diagrams showing a valve lift reset mechanism according to a fourth embodiment of the present application when an engine brake is at the “OFF” and “ON” positions respectively. The braking actuation mechanism 100 includes a braking piston 1601 and a braking piston 1602 (referred to as braking pistons 160 ) which are slidably disposed in a piston bore 1901 and a piston bore 1902 (referred to as piston bores 190 ) respectively in the valve bridge 400 and are movable between a non-operating position (see FIG. 10 ) and an operating position (see FIG. 11 ). The non-operating position and the operating position form a gap 234 in the exhaust valve actuation chain (between the valve bridge 400 and the valves 300 ) for skipping the motion from the bottom portion of the cam 230 (including small cam lobes 232 and 233 ) during the conventional operation of the engine.
[0070] A preload spring 198 for an anti-impact mechanism is a leaf spring placed between the valve bridge 400 and the valves 300 and biases the valve bridge 400 upward against the rocker arm 210 (against the elephant foot pad 114 ). A middle of the preload spring 198 is fixed on the valve bridge 400 by a screw 179 , and two ends of the preload spring 198 are respectively located on valve spring retaining rings 3021 and 3022 fixed onto two valve stems. The braking pistons 160 are not subjected to any force of the preload spring 198 . The design of the preload spring 198 only needs to consider the rotational inertia of the valve actuation chain or no-follow, and the spring preload force does not limited to the actuation oil pressure of the braking pistons 160 . Therefore, the anti-impact mechanism of the present application can maintain the gap 234 in the valve actuation chain so as to prevent no-follow or impact in the valve actuation chain without impeding the actuation of the brake actuation mechanism 100 .
Fifth Embodiment
[0071] As shown in FIG. 12 , in a valve lift reset mechanism according to a fifth embodiment of the present application, the anti-impact mechanism, the valve lift reset mechanism 150 and the overload pressure relief mechanism are integrated together. The preload spring 198 (which is shown as the leaf spring, and can also be a coil type or other spring) of the anti-impact mechanism is placed between the rocker arm 210 and the valve bridge 400 , with one end being fixed to the rocker arm 210 by a screw 179 and the other end being pressed on a pressure relief valve ball 170 of a pressure relief valve. The preload spring 198 is used to maintain the gap 234 in the valve actuation chain so as to prevent no-follow and impact in the valve actuation chain. The preload spring 198 of the anti-impact mechanism is also a pressure relief spring for the overload pressure relief mechanism, and the pressure relief valve ball 170 of the overload relief mechanism is also a reset valve ball for the valve lift reset mechanism 150 .
[0072] When the engine braking is required, the brake control mechanism is turned on (see FIG. 3 ). The solenoid valve 51 supplies oil to the brake actuation mechanism 100 through a brake fluid network (see FIG. 12 ). Oil pressure overcomes the preload force of the spring 156 and opens the one-way valve 172 . The oil flows into the braking piston bore 190 and a hydraulic linkage is formed between the braking piston 160 and the valve bridge 400 by the engine oil. When the cam 230 rotates, the whole motion of the cam 230 , including the motion of the small braking cam lobes 232 and 233 , can be transmitted to the exhaust valves 300 through the hydraulic linkage to produce the engine braking.
[0073] When the load acting on the braking piston 160 , i.e. a braking oil pressure, exceeds a predetermined value, the oil pressure force on the pressure relief valve ball (also the reset valve ball) 170 will exceed the preload force of the pressure relief spring (also the preload spring) 198 , and pushes the pressure relief valve ball 170 upward and out of the valve seat, such that a pressure relief oil passage (also a reset oil passage) is opened to discharge oil and reduce the oil pressure, thereby ensuring that the load on the braking piston will not exceed the predetermined value.
[0074] The working process of the valve lift reset mechanism 150 according to the present embodiment is also different. When the cam 230 rotates, the reset valve ball (also the pressure relief valve ball) 170 makes a downward translational motion along with the valve bridge 400 , and the preload spring 198 fixed on the rocker arm 210 rotates with the rocker arm 210 , such that a distance between the preload spring 198 and the reset valve ball 170 is increased. When the valve bridge 400 and the exhaust valves 300 pushed downward by the enlarged cam lobe 220 of the cam 230 approach the lowest position (i.e., the valve lift approaches to the peak lift, for example at the reset point 220 r in FIG. 5 ), the preload spring 198 will leave the reset valve ball 170 , and then the reset valve ball 170 moves upward and is out of the valve seat to open the reset oil passage 415 to discharge oil. The braking piston 160 in the valve bridge 400 returns to the retracted position from the extended position, thereby eliminating the hydraulic linkage between the braking piston 160 and the valve bridge 400 , such that the enlarged main valve lift profile 220 v generated by the enlarged conventional cam lobe is reset and reduced to the conventional valve lift profile 220 m generated by the conventional engine cam lobe (see FIG. 5 ).
[0075] Once the cam 230 rotates over the highest point of the enlarged cam lobe 220 , the rocker arm 210 begins to rotate counterclockwise and the preload spring 198 moves upward along with the rocker arm 210 , and the valve bridge 400 also makes an upward translational motion, thus the distance between the valve bridge 400 and the preload spring 198 is reduced. The preload spring 198 pushes the reset valve ball 170 back to the valve seat, thereby closing the reset oil passage 415 . Oil flows into the braking piston bore 190 via the one-way valve 172 , and the braking piston 160 in the valve bridge 400 returns to the extended position from the retracted position, such that a hydraulic linkage is formed between the braking piston 160 and the valve bridge 400 , and the motion from the small braking cam lobes 232 and 233 is completely transmitted to the exhaust valves 300 . Such braking cycle is repeated until the brake control mechanism 50 is turned off (see FIG. 4 ).
Sixth Embodiment
[0076] Reference is made to FIGS. 13 and 14 , which are schematic diagrams showing a valve reset mechanism according to a sixth embodiment of the present application when an engine brake is at the “OFF” and “ON” positions respectively. During the engine braking of the present application, the motion of the braking cam is only transmitted to one exhaust valve 3001 at a side next to the rocker arm shaft 205 . The braking piston 160 of the brake actuation mechanism 100 is placed in a piston bore at a left end of the valve bridge 400 and is slidable between a non-operating position (see FIG. 13 ) and an operating position (see FIG. 14 ). The non-operating position and the operating position form a gap 2342 (see FIG. 10 ) between the braking piston 160 and the valve bridge 400 , and at the same time, a gap 234 is also required to be formed inside the valve actuation chain. The braking piston 160 is generally biased downward at the non-operating position in the valve bridge by a brake spring 177 fixed on the valve bridge 400 (see FIG. 13 ). The stroke of the braking piston 160 is limited by a snap ring 176 . The lash 132 of the braking exhaust valve 3001 (see FIG. 13 ) is controlled by a braking valve lash adjusting screw 1103 which is fastened on the rocker arm 210 by a nut 1053 . A braking elephant foot pad 1142 is provided under the adjusting screw, and acts on the braking piston 160 . The one-way valve 172 is located in an oil passage 410 in the valve bridge 400 .
[0077] The preload spring 198 of the anti-impact mechanism is placed between the rocker arm 210 and the valve bridge 400 , with an upper end abutting against the rocker arm 210 and a lower end located on a spring seat 176 on the valve bridge 400 . The spring seat 176 also acts as a stopper to limit the stroke of the reset piston 170 . The preload spring 198 is used to maintain the gap 234 in the valve actuation chain so as to prevent no-follow and impact in the valve actuation chain. Herein, the preload spring 198 of the anti-impact mechanism is also a pressure relief spring for the overload pressure relief mechanism, and the pressure relief piston 170 of the overload pressure relief mechanism is also a reset piston for the valve lift reset mechanism 150 .
[0078] When the engine braking is required, the brake control mechanism (see FIG. 3 ) is turned on. The solenoid valve 51 supplies oil to the brake actuation mechanism 100 through the brake fluid network (see FIG. 13 ). Oil flows into a high-pressure oil passage 412 through the one-way valve 172 . Oil pressure pushes the reset piston (also the pressure relief piston) 170 upward to the oil-feeding position (see FIG. 14 ) from the oil-draining position (see FIG. 13 ), thereby closing the valve lift reset oil passage 415 . At the same time, the oil pressure overcomes the force of the brake spring 177 and pushes the braking piston 160 upward to the operating position (see FIG. 14 ) from the non-operating position (see FIG. 13 ), such that a hydraulic linkage is formed between the braking piston 160 and the valve bridge 400 by the engine oil. When the cam 230 rotates, the whole motion of the cam 230 , including the motion of the small braking cam lobes 232 and 233 , can be transmitted to the exhaust valves 3001 through the hydraulic linkage, thereby producing the engine braking.
[0079] When the load acting on the braking piston 160 , that is the braking oil pressure, exceeds a predetermined value, the oil pressure force on the pressure relief piston (also the reset piston) 170 will exceed the preload force of the pressure relief spring (also the preload spring) 198 , so as to further push the pressure relief piston 170 upward (the spring seat 176 is also pushed upward) and open the pressure relief oil passage (also the reset oil passage) 415 to discharge oil and reduce pressure. In this way, the load acting on the braking piston will not exceed the predetermined value.
[0080] The working principle of the valve lift reset mechanism 150 according to the present embodiment is different. When the cam 230 rotates, the rocker arm 210 rotates clockwise and the valve bridge 400 makes a downward translation motion. A distance between the rocker arm 210 and the valve bridge 400 is increased at an end close to the rocker arm shaft 205 , for example at the position of the brake adjusting screw 1103 , however the distance between the rocker arm 210 and the valve bridge 400 is reduced at an end far away from the rocker arm shaft 205 , for example at the position of the reset adjusting screw 1102 .
[0081] When the enlarged cam lobe 220 of the cam 230 pushes the valve bridge 400 and the exhaust valves 300 downward and enters the top portion of the valve lift profile ( 220 b in FIG. 5 ), a rod with a spherical head 112 in the exhaust valve lash adjusting screw 110 moves upward to eliminate the gap 234 and close an oil supply passage 113 . The motion of the enlarged cam lobe 220 is transmitted to the two valves 300 through the rocker arm 210 , the rod with a spherical head 112 and the valve bridge 400 . At the same time, a reset distance 1312 between the reset adjusting screw 1102 and the reset piston 170 is reduced. The adjusting screw 1102 pushes the reset piston 170 downward to open the reset oil passage 415 to discharge oil. Without oil pressure, the braking piston 160 is moved downward under the action of the brake spring 177 from the operating position to the non-operating position, and the hydraulic linkage between the braking piston 160 and the valve bridge 400 is temporarily eliminated, and will be re-established when the exhaust valves 300 return to the bottom portion of the valve lift profile (i.e. 220 a in FIG. 5 , the above process can be referred to the following detailed description). Accordingly, during the process of moving downward till onto the valve seat, the braking exhaust valve 3001 is not subjected to the action of the brake actuation mechanism 100 (the braking piston 160 ), and the valve lift profile of the braking exhaust valve 3001 is reset from 220 v to the conventional valve lift profile 220 m , with the closing timing ( 220 b in FIG. 5 ) being advanced and the valve lift at the top dead point being reduced.
[0082] When the cam 230 rotates over the highest point of the enlarged cam lobe 220 , the rocker arm 210 begins to rotate counterclockwise, the reset adjusting screw 1102 moves upward along with the rocker arm 210 , and the valve bridge 400 also makes an upward translational motion. Thus, the reset distance 1312 between the reset adjusting screw 1102 and the reset piston 170 is increased. When the exhaust valves 300 moves upward into the bottom portion of the valve lift profile ( 220 a in FIG. 5 ) and is close to the valve seat, the rod with a spherical head 112 in the exhaust valve lash adjusting screw 110 (due to the oil pressure, a spring could be added if needed) moves downward, thereby generating the gap 234 and re-opening the oil supply passage 113 . Oil flows into the high-pressure oil passage 412 through the one-way valve 172 . Oil pressure pushes the reset piston 170 upward back to the oil-feeding position (see FIG. 14 ) from the oil-draining position (see FIG. 13 ), thereby closing the valve lift reset oil passage 415 . At the same time, the oil pressure overcomes the force of the brake spring 177 and pushes the braking piston 160 upward back to the operating position (see FIG. 14 ) from the non-operating position (see FIG. 13 ). The hydraulic linkage is re-established between the braking piston 160 and the valve bridge 400 by the engine oil. The whole recovery process is completed during a period between 225 b and 225 d in FIG. 5 . Therefore, the motion from the small braking cam lobes 232 and 233 can be completely transmitted to the exhaust valve 3001 . The above braking cycle is repeated until the brake control mechanism 50 is turned off (see FIG. 4 ).
[0083] The above description discloses a valve lift reset apparatus and method for the engine braking. The working principle is to change the position of the reset valve between the rocker arm and the valve bridge through the change of the distance between the rocker arm and the valve bridge, and to reset the braking valve lift in each engine braking cycle. The above various embodiments should not be regarded as limiting the scope of the present application, but rather as specific exemplifications representing the present application. Many other variations are likely to be derived from the above embodiments. For example, the engine brake can be an integrated rocker arm brake or an integrated valve bridge brake; there can be one braking piston or more braking pistons, such as dual braking pistons in the valve bridge; and during the engine braking, one exhaust valve can be opened, or more exhaust valves can be opened, such as a double-valve braking.
[0084] In addition, for the compression release type engine brake and the bleeder type engine brake, the reset positions of the exhaust valve lift are both at the top portion of the valve lift, that is, a portion above the braking valve lift.
[0085] Also, the reset valve of the valve lift reset mechanism can have different forms, including a lifting-type plunger valve or a sliding-type plunger valve both formed by a reset piston, a lifting-type ball valve or a lifting-type column valve both formed by a reset valve ball, as well as other mechanisms having functions of opening and closing the reset flow passage. These reset valves are interchangeable as needed.
[0086] In addition, the load bearing mode of the engine brake can be hydraulic (a hydraulic linkage to support the braking load) or mechanical (a mechanical linkage to support the braking load).
[0087] Also, the preload spring 198 can be installed at different positions, for example, between the braking piston and the rocker arm, or between the braking piston and the valve bridge, or between the rocker arm and the valve bridge, or between the rocker arm and the engine, or between the valve bridge and the exhaust valve, etc. The preload spring 198 can also adopt different forms, such as a leaf spring. The function of the preload spring 198 is to ensure that no-follow or impact will not occur in the exhaust valve brake system.
[0088] Therefore, the scope of the present application should not be determined by the above-described specific examples, but is defined by the claims. | A method and apparatus for resetting a valve lift for use in an engine brake. A brake piston ( 160 ), and a hydraulic fluid passage ( 214 ) are arranged within a rocker arm ( 210 ) or a valve bridge ( 400 ) of an engine. A resetting valve arranged between the rocker arm ( 210 ) and the valve bridge ( 400 ) is driven by a change in the distance between the rocker arm ( 210 ) and the valve bridge ( 400 ). When the valve lift of an engine exhaust valve ( 300 ) reaches a maximum, a reset fluid passage ( 219 ) is opened, the hydraulic pressure within the hydraulic fluid passage is released, the brake piston ( 160 ) is reversed by one interval, the motion transmission between a cam ( 230 ) and the engine exhaust valve ( 300 ) is partially disengaged, and the valve lift of the engine exhaust valve ( 300 ) is reduced. Also, during a returning process of the valve lift of the engine exhaust valve ( 300 ) after reaching the maximum position, repositioning of the reset valve is used to maintain a supply of pressure within the hydraulic fluid passage, the brake piston ( 160 ) is allowed to be positioned at an extended position, and the motion transmission between the cam ( 230 ) and the engine exhaust valve ( 300 ) is resumed. The apparatus for resetting the valve lift can be integrated within an engine exhaust valve brake, and is structurally simple, convenient to install and to adjust, thereby improving safety and reliability. | 5 |
FIELD OF INVENTION
[0001] The present invention relates generally to flexible polyurethane foam compositions that incorporate partially and/or totally exfoliated clay based nanocomposite material. The invention also relates to the foams formed from the compositions, the preparation of the foams and uses thereof.
BACKGROUND TO INVENTION
[0002] Polymeric foam materials are known for a variety of uses. For example, polymer foams are used for insulation in building, in cushioning in automotive seating and in sound damping and related applications.
[0003] An important factor in determining the use of a polymer foam material is the degree of fire retardancy of the foam. Materials such as unmodified polyurethane foams burn easily to release toxic fumes. It is therefore desirable to have polyurethane foams that resist combustion when ignited and/or which release lower amounts of toxic and/or environmentally undesirable fumes.
[0004] Presently, flame retarding agents have been used as additives to foam compositions to minimise combustion. However, flame retardants can compromise the desirable physical properties of the final foam material. Flame retardants which contain halogens or phosphorous based compounds may also be undesirable due to toxicity implications and environmental impact.
[0005] Although the use of clay as an additive to polymer materials as a flame retardant has been considered, [Polymer—Layered Silicate Nanocomposite with Conventional Flame Retardants, J. W. Gilman T. Kashiwagi, Polymer Clay Nanocomposites, Ed. T. J. Pinnavaia G. W. Beall, 2000, Wiley and references therein], the use of clay as a flame retardant in polyurethane foam materials has not been reported. Materials containing dispersed exfoliated clay particles are generally known as nanocomposites.
[0006] U.S. Pat. No. 6,518,324 describes the use of a nanoclay material in a foam composition, and in a foam made from the composition. The patent reports that the incorporation of a nanoclay material improves the thermal insulation properties and affects the cell structure, to give a fine cell foam structure. However, for a cellular polyurethane foam to be an insulating material it must have a ‘closed’ cell structure, in contrast to a flexible foam, which must have an ‘open’ cell structure. The patent suggests therefore that the foam produced thereby has a different structure to existing foam materials which do not incorporate a nanoclay. The physical properties of a foam may be closely affected by the foam cell structure and no indication is given in the patent on whether the resultant foam can simply replace existing foam materials, or if the properties of conventional foams are retained. The patent indicates that the foam produced thereby has a fine closed cell structure caused by incorporating the nanoclay. Clearly the nanoclay has an effect on the foam structure, and has achieved an effective barrier to the loss of the halogen containing foaming agent from the closed cell structure, achieving an improvement in the thermal insulation characteristics of the rigid polyurethane foam.
[0007] An important property for flexible foams for use in seating is the comfort characteristic to the user. It is desirable for this characteristic to be maintained in fire retardant foams used for seating applications.
[0008] There is a need for foam materials having good fire retardant properties which are easily made, substantially retain the physical properties of conventional foam materials, and minimise the amount of fire retarding chemical additives used in the foams.
[0009] It is an object of the present invention to obviate and/or mitigate at least one of the above mentioned problems.
[0010] It is a further object of the present invention to provide a flame retardant nanocomposite polymer foam which at least partially retains the physical properties of conventional polymer foams.
[0011] It is yet a further object of the present invention to provide a process for producing nanocomposite polyurethane foam compositions and flexible polyurethane foams formed therefrom.
SUMMARY OF INVENTION
[0012] According to a first aspect there is provided a mixture for use in forming a foamed polyurethane said mixture comprising components necessary for forming a polyurethane foamed material, clay particles and at least one coupling agent.
[0013] The components necessary for forming a foamed polyurethane generally comprise at least one polyol and/or amine, an isocyanate, a catalyst, a surfactant and water and/or a blowing agent.
[0014] According to a second aspect of the present invention there is provided a flexible foam material comprising a polyurethane composite material, wherein the polymer composite material comprises exfoliated clay particles dispersed therein and at least one coupling agent.
[0015] Desirably the mixture or composite material further comprises a char promoting agent and/or fire retardant. Suitable char promoting agents include melamine, ammonium polyphosphate, trichloropropyl phosphate (TCPP), triethyl phosphate (TEP), diethyl ethyl phosphate (DEEP) and diethyl bis(2 hydroxyethyl)amino methyl phosphonate. Suitable fire retardants include brominated phthalic anhydride based ester, dibromoneopentyl glycol, brominated polyether polyol and aluminium trihydrate or similar alternatives.
[0016] The term “polyurethane composite material” is defined herein as a polyurethane material having dispersed therein exfoliated clay particles. It is to be understood that the term exfoliated clay particles relates to clay particles which have been disrupted by suitable energy, which will be described in more detail hereinafter, to overcome the interactions between clay platelets. The exfoliated clay particles includes particles which have been partially disrupted i.e. not all interactions between particles have been overcome and/or fully exfoliated clay particles in which all interactions between clay particles have been overcome.
[0017] The term “foam material comprising a polyurethane composite material” is generally defined to mean that a foam material is formed of a polyurethane composite material.
[0018] Advantageously, such foam materials generally require little or no, or at least, less flame retarding agents due to the clay particles dispersed therein.
[0019] Although zero amount of flame retarding agent is preferred, it may be advantageous to incorporate a char promoting agent such as melamine and/or a fire retardant agent, as described above.
[0020] It has been observed by the present inventors that the incorporation of a nanoclay material into a polymer foam composition to obtain the final foam material can be difficult. In particular it can be difficult to obtain the desirable properties of the comfort characteristics found in conventional foams which do not contain nanoclay material. It is thought that this may be due to the reinforcing effects of the exfoliated clay particles on the polyurethane resin resulting in the reinforcement of the mechanical properties observed as an increased hardness of the foam. Moreover, such exfoliated clay particles may affect thin film formation during formation of the foam material. Compensation for the effects of increase in hardness accompanying the incorporation of the exfoliated clay can be achieved by adjustment of the polyurethane matrix characteristics.
[0021] Effective exfoliation of clay particles improve the gas barrier properties of the foam and enhances char formation under combustion conditions. The exfoliated clay particles appear to reduce oxygen ingress into the foam matrix and reduce volatile product egress from the foam. However incorporation of exfoliated clay particles can result in a high viscosity of the composition, particularly the low shear viscosity, resulting in compromised rapid mixing of the composition. Rapid and even mixing of a foam composition prior to foam formation can be important to ensure a homogeneous mixture of reactants is achieved before substantial foaming starts; this ensures as much as possible that a homogeneous foam material is formed with an even cellular distribution and a uniform dispersion of the exfoliated clay platelets.
[0022] The use of a coupling agent advantageously provides a polyurethane foam composition having a viscosity desirable for manipulating the composition prior to foam formation, while maintaining at least some dispersed clay particles therein.
[0023] Clay materials are natural or artificial minerals comprising particles in the form of platelets, and include smectite, vermiculite and halloysite clays.
[0024] The smectite type can be further categorised into montmorillonite, saponite, beidellite, nontrite, and hectorite.
[0025] An artificial clay material is for example laponite.
[0026] A preferred clay material for use in the present invention is a montmorillonite clay which is an aluminosilicate clay of formula:
M + y (Al 2-y Mg y )(Si 4 )O 10 (OH) 2 n H 2 O
[0027] Suitable montorillonite clays for use in the present invention may be obtained commercially under the trade name Cloisite® e.g. Cloisite® 6A, Cloisite® 15A, Cloisite® 20A, Cloisite® 10A, Cloisite® 25A, Cloisite® 30B and Cloisite® Na + . These are termed organically modified clay materials but may or may not incorporate an organic modifier.
[0028] Typically the amount of incorporated into the foam composition is generally between above 0 to about 20% by weight of the total foam composition weight.
[0029] The amount of clay may be from about 0.1% to about 15% by weight of the total foam composition weight.
[0030] Preferably the amount of incorporated clay is from about 1% to about 10% by weight of the total foam composition weight, e.g. 8% by weight of the total foam composition weight.
[0031] The nanoclay materials comprise platelet particles.
[0032] Typically the exfoliated nanoclay platelets have a thickness of around 1 nm and a size in the planar direction of around 0.01 μm to 100 μm.
[0033] Each individual platelet particle may have a length/thickness ratio of around 200-1000.
[0034] The ideal dispersion would be completely exfoliated clay platelets but enhancement over existing foams may be achieved with partially exfoliated clay particles.
[0035] The platelets generally aggregate together with the planar surfaces adjacent, into stack structures. The space between the platelets in these stacks is generally known as a gallery. The separation of the platelets across the gallery is generally of the order of 3-5 Å. In organically modified clay particles the gallery separation has been increased to a value of the order of 18 Å.
[0036] In a preferment, the clay minerals have undergone a cation exchange with at least one cationic organic species.
[0037] For example, sodium ions on the surface of the clay particles may be exchanged with the cationic organic species.
[0038] The cationic organic species may comprise for example a quarternary ammonium ion species or an onium species.
[0039] Examples of suitable quaternary ammonium ion species include alkyl ammonium ions, e.g. dimethyl dihydrogenatedtallow ammonium, which has the following formula:
[0040] dimethyl benzylhydrogenatedtallow ammonium, which has the following formula:
[0041] dimethyl hydrogenatedtallow (2-ethylhexyl)ammonium, which has the following formula:
[0042] and methyl bis 2-hydroxylethyl ammonium, which has the following formula:
[0043] where, in each of the above formulae, T=tallow and HT=hydrogenatedtallow having a chain length with an approximate content of 65% C 18 , 30% C 16 and 5% C 14 .
[0044] Without wishing to be bound by any particular theory, the inventors believe that the cationic organic species modify the surface of the clay particles. The inventors believe that the organic modifier changes the hydrophobicity of the platelet surface thereby enabling better dispersibility of the platelet particles within a hydrophobic polymer material.
[0045] Accordingly, the use of a cationic organic species may enhance the compatibility of the clay particles with the polymer material.
[0046] Furthermore, the gallery space separation of clay platelets may be increased through treatment with a cationic organic species to allow the polymer material to enter the gallery space. This may advantageously result in an increased dispersibility of the platelets within the polymer material.
[0047] Further increases in gallery spacing and movement of the platelets away from a stack structure results in further dispersion of the platelet particles within the polymer material and this is termed herein as exfoliation.
[0048] Organic cationic species are described in U.S. Pat. Nos. 5,530,052 and 5,773,502 which are incorporated herein by reference.
[0049] The inventors of the present invention have also found advantageous use of a so-called coupling agent with the clay materials.
[0050] Coupling agents are known and are described in S. J. Monte and G. Sugerman, Kenrich Petrochemicals Inc and A. Damusis and P. Patel Polymer Institute University of Detroit, “Application of Titinate Coupling Agents in Mineral and Glass Fibre Filled RIM Urethane Systems,” SPI Urethane Div, 26 th Annual Conference (November 1981). Polyurethanes with inorganic fillers, Nippon Soda Co Ltd, Jpn Kokai Tokkyo Koho JP 60, 71625 28 Sep. 1983. all of which are incorporated herein by reference. The coupling agents are described as reducing the viscosity of various polymer compositions.
[0051] Without wishing to be bound by any particular theory, it is proposed that the coupling agent is able to add to positive sites on the edges of the clay particles which results in blocking the formation of viscosity enhancing ‘house of cards’ platelet structures.
[0052] Advantageous coupling agents for use in the present invention comprise neoalkoxy titanate or neoalkoxy zirconate agents.
[0053] Particularly advantageous is the neoalkoxy titanate agent, neopentyl(diallyl)oxy tri(dioctyl)phosphate titanate which has the formula (I) indicated below, and is known by the tradename LICA® 12.
[0054] The coupling agent may be incorporated into a foamed polyurethane composite material at an amount of above 0 to about 10% by weight of the total foam composition weight.
[0055] An amount of coupling agent of from about 0.001% to about 6% preferably 0.005 to 2% of the weight of the clay in the total foam composition may be used.
[0056] Typically, polyurethane foams may be made through the use of external addition of a gas in situ on generation of the polyurethane or a combination of these two mechanisms.
[0057] The foam-forming gas or a gas precursor material is generally known as a blowing agent.
[0058] Preferred foam compositions are those in which the gas for forming the foam is generated in situ. For example the gas may be generated through chemical reaction of a constituent of the foam forming composition.
[0059] Preferred polyurethane formulations of this type are polyurethanes that generate carbon dioxide gas on mixing the starting materials required for forming the polymer.
[0060] The term “polyurethane foam” used herein refers to an open-celled flexible product obtained by reacting a polyisocyanate with isocyanate-reactive hydrogen containing compounds and a foaming agent.
[0061] In particular, the foaming agent or the blowing agent generally used for a polyurethane foam is carbon dioxide, which is generated by the reaction of water with isocyanate groups to give urea linkages and a polyurea-urethane foam.
[0062] The isocyanate reactive compounds may be chosen from polyols, aminoalcohols and/or polyamines.
[0063] Examples of polyols include reaction products of alkylene oxide, for example ethylene oxide and propylene oxide; polyesters obtained by the condensation of glycols and higher functionality polyols with polycarboxylic acids; hydroxyl terminated polythioethers; polyamides; polyesteramides; polycarbonates; polyacetals; and polysiloxanes. Other isocyanate-reactive compounds include ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, butane diol, glycerol, trimethylolpropane, ethylene diamine, ethanolamine, diethanolamine, triethanolamine, pentaerythritol, sorbitol, sucrose, polyamines such as ethylene diamine, tolylene diamine, diaminodiphenylmethane and polymethylene polyphenylene polyamines, and aminoalcohols such as ethanolamine and diethanolamine and mixtures thereof.
[0064] A flexible polyurethane foam may be prepared by reacting a polyisocyanate with a relatively high molecular weight isocyanate-reactive polymer, e.g. a polyester or polyether polyol, in the presence of a blowing agent and typically including additives such as catalysts, surfactants, fire retardants, stabilisers and/or antioxidants.
[0065] Suitable surfactants would include polyoxyalkylene polysiloxane copolymers or related materials.
[0066] The flexible foam may be prepared according to the one-shot process where the urethane and urea reactions occur simultaneously or using the quasi or semi prepolymer or prepolymer processes. In the latter the polyol is first reacted with an excess of isocyanate and the resulting isocyanate prepolymer reacted in a second step with water and the other additives. [The Polyurethane Handbook, D. Randall and S. Lee, John Wliey & Sons, 2002.]
[0067] Flexible foams prepared by the reactive mixing of an isocyanate with a polyol and/or amine may be used to produce moulded foams or generate slabstock foams for use for example as cushioning material in furniture and automotive seating, in mattresses, as carpet backing, foam in diapers, packaging foam, or sound insulation foam.
[0068] Polyisocyanates for use in the present invention include any of those known in the art for preparing polyurethanes. For example, aliphatic, cycloaliphatic, aryl-aliphatic and aromatic polyisocyanates.
[0069] Examples of aromatic polyisocyanates include toluene diisocyanate e.g. toluene 2,4-diisocyanate and toluene 2,6-diisocyanate and mixtures thereof; diphenylmethane diisocyanate e.g. the 2,4′-, 2,2′- and 4,4′-isomers, polymeric isocyanates and isocyanurates, thereof and mixtures thereof, including oligomers thereof.
[0070] The present invention in a third aspect provides a method of making a flexible foam material comprising:
[0071] providing a mixture comprising components required for forming a foamed polyurethane, clay particles for dispersion within said foamed polyurethane and at least one coupling agent; and forming the mixture into a flexible foam material.
[0072] The mixture is as previously defined above and may further comprise additional preferred components as described hereinbefore.
[0073] The mixture may be provided according to any suitable technique. The inventors have found that the fire retardant properties of the foam composite material benefit from incorporation of clay material which has been subjected to high shear mixing with at least one of the components required for forming the foamed polyurethane e.g. the polyol.
[0074] It is suggested that this observation is linked to the degree of dispersion or exfoliation of the clay particles within the polymer composition.
[0075] High shear mixing may be achieved with a mechanical mixer such as an ultra turrax mixer. However the inventors observed that mechanical mixing alone may not optimise the dispersion of the clay particles into an exfoliated state.
[0076] Advantageously, the use of ultrasound in the presence or absence of mechanical stirring, provides an effective means for dispersion of the clay particles within the foam composition into an exfoliated state.
[0077] Preferably, the ultrasound is applied as high frequency ultrasound. The frequency range will typically be in the range 1 kHz to 10 MHz but will preferably be in the kilo hertz frequency range.
[0078] The ultrasound may be applied simultaneously with mechanical mixing.
[0079] The ultrasound may be applied for a period of time sufficient to achieve desired exfoliation. Depending on the type of process being adopted this could be between for example 0.1 seconds to 2 hours.
[0080] Typically in a small batch process the ultrasound is applied for a period of time of from 10 seconds to 30 minutes.
[0081] Preferably the ultrasound is applied for a period of time of from 30 seconds to 20 minutes, e.g. 15 minutes.
[0082] Alternatively, microwaves, infrared radiation or other electromagnetic radiation may be applied to the nanocomposite formulation to achieve dispersion and exfoliation of the clay particles.
[0083] Without wishing to be bound by any particular theory, the effective dispersion of the clay particles in the composition is believed to be associated with the ability to couple energy selectively into molecular species which are capable of supplying the necessary energy to overcome the interactions between the clay platelets. In the case of ultrasound, the frequency chosen is preferably that which is associated with binding of water molecules to inorganic species and the hypothesis is that these molecules are selectively excited by the ultrasound which results in exfoliation of the clay particles. Similar mechanisms for the provision of energy to the galleries may be used with other selective forms of irradiation.
[0084] According to a fourth aspect of the present invention there is provided a process for preparing a pre-polyurethane composition comprising the steps of:
[0085] providing a polyol,
[0086] introducing a clay material into the polyol and applying ultrasound to form a dispersed mixture, and introducing water, a polyisocyanate and optionally at least one coupling agent into said dispersed mixture to form a final prefoamed polyurethane composition and allowing the prefoamed polyurethane composition to polymerise and form a polyurethane foam nanocomposite material.
[0087] For example, following foam formation, the foam is allowed to cure to form a final polyurethane foam nanocomposite material.
[0088] The term “prefoamed-polyurethane” as used herein relates to a composition which is capable of forming a polyurethane polymer and/or a polyurethane polymer foam upon polymerisation of the prefoamed-polyurethane.
[0089] The water maybe added before, at the same time, or after the introduction of the polyisocyanate.
[0090] The resultant combination of components may be mechanically mixed prior to foam formation.
[0091] Prior to forming the foam nanocomposite material, the composition is usually introduced into a mould to contain the composition during foam formation, or allowed to form a free foaming slab.
[0092] At least one of the above mixing steps may be carried out simultaneously with the introduction of the composition into the mould or into a free foaming slab form.
[0093] Typically, the composition is introduced into the mould or slab forming structure by means of a reaction injection moulding device.
[0094] Preferably a coupling agent as defined hereinbefore is introduced during the preparation process.
[0095] Preferably the coupling agent is provided in the polyol containing mixture.
[0096] The composition may additionally contain other additives, such as catalysts, surfactants, flame retarding agents, stabilisers, colourants and antioxidants.
[0097] Typically, these other additives are provided in the polyol containing mixture.
[0098] Preferably, the mixture to which the ultrasound is applied is stirred and cooled during the application of the ultrasound.
[0099] The clay particles may comprise any of the clay materials described herein above.
[0100] Preferably the polyisocyanate is based on methylene diphenyl diisocyanate or toluene diisocyanate.
[0101] As an embodiment of the fourth aspect there is provided a means for preparing a prefoaming-polyurethane composition.
[0102] The means is particularly advantageous for preparing the prefoaming-polyurethane composition immediately prior to its introduction into a mould or reaction injection moulding device.
[0103] The means generally comprises a first chamber or region (A) into which is introduced a polyol and clay particles, and optionally a coupling agent and/or other additives such as a char promoting agent;
[0104] ultrasound, and optionally mechanical stirring, is applied to the mixture in chamber or region (A) to disperse the clay particles;
[0105] the resultant mixture may then optionally be moved into a second chamber or region and water and an isocyanate added in an appropriate order, with optional mechanical mixing to form the prefoaming-polyurethane composition.
[0106] Alternatively, the mixing of the constituents may be achieved by use of a mixing head in which all reactants are mixed simultaneously and ultrasound or other suitable dispersing energy applied.
[0107] The ultrasound is advantageously delivered by means of an ultrasound generating probe.
[0108] According to a fifth aspect of the present invention there is provided a polyurethane foam material obtainable by the process according to the fourth aspect.
[0109] According to a sixth aspect of the present invention there is provided use of a clay material as a fire retardant in a polyurethane nanoclay foam composite or foam nanocomposite material.
DETAILED DESCRIPTION OF THE INVENTION
[0110] Embodiments of the present invention will now be described by way of example only, and with reference to FIG. 1 which shows a graph of the results of viscosity measurements at different shear rates for a dispersion of Cloisite® 30B in a particular polyol Daltocel [F436], Huntsman Chemical, with different amounts of LICA®.
[0000] General Experimental Details
[0111] A study on the exfoliation of the nanoclay particles in the polyol component was undertaken. Ultrasound and active stirring of the liquid polyol were found to achieve good exfoliation of the dispersion of clay particles by monitoring the rheology of the dispersion. The quality of the dispersion was indicated by the extent to which the viscosity of the medium was enhanced.
[0112] The edge to face interactions between the exfoliated platelets lead to an enhancement of the low shear viscosity.
[0113] The viscosity of the particular polyol was increased from a value of about 1 Pas to a value in excess of 100 Pas. Whilst the enhancement in viscosity indicated an exfoliated clay state, it produces a problem in relation to achieving effective rapid mixing with the isocyanate prior to the foaming process. It was therefore desirable to decrease the viscosity of the polyol while retaining an exfoliated state of the clay platelets. This was achieved by the addition of the coupling agent LICA®. It is suggested that the LICA® selectively adds to the positive sites on the edges of the clay particles and blocks the formation of the ‘house of cards’, three dimensional interacting structure associated with the viscosity increase.
[0114] It appears that the use of LICA® results in exfoliated clay particles which tend to be aligned face to face rather than edge to face.
[0115] The viscosity of the resultant mixture was reduced by the addition of LICA® to about 10 Pas which is sufficiently low for effective mixing with the isocyanate. The results of viscosity measurements at different shear rates for a dispersion of Cloisite® 30B in polyol with different amounts of LICA® is shown as a graph in FIG. 1 , in which the concentration of Lica is expressed as a percentage (%) of the weight of Cloisite® 30B.
[0000] Small Scale Production of Nanocomposite Polyurethane Foam.
[0116] A small-scale duplicate of a large scale method for producing the polyurethane formulations was developed.
[0117] Moulds were constructed having internal dimensions of 130 mm×130 mm×40 mm.
[0118] The formulations used were typical of those used for the production of car seats and are based on methylene diphenyl diisocyanate (MDI). A toluene diisocyanate based system is an alternative, and sometimes preferable, but is more toxic than MDI.
[0119] The aim was to form a self-creaming foam which had the desired skin and foam cell structure which closely matched that obtained in large scale production.
[0120] To compensate for the adiabatic heating that occurs during large scale production, the cure of the samples was carried out in an oven at 40° C.
[0121] From the study it was apparent that incorporation of the clay into the formulations has a dramatic effect on the foaming process. This appeared to be due to the effects of the surface activity of the clay particles and the ability to modify the diffusion of the gas that forms the foam. A matrix of experiments was undertaken in which the conditions used in the mixing, the amounts, times of addition of the catalysts, and amounts and types of the surfactants were systematically varied.
[0122] Foams were created which had a very similar cell structure to those formed without incorporation of partially exfoliated clays. However, the foams with the partially exfoliated clays were harder than the typical car seat foams, and further optimization of the isocyanate to polyol ratio and blending of the materials was necessary to achieve a foam of equivalent flexibility to that in a foam that contained no partially exfoliated clays.
[0123] Formulations were produced which allowed the creation of foams with clay levels above 0 to 10% parts by weight of the total composition weight whilst still retaining the intrinsic foam and mechanical properties of conventional foams.
[0124] The foams produced in the small scale method had essentially the same mechanical properties as those of the commercially produced car seat supplied and yet partially exfoliated clay was incorporated to levels shown in Table 1.
[0125] The compressibility and density of the foams were used as guide criteria for optimization of the produced foams. In order to produce slightly softer, more flexible foams than those produced using the initial formulation, an alternative polyol was used or the ratio of the polyol to the isocynate altered. By changing the molar mass and functionality of the polyol it was possible to change the glass transition temperature of the foam material. Furthermore, changing the ratio of the isocyanate to polyol can vary the modulus. These criteria enabled a material to be produced with essentially the same mechanical characteristics of those for a car seat foam.
[0126] In a large scale manufacture, the foam formulations would generally be reaction injection moulded hence the requirement to maintain a viscosity which allows reaction injection moulding to be achieved. High viscosities of formulations prevent effective reaction injection moulding to be used.
[0127] Although the small scale study did not use an reaction injection moulding apparatus, a system was used which had a propeller mixture to ensure that the mixture was continuously moved through the volume being subjected to irradiation with ultrasound.
[0128] The obtained foams were examined by professional foam makers who indicated that the foams were very similar to those produced on a large scale.
[0000] Flammability Testing
[0129] Pieces of the foam were cut to approximately 13 mm×13 mm and 100 mm long. The pieces were placed on an open wire gauze and held with the longitudinal axis horizontal. The test apparatus was housed in an enclosed laboratory hood free of induced or forced draft during the test procedure. The enclosed laboratory hood was fitted with a heat resistant glass window for observing the test and an exhaust fan for removing the products of combustion after completion of the test.
[0130] A laboratory burner with a 20 mm high blue flame was used as the ignition source. The burner was positioned such that the central axis of the burner tube was in the same vertical plane as the longitudinal bottom edge of the piece of foam and inclined at 45 degrees to the horizontal. The flame was allowed to impinge on the test piece of foam for 20 seconds without changing the flame position, and then withdrawn so that there was no effect on the test piece after 20 seconds.
[0131] The following data were recorded: 1) test piece weight; 2) burn time; 3) burn distance; and 4) test piece residue weight.
[0132] The test is based on a fire-test-response test method covering a small scale laboratory screening procedure for comparing the relative linear rate of burning or extent and time of burning of plastics in the form of test pieces held in a horizontal position.
[0133] The test showed that conventional car seat foam material burnt very rapidly under the conditions and the foam material melted into the flame zone and was rapidly consumed. The degradation of the material was characterised by a highly mobile melt and bubbling as volatiles were released. The flame front was immediately behind the degradation zone with very rapid and near complete degradation to volatile species, with little char formation. The degradation products dripped through the gauze.
[0134] In comparison, the incorporation of 8 parts by weight of Cloisite® 30B nanoclay into a foam significantly decreased the rate at which flame propagation occurred. In this case the melt state was less mobile and dripping did not occur. The flame front lagged behind the degradation zone which is indicative of a slower volatile release profile, and more char was formed.
[0135] It was found that a formulation with 8 parts by weight of nanoclay and 30 parts by weight of melamine, which is a fire retardant, gave a foam which was almost self extinguishing. Other formulations were investigated which contained nanoclay in combination with other fire retardants such as tri-phenyl phosphate, Reofos NTP and Reofos 50. The foam materials of these formulations were found to have flammability characteristics not significantly better than a foam containing only nanoclay.
[0136] The flammability testing demonstrated that effective incorporation of a nanoclay into a foam formulation to produce a foam resulted in a significant improvement of the fire retardant characteristic of the foam compared to foam which did not include nanoclay.
[0137] Polyurethane foam incorporating exfoliated nanoclay based on other isocyanates, such as toluene diisocyanate, are anticipated to also exhibit enhanced fire retardant properties similar to those demonstrated with MDI.
[0000] Detailed Experimental Examples
[0138] A comparative polyurethane foam was prepared according to the following procedure:
[0139] The formulation contained 60.0 parts Suprasec 2528, a polymeric methane diphenyl diisocyanate available from Huntsman Chemicals; 100 parts Daltocel F428 (Huntsman Chemicals); 0.70 parts Dabco BL11, a reagent containing 70% Bis(dimethylaminoethyl)ether and 30% dipropylene glycol; 0.04 parts Dabco 33LV both catalysts available from Air Products; 0.58 parts Dabco DC5169 a silicon stabilizer surfactant from Air Products; 0.52 parts B-4113 a surfactant (available for Goldsmidt Chemical Corporation); 8.0 parts Cloisite® 30B (available from Southern Clay Products); 0.16 parts LICA® 12 a coupling agent (available from Kenrich Petrochemicals Inc.); 3.6 parts water as blowing agent; all parts are by weight of the total mixture. For the foam without nanoclay, the polyol, catalysts, surfactants, water were mixed in a container, followed by addition of the MDI. The mixture was vigorously stirred and poured into a mould.
[0140] A polyurethane foam containing 8.0 parts by weight of the monoclay Cloisite® 30B was prepared according to the following procedure:
[0141] A container was prepared by washing with a 3.0% solution of LICA® 12 in xylene. Into the dry container was added the polyol, catalysts, surfactants and coupling agents as indicated for the comparative polyurethane foam above, and the solution mixed. The nanoclay was added and the mixture sonicated for 15 minutes using a Cole Palmer Ultrasonic Processor with ¼ inch tapered probe and operating with 40% attenuation for a period of 15 minutes, the dispersion being stirred and cooled during the sonicating process. After sonication 3.6 parts water was added to the dispersion and the dispersion stirred vigorously for 3 minutes. 60 parts Suprasec 2528 was added to the dispersion and the mixture stirred vigorously for 10 seconds before being poured into a mould.
[0142] Further formulations were prepared as listed in Table 1.
[0143] From the prepared foam samples, a selection were tested for combustion and the results are listed in Table 2.
[0144] A further selection of prepared foam samples were tested for compressibility and the results are listed in Table 3.
[0145] These data indicate that incorporation of a nanoclay material into a foam composition can result in a significant improvement of the fire retardant characteristic of the foam compared to foam which does not include nanoclay, while retaining the desirable mechanical properties of the foam material
[0146] Sample Formulation
Cloisite Lica Sample Poly- Polyol 33LV BL11 B4113 DC5169 Water Diisocyanate 30b 12 Flame % Flame Identity ol* pbw pbw pbw pbw pbw pbw Diisocyanate** pbw pbw pbw Retardant retardant 5 428 100.00 0.40 0.043 0.585 0.500 3.60 2528 60.00 4.00 None 6 428 100.00 0.40 0.043 0.585 1.250 3.60 2528 60.00 4.00 None 7 428 100.00 0.40 0.043 0.585 0.000 3.60 2528 60.00 4.00 None 8 428 100.00 0.40 0.043 0.585 0.000 3.00 2528 60.00 4.00 None 9 428 100.00 0.40 0.043 0.585 0.000 3.00 2528 60.00 4.00 None 10 428 100.00 0.40 0.043 0.585 0.125 3.00 2528 60.00 5.00 None 11 436 100.00 0.40 0.043 0.585 0.125 3.50 2528 60.00 4.00 None 12 436 100.00 0.40 0.043 0.585 0.125 4.00 2528 60.00 4.00 None 13 436 100.00 0.41 0.042 0.667 0.125 4.00 2528 60.00 5.00 None 14 436 100.00 0.19 0.042 0.580 0.126 3.60 2528 60.00 4.00 None 15 436 100.00 0.19 0.042 0.580 0.126 3.60 2528 60.00 1.00 None 16 436 100.00 0.19 0.042 0.580 0.126 3.60 2528 60.00 2.00 None 17 436 100.00 0.19 0.042 0.580 0.126 3.60 2528 60.00 3.00 None 18 436 100.00 0.19 0.042 0.580 0.126 3.60 2528 60.00 6.00 None 19 436 100.00 0.19 0.040 0.580 0.124 6.00 2528 60.00 6.00 None 20 436 100.00 0.80 0.040 0.580 0.125 3.60 2528 60.00 6.00 None 21 436 100.00 0.80 0.040 0.580 2.000 3.60 2528 60.00 6.00 None 22 436 100.00 0.40 0.042 0.580 0.000 2.80 2528 60.00 6.00 None 23 436 100.00 0.40 0.042 0.580 0.000 2.80 2528 50.00 6.00 None 24 436 100.00 0.36 0.042 0.580 0.000 2.80 2528 50.00 6.00 None 25 436 100.00 0.36 0.042 0.580 0.000 3.20 2528 50.00 6.00 None 26 436 100.00 0.36 0.042 0.580 0.000 3.20 2528 50.00 6.00 None 27 436 100.00 0.26 0.042 0.580 0.060 3.60 2528 60.00 6.00 None 28 436 100.00 0.22 0.042 0.580 0.060 3.60 2528 60.00 6.00 None 29 436 100.00 0.32 0.042 0.583 0.067 3.60 2528 60.00 6.00 None 30 436 100.00 0.30 0.042 0.583 0.067 3.60 2528 60.00 5.00 None 30 436 100.00 0.30 0.042 0.580 0.060 3.60 2528 60.00 6.00 None 31 436 100.00 0.19 0.042 0.580 0.127 3.60 2528 60.00 4.00 None 32 436 100.00 0.30 0.042 0.580 0.300 3.60 2528 60.00 5.00 None 33 436 100.00 0.30 0.042 0.580 0.300 3.60 2528 40.00 5.00 None 34 436 100.00 0.30 0.042 0.580 0.300 3.60 2528 50.00 5.00 None 35 436 100.00 0.30 0.042 0.580 0.350 3.60 2528 60.00 6.00 None 36 436 100.00 0.32 0.042 0.580 0.383 3.60 2528 60.00 6.00 None 37 436 100.00 0.30 0.042 0.580 0.317 3.60 2528 60.00 6.00 None 40 436 100.00 0.30 0.042 0.580 0.350 3.60 2528 60.00 6.00 0.000 None 41 436 100.00 0.30 0.042 0.580 0.350 3.60 2528 60.00 6.00 0.033 None 42 436 100.00 0.30 0.042 0.580 0.350 3.60 2528 60.00 6.00 0.050 None 43 436 100.00 0.30 0.042 0.580 0.350 3.60 2528 60.00 6.00 0.067 None 44 436 100.00 0.30 0.042 0.580 0.350 3.60 2528 60.00 6.00 0.083 None 45 436 100.00 0.30 0.042 0.580 0.350 3.60 2528 60.00 6.00 0.133 None 46 436 100.00 0.19 0.042 0.580 0.127 3.60 2528 60.00 6.00 None 47 436 100.00 0.25 0.042 0.580 0.217 3.60 2528 60.00 6.00 None 48 436 100.00 0.19 0.042 0.580 0.137 3.60 2528 60.00 6.00 None 49 436 100.00 0.30 0.042 0.580 0.135 3.60 2528 60.00 6.00 None 50 436 100.00 0.30 0.042 0.580 0.500 3.60 2528 60.00 6.00 None 51 436 100.00 0.40 0.042 0.580 0.500 0.00 2528 60.00 6.00 None 52 436 100.00 0.40 0.042 0.580 0.500 3.60 2528 60.00 6.00 None 53 436 100.00 0.47 0.042 0.580 0.533 3.60 2528 60.00 8.00 None 54 436 100.00 0.53 0.042 0.580 0.533 3.60 2528 60.00 8.00 None 55 436 100.00 0.57 0.042 0.580 0.800 3.60 2528 60.00 8.00 None 56 436 100.00 0.70 0.042 0.580 0.567 3.60 2528 60.00 8.00 None 57 436 100.00 0.70 0.040 0.580 0.560 3.60 2528 60.00 8.00 None 58 436 100.00 0.70 0.042 0.580 0.567 3.60 2528 60.00 8.00 None 59 436 100.00 0.70 0.040 0.580 0.560 3.60 2528 60.00 8.00 0.160 Melamine 2.81 60 436 100.00 0.70 0.040 0.580 0.560 3.60 2528 60.00 8.00 0.160 Melamine 5.47 61 436 100.00 0.70 0.040 0.580 0.560 3.60 2528 60.00 8.00 0.160 Melamine 2.81 62 436 100.00 0.70 0.040 0.580 0.560 3.60 2528 60.00 8.00 0.160 Melamine 7.98 63 436 100.00 0.70 0.040 0.580 0.560 3.60 2528 60.00 8.00 0.160 None 64 436 100.00 0.70 0.040 0.580 0.560 3.60 2528 60.00 8.00 0.160 None 65 436 100.00 0.70 0.040 0.580 0.560 3.60 2528 60.00 8.00 0.160 None 66 436 100.00 0.70 0.040 0.580 0.560 3.60 2528 60.00 8.00 0.160 None 67 436 100.00 0.70 0.040 0.580 0.560 3.60 2528 60.00 8.00 0.160 None 68 436 100.00 0.70 0.040 0.580 0.560 3.60 2528 60.00 8.00 0.160 None 69 436 100.00 0.70 0.040 0.580 0.560 3.60 2528 60.00 8.00 0.160 Melamine 10.37 70 436 100.00 0.70 0.040 0.580 0.560 3.60 2528 60.00 0.00 0.000 None 71 436 100.00 0.70 0.040 0.580 0.560 3.60 2528 60.00 2.00 0.040 None 72 436 100.00 0.70 0.040 0.580 0.560 3.60 2528 60.00 4.00 0.080 None 73 436 100.00 0.70 0.040 0.580 0.560 3.60 2528 60.00 8.00 0.160 None 74 436 100.00 0.70 0.040 0.580 0.560 3.60 2528 60.00 10.00 0.200 None 75 436 100.00 0.70 0.040 0.580 0.560 3.60 2528 60.00 8.00 0.160 None 76 436 100.00 0.70 0.040 0.580 0.560 3.60 2528 60.00 8.00 0.160 None 77 436 100.00 0.70 0.040 0.580 0.560 3.60 2528 60.00 8.00 0.200 None 78 436 100.00 0.84 0.040 0.580 0.560 3.60 2528 60.00 8.00 0.240 None 81 436 100.00 0.70 0.040 0.580 0.560 3.60 2528 60.00 2.00 0.040 None 82 436 100.00 0.70 0.040 0.580 0.560 3.60 2528 60.00 3.00 0.060 None 83 436 100.00 0.70 0.040 0.580 0.560 3.60 2528 60.00 4.00 0.080 None 84 436 100.00 0.70 0.040 0.580 0.560 3.60 2528 60.00 5.00 0.140 None 85 436 100.00 0.80 0.040 0.580 0.560 3.60 2528 60.00 6.00 0.140 None 86 436 100.00 0.84 0.040 0.620 0.560 3.60 2528 60.00 8.00 0.160 None 0.00 87 436 100.00 0.80 0.040 0.580 0.560 3.60 2528 60.00 8.00 0.160 None 0.00 88 436 100.00 0.80 0.040 0.580 0.560 3.60 2528 60.00 6.00 0.160 None 0.00 89 436 100.00 0.80 0.040 0.580 0.560 3.60 2528 60.00 8.00 0.160 None 0.00 90 436 100.00 0.80 0.040 0.580 0.560 3.60 2528 60.00 0.00 0.140 Triphenyl phosphate 2.37 91 436 100.00 0.80 0.040 0.580 0.560 3.60 2528 60.00 0.00 0.140 Triphenyl phosphate 4.62 92 436 100.00 0.80 0.040 0.580 0.560 3.60 2528 60.00 0.00 0.140 Triphenyl phosphate 6.78 93 436 100.00 0.80 0.040 0.580 0.560 3.60 2528 60.00 6.00 0.140 Triphenyl phosphate 6.56 94 436 100.00 0.80 0.040 0.580 0.560 3.60 2528 60.00 6.00 0.140 Triphenyl phosphate 10.47 95 436 100.00 0.80 0.040 0.580 0.560 3.60 2528 60.00 9.00 0.140 Triphenyl phosphate 10.31 100 428 100.00 0.70 0.040 0.580 0.560 3.60 2528 60.00 0.00 0.000 None 0.00 101 428 100.00 0.70 0.040 0.580 0.560 3.60 2528 60.00 2.00 0.040 None 0.00 102 428 100.00 0.80 0.040 0.580 0.560 3.60 2528 60.00 8.00 0.200 None 0.00 103 428 100.00 0.80 0.040 0.580 0.560 3.60 2528 60.00 8.00 0.200 None 0.00 104 428 100.00 0.70 0.040 0.580 0.560 3.60 2528 60.00 6.00 0.160 None 0.00 105 428 100.00 0.70 0.040 0.580 0.560 3.60 2528 60.00 6.00 0.160 None 0.00 106 428 100.00 0.70 0.040 0.580 0.560 3.60 2528 60.00 0.00 0.000 Reofos NTP 5.72 107 428 100.00 0.70 0.040 0.580 0.560 3.60 2528 60.00 2.00 0.040 Reofos NTP 5.65 108 428 100.00 0.70 0.040 0.580 0.560 3.60 2528 60.00 4.00 0.080 Reofos NTP 5.59 109 428 100.00 0.80 0.040 0.580 0.560 3.60 2528 60.00 6.00 0.160 Reofos NTP 5.52 110 428 100.00 0.90 0.040 0.580 0.560 3.60 2528 60.00 8.00 0.200 Reofos NTP 5.46 111 428 100.00 0.80 0.040 0.580 0.560 3.60 2528 60.00 6.00 0.160 Reofos NTP 5.52 112 428 100.00 0.80 0.040 0.580 0.560 3.60 2528 60.00 6.00 0.160 Reofos NTP 5.52 124 428 100.00 0.70 0.040 0.580 0.560 3.60 2528 60.00 8.00 0.160 None 0.00 125 428 100.00 0.70 0.040 0.580 0.560 3.60 2528 60.00 8.00 0.160 Melamine 14.78 126 428 100.00 0.70 0.040 0.580 0.560 3.60 2528 60.00 0.00 0.000 None 0.00 127 428 100.00 0.70 0.040 0.580 0.560 3.60 2528 60.00 8.00 0.160 Melamine 14.78 128 428 100.00 0.70 0.040 0.580 0.560 3.60 2528 60.00 8.00 0.160 Melamine 14.78 129 428 100.00 0.70 0.040 0.580 0.560 3.60 2528 60.00 10.00 0.200 Melamine 14.64 130 428 100.00 0.70 0.040 0.580 0.560 3.60 2528 60.00 10.00 0.200 Melamine 14.64 131 428 100.00 0.70 0.040 0.580 0.560 3.60 2528 60.00 0.00 0.000 Melamine 10.82 132 428 100.00 0.70 0.040 0.580 0.560 3.60 2528 60.00 8.00 0.160 Melamine 14.78 133 428 100.00 0.70 0.040 0.580 0.560 3.60 2528 60.00 8.00 0.160 Melamine 12.19 134 428 100.00 0.70 0.040 0.580 0.560 3.60 2528 60.00 8.00 0.160 Melamine 13.07 113 428 100.00 0.80 0.040 0.580 0.560 3.60 2528 60.00 6.00 0.160 Reofos NTP 5.52 114 428 100.00 0.70 0.040 0.580 0.560 3.60 2528 60.00 8.00 0.160 Melamine 4.42 115 428 100.00 0.70 0.040 0.580 0.560 3.60 2528 60.00 8.00 0.160 Melamine 14.78 116 428 100.00 0.70 0.040 0.580 0.560 3.60 2528 60.00 8.00 0.160 Melamine 18.79 117 428 100.00 0.70 0.040 0.580 0.560 3.60 2528 60.00 0.00 0.000 None 0.00 118 428 100.00 0.70 0.040 0.580 0.560 3.60 2528 60.00 0.00 0.000 Melamine 15.39 119 428 100.00 0.70 0.040 0.580 0.560 3.60 2528 60.00 8.00 0.160 None 0.00 120 428 100.00 0.80 0.040 0.580 0.560 3.60 2528 60.00 8.00 0.160 Melamine 14.78 121 428 100.00 0.70 0.040 0.580 0.560 3.60 2528 60.00 6.40 0.120 Melamine 10.45 122 428 100.00 0.70 0.040 0.580 0.560 3.60 2528 60.00 0.00 0.000 None 0.00 123 428 100.00 0.70 0.040 0.580 0.560 3.60 2528 60.00 0.00 0.000 Melamine 15.39 136 428 100.00 0.70 0.040 0.580 0.560 3.60 2528 60.00 8.00 0.160 Melamine 13.94 137 428 100.00 0.70 0.040 0.580 0.560 3.60 2528 60.00 8.00 0.160 Aluminium 2.81 trihydrate 138 428 100.00 0.70 0.040 0.580 0.560 3.60 2528 60.00 8.00 0.160 Aluminium 5.47 trihydrate 139 428 100.00 0.70 0.040 0.580 0.560 3.60 2528 60.00 8.00 0.160 Aluminium 12.19 trihydrate 140 428 100.00 0.70 0.040 0.580 0.560 3.60 2528 60.00 10.00 0.200 Aluminium 6.42 trihydrate 141 428 100.00 0.70 0.040 0.580 0.560 3.60 2528 60.00 8.00 0.160 Aluminium 20.65 trihydrate 142 428 100.00 0.70 0.044 0.580 0.560 3.60 2528 60.00 8.00 0.160 Aluminium 18.79 trihydrate 143 428 100.00 0.70 0.040 0.580 0.560 3.60 2528 60.00 8.00 0.160 Aluminium 22.43 trihydrate 200 428 100.00 0.50 0.040 0.620 0.560 3.60 TDI 30.40 0.00 0.000 None 0.00 201 428 100.00 0.50 0.040 0.600 0.560 3.60 TDI 30.40 0.00 0.000 None 0.00 202 428 100.00 0.70 0.040 0.580 0.560 3.60 TDI 30.40 8.00 0.160 None 0.00 203 428 100.00 0.60 0.040 0.600 0.520 3.00 TDI 30.40 8.00 0.160 None 0.00 204 428 100.00 0.72 0.040 0.600 0.520 3.00 TDI 30.40 8.00 0.160 None 0.00 205 428 100.00 0.90 0.040 0.600 0.520 3.00 TDI 32.00 8.00 0.160 None 0.00 206 428 100.00 0.90 0.040 0.600 0.560 3.00 TDI 32.00 8.00 0.160 Melamine 15.25 207 428 100.00 0.90 0.040 0.600 0.560 3.00 TDI 32.00 8.00 0.160 Melamine 15.25 | The present invention relates generally to flexible polyurethane foam compositions that incorporate partially and/or totally exfoliated, clay based nanocomposite material. The invention also relates to the foams formed from the compositions, the preparation of the foams and uses thereof. | 2 |
BACKGROUND OF THE INVENTION
The present invention generally relates to balloon catheters for implanting stents within a body lumen. More particularly, the invention pertains to improvements to such catheters in order to more effectively and reliably achieve a uniform expansion of such stents while minimizing trauma to the vessel wall.
Stents or expandable grafts are implanted in a variety of body lumens in order to prevent collapse and thereby maintain the patency of such lumens. In the case of angioplasty applications, stents may also be implanted to prevent restenosis and thereby similarly maintain patency in the affected blood vessel. The stent is introduced into the body in a collapsed state to facilitate its transport to the deployment site where it is subsequently expanded. One approach for achieving expansion requires the stent in its contracted state to be fitted about an inflatable balloon disposed near the distal end of a catheter. The entire assembly is advanced through the vasculature and maneuvered into the desired position adjacent the section of lumen in need of support. Once in position, the balloon is inflated causing the stent to expand and engage the lumen walls. Various stent configurations and mechanisms have been devised to lock the stent into its expanded state in order to provide the requisite radial support to the lumen. Once the stent is fully expanded, the balloon is deflated and the catheter removed to leave the stent in place. Some stents are designed to permanently remain implanted while others are formed of materials that eventually become absorbed by the body.
The effectiveness of a stent can be diminished if it is not uniformly implanted within the body lumen. Stents expanded by the inflation of a balloon have a tendency to undergo a disproportionate rate and amount of radial expansion at their proximal and distal ends due to the typical drop off in hoop strength encountered near the ends of the structure. Thus the balloon expands along the path of least resistance in a "dog bone" pattern which is similarly imparted to the stent. Such non-uniformity in the implanted stent may be problematic in that the desired flow diameter of the stent may not be achievable without forcing the stent ends deep into the lumen tissue. In the case of arterial applications, the non-uniformity of surfaces encountered by blood flow may cause turbulence which in turn may lead to thrombosis.
A further disadvantage inherent in many stent configurations currently in use is that the structure undergoes longitudinal contraction as it is expanded radially. This characteristic, in conjunction with the tendency of the stent ends to expand first, has the potential for inflicting trauma on the lumen in which the stent is being deployed. Because the initial expansion of the stent ends may cause such ends to project into the lumen tissue, the subsequent radial expansion and hence longitudinal contraction of the center section would cause such ends to be pulled across the tissue. The rubbing or scraping of the stent against the tissue could cause injury.
This problem has been previously addressed in a number of ways including for example, the use of shape defining sleeves that are fitted about the balloon. It is the intent of such system to match the radial force profile generated by the balloon to the hoop strength of the stent and thereby achieve a constant rate of expansion over the length of the stent.
Alternatively, multiple balloon systems have been employed in an effort to control the expansion of the stent. In one system, "control" balloons are positioned proximally and distally to a centrally disposed expansion balloon. The two control balloons check axial growth of the expansion balloon and hence prevent axially displaced lateral loads to be placed on the stent. As a further alternative, the stent is positioned over multiple balloons of varied compliance arranged in series along the catheter. By sequencing the inflation of the balloons such that the central balloon is inflated first, a more uniform implantation of the stent is achieved.
Nonetheless, those concerned with the design, development and use of stent implantation systems recognize the desirability of further improvements in terms of performance efficiency, reliability and reductions in the cost of manufacture.
SUMMARY OF THE INVENTION
The present invention overcomes the shortcomings inherent in heretofore known deployment devices and techniques for balloon expandable stents. More specifically, the present invention provides for the uniform deployment of such stents while obviating the trauma that the stent's ends can inflict on the lumen walls. This is achieved more effectively, more reliably and with a device less costly to manufacture than was previously possible.
The invention provides for the center section to be expanded before the stent's ends are expanded using a two balloon system. As a result, the stent structure undergoes substantially its entire longitudinal contraction before the ends make contact with the vessel walls. The potential for the ends to be rubbed or scraped across the lumen tissue and cause injury is thereby effectively obviated. Such advantage is achieved with the use of two independently inflatable balloons concentrically fitted about a catheter. One balloon is positioned within the other wherein the outer balloon corresponds to the length of the stent while the inner balloon is substantially shorter. The inflated diameter of the outer balloon is approximately equal to the inflated diameter of the inner balloon or slightly smaller to accommodate the diminished hoop strength of the ends of the stent.
The deployment device of the present invention allows the stent to be initially expanded by the inner balloon, which by virtue of its smaller length causes only the center section of the stent to be radially expanded. The stent undergoes the majority of its longitudinal contraction during such initial expansion and only after such longitudinal contraction has been realized is the longer, outer balloon inflated to cause the stent's ends to expand and match the diameter of the center section. Trauma to the vessel walls by the stent ends is thereby effectively avoided. The configuration of some stents and the commensurate hoop strength variations along the length of such stents may require the outer balloon to have a slightly smaller inflated diameter than the inner balloon to avoid any "dog boning".
The use of only two balloons rather than the three balloons employed in some previously known in systems not only enhances reliability but reduces manufacturing cost. The fact that the use of two balloons requires a lesser number of surfaces to be bonded and sealed to the catheter surface also enhances the reliability of the device. Moreover, in the event of the failure of the inner balloon, any expansion fluid that is lost is contained by the outer balloon. Moreover, the outer balloon can effect sufficient expansion of the stent to allow the catheter to be disengaged therefrom and withdrawn.
These and other features and advantages of the present invention will become apparent from the following detailed description of a preferred embodiment which, taken in conjunction with the accompanying drawings, illustrates by way of example the principles of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an enlarged, sectioned and cross-sectional view of the stent delivery system of the present invention prior to deployment of the stent;
FIG. 2 is an enlarged, sectioned and cross-sectional view of the stent delivery system after inflation of the inner balloon;
FIG. 3 is an enlarged, sectioned and cross-sectional view of the stent delivery system after inflation of the outer balloon; and
FIG. 4 is an enlarged, section and cross-sectional view of the stent delivery system with the inner balloon deflated so that the outer balloon can be fully inflated.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The figures generally illustrate the stent delivery system of the present invention before, during and after deployment of the stent. Upon deployment, the stent serves to maintain the patency of the vessel in which it is positioned either by physically supporting the vessel wall or, in the case of some cardiovascular applications for example, by preventing restenosis.
FIG. 1 illustrates the system 12 in its pre-deployed pre-implanted state upon having been advanced to the deployment site within a body lumen 14. The system is introduced into the body in the conventional manner and may be advanced into position via a guide wire using conventional over-the-wire or rapid-exchange catheter techniques. Details of representative stents can be found in U.S. Pat. Nos. 5,421,955 (Lau et al.); 5,514,154 (Lau et al.); 5,603,721 (Lau et al.); and 5,569,295 (Lam), which are incorporated herein in their entirety by reference thereto. Details regarding balloon angioplasty catheters for use in performing angioplasty procedures, or that can be adapted to deliver intravascular stents are found in U.S. Pat. Nos. 4,771,777 (Horzewski et al.); 5,501,227 (Yock); 5,350,395 (Yock); 5,451,233 (Yock); 5,300,085 (Yock); 5,496,346 (Horzewski et al.); 5,061,273 (Yock); 5,040,548 (Yock); 4,748,982 (Horzewski et al.); 5,626,600 (Horzewski et al.); and 4,323,071 (Simpson et al.), which are incorporated herein in their entirety by reference thereto.
The device includes a catheter 16 having a distal end 18 and a proximal end 20 wherein such catheter has at least two inflation lumens 22, 24 formed therein. Each inflation lumen is in fluid communication with an inflation port 26,28 located near to the proximal end of the catheter.
Two inflatable balloons are fitted about the catheter near its distal end and are positioned such that the relatively shorter inner balloon 30 is wholly contained within the relatively larger outer balloon 32. The inner balloon is in fluid communication with lumen 24 via lumen port 34 while the outer balloon is in fluid communication with lumen 22 via lumen port 36 and optionally lumen port 38. The inflated diameters of the balloons are approximately equal or optionally, the outer balloon may have a slightly smaller or larger inflated diameter than the inner balloon. The length of the inner balloon preferably is approximately 70% that of the outer balloon, but preferably can be in the range of between 50% to 90% of the length of the outer balloon.
Fitted about the exterior surface of the outer balloon is the stent 40 that is to be deployed. The length of the outer balloon is selected so as to substantially conform to the length of the stent.
The balloons and catheter may be formed of polyethylene or other suitable materials well known in the art and the balloons are preferably bonded to the catheter as is also well known in the art.
In use, the catheter 16 with its balloons 30, 32 in their deflated state and supporting the stent 40 thereabout in its collapsed state is introduced into the body lumen 14 and advanced therethrough to the deployment site. Once in position, the inner balloon 30 is inflated via inflation port 28 to expand the center section of the stent 40 as is shown in FIG. 2. Such radial expansion causes the middle of the stent to expand radially outwardly and simultaneously contract longitudinally. However, because the inner balloon does not engage the ends 42, 44 of the stent, the ends do not expand substantially and remain distanced from the lumen wall. Trauma to the lumen wall that would otherwise be inflicted by the ends is avoided as the stent undergoes longitudinal contraction. Once the inner balloon is filly inflated, the outer balloon 32 is inflated via inflation port 26 as is shown in FIG. 3. In the event two lumen ports 36, 38 are formed in the inflation lumen, there is no need to first deflate the inner balloon 30. In the event only a single lumen port is employed, it is necessary to first reduce the pressure within the inner balloon in order to provide a fluid pathway for the entire interior of the outer balloon into fluid communication with such single port, as shown in FIG. 4. As the outer balloon expands, the ends 42, 44 of the stent are expanded to their fully deployed state to impart a uniformly expanded profile to the stent. Deflation of both balloons 30, 32 leaves the stent 40 in place against the lumen walls and frees the catheter 16 for retraction.
The balloons are preferably inflated by radiopaque fluid to facilitate monitoring of its position and shape by fluoroscopic means. The details and mechanics of balloon inflation vary according to the specific design of the catheter and are well known in the art. Similarly, different stent configurations may require the relative sizes of the balloons and the pressures to which they are inflated to be adjusted accordingly.
While a particular form of the invention has been illustrated and described, it will also be apparent to those skilled in the art that various modifications can be made without departing from the spirit and scope of the invention. The invention is not limited to the implantation of the stent in any particular body lumen nor to any particular configuration or size of the stent. Accordingly, it is not intended that the invention be limited except by the appended claims. | A stent deployment system and method wherein a two balloon catheter is used to expand the stent within a body lumen. The balloons are concentrically arranged about a dual lumen catheter wherein the inner balloon is smaller than the outer balloon. By first inflating the smaller balloon to expand only the center section of the stent, the stent undergoes substantially all of its longitudinal contraction before the ends make contact with the lumen tissue upon inflation of the larger outer balloon. | 0 |
BACKGROUND OF THE INVENTION
This invention relates to a sheet metal clip for affixing vertical edges of wallboard to the open side of an outwardly opening C-stud.
A problem has existed in attaching wallboard to a metal stud in a wall framing system which uses outwardly opening C-shaped vertical studs. An outwardly opening C-stud is a four-sided stud which includes three solid sides and one open side. The one open side has flanges along each edge of the open side and a wide opening therebetween. By "outwardly opening" it is meant that the open side of the stud is one of the two sides against which wallboard is to be affixed. This outwardly opening C-stud is to be distinguished from the common C-shaped metal screw stud which is intended for screw application of wallboard to two opposed solid sides, with only one solid web disposed perpendicular to the two screw flanges. The outwardly opening C-stud has two solid webs disposed perpendicular to the plane of the wallboards, to be affixed thereto.
The flanges along each edge of the open side of an outwardly opening C-stud do not provide enough surface area for screw attachment of wallboard thereto, creating the problem in attaching wallboards to outwardly opening C-studs, referred to above.
U.S. Pat. No. 3,266,209 discloses outwardly opening C-shaped metal struts which provide anchoring means for attaching kerfed or grooved marble slabs as facings for a wall. Anchor members attach the slabs to the struts. The anchor members, several embodiments are shown, all include a web portion which spaces the slabs from the struts, a kerf engaging portion on the end of the web, and a strut engaging portion. The strut engaging portions include bolted connections, outwardly struck spring elements which, with adjacent short arms, grasp the strut flanges and T-shaped extrusions which slidingly engage the strut flanges, all of which strut engaging portions are ree to rotate relative to the strut.
U.S. Pat. No. 2,116,737 discloses a clip for attaching wooden floorboards to an upwardly opening channel member, employing metal clips which rest on the bottom wall of the channel and protrude out of the top opening and engage the edges of the floorboards. These clips are free to rotate relative to the channel.
SUMMARY OF THE INVENTION
The present invention is directed to a novel clip for attachment of wallboards to the open side of an outwardly opening C-shaped metal stud. The clip includes a channel shaped body portion which extends across the open side of the C-stud and extends, further, around onto the two sides of the stud adjoining the outwardly opening open side. The clip further includes an upwardly and inwardly directed hanger portion which is shaped to fit between the stud open side flanges with a widened upper end which provides tabs which engage immediately behind the stud open side flanges.
The clip also includes sidewardly bent upper corners on the body portion for ease of engagement of the body portion with the stud.
The central part of the body portion can be a plane flat section of sheet metal to which wallboard is screw attached, using self-drilling, self-threaded wallboard screws, or it can be formed with outwardly protruding pointed legs for penetrating the edge of the wallboard.
The clip is easily combined with the stud, by inserting the widened upper end into the interior of the stud, through the stud opening, rotating the clip to position the widened end tabs behind the stud flanges, and then rotating the clip about a horizontal axis to position the body portion around the three sides of the stud, at which time the bent upper corners facilitate the positioning.
It is an object of the invention to provide an improved clip for affixing wallboard to outwardly opening C-studs.
It is a further object to provide a clip for outwardly opening C-studs having improved ease of affixation of the clip to the stud.
It is a still further object to provide outwardly opening C-studs clips having an instantly grasping body position which prevents clip rotation once wallboard is affixed to the clip.
BRIEF DESCRIPTION OF THE DRAWINGS
These and other objects and advantages will be more readily apparent when considered in relation to the preferred embodiments of the invention as set forth in the specification and shown in the drawings in which:
FIG. 1 is an isometric view of an outwardly opening vertical C-stud with a novel C-stud clip for attachment of wallboard to the stud open side.
FIG. 2 is a plan view of the stud and clip of FIG. 1, with wallboard attached to the C-stud clip.
FIG. 3 is an isometric view, similar to FIG. 1, of an outwardly opening C-stud with a modified form of C-stud clip for attachment of wallboard to the stud open side.
FIG. 4 is a plan view of the stud and clip of FIG. 3, with wallboard attached to the C-stud clip.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to FIGS. 1 and 2, there is shown a portion of a wall 8 including one of several vertically disposed, spaced apart, outwardly opening, C-shaped, elongate metal studs 10, mounted in a horizontal extending floor runner 12. Stud 10 includes an elongate back face 14 terminating along each back corner 16 with a perpendicularly disposed, elongate side web portion 18, each having a front corner 20 with a pair of elongate, front flanges 22, each extending from a front corner 20 toward the opposite flange 22, on the open front side 23 of stud 10. The flanges 22 include elongate, narrow face portions 24 and inwardly directed, elongate, narrow stiffening lips 25. Between the respective flanges 22 is an elongate opening 26.
Floor runner 12 has an elongate base 28 and two upwardly extending, elongate side walls 30. The side walls 30 of floor runner 12 engage the back face 14 of stud 10 and the front flanges 22.
It will be seen that stud 10 is thus disposed in floor runner 12 such that wallboard 32 is affixed against the back face 14 and the face portions 24 of front flanges 22. One wallboard 32 is screw attached directly to back face 14. The edges 34 of two other wallboards 32 are screw attached to a novel C-stud clip 36, which clip 36 is affixed to the open front side 23 of stud 10.
C-stud clip 36 is formed from sheet metal and includes a channel shaped body portion 38 and an upwardly and inwardly directed hanger portion 40.
Body portion 38 includes a central face portion 42 and two rearwardly directed, narrow side portions 44 which extend around the front corners 20 and along a narrow part of the web portions 18. The upper rearward corner 46 of each side portion 44 is bent sidewardly away from the stud web portion 18.
Hanger portion 40 is adjoined to body portion 38 along a horizontal fold line 48. Hanger portion 40 includes a narrow neck 50 and a wide upper end 52, forming tabs 54 which are disposed immediately behind the stud flanges 24 and lips 25. Hanger portion 40 is originally formed at a slight angle to, or in substantially the same plane as, the face portion 42 of body portion 38 and becomes bent considerably inwardly, along fold line 48, when body portion 38 is placed against the stud open front side 23, at a final angle of between about 20° and 80°.
Tabs 54 are thus urged firmly against the inner surface of flanges 22, providing a relatively firm grasp of the stud 10 by each clip 36, by the tendency of the clip to return to its original relatively coplanar relationship of hanger portion 40 and face portion 42.
Placement of clips 36 on a stud 10 consists of the steps of holding the clip 36 with the two tabs 54 directed vertically, respectively upwardly and downwardly, then inserting the hanger portion 40 through the opening 26, then rotating the clip to where the two tabs 54 are directed horizontally and disposed inwardly of flanges 22, and then rotating the clip about a horizontal axis to bring the face portion 42 firmly against the stud face portions 24. In so doing, the channel shaped body portion 38 will engage the stud on three sides, the open front side 23 and the two web portions 18. The placement of the side portions 44 against web portions 18 will be facilitated by the sidewardly bent corners 46, which will guide the body portion 38 into proper position.
The disposition of the body portion 38, engaging three sides of the stud 10 will be seen to provide a more stable relationship between clip 36 and stud 10.
Referring to FIGS. 3 and 4, a modified form of clip 36' is shown in which the face portion 42' further includes a pair of oppositely directed, outwardly protruding, pointed legs 60. Wallboard 32' is screw attached to the back face 14' of stud 10' and the edges 34' of two other wallboards 32' held against the stud 10' by the pointed legs 60 being inserted into the edges 34'.
Having completed a detailed disclosure of the preferred embodiments of my invention so that those skilled in the art may practice the same, I contemplate that variations may be made without departing from the essence of the invention. | A clip for permitting attachment of wallboard to the open side of an outwardly opening C-shaped metal stud, including a clip body portion which engages three sides of the metal stud for increased stability, and a clip hanger portion which extends upwardly and inwardly through the stud open front side and has tabs which engage behind the flanges of the stud open front side. | 4 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This is a continuation-in-part application claiming priority to International application PCT/IN2002/000195, filed Sep. 30, 2002, which designates the United States of America and claims the benefit of U.S. provisional application 60/391,717, filed Jun. 26, 2002, both of which are incorporated by reference herein to the extent they are not inconsistent with the disclosure herein.
TECHNICAL FIELD OF THE INVENTION
[0002] The present invention generally relates to a method of removing undesired byproducts from pyrolytic cracking of hydrocarbons. The invention more particularly relates to a method for removal of carbonyl compounds not only like acetaldehyde and other carbonyl compounds but also its polymer along with the other acidic gases like H 2 S and CO 2 that are formed when cracked gasses enter a caustic or an amine unit within an ethylene plant where the cracked gases are produced in a pyrolysis heater during the pyrolytic cracking of hydrocarbon such as naphtha, gas oil or ethane, propane, butane and such other hydrocarbons.
BACKGROUND OF THE INVENTION
[0003] In pyrolytic cracking operations, feed stocks such as ethane, propane, naphtha, kerosene, gas oil, fuel oil and the like undergo “cracking,” that is the removal of hydrogen, to form unsaturated hydrocarbons. Pyrolytic cracking also tends to produce oxygenated hydrocarbons, including carbonyl compounds such as acetaldehyde. In a typical operation, the cracked effluent stream is quenched, fractionated and compressed. Acidic contaminants such as hydrogen sulfide, carbon dioxide and mercaptans are then typically removed from the effluent.
[0004] During the scrubbing operation of these gases with caustic or amine some oxygenated compounds are removed. At the same time, however, the basic conditions in the scrubber tend to cause base-induced condensation reactions (due to aldol condensation mechanism) of the carbonyl compounds, including aldehydes (e.g., acetaldehyde) and/or ketones, which in turn result in the formation of polymers. These polymers deposit on the internal surfaces of the scrubber. As the mass of polymer grows, it leads to fouling and can eventually obstruct the flow of liquids through the system. This is undesirable, as the operating system must be shut down for a significant amount of time in order to remove the deposited polymer and clean the equipment. This operation itself is very expensive involving many man hours and fmancial loss.
[0005] The prior art systems treat caustic towers with an injection of a compound to inhibit the aldol condensation mechanism. In order to inhibit aldol condensation the prior art systems mostly use additives that are organic in nature and contribute to chemical oxygen demand for caustic used in the scrubbing process.
[0006] In addition, the prior art additives typically require additive to reactant (i.e., carbonyl compound) molar ratios to be of at least about 1:1 for effective performance. Further the adducts of the high molecular weight polymers with these compounds tend to be insoluble in the basic system. Thus, the prior art additives are ineffective for the purpose of maintaining unobstructed flow through the system and reducing significant maintenance time for removing the polymer deposits and cleaning the equipment.
[0007] A current practice in the industry is to treat the weak caustic in the caustic tower with gasoline or another aromatic fraction in order to remove the polymers before sending it to the spent caustic oxidation unit, in order to prevent fouling there. The resulting gasoline-containing stream causes disposal and operational problem, however. Likewise, routing the gasoline-containing stream to other operating units can cause problems due to the presence of the caustic, as it may affect pH, catalyst and other plant parameters.
[0008] Another current practice in the industry is to treat the caustic tower with organic additives and despite the various advances in the art it remains desirable to provide an alternative method to improve the performance of this particular unit in the industry. There have also been shortcomings discussed later when any of these additives have been used concurrently to provide a synergistic effect in such systems.
[0009] In the past, prevention of polymerization of oxygenated compounds, such as carbonyl containing organics in basic solutions, has been attempted by process of inhibition only by adding amine compounds such as hydroxylamine hydrochloride, hydroxylamine sulfate, hydrazine, carbohydrazides and the like. Several patents which relate to methods of inhibiting carbonyl fouling due to polymerization are listed below. It is found that these patents discuss only the removal of carbonyl compounds but fail to address the issue of polymers which are formed as a result of polymerization of unscavenged portion of the carbonyl compounds during the use of inhibiting additive and also of polymers already existing in the system. Thus these patents discuss only the method of inhibition of polymerization.
[0010] U.S. Pat. No. 4,673,489 to Roling discloses using hydroxylamine and its salts of hydrochloric acid and sulfuric acid to inhibit polymer formation caused by condensation reactions of aldehydes contained in caustic scrubber units. One disadvantage of the method is that the additive has to be used in almost molar proportion. The other disadvantage is that these chemicals are expensive and must be over fed to the caustic wash unit system. This patent does not disclose a solution to the removal of carbonyl compounds and their polymers that remain unscavenged in the inhibition; process, nor does it provide for removal of already existing polymers.
[0011] U.S. Pat. No. 4,952,301 to Awbrey discloses using ethylenediamines, with the molecular formula NH sub 2 ( CH sub 2 CH sub 2 NH ) sub x H were x is an integer ranging from about 1 to about 10, to inhibit carbonyl based fouling, particularly aldehyde fouling, that often occurs during caustic scrubbing of liquid or gas phase hydrocarbon streams in the base wash unit. This patent similarly does not provide a solution to removal of carbonyl compounds and polymers thereof that remain unscavenged during the inhibition process, nor does it solve the problem of removal of already existing polymers.
[0012] U.S. Pat. No. 5,264,114 granted to Dunbar also discloses the use of amine compounds to inhibit the deposition of foulants during caustic washing of the hydrocarbon gases contaminated with the carbonyl compounds. The method comprises of treating the said hydrocarbon gases with an aqueous amine solution, wherein 2 to about 5000 ppm of amine compound is selected from a group of organic compounds of the formula RNH 2 and R 2 NH, R being selected from the group of alkyl or aryl groups. This patent does not discuss the problems related to removal of already existing polymers, nor does it provide solution for removal of carbonyl compounds and polymers thereof which are unscavenged during the inhibition process.
[0013] Carbohydrazide has been disclosed as useful for inhibiting polymeric fouling deposits during the caustic scrubbing of pyrolytically-produced hydrocarbons contaminated with oxygen-containing compounds in U.S. Pat. No. 5,160,425 to Lewis. Similarly, this patent does not discuss the problems related to removal of already existing polymers, nor does it provide solution for removal of carbonyl compounds and polymers thereof which are unscavenged during the inhibition process.
[0014] U.S. Pat No. 5,288,394 to Lewis and Rowe describes a method of inhibiting formation of polymeric fouling deposits after the caustic scrubbing of hydrocarbon stream contaminated with oxygenated compounds. The scrubbing is performed with a basic washing solution having pH more than 7, and comprising at least one hydrazide compound. Similarly, this patent does not discuss the problems related to removal of already existing polymers, nor does it provide solution for removal of carbonyl compounds and polymers thereof which are unscavenged during the inhibition process.
[0015] U.S. Pat. No. 5,194,143, granted to Roling describes and claims a method for inhibiting the formation of polymeric based fouling deposits during the basic washings of olefins containing hydrocarbon contaminated with oxygenated compounds comprising adding to the wash about 1 to 10000 ppm acetoacetate ester compound having the formula CH sub 3 COCH sub 2 c sub x H sub, where x is an integer from about 1 to about 8 and y is an integer from about 3 to about 17. Similarly, this patent does not discuss the problems related to removal of already existing polymers, nor does it provide solution for removal of carbonyl compounds and polymers thereof which are unscavenged during the inhibition process.
[0016] U.S. Pat. No. 5,220,104 to McDaniel at al. discloses the use of percarbonate salts for inhibition of fouling. Similarly, this patent does not discuss the problems related to removal of already existing polymers, nor does it provide solution for removal of carbonyl compounds and polymers thereof which are unscavenged during the inhibition process.
[0017] U.S. Pat No 5,770,041 to Lewis et al. describes the use of certain aldehydic compounds without alpha hydrogen atom or the use of non-enolizable aldehydes like formaldehyde, glyoxal and the like as aldol inhibitor. In this case the inhibitors are to be used at least thrice the molar ratio per mole of carbonyl species. Similarly, this patent does not discuss the problems related to removal of already existing polymers, nor does it provide solution for removal of carbonyl compounds and polymers thereof which are unscavenged during the inhibition process.
[0018] U.S. Pat No 5,710,455 to Bhatnagar et al. discloses the use of certain organic amine inhibitors like sulfanilic acid for inhibiting the aldol condensation. Similarly, this patent does not discuss the problems related to removal of already existing polymers, nor does it provide solution for removal of carbonyl compounds and polymers thereof which are unscavenged during the inhibition process.
[0019] All the patents of the prior art discussed above discuss treatment of the caustic with injection of a compound only to inhibit polymer formation by aldol condensation mechanism. They do not, however, solve the problem of removal of the polymers already present in the system.
[0020] Apart from the above mentioned disadvantages there are serious technical problems that exist with the prior art. For instance, one serious technical problem is the extremely rapid polymer formation; it typically takes place within few minutes, rendering impossible the complete scavenging of the carbonyl compounds by any known polymerization inhibition process. Obviously, an important requirement for inhibition of polymerization is that the inhibitor be present in the caustic tower before the carbonyl compounds enter the tower. Delay in supply of the inhibitor or incomplete availability of the inhibitor in the caustic tower will cause the carbonyl compounds to polymerize within few minutes, a process which is very detrimental to the unit leading to fouling. The unscavenged part of carbonyl compounds polymerizes and deposits on the trays, leading to fouling and plugging of the equipment, and eventually to equipment failure.
[0021] Another important technical problem is that the inhibitor used by other researchers can react only with nonpolymerized carbonyl compounds and with very low molecular weight caustic soluble species (2 or 3 repeating units of acetaldehyde), but not with high molecular weight polymers (having greater than 3 repeating units of acetaldehyde). It is precisely the high molecular weight polymers that are insoluble in the caustic system, thereby depositing and fouling the equipment. Hence there is a need to develop a method which that will not only inhibit the formation of polymers, but will also lead to dissolving the polymers already existing in the caustic tower and its downstream units.
SUMMARY OF THE INVENTION
[0022] During scrubbing operations in the caustic or amine towers in the chemical industry, condensation reactions of carbonyl compounds lead to formation of polymers, which further leads to fouling and obstructing the flow of liquid through the system. The present invention provides a method to mitigate fouling that occurs due to polymerization of carbonyl compounds. This mitigation is achieved by using certain inorganic salts like sodium dithionite, sodium metabisulphite, certain amino acids like amino caproic acid, sulfanilic acid, and combinations thereof as additives for washes of caustic towers. The compounds disclosed in this invention inhibit polymer formation. The compounds scavenge the carbonyl compounds thereby inhibiting polymerization; in addition, the compounds dissolve polymers formed as the result of the reaction, as well as the polymers already existing in the caustic tower. Furthermore, the present invention can be used along with the caustic in the caustic tower, i.e., the compounds of the invention can be premixed with the caustic used for making the scrubbing solution.
[0023] Accordingly, one objective of the present invention is the inhibition of the formation of polymers of carbonyl compounds in a caustic scrubber; a benefit of this is the inhibition of fouling that occurs due to oxygenated hydrocarbons. Another objective of the invention is to dissolve the polymers in a caustic scrubber which are formed in spite of the inhibitory action, as well as to dissolve the polymers that exist in the scrubber. One objective of the invention is to reduce the concentration of oxygenated hydrocarbons, particularly carbonyl compounds in caustic or amine towers used in the chemical industry, and equipment and products thereof. Yet another objective of the invention is to scavenge oxygenated hydrocarbons without posing polymerization problems and without interfering with plant operations, nor with individual process operations. Still further objective of the invention is to provide an inventive product which can be premixed with the caustic that is used for making the scrubbing solution. Yet further objective is to develop an inventive combination of chemicals that react with nonpolymerized carbonyl compounds, with low molecular weight species, and with high molecular weight carbonyl polymers, such that the reacted adduct is soluble in the caustic solution, thereby preventing plugging and fouling of the equipment.
BRIEF DESCRIPTION OF THE DRAWINGS
[0024] FIGS. 1 and 2 depict chemical compounds useful in the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0025] The present invention discloses a method of inhibiting polymer formation and also for dissolving polymers formed during reaction, as well as dissolving of existing polymers. The invention is directed toward inhibition of polymerization of carbonyl compounds, both low molecular weight species and high molecular weight polymers. Such polymers lead to deposit formation in caustic or alkaline scrubbers that are used for scrubbing acidic gases (e.g., carbon dioxide, hydrogen sulfide) from the effluent streams formed during pyrolytic cracking of hydrocarbons like naphtha, ethane, and propane. The cracking operations also produce oxygenated compounds such as vinyl acetate or acetaldehyde, which undergo polymerization under the alkaline conditions in the scrubber. Upon hydrolysis under alkaline conditions, vinyl acetate releases acetaldehyde, which further contributes to the buildup of polymeric deposits.
[0000] Use of Inorganic Salts Such as Sodium Dithionite
[0026] The most preferred embodiment of the present invention includes a method wherein certain inorganic salt, like sodium dithionite, is introduced into the feed stream to caustic wash unit system, in order to mitigate fouling. The addition of sodium dithionite causes mitigation of fouling through a dual function. First, sodium dithionate inhibits polymerization, by dissolving the polymers formed during the reaction. If a polymer is formed by escaping the inhibition action or if a polymer already exists in the system before the addition of the additive, sodium dithionite dissolves the same. Second, addition of sodium dithionite mitigates fouling by dissolving the polymers already existing in the caustic scrubber.
[0027] In this most preferred embodiment of the present invention the inorganic salt like sodium dithionite should be added to the alkaline scrubber in an amount wherein a molar ratio of carbonyl compound to inorganic salt is from about 1:0.01 to about 1:25 mole, preferably from about 1:0.05 to about 1:0.005 mole, and more preferably from about 1:1 to about 1:0.01 mole. The preferred amount of additive ranges from about 0.5 to about 1,000,000 parts of additive per one million part of the aqueous scrubbing medium used in the caustic wash unit system; more preferably, the amount of additive ranges from about 25 to about 200 ppm. The sodium dithinoite as an additive can be added as neat product or in any form available commercially, or as a solution in water or alkali.
[0028] Referring to experiments 1 and 2 in Table 1, the use of 0.15 M sodium dithionite yields relative transmittance value T of 68.5%, as compared to the 0.5% T value of the blank without inhibitor. The blank run in the example corresponds to the amount of unscavenged carbonyl low molecular weight species, high molecular weight polymers, and already existing polymer. This example demonstrates the efficiency of sodium dithionite in inhibiting polymer formation.
[0029] Referring to experiments 1 and 2 in Table 3, the T value is 0.5% for the blank and 62.5% for sodium dithionite. This example suggests the effect of addition of sodium dithionite on dissolving of polymer deposits. Those skilled in the art are aware that even a slight delay in the addition of additive leads to formation and deposition of polymers. Sodium dithionite has the ability to dissolve deposited polymers.
[0000] Use of Combinations of Inorganic Salt Like Sodium Dithionite and Organic Aliphatic Amino Acid and its Derivatives
[0030] Another embodiment of the present invention includes a method wherein said inorganic salt sodium dithionite is blended in synergistic combination with aliphatic amino acid, including but not limited to 6 amino caproic acid, to mitigate polymerization effects in a caustic wash unit system. The blend of sodium dithionite and aliphatic amino acids mitigates fouling through a dual function, of (i) inhibiting polymer formation and dissolving polymers formed during the reaction, as well as (ii) dissolving polymers already existing in the caustic scrubber.
[0031] In this embodiment of the present invention the blend of inorganic salt (like sodium dithionite) and the aliphatic amino acid (like 6 amino caproic acid) is added to the alkaline scrubber in an amount wherein a molar ratio of carbonyl compound to said blend is from about 1:0.01 to about 1:25 mole, preferably from about 1:0.05 to about 1:0.005 mole, and more preferably from about 1:1 to about 1:0.01 mole. The amount of additive ranges from about 0.5 to about 1,000,000 parts of inhibitor per one million part of the aqueous scrubbing medium used in the caustic wash system, more preferably, the amount of additive ranges from about 25 to about 200 ppm.
[0032] The combination of inorganic salt and the aliphatic amino acids can be added either as blend or as individual components in neat or solution form. The amino acid can be added either as neat product or as an aqueous solution containing from about 0.05 to about greater than about 60 weight percent, preferably from about 18 to about 38 weight percent. Amino acids that are particularly suited for use in the accordance with this embodiment of the invention include, but are not limited to, 6 amino acid such as the amino hexanoic acid made from epsilon caprolactam, glycine, or taurine, or any compound having one of the structures described in FIGS. 1 and 2 . Also suitable are the derivatives, isomers, and inorganic or organic salts of these compounds. The amino acids mentioned above can be used in its salt form or as pure amino acid or impure form or combinations thereof.
[0033] Referring to experiments 1, 2, and 3 in Table 2, the results further support the advantageous synergistic effect of the compounds used to inhibit polymerization. With 0.1 M sodium dithionite, the relative transmittance value T is 18.5%. With 0.026 M amino caproic acid, the relative transmittance value T is 0.3%; however, the 0.126 M combination of sodium dithionoite and amino caproic acid yields relative T value of 82%. The experiment 4 in Table 2 shows that the amino caproic acid synthesized from caprolactam shows similar behavior. These experiments demonstrate the advantage of combining sodium dithionite and amino caproic acid to inhibit polymer formation.
[0034] Referring to experiments 1, 2, 3 and 4 in Table 3, the combination of sodium dithionite and amino caproic acid also acts synergistically in dissolving the polymer. The T value for individual components is 62.5% for 0.5 M sodium dithionite, and 0.5% for 0.087 M amino caproic acid, but the blend of the two compounds at a total mole ratio of 0.5879 has a T value of 77.05%. This example demonstrates the advantageous effect of combining sodium dithionite and amino caproic acid to inhibit polymerization and to dissolve polymer residues.
[0000] Use of Combinations of Inorganic Salts Like Sodium Dithionite and Lactam and its Derivatives
[0035] Further embodiment of the present invention includes a method, wherein blends of inorganic salt like sodium dithionite and certain lactams, including but not limited to epsilon caprolactam, are used to mitigate the effects of polymerization in the caustic wash unit system. Thus a blend of inorganic salts like sodium dithionite and lactam, particularly epsilon caprolactam, not only inhibits polymer formation but also dissolves the polymers already existing in the caustic scrubber.
[0036] In this embodiment of the present invention the blend of inorganic salt (like sodium dithionite) and the lactam (like epsilon caprolactam) is added to the alkaline scrubber in an amount wherein a molar ratio of carbonyl compound to said blend is from about 1:0.01 to about 1:25 mole, preferably from about 1:0.05 to about 1:0.005 mole, and more preferably from about 1:1 to about 1:0.01 mole. The amount of additive ranges from about 0.5 to about 1,000,000 parts of inhibitor per one million part of the aqueous scrubbing medium used in the caustic wash system; more preferably, the amount of additive ranges from about 25 to about 200 ppm. Inorganic salts and the lactam or sultam can be added either individually or in combination, in neat or solution form. The lactam can be added either as neat product or as an aqueous solution containing from about 0.05 to about greater than about 60 weight percent, preferably from about 18 to about 38 weight percent. Lactams that are particularly suited for use in the accordance with this embodiment of the invention include, but are not limited to, epsilon caprolactam. However, any compound having one of the structures described in FIGS. 1 and 2 should be effective. Also suitable are the derivatives, isomers, and inorganic or organic salts of these compounds.
[0037] When amino acids or lactams are used along with the inorganic salts, particularly sodium dithionite, they react with unscavenged carbonyl compounds, low molecular weight species, high molecular weight polymers and with already existing polymers. Acting synergistically, the amino acid and the inorganic salt solubilize the polymers formed and prevent precipitation and fouling of the equipment.
[0038] Referring to experiments 1, 7, and 8 in Table 2, a highly synergistic effect on inhibition of polymerization is seen between sodium dithionite and caprolactam. Individually used 0.1 M sodium dithionite has a T value of 18.5%; individually used 0.3 M caprolactam has a T value of 0.4%. Shown in experiment eight, 0.25 M caprolactam and sodium dithionite has a T value of 82.9%. This shows the advantage of combining sodium dithionite and caprolactam in inhibiting polymerization.
[0039] Experiments no 2, 6 and 7 in Table 3 show a synergistic effect of sodium dithionite and caprolactam on dissolving of polymers. Used individually, 0.5 M sodium dithionite has a relative T value of 62.5%; used individually, 0.3 M caprolactam has a T value of 11.4%. The combination of both sodium dithionite and caprolactam has a T value of 69.7%. This shows the advantage of combining sodium dithionite and caprolactam in dissolving the existing polymers.
[0000] Use of Combinations of Inorganic Salt Like Sodium Dithionite and Aromatic Amino Acid and its Derivatives
[0040] Yet another embodiment of the present invention includes a method wherein, to mitigate the effects of polymerization in the caustic wash unit system, sodium dithionite is blended in synergistic combination with aromatic amino acids including, but not limited to, sulfanilic acid. The blends of inorganic salt like sodium dithionite and aromatic amino acids, particularly sulfanilic acid, inhibit polymer formation. In this embodiment of the present invention the blend of inorganic salt, like sodium dithionite, and the aromatic amino acid, like sulfanilic acid, are added to the alkaline scrubber in an amount wherein the molar ratio of carbonyl compound to said blend is from about 1:0.01 to about 1:25 mole, preferably from about 1:0.05 to about 1:0.005 mole, and more preferably from about 1:1 to about 1:0.01 mole. The amount of additive ranges from about 0.5 to about 1,000,000 parts of inhibitor per one million part of the aqueous scrubbing medium used in the caustic wash system, more preferably the amount of additive ranges from about 25 to about 200 ppm. The inorganic salt and the aromatic amino acids can be added either as blend or as individual components in neat or solution form. The aromatic amino acid can be added either as neat product or as an aqueous solution containing from about 0.05 to about greater than about 60 weight percent, preferably from about 18 to about 38 weight percent. Aromatic amino acids that are particularly suited for use in the accordance with this embodiment of the invention include, but are not limited to, aromatic amino acid such as sulfanilic acid, or any compound having one of the structures described in FIGS. 1 and 2 . Also suitable are the derivatives, isomers, and inorganic or organic salts of these compounds. The aromatic amino acids mentioned above can be used in its salt form or as pure aromatic amino acid or impure form or combinations thereof.
[0041] Referring to experiment 1, 5, 6 of table 2, a synergistic effect of inhibition of polymerization is seen when sulfanilic acid and sodium dithionite are used. The relative T value of individually used 0.1 M sodium dithionite is 18%, for 0.16 M sulfanilic acid T is 0.2%, whereas 0.26 M of the blend has a T value of 86.7%. This shows the advantage of combining sodium dithionite and sulfanilic acid to inhibit polymer formation.
[0000] Use of Inorganic Salt Like Sodium Metabisulphite
[0042] Still another embodiment of the present invention includes a method wherein certain inorganic salt, like sodium metabisulphite, is introduced into the feed stream to a caustic wash unit system to mitigate fouling, by inhibiting polymer formation. In this embodiment of the present invention the inorganic salt, like sodium metabisulphite, is added to the alkaline scrubber in an amount wherein the molar ratio of carbonyl compound to inorganic salt is from about 1:0.01 to about 1:25 mole, preferably from about 1:0.05 to about 1:0.005 mole, and more preferably from about 1:1 to about 1:0.01 mole. The preferred amount of additive ranges from about 0.5 to about 1,000,000 parts of additive per one million part of the aqueous scrubbing medium used in the caustic wash unit system, more preferably the amount of additive ranges from about 25 ppm to about 200 ppm. The sodium metabisulphite as an additive can be added as neat product or in any form available commercially or as a solution in water or alkali.
[0043] Also referring to the experiments 10, 14, and 7 in Table 1, 0.125 M of sodium bisulphite has a relative T value of 2.8%, 0.125 M of sodium sulphite has a T value of 0.35%, whereas 0.125 M of sodium metabisulphite has a T value of 80.7%. These experiments demonstrate the superiority of using sodium metabisulphite to inhibit polymer formation.
[0000] Use of Combinations of Inorganic Salts Like Sodium Dithionite and Sodium Metabisulphite
[0044] Yet another embodiment of the present invention includes a method wherein said inorganic salt sodium dithionite is blended in synergistic combination with another inorganic salt like sodium metabisulphite, to mitigate the effects of polymerization in the caustic wash unit system. In this embodiment of the present invention the blend of inorganic salts, like sodium dithionite and sodium metabisulphite, is added to the alkaline scrubber in an amount wherein the molar ratio of carbonyl compound to said blend is from about 1:0.01 to about 1:25 mole, preferably from about 1:0.05 to about 1:0.005 mole, and more preferably from about 1:1 to about 1:0.01 mole. The amount of additive ranges from about 0.5 to about 1,000,000 parts of inhibitor per one million part of the aqueous scrubbing medium used in the caustic wash system, more preferably the amount of additive ranges from about 25 to about 200 ppm. The inorganic salts can be added as a blend or as individual components. The salts can be added either as neat products, as aqueous solutions, or as alkaline solutions or blends thereof.
[0045] Referring to experiment 1, 9, 12 in table 2, a synergistic effect of polymer inhibition is seen between sodium metabisulphite and sodium dithionite. The % T value of the individual components that is sodium dithionite in molar of 0.1 is 18 , for sodium metabisulphite in the mole ratio of 0.0.09 the % T value is 35 where as the blend at the sum total mole ratio of 0.19 has a % T value of 93%. Thus this proves the excellent efficiency of combination of sodium dithionite and sodium metabisulphite in effecting inhibition of polymer formation.
[0000] Premixed Additives for Caustic Wash Unit Systems Serve Carbonyl Scavenging Function
[0046] Yet further embodiment of the present invention includes a method of converting the usual caustic wash unit system, commonly known as caustic tower, into a carbonyl scavenging tower. This conversion can be achieved by premixing the additives described above, either individually or as combinations of compounds, with the caustic solution, before the caustic solution is admitted into the caustic tower. In the current practice, the additives are externally added to the tower by a separate supply unit. One disadvantage of this practice is that the tower may run only with caustic solution without additive in case of failure of the unit that supplies the additive. Those skilled in the art are aware that even a minor delay is detrimental for the unit because the polymer formation of the carbonyl compounds is extremely rapid and takes place within a few minutes.
[0047] To serve the purpose of the invention, the additive should be stable in the caustic solution for reasonably long period of time. Referring to examples 4 and 5, the inorganic salts like sodium dithionite and sodium metabisulphite, once added to the caustic solution, effectively prevent polymer formation for up to 20 days. This is a very economical solution for scavenging of carbonyl compounds in the petrochemical industries.
[0048] For purposes of this invention, low molecular weight species are defined as polymers having 2 or 3 repeating units of acetaldehyde, whereas high molecular weight polymers are defined as polymers having greater than 3 repeating units of acetaldehyde.
[0049] The following Examples are merely illustrative of some embodiments of the present invention and the manner in which it is can be performed, and are not intended to limit the scope of the claimed invention in any way:
EXAMPLE 1
[0050] Caprolactam (18 g, 0.1593 mole), sodium hydroxide (7 g, 0.175 mole), and 75.0 g water were added to a clean round bottom flask equipped with a thermometer, stirrer and condenser. The mixture was well agitated and heated to 105-120° C. for a period of six hours. Small samples were periodically withdrawn and checked for conversion using HPLC. The conversion of epsilon caprolactam to six amino hexanoic acid was greater than 75%.
EXAMPLE 2
[0051] Twenty ml of 10% NaOH solution were added to a 50 ml stoppered conical flask. Desired inhibitor in solution or in solid form was also added, followed by the addition of 1 ml vinyl acetate. The mixture was shaken well and kept in an oven for 24 hours at 55° C. A blank was prepared wherein all reagents except the inhibitor were added. At the end of 24 hours the contents of the flask were visually checked for clarity or any deposits, and UV readings were measured. The results, as an average of two or free reading, are shown in the Tables below.
TABLE 1 Use of individual compounds to inhibit polymer formation. Transmittance Relative Expt Mole at 800 nm absorbance No. Compounds gms ratio (T %) at 720 nm Observation 1 Blank nil nil 0.5 2.5 Red hazy liquid with precipitate 2 Sodium 0.2075 0.125 68.5 0.2575 Red slightly hazy dithionite liquid 3 Sodium 0.4715 0.250 89.55 0.0475 Red clear liquid dithionite 4 Sodium 0.943 0.5 90 0.042 Faint red clear dithionite liquid 5 Sodium 1.886 1.0 80.35 0.09 Colorless liquid dithionite 6 Sodium 0.1281 0.0625 0.466 2.54 Red hazy liquid metabisulphite 7 Sodium 0.2562 0.125 80.7 0.179 Red clear liquid metabisulphite 8 Sodium 0.549 0.25 86.4 0.113 Red clear liquid metabisulphite 9 Sodium 2.089 1.0 87.3 0.066 Red clear liquid metabisulphite 10 Sodium 0.140 0.125 2.8 1.80 Hazy red liquid bisulphite 11 Sodium 0.338 0.30 86.1 0.133 Red clear liquid bisulphite 12 Sodium 0.563 0.50 86 0.1035 Red clear liquid bisulphite 13 Sodium 1.127 1.0 89.1 0.092 Red clear liquid bisulphite 14 Sodium sulphite 0.170 0.125 0.35 2.653 Red hazy liquid 15 Sodium sulphite 0.682 0.5 83.6 0.130 Red clear liquid 16 Sodium sulphite 1.365 1.0 89.2 0.08 Red clear liquid 17 Sodium sulfate 1.539 1.0 5.9 1.904 Hazy liquid with gummy polymer 18 Sodium 1.496 1.0 4.4 1.332 Same as above hydrogen sulfate
[0052]
TABLE 2
Use of blends to inhibit polymer formation
Transmittance
Relative
Expt
Moles
Moles
Total
at 800 nm
absorbance
No.
Compounds
Gms
of
of
moles
(T %)
at 720 nm
Observation
1
Sodium
0.1
—
0.1
18.5
0.842
Red hazy
Dithionite
liquid
2
Amino
0.0372
—
0.026
0.026
0.3
2.571
Closer to
caproic acid
blank
3
Sodium
0.1886
0.1
0.126
82
0.183
Red clear
Dithionite +
transparent
Amino
0.0372
0.026
liquid
caproic acid
4
Sodium
0.1886
0.1
0.126
81.0
0.210
Red clear
dithionite +
transparent
Product of
0.09
0.026
liquid
Example 1
ml
5
Sodium
0.1886
0.1
0.260
86.7
0.1195
Red clear
dithionite +
transparent
sulfanilic acid
0.3
0.160
liquid
6
Sulfanilic acid
0.30
0.160
0.160
0.2
2.872
Red brown
hazy with
particles
7
caprolactam
0.3673
0.3
0.3
0.4
2.783
Dark red
slight hazy
liquid with
some dispersed
particles
8
Caprolactam +
0.1836
0.15
0.250
82.9
0.176
Red clear
sodium
0.1886
0.1
transparent
dithionite
liquid
9
Sodium meta
0.1853
0.09
0.190
93.3
0.067
Faint Red
bisulphite +
clear
sodium
0.1866
0.1
transparent
dithionite
liquid
10
Sodium
0.1132
0.06
0.123
81
0.285
Red clear
dithionite +
transparent
Amino
0.0888
0.0625
liquid
caproic acid
11
Amino
0.0888
0.0625
0.0625
0.3
2.872
Same as
caproic acid
blank
12
Sodium
0.09
35
Red hazy
metabisulphite
liquid with
polymer
particles
EXAMPLE 3
[0053] Twenty ml of 10 % NaOH solution were pipetted into a 50 ml stoppered conical flask. One ml of vinyl acetate solution was added. The mixture was shaken well and kept in an oven for 15 minutes. During this period, the vinyl acetate was hydrolyzed and polymerized to form insoluble products. After 15 minutes the desired amount of inhibitor was added. One control sample was prepared without inhibitor. The flask was shaken well and kept in an oven for 24 hours. After 24 hours, the flask was checked visually for clarity and for any deposits. In some cases, UV transmittance was measured for comparison.
TABLE 3 Use of compounds and their blends to dissolve formed polymers Transmittance Relative Expt Moles Total at 800 nm absorbance No. Compounds gms moles of moles (T %) at 720 nm Observation 1 blank nil nil nil nil 0.5 2.5 Red turbid liquid with polymer particles 2 Sodium 0.943 0.5 — 0.5 62.5 0.202 Yellow Dithionite clear liquid with few particles 3 Amino 0.125 0.087 0.087 0.5 2.709 Same as caproic acid above 4 Sodium 0.943 0.5 0.5879 77.05 0.1125 Red clear Dithionite + transparent Amino 0.125 0.0879 liquid caproic acid 5 Sodium 0.943 0.5 0.5879 85.7 0.07 Red clear dithionite + transparent Product of 0.3 0.087 liquid Example 1 ml 6 caprolactam 0.3673 0.3 0.3 11.4 1.095 Hazy red liquid with particles 7 Sodium 0.943 0.5 0.8 69.7 0.171 Clear red dithionite + liquid with caprolactam 0.3673 0.3 few particles 8 caprolactam 0.6122 0.5 0.5 64.0 0.387 Dark red liquid with few particles 9 caprolactam 1.224 1.0 1.0 70.0 0.315 Red clear liquid 10 Sodium 1.127 1.0 1.0 10.7 Brown hazy bisulphite liquid with heavy polymer particles 11 Sodium 1.0 1.0 1.0 18.7 0.729 Brown hazy metabisulphite liquid with heavy polmer particles 11 Sodium 1.365 1.0 1.0 4.3 1.389 Brown hazy sulphite liquid with heavy polymer particles
EXAMPLE 4
[0054] The stability of the caustic solution was also tested. For this experiment, 0.3 mole strength of sodium dithionite was prepared in 10% NaOH solution. The transparency of this sodium dithionite solution was periodically tested. To 20 ml of the solution, 1 ml vinyl acetate was added. The flask was shaken well and kept in the oven at 55 ° C. for 24 hours. The detailed results are listed in Table 4 below.
TABLE 4 Test of the stability of the caustic solution Relative transmittance Relative Sr. (T %) at absorbance No. Hours 800 nm at 720 nm Observation 1 24 90.3 0.122 Red clear transparent liquid 2 192 85.3 0.145 Red clear transparent liquid 3 240 87.9 0.140 Red clear transparent liquid 4 360 90.9 0.129 Red clear transparent liquid 5 480 87.3 0.142 Red clear transparent liquid
EXAMPLE 5
[0055] The effect of sodium metabisulphite was also tested. In that case, 0.2 M of sodium dithionite was prepared in 10% NaOH solution. The transparency of this sodium dithionite solution was periodically tested. To 20 ml of the solution 1 ml vinyl acetate was added and shaken well. The flask was kept in the oven at 55 deg c for 24 hrs. The details of the result are listed in the Table 5 given below
TABLE 5 Effect of sodium metabisulphite. Relative transmittance Relative Sr. (T %) at absorbance No. Hours 800 nm at 720 nm Observation 1 24 90.7 0.095 Red clear transparent liquid 2 72 90.8 0.109 Red clear transparent liquid 3 168 90.3 0.105 Red clear transparent liquid 4 216 88.7 0.118 Red clear transparent liquid 5 336 90.4 0.116 Red clear transparent liquid
[0056] While the present invention has been described herein in terms of various embodiments, one of ordinary skill in the art will recognize that modification to the embodiments can be made without departing from the scope of the claimed invention. While the above description contains many specificities, these should not be construed as limitations in the scope of the invention but rather as exemplifications of different embodiments thereof. Accordingly, the scope of the invention should be determined not by the embodiments illustrated but by the appended claims and their legal equivalents. | A method for mitigating fouling in a wash unit used in a hydrocarbon cracking process wherein the fouling is due to the presence of polymers and deposits thereof formed by condensation of carbonyl compounds contained within a feed stream of the wash unit. In one embodiment, the invention provides a method of mitigating fouling in a wash unit by introducing into the feed stream an effective amount of an additive including: an inorganic salt of dithionite; and an epsilon caprolactam or a 6-amino caproic acid derivable therefrom. The additive scavenges the carbonyl compounds contained within the feed stream and dissolves deposits of the polymers to thereby mitigate fouling in the wash unit. | 8 |
FIELD OF THE INVENTION
The present invention pertains to thermal barrier coatings applied to protect components in high temperature environments. In particular, the present invention describes a composition and method for applying a thermal coating system.
BACKGROUND OF THE INVENTION
Systems located or operated in high temperature environments often include thermal barrier coatings (TBCs) on components to reflect heat and prevent the components from absorbing heat. For example, jet engines and gas turbines include combustors and turbines designed to operate in very demanding high temperature and pressure environments. As a result, many components, such as combustor liners, turbine blades, turbine casings, and rotors routinely operate in high temperature environments that approach or exceed the melting temperature of the constituent elements included in the components. A TBC applied to the surface of these components allows the components to operate at increasingly higher temperatures and/or with increased intervals between maintenance cycles.
The underlying components are typically designed to operate for extended periods in the structurally demanding high temperature and/or pressure environments. Superalloys such as Rene 80, Rene N4, and other nickel-based superalloys are commonly used in the underlying components. These superalloys may contain, by weight percent, 10 to 80 percent nickel, 5 to 22 percent chromium, up to 10 percent molybdenum, up to 5.5 percent titanium, up to 6.5 percent aluminum, up to 3 percent columbium, up to 9 percent tantalum, up to 15 percent tungsten, up to 2 percent hafnium, up to 1 percent rhenium, up to 1.5 percent vanadium, up to 40 percent cobalt, and up to 6 percent iron.
Ceramic matrix composites (CMCs) may also be selected for use in the underlying components Examples of commonly used CMCs include zirconia-based ceramics, alumina-based ceramics, magnesia-based ceramics, and ceramic composites such as alumina-silica (GE Gen 4), or a refractory material with, for example, silicon carbide, silicon nitride, alumina, silica, and/or calcia.
A suitable TBC applied to the underlying component should include one or more of the following characteristics: low emissivity or high reflectance for heat, particularly infrared heat having a wavelength of 0.5 to 60 micrometers; a smooth finish; and good adhesion to the underlying component. For example, thermal barrier coatings known in the art include metal oxides, such as zirconia (ZrO 2 ), partially or fully stabilized by yttria (Y 2 O 3 ), magnesia (MgO), or other noble metal oxides. The selected TBC may be deposited by conventional methods using air plasma spraying (APS), low pressure plasma spraying (LPPS), or a physical vapor deposition (PVD) technique, such as electron beam physical vapor deposition (EBPVD), which yields a strain-tolerant columnar grain structure. The selected TBC may also be applied using a combination of any of the preceding methods to form a tape which is subsequently transferred for application to the underlying substrate, as described, for example, in U.S. Pat. No. 6,165,600, assigned to the same assignee as the present invention.
The thermal barrier coatings described above have coefficients of thermal expansion that are significantly lower than the coefficients of thermal expansion of the underlying components. As a result, cyclic thermal stresses incident to repetitive heating and cooling of the system components disrupts the adhesion between the TBC and the underlying substrate, leading to spalling of the coating system.
A bond coat may be used between the TBC and the underlying substrate to improve the adhesion between the TBC and the underlying substrate. The bond coat may be formed from an oxidation-resistant diffusion coating such as a diffusion aluminide or platinum aluminide, or an oxidation-resistant alloy such as MCrAlY (where M is iron, cobalt and/or nickel). Aluminide coatings are distinguished from MCrAlY coatings, in that the former are intermetallics, while the latter are metallic solid solutions. U.S. Pat. No. 6,210,791, assigned to the same assignee as the present invention, describes one such bond coat applied between the TBC and the underlying substrate that substantially improves adhesion between the TBC and the underlying substrate. The bond described therein is an alumina and silica mixture in an alcohol solvent.
The thermal barrier coatings, with our without a bond coat to improve adhesion, typically require some type of post-application drying or heating at 500 to 2000 degrees Fahrenheit to sinter and/or stabilize the coating system. The application and post-application curing produces volatile organic compounds (VOCs) which may exceed current environmental, health, and safety limits for VOC emissions. To reduce VOC emissions during the application and post-application curing, the thickness of the TBC and/or bond coat may be reduced. However, the thinner TBC and/or bond coat results in a corresponding decrease in the thermal reflection of the thermal barrier.
Therefore, the need exists for an improved thermal coating system to protect system components from excessive heat. Ideally, the thermal coating system will have low emissivity or high reflectance for heat, particularly infrared heat having a wavelength of 0.5 to 60 micrometers. In addition, the thermal coating system should be able to be easily applied so as to produce a smooth finish surface that adheres to the underlying substrate component without producing excessive VOCs during the application or post-application curing.
BRIEF DESCRIPTION OF THE INVENTION
Aspects and advantages of the invention are set forth below in the following description, or may be obvious from the description, or may be learned through practice of the invention.
One embodiment of the present invention is a thermal coating system. The thermal coating system includes a substrate, a first coating layer applied to the substrate, and a second coating layer applied to the first coating layer. The substrate is selected from the group consisting of superalloys and ceramic matrix composites. The first coating layer comprises an alumina powder, a silica binder, and at least one additive selected from either a first group or a second group. The first group consists of toluene, zylene, cellosolve acetate, EE acetate, and mineral spirits. The second group consists of methyl ethyl ketone, methyl isobutyl ketone, lacquer thinner, and acetone. The second coating layer comprises at least one of zinc titanate or cerium oxide.
Another embodiment of the present invention is a method for applying a thermal coating system. The method includes applying a first charge to a bond coat mixture, wherein the bond coat mixture comprises an alumina powder, a silica binder, and at least one additive selected from either a first group or a second group. The first group consists of toluene, zylene, cellosolve acetate, EE acetate, and mineral spirits. The second group consists of methyl ethyl ketone, methyl isobutyl ketone, lacquer thinner, and acetone. The method further includes applying a second charge to a substrate, wherein the second charge has an opposite polarity of the first charge, and spraying the bond coat mixture onto the substrate. The method also includes applying a top coat mixture onto the bond coat mixture, wherein the top coat mixture comprises at least one of zinc titanate or cerium oxide.
A further embodiment of the present invention is a method for applying a thermal coating system that includes spraying a bond coat mixture onto a substrate using a liquid electrostatic sprayer. The bond coat mixture comprises an alumina powder, a silica binder, and at least one additive selected from either a first group or a second group. The first group consists of toluene, zylene, cellosolve acetate, EE acetate, and mineral spirits. The second group consists of methyl ethyl ketone, methyl isobutyl ketone, lacquer thinner, and acetone. The method further includes applying a top coat mixture onto the bond coat mixture, wherein the top coat mixture comprises at least one of zinc titanate or cerium oxide.
Those of ordinary skill in the art will better appreciate the features and aspects of such embodiments, and others, upon review of the specification.
BRIEF DESCRIPTION OF THE DRAWINGS
A full and enabling disclosure of the present invention, including the best mode thereof to one skilled in the art, is set forth more particularly in the remainder of the specification, including reference to the accompanying figures, in which:
FIG. 1 provides a cross-sectional view of one embodiment of a coating system within the scope of the present invention;
FIG. 2 illustrates liquid electrostatic spraying of a coating system within the scope of the present invention; and
FIG. 3 is a graph of the reflective performance of one embodiment of a thermal barrier coating system within the scope of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
Reference will now be made in detail to present embodiments of the invention, one or more examples of which are illustrated in the accompanying drawings. The detailed description uses numerical and letter designations to refer to features in the drawings. Like or similar designations in the drawings and description have been used to refer to like or similar parts of the invention.
Each example is provided by way of explanation of the invention, not limitation of the invention. In fact, it will be apparent to those skilled in the art that modifications and variations can be made in the present invention without departing from the scope or spirit thereof. For instance, features illustrated or described as part of one embodiment may be used on another embodiment to yield a still further embodiment. Thus, it is intended that the present invention covers such modifications and variations as come within the scope of the appended claims and their equivalents.
FIG. 1 shows a cross-sectional view of a thermal coating system 10 applied to a substrate 12 according to one embodiment of the present invention. In this particular embodiment, the thermal coating system 10 includes first and second coating layers referred to respectively as a bond coat mixture 14 and a top coat mixture 16 .
The substrate 12 may be any material composition suitable for use in a high temperature environment. For example, superalloys and ceramic matrix composites as previously described are frequently selected for use in high temperature environments because of their suitable strength, ductility, and other physical characteristics.
The first layer or bond coat mixture 14 is applied to the substrate 12 and provides tight adhesion between the substrate 12 and any additional layers. The bond coat mixture 14 may be a modification of the bond coat described in U.S. Pat. No. 6,210,791, the entirety of which is herein incorporated by reference for all purposes. As described therein, the bond coat mixture 14 may be metallic, non-metallic, or a combination thereof, depending on the underlying substrate, and may include alumina powder, such as aluminum oxide, with a silica binder. An evaporable solvent, typically ethanol or isopropyl alcohol, is added to the bond coat mixture 14 to achieve the desired consistency. A suitable thickness for the bond coat mixture 14 may be approximately 0.5 to 8 mils (0.0005-0.008 inches), depending on the method of application and design needs.
To reduce the amount of VOCs generated during the application and drying, the bond coat mixture 14 may be applied using liquid electrostatic spraying (LES) techniques. In LES applications, an electrical charge is applied to the material being deposited, and a ground or opposite electrical charge is applied to the substrate. The charged material is then sprayed onto the substrate, and the polar attraction between the charged material and the substrate results in an increased deposit efficiency of the material onto the substrate with significantly less overspray and waste. The increased deposit efficiency produces a more uniform coverage, allowing the application of thinner layers of the material to the substrate to provide the same or better performance. As a result, LES applications provide significant cost savings of materials compared to conventional application techniques. In addition, the thinner application of the materials results in lower VOC emissions during both the application and the subsequent curing.
The electrical conductivity of the bond coat mixture 14 may need to be adjusted to obtain a desired particle size that allows the use of LES and improves the deposit efficiency. Additives such as toluene, zylene, cellosolve acetate, EE acetate, and mineral spirits may be added to the bond coat mixture 14 to make the mixture less electrically conductive and prevent agglomeration of the bond coat mixture 14 during spraying. Conversely, additives such as methyl ethyl ketone (MEK), methyl isobutyl ketone (MIBK), lacquer thinner, and acetone may be added to the bond coat mixture 14 to make the mixture more electrically conductive.
FIG. 2 illustrates an application of the bond coat mixture 14 using LES. A powder spray gun 18 , such as a Nordson Kinetix air spray system sold by Nordson Corporation, Westlake, Ohio, includes a nozzle 20 with an electrode 22 . An opposite charge or ground 24 is applied to a substrate 26 . As the spray gun 18 propels the bond coat mixture 14 through the nozzle 20 , the electrode 22 applies an electrical charge to the bond coat mixture 14 . The charged bond coat mixture 14 flows to the oppositely charged or grounded substrate 26 where the polar attraction between the charged bond coat mixture 14 and substrate 26 deposits the bond coat mixture 14 uniformly on a surface 28 of the substrate 26 . The magnitude of the electrical potential between the charged bond coat mixture 14 and the oppositely charged substrate 26 may be adjusted to increase or decrease the deposition rate on the substrate surface 28 , depending on the desired thickness of the application.
The use of nano-sized particles as the constituent elements in the bond coat mixture 14 further improves the benefits of LES. For example, LES application of nano-sized particles having an average diameter of less than approximately 500 nanometers may readily achieve uniform thicknesses of the bond coat mixture 14 as low as approximately 0.5 mils (0.0005 inches). A thinner application of the bond coat mixture 14 produces several benefits. For example, a thinner bond coat mixture 14 will have a correspondingly smaller change in temperature across the bond coat mixture 14 , resulting in better adhesion to the substrate 26 . In addition, the nano-sized particles will produce a more tightly packed and dense layer that increases the resistance of the bond coat mixture 14 to erosion.
Referring back to FIG. 1 , the thinner application of the bond coat mixture 14 using LES may not adequately cover all imperfections 30 in the surface 32 of the substrate 12 . As a result, an additional undercoat layer (not shown) may be included between the bond coat mixture 14 and the substrate 12 . The undercoat layer may comprise the same bond coat as previously described in U.S. Pat. No. 6,210,791. That is, the undercoat layer may comprise an alcohol mixture of alumina powder, such as aluminum oxide, with a silica binder. The undercoat layer may be applied using conventional application techniques known in the art. For example, the undercoat layer may be applied as a slurry spray, using air plasma spraying (APS), low pressure plasma spraying (LPPS), or physical vapor deposition (PVD) techniques such as electron beam physical vapor deposition (EBPVD). If needed, the undercoat layer is applied to a thickness of approximately 1 to 8 mils (0.001-0.008 inches) to fill in any imperfections 30 in the surface 32 of the substrate 12 . For applications in which the substrate surface 32 is sufficiently smooth, the undercoat layer may be reduced in thickness or omitted entirely.
The top coat mixture 16 is located on top of the bond coat mixture 14 . The combination of the bond coat mixture 14 and top coat mixture 16 provides the desirable smooth, wear, and reflective characteristics of the thermal coating system 10 . Specifically, a smooth outermost surface of the thermal coating system 10 promotes improved aerodynamics across the surface which may be important in various applications. The surface roughness of the top coat mixture 16 is preferably less than approximately 60 micrometers Ra and potentially less than 20 micrometers Ra. In addition, the bond coat mixture 14 tightly adheres the top coat mixture 16 to the substrate 12 to resist wear or spalling even after numerous thermal cycles. Lastly, the top coat mixture 16 possesses the desired reflectance characteristics, particularly for infrared heat having a wavelength between 0.5 and 60 micrometers, to protect the substrate 12 from heat in a high temperature environment.
The top coat mixture 16 may be comprised of zinc titanate or cerium oxide to provide the desired heat reflectance characteristics of the thermal coating system 10 . Suitable substitutes that may also provide the desired heat reflectance characteristics include barium titanate, yttrium oxide, dysprosium oxide, erbium oxide, europium, lanthanum oxide, lutetium oxide, thorium oxide, tungsten oxide, barium stannate, and barium tungstate, many of which may be supplied by Nano-Tek Technologies, Ltd.
The top coat mixture 16 may be applied using conventional application techniques known in the art. For example, the top coat mixture 16 may be wetted and layered on top of the bond coat mixture 14 as a slurry spray, using air plasma spraying (APS), low pressure plasma spraying (LPPS), or physical vapor deposition (PVD) techniques such as electron beam physical vapor deposition (EBPVD). The thickness of the top coat mixture 16 depends on the desired heat reflectance and application method and typically ranges from approximately 1 to 10 mils (0.001-0.010 inches).
In particular embodiments of the present invention, the thermal coating system 10 may be applied to the substrate 12 using a tape process as described in U.S. Pat. No. 6,165,600 and assigned to the same assignee as the present invention. In this process, compositions of the bond coat mixture 14 and/or top coat mixture 16 and/or optional undercoat layer as described above may be cast on a tetrafluoroethylene sheet. After the solvent evaporates from the compositions, the dried compositions are removed from the tetrafluoroethylene sheet and transferred to the substrate 12 to form the thermal coating system 10 . Pressure may then be applied to the thermal coating system 10 to mechanically bond the thermal coating system 10 to the substrate 12 .
Regardless of the application method, whether directly onto the substrate 12 or using the tape process as previously described, the thermal coating system 10 may be heated or cured after application to the substrate 12 . An autoclave, oven, or similar device may be used to heat the thermal coating system 10 at a temperature of between 500 and 2,000 degrees Fahrenheit. The heat removes the binders and remaining solvent and sinters the thermal coating system layers 14 , 16 . The sintering forms both chemical and mechanical bonds both in the thermal coating system layers 14 , 16 and with the substrate 12 . Alumina in the substrate 12 mixes with the molten bond coat mixture 14 and raises the melting point of the thermal coating system 10 . The melting point of the resulting thermal coating system 10 may thus be increased from approximately 1,500 degrees Fahrenheit to approximately 1,950 degrees Fahrenheit or higher, depending upon the actual composition of the substrate 12 . The increased melting point of the thermal coating system 10 allows the substrate to be exposed to higher temperatures, which, for jet engine and gas turbine applications, typically produces increased thermodynamic efficiency.
The duration of the heating varies from approximately 30 minutes to several hours, depending on the composition of the substrate 12 , bond coat mixture 14 , and top coat mixture 16 . For example, FIG. 3 provides a graph of the reflective performance of one embodiment of a thermal barrier thermal coating system within the scope of the present invention. In this embodiment, the bond coat mixture 14 was cast on a tetrafluoroethylene sheet and transferred as a tape to the substrate 12 . The top coat mixture 16 was then sprayed onto the bond coat mixture 14 , and the combination was then heated at 1,650 degrees Fahrenheit for approximately 1 hour. The graph provided in FIG. 3 shows the resulting reflectance values for heat applied at various angles to the substrate.
It should be appreciated by those skilled in the art that modifications and variations can be made to the embodiments of the invention set forth herein without departing from the scope and spirit of the invention as set forth in the appended claims and their equivalents. | A thermal coating includes a substrate, a first coating layer, and a second coating layer. The substrate is selected from the group consisting of superalloys and ceramic matrix composites. The first coating layer comprises an alumina powder, a silica binder, and at least one additive selected from either a first group or a second group. The second coating layer comprises at least one of zinc titanate or cerium oxide. A method for applying a thermal coating system includes spraying a bond coat mixture onto a substrate using a liquid electrostatic sprayer. The bond coat mixture comprises an alumina powder, a silica binder, and at least one additive selected from either a first group or a second group. The method further includes applying a top coat mixture onto the bond coat mixture, wherein the top coat mixture comprises at least one of zinc titanate or cerium oxide. | 2 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a continuation of and claims the benefit of U.S. patent application Ser. No. 13/170,260, filed on Jun. 28, 2011, entitled “ATTRIBUTE CATEGORY ENHANCED SEARCH”, which in turn claims the benefit of U.S. Provisional Patent Application No. 61/359,043, filed on Jun. 28, 2010. The subject matter of the earlier filed applications are hereby incorporated by reference in their entirety.
FIELD OF THE INVENTION
To illustrate motivation for the invention let us consider a search process of a consumer product in online store. For example, we want to find a certain knife in online store of one of the major retailer such as Target. If we do not have precise or sufficient description of the knife we are looking for, the online search engine will return hundreds of items matching word “knife” (see FIG. 1A ) and leave us with no option but to scroll through description of all of these objects one by one through many pages. While this example is very specific it is not unique. Whatever information was entered by the user (e.g., us) into the search system, most likely we have not entered all the information we have about the knife we are looking for. Often it happens because we simply do not know how to describe what we know about the object, e.g., its shape, certain design style, combination of color, etc. Most of the time, even if we could, the system does not provide means for us to enter all that information, simply because designing a universal user interface is impossible. Thus there is a need for a system and method that utilizes somehow the additional information that has not been provided to the system.
The present invention describes a system, method and computer readable storage medium comprising instructions for searching an object. The search process in the invented system takes advantage of images or short descriptions associated with sets of objects, where the said sets of objects are constructed based on their attribute values. Specifically, this invention describes a simple and quick method for building a category tree for the objects among which the desired object is being searched. The invention is applicable to search of any items, and is illustrated with an example of various applications from the consumer product searches. The disclosed embodiments relate generally to electronic devices with one or more physical nodes, and more particularly, to search systems and methods.
BACKGROUND
Searching is a popular topic in the computing world. With users wanting and demanding faster application, increase in information processing speeds, more memory, and smarter computers, searching and a system's ability to return accurate results very quickly is viewed as an important aspect of the computer experience. Some of the recent patents try to address this problem. For example, in the U.S. Pat. No. 7,664,739 “Object search ui and dragging object results” an object navigation system, user interface, and method that facilitate faster and smoother navigation of objects are provided. The invented, the system can generate a plurality of objects that can be rendered on a display space that spans a single page in length, thereby mitigating the need to navigate through multiple pages. The objects can also be viewed in a film strip format that is infinitely scrollable. While such techniques undoubtedly make search process more convenient compared to page-by-page navigation through search results, they fail to address the crucial requirement of fast search speed. Another shortcoming of the above mentioned patent is the lack of ability of the invented system to automatically reduced search space based on digital representation of information provided by the user about the object the user wants to find.
Digital image based search was also addressed in the industry. For example, in the U.S. Pat. No. 7,565,139 “Image based search engine for mobile phone with cameras”, the inventors improve user's search experience by allowing him to take a digital photograph of an object, match it with an item in the remote database and provide full information about the object to the user. Key ideas facilitating the search process include doing the initial search on the mobile phone, so that database access overhead is minimized, and sending low resolution image to the server, so that less bandwidth is needed thus improving the response time of the application. Unfortunately this and other search related intentioned we examined do not provide an effective solution in case when exact image or description of the desired object is not available. Conventional search systems display or present search results in the form of a column or list to the user (e.g., see FIG. 1A ). This format can be problematic from the user experience point of view for several reasons. The list may span many (sometimes hundreds) pages. Therefore the process of examining search results quickly becomes cumbersome and time-consuming. The user examining search results page by page gets tired and may skip important information. Thus only the item located on the top of the list will get full attention of the user.
A typical example of search results for a consumer product on the internet is shown in FIG. 1A . For illustration purposes we use online product search tool of one of the major retail stores TRAGET. Search for a word “knife” on www.target.com returns a list of 585 items. The search can be refined by specifying more precisely the desired object, e.g. by entering “kitchen knife”, etc. The result however is still a rather long list of “matching objects”. As is seen in FIG. 1B , the user would have to examine upto 277 “kitchen knifes”. This situation is not uncommon for other widely available products such consumer electronics, a piece of furniture, bicycle, more recently even solar screen, etc. Therefore, a more efficient system and method is needed that can guide the consumer through the search process, that matches his visual expectation and leads quickly to the right object.
Thus, in this invention we address the problem of improving the effectiveness of finding a roughly described object in a large set of similar object. We illustrate the invention using example of search for a knife. It will be obvious from the description presented later in this disclosure that the system and method are applicable for search of any object.
SUMMARY
The following presents a simplified summary in order to provide a basic understanding of some aspects of the systems and/or methods discussed herein. This summary is not an extensive overview of the systems and/or methods discussed herein. It is not intended to identify key/critical elements or to delineate the scope of such systems and/or methods. Its sole purpose is to present some concepts in a simplified form as a prelude to the more detailed description that is presented later.
Main idea of the invention is based on enhancing search process by splitting all available objects (after some pre-selection) into categories and walking the user through the tree constructed from these categories and using shapes/images corresponding to groups of objects in the search domain.
The subject application relates to a system(s) and/or methodology that facilitate viewing and refining search results. In particular, the application involves an improved data representation, improved search method and enhanced navigation method that when taken together, provide a smoother and more efficient search experience for a user. Contrary to traditional user interface and navigation means, the results are not paginated across multiple pages. Rather, they are essentially maintained on a single page, whereby the length of the page can depend in part on the number of objects attributes grouped in categories (defined later). Thus, attribute categories can be scrolled through all at once mitigating the need to page over and over again to see more results. In some cases the invented method may require user scrolling through more than one page along the attribute category tree (defined later). In such cases a legend will be provided helping the user to navigate easily through the available steps in the search process. As will be seen from the detailed explanation below, the system and method improve user experience by reducing the complexity of otherwise lengthy search process.
Solution presented in this invention disclosure consists of a system that takes initial input describing the desired object (e.g., consumer product) form the user. Then the system retrieves all the objects (e.g., products) matching the entered search criteria, constructs a tree structure based on objects' detailed description, and guides the user through that tree so that the user finds the desired product in a much fewer steps than going through the original long list. Construction of the tree structure and walking through the tree is facilitated by the auxiliary images matching categories related to the objects, whenever it is possible. By visually matching each category with the associated picture, the user can quickly determine the right category of objects, thus narrowing the search space and finding the desired object quickly.
To the accomplishment of the foregoing and related ends, certain illustrative aspects of the invention are described herein in connection with the following description and the annexed drawings. These aspects are indicative, however, of but a few of the various ways in which the principles of the invention may be employed and the subject invention is intended to include all such aspects and their equivalents. Other advantages and novel features of the invention may become apparent from the following detailed description of the invention when considered in conjunction with the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1A is a snapshot from www.target.com online search results for “knifes”;
FIG. 1B is a snapshot from www.target.com online search results for “kitchen knifes”;
FIG. 2 illustrates a functional block diagram of a generally conventional computing device or personal computer that is suitable for analysis of data records in connection with the interactive display table, in accordance with the present invention;
FIG. 3A is an example of a flow chart illustrating the main steps of the invented method;
FIG. 3B is an example of a flow chart illustrating STEP 32 from FIG. 3A (retrieval of information from the database), in accordance with the present invention;
FIG. 3C is a schematic illustration of attribute category construction using predefined images and textual description, in accordance with the present invention;
FIG. 3D is a schematic illustration of attribute category construction using only predefined images, in accordance with the present invention;
FIG. 3E is an illustration of (part of) attribute category tree and the search tree legend, in accordance with the present invention;
FIG. 4 is an example of a flow chart illustrating attribute category tree construction in accordance with an embodiment of the present invention;
5 A depicts a table describing basic knife objects, in accordance with the present invention;
5 B depicts a table describing blade shape objects, in accordance with the present invention;
5 C depicts a table assigning relation between objects of tables shown in FIG. 5A and FIG. 5B , in accordance with the present invention;
FIG. 6A-FIG . 6 D examples of images representing shape categories;
FIG. 7A-7B blade length selection graphical interface.
The foregoing summary, as well as the following detailed description of certain embodiments of the present invention, will be better understood when read in conjunction with the appended drawings. The figures illustrate diagrams of the functional blocks of various embodiments. The functional blocks are not necessarily indicative of the division between hardware circuitry. Thus, for example, one or more of the functional blocks (e.g., processors or memories) may be implemented in a single piece of hardware (e.g., a general purpose signal processor or a block or random access memory, hard disk, or the like). Similarly, the programs may be stand alone programs, may be incorporated as subroutines in an operating system, may be functions in an installed imaging software package, and the like. It should be understood that the various embodiments are not limited to the arrangements and instrumentality shown in the drawings.
DETAILED DESCRIPTION OF THE INVENTION
Aspects of the present invention can be used in connection with a computing device including a touch screen. With reference to FIG. 2 , an exemplary system 1 suitable for implementing various portions of the present invention is shown. The system includes a general purpose computing device in the form of a conventional computer (PC) 12 , provided with a processing unit 112 , a system memory 118 , and a system bus 11 . The system bus couples various system components including the system memory to processing unit 112 and may be any of several types of bus structures, including a memory bus or memory controller, a peripheral bus, and a local bus using any of a variety of bus architectures. The system memory includes read only memory (ROM) and random access memory (RAM). A basic input/output system (BIOS), containing the basic routines that help to transfer information between elements within the PC 12 , such as during start up, is stored in ROM. The PC 12 further includes a hard disk drive 1161 for reading from and writing to a hard disk (not shown), an optical disk drive 1111 for reading from or writing to a removable optical disk, such as a compact disk-read only memory (CD-ROM) or other optical media. Hard disk drive 1161 and optical disk drive 1111 are connected to system bus 11 by a hard disk drive interface 116 and an optical disk drive interface 111 , respectively. The drives and their associated computer readable media provide nonvolatile storage of computer readable machine instructions, data structures, program modules, and other data for PC 12 . Although the exemplary environment described herein employs a hard disk and removable optical disk, it will be appreciated by those skilled in the art that other types of computer readable media, which can store data and machine instructions that are accessible by a computer, such as magnetic disks, magnetic cassettes, flash memory cards, digital video disks (DVDs), Bernoulli cartridges, RAMs, ROMs, and the like, may also be used in the exemplary operating environment.
A number of program modules may be stored on the hard disk, optical disk, ROM, or RAM, including an operating system, one or more application programs, other program modules, and program data. A user may enter commands and information via the PC 12 and provide control input through input devices, such as a keyboard 1151 or a pointing device 1152 . Pointing device 1152 may include a mouse, stylus, wireless remote control, or other pointer, but in connection with the present invention, such conventional pointing devices may be omitted, since the user can employ the touch sensitive interactive display for input and control. As used hereinafter, the term “mouse” is intended to encompass virtually any pointing device that is useful for controlling the position of a cursor on the screen. Other input devices (not shown) may include a microphone, joystick, haptic joystick, yoke, foot pedals, game pad, satellite dish, scanner, or the like. These and other input/output (I/O) devices are often connected to processing unit 112 through an I/O interface 115 that is coupled to the system bus 11 . The term I/O interface is intended to encompass each interface specifically used for a serial port, a parallel port, a game port, a keyboard port, and/or a universal serial bus (USB).
System bus 11 is also connected to a camera interface 119 . The digital video camera may be instead coupled to an appropriate serial I/O port, such as to a USB port. A monitor 1132 can be connected to system bus 11 via an appropriate interface, such as a video adapter 113 . The system also has a touch screen display 1131 which can provide richer experience for the user and interact with the user for input of information and control of software applications. The touch screen display 1131 is communicatively coupled to a touch sensor and controller 1133 . Touch sensor and controller can be combined in one block 1131 or they can be separate communicatively coupled blocks. It should be noted that the touch screen display 1131 and the touch screen sensor and controller 1133 can be enclosed into a single device as well. User interface can be implemented through the optional monitor 1132 coupled with the touch sensor and controller 1133 though the video adapter 113 or directly via internet, wireless, or another connection. It will be appreciated that PCs are often coupled to other peripheral output devices (not shown), such as speakers (through a sound card or other audio interface—not shown) and printers.
The present invention may be practiced on a single machine, although PC 12 can also operate in a networked environment using logical connections to one or more remote computers, such as a remote computer 1142 . Remote computer 1142 may be another PC, a server (which can be configured much like PC 12 ), a router, a network PC, a peer device, or a satellite or other common network node, and typically includes many or all of the elements described above in connection with PC 12 . The logical connection 13 depicted in FIG. 1B can be a local area network (LAN) or a wide area network (WAN). Such networking environments are common in offices, enterprise wide computer networks, intranets, and the Internet.
When used in a LAN networking environment, PC 12 is connected to a LAN through a network interface or adapter 114 . When used in a WAN networking environment, PC 12 typically includes a modem (not shown), or other means such as a cable modem, Digital Subscriber Line (DSL) interface, or an Integrated Service Digital Network (ISDN) interface for establishing communications over WAN, such as the Internet. The modem, which may be internal or external, is connected to the system bus 11 or coupled to the bus via I/O device interface 115 , i.e., through a serial port. In a networked environment, program modules, or portions thereof, used by PC 12 may be stored in the remote memory storage device. 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, such as wireless communication and wide band network links.
Conventional search systems display or present search results in the form of a column or list to the user. Example of such output of search results is shown in FIG. 1B . The list may span many pages. Hence the process of examining search results becomes cumbersome and time-consuming. The user examining search results page by page gets tired and may skip important information. Thus only the item located on the top of the list will get full attention of the user. Clearly, this is not the best user experience, for someone who wants to find the desired product quickly. This invention provides a smarter search solution, which takes however minimum information the user may have about the object he is trying to find, and guides him quickly to the searched object. The main steps of the invented method are illustrated in FIG. 3A below. Each of the steps shown in FIG. 3A is described in detail in the following paragraphs.
Step 31 : The system 1 takes the initial input describing the desired object (e.g., a consumer product such as knife) form the user via one or several user interfaces shown in FIG. 2 . Methods of entering information about the desired object include but are not limited to text or audio description, digital image input as a file or as a reference to picture on the internet. For example, regular description of the object can be entered as text through the keyboard 1151 and displayed in monitors 1132 or 1131 . The user may provide object description in the form of a picture taken by a digital camera or mobile phone and uploaded to the Processing unit 112 of the system through the camera interface 119 or USB interface 1171 . Audio description of the desired product can also be entered through the microphone 1176 connected to the audio-card 1175 and processed by speech recognition system.
Step 32 : Some information entered by the user (e.g., price range, warranty period, manufacturer, etc.) will be of the same type as columns in one or more the database tables, and could, therefore, be usable for constructing an SQL query. We will refer to such information as structured. However some information may not be easily translated into a structured query, but yet can be used by the user to navigate through the search process and find the desired product quickly. This will be illustrated below. Based on the structured input, software running on processor 112 of the system 1 will form a query to the database 1141 and retrieves information about all the objects (products) matching the entered search criteria. Original data can be stored in the database 1141 in various formats as explained in more detail in Appendix I below. A flow chart illustrating this procedure is shown in FIG. 3B . If no information matching the entered the criterion is returned, the system will prompt the user to change the entries in the input or reduced the entered information. Connection of the database 1141 can be implemented via communication link 1143 , which includes but is not limited to a wire-line connection (such as Ethernet), a wireless connection (Bluetooth, WiFi, etc.), or any other connection supporting information exchange between computing devices, and via the corresponding network interface 114 . Let's assume that based on the structured information the system is able to retrieve n objects described by m attributes.
In alternative embodiment of the invention, step 32 is omitted. In that case all information entered by the user is sent to the remote computer 1145 co-located with the database 1141 . Therefore without loss of generality in the continued description of the invention we can assume that all the information is non-structured. The idea behind the usage of non-structured information is to present the user with several (but limited) choices at each step, and proceed with the selection process for nodes of the category tree (see Step 33 below) according to user's understanding of the right selection done in each step by the user.
Step 33 : In this step the system constructs a tree based on attributes of available objects with the minimum level of nodes needed to complete the search process in pre-defined number of interactive search steps (described below) s. The first step is to divide all available objects into categories according to the values of each attribute. Schematic illustration of this step is provided in FIG. 3C .
Let n and m denote the number of objects and number of attributes describing each object, respectively. Assume an attribute A (e.g., attribute “Function” as shown in step 361 of FIG. 3C ) has t (1≦t≦m) distinct values (step 362 ). If k is the number of choices we want to be given to the user at each step of interactive search, then we can split the number of objects into k categories according to the values of the attribute A (step 363 ). Each category must have a unique graphical depiction and/or text indicating to the user the range of values of the attribute in that category. For example, in step 364 of FIG. 3C , consumer products were divided according to their function into several categories, one of which was depicted as a “set of plates” with textual description “plates” ( 365 ), and another depicted as a “knife” and described “knifes” ( 366 ). In another example shown in FIG. 3D , a similar procedure is repeated for an attribute “shape of blade” applicable to objects in “knifes” category. As is seen in step 374 in this case we select only graphical depiction of each category.
The process of dividing object into k categories depends on the nature of the attribute A, and can be done either at the time when information about an object is entered in a database or sometimes automatically, e.g., when attribute has a numerical value, as will be illustrated later. In the example shown in FIG. 3C (as well as in FIG. 3D ), the former method was used, and each object was linked to the pre-selected depiction and textual description as is illustrated by pointed arrows 367 , 368 , and 369 .
We use attribute categories described above to construct a tree. Each level of the tree is represented by attribute groups of corresponding to one attribute. As is shown in FIG. 3E , from the root 380 on the top we may start with “Function” attributes groups 381 , followed by “shape of blade” attribute related nodes 382 under “knifes” node, followed by “length of blade” (please see definition of this attribute below) related nodes 383 , etc. Notice that step 381 is equivalent to retrieving all object using a single search word “knife”, as it was done in the initial example illustrated in FIG. 1A . Of course, we do not see now description of individual objects. Instead we can select attribute categories most closely describing the knife we are looking for. If we assume that each attribute category has the same number of objects linked to it, then at each selection step, the number of available object in the search space will reduced by a factor of k. Please note that this assumption is natural for attributes with numerical values, since we can easily select numerical values appropriately. For example, after step 382 in FIG. 3E , the system can re-balance the remaining knifes with the selected shape into k sets of equal size as follows. Order the knifes with the selected shape by “length of blade” values and split them into k sets roughly the same size by putting k knifes with the shortest blades into the first category, put knifes with the next k shortest blades into the second category, etc. For the attributes without numerical values, such re-balancing is not possible, unless there is finer category division (e.g., one could have 10*k different shapes instead on k). Then smaller categories can be re-grouped in order to keep the category size more or less equal. Such process would require additional pre-configuration which may not be justified for many products due to unnecessary complexity. It would suffice to place such categories on top of the category tree as is shown in FIG. 3E above. Moreover, in the worst case all the objects would fall into a single category and other categories would be empty. In such case the user would either select the non-empty category which is equivalent to skipping one level of tree, or end the search by selecting an empty category. Hence, in the illustrated worst case we may have to add one extra level of the tree. This is possible whenever m>log k n (please see the next paragraph).
Therefore, if attribute values are distributed uniformly, it would take on the average log k n steps (i.e., levels of the tree) to complete the search. If the number of attributes m is higher than log k n, we have freedom to select the most suitable attributes for the tree construction. Suitable here means, attributes for which category division is straight forward and unambiguous, e.g., clearly distinctive images can be used for each category, and/or the attribute has numerical values, etc. Once the tree is constructed, the search can be made very fast. Specifically if there are n objects, and k is the number of distinct groups for each attribute, the estimated number of step s for search completion is ┌log k n┐. For example, if we allow 4 distinct attribute groups for each attribute, the maximum number s of search steps for a set of 585 objects (as in FIG. 1A ) is 5.
In case when the number of the tree levels (attribute category levels) can not fit on a single page, the system will provide a legend of attribute categories for the objects selected in step 381 . The purpose of this function is to allow the user to view all search tree levels at once, to go directly to the desired attribute category, and go back along the tree and try another branch, if necessary. For example, going back to FIG. 3E we see the legend 397 of all the levels of the search tree. Two level shown in window 385 are “Root” 390 and “Function” 391 . These levels are on top of the tree, and selecting a specific function is equivalent to running a single word search query such as “Knife”. As was illustrated earlier in FIG. 1A , such search could result in 585 matching objects. The system will construct attribute based category tree corresponding to all knifes. As was illustrated above, if each level of the tree has 4 nodes with evenly distributed objects among them, the user would have to make selections in 5 levels of the tree in order to complete the search. For example, these five levels could be “Shape of Blade” 392 , “Length of Blade” 393 , “Price” 394 , “Warranty Period” 396 , and “Handle Color” 397 . These five attributes are shown as part of the legend in window 386 . Since all of the levels of the tree may not fit on one page, as is shown in FIG. 3E , the user can use the legend to see all of them and to navigate through the levels of the tree. All levels that can be examined on the right hand side of the current page are highlighted in window 398 . The is always an active level—the level at which the user is expected to make next selection. Active level is underscored in the legend. For example, in FIG. 3E the active level is “Length of Blade” 393 .
The generic attribute category based tree construction method is illustrated by a flow chart in FIG. 4 in three main steps. Step 41 describes input to the tree construction algorithm. These are number n of objects, each object is described by m attributes as described earlier as well as in Appendix I. We also assume that we are given maximum number k of categories for each attribute (see previous paragraph). Step 42 describes category construction for each type of attributes. Non-numeric attributes such product images are mapped to one of the image categories by default. Each such category has an image representing it. For a numerical attribute j (e.g., price) we can identify range of the attribute values (in this case that would minimum and maximum price). The price range is split into k intervals each containing equal number of distinct price values. Then each price interval defines price category. It is obvious that user presented a choice of price category will be able to select the one which will guarantee that the number of choices does not exceed |S|/k, where |S| is the number of distinct price values. Step 42 is repeated for all m attributes. For example, later we illustrate “length of knife blade” as another category set. Finally in step 43 , tree nodes for which graphical depiction is available in the user input, are being placed on the top of the tree. Next levels of tree nodes are represented by categories of attributes with numeric values (e.g., price range, warranty period, length, weight, etc.) Categories of attributes with textual description are placed in the lowest levels of the tree. These attribute values are not easy to categorize and almost always the corresponding categories will be predefined. For example consider such attribute of a product as “manufacturer”. Most likely the user either will know exactly what value of such attribute he is looking for, in which case the selection is very simple, or he does not know, and at the end of the search process we will be left with a very few products to choose from, so that selection process can be completed quickly.
As stated earlier the purpose of the algorithm is to facilitate object search by the user, who has some (perhaps very limited) non-structured information about the object which has not been used yet. Each attribute A[j], 1≦j≦m, can take N[j] different values. We can assume that no two objects have the same attribute values. Therefore, n could be at most N[1]·N[2]· . . . ·N[m]. Examples of attributes for a product such as knife can be described A[1]=“shape of the blade”; A[2]=“length of blade”; A[3]=“quality of the material (e.g. steel that the blade is made of)”; A[4]=“handle color”, A[5]=“warranty period”; A[6]=“price” etc. Some attributes, such as “price”, “warranty period”, etc., have numeric values, others can be represented by images, e.g., “shape of the blade”. If the number of choices k at each step is predefined, for each attribute the set of distinct values is divided into k groups. For example, if k=4, then shapes of blades will be split into four categories. The system uses image representation of each object whenever possible. Each object in the database has a photo, and therefore all available photos can be grouped in categories. Example of such grouping is shown in FIG. 6A-D . We will refer to these images as shapes images of the corresponding categories shape-A, shape-B, shape-C, and shape-D. Whenever the user knows exact or approximate graphical depiction of the desired object (even if it has not been provided to the system by the user in Step 31 of FIG. 3A ), the user can use his knowledge to select one of the category shapes (see Step 37 , FIG. 3A ). For example, the system will show shapes shown in FIG. 6A-6D , and ask the user to select one closely matching the product he is looking for.
If the user has difficulty selecting any one of depicted categories, the system will present the user with an option to select all, which is equivalent to skipping the current level of the tree. Therefore, it is possible that a user that skips sufficient number of selection levels will end up with more than one individual objects to select from. However such possibility does not reduce the benefits of the design system and method. It simply means that some users may not have sufficient information about the product they are looking for.
Steps 37 : For illustration of this step, let us assume the system has determined with the help from the user that the shape of the knife the user wants is matching FIG. 6C , and the user has not specified length of the blade. In that case the system select the branch of the tree under selected shape option shown in FIG. 6C and expand the tree below that node (please see FIG. 3E ). Thus the system will present the user with available blade length choices. (Here we assume that blade length is one of the attributes describing knifes. This particular attribute example is used for illustrative purposes only. It can be easily extended to any other numerical attribute.) By default the original tree must have k or less length categories. Assume that originally the length attribute was grouped into k=4 categories, but after the selection of shape-C ( FIG. 6C ) it was determined that knifes of particular shape are available only in three length-categories shown in FIG. 7A : 2″-4″ length category depicted by icon 71 , 5″-7″ category shown as icon 72 , and 11″-12″ category shown by icon 73 . The user can select one of these three categories by pressing in any of the category icons, or he can use the sliding bar 74 and select the exact length by touching the button 75 and sliding it along the sliding bar 74 until the desired length value appears inside the button 75 . Then the user can select the knife with specified blade length by pressing the button 75 . According to one embodiment these functions will be performed by the user using touch screen interface available through touch screen display 1131 and touch screen sensor and controller 1133 shown in FIG. 2 . Alternatively, system can provide conventional graphical user interface where the user can slide and press button 75 using a pointing device 1152 such as mouse or touchpad device.
In one embodiment whenever a certain option is available the color of the sliding button 75 will be green. In cases when certain length options are not available, the color of the button will be clear or red, and/or the appropriate message will be displayed inside the button 75 . For example in FIG. 7B , the unavailability of a knife of length 9″ is shown. In another embodiment proper matching or availability of certain options will be communicated to the user via audio announcements. For example, the system may announce “You may select three blade length options”. Or alternatively, the system may say “selected blade shape of length 9″ is not available” if the user tries to select such option, etc.
Steps 38 - 39 : Similar approach can be used for any numerical attribute such as price range, warranty period, etc. In other words, the user does not have to specify all these attributes. The system will automatically guide the user through the available options, thus quickly narrowing the search space. The process will continue until all levels of three are passed and the desired product is found.
The preferred way of storing product information in a database is by using a hierarchical structure such as used in XML-like format. However, it is not necessary for this invention. In fact data can be stored in a series of flat tables as is a common practice in relation databases. A table here refers to a two dimensional representation of data using columns and rows. Each column represents an attribute, and each row is a tuple representing an object and information about that object. For example, knifes can be described in two or more basic tables describing knife and blade shape objects shown in FIG. 5A and FIG. 5B , respectively. These tables are in turn linked by another table associating knifes with the corresponding blade objects.
There are at least two ways to map tree structure to data stored flat tables and back. One method, called the adjacency list model, is based on recursive procedure applied to the table (adjacency list) mapping each node in the tree to its parent. This method is simple to implement, but due to recursive nature may take relatively long time to execute. The other method, called preorder tree traversal algorithm, is faster and is based on traversing the tree branch-by-branch from the left hand side (counterclockwise), and marking each node with the two step numbers corresponding to the steps on which the node is being visited. The latter method allows to assess quickly the number of descending nodes for each given node in the tree. If a node N has numbers l and r as left and right write markers, then the number of nodes below N is (r−l−1)/2. | Performing a user initiated search query is disclosed and comprises receiving user input comprising description details of at least one desired object, retrieving a plurality of objects from a database sharing one or more of the description details of the user input, constructing a tree data structure based on the description details of the plurality of objects, the tree data structure comprising one or more attributes related to each of the plurality of objects retrieved, displaying visual images associated with the retrieved plurality of objects, the visual images matching at least one of the attributes related to the plurality of objects, and receiving a user selection of one or more of the visual images. | 6 |
FIELD OF THE INVENTION
This invention relates to compositions including a bleaching agent. In particular, the invention relates to bleaching compositions provided in granule form for use in laundry, cleaning and as disinfection agents, as well as in textile treatment and wood, pulp and paper bleaching, for example. More particularly, the invention is related to methods of making co-granules of bleach activator/peroxide compounds and compositions made thereby, and especially, for example, bleach activator/percarbonate co-granules having good storage stability and improved bleaching performance in a broad variety of applications.
BACKGROUND OF THE INVENTION
Inorganic peroxide compounds, such as hydrogen peroxide, solid peroxides, which release hydrogen peroxide by dissolving in water (e.g. sodium perborate and sodium percarbonate perhydrate), have been used as oxidants for disinfection and bleaching for a long time. The oxidation properties of such compounds are strongly dependent on temperature. For example, hydrogen peroxide or perborate in alkaline bleaching liquors show satisfactory, accelerated bleach performance on soiled textiles only at temperatures above 80° C.
At lower temperatures, the efficiency of oxidation of an inorganic peroxide compound can be improved by addition of bleach activators. These bleach activators include N- or O-acyl compounds, e.g. multiple acylated alkylene diamines, especially tetra acetyl ethylene diamine and tetra acetyl glycoril, N-acylated hydantoines, hydrazines, triazoles, hydrotriazines, urazoles, di-keto piperazines, sulfurylamides, and cyanurates, as well as carboxylic acid anhydrides, especially phthalic acid anhydride and substituted maleic acid anhydrides, carboxylic acid esters, especially sodium-acetoxy-benzene sulfonate, sodium-benzoyloxy benzene sulfonate (BOBS), sodium-nonanoyloxy benzene sulfonate (NOBS), sodium-lauroyloxy-benzene sulfonate (LOBS), sodium-isononanoyloxy benzene sulfonate (Iso-NOBS) and acylated sugar derivatives, like pentaglucose. In the presence of such bleach activator substances, the bleach performance of aqueous peroxide solutions can be improved such that similar bleaching results are achieved at a temperature range of 40-50° C., comparable to those of sole peroxide solutions at 95° C. Mixtures of bleach activators may be used as well, which may include both hydrophilic and hydrophobic bleach activators. Mainly, hydrophobic components derivatives of the readily water soluble sodium-phenolsulfonates are used, e.g. nonanoyloxy benzene sulfonate, acetoxy benzene sulfonate or benzoyloxy benzene sulfonate. These hydrophobic compounds are preferably combined with tetra acetyl ethylene diamine. Also, bleach activators based on hydroxy benzoic acids and derivatives thereof show effective bleach performance.
Bleach activators in the form of granules are preferred as bleaching components in combination with substances generating hydrogen peroxide, e.g. sodium perborate or sodium percarbonate for use in laundry, cleaning, and disinfection applications, in textile and fiber treatment preparations, and in the wood, pulp and paper industries. In order to avoid the premature reaction of a bleach activator and peroxide compounds resulting in a loss of bleach performance, a number of processes have been developed to stabilize such systems by granulation, using binders and other additives and to eventually protect the granules by coating.
For example, EP 0 037 026 shows a process for the production of a readily dissoluble granulated activator containing 90% to 98% active matter. The bleach activator in powdered form is homogenously mixed with cellulose or starch ethers in powdered form, followed by spray-on of an aqueous solution of the cellulose or starch ether, followed by granulation processing and a drying step. Because of the gelling of the cellulose and starch ethers in water, causing poor flow properties and low adhesive power, the activator granules according to this reference are less than optimally stable.
In EP 1 447 380 A1, a process for the production of sodium percarbonate is shown. A hydrogen peroxide solution is sprayed onto sodium carbonate while simultaneously drying in an air current. This process yields granules having less than optimal solubility characteristics, especially at low washing temperatures, with resultant, less than optimal bleach performance.
U.S. Pat. No. 5,458,801 discloses a process for producing bleach activators comprising core granules of sodium percarbonate or sodium perborate. The activators are coated with borate, mixed in the presence of water-soluble binders and then granulated. The use of boronic compounds raises toxicological concerns, and therefore these are not preferred components in laundry and cleaning formulations. U.S. Pat. No. 5,458,801 teaches that a granulation process of percarbonate and bleach activators is only possible if the percarbonate is coated with borate.
There is a demand, therefore, for methods and compositions, that combine a bleach activator and bleach material in a form which is easy to produce and highly effective while providing long term shelf stability. The present invention satisfies the demand.
SUMMARY OF THE INVENTION
One aspect of the present invention provides a method for manufacturing bleach granules, containing at least one bleach activator and at least one bleach component (also referred to herein as peroxide component). To provide better bleach performance, the bleach activator and the peroxide components may be combined closely and formulated to have better storage stability and yet also be readily dissolvable.
In a preferred embodiment, a process for preparation of co-granules including at least one bleach activator and at least one peroxide compound, wherein the peroxide component is mixed and coated with a binder selected from the group of fatty acids, fatty acid polyol esters, polyglycols and fatty alcohol oxyalkylates, is disclosed. Bleach activator is added to this mixture, followed by agglomeration in a high-shear mixer, to provide co-granules including bleach activator and peroxide components.
In another preferred embodiment, the co-granules of bleach activator and peroxide components are produced by mixing the bleach activator with a binder selected from the group of fatty acids, fatty acid polyol ester, polyglycols and fatty alcohol oxyalkylates. A peroxide component is then added, followed by agglomeration in a high-shear mixer, yielding co-granules including bleach activator and peroxide components. If desired, the co-granules can be coated using standard coating materials and methods.
Therefore, preferred embodiments provide co-granules of a bleach activator and a peroxide component including one or more peroxide compounds, one or more bleach activators and at least one of a fatty acid, fatty acid polyol ester, polyglycol or fatty alcohol oxyalkylates.
In another embodiment, a process for the production of co-granules of one or more bleach activator and one or more peroxide component, including mixing and coating a peroxide component with one or more of a fatty acid, a fatty acid polyol ester, a polyglycol, and a fatty alcohol oxyalkylates, is disclosed. The bleach activator(s) is added in solid form. The resulting mixture is agglomerated in a high-shear mixer.
In yet another embodiment, mixing and coating a bleach activator with one or more of a fatty acid, a fatty acid polyol ester, a polyglycol, and/or a fatty alcohol oxyalkylates is disclosed. The peroxide component is added in a solid form. The resulting mixture is agglomerated in a high-shear mixer.
While the claims concluding the specification particularly point out and distinctly claim the precise subject matter regarded as invention, the preferred embodiments may be best understood from the following detailed description.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
The term bleach may be used in the contexts of both soil removal and whitening. For example, in common fabric and textile cleaning, bleach will react with and dissociate certain soils (i.e. tea, wine stains) thereby removing them from the surface of the fabric they are adhered to. Also, bleach, as an oxidizer, will break apart light absorbing chemical configurations called chromophores, rendering the oxidized material colorless.
Bleaching can also be applied to soil on hard surfaces. Additional potential applications are in personal care, e.g. bleaching hair, improving cleaning properties of denture cleaners, etc. Furthermore, the bleach compounds, or oxidizing compounds formulated according to the preferred embodiments herein, can be used in industrial cleaning applications, for bleaching wood, pulp and paper, for bleaching cotton, as well as for germ-killing formulations.
The preferred embodiments herein may also be used for cleaning textiles and hard surfaces, especially dishes, by using bleach activator compounds in combination with peroxygen components in an aqueous solution. These can contain additional materials for washing and cleaning hard surfaces, and more particularly, for cleaning dishes, for which use in an automatic dish washing application is preferred.
Preferred peroxide components include perborate-monohydrate, perborate-tetrahydrate, percarbonates, alkali persulphates, persilicates, and percitrates in which sodium is the preferred alkali metal, as well as hydrogen peroxide adducts of urea or amine oxides. Additionally or alternatively, peroxycarboxylic acids, e.g. dodecane di-peracid or phthalimido percarboxylic acids, can be used which can be substituted at the aromatic ring. Addition of small amounts, for example, less than one percent by weight, of stabilizers of the bleaching agents, like phosphonates, meta silicates, as well as manganese and magnesium salts, is contemplated by alternate embodiments.
The co-granules of the bleach activator and peroxide components may include fatty acids or fatty acid polyol esters. Fatty acids comprise linear or branched, saturated or unsaturated fatty acids having 6 to 30 C-atoms, and preferably 10 to 22 carbon atoms. Examples of fatty acids include but are not limited to capronic acid, caprylic acid, 2-ethyl-hexanoyic acid, palmitoleinic acid, stearic acid, isostearic acid, oleic acid, elaidinic acid, petroselinic acid, linolic acid, linoleic acid, elaeosterinic acid, arachinic acid gadoleinic acid, behenic acid, eurucaic acid, and dimers of unsaturated fatty acids. More preferable are fatty acid carbon chain fractions of coconut oil, palm oil or tallow, most preferably stearic acid.
In a further preferred embodiment, the co-granules of bleach activator and peroxide component comprise fatty acid poly esters. These esters can be produced by esterification of polyvalent alcohols with fatty acids. Especially preferred are stearic acid esters of pentaerythritol, and even more preferred are pentaerythritol distearate. Useful as polyvalent alcohols are glycol, benzene glycol, propylene glycol, butylene glycol, butane diol, methylpropane diol, pentylene glycol, iso-pentyl diol, neopentyl glycol, hexylene glycol, hexane diol, ethylhexane diol, diethylene glycol, methoxy diglycol, ethoxy diglycol, butoxy diglycol, dimethoxy diglycol, dipropylene glycol, glycerol, oligo glycerol, poly glycerol, four-valent alcohols, e.g. erythrose, threose, especially pentaerythritol, five-valent alcohols, e.g. arabitol, adonitol, xylitol, six-valent alcohols, e.g. sorbitol, mannitol, dulcitol, as well as saccharides, e.g. ribose, xylose, lyxose, altose, glucose, fructose, galactose, arabinose, mannose, gulose, idose, talose, and desoxy sugars, like Rhamnose and fructose, disaccharides, e.g. cane-sugar, trehalose, lactose, maltose, gentiobiose, melibiose, cellobiose, oligo and poly saccharides, e.g. cellotriose, cellotetrose, raffinose, acarbose, as well as starch and its components amylose, amylopektin, and dextrines, dextranes, Xanthanes, or cellulose. Suitable for esterification reactions are all linear or branched, saturated and/or unsaturated fatty acids having 6 to 30 C-atoms, preferably 10 to 22 carbon atoms, as mentioned above.
The fatty acid esters according to the preferred embodiments can also be obtained by transesterifiaction of fatty acid methylesters with polyvalent alcohols or fatty acid triglycerides. The carbon chain in fatty acid methylesters consists of 8 to 22 carbon atoms, being linear or branched, saturated or unsaturated. Examples are palmitic acid, stearic acid, lauric acid, linolic acid, linoleic acid, isostearic acid or oleic acid. Fatty acid triglycerides comprise all native animal or vegetable based oils, fats, and waxes, e.g. olive oil, rapeseed oil, palmkernel oil, sunflower oil, coconut oil, linseed oil, castor oil, soybean oil, also in their refined or hydrogenated forms.
Saccharide esters can be obtained in good yields by reaction of saccharides with activated fatty acid derivatives, e.g. fatty acid chlorides or anhydrides in the presence of an amine base, e.g. pyridine.
Polyglycerol esters are preferred, e.g. diglycerol-140 EO-tristearate, sorbitan fatty acid esters, e.g. sorbitan oleate, ethoxylated polyethylene glycol stearates, esters of dextrines having a degree of polymerization of 3 to 200, preferably 5 to 100, most preferably 10 to 50, especially fatty acid esters of dextrine palmitate esters, as well as disaccharide esters, especially esters of cellobiose, most preferably cellobiose palmitate esters, esters of pentaerythritol, PEG especially pentaerythritol stearic acid esters, most preferably pentaerythritol distearate.
In one preferred embodiment, the co-granules of bleach activator and peroxide component include effective amounts of:
a) tetraacetyl ethylene diamine (TAED) b) sodium percarbonate c) stearic acid and/or pentaerythritol distearate.
In another preferred embodiment, the co-granules of bleach activator and peroxide components include:
a) one or more bleach activators in ratios from 1 to 50 weight-%, preferably from 1 to 20 weight-%, most preferably from 5 to 10 weight-% b) one or more peroxide components in ratios from 50 to 99 weight-%, preferably from 75 to 99 weight-%, most preferably from 80 to 90 weight-% c) one or more fatty acid or fatty acid esters in ratios from 1 to 50 weight-%, preferably from 1 to 20 weight-%, most preferably from 5 to 10 weight-%.
Thus, the ratio of bleach activator to peroxide component may be in the range of 1:0.5 to 1:20 parts by weight, and preferably 1:1 to 1:5 parts by weight.
Furthermore, in another preferred embodiment, the co-granules of bleach activator and peroxide component comprise additional binders, additives, and carriers. The group of binders includes cellulose, starch, ethers and esters thereof, for example carboxymethyl cellulose (CMC), methyl cellulose (MC) or hydroxyethyl or hydroxypropyl cellulose (HEC, HPC) and the corresponding starch derivatives, and can also include film-forming polymers like polyacrylic acids and salts thereof. Preferred binders include anionic compounds in powder form, especially cumeme, xylene, toluene sulphonates, alkylethersulphates, alkylsulphates, α-olefin sulphonates and soaps. The amount of binder based on finished granule can range from about 1 to 45 weight-%, preferably from about 5 to 30 weight-%.
The co-granules of bleach activator-peroxygen compound are used in detergent formulations according to the invention in concentrations of about 0.1 to 15%, preferably about 1 to 8%. In prespotters or disinfectants, the concentration of the bleach activator compound up to about 50% can be applied.
Granulation of the bleach activator-peroxygen compounds can be performed in known mixing equipment, either in a batch process or a continuous process. Suitable mixing devices include plough shear mixers (Lödige KM types, Drais K-T types) as well as other highly effective mixing devices, e.g. Eirich, Schugi, Lödige CB-types, Drain K-TT types). All mixing processes producing satisfactory mixing efficacy can be utilized.
According to another embodiment, all of the components are mixed simultaneously. Alternatively, the peroxygen compound is preferably mixed with a molten binder and homogenized. In a second step, the bleach activator is added, and the composition is granulated in a high-speed mixer.
One preferred mixer for preparing these preferred compositions is a Littleford Day Horizontal Plow Mixer, a medium intensity mixer that creates a mechanically fluidized bed of material. The mixer includes a horizontal cylinder or drum with a central shaft from which mixing tools radiate. The mixing tools cover the entire surface of the drum, eliminating dead spots where product would be unmixed. The mechanically fluidized bed provides for rapid mixing, effective heat transfer for both cooling and heating, and incorporation of liquids onto the materials. Rapid, accurate mixing of dry components is easily accomplished due to the mixing tools moving the material from end to end in the drum. Liquids can be sprayed onto the fluidized material bed from as low as 0.5% to 50%, i.e., to a point where the material becomes a paste or has a dough-like consistency. Use of an optional jacket can provide heat input for reactions, drying, melting of material in a coating operation, or as means to make a paste such as hot melt adhesives. Cooling of the product can also be accomplished with the jacket.
The mixers can be equipped with high speed choppers, mounted in a back lower quadrant of the mixer. These choppers impart high shear to the material, allowing for dispersion of material and incorporation of viscous liquids that are hard to spray. The chopper blade configuration can be changed to increase or decrease the shear input as needed. The mixers can be built as pressure vessels and vacuum rated per the process needs.
Materials may be discharged from the mixer through a contour door or a valve mounted in the center of the mixer bottom. The discharge of materials from the mixer is normally quite rapid. Additional valves can be added to the discharge door or valve to control the output flow therethrough for packaging, for example.
The residence time in the granulator is preferably 0.5 seconds to 20 minutes, and more preferably about 2 minutes to 10 minutes. In another preferred process option, a drying and/or cooling step is employed after granulation, to reduce or avoid stickiness of the granules produced. Post-treatment processes may be performed in the same mixer types described above or in conventional fluidized bed equipment. Coarse and fine particles may be separated by sieving. The coarse fraction may be milled and fed back into the granulation process together with the fines fraction.
Furthermore, in another preferred embodiment, the peroxygen compound, fatty acid or poly ester (binder), and optionally other solid, liquid or molten additives are fed into the mixing device and are homogenized. The mixture is heated to temperatures above the melting point of the binder. The bleach activator is added to this mixture to obtain a plastified mass. Mixing devices as mentioned above can be used, but also kneaders or specific extruder types (e.g. Extrud-o-mix of Hosokawa-Bepex Corp.) are suitable. The mass from the granulation step can be processed into extrudates by appropriate equipments, as extruder-types (e.g. single-screw and twin-screw, dome and basket extruders), a flat die press or a ring die press. Such equipment is available from companies such as Schlüter, Amandus-Kahl, Hosokawa Bepex, Fuji-Paudal or Händle. The extrudates are sized to the desired dimension in a post-treatment step. Optionally a spheronizer can be used for bead making.
After sizing of the granules, residual water can be removed to increase particle stability. Drying and/or cooling can be performed using the same mixer types described above, or in conventional fluidized bed equipment. Coarse and fine particles may be separated by sieving. The coarse fraction may be milled and fed back into the granulation process together with the fines fraction.
Coating
The granules can be directly used in laundry and cleaning products. However, in a more preferred form, a coating is be applied. Through coating, using film forming substances, the product properties can be influenced significantly.
Suitable coating materials include waxes, silicones, fatty acids, fatty alcohols, soaps, anionic surfactants, nonionic surfactants, cationic surfactants, anionic and cationic polymers, and polyalkylene glycols. Coating materials having a melting point in the range of 30 to 100° C. are preferred, e.g. C8-C31 fatty acids (e.g. lauric, myristinic, or stearic acid), C8-C31 fatty alcohols, polyalkylene glycols having a molecular weight of 1000 to 50000 g/mol, fatty alcohol oxyalkylates containing 1 to 100 moles of EO, alkane sulfonates, alkyl benzene sulfonates, α-olefins sulfonates, alkyl sulfates, alkyl ether sulfates, polymers (e.g. polyvinyl alcohols), and waxes (e.g. montane waxes, paraffin waxes, ester waxes, polyolefin waxes, silicones).
The coating materials can contain other materials either dissolved or suspended, like homo, co, or crafted co-polymers of unsaturated carboxylic acids and/or sulfonic acids, as well as alkali salts thereof, cellulose ethers, starch, starch ethers, polyvinyl pyrrolidone, mono and polyvalent carboxylic acids, hydroxy carboxylic acids or ether carboxylic acids having 3 to 8 carbon atoms, as well as salts thereof, silicates, carbonates, bicarbonates, sulfates, phosphates, and phosphonates. Depending on the desired properties, the coating material can be applied from 1 to 30 weight-percent, preferably 5 to 15 weight-% of the total coated granule. For coating, conventional mixers and fluidized bed devices can be used. Suitable mixers include, e.g. plough-shear mixers or Schugi Mixers.
The bleach activator-peroxygen compound-co-granulates according to the preferred embodiments described above can be used in laundry and cleaning products, as well as products used to kill germs. Major components of those consumer products include anionic surfactants, nonionic surfactants, builder systems (such as zeolites, phosphates, polymers, sodium carbonate, silicates and layered silicates), organic builders, enzymes, anti-redeposition agents (such as soil release polymers and dye transfer inhibitors), and other ingredients as known in the art, such as colors and fragrances, etc.
METHOD EXAMPLES
Two exemplary processes are provided hereinbelow to illustrate the manufacture of the bleach/bleach activator co-granule according to the invention.
1.) Sodium Percarbonate is charged to the mixing vessel along with the formulation amount of fatty acid. The mixer used is a Littleford Day MGT Series Vertical mixer/granulator with medium intensity vortex mixing using a single, four blade impeller located at the base of the mixer. The mix is heated to a temperature above the melting point of the fatty acid. The impeller RPM is raised to 1500 RPM. After 2 minutes of mixing, the mixer is stopped and the formulation amount of TAED is added. The mixing then continues for 30 seconds at a mixer speed of 1200 RPM. The mixing is then stopped and the batch is discharged. 2.) In a separate vessel, melt the fatty acid, add the formulation amount of TAED to the molten fatty acid. Charge the same mixer described in item #1 above with the formulation amount of sodium percarbonate and mix at a speed of 1200 RPM. After 1 minute stop mixing, add the molten mix of fatty acid and TAED to the sodium percarbonate, start the mixer and mix for 1 minute at a mixer speed of 1200 RPM. After 1 minute of mixing, discharge the mixer.
The formulation amounts used in both examples were:
Raw Material
wt. %
Sodium Percarbonate
83
TAED
10
Fatty Acid
7
Total
100
The mixers used were Lodige type, high speed mixers designed for efficient liquid dispersion on powders, and better control on product density and particle size distribution.
Table I shows median particle size for the tests conducted on the material made in the above examples. Data regarding median particle size (d50) was obtained using the ISO 3118 method.
TABLE I
Trial #
d 10 (mic.)
d50 (mic.)
d90 (mic.)
1
354
604
1070
2
326
577
966
3
309
580
987
Table II shows available oxygen, median particle size and stability data in a set of six different co-granulations made according to the invention. Data reflecting available oxygen is generated using “a standard potassium permanganate titration method.” Data reflecting median particle size is obtained using the ISO 3118 standard industrial method. Data reflecting stability percentage is obtained by measuring the remaining amount of available oxygen in the product (as a percentage of the original amount) after accelerated storage at industry standard test conditions.
TABLE II
Wt. %
Median
Wt. %
Wt. %
Fatty Acid
Wt. %
Particle
Trial
Sodium
Stearic
Polyol
Wt. %
Available
Size d50
Stability
#
Percarbonate
Acid
Ester
TAED
Oxygen
(microns)
(%)
1
83
8
9
10.7
604
84
2
84
7
9
11.1
577
94
3
84
7
9
10.1
685
71
4
83
8
9
10.2
596
82
5
89
2.5
8.5
12.0
589
70
6
83
8
9
9.4
700
96
The described embodiments are to be considered in all respects only as illustrative and not restrictive, and the scope of the invention is, therefore, indicated by the appended claims rather than by the foregoing description. Those of skill in the art will recognize changes, substitutions and other modifications that will nonetheless come within the scope of the invention and range of the claims. | A process for preparation of co-granules including one or more bleach activators and one or more bleach agent compounds is described. The bleach component is mixed and coated with a binder selected from the group of fatty acids, fatty acid polyol esters, polyglycols and fatty alcohol oxalkylates. One or more bleach activators is added to this mixture followed by granulation or agglomeration in a mixer, resulting in a bleach co-granule composition including the bleach activator and peroxide components. | 2 |
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of U.S. patent application Ser. No. 10/409,014, filed Apr. 8, 2003, which is a continuation of U.S. patent application Ser. No. 09/683,516, filed Jan. 11, 2002, now abandoned, which claims the benefit of U.S. Provisional Patent Application Ser. No. 60/319,011 filed Nov. 25, 2001.
1. BACKGROUND OF INVENTION
[0002] a. Field of the Invention
[0003] The present invention relates generally to audio and video distribution systems, and more particularly, to an audio/video distribution system that is configured to connect audio and video sources to video users without the need for a centralized switching and distribution apparatus.
[0004] b. Description of the Prior Art
[0005] It is often necessary to connect, switch, and properly route audio and video signals from sources, such as video cameras with audio capabilities and video tape recorders, for example, to end users over an extended area. The need for such switching capabilities exists in a wide variety of applications including television and video production, surveillance systems, home entertainment systems, and a myriad of other applications where audio and video signals must be connected and properly routed.
[0006] In the past, this connection has been performed with centralized switching arrangements. Such switching arrangements typically utilize a switching matrix that has audio/video inputs, audio/video output, and a manual or automated arrangement for connecting the inputs to the outputs.
[0007] Existing systems focus primarily on providing centralized video switching arrangements. For example, U.S. Pat. No. RE34,611, issued to Fenwick et al, discloses a system wherein video programs are transmitted to independently controlled video monitors via a centralized switching matrix. U.S. Pat. No. 6,160,455, issued to Hayashi et al., describes the switching of video programs using a computer local area network for the program setup and selection, and utilizes a centralized video distributor and routing switcher to distribute the audio/video signals. U.S. Pat. No. 5,889,775, issued to Sawicz et al., describes an entertainment server connected to video distribution boxes through the use of one or more crosspoint (centralized) switches. U.S. Pat. No. 6,104,414, issued to Odryna et al., describes an improved digital centralized switching matrix. U.S. Pat. No. 6,160,455, issued to Hayashi et al., describes the switching of video programs using a computer local area network for the program setup and selection, and utilizes a centralized video distributor and routing switcher to distribute the audio/video signals. U.S. Pat. No. 5,889,775, issued to Sawicz et al., describes an entertainment server connected to video distribution boxes through the use of one or more cross point (centralized) switches. U.S. Pat. No. 6,104,414, issued to Odryna et al., describes an improved digital centralized video distribution hub that utilizes a switching matrix. U.S. Pat. No. 5,455,619, issued to Truckenmiller et al., describes a video distribution system designed to distribute specific video programs to rooms (a hotel/motel type of lodging arrangement) using electronic tags, a computerized switching arrangement, and a centralized video distribution point.
[0008] Although a variety of attempts have been made to improve centralized audio/video switching arrangements, a number of shortcomings and distinct disadvantages still exist in such systems. Initially, it is seen that existing audio/video distribution systems require that the audio/video signal from each source be routed over a single cable path back to the centralized switching arrangement. As such, a single cable path must then be utilized to send the audio/video signals from the switching arrangement to the user of the audio/video signal. This results, unfortunately, in a complex and often times, cumbersome, plurality of cables required to convey these audio/video signals. If the audio/video sources and users are in close proximity to each other, this plurality of cables can potentially become quite difficult to manage. On the other hand, however, the plurality of cables are very difficult to manage and very costly to install and maintain in instances where the audio/video sources and users are not in close proximity to each other, as in the case of a building video surveillance system, for example.
[0009] Additionally, once the audio/video sources are in place, moving them to a new location requires installing new cables and identifying new electrical power sources for them. This results in an inflexible and expensive system that is inefficient, cumbersome, and difficult to install, maintain, and upgrade.
[0010] The general concept of a distributed audio/video switching system has been implemented in cable television systems in the form of distributed switching. Cable television uses a form of distributed switching, whereby different audio/video sources are frequency multiplexed onto the cable. This is accomplished by mixing the baseband audio/video signal with a carrier frequency in a non-linear manner. This causes the baseband audio/video signal to be frequency shifted to a higher-frequency band (or channel) and is accomplished by utilizing a transmitter. By using different carrier frequencies, multiple audio/video signals can be placed on the cable and “stacked” in frequency. To select an audio/video source, a receiver is then tuned to the proper carrier frequency. A number of existing systems utilize this principle to do audio/video switching. For example, U.S. Pat. No. 5,592,482, issued to Abraham, uses frequency multiplexing to distribute multiple video sources to multiple video users. Similarly, U.S. Pat. No. 5,767,894, issued to Fuller et al., discloses a system using a RF (frequency multiplexed) video distribution system to send video information from the video servers to the room TV sets. In this patent, the video distributions system may optionally include a plurality of coaxial cables or optical fibers (using a centralized switching arrangement). U.S. Pat. No. 5,818,512, issued to Fuller also uses a frequency multiplexed switching arrangement.
[0011] Although frequency multiplexing solves some of the cable management and cost issues of the centralized switching arrangements, it also has a number of shortcomings and disadvantages that have not been addressed. Naturally, the high cost of existing frequency multiplexing systems is of substantial concern. A very stable carrier frequency source and multiplex transmitter is required for each video source. The carrier frequency must be very stable because if it changes, the audio/video signal transmitted can interfere with an audio/video signal on an adjacent channel. In a surveillance application, where video sources may be in outside locations, the transmitter will be subject to inclement weather conditions and the stability of the carrier frequency can be influenced by external conditions such as temperature and humidity. Also, the transmitter itself is costly and complex, and can result in a variety of maintenance problems. Furthermore, such systems are one-way systems and it is not possible to control a specific video source. The audio/video sources all transmit on their specific channels, and it is up to the audio/video user to decide which source to use. This increases the cost and complexity of the receiving equipment, which must decode the particular channel of interest.
[0012] Another existing way to accomplish audio/video distribution is to store the audio/video information on computer disk, and send this information over a computer bus or local area network to another computer, which then decodes the digital audio/video to analog audio/video and sends it to a display to be seen. This type of distribution is described in U.S. Pat. No. 6,133,908 issued to Sciobra et al. This system is not a real-time system, where live audio/video from sources is displayed as live audio/video to users. Also, having processors to encode audio/video to digital and then decode the audio/video so that it may be displayed is extremely costly and trouble-prone. Furthermore, transmitting digital audio/video over long distances requires special networking technology that is difficult to manage and costly to install and maintain.
[0013] A number of other cable distribution systems have been developed by utilizing Ethernet and SCSI (Small Computer System Interface) technology. The information that flows over the cable is digital. This is disclosed in U.S. Pat. No. 5,550,584 issued to Yamada. Although such systems use digital signals to control the respective transmitters and receivers on the cable, the actual information (the audio/video information) is stored in analog form and must be converted to digital to send over these cables. Unfortunately, these systems are fully digital systems relying on complex protocols to coordinate the devices connected to the cable as well as complex transmitters and receivers used to send and receive the audio/video information. An illustration of a fully digital distribution system in accordance with the prior art is shown in FIG. 9 . FIG. 9 illustrates two video sources (VS 1 and VS 2 ) sending video into a single monitoring station. An analog video signal VS 1 320 is sent from a Video Source 42 into a device 350 that converts the analog signal into a sampled digital representation 333 . This is usually called an A/D device or a frame grabber (since it digitizes an entire video frame at a time) and produces a pixilated frame 334 (because the video frame is now broken up into picture elements (or pixels), with a resolution (pixels/inch) specified by the A/D device 350 . The greater the video resolution, the larger number of pixels would exist in the pixilated frame. For example, if the desired resolution were 480 pixels wide by 320 pixels high (a typical low-medium resolution image, such as used on digital cell phones that capture video), the pixilated frame would consist of 153,600 pixels. If 3 bytes of data are used for each pixel (1 byte for red, 1 byte for green, 1 byte for blue-the basic primary colors), the size of the pixilated frame in bytes would be 1,228,800 bytes. This frame is stored in a frame buffer 352 . A general-purpose digital computer composed of a CPU 351 , memory 353 , and a network interface 354 controls the acceptance and storing of the pixilated frame. It also controls the movement of the pixilated frame into the network interface, and well as provide network coordination and control of the pixilated image transmission to the monitor. If compression is used, this digital computer also performs the compression. Without compression, the data rates become very large. The standard real-time video frame rate is 1 frame every 1/15 of a second (NTSC standard). This means that a data rate of approximately 25 megabytes/second (including 35% data communications protocol overhead) must be sustained through the digital computer. Breaking that into bits/second (the standard measure for network data traffic, the data traffic rate across the network of approximately 200 megabits per second would be realized. This can be reduced by digital video compression, but a cost of significantly increased computer size (and power consumption) and significant delays in performing the compression. The digital transmission packets 342 from the VS 1 network interface 354 are shown. Transmitter VS 2 is similar to Transmitter VS 1 , with its VS 2 frame 326 being sent into the A/D 350 from the video source 42 . 336 , 337 , and 344 are the digitized video, the pixilated frame, and the digital data packet from video source VS 2 326 . These digital data packets 342 and 344 are received by a general-purpose digital computer located in the monitoring station. This general-purpose computer is composed of similar elements 354 , 352 , 353 , and 351 to the transmitters. The difference here is a D/A or video device 370 that converts pixilated video frames 334 into sampled frames, reconstitutes the sampled video into continuous video, and sends the video frames to a plurality of video users 48 . 330 is the continuous video for VS 1 , and 332 is the continuous video for VS 2 . Continuous video is required to display correctly on a video monitor. A comparison of a digital distribution system to the present invention is summarized in Appendix A.
[0014] Another cable-oriented distributed switched component audio/video system is disclosed in U.S. Pat. No. 4,581,645 issued to Beyers, Jr. This system is mainly an interconnection system for an audio and video component entertainment system. As such, the cable and its electronic components are designed for short distances where distributed computer control is not a factor. This system is not intended for audio/video sources and users over an extended geographic area, such as a large room, multiple rooms, or building where the control, audio, video, and power must be kept to a single continuous cable.
[0015] In all video systems synchronization signals are required. Specifically, a vertical synchronization signal delineates the start of a video frame, and a horizontal synchronization signal delineates the start of a horizontal line within the video frame. These signals may be produced in one of two ways. The first way, referred to as “self synchronization, is that each video source generates a synchronization signal these signals and embeds the synchronization signals with the transmitted video signal. The second way, referred to as “central synchronization” involves the use of a centralized synchronization source that generates signals to be fed to all transmitters and receivers in the system. One disadvantage with central synchronized systems is that the transmitters are far more costly than transmitters used in “self synchronized” systems. In addition, with all transmitters relying on synchronization signals generated by a central source, those transmitters that are remotely located experience time delays in receiving synchronization signals generated from a central generator resulting in synchronization problems unless the system is provided with electronic compensation resulting in higher cost and increased maintenance.
[0016] Accordingly, there is an established need in the art for a distributed audio/video system that is cost effective, highly flexible, and capable of being used over an extended area
SUMMARY OF INVENTION
[0017] The present invention is directed to a low cost, highly flexible audio/video distribution system configured to connect audio and video sources to audio and video users without the need for a centralized switching and distribution mechanism.
[0018] The term “audio/video” as used herein means audio or video or a combination of audio and video. Accordingly, any reference to audio/video should be understood to refer to audio only, video only, or a combination of audio and video.
[0019] The term “central synchronization” or “central synchronized” as used herein means the use of an external master synchronization generator which generates video synchronization signals that are common to all connected transmitters and receivers connected to the bus cable.
[0020] The term “self synchronization” or “self “synchronized” as used herein means that each transmitter generates its own synchronization signal.
[0021] An object of the present invention is to provide an audio/video distribution system that offers a substantially low-cost solution to connecting audio/video sources and users. This is accomplished using multiplexed analog video and audio and a simple control system.
[0022] A further object of the present invention is to provide an audio/video distribution system wherein the audio/video transmitters that place the audio/video sources onto the cable are relatively simple and inexpensive to manufacture and maintain.
[0023] Another object of the present invention is to provide an audio/video distribution system wherein the audio/video receivers extracting audio/video signals from the cable are also simple and inexpensive to manufacture and maintain.
[0024] An additional object of the present invention is to provide an audio/video distribution system utilizing control circuitry with low speed digital components in a cost-effective manner.
[0025] Yet another object of the present invention is to provide an audio/video distribution system that eliminates the need to have individual cables connecting users and sources back to a centralized switch.
[0026] A further object of the present invention is to provide an audio/video distribution system wherein the cable is a single cable assembly that is routed along a path common to the video sources and users.
[0027] In accordance with a first aspect of the invention, an audio/video distribution system is provided including a distribution cable, at least two audio/video transmitters, at least one receiver, and a control signal generator. The transmitter is configured to receive analog signals from at least one audio/video source and place these signals on the cable, while the receiver is connected to the distribution cable and configured to receive the analog signals from the distribution cable. The control signal generator is connected to the distribution cable and configured to control the transmitters and receiver.
[0028] These and other objects, features, and advantages of the present invention will become more readily apparent from the attached drawings and the detailed description of the preferred embodiments, which follow.
BRIEF DESCRIPTION OF DRAWINGS
[0029] The preferred embodiments of the invention will hereinafter be described in conjunction with the appended drawings provided to illustrate and not to limit the invention, where like designations denote like elements, and in which:
[0030] FIG. 1 is an illustrative schematic view showing a preferred embodiment of the overall layout of the present invention;
[0031] FIG. 2A is an illustrative schematic view showing a preferred embodiment of a battery powered power module of the present inventions;
[0032] FIG. 2B is an illustrative schematic view showing a preferred embodiment of an AC utility power module of the present invention;
[0033] FIG. 3 is an illustrative schematic view showing a preferred embodiment of the transmitter of the present invention;
[0034] FIG. 4 is an illustrative schematic view showing a preferred embodiment of the receiver of the present invention
[0035] FIG. 5 is an illustrative schematic view showing a preferred embodiment of the control signal generator of the present invention;
[0036] FIG. 6 is an illustrative schematic view showing a preferred embodiment of the cable status monitor of the present invention;
[0037] FIG. 7 is an illustrative schematic view showing a preferred embodiment of the cable extender of the present invention;
[0038] FIG. 8 illustrates a simplified operation of the present invention; and
[0039] FIG. 9 illustrates prior art-a digital distribution system.
[0040] Like reference numerals refer to like parts throughout the several views of the drawings.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0041] Shown throughout the figures, the present invention is generally directed towards a low cost, highly flexible audio/video distribution system configured to connect audio and video sources to audio and video users without the need for a centralized switching and distribution mechanism.
[0042] Referring primarily to FIG. 1 , the overall system layout for the audio/video distribution system is shown. In the preferred embodiment of the present invention, a cable 30 is utilized as shown. The cable 30 is a passive media that may be composed in any of a wide variety of configurations. Preferably, the cable 30 will be a combination of a plurality of electrical cables or optical fiber that provides a transmission media for the audio/video, control, power, and video synchronization signals that comprise the system. The cable 30 may be terminated, if desired, at each end using the appropriate terminators 36 to match the characteristic impedance (electrical or optical) of the cable 30 . As such, it is seen that the terminators 36 can be used to stabilize the signals on the cable 30 .
[0043] Transmitter 40 and receiver 46 have unique binary addresses. Signals from the control signal generator 44 (and programmed by the programming sequencer 54 ) are sent to each transmitter 40 or receiver 46 through the cable 30 to control certain properties of them. One specific property of the transmitter 40 is the ability to connect or disconnect its audio/video source to the cable. Each transmitter 40 has one of two states with respect to the cable 30 : connected or disconnected. When a transmitter 40 is in the disconnected state, it represents an electrically activated non-interfering mode to the cable 30 , and not physical disconnection, as in the case of a relay or an accidental unplugging of the transmitter 40 from the cable 30 , for example. When the transmitter 40 is in the connected state, it has the ability to send audio/video signals to the cable 30 so that they may be sent to other devices connected to the cable 30 . In this case, the connection consists of an electrically activated connection and not a physical connection. A variety of other states may also be controlled in the transmitter 40 and will be described later in this section. In the most preferred embodiment, however, only one transmitter 40 may be connected to the cable 30 at any given time.
[0044] When a transmitter 40 is connected to the cable 30 , the analog audio/video signals from the transmitter 40 are sent to all components connected to the cable 30 . Preferably, any receiver 46 that is connected to the cable 30 will have the ability to receive this audio/video signal. The control information, as sent by the control signal generator 44 , can control states within the receiver 40 , as will be described later. The transmitter 40 and receiver 46 may also contain circuitry that will take signals from the control signal generator and control auxiliary devices connected to the transmitter 40 and receiver 46 .
[0045] The control signal generator 44 sends signals to each transmitter 40 to connect it to the cable 30 for some period of time so that a receiver 46 may receive its audio/video signals. Signals are then sent to the control signal generator 44 to disconnect it from the cable 30 so that another transmitter 40 may connect to the cable 30 . The effect of this is to display the audio/video information from each audio/video source 42 in some programmed fashion to an activated audio/video receiver 46 . An illustrative example of this would be a video surveillance with 3 video cameras (with audio) and their associated transmitters 40 located at strategic points around a building. A monitoring facility is located somewhere inside the building. This monitoring facility contains a video monitor (with audio) and a video tape recorder. These two devices (the video monitor and video tape recorder) are connected to receivers 46 . These transmitters 40 and receivers 46 are connected to a common audio/video cable 30 . A control signal generator 44 is also located in the monitoring facility. The control signal generator 44 may either be programmed (or manually operated) to switch the video cameras so that they may cause their analog audio/video information to be sent to the video monitor and video tape recorder.
[0046] All the components connected to the cable 30 , including the audio/video sources 42 , may obtain their electrical power from the cable 30 . This is supplied to the cable 30 through a power module 34 that is connected to an external power source 32 . Thus, in the above example, the video cameras do not have to be connected to a separate power source, but may obtain their power directly from the cable 30 .
[0047] If the length of the cable 30 is longer than some critical length (as determined by the actual technology of the cable 30 ), a cable extender 50 may be used to boost the cable 30 signals and allow the cable 30 length to be extended. A programming sequencer 54 may be included. Programming sequencer 54 may be a programmable computing device or a manual device. The preferred function of the programmed sequencer 54 is to provide the control signal generator 44 with the commands needed to control the transmitters 40 and receivers 46 . The cable status monitor 146 listens to the various signals on the cable 30 and allows them to be monitored to insure proper working of the system.
[0048] Normally, each video frame of the video source is sent at a time interval that is determined by a clocking source contained with each audio/video source 42 (i.e. a self synchronized clocking source that generates the horizontal and vertical synchronization signals. Thus, the start of a video frame from one source may not coincide in time with the start of the frame from another video source. In this case, when audio/video sources 42 are switched from one to another, the video picture on the audio/video user device 48 will require some time to resynchronize to the new video source 42 .
[0049] Audio/video user 48 may include a video monitor or station, video tape recorder, or any other suitable recording, viewing, monitoring, or storage apparatus.
[0050] FIG. 8 provides another illustration of the operation of the present invention. FIG. 8 shows two video sources and transmitters labeled VS 1 and VS 2 . A control signal generator 44 and programming sequencer 54 send control signals 87 over the cable to alternately allow video frames 320 from transmitter VS 1 and video frames 326 from transmitter VS 2 to be sent over the cable. The control signal generator 44 and programming sequencer 54 also send control signals 87 over the cable to alternately allow video frames 320 sent from transmitter VS 1 to be received by receiver VS 1 , and video frames 326 from transmitter VS 2 to be received by receiver VS 2 . This works as follows:
[0051] The video source 42 sends a set of video frames into a cable connect switch 82 . The cable connect switch 82 is controlled by signals 85 sent from the control receiver/decoder 302 , which, in turn, is controlled by cable control signals 87 . The receiver is controlled by a similar control receiver/decoder 304 to turn on and off the cable receiver switch 306 . The programming sequencer 54 sends a command to transmitter VS 1 and receiver VS 1 to turn on their cable connect switches 82 and 306 . This allows a single video frame 322 from the video stream 320 sent by the video source 42 over the cable to be received by receiver VS 1 so that the video frame 322 is sent to a video user 48 . The programming sequencer 54 then sends a command to transmitter VS 2 and receiver VS 2 to turn on their cable connect switches 82 and 306 after the end of the current video frame. This allows a single video frame 328 from the video stream 326 sent by the video source 42 over the cable to be received by receiver VS 2 so that the video frame 328 is sent to a video user. This has the effect of multiplexing alternating video frames 324 over the cable.
[0052] FIGS. 2A and 2B are illustrative schematic views showing power modules 34 that place electrical power on the cable 30 . Electrical power is supplied from either a battery 64 , AC utility power 70 , or from any of a wide variety of other sources. This power is then converted via battery converter/regulator 63 or AC power supply 68 to a voltage that is significantly higher then the voltage requirements of the audio/video sources 42 . It is then coupled to the cable 30 as cable power 62 using a power cable coupler 60 in such a manner that electrical current cannot flow back through either the AC power supply 68 or the battery converter/regulator 63 . This is so that multiple power modules 34 may be used on the cable 30 to insure adequate power for all the audio/video user devices 48 over the entire length of the cable 30 . The purpose of supplying power at a higher then needed voltage is to compensate for a drop in the voltage of the cable power 62 due to long length of the cable 30
[0053] FIG. 3 shows a preferred illustrative embodiment of the self-synchronized transmitter 40 . Cable power 62 is sent to a power converter 72 , which reduces the voltage so that it is compatible with the power requirements (A/V power 74 ) of the audio/video source 42 and the A/V transmitter 40 . Control signals 87 from the cable 30 are sent to the control receiver/decoder 88 . The transmitter 40 contains a unique address, which is decoded by the control receiver/decoder 88 along with other commands destined for this address. This control receiver/decoder 88 decodes commands from the cable, and controls both cable connect/disconnect signals 85 and amplifier control signals 83 . The connect/disconnect signals 85 control the cable connect switch 82 . The connect switch 82 connects the audio/video in from source 89 to the cable 30 when it is in the ON state, or disconnects itself from the cable 30 when it is in the OFF state. The control receiver/decoder 88 responds to cable control signals 87 to set the cable connect/disconnect signal 85 either to ON or OFF. In addition, other audio/video signal characteristics (such as signal gain, audio or video equalization characteristics, etc.) may be controlled by the amplifier control signal 83 . The amplifier control signal 83 controls the desired characteristics of the A/V amplifier and signal conditioner 84 . This is a variable gain amplifier with controllable equalization parameters. It may also have other characteristics for special functions. In other, simpler implementations, if the signal from the A/V source 89 is of sufficient strength, it is not necessary for the A/V amplifier and signal conditioner 84 to be present. Audio/video information comes in to the transmitter 40 through the A/V in from source 89 and is received by the A/V receiver 86 . This A/V receiver 86 simply provides correct termination of A/V in from source 89 signals. In addition, the Control Receiver/Decoder 88 has the capability of providing control signals 200 for devices that are contained within the AV Source 42 . The Control Receiver/Decoder 88 optionally has the capability of receiving device control signals from the Control signal generator 140 , converting these signals 200 to match the requirements of the AV Source 42 , and sending these to the AV Source 42 .
[0054] The signal flow through the transmitter 40 is as follows. The audio/video signals from the source come into the transmitter 40 via the A/V in from source 89 circuit and received by the A/V receiver 86 . These signals can flow, if desired, through the A/V amplifier and signal conditioner 84 to the cable connect switch 82 , where they then flow out over the cable 30 .
[0055] FIG. 4 shows the preferred embodiment of the self-synchronized receiver 46 . Each receiver 46 has a unique address. With reference to FIG. 4 , cable control signals 87 contain addresses and commands from the cable 30 and are decoded via the A/V control receiver/decoder 112 . The control receiver/decoder 112 responds to the commands addressed to this receiver and changes the state of the receiver connect/disconnect signals 114 . These signals turn the audio or video (or some other combination) ON or OFF from the A/V cable receiver 118 . In addition, the Control Receiver/Decoder 112 has the capability of providing control signals 201 for devices that are contained within the AV User 48 . The Control Receiver/Decoder 112 optionally has the capability of receiving device control signals from the Control signal generator 140 , converting these signals 201 to match the requirements of the AV User 48 , and sending these to the AV User 48 . In an alternate embodiment, it may be desirable not to utilize control signals to activate/deactivate receivers, such that the receivers continuously communicate with signals transmitted over the distribution cable.
[0056] In the preferred embodiment of the present invention, the signal flow is as follows: audio/video signals 81 from the cable 30 enter the A/V cable receiver 118 . The A/V cable receiver 118 continually monitors the audio/video signals 81 from the cable 30 in a fashion that does not interfere or cause loading of the cable 30 . The A/V cable receiver 118 is controlled by the connect/disconnect signals 114 discussed above. The output of the A/V cable receiver 118 is sent to the A/V output driver 120 , which conditions the audio/video output 122 for transmission to the A/V user.
[0057] FIG. 5 shows a preferred embodiment of the control signal generator of the present invention. Control signal generator sequencing signals 144 enter the Control signal generator Module 140 as shown. This Control signal generator Module 140 converts the sequencing signals 144 into the proper cable control signals 87 for the cable 30 . The Control signal generator Module 140 may change media type as well. If the control signals and audio/video portion of the cable 30 is composed of fiber optic cable, then the Control signal generator Module 140 would provide the proper conversion from electrical to optical. The Control signal generator Module 140 also provides buffering and timing, sending the cable control signals 87 over the cable 30 in the proper time sequence. In addition, the Control signal generator Module 140 has the capability of receiving device control information 202 from an external source, converting to the proper cable control signals 87 , and sending it to the proper Transmitter 40 or Receiver 46 .
[0058] FIG. 6 shows the cable status monitor 146 . This monitor samples the cable control signals 87 , the cable power 62 , and the cable A/V signals 81 . It compares these signals against a reference standard, and if these signals are not within tolerance, alarms are generated to indicate malfunction conditions.
[0059] FIG. 7 shows a preferred embodiment of the cable extender 50 of the present invention. The cable extender 50 contains a set of reversing switches 148 , 154 and 160 . Because the repeaters 150 and 152 perform their function in only one direction, provision must be made to reverse the “direction” of the repeaters 150 and 152 . The cable A/V signals 81 are brought into an A/V cable repeater reversing Switch 148 and A/V cable repeater 150 . The A/V cable repeater 150 amplifies and regenerates the audio/video signals on the cable 30 . The purpose of the reversing switches are to provide this “reversal” so the repeaters 150 and 152 ) may be set to the proper “direction” to properly repeat or regenerate the signal. An example of this is if the audio/video source is connected to the left side of FIG. 7 , the “direction” of the A/V cable repeater 150 is correct. If the audio/video source is connected to the right side of FIG. 7 , the “direction” of the A/V repeater 150 must be reversed.
[0060] A/V cable repeater reversing switch 148 and A/V repeater 150 are for the cable A/V signals 81 . Reversing switch 154 and control signal cable repeater 152 are for the control signals 87 . For cable power 62 , a cable power cutoff switch 160 is used to break the continuity of the cable power 62 so that additional cable power may be introduced onto the cable in order to bring the cable power back into tolerance. The repeater power selector switch 162 simply lets additional cable power flow either to the left or right of the cutoff switch to account for the location of the power module 34 . The reversing switches may configure themselves properly by automatically sensing the signal direction on the cable.
[0061] In the preferred embodiment, the cable 30 is comprised of individual twisted pair copper conductors for the cable A/V signals 81 , and cable control signals 87 . Straight copper conductors are preferably utilized for cable power 62 . However, it will be appreciated by those skilled in the art that the cable A/V signals 81 , and control signals 87 may be of different technology, including coaxial cable (either individual or multiplexed), or optical fiber (either individual or multiplexed). The control signal 87 protocols and levels may be either proprietary (such as the Dallas/Maxim Semiconductor Microlan technology), or a standard protocol, including IEEE LAN protocols. The cable power 62 may be direct current, alternating current, or some other combination.
[0062] Since many modifications, variations, and changes in detail can be made to the described preferred embodiments of the invention, it is intended that all matters in the foregoing description and shown in the accompanying drawings be interpreted as illustrative and not in a limiting sense.
[0063] Thus, the scope of the invention should be determined by the appended claims and their legal equivalents. | An audio/video distribution system that is cost-effective, highly flexible, and capable of being used over an extended area and without the need for a centralized switching and distribution mechanism. The audio/video distribution system includes a distribution cable, at least one audio/video transmitter, at least one receiver, and a control director. The transmitter is configured to receive signals from at least one audio/video source while the receiver is connected to the distribution cable and configured to receive signals from the distribution cable. The control director is connected to the distribution cable and configured to control the transmitter and receiver. | 7 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates, in general, to a reinforcing geotextile mat and an embankment method using the same, and more particularly, to a reinforcing geotextile mat which is manufactured by assembling support members in a geotextile mat to serve as a retaining wall and an embankment method which uses the reinforcing geotextile mat to reduce the construction cost and shorten the construction period.
[0003] 2. Description of the Prior Art
[0004] Due to environmental or economic issues, it is frequently required to form a steeply inclined natural or artificial slope. In such a situation, in order to secure structural and dynamic stability of the slope, multiple layers of geotextile are used while constructing the slope.
[0005] In addition to the case of forming a steeply inclined slope, geotextile is used in the case of restoring a broken slope with the aim of reinforcing the ground.
[0006] In addition, geotextile is used to reinforce areas upstream and downstream from a dam and increase the height of the dam, construct a temporary flood control structure, reinforce an abutment of a bridge and decrease the span of the bridge, construct a temporary bypass road, and construct a levee using water-containing fine particles.
[0007] An example of a conventional construction method using the geotextile is disclosed in Korean Patent No. 10-419883 entitled “Slope plantation earth reinforcement method”, which will be described with reference to FIGS. 8 a through 8 i.
[0008] The conventional slope plantation earth reinforcement method is implemented as described below.
[0009] As shown in FIG. 8A , after the in-situ ground is hardened, a plurality of steel bars 10 are laid out on the in-situ ground.
[0010] Next, as shown in FIG. 8B , support tubes 36 of a form board 30 are inserted around ends of the steel bars 10 to fix the form board 30 at a predetermined position.
[0011] Then, as shown in FIG. 8C , a vegetation mat 40 and a lapping textile 42 are installed on the in-situ ground and the form board 30 , and then a first embankment layer 52 having a predetermined height is formed and hardened on the in-situ ground.
[0012] Thereafter, as shown in FIG. 8D , a step-shaped embankment wall 54 is formed on the first embankment layer 52 .
[0013] Successively, as shown in FIG. 8E , the first embankment layer 52 and the embankment wall 54 are lapped using a lapping textile 42 .
[0014] Next, as shown in FIG. 8F , a second embankment layer 56 is formed on the first embankment layer 52 to have the same height as a support section 32 .
[0015] Then, as shown in FIG. 8G , by moving the form board 30 forward by a predetermined distance and fixing the form board 30 to steel bars 10 ,
[0016] Then, as shown in FIG. 8H , a predetermined space 57 is defined in front of the embankment layers 52 and 56 , and a vegetation soil layer 58 is formed in the space 57 .
[0017] Finally, as shown in FIG. 8I , the upper part of the vegetation soil layer 58 is covered by a vegetation mat 40 , and ends of the vegetation mat 40 are appropriately fixed.
[0018] However, the conventional earth reinforcement method has a drawback in that, since the form board must be repeatedly installed and uninstalled in order to form the embankment layers, the construction cost increases and the construction period is lengthened.
[0019] Further, because an embankment layer may only be formed after a previous embankment layer is completely hardened, the construction period is further lengthened.
[0020] Meanwhile, U.S. Pat. No. 5,161,917 discloses a method of and an element for the production of structures for containing areas of ground. In this publication, an element for use in producing stabilized soil structures comprises a sheet of double-twisted galvanized and plastic-coated metal mesh which has on one end a box portion made from panel of the sheet panels and folded up from the end of the sheet and an additional transverse panel fixed to the sheet. In use, a plurality of elements are superposed with the box portions providing the anterior wall of the structure and the remainder of each sheet extending back into the structure to stabilize the structure. Each element is filled and covered with fill material before a succeeding element is positioned on it. The fold lines of panels are defined by strips introduced into the mesh of sheet during manufacture.
[0021] This conventional technique suffers from defects in that, since the box portions must be folded and installed in situ, workability is degraded, and since specific holding means is not provided, it is difficult to handle the element.
[0022] Also, U.S. Pat. No. 6,357,970 discloses an improved method and apparatus for constructing a soil reinforced earthen retaining wall. In this publication, successive soil reinforcing mats embedded within an earthen formation have bent-up face elements which are slidably engaged to enable the earthen formation to settle without bulging the face elements. Backing mats are disposed behind the face elements for movement relative thereto in generally vertical planes. The backing mats serve to support the successive soil reinforcing mats and permit the mats to more toward one another to accommodate settling of the formation without bulging of the face elements.
[0023] However, this technique still encounters the same problems as described above in connection with the conventional arts.
SUMMARY OF THE INVENTION
[0024] Accordingly, the present invention has been made keeping in mind the above problems occurring in the prior art, and an object of the present invention is to provide a reinforcing geotextile mat which has support members capable of supporting an embankment layer.
[0025] Another object of the present invention is to provide an embankment method which uses a reinforcing geotextile mat to reduce a construction cost and shorten a construction period.
[0026] In order to achieve the first object, according to one aspect of the present invention, there is provided a reinforcing geotextile mat comprising support means arranged at both ends of the reinforcing geotextile mat, to support a predetermined amount of embankment soil, with a portion of each support means embedded in backfilled soil.
[0027] According to another aspect of the present invention, there is provided a reinforcing geotextile mat comprising support means arranged at one end of the reinforcing geotextile mat, to support a predetermined amount of embankment soil, with a portion of the support means embedded in backfilled soil; and an accommodating section arranged at the other end of the reinforcing geotextile mat, to accommodate an element to be fixedly held, with the entire accommodating section embedded in the embankment soil.
[0028] According to another aspect of the present invention, the support means comprises a horizontal support section for supporting the backfilled soil in a vertical direction; a vertical support section for supporting the backfilled soil in a horizontal direction; and an inclined support section defined with openings through which the backfilling soil passes and inclinedly embedded in the backfilled soil.
[0029] According to another aspect of the present invention, when assuming that lengths of the horizontal support section, the vertical support section and the inclined support section are respectively L H1 , L V1 and L C1 , L H1 =3.5˜4.5*L V1 and L C1 =3.9˜5.0*L V1 .
[0030] According to another aspect of the present invention, the horizontal support section, the vertical support section and the inclined support section have a horizontal receiving portion, a vertical receiving portion and an inclined receiving portion, respectively, into which external support members for increasing supporting force are inserted.
[0031] According to another aspect of the present invention, when assuming that lengths of the horizontal receiving portion, the vertical receiving portion and the inclined receiving portion are respectively L H2 , L V2 and L C2 , L H2 =0.6˜1.0*L V2 and L C2 =0.2˜0.5*L V2 .
[0032] In order to achieve the second object, according to another aspect of the present invention, there is provided an embankment method using a reinforcing geotextile mat, comprising (a) step for positioning the reinforcing geotextile mat on the ground or hardened embankment soil in a deployed state; (b) step for inserting external support members in a horizontal receiving portion, a vertical receiving portion and an inclined receiving portion of the reinforcing geotextile mat; and (c) step for backfilling a horizontal support section, a vertical support section and an inclined support section of the reinforcing geotextile mat with soil, and then placing and hardening embankment soil on the reinforcing geotextile mat so that the embankment soil has a predetermined height, wherein steps (a), (b) and (c) are implemented one or more times.
[0033] According to still another aspect of the present invention, step (b) comprises the step of inserting the external support members through the receiving portions of a plurality of reinforcing geotextile mats to laterally couple the plurality of reinforcing geotextile mats to one another.
[0034] According to yet still another aspect of the present invention, step (c) comprises the step of installing a drainpipe defined with a plurality of through-holes, adjacent to the support sections of the reinforcing geotextile mat.
BRIEF DESCRIPTION OF THE DRAWINGS
[0035] The above and other objects, features and other advantages of the present invention will be more clearly understood from the following detailed description when taken in conjunction with the accompanying drawings, in which:
[0036] FIG. 1 is a schematic perspective view illustrating a reinforcing geotextile mat in accordance with a first preferred embodiment of the present invention;
[0037] FIGS. 2A through 2C are schematic views illustrating a procedure for manufacturing the reinforcing geotextile mat shown in FIG. 1 ;
[0038] FIG. 3 is a schematic perspective view illustrating a reinforcing geotextile mat in accordance with a second preferred embodiment of the present invention;
[0039] FIGS. 4A through 4C are schematic views illustrating a procedure for manufacturing the reinforcing geotextile mat shown in FIG. 3 ;
[0040] FIGS. 5A through 5E are schematic views illustrating an embankment method in accordance with a third preferred embodiment of the present invention, which uses the reinforcing geotextile mat shown in FIG. 1 ;
[0041] FIGS. 6A through 6E are schematic views illustrating an embankment method in accordance with a fourth preferred embodiment of the present invention, which uses the reinforcing geotextile mat shown in FIG. 3 ;
[0042] FIG. 7 is a schematic view illustrating a state in which a plurality of reinforcing geotextile mats shown in FIGS. 1 and 3 are coupled to one another; and
[0043] FIGS. 8A through 8I are schematic views illustrating a conventional earth reinforcement method.
DETAILED DESCRIPTION OF THE INVENTION
[0044] Reference will now be made in greater detail to preferred embodiments of the invention, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numerals will be used throughout the drawings and the description to refer to the same or like parts.
[0045] First, reinforcing geotextile mats in accordance with preferred embodiments of the present invention will be described with reference to FIGS. 1 through 4 C.
First Embodiment
[0046] A reinforcing geotextile mat in accordance with a first preferred embodiment of the present invention will be described with reference to FIGS. 1 through 2 C.
[0047] As shown in FIG. 1 , a reinforced geotextile mat 100 has at both ends thereof support means each of which serves as a retaining wall for supporting embankment soil.
[0048] The support means is composed of an inclined support section 110 , a vertical support section 120 and a horizontal support section 130 .
[0049] The inclined support section 110 is a section to be embedded and fixedly maintained in the embankment soil. The inclined support section 110 is formed with a first opening 101 , a second opening 102 and a third opening 103 .
[0050] While, in this embodiment of the present invention, the openings 101 , 102 and 103 are defined to have a rectangular shape, the shape and number of the openings are not specifically limited so long as backfilling soil can easily pass through the openings.
[0051] The inclined support section 110 has a first stitched portion 111 , a second stitched portion 112 and a third stitched portion 113 which are formed by turning over or superposing and stitching one or more cut portions of the reinforcing geotextile mat 100 .
[0052] In this way, by turning over or superposing one or more cut portions at one side or both sides of each of the openings 101 , 102 and 103 and then forming the stitched portions 111 , 112 and 113 , the tensile strength of the inclined support section 110 is increased.
[0053] The vertical support section 120 is a section to support backfilled soil in a horizontal direction, and has a first superposed portion 121 which is partially connected to the inclined support section 110 .
[0054] A vertical receiving portion 132 into which a first external support member (not shown) is inserted is formed between the vertical support section 120 and the first superposed portion 121 , and an inclined receiving portion 131 into which the first external support member (not shown) is inserted is formed between the inclined support section 110 and the first superposed portion 121 .
[0055] While, in this embodiment, the inclined receiving portion 131 and the vertical receiving portion 132 are formed to communicate with each other, it is to be readily understood that they may be formed to be partitioned from each other.
[0056] The horizontal support section 130 is a section to support the backfilled soil in a vertical direction, and is connected at one end thereof to the vertical support section 120 and at the other end thereof to a base 150 of the reinforcing geotextile mat 100 .
[0057] The horizontal support section 130 has a second superposed portion 122 .
[0058] A horizontal receiving portion 133 into which a second external support member (not shown) is inserted is formed between the horizontal support section 130 and the second superposed portion 122 .
[0059] When assuming that lengths of the inclined support section 110 , the vertical support section 120 and the horizontal support section 130 are respectively L H1 , L V1 and L C1 , lengths of the inclined receiving portion 131 , the vertical receiving portion 132 and the horizontal receiving portion 133 are respectively L H2 , L V2 and L C2 , and L V1 ≅L V2 =L, it is preferred from structural and dynamic points of view that the lengths satisfy the following equations 1.
L C1 =3.9˜5.0 *L
L H1 =3.5˜4.5 *L
L C2 =0.2˜0.5 *L
L H2 =0.6˜1.0 *L [Equations 1]
[0060] The above-described reinforcing geotextile mat 100 is manufactured as shown in FIGS. 2A through 2C .
[0061] First, as shown in FIG. 2A , on each end of the reinforcing geotextile mat 100 , the first opening 101 , the second opening 102 and the third opening 103 are defined by cutting portions of the reinforcing geotextile mat 100 to have a predetermined interval and a predetermined length.
[0062] Next, as shown in FIG. 2B , in order to form the openings 101 , 102 and 103 , one or more cut portions are turned over or superposed and then stitched to the reinforcing geotextile mat 100 to form the first stitched portion 111 , the second stitched portion 112 and the third stitched portion 113 .
[0063] Further, a piece of preselected material, preferably, a piece of geotextile, is superposed on the reinforcing geotextile mat 100 adjacent to the openings 101 , 102 and 103 and then stitched to the reinforcing geotextile mat 100 to form the first superposed portion 121 , the second superposed portion 122 , a fourth stitched portion 114 , a fifth stitched portion 115 and a sixth stitched portion 116 .
[0064] At this time, it is preferred that the length of the first superposed portion 121 be set to be slightly greater than the sum of the lengths of the inclined receiving portion 131 and the vertical receiving portion 132 , and the length of the second superposed portion 122 be set to be slightly greater than the length of the horizontal receiving portion 133 .
[0065] Finally, as shown in FIG. 2C , a portion of the reinforcing geotextile mat 100 , which is to be formed as the inclined support section 110 having the openings 101 , 102 and 103 , is folded in the direction indicated by the arrow, and the distal end of the folded portion is stitched to the reinforcing geotextile mat 100 to form a seventh stitched portion 117 .
Second Embodiment
[0066] A reinforcing geotextile mat in accordance with a second preferred embodiment of the present invention will be described with reference to FIGS. 3 through 4 C.
[0067] As shown in FIG. 3 , a reinforcing geotextile mat 200 has support means which is arranged at one end of the reinforcing geotextile mat 200 and serves as a retaining wall for supporting embankment soil, and an accommodating section 260 which is arranged at the other end of the reinforcing geotextile mat 200 and is embedded in the embankment soil to accommodate an element to be fixed and thereby fixedly hold the reinforcing geotextile mat 200 with respect to the embankment soil.
[0068] Since the support means is constructed in the same manner as in the first embodiment, detailed description thereof will be omitted herein.
[0069] The accommodating section 260 is defined by forming an eighth stitched portion 118 through folding the other end of the reinforcing geotextile mat 200 and stitching the folded end to the reinforcing geotextile mat 200 .
[0070] While it is preferred that the accommodating section 260 be embedded in the embankment soil in a state in which a drainpipe 290 having a predetermined length is accommodated in the accommodating section 260 , the accommodating section 260 can be embedded in the embankment soil without using the drainpipe 290 .
[0071] The drainpipe 290 not only serves to fixedly hold the reinforcing geotextile mat 200 in the embankment soil, but also is formed with a plurality of through-holes 291 to drain water contained in the embankment soil to the outside.
[0072] The above-described reinforcing geotextile mat 200 is manufactured as shown in FIGS. 4A through 4C .
[0073] First, as shown in FIG. 4A , on one end of the reinforcing geotextile mat 200 , a first opening 201 , a second opening 202 and a third opening 203 are defined by cutting portions of the reinforcing geotextile mat 200 to have a predetermined interval and a predetermined length, and from the other end of the reinforcing geotextile mat 200 , a folding portion 200 a having a predetermined length is established.
[0074] Next, as shown in FIG. 4B , in order to form the openings 201 , 202 and 203 , one or more cut portions are turned over or superposed and then stitched to the reinforcing geotextile mat 200 to form a first stitched portion 211 , a second stitched portion 212 and a third stitched portion 213 .
[0075] Further, a piece of preselected material, preferably, a piece of geotextile, is superposed on the reinforcing geotextile mat 200 adjacent to the openings 201 , 202 and 203 and then stitched to the reinforcing geotextile mat 200 to form a first superposed portion 221 , a second superposed portion 222 , a fourth stitched portion 214 , a fifth stitched portion 215 and a sixth stitched portion 216 . And, the folding portion 200 a is folded and stitched to the reinforcing geotextile mat 200 to form an eighth stitched portion 218 .
[0076] At this time, it is preferred that the length of the first superposed portion 221 be set to be slightly greater than the sum of the lengths of an inclined receiving portion 231 and a vertical receiving portion 232 , and the length of the second superposed portion 222 be set to be slightly greater than the length of a horizontal receiving portion 233 .
[0077] Finally, as shown in FIG. 4C , a portion of the reinforcing geotextile mat 200 , which is to be formed as an inclined support section 210 having the openings 201 , 202 and 203 , is folded in the direction indicated by the arrow, and the distal end of the folded portion is stitched to the reinforcing geotextile mat 200 to form a seventh stitched portion 217 .
[0078] Next, embankment methods in accordance with preferred embodiments of the present invention will be described with reference to FIGS. 5A through 6E .
Third Embodiment
[0079] An embankment method in accordance with a third preferred embodiment of the present invention which uses the reinforcing geotextile mat shown in FIG. 1 will be described with reference to FIGS. 5A through 5E .
[0080] First, as shown in FIG. 5A , the reinforcing geotextile mat 100 is positioned on the ground in a deployed state.
[0081] Next, as shown in FIG. 5B , by inserting the first external support member 141 into the inclined receiving portion 131 and the vertical receiving portion 132 and inserting the second external support member 142 into the horizontal receiving portion 133 , the retaining wall for supporting the backfilled soil is formed. At this time, the embankment soil 10 is placed on the reinforcing geotextile mat 100 . In the case that a drainage system is required, depending upon the circumstances at an embankment installation spot, a drainpipe 143 may be installed at a predetermined location.
[0082] Then, as shown in FIG. 5C , after implementing backfilling work by evenly distributing the embankment soil 10 , the embankment soil 10 is hardened to have a predetermined height.
[0083] Thereupon, as shown in FIG. 5D , after a new reinforcing geotextile mat 100 is deployed on the embankment soil hardened in this way, the above-described procedure is repeated. In this regard, it is preferred that the size of the new mat installed on the hardened embankment soil be less than that of the previously installed mat.
[0084] Finally, as shown in FIG. 5E , green soil 20 is provided to each stepped portion which is formed between two layers of embankment soil.
Fourth Embodiment
[0085] An embankment method in accordance with a fourth preferred embodiment of the present invention which uses the reinforcing geotextile mat shown in FIG. 3 will be described with reference to FIGS. 6A through 6E .
[0086] First, as shown in FIG. 6A , the reinforcing geotextile mat 200 is positioned in a deployed state on the ground being adjacent to a slope 30 .
[0087] Next, as shown in FIG. 6B , by inserting a first external support member 241 into the inclined receiving portion 231 and the vertical receiving portion 232 and inserting a second external support member 242 into the horizontal receiving portion 233 , the retaining wall for supporting the backfilled soil is formed. At this time, the embankment soil 10 is placed on the reinforcing geotextile mat 200 . In the case that a drainage system is required, depending upon the circumstances at an embankment installation spot, a drainpipe 243 may be installed at a predetermined location.
[0088] Then, as shown in FIG. 6C , after implementing backfilling work by evenly distributing the embankment soil 10 , the embankment soil 10 is hardened to have a predetermined height.
[0089] Thereupon, as shown in FIG. 6D , after a new reinforcing geotextile mat 200 is deployed on the embankment soil hardened in this way, the above-described procedure is repeated. In this regard, it is preferred that the size of the new mat installed on the hardened embankment soil be less than that of the previously installed mat.
[0090] Finally, as shown in FIG. 6E , green soil 40 is provided to each stepped portion formed between two layers of embankment soil.
[0091] A plurality of the reinforcing geotextile mats 100 and 200 according to the above-described embodiments can be used in a state in which they are coupled to each other as shown in FIG. 7 .
[0092] As shown in the drawing, by placing the reinforcing geotextile mats 100 and 200 parallel to each other and inserting the first external support members 141 and 241 and the second external support members 142 and 242 through the inclined receiving portions 131 and 231 , the vertical receiving portions 132 and 232 and the horizontal receiving portions 133 and 233 of the respective reinforcing geotextile mats 100 and 200 , the plurality of mats 100 and 200 are coupled with one another.
[0093] At this time, it is to be noted that the first external support members 141 and 241 may be used in a bent state or may comprise two separate members.
[0094] As apparent from the above description, the reinforcing geotextile mat according to the present invention provides advantages in that, since the reinforcing geotextile mat itself has support members capable of supporting backfilled soil, auxiliary support structures such as a retaining wall and so forth are not needed when implementing the embankment.
[0095] Also, due to the fact that an inclined support section of the reinforcing geotextile mat is defined with a plurality of openings, it is possible to backfill soil through the openings.
[0096] Further, because the reinforcing geotextile mat has a plurality of superposed portions and stitched portions, the reinforcing geotextile mat has increased tensile strength.
[0097] Moreover, due to the fact that the reinforcing geotextile mat can be manufactured in large quantities for various sizes in a factory and then can be used through simple assembly work at embankment implementation spots, a construction cost can be significantly reduced.
[0098] Furthermore, as a plurality of reinforcing geotextile mats can be used in a state in which they are connected to one another, the reinforcing geotextile mat can be freely used irrespective of the scale of an embankment implementation spot.
[0099] In addition, the embankment method according to the present invention which uses the above-described reinforcing geotextile mat provides advantages in that, since it is possible to stack another reinforcing geotextile mat on an embankment layer in a state in which backfilled soil of the embankment layer has not completely hardened, a construction period can be remarkably shortened.
[0100] Although preferred embodiments of the present invention have been described for illustrative purposes, those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims. | A reinforcing geotextile mat and an embankment method using the same. The mat comprises support means for supporting backfilled soil at one end or both ends of the mat. The support means comprises a horizontal support section for supporting the backfilled soil in a vertical direction; a vertical support section for supporting the backfilled soil in a horizontal direction; and an inclined support section defined with openings through which the backfilling soil passes and inclinedly embedded in the backfilled soil. The method comprises the steps of positioning a reinforcing geotextile mat on the ground or hardened embankment soil; inserting external support members in horizontal, vertical and inclined receiving portions of the mat; and backfilling horizontal, vertical and inclined support sections of the mat with soil, and then placing and hardening embankment soil on the mat. These steps are implemented one or more times. | 4 |
BACKGROUND
The present invention relates to a wheel for at least partially muscle-powered vehicles and in particular for bicycles.
Many different types of bicycle wheels have become known in the prior art. Hollow rims tend to be used with the spoke nipples disposed in the region of the hollow space between the rim base and the rim well. For reinforcing the rim base, rim eyelets may be employed which, as shown e.g. in FIG. 6 of EP 0 715 001 B1, connect the rim well and the rim base in the radial direction. The rim eyelets reinforce among other things the rim base.
US 2003/0090141 A1 discloses a wheel for bicycles where a cylindrical spacer sleeve is inserted between the rim base and the spoke nipple in the region of the rim hollow so as to ease the spoke at the transition between its threaded portion for screw-fastening to the spoke nipple and the non-threaded spoke portion. The bearing surface of the spoke nipple at the cylindrical spacer sleeve may be spherical so as to allow angular orientation of the spoke. To ensure the function the US 2003/0090141 A1 requires the cylindrical spacer sleeve to be of such a height as to result in a spoke bend in the region of the wheel radius. A height of 5 mm has been found to be advantageous for the cylindrical spacer sleeve. This wheel shows the drawback that the region of the rim hollow must be designed very high in the radial direction to accommodate the cylindrical spacer sleeve and the spoke nipple.
For reducing the total weight of a wheel having a metal rim, EP 0 715 001 B1 shows in FIG. 8 a rim which had been subjected to chemical post-processing for reducing rim material in such a way as to retain reinforced areas at the spoke holes only.
U.S. Pat. No. 6,402,256 B1 describes as an alternative, mechanical post-processing of the rim wall thickness such that in the spoke hole areas the rim wall thickness is greater than in other areas. This also allows a reduced weight of the rim.
While a rim according to U.S. Pat. No. 6,402,256 B1 and also the rim according to EP 0 715 001 B1 can be manufactured lightweight and functional, manufacturing involves complicated steps, thus making the rims expensive.
SUMMARY
It is therefore the object of the present invention to provide a wheel in particular for a bicycle that allows a reduced weight and high stability with reduced manufacturing work. This wheel comprises a rim, a hub and a plurality of spoke systems connecting the rim with the hub. Each of the spoke systems comprises a spoke and a spoke nipple. At least one spoke system comprises a reinforcing unit with a through hole. The wheel may be configured as a rear wheel or else as a front wheel.
A wheel according to the invention for at least partially muscle-powered vehicles and in particular two-wheeled vehicles comprises a hub and a rim having a plurality of spoke holes and a plurality of spoke systems for connecting the hub with the rim. A spoke system comprises at least a spoke and a spoke nipple. At least one reinforcing unit is provided with a through hole and is provided or disposed between the rim and the spoke nipple. The reinforcing unit is a disk-type and is configured curved about at least one longitudinal axis. The reinforcing unit comprises a convex inner rim contact surface for bearing against a matched, concave orientation area of the rim. The reinforcing unit comprises a concave outside surface. The outside surface is provided with a nipple accommodation at a depression having a concave nipple contact surface with a narrower curvature. The nipple accommodation with the narrower, concave nipple contact surface serves to accommodate a matching, convex supporting area for the spoke nipple.
The wheel according to the invention has many advantages since it allows the cost effective manufacture of a wheel showing high stability and a low total weight. A low total weight can be obtained due to the reinforcing unit that is only configured as a disk-type since because of its disk structure it shows a small volume and thus a low weight. The disk structure does not require any shoulders or appendices for positioning or fixing the reinforcing unit.
The curved configuration of the reinforcing unit around at least one longitudinal axis and its convex, i.e. outwardly curved rim contact surface, provides preferred matching to the concave area, i.e. the inwardly curved area of the rim. A desired force transition from the spoke nipple through the reinforcing unit to the rim base is enabled. Preferably the reinforcing unit is not required to deform first. The structure of the reinforcing unit is preferably directly matched to the structure of the rim. Thus the reinforcing unit fits substantially snugly to the rim when it is inserted into the rim.
Another advantage is that the reinforcing unit can orient itself to the rim since the contours are matched. The contour is in particular approximated to circle segments such that contact over the surface will be retained even if the reinforcing unit is slightly displaced.
It is furthermore advantageous that no separate orientation contour or holder of the reinforcing unit to the rim well is required. The reinforcing unit does not require a specific orienting aid but it is preferably self-orienting during assembly.
A considerable advantage is achieved by the concave outside surface with the nipple accommodation provided thereat having a concave nipple contact surface with a narrower curvature. The spoke nipple accommodated at the nipple accommodation can orient itself relative to the reinforcing unit. The convex supporting area of the spoke nipple can orient itself relative to the concave nipple contact surface. Moreover, the supporting surface of the nipple on the reinforcing unit is preferably enlarged so as to considerably reduce the surface pressure.
Thus, two separate orienting options independent from one another are provided. The reinforcing unit can orient itself relative to the rim, and the spoke nipple can orient itself relative to the reinforcing unit. On the whole a preferred orientation with desired force transmission is enabled so as to achieve lightweight, firm wheels.
Preferably the reinforcing unit has a thickness that is less than the maximum diameter of the spoke and in particular less than the maximum diameter of the spoke shaft. Thus the reinforcing unit occupies just a small volume so as to generate a low weight even if steel is used as the material for the reinforcing unit such that on the whole a particularly lightweight wheel can be manufactured.
The disk-type structure of the reinforcing unit and the contact surface matched to the rim allow a desired transition of forces so that the wall thickness of the rim can be complementarily dimensioned.
The rims used are preferably of metal and are manufactured from an extruded profile. The rim blank used is then a piece of the extruded profile that basically shows consistent wall thicknesses over its length in every place of the cross section. This means that each cross section is identical, apart from the spoke holes.
This means that a slight reduction of the rim wall thickness in the area of the rim base already considerably reduces the weight of the entire rim, since said wall thickness is reduced accordingly over the entire circumference. Moreover, the wheel mass distanced from the axle is reduced. This reduces the moment of inertia of the wheel which improves the wheel dynamics.
Now, due to the reinforcing units the wall thickness is increased precisely in those positions which require a higher strength. At the same time the reinforcing units are preferably made of a high-strength material such as steel, while the rim blank or body per se preferably consists of a light metal or a light metal alloy. This results in a lightweight and stable wheel that is easy to manufacture.
The wall thickness of the rim, in particular in the region of the rim base, can be reduced compared to conventional wall thicknesses. The wall thickness may be reduced by 10% and even 20% or more.
The wheel according to the invention includes simple components which can be manufactured at low cost while also offering considerable saving of weight. No complicated molds or chip-producing or chemical finishing work to the rim, the spoke nipples or the reinforcing unit are required.
Although the requirement of saving weight has existed for quite some time, the solutions disclosed thus far have been considerably more complicated and moreover show a higher weight.
Preferably the thickness of the reinforcing unit varies less than 25% over the entire reinforcing unit, other than a tapered down, central nipple accommodation.
The depression comprising the nipple accommodation may be milled out. The depression may be configured by squashing. The depression may be embossed or forged.
In preferred configurations, the spoke nipples protrude radially inwardly through the spoke holes in the rim.
In advantageous specific embodiments, the quantity of spoke nipples differs from the quantity of reinforcing units. This means that the reinforcing units are disposed at a fraction of the spoke nipples only. The quantity of spoke nipples may in particular be larger than the quantity of reinforcing units. It is possible for reinforcing units to be provided at a few individual spokes only. For example spokes subjected to lower loads may be provided without reinforcing units.
It is possible to provide no reinforcing units or thinner or lighter reinforcing units for specific and e.g. radially oriented spokes. Spokes subjected to higher loads which may e.g. be oriented tangentially may be provided with stronger or larger reinforcing units. Then, the rim is reinforced locally in dependence on the loads occurring.
Preferably at least one spoke hole is provided without a reinforcing unit. Preferably at least one spoke hole is provided with the spoke nipple resting on the edge of the spoke hole.
In all the configurations, it is possible for different and in particular at least two different reinforcing units to be provided which differ in at least one dimension and/or in the material. It is possible for at least two reinforcing units to differ in their size, length, width, and/or thickness.
Preferably the rim substantially consists of an extruded profile in particular of at least one light metal. Preferably the concave nipple contact surface having a narrower curve extends at least in one direction transverse to the longitudinal axis. In the mounted state the longitudinal axis is in particular oriented along the rim circumference so that the narrower curve of the concave nipple contact surface extends in parallel or at least approximately in parallel to an axis of symmetry of the rim and/or of the wheel. This allows an angular orientation of a spoke relative to a righthand or lefthand end and thus e.g. relative to both the hub flanges of a corresponding hub. Then the spoke does not require bending but it can extend in a straight line between the rim and the hub so as to increase durability and stressability.
A thickness of at least one reinforcing unit is in particular less than one fourth of the width and in particular less than one fourth of the length of the reinforcing unit. The reinforcing unit is particularly preferably configured oval or round and is between approximately 7 mm and 14 mm in length and/or width. In preferred configurations, a maximum dimension of the reinforcing unit is less than twice the maximum diameter of the spoke nipple.
In preferred configurations, at least one reinforcing unit has a maximum thickness of less than 2.0 mm and preferably less than 1.5 mm and in particular less than 1.0 mm. This allows a particularly thin and thus lightweight reinforcing unit which thus contributes to a considerable weight reduction of the entire wheel. A major factor is the disk-type structure having a low thickness. A thin and flat reinforcing unit improves mountability since in the case of a hollow rim it can be inserted more readily into the hollow through the hole in the rim well.
In the case that different reinforcing units are provided, they may differ e.g. in their thickness and or in their length and width. For example, the reinforcing units provided may be thicker by 25% or 50% in positions subjected to higher loads. It is also possible for the supporting surfaces of the reinforcing units to differ by 25% or 50%. Combined variations of the supporting surface and the thickness are likewise possible.
At least one reinforcing unit consists and in particular all the reinforcing units consist preferably of metal and in particular of steel. The rim preferably consists at least partially of metal and/or at least one fibrous composite material.
A minimum thickness of the reinforcing unit at the nipple accommodation is preferably between one third and two thirds of a maximum thickness of the reinforcing unit. A minimum thickness of the reinforcing unit is preferably at least 0.2 mm. Too thin wall thicknesses can compromise the reproducibility of the functions. However, the minimum wall thickness also depends on the material used and it may be less in the case of particularly stable materials.
Preferably the concave nipple contact surface of the central nipple accommodation has a radius of curvature that is less than half the radius of curvature of the concave outside surface of the reinforcing unit. Thus, at the reinforcing unit that is curved on the whole, a nipple accommodation is defined that is provided as a recess within the material of the disk-type reinforcing unit. This means that the curvature of the nipple contact surface is configured greater than the curvature of the concave outside surface on the whole. The nipple accommodation may, for example, be configured as a spherical seat whose radius is larger than the radius of the through hole.
Preferably the center of the nipple accommodation is disposed at such a distance from the reinforcing unit that a circumferential segment in the region of the nipple accommodation lies substantially entirely within the disk structure of the reinforcing unit.
In all the configurations, it is preferred for a radius of curvature of the concave nipple contact surface of the reinforcing unit to be between 2 mm and 4 mm. Preferably, a radius of curvature of the convex, inner rim contact surface of the reinforcing unit and/or a radius of curvature of the concave outside surface of the reinforcing unit is between 4 mm and 20 mm.
The rim is preferably configured as a hollow rim, being between 15 and 40 mm in width and in particular between 16 and 38 mm and preferably between 17 mm and 36 mm.
A height of the hollow rim is in particular at least 18 mm and preferably at least 20 mm. The height may be up to 100 mm. It is preferred though for the height to be in the range between approximately 20 and 40 mm.
The spoke nipple preferably has a spherical head and at least one tool engagement point, e.g. a Torx or an internal hexagon, an external hexagon, and/or a square. The tool engagement point in particular projects at least partially inwardly through the spoke hole.
BRIEF DESCRIPTION OF THE DRAWINGS
Further advantages and features of the present invention can be taken from the description of the exemplary embodiment which will be discussed below with reference to the enclosed figures.
The figures show in:
FIG. 1 a simplistic view of a bicycle equipped with wheels according to the invention;
FIG. 2 a simplistic view of another bicycle equipped with wheels according to the invention;
FIG. 3 a cross-section of a wheel according to the invention;
FIG. 4 a perspective illustration of the reinforcing unit of the wheel according to FIG. 3 ;
FIG. 5 a top view of the reinforcing unit according to FIG. 3 ;
FIG. 6 a cross-section of the reinforcing unit according to FIG. 5 ;
FIG. 7 a simplistic side view of a wheel according to the invention;
FIG. 8 a cross-section of a reinforcing unit; and
FIG. 9 a cross-section of another reinforcing unit.
DETAILED DESCRIPTION
With reference to the enclosed FIGS. 1 to 9 , an exemplary embodiment of a wheel 1 according to the invention will be discussed by way of its use in bicycles 100 .
FIG. 1 shows a bicycle 100 illustrated as a roadster or a racing bicycle with the front wheel 101 and the rear wheel 102 configured as wheels 1 according to the invention. The bicycle comprises a frame 103 , a handlebar 106 and a saddle 107 . The front wheel 101 and the rear wheel 102 are each provided with a plurality of spoke systems 3 . The rim 2 is connected with the hub 30 by means of spokes 4 . The front wheel 101 is presently provided with radial spoking while the rear wheel 102 is provided with spokes disposed at least in part tangentially at the hub 30 to allow the transmission of rotational force.
FIG. 2 shows a schematic illustration of a mountainbike as the bicycle 100 . The front wheel is retained sprung at a suspension fork 104 while a damper 105 is provided for damping the rear wheel. A disk brake 108 serves for braking.
FIG. 3 shows an enlarged cross-section of a wheel 1 according to the invention having a rim 2 and a spoke system 3 in the assembled state 10 .
In the hollow space area of the rim 2 , the concave rim base 13 is provided with a disk-type reinforcing unit 6 having a convex rim contact surface 12 and a concave outside surface 14 . The convex rim contact surface 12 is matched to the concave rim base 13 so as to allow on the one hand an optimum force transition from the reinforcing unit 6 to the rim base and on the other hand also an angular orientation of the reinforcing unit 6 relative to the rim base 33 . This ensures a particularly good angular orientation of the spoke 4 to the rim well 33 .
The spoke system 3 comprises a spoke nipple 5 and the spoke 4 . The spoke 4 comprises in an end region thereof an external thread that screws into an internal thread at the spoke nipple 5 . The radially outwardly end of the spoke nipple 5 is provided with a tool engagement point 27 where a tool can engage for rotating the spoke nipple 5 and tensioning the spoke 4 . The spoke nipple 5 may, for example, comprise a Torx drive or else an internal hexagon or an external hexagon. Other tool engagement points are likewise possible.
The spoke nipple 5 comprises a spherical head 26 with its hemispherical-type surface accommodated at a depression 15 having a concave nipple contact surface 16 . The hemispherical-type surface of the spherical head 26 forms a supporting area 5 a at which the spoke nipple 5 rests on the concave nipple contact surface 16 . The concave nipple contact surface 16 in combination with the convex surface or the convex supporting area 5 a of the spoke nipple 5 also allows an angular orientation of the spoke system 3 . The effective length of the spoke 4 does not change even in the case of an angular orientation.
The spoke nipple 5 plunges through a through hole 7 in the reinforcing unit 6 and through a spoke hole 28 in the rim 2 through the rim 2 so as to make the spoke nipple 5 project radially inwardly. This allows a compact rim with a hollow space of a height that may e.g. be low.
The inward end of the spoke nipple 5 is provided with a square 35 which a tool can engage for example for tensioning or readjusting a spoke system 3 . This considerably facilitates the performance of maintenance. While the system according to US 2003/0090141 A1 provides for first removing the tire to allow access to the interior of the rim, the spoke 4 in the present case can be tensioned at the square 35 or a tool contour.
While in the present exemplary embodiment the width 24 of the rim 2 is preferably between approximately 20 and 25 mm, it may basically be between 17 and 36 mm. The height 25 of the rim 2 from the rim well up to the rim flanges is presently somewhat over 20 mm and it may be noticeably larger depending on the configuration.
It can clearly be seen in FIG. 3 that the thickness 8 of the reinforcing unit 6 is in all the places less than the diameter 32 of the spoke 4 . In the case of double thickness spokes, the thickness of the reinforcing unit 6 may be smaller than that of the thinner part of the spoke 4 .
The thickness 8 of the reinforcing unit 6 and the thickness of the rim base 33 are matched to one another such that a particularly low total weight can be achieved overall. This is decisively also achieved by the fact that the reinforcing unit 6 is configured as a disk-type and does not extend into the spoke hole 28 of the rim 2 . The reinforcing unit 6 has a thickness 8 that is small enough so as to contribute to the total weight of the wheel 1 to a minor extent only.
FIG. 4 shows a schematic, perspective illustration of a reinforcing unit 6 , clearly showing the bent, disk-type structure with the through hole 7 . The reinforcing unit 6 has a thickness 8 that, apart from the central nipple accommodation 9 , is presently constant and corresponds to the maximum thickness 20 of the reinforcing unit 6 . The thickness 8 in the present exemplary embodiment is approximately 0.9 mm and may be somewhat thinner or thicker depending on the embodiment and the application. In particular, the thickness 8 of the reinforcing unit 6 is thinner than a maximum diameter of a spoke 4 of the associated spoke system 3 and in particular also thinner than the rim base 33 on which the reinforcing unit 6 rests. The reinforcing unit 6 may be referred to as a reinforcing disk. Places subjected to particular loads may be provided with a thicker and/or larger reinforcing unit 6 having a thickness and/or supporting surface enlarged e.g. by 10%, 25% or else 50%. In places subject to low loads the reinforcing unit 6 may be omitted or a thinner and/or smaller reinforcing unit 6 may be employed having a thickness and/or supporting surface that is reduced by e.g. 5%, 10% or else 25%.
The reinforcing unit 6 shows a convex rim contact surface 12 which in the state 10 installed as intended bears against the rim base 33 . The outside surface 14 of the reinforcing unit 6 is preferably oriented in parallel or at least approximately in parallel to the rim contact surface 12 . A through hole 7 is centrally disposed at the reinforcing unit 6 and provided to be surrounded by the nipple accommodation 9 . The nipple accommodation 9 is configured as a concave depression 15 on the outside surface 14 and comprises a concave nipple contact surface 16 . The nipple contact surface 16 shows a radius of curvature 22 that is clearly smaller than the radius of curvature 23 of the rim contact surface 12 or the outside surface 14 .
FIG. 5 shows a top view of the reinforcing unit 6 from FIGS. 3 and 4 . The reinforcing unit 6 is mirror-symmetrical and curved along a longitudinal axis 11 . The depression 15 of the nipple accommodation 9 is configured transverse to the longitudinal axis 4 along a direction 17 .
The reinforcing unit 6 has a length 19 in the peripheral direction of the rim 2 and a width 18 transverse thereto. The reinforcing unit 6 may be manufactured from an originally circular, flat disk. The reinforcing unit 6 shows a central through hole 7 having a diameter 31 that is slightly larger than is the outer diameter of the spoke nipple 5 that passes through in the assembled state 10 to also allow an angular orientation of the spoke 4 relative to the reinforcing unit 6 .
On the whole the spoke system offers two options for angular orientation. The reinforcing unit 6 may be angularly oriented relative to the rim 2 . Moreover an orientation of the angle of the spoke 4 by the reinforcing unit 6 is possible.
FIG. 6 shows a cross-section along the lines A-A from FIG. 5 . The reinforcing unit 6 shows at the rim contact surface 12 and at the outside surface 14 a curve each having a radius of curvature 23 . The radius of curvature 23 depends on the specific application and in the exemplary embodiment lies in a range between approximately 6 mm and 8 mm. The nipple accommodation 9 shows a narrower curve of the nipple contact surface 16 having a radius of curvature 22 that is noticeably smaller than the radius of curvature 23 . In the exemplary embodiment, the radius of curvature 22 is between approximately 2.5 mm and 4 mm and preferably it is not larger than half the radius of curvature 23 .
A maximum thickness 8 of the illustrated reinforcing unit 6 is presently approximately 0.9 mm. The minimum thickness 21 of the reinforcing unit 6 lies in a range of one third and two thirds of the maximum thickness 8 and is presently approximately 0.4 mm. Other reinforcing units 6 may be larger or smaller and thicker or thinner.
The distance 22 from the center of the nipple contact surface 16 is presently chosen such that the circle segment having the nipple contact surface 16 extends entirely within the outer contour of the reinforcing unit 6 . This means that the distance 29 plus the thickness 8 of the reinforcing unit 6 is larger than or the same size as is the radius of curvature 22 .
The fact that the spoke nipple 5 projects radially inwardly out of the rim 2 and the fact that the thin, disk-type structure is matched to the rim curvature, allow to provide a particularly lightweight wheel 1 that is still robust. Since both the reinforcing unit 6 and the spoke nipple 5 can orient themselves angularly, a wheel 1 may be provided that withstands large and also highly dynamic loads while having a low weight.
FIG. 7 shows a simplistic side view of a wheel 1 provided with both radially oriented spokes 4 a , very slightly tangentially oriented spokes 4 b , and somewhat more tangentially oriented spokes 4 c . Due to the spokes 4 b and 4 c oriented also with a tangential component, the transmission of rotational forces in accelerating and decelerating is better.
The rim base 33 shown schematically only is provided with different reinforcing units 6 a through 6 c for the different spokes 4 a through 4 c . The reinforcing units 6 a through 6 c differ from one another in at least one property and in particular in at least one dimension.
Preferably, the rim contact surface 12 of the reinforcing units 6 a to 6 c is configured in various sizes as a supporting surface on the concave rim base 33 so as to provide the spokes 4 b , 4 c subjected to higher loads with a larger surface for the transition of forces. It is also preferred for the thicknesses 8 a , 8 b and 8 c of the reinforcing units 6 a to 6 c to differ from one another. Preferably the thicknesses 8 b , 8 c of the spokes 4 b , 4 c are greater than is the thickness 8 a of the reinforcing unit 6 a.
It is also possible to provide the spokes subjected to little load such as e.g. the spoke 4 a with no reinforcing unit 6 a at all so that the spoke nipple rests immediately on the spoke hole 28 in the rim 2 . Then the quantity of spoke nipples 5 of the wheel 1 is higher than the quantity of reinforcing units 6 .
In all the configurations, a reinforcing unit 6 is provided for exactly one spoke nipple. This allows weight savings compared to reinforcing elements which retain and support two and more spoke nipples at one reinforcing element. These reinforcing elements retaining two and more spoke nipples need to be configured clearly larger and stronger so that their weight is considerably higher.
FIGS. 8 and 9 show two variations of reinforcing units 6 a and 6 b which differ in their dimensions. The reinforcing unit 6 a is configured thinner and the reinforcing unit 6 b is thicker. In both cases the maximum thickness is presently less than 2 mm and more than 0.5 mm each.
Variable configurations of the reinforcing units 6 allow for achieving a desired total weight of the wheel 1 . The rim wall thickness may be significantly reduced. In some or in several places e.g. in solely radially oriented spokes or in spokes subjected to low loads reinforcing units 6 may be dispensed with entirely. | A wheel for at least partially muscle-powered vehicles and two-wheeled vehicles includes a hub and a rim having a plurality of spoke holes and a plurality of spoke systems for connecting the hub with the rim. A spoke system includes a spoke and a spoke nipple. A reinforcing unit with a through hole between the rim and the spoke nipple is provided. The reinforcing unit is a disk-type and is configured curved about at least one longitudinal axis. The reinforcing unit has a convex inner rim contact surface for bearing against a concave orientation area of the rim matched thereto. The reinforcing unit has a concave outside surface at which a nipple accommodation is provided at a depression having a concave nipple contact surface with a narrower curvature for accommodating a matching, convex supporting area of the spoke nipple. | 1 |
BACKGROUND OF THE INVENTION
The present invention relates to a method and device for regulating a braking operation for an individual wheel on a vehicle equipped with a braking control system. The system comprises measuring means for monitoring wheel speed, an electronic unit, and a valve unit situated in the brake line for coupling the brake pressure medium to an individual wheel. In the method according to the invention, the braking pressure to the wheel is caused to vary in response to reference values for different control parameters, so that during the course of braking the wheel is affected during a number of braking control cycles, during which the wheel, by means of pressure alterations in the braking pressure medium, is retarded from a first rotational speed to a second lower rotational speed and is thereafter allowed to increase its rotational speed at a reduced braking pressure, so that at least one reference parameter sets off the next controlling cycle, the maximum braking capacity of the wheel on the appropriate road surface being reached and exceeded during the reduction of the wheel rotational speed from the first to the second value.
In braking, it is a well known problem that when the braking moment on a wheel becomes larger than the road moment which is the product of wheel radius and frictional force between wheel and road, the wheel will skid. The result of this may be that the braking capacity of the wheel is decreased simultaneously as steering capacity is wholly or partly lost.
The braking force which is obtained in the contact between wheel and substructure during braking is dependent on many factors, such as the nature of the substructure and the wheel, the speed of the vehicle, wheel loading, prevailing temperature etc. For each combination of such conditions the frictional conditions can be described by a characteristic graph in a coordinate system which defines braking force on the wheel as a function of the wheel slip. "Slip" in this case means the difference between the speed of the vehicle and the wheel in relation to the speed of the vehicle. By "wheel speed" is meant here, and in what follows, the rotational speed of the wheel. Characteristic for such a braking force graph is that braking force is present only when slip deviates from zero. With increasing slip, the braking force increases to a maximum, whereafter it diminishes once again. Graphs may also be plotted in the same coordinate system to show how the ability of a wheel to take up side forces varies with the slip. The ability to take up side forces is greatest when no slip prevails, and diminishes first slowly and then more and more rapidly with increasing slip. It is a generally accepted fact that the ability to take up side forces when the lag corresponding to the maximum on the braking force graph still has an acceptable value. To obtain optimal braking capacity it is therefore important to control the braking function at and in the vicinity of the maximum on the braking force graph. With braking pressure control it is also important to keep the braking pressure variations required for the braking function within acceptable limits in the respective braking circuits. This applies especially to pneumatic braking systems, since air consumption would otherwise be too great.
BRIEF DESCRIPTION AND OBJECT OF THE INVENTION
The primary object of the invention is to enable effective braking by utilizing the available frictional force between wheel and road better than before.
The method according to the invention is distinguished in that the acceleration of the wheel is measured and that a signal representing the maximum wheel acceleration is compared with a signal representing actual braking pressure increase for the purpose of determining the amount of braking pressure increase required over the braking pressure used during the acceleration in order to obtain optimum braking capacity between the vehicle wheel and the road surface, and that during the subsequent braking pressure increase a pressure regulating circuit controls increase of the braking pressure to the value determined by the maximum wheel acceleration. In this way information is obtained in advance of the next braking control cycle as to how great the pressure increase which will then be required and may be permitted for obtaining the best possible braking capacity.
In the braking control system for carrying out this method the electronic unit is arranged to control, in response to signals from the measuring means monitoring the wheel speed, the valve unit for alternately raising, lowering and maintaining the pressure at a constant level in the braking circuit of the wheel, whereat the wheel is caused alternately to be retarded or accelerated so that the maximum braking capacity of the wheel on the appropriate road surface is obtained, and the system is distinguished in that a module incorporated in the electronic unit and intended for calculating the pressure alteration comprises a pressure comparator which is arranged to compare a signal which is peak value followed in a peak value follower circuit and represents the acceleration of the wheel during a controlling cycle, with a signal corresponding to the current pressure increase.
BRIEF DESCRIPTION OF THE FIGURES
The invention will now be described more closely in the form of an example while referring to the accompanying drawings where
FIG. 1 shows a block diagram of a control system installed in a vehicle,
FIG. 2 shows in more detail the modules constituting the braking control system electronic unit,
FIG. 3 shows a graph of braking moment and road moment as a function of wheel slip and
FIG. 4 illustrates graphs (a)-(c) over wheel speed, wheel speed alterations and braking pressure variations for an individual wheel as a function of time during the course of braking.
DETAILED DESCRIPTION OF THE INVENTION
The braking control system shown as an example (see FIG. 1) is intended for a vehicle equipped with a pneumatic braking system with two braking circuits a and b, in which braking pressure is initiated by the vehicle driver operating a brake pedal c. The braking control system has the task of providing individual control for braking the respective wheels d in response to predetermined limiting values for slip and acceleration for the wheel during a braking operation. To achieve this, the braking control system comprises a number of separate means for each individual wheel d and a central module 4 common to the different wheels. The separate means for respective wheels d are mutually alike, for which reason the following description is limited to the construction and function of the braking control system for one wheel d.
A valve unit 6 is mounted in a brake line to an individual wheel d, and includes a valve for regulating braking medium flow to and from to the braking means of the wheel d, under the influence of signals from an electronic unit comprising the common central module 4 and a number of separate modules for each separate wheel d. The separate modules consist of a module 5 for wheel speed calculation, a module 3 for calculating the pressure increase and reduction in the brake line for the wheel d in question, and a valve regulating module 2.
For the inventive braking pressure control, it is necessary to obtain information on both the speed of the vehicle and of each individual wheel d during a braking operation. For measuring the wheel speed of each wheel there is provided a transducer 1 which generates an alternating voltage having a frequency proportional to the wheel speed, this voltage then being applied to the calculating module 5 associated with each wheel and containing a pulse shaper and a frequency doubler connected in series to each other, a constant pulse generator and a filter. The signal from the wheel speed transducer 1 is first converted in the pulse shaper incorporated in module 5 to square wave form, after which the frequency doubler senses each pulse flank or edge of the square wave and feeds out a series of short pulses, the frequency of which is converted in the pulse generator to a more suitable control variable, which in the present case means that the constant pulse generator supplies pulses with constant length and amplitude, i.e. constant voltage-time surface area, the integrated average value of which is proportional to the wheel speed. This average value is obtained in the subsequent filter which is of the low-pass type and contains two RC-branches and an amplifier, and a DC voltage signal corresponding to this value can be taken off from the filter output. This signal is designated wheel speed signal in the following description, and is applied to the calculating module 3.
Wheel speed signals from modules 5' associated with the front wheels of the vehicle are also applied to the central module 4 for calculating the vehicle speed, this module being arranged to feed reference signals to the calculating modules 3 for the respective wheels d. The circuits or stages in modules 2,3,5 and module 4 each comprise known basic elements with functions generally known in electronic technology, and therefore the following description is limited to only more closely defining the manner of connection and the coaction of the different circuits or stages in the apparatus according to the invention.
The wheel speed signal output from module 5 (FIG. 2) is fed within each module 3 to a wheel acceleration calculating stage 9 (FIG. 2), a wheel retardation calculating stage 10 and to a stage 11 for detecting wheel lag. Stages 9 and 10 are designed as differentiators, by differentiator being meant a filter circuit with differentiating action built up from known components around an operational amplifier. In these stages 9 and 10, with mutually somewhat different construction, the time derivative of the fed-in wheel speed signal is obtained so that the output signals from stages 9 and 10 will represent wheel acceleration and retardation, respectively, during wheel speed alterations. In the following description these output signals are designated acceleration and retardation signals.
The retardation signal is intended to be applied to a first retardation comparator 17 which compares this signal with a predetermined reference signal taken from the central module 4 and corresponding to the maximum permitted wheel retardation. When the greatest permitted wheel retardation is exceeded, the comparator 17 gives a signal which, via the valve regulating module 2, causes pressure reduction in the brake line by regulating the valve unit 6 connected to it, which contains an inlet valve 27 and an outlet valve 28, each of which is indicated in FIG. 2 by its respective magnet winding. The retardation signal from stage 10 is also supplied to a second retardation comparator 18 which senses heavily increased retardation. The comparators 17 and 18 are connected with each other across a diode 20, blocking the comparator 18 from causing continuous pressure reduction when a signal from comparator 17 is not present. Otherwise, the pressure reduction takes place step-wise under the influence of an output signal from comparator 17, a pulse generator 21 (to be described later) incorporated in module 2 generating constant pulses with a constant frequency during each control cycle for regulating the outlet valve 28.
The detector stage 11 for detecting wheel lag comprises a comparator which compares an instantaneous wheel speed signal from module 5 with a predetermined reference signal from the common central module 4. This reference signal is a signal voltage reduced by a resistance and representing the vehicle speed, varying in response to it so that the reference slip increases with low vehicle speed. The output of detector stage 11 is connected to an output on the first retardation comparator 17 so that pressure reduction cycles caused by stage 11 are analogous to those applied to comparator 17.
The acceleration signal from stage 9 is intended to cause a pressure increase in the relevant brake line for predetermined acceleration limit values, and for this purpose the signal is fed into an acceleration detector 12 and to a pressure comparator 13 by way of a peak value follower circuit 14. The detector 12 comprises two series connected comparators 12A and 12B, in which the instantaneous acceleration signal is compared with reference signals corresponding to predetermined acceleration values triggering pressure increase. A blocking diode is connected between the two comparators and reference signals are fed in from voltage dividers for each of the comparators. The reference signal for comparator 12B corresponds to a lower limit value for the wheel acceleration during a pulse braking operation, while the reference signal for comparator 12A corresponds to an acceleration which is normally attained during a braking operation. When a wheel accelerates, the lower predetermined acceleration limit is arrived at first, whereat detector 12 emits a signal closing valves 27,28 thereby causing maintenance of pressure in the brake line. The inlet valve opens either when acceleration drops below this lower limit, or when the higher, normal acceleration limit is reached, on the condition that the lag limit for the wheel is not reached. The comparator 12A, which after actuation acts as a bistable flipflop, is reset by a signal from either stage 11 or 17 on resetting to a pressure reduction cycle.
The necessary pressure increase in the braking circuit is calculated in the pressure comparator 13 by an acceleration signal from the acceleration calculating stage 9 being peak value followed in the peak value follower stage 14 and compared with a signal which represents the integrated value of control pulses for regulating the inlet valve 27 for the brake line of the appropriate wheel. These control pulses are fed from output 29A of stage 29 to input 16A of an integrating stage 16 in which the pulses are integrated, the output signals from stage 16 representing the pressure increase during a pressure increase cycle. The peak value follower stage 14 contains a voltage storing capacitor C14 and a blocking diode D14 which only enables signal passage when the instantaneous wheel acceleration signal exceeds the voltage already developed across the capacitor. Both the peak value follower stage 14 and the integrating stage 16 are arranged to be set to zero position (i.e. discharge) via their respective inputs 14B and 16C, respectively coupled to outputs 29B and 31C by control pulses to the outlet valve 28 for the brake line of the appropriate vehicle wheel.
The signal value stored in the capacitor C14 of peak value follower stage 14 represents the value to which the integrated value of the input pulses should rise for the braking capacity of the wheel against the road surface to be optimally utilized. This relationship between stored signal value and braking capacity is of fundamental importance in the principle of control according to the present invention and is therefore further clarified in the following functional description.
Apart from the above described braking pressure regulating stages 11,12,13,17 and 18, the calculating module 3 also comprises a time comparator 19 which, similar to the pressure comparator 13, is arranged to actuate the inlet valve 27 for increasing the braking pressure, while on the other hand stages 11,17 and 18 are arranged to actuate the outlet valve 28 for lowering the braking pressure. The inputs of the time comparator 19 are connected to a voltage divider and an RC-link with a high time constant. The capacitor in the RC-link is set to zero by pressure lowering pulses coupled to input 19B from output 29B and the comparator senses a definite time which has passed from the latest pressure reduction. When this interval of time has elapsed, the comparator causes increased pressure increase frequency in the pulse generator 21. The comparator 19 is connected with a gate incorporated in the central module 4, which gate receives output signals from the comparators 19 for all vehicle wheels. Only on the condition that output signals are coming in from all comparators 19 does this gate give an output signal for resetting the braking control system to its starting condition.
Stages 11,13,17,18 and 19 can operate either individually or in combination to provide output signals for altering braking pressure. Such an output signal is supplied to the pulse generator 21, which is also supplied with output signals from the acceleration detector 12 via a starting position stage 15 in connection with a wheel acceleration cycle. The pulse generator 21 is incorporated in the valve regulating module 2 and generates variable frequency valve signals. For this purpose the pulse generator contains a comparator having positive feedback for obtaining hysteresis, so that the comparator obtains two different reference levels. A capacitor 23 is connected to the negative input of the comparator, the capacitor being charged by control pulses to the valves 27,28 and being discharged by the pressure regulating stages 11, 13,17 and 19. During the charging phase, discharge of the capacitor 23 is blocked by a diode, and the voltage is thus increased to the upper reference level of the comparator, at which the comparator changes sign, breaking off the control pulse and thereby also charging of the capacitor 23.
The capacitor is discharged through a fixed resistance 24 in the pulse generator 21 and through the pressure regulating stages 11,13,17 and 19, discharging continuing until the lower reference level of the comparator is arrived at, when the comparator once again changes sign and charging starts in the manner described above. For discharge, the time between pulses is determined by the capacitor 23 in alternative coaction with the fixed resistance 24 and the resistances on the output side of the different pressure regulating stages 11,13,17,19 by the formation of RC-links with different time constants.
For pressure increase it is desirable under certain conditions to be able to provide high and low pulse frequencies, and for this purpose the pressure comparator 13 is arranged in such a way that the RC-links formed by the resistance on the output side of the pressure comparator and the capacitor 23 in the pulse generator 21, for an "O"-signal (low signal level) on the output of the comparator 13, give high pulse frequency, while for a "1"-signal (high signal level) the RC-link formed by the resistance 24 and the capacitor 23 gives considerably lower pulse frequency. With a pressure increase triggered by the time comparator 19, a pulse frequency which is lower than the normal frequency triggered by the pressure comparator is obtained for an O-signal while a 1-signal from the time comparator 19 does not actuate the pulse generator 21.
A pressure reduction signal to the pulse generator 21 triggered by the retardation comparator 17 and/or the lag detector 11 gives a pulse frequency which step by step reduces the pressure in the brake line.
Output signals from the detector stage 11 and the retardation comparator 17 are also supplied to the starting condition stage 15, which also receives output signals from the pressure comparator 13 and the retardation comparator 18. The starting condition stage 15 contains two separate circuits, of which one contains components for such control of the pulse generator 21 that this assumes starting position for sending a pulse gap on resetting from high to low pulse frequency, which under certain conditions is triggered by the pressure comparator 13. The retardation comparator 18 maintains starting position for a pulse gap in the pulse generator 21 during continuous pressure reduction. The other circuit in stage 15 is arranged to control the pulse generator in such a way that it assumes starting position for sending a pulse on switching to pressure reduction triggered by the detector stage 11 or the retardation comparator 17. If the lower acceleration limit is not arrived at during braking operation, the stage 11 or the comparator 17 also arranges for the pulse generator 21 to assume position for sending a pulse gap so that maximum time is obtained to the next pressure increase pulse.
According to the above, the pulse generator 21 is also supplied with a signal via the starting position circuit 15 from the acceleration detector 12 during the acceleration cycle, whereon an O-signal from the detector 12 causes a starting position for giving a valve pulse from the pulse generator 21, which means that the voltage across the capacitor 23 is kept at a constant level slightly below the lower resetting level of the detector. On a 1-signal from the detector 12, the valve pulse blocking ceases and the pulse generator 21 then generates the abovementioned pressure increase signals.
A valve regulating stage 29 for the inlet valve 27 is supplied with signals from the pulse generator 21, the acceleration detector 12 and the retardation comparator 17, or the lag detector stage 11, the signals being sensed by an AND-gate, the output signal of which is transferred via an OR-gate to a driving stage 32. The OR-gate also receives output signals from a maintenance circuit 25 comprised of an RS flip-flop which is set by 0-signals from the retardation comparator 17 or the lag detector 11 and from the gate in the central module 4. A 1-signal from the hold circuit 25 is generated by the gate when triggered by a normal braking function, which means that the inlet valve 27 is open.
The same signals fed to the regulating stage 29 are fed to a valve regulating stage 30 for the outlet valve 28, whereat signals from the retardation comparator 17 or the detector 11 are, however, inverted before feeding into an AND-gate. The output signals from this gate are inverted and supplied to a driving stage 31 for the outlet valve 28.
The control system according to the invention is automatically activated during a braking operation, when either the retardation or the slip of a braked wheel d exceeds predetermined reference values. The control principle applied to the control system is based on braking pressure and thereby braking moment being varied during a braking operation, so that the braking capacity of the wheel on the road surface is utilized to a maximum, i.e., so that the maximum road moment (the product of wheel-road surface frictional force and wheel radius) is exceeded during braking, whereafter the braking pressure is reduced and a new pressure increase is begun when the speed of wheel d is once again increased. In FIG. 3 both the braking moment M and the road moment B have been plotted diagrammatically as a function of the wheel slip λ during a control procedure according to the invention. From the FIGURE it may be seen that the braking moment M is varied so that the road moment B passes through its maximum value during each control cycle. At the beginning of the control cycle, the braking moment M is increased according to the graph section M I while slip increases, i.e., the rotation speed of the wheel diminishes. The road moment B simultaneously increases and passes its maximum B m . Thereafter the braking moment M is reduced according to the graph section M II while slip λ continues to increase, at least to begin with, simultaneously as the road moment B continues to decrease. Reduction of the braking moment M is discontinued at the level M o , which falls below the value of the road moment B m during the control cycle. By keeping M constant at the level M o , the wheel speed is increased, i.e., slip is decreased, simultaneously as the road moment once again increases and passes its maximum B m . Thereafter a new braking moment increase takes place at the beginning of the subsequent control cycle.
A closer study of the forces in action on a wheel during a braking operation can be made with the help of a moment equation about the centre of the wheel. This moment equation may be written in the following manner: ##EQU1## where
B = f.sub.B N R (2)
m = k P (3)
b = the road moment created by frictional force against road surface
M = the braking moment from wheel brakes
I = moment of inertia of the wheel
R = wheel radius
v = peripheral speed of the wheel
f.sub.B = coefficient of friction, road surface-tire
N = normal force, road surface-tire
k = proportionality constant relating pressure P in braking medium to braking moment M[Equation (3)]
It can be seen from FIG. 3 and equation (1) that during the increase of wheel rotational speed, the wheel acceleration reaches its greatest value when the difference between B and M is greatest, i.e. when B has the value B m and M has the value M o . This may be written: ##EQU2## or ##EQU3##
In the illustration of an actual pressure control cycle the graph portions M I and M II cling closely above the road moment graph B. The following approximation is therefore usable in this connection:
ΔB.sub.m = B.sub.m - M.sub.o = M.sub.m - M.sub.o = ΔM.sub.m (6)
Equation (4) may therefore be written: ##EQU4##
The braking medium pressure increase ΔP required for accomplishing this braking moment increase will thus be: ##EQU5##
Thus, by measuring the maximum wheel acceleration during spin-up of the wheel (i.e. the increase in speed of the wheel) it may be determined how great the unutilized road holding value ΔB m is.
Hereby is obtained in advance, before the braking medium pressure, and thereby also the braking moment M, is again increased, a measure of how great the braking moment increase ΔM m or the braking pressure medium increase ΔP m is, which can be allowed with safety for the road friction available at the moment, without the occurrence of skidding.
To compensate for braking hysteresis, an empirical relationship (proportionality) between the braking medium pressure and the wheel speed alteration is simply utilized. Hysteresis is furthermore proportional to the braking medium pressure. The pressure alteration ΔP h necessary for compensating hysteresis may be given thus: ##EQU6## where m = a proportionality constant relating speed alteration to pressure alteration.
The required total braking medium pressure increase can thus be stated as: ##EQU7##
For achieving a definite pressure increase in the line leading to a wheel an inlet valve is incorporated in a valve unit 6. The inlet valve has two states, either open with a free passage to the brake cylinder or closed with a completely restricted supply. Since the pressure increases approximately linearly with time during a pressure increase cycle for the greater part of the pressure interval, the inlet valve can be opened for a time proportional to the maximum value of the wheel acceleration, thereby obtaining the desired pressure increase. It is advantageous here to use valves which give good linearity in the pressure increase graph, independent of pressure level and pedal force.
Even before the pressure increase is initiated, information is obtained on the pressure increase calculated on the basis of the appropriate wheel load and the nature of the road surface, which makes it possible to increase the pressure quickly in one stage to a level where effective braking is obtained. The result is better utilization of road friction, and a reduction in the braking distance. A subsequent minor slow pressure increase compensates for minor friction alterations and compensates for the road moment alteration caused by the vehicle weight shift forward during braking. At a sudden larger alteration in friction a corresponding pressure alteration step is obtained immediately.
Because the valves in the valve units 6 need not be opened so often, their regulating frequency thus being diminished, lower air consumption is obtained. In most cases the pressure control will furthermore be completely independent of the wheel slip and be responsive only to acceleration and retardation of the wheel. This is advantageous, since the calculated slip limit may deviate from the value at maximum friction, although pressure reduction can alternatively take place when a definite slip or retardation limit is exceeded.
In that case the retardation comparator 17 and the slip detector 11 trigger stepwise pressure reduction through intermittent opening of the outlet valve 28. However, retardation usually increases so heavily during a braking operation that the second retardation comparator 18 is actuated, whereat pressure reduction is continuous while the outlet valve 28 is kept open. This pressure reduction is discontinued when the reference value falls below the reference level in comparator 18, whereafter pressure reduction can continue stepwise until the inputs to the retardation comparator 17 and the slip detector 11 drop below the reference levels applied to these comparators. Pressure reduction can also be discontinued by the acceleration comparator 12 reaching a first acceleration limit and thereafter sending a signal which blocks both valves 27, 28 and maintains the pressure in the brake line constant.
The pressure increase is triggered in one case, when measured acceleration drops below the lower acceleration limit, on condition that the upper normal acceleration limit has not been reached and that the wheel slip falls below a decided reference level. In another case, which is the most usual, the upper normal acceleration limit is also reached during a braking operation and then pressure increase is triggered, on the condition that slip is below its reference level.
The pressure increase by means of inlet valve 27 takes place with high pulse frequency to a level which is determined by the voltage stored in the capacitor in the peak value follower stage, corresponding to the maximum acceleration of the wheel. According to the above, a signal corresponding to the pressure increase is generated during a control cycle in the integrator stage 16, this signal being compared with the capacitor voltage at the input of the pressure comparator 13, which, in response to the comparison result, alternates between rapid and slow pressure increase. If pressure increase takes place during a longer time than the time determined by the time comparator 19 since the previous pressure reduction, the comparator changes sign and triggers quicker pressure increase, which is discontinued only when pressure reduction is once again triggered.
An example of the relationship between braking medium pressure and individual wheel speed v and speed alteration dv/dt during braking is more closely shown by graphs (a) - (c) of FIG. 4. During braking, the wheel is retarded and its speed is gradually reduced until, at v A in FIG. 4 graph (a), the permitted retardation r I is exceeded. The retardation comparator 17 then gives a signal for pressure reduction. The retardation comparator 18 simultaneously senses that retardation increases heavily, and therefore triggers a continuous pressure reduction. As a result of valve lag etc., this pressure reduction is delayed by the time interval Δt I . At v B retardation stops increasing, and therefore a signal is now given for closing the outlet valve. Closing takes place after a delay Δt 2 , whereafter the pressure is kept constant awaiting continued pulsed pressure reduction. As a result of the reduction in braking moment due to lowering of pressure, the wheel begins to accelerate and exceeds, at v C , the lower acceleration limit a I , whereat pressure is kept constant and the circuitry prepares for a pressure increase. The upper acceleration limit a II is exceeded at v D , and, as soon as this limit is passed, pressure increase will be initiated, since the wheel slip has been reduced to the value λ ref . The wheel acceleration continues to increase and reaches at v E its greatest value during the increase of wheel rotational speed. The magnitude of the acceleration achieved at this point determines how great the coming pressure increase needs to be. When the slip value drops below λ ref at point v F , pressure increase is initiated, and begins after a delay Δt 3 . The pressure is thereafter increased in rapid steps to a level determined by the value of the acceleration in point v E . Said level is attained at v G , whereafter a slow further pressure increase takes place for compensating i.a. the forward weight shift of the vehicle. The permitted retardation value r I is exceeded at v H , whereat the heavily increasing retardation triggers continuous pressure reduction with a delay Δt 4 in the same way as at v A . The retardation increase ceases at v I , whereat the outlet valve is closed after a delay Δt 5 , and the pressure is thereafter kept constant to allow the wheel to increase its speed once again. The lower acceleration limit a.sub. I is exceeded at v J , whereat a pressure increase is prepared for (cf. at v C ). This time the upper acceleration limit a II is not exceeded, but the maximum acceleration is attained at v K . When acceleration thereafter drops below the lower acceleration limit a I , pressure increase is triggered, and is begun after the delay Δt 6 . The pressure is thereafter quickly increased by a value corresponding to the maximum acceleration measured at v K , although the pressure increase never takes place with less than a certain minimum value.
In the case illustrated here, pressure increase between v F and v G takes place by the pressure being pulsed with constant steps. It is however also possible to increase the pressure in one single step. It is just as possible to replace the slow pressure increase between v G and v H with a continuous pressure raise, whereat the valve is allowed to have a certain leakage. | A method and a device for regulating a vehicle wheel braking cycle. The braking pressure is caused to vary in response to control parameters, causing the wheel to decelerate and accelerate in an alternating fashion. During acceleration the value of acceleration is measured, and a signal representing the maximum acceleration is compared with a braking pressure signal for the purpose of determining the amount of pressure increase needed over the braking pressure used during the acceleration. The braking pressure is then increased to the value determined by the maximum wheel acceleration. | 1 |
CROSS-REFERENCE TO RELATED APPLICATION
This application claims priority to Korean Patent Application No. 2002-64641, filed on Oct. 22, 2002.
TECHNICAL FIELD
The present invention relates to a phase edge phase shift mask, and more particularly, to a phase edge phase shift mask enforcing a width of a field gate image located in a field region of a semiconductor substrate and a fabrication method thereof.
BACKGROUND
The use of a quartz mask board with the use of chromium for exposing a semiconductor substrate has been determined to cause optical interference between neighboring patterns with reduced design rules of a semiconductor device, thereby making it difficult to obtain desirable pitch sizes.
As a substitute, a phase shift mask has been proposed which implements precise and detailed patterns by reducing optical interference between the neighboring patterns on the semiconductor substrate with the use of chromium and molybdenum on the quartz mask board. A current trend is to use more than one phase-shift mask to obtain desired sizes as required by tighter design rules. In addition, a phase edge phase shift mask and a masking technique used in combination with a phase mask for exposing a semiconductor device has been determined to be beneficial.
For instance, a conventional phase edge phase shift mask technique is described in U.S. Pat. No. 5,807,649. With this process, two masks are used to form the same patterns (such as gate electrodes) on a semiconductor substrate. The two masks are composed of a phase shift mask and a trim mask.
Generally, a phase shift mask defines a predetermined portion of a photoresist image overlapping an active region of the semiconductor substrate by using shifters for shifting a phase of photo light.
Trim patterns on the trim mask form an entire shape of the photoresist image extended to a field region to protect the defined predetermined portion of the image from photo exposure. The photoresist image is a pattern made to form a gate pattern.
However, if an interval between the patterns is very narrow on the trim mask, the trim patterns are likely to contain defects that are detected during a checking process after the trim mask has been fabricated.
FIG. 1 a is a portion of rough diagram of a phase shift mask, according to a conventional phase edge phase shift mask. Referring to FIG. 1 a, the phase shift mask ( 10 ) has two shifters ( 20 , 20 - 1 ). The two shifters ( 20 , 20 - 1 ) are phase shift regions where light can be transmitted and separated by a predetermined interval ( 1 S) on the phase shift mask ( 10 ).
Light passing through one of the two shifters ( 20 , 20 - 1 ) has a 180-degree phase difference compared to light passing through the other shifter. The phase shift mask ( 10 ) is formed by the two shifters ( 20 , 20 - 1 ) and a dark portion ( 15 ). The dark portion is formed using chromium for defining the shifters.
FIG. 1 b is a rough image pattern of a phase shift mask formed on a semiconductor substrate, according to a conventional phase edge phase shift mask. Referring to FIG. 1 b, the phase shift mask ( 10 ) of FIG. 1 a overlaps an active region ( 27 ) on a semiconductor substrate ( 25 ), wherein the semiconductor substrate ( 25 ) is coated with a photoresist ( 29 ). And, open regions ( 31 , 33 ) corresponding to the shifters ( 20 , 20 - 1 ) of FIG. 1 a are formed on the semiconductor substrate ( 25 ).
The active region ( 27 ) is depicted by dotted lines to illustrate that the region is overlapped with the shifters ( 20 , 20 - 1 ) of FIG. 1 a, and the semiconductor substrate ( 25 ) is divided into several areas ( 29 , 31 , and 33 ), including area ( 29 ) with the photoresist, and areas ( 31 , 33 ) without the photoresist, corresponding to the shifters ( 20 , 20 - 1 ) of FIG. 1 a.
FIG. 1 c is a portion of rough diagram of a trim mask, according to a conventional phase edge phase shift mask. Referring to FIG. 1 c, the trim mask ( 35 ) is overlapped by the two shifters ( 20 , 20 - 1 ) of FIG. 1 a. The two shifters ( 20 , 20 - 1 ) formed on the trim mask ( 35 ) are depicted by dotted lines, but the two shifters ( 20 , 20 - 1 ) are not actually formed on the trim mask ( 35 ).
The trim mask ( 35 ) is divided into trim patterns ( 40 , 41 , 37 , and 37 - 1 ) where light can not be transmitted, and a transparent region ( 39 ) where light can be transmitted. Preferably, the trim patterns are subdivided into three regions: a first trim pattern ( 40 ) having a predetermined width of 4W, and formed between the two shifters ( 20 , 20 - 1 ); a second trim pattern ( 41 ) having a predetermined dimensions of 5W and 8W in the vertical/horizontal direction, respectively, and formed outside regions composed of the shifters ( 20 , 20 - 1 ); and third trim patterns ( 37 , 37 - 1 ) having the same width of 3W and overlapping the shifters ( 20 , 20 - 1 ), and the third trim patterns ( 37 , 37 - 1 ) are in contact with the second trim pattern ( 41 ).
The second trim pattern ( 41 ) is positioned away from a right boundary of the shifter ( 20 - 1 ) by a predetermined distance of 6W, and the third trim pattern ( 37 - 1 ) is positioned inside and away from the right boundary of the shifter ( 20 - 1 ) by a predetermined distance of 7W.
In other words, the second trim pattern ( 41 ) and the third trim pattern ( 37 - 1 ) are positioned away from the right boundary of the shifter ( 20 - 1 ) in opposite directions of one other, thereby forming a notch structure at a check point ( 1 P).
The notch structure is a defect that can be detected at the check point ( 1 P) in an inspection step after the trim mask ( 35 ) is fabricated. In other words, if a width of the notch structure is out of specification as compared to the tolerances as defined by a design rule at the check point ( 1 P), an inspection process detects the notch structure as a defect.
Further, a portion of the notch structure overlaps a portion of the photoresist ( 29 ) of FIG. 1 b. And, if light is transmitted through the portion of the notch structure that overlaps the photoresist of the trim mask ( 35 ) during a photo exposure process, an unwanted field gate image (not shown) is formed by sensitizing the photoresist ( 29 ) on the semiconductor substrate ( 25 ) of FIG. 1 b.
FIG. 1 d is a rough image pattern of a trim mask formed on a semiconductor substrate, according to a conventional phase edge phase shift mask. Referring to FIG. 1 d, the trim mask ( 35 ) of FIG. 1 c forms rough images ( 40 - 1 , 41 - 1 ). The rough image ( 40 - 1 ) has a predetermined width of 4W-1, and overlaps the active region ( 27 ). The rough image ( 41 - 1 ) includes a vertical side portion having a predetermined width of 8W-1, and a horizontal portion having a predetermined height of 5W-1 on the semiconductor substrate ( 25 ).
The rough image ( 41 - 1 ) is formed when light passes through the notch structure on the trim mask ( 35 ) of FIG. 1 c during an exposure process. Thus, the rough image ( 41 - 1 ) can be transferred to a gate having a very narrow width causing an increase in the resistance and drops in the current driving capability in a gate. In other words, the performance of the gate on the semiconductor device deteriorates.
Therefore, a need exists to enforce a width of a field image to improve the performance of a gate on a semiconductor device.
SUMMARY OF THE INVENTION
The present invention provides a method for enforcing a width of a field gate image located in a field region of a semiconductor device. According to an embodiment of the present invention, the method is provided to reduce the photoresist loss during a photo exposure process by preventing the formation of a notch structure formed between trim patterns on a trim mask by forming a region with a predetermined width between shifters and a second trim pattern on a field region, and forming a third trim pattern for protecting the predetermined region, thereby enforcing an image width on the field region.
According to another embodiment of the present invention, a method is provided to reduce photoresist loss during a photo exposure process by preventing the formation of a notch structure between trim patterns within a trim mask. The method comprises the steps of coinciding a side of a second trim pattern on a field region with boundaries of shifters opposite to the second trim pattern, coinciding selected sides of a third trim pattern with the boundaries, and forming a dummy pattern with a predetermined width on an opposite side of the second trim pattern adjacent to the shifters, thereby enforcing an image width on the field region.
According to another embodiment of the present invention, a phase edge phase shift mask comprises a plurality of shifters and an opaque region for defining the shifters; and a trim mask comprises first, second, and third trim patterns overlapped with the phase shift mask. The first trim pattern corresponds to an opaque region between the shifters, and the second trim pattern is connected to the first trim pattern separated from at least one shifter by a predetermined width. The third trim pattern is overlapped with the shifters and is adjacent to selected sides of the first and the second trim patterns.
It is desirable that a notch structure is removed by the third trim pattern being in contact with the first and the second trim patterns, and a separated region having a predetermined width between the shifts and the first trim pattern and the second trim pattern is protected by the third trim pattern. It is also desirable that the third trim patterns contact the first and the second trim patterns to prevent the formation of a notch structure.
It is more desirable that the shifters are phase shift regions formed to change a phase of incident light, and further have a dummy pattern attached to sides opposite to the selected sides on one side of the second trim pattern.
According to another embodiment of the present invention, a phase edge phase shift mask comprises the steps of: forming a plurality of shifters comprising phase shift regions; forming an opaque region for defining the shifters; preparing a phase shift mask comprising the shifters and the opaque region; forming a first trim pattern corresponding to the opaque region between the shifters; forming a second trim pattern separated from the shifters by a predetermined width; connecting the first trim pattern with the second trim pattern; forming a third trim pattern within boundaries defining the shifters and in contact with selected sides of the first and the second trim patterns; preparing a trim mask comprising the first, second, and the third trim patterns; and preparing the phase edge phase shift mask using the phase shift mask and the trim mask.
According to another embodiment of the present invention, a phase edge phase shift mask comprises a plurality of shifters; a phase shift mask comprises an opaque region for defining the shifters; and a trim mask comprising of a first to a third trim patterns and a dummy pattern overlapped with the phase shift mask. The first trim pattern corresponds to an opaque region between the shifters, and the second trim pattern is connected to the first trim pattern and is adjacent to at least one shifter. The dummy pattern is attached to a side opposite to a second trim pattern side faced with the shifters. The third trim pattern is adjacent to selected sides of the first and the second trim patterns by overlapping with the shifters.
It is desirable that the third trim pattern removes a notch structure by being adjacent to the first and the second trim patterns, and protects separated regions having a predetermined width between the first and the second trim patterns. The shifters are phase shift regions formed to change a phase of incident light.
According to another embodiment of the present invention, a method of fabricating a phase edge phase shift mask, comprises the steps of: forming a plurality of shifters comprising phase shift regions; forming an opaque region for defining the shifters; preparing a phase shift mask comprising the shifters and the opaque region; forming a first trim pattern corresponding to the opaque region between the shifters; forming a second trim pattern adjacent to the shifters; forming a dummy pattern on a side opposite to a second trim side adjacent to the shifters; connecting the first trim pattern with the second trim pattern; forming a third trim pattern in contact with selected sides of the first and the second trim patterns by being overlapped within the shifters; preparing a trim mask where the first to the third trim patterns are formed; and preparing the phase edge phase shift mask composed of the phase shift mask and the trim mask.
According to another embodiment of the present invention, a method of fabricating a phase edge phase shift mask enforcing a width of a field gate image comprising the steps of: forming a plurality of shifters comprising phase shift regions; forming an opaque region for defining the shifters; preparing a phase shift mask comprising the shifters and the opaque region; forming a first trim pattern corresponding to the opaque region between the shifters; forming a second trim pattern adjacent to the shifters; forming a dummy pattern on an opposite side of the second trim pattern side adjacent to the shifters; connecting the first trim pattern with the second trim pattern; forming a third trim pattern in contact with selected sides of the first and the second trim patterns by overlapping the selected sides within the shifters, and wherein the third trim pattern is disposed within an outer boundaries of the shifters; preparing a trim mask comprising the first, second, and the third trim patterns; and preparing the phase edge phase shift mask using the phase shift mask and the trim mask.
These and other embodiments, features, aspects, and advantages of the present invention will be described and become apparent from the following detailed description of the preferred embodiments when read in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 a is a portion of a rough diagram of a phase shift mask, according to a conventional phase edge phase shift mask.
FIG. 1 b is a rough image pattern of a phase shift mask formed on a semiconductor substrate, according to a conventional phase edge phase shift mask.
FIG. 1 c is a portion of rough diagram of a trim mask, according to a conventional phase edge phase shift mask.
FIG. 1 d is a rough image pattern of a trim mask formed on a semiconductor substrate, according to a conventional phase edge phase shift mask.
FIG. 2 a is a phase edge phase shift mask illustrating a portion of rough diagram of a trim mask overlapped by a plurality of shifters, according to an embodiment of the present invention.
FIG. 2 b is shows a phase edge phase shift mask illustrating rough images formed by a phase shift mask and a trim mask on a semiconductor substrate, according to an embodiment of the present invention.
FIG. 2 c illustrates a portion of wiring diagram formed by a conventional phase edge phase shift mask.
FIG. 2 d illustrates an image picture after photo simulation on a conventional phase edge phase shift mask.
FIG. 2 e illustrates a portion of wiring diagram formed by the phase edge phase shift mask, according to an embodiment of the present invention.
FIG. 2 f illustrates an image picture after photo simulation, according to an embodiment of the present invention.
FIG. 3 a is a phase edge phase shift mask illustrating a trim mask overlapped by a plurality of shifters, according to another embodiment of the present invention.
FIG. 3 b illustrates rough images formed by a phase shift mask and a trim mask on a semiconductor substrate, according to another embodiment of the present invention.
FIG. 3 c illustrates a portion of wiring diagram formed by a phase edge phase shift mask, according to another embodiment of the present invention.
FIG. 3 d illustrates an image picture after photo simulation, according to another embodiment of the present invention.
DESCRIPTION OF PREFERRED EMBODIMENTS
The present invention will now be described more fully hereinafter with reference to the accompanying drawings, in which preferred embodiments of the invention are shown. This invention may, however, be embodied in different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. In the drawings, the thickness of layers and regions are exaggerated for clarity.
FIG. 2 a is an examplary phase edge phase shift mask illustrating a portion of a rough diagram of a trim mask overlapped by a plurality of shifters, according to an embodiment of the present invention. Referring to FIG. 2 a, the trim mask ( 100 ) comprises first and second trim patterns ( 150 , 160 ), which are overlapped by two shifters ( 105 ) having the same width of 110W, and third trim patterns ( 120 , 140 ).
A phase mask is comprises two shifters ( 105 ), transparent regions, and an opaque region (not shown) for defining the two shifters. Light passes through one of the two shifters ( 105 ) at a 180-degree phase difference compared to light passing through the other shifter.
The first trim pattern ( 150 ) of the first trim mask ( 100 ) has a predetermined width of 150W corresponding to an active region (not shown), and the second trim pattern ( 160 ) includes a vertical side portion having a predetermined width of 210W and a horizontal base portion having a predetermined height of 230W corresponding to a field region (not shown). The field region is the region outside the two shifters ( 105 ) corresponding to an active region.
The third trim patterns ( 120 , 140 ) of the trim mask ( 100 ) have of 130W and 170W, respectively, to prevent the formation of a notch structure as shown in FIG. 1 c at a check point ( 3 P). Thus, the notch structure is prevented from forming because the third trim patterns ( 120 , 140 ) substantially cover a surface of the shifters ( 105 ). Preferably, the third trim pattern ( 120 ) extends over a predetermined region 190W-1, which is a predetermined distance between the shifters ( 105 ) and the horizontal base portion of the second trim pattern ( 160 ), to connect with the horizontal base portion of the second trim pattern ( 160 ), and the third trim pattern ( 140 ) extends over the predetermined distance 190W-1 to connect with the horizontal portion of the second trim pattern ( 160 ) and to connect with the vertical portion of the second trim pattern ( 160 ) covering a predetermined distance of 190W, which is a predetermined distance between the right most shifter ( 105 ) and a side wall of the vertical portion of the second trim pattern ( 160 ) facing the shifters and the third trim pattern ( 140 ).
The side portions of the third trim patterns ( 120 , 140 ) that are not in contact with the first trim pattern ( 150 ) and the second trim pattern ( 160 ) are positioned inside and at a predetermined distance of 100W from a top boundary of the shifters ( 105 ). The first trim pattern ( 150 ) is disposed between the two shifters ( 105 ) and is connected the horizontal base portion of the second trim pattern ( 160 ) formed outside the two shifters ( 105 ).
FIG. 2 b illustrates rough images formed by a phase shift mask and a trim mask on a semiconductor substrate, according to an embodiment of the present invention. Referring to FIG. 2 b, the rough images ( 150 - 1 , 160 - 1 ) are formed by two consecutive photo exposure processes (not shown) on a semiconductor substrate ( 200 ) coated with a photoresist. In other words, the rough images ( 150 - 1 , 160 - 1 ) are formed by using two shifters ( 105 ) of FIG. 2 a depicted by dotted lines and a trim mask ( 100 ).
Through the photo exposure process, the rough images ( 150 - 1 , 160 - 1 ) are formed. Rough image ( 150 - 1 ) has a predetermined width of 150W-1 and overlaps an active region ( 220 ). The rough images ( 150 - 1 , 160 - 1 ) are connected on the field region ( 240 ). Rough image ( 160 - 1 ) includes a vertical side portion having a predetermined width of 210W-1, and a horizontal base portion having a predetermined height of 230W-1.
Compared to FIG. 1 d, the rough image ( 160 - 1 ) has been enforced by removing a notch structure on the trim mask ( 100 ) of FIG. 2 a and by covering the horizontal/vertical separation between the second trim pattern ( 160 ) from the shifters ( 105 ) by predetermined widths of 190W and 190W-1, respectively, with the third trim patterns.
Further, the rough images ( 150 - 1 , 160 - 1 ) connected to the field region ( 240 ) on the semiconductor substrate ( 200 ) illustrate the photoresist loss by a photo exposure process.
FIG. 2 c illustrates a portion of wiring diagram formed by a conventional phase edge phase shift mask. Referring to FIG. 2 c, the wiring diagram shows a portion of the phase edge phase shift mask where a second trim pattern ( 53 ) within a trim mask (not shown) is separated from a third trim pattern ( 49 ) by a predetermined width of 9W between shifters ( 45 ) of a phase shift mask (not shown).
In addition, the wiring diagram ( 43 ) can be divided into an upper surface (A) and a lower surface (B) by an upper side of the second trim pattern ( 53 ).
In the wiring diagram ( 43 ), since the second/third trim patterns ( 53 , 49 ) are separated at the lower surface (B) by a predetermined width of 9W, a region opened to the shifters ( 45 ) of the phase shift mask is opened again during photo exposure (not shown) with the use of the trim mask, thereby the photoresist (not shown) protected by the second trim pattern ( 53 ) may be lost.
With the loss of the photoresist, an image width formed on field regions ( 47 , 51 ) is narrower than a predetermined wiring width. Also, a gate width is reduced after an etching process, which increases the resistance and drops the current driving capability of a gate.
FIG. 2 d illustrates an image picture after photo simulation on a conventional phase edge phase shift mask. Referring to FIG. 2 d, FIG. 2 d illustrates a simulation image ( 55 ). It is expected that a photoresist pattern is formed by using the phase edge phase shift mask (not shown) of FIG. 2 c on a semiconductor substrate (not shown).
The photo simulation has been performed under the operating conditions of 200 nm defocus and 20 nm misalignment. The phase edge phase shift mask has the second/third trim patterns ( 53 , 49 ) separated by a predetermined width of 9W as in FIG. 2 c at a check point ( 4 P).
Since a photo exposure (not shown) is performed through the separated region, the simulation image ( 55 ) is created in the check point ( 4 P) owing to the loss of a photoresist protected by the second trim pattern ( 53 ). The simulation image ( 55 ) is nearly disconnected by two photo exposure processes, and the photoresist does not perform a role as an etching mask in a subsequent etching process.
FIG. 2 e illustrates a portion of wiring diagram formed by the phase edge phase shift mask, according to an embodiment of the present invention. Referring to FIG. 2 e, the wiring diagram ( 260 ) shows a portion of the phase edge phase shift mask where shifter ( 280 ) of a phase shift mask (not shown) overlaps a second/a third trim patterns ( 320 , 360 ) of a trim mask (not shown).
Furthermore, the wiring diagram ( 260 ) can be conveniently divided into an upper surface (A) and a lower surface (B) by an upper side portion of the second trim pattern ( 360 ). The shifter ( 280 ) is separated from the second trim pattern ( 360 ) by a predetermined width of 250W, and a photoresist (not shown) remains in a separated region.
The third trim pattern ( 320 ) protects the separated region in the lower surface (B) in the wiring diagram ( 260 ), and is adjacent to a boundary line of the second trim pattern ( 360 ).
In the wiring diagram ( 260 ), the photoresist remaining by the shifter ( 280 ) obtains a better photoresist image because a left side of the photoresist has been enforced by cutting off photo light with use of the third trim pattern ( 320 ) on the trim mask during a photo exposure process.
FIG. 2 f illustrates an image picture after photo simulation, according to an embodiment of the present invention. Referring to FIG. 2 f, the simulation image ( 380 ) illustrates an expected photoresist pattern being formed by using the phase edge phase shift mask (not shown) of FIG. 2 e on a semiconductor substrate (not shown).
In other words, if the phase edge phase shift mask has the second trim pattern ( 360 ) and the shifter ( 280 ) separated by a predetermined width of 250W, as shown in FIG. 2 e at a check point ( 5 P), a photoresist is enforced because the third trim pattern ( 320 ) protects a separated region. Therefore, it is possible to create the simulation image ( 380 ) on a field region in the check point ( 5 P).
The simulation image ( 380 ) shows that the photoresist on a left side is enforced without losing an upper part of the photoresist as compared to the simulation image ( 55 ) of prior art of FIG. 2 d.
And, the simulation image ( 380 ) performs a better role as an etching mask than the prior art for a subsequently proceeding etching process (not shown). The photo simulation has been performed under operating conditions of 200 nm defocus and 20 nm misalignment.
FIG. 3 a illustrates an exemplary trim mask ( 400 ) overlapped by a plurality of shifters, according to another embodiment of the present invention. Referring to FIG. 3 a, the trim mask ( 400 ) comprises first and second trim patterns ( 450 , 480 ), which are overlapped by two shifters ( 405 , 440 ) having predetermined widths of 410W and 470W, respectively, third trim patterns ( 420 , 460 ), and a dummy pattern ( 500 ).
The phase mask is comprises two shifters ( 405 , 440 ), transparent regions, and an opaque region (not shown) for defining the shifters. Light passing through the shifter ( 405 ) has a 180-degree phase difference compared to light passing through the shifter ( 440 ), wherein the shifters are separated at a regular interval.
The first trim pattern ( 450 ) of the trim mask ( 400 ) has a predetermined width of 450W and corresponds to an active region. The second trim pattern ( 480 ) includes a vertical side portion having a predetermined width of 510W and a horizontal base portion having a predetermined height of 530W corresponding to a field region.
The first trim pattern ( 450 ) is positioned between the two shifters ( 405 , 440 ), and is connected to the second trim pattern ( 480 ) formed outside the two shifters ( 405 , 440 ) having a predetermined width of 450W. The field region indicates a region outside the two shifters ( 405 , 440 ).
Moreover, the trim mask ( 400 ) has the second trim pattern ( 480 ) adjacent to the two shifter, and attaches the third trim patterns ( 420 , 460 ) having predetermined widths of 430W and 470W, respectively, and to the first pattern ( 450 ) to prevent the formation of a notch structure similar to one shown in FIG. 1 c.
The third trim patterns ( 420 , 460 ) are positioned within the two shifters ( 405 , 440 ). Preferably, the third trim patterns ( 420 , 460 ) are disposed by a predetermined width of 400W from a top boundary of the shifters ( 405 , 440 ).
The trim mask ( 400 ) has a dummy pattern ( 500 ) adjacent to an opposite side of a second trim pattern ( 480 ) side that faces the two shifters ( 405 , 440 ), and the dummy pattern ( 500 ) has a vertical side portion having a predetermined width of 490W and a horizontal base portion having a predetermined height of 490W-1.
The formation of the dummy pattern ( 500 ) enforces a photoresist image width (not shown) of a field region decreasing in check points ( 6 P, 7 P) by a photo exposure process (not shown), and prevents the reduction of the image width of the second trim pattern ( 480 ) because the dummy pattern ( 500 ) and the two shifters ( 405 , 440 ) are adjacent to the second trim pattern ( 480 ).
FIG. 3 b illustrates rough images formed by a phase shift mask and a trim mask on a semiconductor substrate, according to another embodiment of the present invention. Referring to FIG. 3 b, the rough images ( 450 - 1 , 660 ) are formed in a consecutive photo exposure of a semiconductor substrate ( 600 ) coated with a photoresist, by using a phase shift mask (not shown) with the shifters ( 405 , 440 ) depicted by dotted lines and the trim mask ( 400 ) of FIG. 3 a.
In addition, the rough images ( 450 - 1 , 660 ) are formed. Rough image ( 450 - 1 ) has a predetermined image width of 450W-1 and overlaps an active region ( 620 ), and rough image ( 660 ) includes a vertical side portion having a predetermined width of 550W and a horizontal base portion having a predetermined height of 570W on a field region ( 640 ). In addition, rough images ( 450 - 1 , 660 ) are connected to the field region ( 640 ).
Comparing to FIG. 1 d to FIG. 3 a, the rough image ( 660 ) has a enforced image width, by preventing the formation of a notch structure and attaching a dummy pattern ( 500 ) within the trim mask ( 400 ). Rough images ( 450 - 1 , 660 ) and the field region ( 640 ) on the semiconductor substrate ( 600 ) illustrates the loss of a photoresist by a photo exposure process.
FIG. 3 c illustrates a portion of wiring diagram formed by a phase edge phase shift mask, according to another embodiment of the present invention. Referring to FIG. 3 c, in the wiring diagram ( 690 ), shifter ( 700 ) on a phase shift mask (not shown) is overlapped with a second and a third trim patterns ( 800 , 740 ) on a trim mask (not shown), and the wiring diagram shows a portion of the phase edge phase shift mask including a dummy pattern ( 780 ) attached to the second trim pattern ( 800 ).
Furthermore, the wiring diagram ( 690 ) can be conveniently divided into an upper surface (A) and a lower surface (B) by an upper side portion of the second trim pattern ( 800 ).
In the lower surface (B) of the wiring diagram ( 690 ), the shifter ( 700 ) and the third trim pattern ( 740 ) are in contact with the second trim pattern ( 800 ), and the shifter ( 700 ) is shown outside the third trim pattern ( 740 ) in the upper surface (A) of the wiring diagram ( 690 ).
The dummy pattern ( 780 ) is in contact with a side of a second trim pattern ( 800 ) that is opposite to the side facing the shifters ( 700 ).
FIG. 3 d illustrates an image picture after photo simulation, according to another embodiment of the present invention. Referring to FIG. 3 d, a simulation image ( 820 ) illustrates it is expected that a photoresist pattern is formed by using the phase edge phase shift mask (not shown) of FIG. 3 c on a semiconductor substrate (not shown).
In the phase edge phase shift mask, if the shifter and the third trim pattern are adjacent to the second trim pattern, as shown in FIG. 3 c, in a check point ( 8 P) and a dummy pattern is attached to one side of the second trim pattern, a photoresist is enforced by the third trim pattern and the dummy pattern. Therefore, the simulation image ( 820 ) can be formed on a field region at the check point ( 8 P).
The simulation image ( 820 ) shows a photoresist that is enforced to the right without losing an upper part of the photoresist as compared to the simulation image ( 55 ) as shown in FIG. 2 d of the prior art. Thus, the simulation image ( 820 ) performs a better role as an etching mask for a subsequent etching process (not shown).
The photo simulation was performed under the operating conditions of 200 nm defocus and 20 nm misalignment.
The embodiments of the present invention use a phase edge phase shift mask to prevent a notch structure from forming between trim patterns and to protect a region formed by separating the shifters from the second trim pattern by using a third trim pattern. Further, the image of FIG. 3 d illustrates a enforce width of an image of FIG. 2 d by attaching a dummy pattern to the second trim pattern.
Accordingly, the present invention provides a phase edge phase shift mask for reducing photoresist loss during a two exposure processes by controlling overlap intervals between shifters on a phase shift mask and first to third trim patterns on a trim mask, and preventing the formation a notch structure between trim patterns on the trim mask. As a result, the phase edge phase shift mask increases design performance by improving the current driving capability of a semiconductor device.
While the present invention has been particularly shown and described with reference to preferred embodiments thereof, it will be understood by those of ordinary skill in the art that various changes in form and detail may be made therein without departing from the spirit and scope of the present invention as defined by the following claims. | A phase edge phase shift mask and a fabrication method thereof for enforcing a width of a field gate image located on a field region, which is weakened by a two exposure process, by using a phase shift mask and a trim mask on a semiconductor substrate, and enforcing a width of the field gate image to maximize a current driving capability of the semiconductor device. | 6 |
BACKGROUND OF THE INVENTION
The present invention relates to an electrical socket and more particularly pertains to an electrical socket with a flexible rotatable position for plug insertion and which is convenient for use within a small narrow space.
With the continuous developments of science and technology, electricity becomes an indispensable part of people's live and work. A variety of electrical sockets for industrial or domestic use have been developed for convenient use of electricity, thereby increasing production efficiency and living quality. However, when an electrical socket is used, if the space surrounding the socket is small and narrow, incidents of having insufficient space for plug insertion will commonly arise. This causes enormous inconvenience to people's live and work.
The inventor of the present invention disclosed a rotatable socket in a Chinese patent application (Application No.: 200420072276.2). The major construction of the socket is that a plurality of rotatable electrically conductive contact blades parallel to one another is disposed in layers inside the socket core. The rotatable electrically conductive contact blades are provided with apertures which correspond to pins of a plug for their insertion. The outer edges of the rotatable electrically conductive contact blades are connected in a sliding manner to connecting spring pieces which are fixed to the inside of the housing of the socket. The fixed connecting spring pieces can be connected to the electricity source conducting wires. When pins of a plug are inserted correspondingly into the apertures of the rotatable electrically conductive contact blades inside the socket, by rotating the plug the rotatable electrically conductive contact blades can be actuated to rotate in relation to the fixed connecting spring pieces, thereby attaining the rotation of the socket core. Although such construction attains the effect of rotating the plug, it is complicated in structure. It requires a high level of processing precision for parts. Assembling is also difficult. The pins and the apertures of the contact blades are vulnerable to wear. The life span and the safety performance of the socket are affected adversely.
BRIEF SUMMARY OF THE INVENTION
It is an object of the present invention to provide a socket with rotatable socket core which is safe and reliable and susceptible of low manufacturing costs, thereby overcoming the technical problems of the existing electrical sockets of being complicated in structure, involving high manufacturing costs, and having short life span and low safety performance.
To attain this, the present invention generally comprising
a cover having at least one opening; a base plate; an insulated electrode bracket having at least one opening which is disposed in between the cover and the base plate, wherein the inner circumferential surfaces of the openings of the electrode bracket are provided with electrically conductive members positioned separately and longitudinally, and the electrically conductive members are connected to electricity supply members which can be electrically connected to an outside electricity source; at least one socket core that is rotatable in one full circle which passes through the opening of the cover and is disposed inside the openings of the electrode bracket, wherein a plurality of apertures is disposed longitudinally inside the socket core, and a plurality of electrically conductive springs is provided inside each of the apertures, and a side portion of each of the electrically conductive springs diverges longitudinally and protrudes outwards from the outer circumferential surface of the socket core, and maintains contacts with one of the electrically conductive members correspondingly.
The electrode bracket is integrally formed or assembled into one piece or is divided into layers and stacked together to form one piece.
The electrically conductive members of the present invention can be electrically conductive rings disposed on the inner surfaces of the openings of the electrode bracket.
The socket core can comprise a core pillar with ascending steps on its outer circumferential surface, a base cover with descending steps on its outer circumference which engage with the ascending steps of the core pillar, and the protruding side portions of the electrically conductive springs are connected to where the steps of the core pillar and the base cover engage with one another respectively.
The upper surface of the cover of the present invention can be provided with a face cover having at least one opening; a mounting plate having at least one opening is disposed between the cover and the electrode bracket; and the electricity supply members are wire connecting plates which are connected to one side of the electrically conductive members.
The bottom end of the socket core of the present invention is provided with a shifting wheel; the base plate is provided with a fixation mechanism; and the fixation mechanism comprises one or more fixation members which engages with the shifting wheel and a release spring which abuts against the fixation member.
The socket core of the present invention can be molded as an integrated assembly by injection molding; and the electrically conductive springs can be molded inside the socket core directly.
The present invention can also comprise a housing enclosing the assembly formed by the cover, the base plate and the electrode bracket; the top surface of the housing has at least one opening and its bottom surface is open; the base plate and the opening surface of the housing engage and are tightly assembled together; and the electricity supply members are standard socket pins electrically connecting to the electrically conductive members and protruding from the base plate.
A ratchet wheel is disposed at the bottom end of the socket core and a ratchet pawl which engages with the ratchet wheel is disposed in the base plate.
As an alternative, the electrically conductive members can be electrically conductive contacts which are disposed on the inner circumferential surfaces of the openings of the electrode bracket.
The protruding side portions of the electrically conductive springs of the socket core can alternatively form a ring which surrounds the outer circumferential surface of the socket core and can contact the electrically conductive contacts in a sliding manner.
The apertures of the socket core of the present invention can be pillar-shaped of identical shape or combinations of different shapes.
A socket core that is rotatable in one full circle is disposed in the electrode bracket of the present invention. It maintains contacts with the electrically conductive members of the electrode bracket in a sliding manner by means of the protruded portions of the electrically conductive springs. The electrically conductive members connect through the electricity supply members to conducting wires of each phase of outside electricity source respectively. That is, when the socket core rotates 360° in relation to the fixed electrode bracket and electrically conductive members, the protruding side portions of the electrically conductive springs in the apertures remain to be electrically connected to the electrically conductive members of the electrode bracket. For the purpose of ensuring that the socket core rotates stably, the engagement of the shifting wheel at the bottom end of the socket core and the fixation mechanism can effect stable and progressive rotation of the socket core.
When a plug cannot be inserted because of insufficient space, the space limitation can be overcome by rotating and changing the angle of the socket core appropriately and the plug can then be successfully inserted into the socket. The socket core of the present invention can be used in a single socket. It can also be used in row sockets, and the insufficient space for adjacent plugs in row sockets can be overcome by rotating in the same manner. By changing the structure and shape of the electricity supply members which are connected to an outside electricity source, for example by having the electricity supply members in the shape of pins of a standard plug, the present invention possesses the additional function of a switching socket. That is, the socket of the present invention can be plugged into an existing available socket, thereby attaining the object of increasing electricity distribution. In addition, according to the number of phases of different electricity sources, such as 2-phase electricity source, 3-phase electricity source, 3-phase 4-wire electricit y source and so on, the electrode bracket can be provided with a corresponding number of electrically conductive members and the socket core can be provided with a corresponding number of apertures, thereby fulfilling different needs. The present invention is of simple construction and can be easily manufactured at low costs. Wear due to friction can also be greatly reduced, thereby increasing its life span and safety performance. It has bright promising market prospects.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention is further described in detail by means of embodiments with accompanying drawings as follows:
FIG. 1 shows the perspective view of a preferred embodiment of the present invention.
FIG. 2 shows the exploded view of the preferred embodiment of the present invention.
FIG. 3 shows the front elevational view of the preferred embodiment of the present invention with the face cover removed.
FIG. 4 shows the top plan view of FIG. 3 .
FIG. 5 shows the perspective view of the cover in FIG. 2 .
FIG. 6 shows the perspective view of the upper electrode bracket in FIG. 2 .
FIG. 7 shows the perspective view of the middle electrode bracket in FIG. 2 .
FIG. 8 shows the perspective view of the base plate in FIG. 2 .
FIG. 9 shows the perspective view of the first layer electrically conductive ring in FIG. 2 .
FIG. 10 shows the perspective view of the second layer electrically conductive ring in FIG. 2 .
FIG. 11 shows the perspective view of the third layer electrically conductive ring in FIG. 2 .
FIG. 12 shows the perspective view of the fixation mechanism in FIG. 2 .
FIG. 13 shows the perspective view of the socket core of the preferred embodiment.
FIG. 14 shows the exploded view of the socket core of the preferred embodiment.
FIG. 15 shows the cross-sectional view of the second embodiment of the present invention.
FIG. 16 shows the front elevational view of the socket core of the second embodiment.
FIG. 17 shows the top plan view of FIG. 16 .
FIG. 18 shows the exploded diagram of the third embodiment of the present invention.
FIG. 19 shows the perspective view from the top surface of the third embodiment of the present invention.
FIG. 20 shows the perspective view from the bottom surface of the third embodiment of the present invention.
FIG. 21 shows the cross-sectional view, taken along the line A—A of FIG. 20 .
FIG. 22 shows the cross-sectional view, taken along the line B—B of FIG. 20 .
FIG. 23 shows the front elevational view of the second embodiment in row sockets of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
FIGS. 1 and 2 show the basic construction of a preferred embodiment of the present invention. The socket with rotatable socket cores comprises a plastic face cover 1 with two openings. The inner surface of the face cover 1 is connected in sequence to a plastic cover 2 with two openings (as shown in FIG. 5 ), a steel mounting plate 100 with two openings (as shown in FIGS. 3 and 4 ), electrode bracket which is formed by an upper and a middle plastic electrode brackets 04 , 06 each with two openings stacked in layers to form an integrated assembly, and a base plate 08 with two hollow openings, that is, the bottom of which is sealed (as shown in FIGS. 6 to 8 ). The electrode bracket can be integrally formed or assembled into one piece or is divided into layers and stacked together to form one piece for satisfying different technical needs. The openings of the face cover 1 , the cover 2 , the mounting plate 100 , the electrode bracket 04 , 06 and the base plate 08 correspond to one another for assembling along the same axis. In this embodiment, the electrically conductive members disposed on the inner circumferential surfaces of the openings of the electrode bracket are electrically conductive rings 03 , 05 , 07 . A copper electrically conductive ring 03 is inserted into the inner circumferential surface of each opening of the upper electrode bracket 04 (forming the first layer electrically conductive ring). A copper electrically conductive ring 05 , 07 is inserted into the top end and the bottom end respectively of each opening of the middle electrode bracket 06 (forming the second layer electrically conductive ring and the third layer electrically conductive ring respectively). The electrically conductive rings of the same layer are electrically connected. On one side of the electrically conductive rings of each layer, there are copper wire connecting plates 011 , 012 , 013 which are connected to an outside electricity source (as shown in FIGS. 9 to 11 ). Two plastic socket cores 070 pass through the openings of the face cover 1 , the cover 2 and the mounting plate 100 and are inserted into the openings of the electrode bracket 04 , 06 movably, thereby enabling the socket cores 070 to rotate in one full circle in relation to the corresponding electrically conductive rings 03 , 05 , 07 (as shown in FIG. 15 ).
As illustrated in FIGS. 13 and 14 , the socket core 070 comprises a core pillar 7 A with three ascending steps 7 A 1 , 7 A 2 , 7 A 3 on its outer circumferential surface and a base cover 7 B with three descending steps 7 B 1 , 7 B 2 , 7 B 3 on its outer circumference which engage with the ascending steps of the core pillar 7 A. The core pillar 7 A and the base cover 7 B are connected together by a screw 20 to form a cylindrical pillar. The socket core 070 has three apertures 70 and each aperture 70 is provided with a copper electrically conductive spring 1 A, 10 B, 10 C. The side portions 10 A 1 , 10 B 1 , 10 C 1 of the three electrically conductive springs diverge in the upper, middle and lower directions respectively and protrude outwards from the outer circumferential surface of the socket core 070 and are connected to where the corresponding steps of the core pillar 7 A and the base cover 7 B engage with one another. As illustrated in FIG. 15 , the protruding side portions 10 A 1 , 10 B 1 , 10 C 1 of the electrically conductive springs come into contact with the inner circumferential surfaces of the corresponding electrically conductive rings 03 , 05 , 07 inside the electrode bracket 04 , 06 . That is, when the socket core 70 rotates in one full circle, the electrically conductive springs 10 A, 10 B, 10 C remain to be electrically connected to the electrically conductive rings 03 , 05 , 07 . The plastic face cover 1 can be made into different sizes and structures according to needs. The plastic face cover 1 may be removed while in use, as illustrated in FIGS. 3 and 4 .
In the second embodiment of the present invention, as illustrated in FIGS. 15 to 17 , the socket core 070 can be molded as an integrated assembly by injection molding and the electrically conductive springs 10 A, 10 B, 10 C can be molded inside the socket core 070 directly provided that the side portions 10 A 1 , 10 B 1 , 10 C 1 of the electrically conductive springs pass through and protrude outwards from the socket core 070 .
The present invention can be disposed with a plurality of the socket cores 070 according to various needs by adapting correspondingly the number of openings of the electrode bracket and the number of electrically conductive rings. As illustrated in FIG. 23 , the embodiment is row sockets disposed with six of the socket cores, thereby forming multiple sockets (serving as a junction unit).
The number of apertures 70 of the socket core 070 should be identical to the number of layers of the electrically conductive rings in the electrode bracket 04 , 06 . That is, if there are three apertures 70 in the socket core, there should be three layers of the electrically conductive rings 03 , 05 , 07 . According to use in different circumstances, the number of layers of electrically conductive rings and the number of apertures of the socket core may vary. For example, domestic sockets can be disposed with the socket cores with two apertures and two layers of electrically conductive rings (2-phase electricity source) or the socket cores with three apertures and three layers of electrically conductive rings (3-phase electricity source). As for Industrial sockets, they can be disposed with the socket cores with three apertures and three layers of electrically conductive rings or the socket cores with four apertures and four layers of electrically conductive rings (3-phase 4-wire electricity source) and so on. The shapes of the apertures 70 of the socket core 070 can be identical such as cylindrical, flat and so on, or it can be combinations of different shapes as illustrated in FIG. 4 . The electrically conductive rings 03 , 05 , 07 of the electrode bracket 04 , 06 should be in contact in a sliding manner with the protruding side portions 10 A 1 , 10 B 1 , 10 C 1 of the electrically conductive springs 10 A, 10 B, 10 C of the socket core. That is, one electrically conductive spring can only be electrically connected to electrically conductive rings of one layer but not electrically conductive rings of other layers, which is illustrated in FIGS. 15 to 17 . This construction ensures that electrically conductive rings of each layer can independently output a single phase current and guarantees safety.
As illustrated in FIG. 8 , the bottom of the base plate 08 is sealed. A groove 40 is disposed between the two openings and a fixation mechanism is disposed in the groove. As illustrated in FIG. 12 , the fixation mechanism comprises fixation members 8 A and a release spring 8 B which abuts against the fixation members. As illustrated in FIG. 13 , the bottom end of the socket core 070 is connected to a shifting wheel 13 which has teeth on its outer circumference which engage with the sharp projecting member of the fixation members 8 A. The shifting wheel can be molded as an integrated assembly with the socket core (or the base cover 7 B of the socket core) by injection molding or it can be manufactured separately and connected by a screw 20 or by adhesive. As illustrated in FIG. 15 , after assembling the sharp projecting member of the fixation members 8 A can be inserted into the notch of the shifting wheel 13 . When the socket core 070 is rotated, the fixation members 8 A move to and fro under the action of the release spring 8 B and remain to be in contact with the shifting wheel 13 all the time. By means of the engagement of the fixation mechanism and the shifting wheel 13 , the socket core 070 can exhibit two-way progressive rotation, and rotation of the socket core is maintained to be stable.
In another embodiment, the shifting wheel 13 is a ratchet wheel. The fixation mechanism is a ratchet pawl (not shown) which engages with the ratchet wheel. By means of the engagement of the ratchet wheel and the ratchet paw, the socket core 070 can also exhibit stable and progressive rotations.
As illustrated in FIG. 2 , when the socket is assembled, the two layers of electrode bracket 04 , 06 with the electrically conductive rings 03 , 05 , 07 mounted thereon are stacked together. The mounting plate 100 and the cover 2 are then installed in place. The openings of every layer align axially. The four corners are then fixed by rivets 21 . Connection can also be done by means of screws or adhesive. The socket core 070 which is pre-installed with the electrically conductive springs 10 A, 10 B, 10 C (as shown in FIG. 13 to 14 or FIG. 16 to 17 ) are then movably inserted into the openings of the electrode bracket, thereby enabling the shifting wheel 13 to engage with the fixation members 8 A which are pre-installed in the groove 40 of the base plate 08 . The face cover 1 is then placed on the top and fixed onto the other parts by a screw 19 , thereby completing the assembling of the socket. Where there is insufficient space to insert a plug, by rotating the socket core of the socket appropriately, this can effectively solve the difficulty in inserting the plug.
FIGS. 18 to 20 illustrate the basic construction of the third embodiment of the present invention. The basic construction of this embodiment is similar to that of the first embodiment of the present invention. The basic construction of this embodiment comprises three layers of insulated electrode bracket 4 , 6 , 8 with four openings, electrically conductive rings 3 , 5 , 7 which are inserted into the inner circumferential surfaces of the openings of the electrode bracket of each layer, a cover 202 on top of the upper electrode bracket 4 and socket cores 070 which are movably inserted into the openings of the electrode bracket and are rotatable in one full circle. The structure of the socket cores 070 and the relative positioning of the socket cores and the electrically conductive rings are the same as those in the first embodiment of the present invention. The difference is that this embodiment is disposed with four socket cores 070 (a plurality of socket core can be disposed according to different needs). A housing 101 is disposed, enclosing the basic construction. One end of the housing has four openings and the other end has an opening on its surface. The opening end of the housing 101 is provided with a base plate 08 with four hollow openings which encloses the basic construction. The main feature of this embodiment is that the electricity supply members are vertically connected to each layer of the electrically conductive rings 3 , 5 , 7 and protrude out from the standard socket pins 01 , 02 , 030 of the base plate 08 . That is, the electrically conductive rings of each layer connect correspondingly to one standard socket pin, as illustrated in FIGS. 21 and 22 . The shapes of the socket pins can be identical such as cylindrical, flat and so on, or it can be combinations of different shapes as illustrated in FIG. 20 , so that socket pins of different technical standards can be made. The electrically conductive rings are connected to an outside electricity source by means of the socket pins. Apart from having the function of the rotatable socket cores, this embodiment possesses an additional function of switching sockets. When a number of plugs are to be inserted, this can be done by simply plugging the socket pins of this embodiment into an existing available single socket.
In the third embodiment, a ratchet wheel 13 is disposed at the bottom of the socket core 070 and a ratchet pawl (not shown) which engages with the ratchet wheel 13 is disposed in the centre of the inner surface of the base plate 08 . After assembling, the sharp projecting member of the ratchet pawl inserts into the notch of the ratchet wheel 13 . When the socket core 070 rotates, the socket core 070 can exhibit stable and progressive rotation by means of the engagement of the ratchet pawl and the ratchet wheel 13 .
As illustrated in FIG. 18 , when the socket of the third embodiment is assembled, the electrode bracket 4 , 6 , 8 which are pre-mounted with the electrically conductive rings 3 , 5 , 7 , are stacked together. The cover 202 is then placed on top of the upper electrode bracket and fixed by rivets at its four corners. Connection can also be done by means of screws or adhesive. The socket core 070 which is pre-installed with the electrically conductive springs 10 A, 10 B, 10 C are then movably inserted into the openings of the electrode bracket, thereby completing the assembling of the basic construction. The housing 1 and the base plate 08 are then installed, so that the standard socket pins 01 , 02 , 030 which are connected to the electrical conductive rings 3 , 5 , 7 pass through and protrude out from the base plate 08 and that the ratchet wheel 13 engages with the ratchet pawl (not shown) which is pre-mounted on the inner surface of the base plate 08 . The parts are fixed together (as illustrated in FIGS. 21 to 22 ) by a screw 23 , thereby completing the assembling of the socket. When a number of plugs are to be inserted, the present invention can be plugged into an existing socket. Where there is insufficient space to insert a plug, by rotating the socket core of the socket appropriately, this can effectively solve the difficulty in inserting the plug.
In other embodiments of the present invention, the electrically conductive members 03 , 05 , 07 which are disposed on the inner circumferential surfaces of the openings of the insulated electrode bracket can be configured into a contact structure. The protruding side portions 10 A 1 , 10 B 1 , 10 C 1 of the electrically conductive springs of the socket core corresponding to the contacts can be configured into a ring structure along the outer circumferential surface of the socket core. When the socket core 070 rotates in one full circle, the electrically conductive members and the electrically conductive springs remain to be in electrical contact with one another (not shown).
Apart from the constructions of the above embodiments, the construction of the electrically conductive members disposed on the inner circumferential surfaces of the openings of the insulated electrode bracket and the construction of the electrically conductive springs which engage with the corresponding electrically conductive members in a complete circle can be in various forms. Any of those forms in which the electrically conductive springs of the socket core remain to be in electrical contact with the conductive members When the socket core rotates in one full circle fall within the scope of the claims of the present invention. | The present invention relates to an electrical socket with rotatable socket core. It comprises a cover having at least one opening; a base plate; an electrode bracket having at least one opening which is disposed in between the cover and the base plate; and at least one socket core that is rotatable in one full circle which passes through the opening of the cover and is disposed inside the openings of the electrode bracket, wherein a plurality of apertures is disposed longitudinally inside the socket core. While inserting, if there is insufficient space, the space limitation can be overcome by rotating and changing the angle of the socket core appropriately and the plug can be successfully inserted into the socket. | 7 |
FIELD OF THE INVENTION
The invention described herein relates to novel copolymers comprising polymer units derived from perfluoroalkylethyl (meth)acrylates, vinylidene chloride, and alkyl(meth)acrylates which, in the form of aqueous compositions, will impart oil-, alcohol- and water-repellency to fabrics without the need to utilize heat-curing of the treated substrate as practiced in the prior art. (In all instances herein, the term "(meth)acrylate" is used to denote either acrylate or methacrylate, and the term "N-methylol(meth)acrylamide" is used to denote either N-methylolacrylamide or N-methylolmethacrylamide.
BACKGROUND OF THE INVENTION
Perfluoroalkylethyl (meth)acrylate-containing copolymers having utility as textile-treating agents for the purpose of imparting oil- and water-repellency are known. Solvent-based formulations which do not require a heatcuring step during application have been described by Kirimoto and Hayashi in U.S. Pat. No. 3,920,614; however, environmental and safety concerns now require virtually all such applications to be made from aqueous formulations in place of organic solvents. Greenwood, Lore, and Rao, in U.S. Pat. No. 4,742,140, disclose perfluoroalkylethyl acrylate/vinylidene chloride/alkyl (meth)acrylate copolymers which, after application to polyamide textile substrates from an aqueous formulation, imparted oil- and water-repellency to the substrates. The Greenwood et al. perfluoroalkylethyl acrylate monomers have the formula:
CF.sub.3 --CF.sub.2 --(CF.sub.2).sub.k --C.sub.2 H.sub.4 --OC(O)CH═CH.sub.2
in which the monomer molecular weight distribution is given as:
0-10 weight % of the fluoromonomer with k=or >4
45-75 weight % of the fluoromonomer with k=6
20-40 weight % of the fluoromonomer with k=8
1-20 weight % of the fluoromonomer with k=10
0-5 weight % of the fluoromonomer with k=or >12
All of the prior compositions which can be applied from an aqueous emulsion require a heat-curing step after application and drying. For example, Greenwood et al. heat-treated the fabric at 140° C. to 190° C. for at least 30 sec, typically 60 to 180 sec.
SUMMARY OF THE INVENTION
The present invention relates to novel aqueous emulsion polymers based on lower homologue distributions of perfluoroalkylethyl (meth)acrylates copolymerized with vinylidene chloride and nonfluorinated alkyl (meth)acrylates; optionally with N-methylol(meth)acrylamide, hydroxyalkyl (meth)acrylates, and/or alkyloxy (meth)acrylates. It relates also to the use of the copolymers as oil-, water- and alcohol-repellents. The copolymers impart high levels of water-, alcohol- and oil-repellency to fabrics under milder drying and curing conditions than those required to achieve commercially useful repellent properties with conventional aqueous fabric treatment compositions. The aqueous dispersions can be used to treat a variety of woven and nonwoven textile fabrics made from natural or synthetic fibers including cotton, cellulose, wool, silk, polyamide, polyester, polyolefin, polyacrylonitrile, rayon, acetate as well as paper and leather substrates.
DETAILED DESCRIPTION OF THE INVENTION
The perfluoroalkylethyl (meth)acrylates useful for preparing the novel copolymers of this invention are in the form of mixtures of monomers having the formula:
CF.sub.3 CF.sub.2 (CF.sub.2).sub.k CH.sub.2 CH.sub.2 OC(O)C(R )═CH.sub.2
wherein R═H or CH3, and k is 4,6,8,10 and 12 consisting essentially of:
25-70 weight % of monomers wherein k=4 or less
20-40 weight % of monomers wherein k=6
5-25 weight % of monomers wherein k=8
0-15 weight % of monomers wherein k=10 or greater.
In a particular embodiment (hereinafter "low distribution"), the distribution is essentially as follows:
45-70 weight % of monomers wherein k=4 or less
20-35 weight % of monomers wherein k=6
5-10 weight % of monomers wherein k=8
0-5 weight % of monomers wherein k=10 or greater;
In another particular embodiment (hereinafter "middle distribution"), the distribution consists essentially of:
25-45 weight % of monomers wherein k=4 or less
25-40 weight % of monomers wherein k=6
10-25 weight % of monomers wherein k=8
1-15 weight % of monomers wherein k=10 or greater.
Because of their industrial availability, fluoropolymers of this invention which are based on the "middle distribution" are considered to be the best mode of carrying out the invention, particularly the fluoropolymer of EXAMPLE 6.
The nonfluorinated (meth)acrylates comprise alkyl (meth)acrylates in which the alkyl group is a straight or branched chain radical containing 2 to 20 carbon atoms, preferably 8 to 18 carbon atoms. The C 2 -C 20 alkyl (meth)acrylates (linear or branched) are exemplified by, but not limited to, alkyl(meth)acrylates where the alkyl group is ethyl, propyl, butyl, isoamyl, hexyl, cyclohexyl, octyl, 2-ethylhexyl, decyl, isodecyl, lauryl, cetyl, or stearyl. The preferred examples are 2-ethylhexyl acrylate, lauryl acrylate and stearyl acrylate. Optional N-methylol monomers are exemplified by, but not limited to N-methylolacrylamide and N-methylolmethacrylamide. The optional hydroxyalkyl (meth)acrylates have alkyl chain lengths in range between 2 and 4 carbon atoms, and are exemplified by 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate. The optional alkyloxy(meth)acrylates also have alkyl chain lengths in range between 2 and 4 carbon atoms, and contain between 1 and 12 oxyalkylene units per molecule, preferably between 4 and 10 oxyalkylene units per molecule, and most preferably between 6 and 8 oxyalkylene units per molecule, as determined by gas chromatography/mass spectrometry. Specific examples of the poly(oxyalkylene)(meth)acrylates are exemplified by, but not limited to, the reaction product of 2-hydroxyethyl methacrylate and nine mols of ethylene oxide (also known as 2-hydroxyethyl methacrylate/9-ethylene oxide adduct) and the reaction product of 2-hydroxyethyl methacrylate and six mols of ethylene oxide (also known as 2hydroxyethyl methacrylate/6-ethylene oxide adduct). In an embodiment, the copolymers are made from 50-80 wt. % perfluoroalkylethyl (meth)acrylates, 10-40 wt. % C 2 -C 20 alkyl (meth)acrylates, 10-40 wt. % vinylidene chloride, 0-2 wt. % N-methylol-acrylamide, 0-2 wt. % 2-hydroxyethyl methacrylate and 0-5 wt. % poly(oxyethylene)methacrylate.
The fluorinated copolymers of this invention are prepared in water by free radical initiated emulsion polymerization of a mixture of perfluoroalkylethyl (meth)acrylate homologues with vinylidene chloride, alkyl (meth)acrylates, and, optionally, N-methylol(meth)acrylamide and hydroxyalkyl- or alkyloxy(meth)acrylates. The fluoropolymers of this invention are made by agitating the monomers described above in water with a surfactant in a suitable reaction vessel which is equipped with an agitation device and an external heating and cooling device. A free radical initiator is added and the temperature raised to 40°-70° C. A polymerization regulator or chain transfer agent may be added to control molecular weight of the resultant polymer. The product of the reaction is an aqueous dispersion which is diluted further with water. The polymerization initiator is exemplified by, but not limited to, 2,2'-azobis(2-amidinopropane dihydrochloride or 2,2'-azobis(isobutyramidine) dihydrochloride. The polymerization regulator or chain transfer agent is exemplified by, but not limited to, dodecylmercaptan.
The fluoropolymers of this invention will impart oil- and water-repellency to fibrous substrates, such as textile fabrics, without heating the treated substrate above room temperature (about 20° C.). Thus, the fluoropolymers can be applied to the subtrate in the form of an aqueous emulsion by conventional techniques, such as padding or spraying, after which excess liquid is squeezed off or removed by vacuum. After removal of excess liquid, development of the water- and oil-repellency characteristics of the substrate can be achieved simply by air-drying the treated substrates. The period of time required to effect air-drying will be apparent to one skilled in the art by observation. As would be expected, the time needed to complete air-drying of the treated substrate will vary, depending on a number of factors, such as the composition and weight of the substrate, the quantity of liquid retained by the substrate at the time air-drying is commenced, and the like. While heating is not necessary for development of the repellent properties of the polymers of this invention, the treated fabric may be warmed for a matter of seconds so as to speed up the completion of air-drying. In one embodiment, the treated fabric was air-dried for about 16 to 24 hours at about 20° C.; in another, about 72 hours at about the same temperature. In yet another embodiment, the treated fabric was air-dried for about 16 to 24 hours at about 20° C., and thereafter heated at about 38° C. for about 10 seconds.
In the Examples that follow, further illustrating the invention, the terms "perfluoroalkylethyl acrylate mixture A" and "perfluoroalkylethyl acrylate mixture B" refer respectively to mixtures of perfluoroalkylethyl acrylates having the "low distribution" and the "middle distribution" described above.
EXAMPLE 1
A water emulsion was prepared by mixing the following:
64.0 g of perfluoroalkylethyl acrylate mixture A
18.0 g stearyl methacrylate
8.0 g stearic acid/14-ethylene oxide adduct
2.0 g 2-hydroxyethyl methacrylate/9-ethylene oxide adduct
1.0 g N-methylolacrylamide
1.0 g 2-hydroxyethyl methacrylate
0.5 g dodecylmercaptan
140.0 g deionized water.
The emulsion was added to a glass reaction vessel equipped with an agitator, a thermometer and a dry-ice condenser. The mixture was purged with nitrogen gas for one hour, and then the nitrogen purge was switched to a positive pressure nitrogen blanket. To the aqueous monomer emulsion were added 18.0 g of vinylidene chloride, 50.0 g acetone and 1.0 g 2,2'-azobis(2-amidinopropane dihydrochloride dissolved in 10 g deionized water to initiate the polymerization. The resultant mixture was heated to 50° C. and held at 50° C. for 8 hours. The polymerization yielded a polymer latex weighing 321 g with a solids content of 34.8%.
EXAMPLE 2
A water emulsion was prepared by mixing the following:
30.0 g of perfluoroalkylethyl acrylate mixture A
10.0 g of stearyl acrylate
4.0 g of stearic acid/14-ethylene oxide adduct
1.0 g of 2-hydroxyethyl methacrylate/9-ethylene oxide adduct
0.15 g of ethoxylated carboxylated octadecylamine
0.5 g of N-methylolacrylamide
0.5 g of 2-hydroxyethyl methacrylate
0.25 g of dodecylmercaptan
10.0 g hexylene glycol
100.0 g deionized water.
The emulsion was added to a glass reaction vessel equipped with an agitator, a thermometer and a dry ice condenser. The mixture was purged with nitrogen gas for one hour, and then the nitrogen purge was switched to a positive pressure nitrogen blanket. To the aqueous monomer emulsion were added 10.0 g of vinylidene chloride and 0.5 g 2,2'-azobis(2-amidinopropane dihydrochloride dissolved in 5.0 g deionized water to initiate the polymerization. The resultant mixture was heated to 50° C. and held at 50° C. for 8 hours. The polymerization yielded a polymer latex weighing 175 g with a solids content of 31.1%.
EXAMPLES 3-10 & CONTROLS A & B
Emulsion polymers were prepared substantially according to the procedure of Example 2 to provide the compositions given in Table 1.
TABLE 1__________________________________________________________________________ Quantity of Monomers in Emulsion for Example/Control (parts by weight)Monomer 3 4 5 6 7 8 9 10 A B__________________________________________________________________________Perfluoroalkylethyl 60 0 0 0 0 0 0 0 0 0acrylate BPerfluroalkylethyl 0 60 0 0 0 0 0 0 0 0methacrylate APerfluoroalkylethyl 0 0 60 60 80 50 60 60 60 60methacrylate B2-Ethylhexyl 20 0 20 0 0 0 0 0 0 0methacrylate2-Ethylhexyl Acrylate 0 0 0 20 10 10 0 0 0 0Stearyl methacrylate 0 20 0 0 0 0 0 0 0 0Stearyl acrylate 0 0 0 0 0 0 0 20 40 0Lauryl acrylate 0 0 0 0 0 0 20 0 0 0Vinylidene chloride 20 20 20 20 10 40 20 20 0 20N-methylolacrylamide 1 1 1 1 1 1 1 1 1 12-Hydroxyethyl 1 1 1 1 1 1 1 1 1 1methacrylate2-Hydroxyethyl methacrylate/ 2 2 2 0 0 0 2 2 2 010-Ethylene oxide adduct2-Hydroxyethyl methacrylate/ 0 0 0 2 2 2 0 0 0 27-Ethylene oxide adduct__________________________________________________________________________
TEST METHODS
the following test methods were used to evaluate substrates treated with the fluoropolymers of EXAMPLES 1-10, CONTROLS A, B and other CONTROLS:
REPELLENCY TESTING
1. Fabric Treatment
A portion of the polymer dispersion was diluted with water to a polymer content of 0.5-2%, such that, after application to selected. fabrics by padding, a fluorine level of 900-1200 ppm based on weight of fabric was obtained. The fabrics selected for testing included a blue nylon taffeta, a polyolefin nonwoven and undyed nylon and cotton upholstery fabrics. The polyolefin fabric was dried at room temperature for 24 hours and then heat-treated at 38° C. for 10 seconds. The nylon taffeta fabric was air-dried for 24 hours and the upholstery fabrics were air-dried for 72 hours.
2. Water Repellency Spray Test
The treated fabric samples were tested for alcohol repellency using AATCC Standard Test Method No. 22 of the American Association of Textile Chemists and Colorists. In that test, 250 mL of water were poured in a narrow stream at a 27 degree angle onto a fabric sample stretched on a 6-inch (15.2 cm) diameter plastic hoop. The water was discharged from a funnel suspended six inches (15.2 cm) above the fabric sample. After removal of excess water, the fabric was visually scored by reference to published standards. A rating of 100 denotes no water penetration or surface adhesion; a rating of 90 denotes slight random sticking or wetting; lower values indicate greater wetting and a rating of 0 indicates complete wetting.
3. Water Repellency Test
A series of standard test solutions made from water and isopropyl alcohol (IPA) identified in Table 2 were applied dropwise to the fabric samples. Beginning with the lowest numbered test liquid (Repellency Rating No. 1 ) one drop (approximately 5mm in diameter or 0.05 mL volume) was placed on each of three locations at least 2 inches apart. The drops were observed for ten seconds. If after ten seconds two of the three drops were still visible as spherical to hemispherical, three drops of the next higher numbered test liquid were placed on adjacent sites and observed for ten seconds. This procedure was continued until one of the test liquids results in two of the three drops failing to remain spherical to hemispherical. The water repellency of the fabric was the highest numbered test liquid for which two of the three drops remained spherical to hemispherical.
TABLE 2__________________________________________________________________________STANDARD WATER TEST SOLUTIONSWater Repellency Composition Water Repellency CompositionRating Number % IPA % Water Rating Number % IPA % Water__________________________________________________________________________1 2 98 7 50 502 5 95 8 60 403 10 90 9 70 304 20 80 10 80 205 30 70 11 90 106 40 60 12 100 0__________________________________________________________________________
4. Oil Repellency
Treated fabric samples were tested for oil repellency by a modification of AATCC Standard Test Method No. 118, conducted as follows. A series of organic liquids, identified below in Table 3 were applied dropwise to the fabric samples. Beginning with the lowest numbered test liquid, (Repellency Rating No. 1) one drop (approximately 5 mm in diameter or 0.05 mL volume) was placed on each of three locations at least 5 mm apart. The drops were observed for 30 seconds. If, at the end of this period, two of the three drops were still spherical to hemispherical in shape with no wicking around the drops, three drops of the next highest numbered liquid were placed on adjacent sites and similarly observed for 30 seconds. The procedure was continued until one of the test liquids results in two of the three drops failing to remain spherical to hemispherical, or wetting or wicking occurs. The oil-repellency rating of the fabric is the highest numbered test liquid for which two of the three drops remain spherical to hemispherical, with no wicking for 30 seconds.
TABLE 3______________________________________OIL REPELLENCY TEST LIQUIDSOil RepellencyRating Number Test Solution______________________________________1 Nujol* Purified Mineral Oil (*Trademark of Plough, Inc.)2 65/35 Nujol/n-hexadecane by volume3 n-hexadecane4 n-tetradecan4 n-dodecane6 n-decane______________________________________
Using the foregoing three TEST METHODS to treat fabrics with the fluoropolymer compositions of EXAMPLES 1-10 and CONTROLS A, B, C & D (described below), all in the form of aqueous emulsions, showed that the fluoropolymers of EXAMPLES 1-10 imparted oil- and water-repellency to the fabrics tested without the need to effect curing at elevated temperature by prior art procedures, whereas the CONTROL polymers either failed to do so at all or did so to an extent which would not be suitable commercially. CONTROL A contained no polymer units derived from vinylidene chloride. CONTROL B contained no polymer units derived from a nonfluorinated (meth)acrylate. CONTROL C consists of an aqueous emulsion copolymer of 60% perfiuoroalkylethyl acrylate, 20% stearyl acrylate, 20% vinylidene chloride, 1% each N-methylolacrylamide, 2-hydroxyethyl methacrylate and 2% 2-hydroxyethyl methacrylate/ethylene oxide (6) adduct. The perfiuoroalkylethyl acrylate used to produce the CONTROL C finish was a mixture of monomers characterized by the general formula:
CF.sub.3 CF.sub.2 (CF.sub.2).sub.k C.sub.2 H.sub.4 OC(O)CH═CH.sub.2
wherein k=4, 6, 8, 10, and ¢12 as described by Greenwood, et al. (vide supra). CONTROL D is a commercial repellent product for textiles derived from a physical blend described in U.S. Pat. No. 4,595,5 18 which is based on:
1. A Perfiuoroalkylethyl citrate urethane (anionic dispersion);
2. A 75/25/0.25/0.25 perfiuoroalkylethyl methacrylate/2-ethylhexylmethacrylate/N-methylol-acrylamide /2-hydroxyethyl methacrylate copolymer;
3. A 65/35/0.25 perfiuoroalkylethyl methacrylate/Lauryl methacrylate/N-methylolacrylamide copolymer and
4. Neoprene Latex, dispersed with Tween 80 surfactant, and the pH adjusted with polydimethylaminoethylmethacrylate/acrylics. | Lower homologue perfluoroalkylethyl (meth)acrylates copolymerized with vinylidene chloride and alkyl (meth)acrylates; optionally with N-methylolacrylamide, hydroxyalkyl (meth)acrylates, and/or alkyloxy (meth)acrylates, impart high levels of water-, alcohol- and oil-repellency to fabrics under mild conditions. | 3 |
FIELD OF THE INVENTION
This invention relates to a rock bolting system. The invention is also concerned with a method of rock bolting.
DESCRIPTION OF THE BACKGROUND ART
There is a large number of rock bolt devices commercially available for installation within boreholes drilled into rock. These have a variety of general and special uses as rock reinforcement in both civil and mining engineering. One particular class of these devices is known as "Friction Rock Stablisers". These devices are usually compressed or expanded to fit the borehole and consequently achieve their reinforcing ability by virtue of friction (and to some extent mechanical interlock) at the interface between their outer surface and the borehole wall. These devices include the "Swellex", the "Split Set", the "Pipe Bolt" and the "Rock Nail".
"Swellex" bolts were introduced into Australia in approximately 1984. The bolt is described in Australian Patent Application no. 545968 and essentially comprises an elongated tube which has an axial depression and an internal pressure fluid receiving chamber which is closed at both ends but has a fluid inlet at one end thereof. The bolt may also comprise a fixed sleeve on one end of the tube which is the outer end of the tube, the sleeve and tube having a hole there through to communicate with the internal chamber of the tube so that the hole forms the fluid inlet. When the device is installed in an oversize bore hole and fluid is injected through the inlet the inflation pressure causes both the steel tube and to a lesser extent, the rock to expand. When the pressure is released, the rock relaxes and an interface pressure is established between the steel tube and the rock surface. Resistance to pull-out is caused by friction and mechanical interlock between the steel tube and the rough borehole wall.
A consistent and quality assured installation is the primary requirement for all rock reinforcement systems. This prerequisite is assured for the "Swellex" bolt by an elegant insertion and inflation procedure. Furthermore, this simple procedure does not require high operator expertise. However, the mechanical properties of the installed "Swellex" can be improved to address the fundamental modes of action required of rock reinforcing systems. That is, modification to the axial and shear strengths and stiffnesses.
Another form of stabilising device is the "Split Set" bolt. The "Split Set" bolt has been used in Australia since the 1970's. The Split Set bolt comprises a split tube formed from a hot-rolled steel sheet of a certain thickness which is formed in a tube rolling mill. Instead of closing the tube a longitudinal slot is left open. The split tube is cut to length, one end is tapered and a formed ring is welded to the opposite end. The tapered end allows forced insertion into an undersized borehole. The ring is intended to support a face plate at the borehole collar. In use, the "Split Set" bolt is driven into the bore hole, compressing the split tube and causing an interfacial pressure between the bolt and the rock. Resistance to pull out is due mainly to friction.
The ideal rock reinforcement device is one in which the design capacity is achieved at an appropriate stiffness without rupture of the element, irrespective of displacement. To achieve this, slip must occur between one or more of the constituent interfaces between the device and the host rock. That is, an ideal bolt may be loaded to a design load prior to slip and that a substantial proportion of this load is maintained during subsequent slippage.
The "Split Set" bolt described above goes some way towards this ideal. Slippage can occur for large displacements without rupture occurring. However, its frictional anchoring capacity is usually significantly less than its axial strength. To increase anchoring capacity a smaller bore hole may be used. However, this makes installation difficult if not impossible.
The "Swellex" bolt has the potential to achieve the stated aims of an ideal device. This could be achieved by reducing the installation pressure. However, reduction of installation pressure results in unpredictable performance. Thus, the great advantage of a consistent high quality installation is lost.
DISCLOSURE OF THE INVENTION
The prime objective of the present invention is to provide a rock bolt system and a method for installing rock bolts which overcome, or at least mitigate, some of the problems with the previously described rock bolts.
Accordingly, in one aspect, there is provided a rock bolt system comprising an inner part disposed within an outer part, said inner part comprising a fluid expansible elongated tube having an internal closed ended fluid receiving chamber having a fluid inlet, said outer part comprising an elongated tube having a longitudinal slot, said slot extending at least part way along the length of said tube of said outer part.
In a second aspect, the present invention provides a rock bolt system comprising an inner part disposed within outer part, said inner part comprising an elongated tube having an axial depression and an internal pressure fluid receiving chamber which is closed at both of its ends and having a fluid inlet communicating with said fluid receiving chamber, said outer part comprising an elongated tube having a longitudinal slot, said slot extending at least part way along the length of said tube of said outer part.
In a further aspect, the present invention provides a method for rock bolting said method comprising providing a rock bolt system within a borehole, said rock bolt system comprising an inner part disposed within an outer part, said inner part comprising a fluid expansible elongated tube having an internal closed ended fluid receiving chamber having a fluid inlet, said outer part comprising an elongated tube having a longitudinal slot, said slot extending at least part way along the length of said tube of said outer part, supplying fluid under pressure to said fluid receiving chamber through said fluid inlet to expand said expansible tube and expand said slotted tube in said borehole.
The inner part may be an Atlas Copco standard "Swellex" bolt.
Preferably, although not necessarily, after expansion the aperture in the outer tube is diametrically opposite to the depression in the inner tube.
This invention relates to a new and additional device which, at first glance would appear to comprise simply coupling the "Swellex" with the "Split Set". Although these two devices are particularly relevant to this invention the fundamental mechanics of installation and operation of the present invention are markedly different from that of either individual or coupled use of the "Swellex" and the "Split Set".
The rock bolt system of the present invention has four principal attributes. Two are concerned with its installation into boreholes and two are concerned with its operation as a reinforcement system. In terms of installation the invention maintains the advantages of the original "Swellex":
ease of insertion in the borehole, combined with
quality assured installation.
In terms of operation it provides:
flexibility of design configuration, together with
optimum use of material properties as reinforcement.
The aim of the present invention is to provide a reinforcement assembly which may be arranged to supply the required axial and shear capacities and stiffnesses to suit different modes of operation demanded of reinforcement systems. For example this may be achieved by varying:
the outer tube geometry (i.e. profile, length, diameter, thickness, slot length)
the outer tube properties (i.e. material type, constitutive behaviour, coefficient of friction)
the inflation agent and procedure (pressure, fluid type and method)
the interface between the inner and outer components (lubricated or rough interface may be arranged). Similarly the longevity and corrosivity and suitability to different environments may be arranged by judicious choice of insertion fluid agents and constituent component material types and coatings.
The invention is preferably used in the same nominal sizes as the "Swellex" and the "Split Set" bolts and is also compatible with current drilling and installation machinery. This is currently limited to devices to suit approximately 38 mm to 40 mm and approximately 44 mm to 46 mm diameter boreholes and in lengths ranging from approximately 1 m to 4 m. Clearly, the rock bolt system of the invention is not limited by size and is equally applicable in larger or smaller diameters and lengths.
In order that the invention may be more fully understood we provide the following non-limiting examples.
Further scope of applicability of the present invention will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will become more fully understood from the detailed description given hereinbelow and the accompanying drawings which are given by way of illustration only, and thus are not limitative of the present invention, and wherein:
FIG. 1 shows a cross-sectional view of a rock bolt system in accordance to the invention prior to expansion;
FIG. 2 shows a cross-sectional view of a rock bolt system in accordance with the invention after expansion;
FIG. 3 is a graph showing axial test results; and
FIG. 4 is a graph showing shear test results.
The most basic form of the invention is shown in FIG. 1. The rock bolt system comprises an inner tube 1 (which may be a "Swellex" bolt P.A. No. 545968).
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The invention will now be described in reference to the use of a "Swellex" bolt as the inner tube 1, however the invention is not to be seen as limited to the use of this bolt.
The "Swellex" bolt 1 is located within a second outer tube 10 which has a longitudinal slot 12. It will be seen from the drawing that the axial depression 2 of the "Swellex" bolt is located diametrically opposite the aperture 12 of the outer tube. The first tube ("Swellex" bolt)--second tube combination is located within borehole 20 of rock 25. The outer tube may be tapered at one end to facilitate insertion into the borehole. Expansion is achieved by supplying high pressure liquid to the inner "Swellex" bolt. In the process of expansion the inner "Swellex" bolt eventually comes into contact with the outer split tube effecting expansion of the outer split tube against the walls of the borehole.
FIG. 2 shows the bolting system of the invention after expansion of the inner "Swellex" bolt 30.
Whilst the outer tube adds to the apparent stiffness of the bolt, it should be noted that the axial stiffness is also affected by the rate of load transfer from the rock to the outer tube and from this tube to the inner "Swellex" bolt.
A laboratory testing program has been undertaken to quantify some of the differences in response between the standard "Swellex" bolt and two variants of the bolt according to the invention.
Reinforcing devices are designed to reinforce discontinuties such as pre-existing joints or propagating cracks. They attempt to control the opening and shearing displacements that can occur at these discontinuities. The laboratory tests were designed to simulate these two aspects of reinforcement loading, discontinuity opening or tensile loading and discontinuity shearing or shear loading.
The standard "Swellex" bolt manufactured to suit 38 mm to 40 mm diameter boreholes was chosen for testing. Preferred bolt variants according to the invention comprise an inner standard "Swellex" bolt with an outer split tube sleeve. In the first variant of the invention, the outer sleeve comprised a 31.8 mm diameter, 1.6 mm wall thickness steel tube. In the second variant, the outer sleeve comprised a 35.0 mm diameter, 3.2 mm wall thickness steel tube.
TESTING ARRANGEMENTS
In all cases the specimens were installed within 40 mm internal diameter, 17.5 mm thick walled steel containment tubes. These very thick and rigid containment tubes were designed to duplicate the radial confinement supplied by an average rock. The containment tubes are made up of two tube lengths butted together. The reinforcement device is inserted into the tube to span this butt joint and then inflated. Once inflated the butt joint is used to simulate a discontinuity by forcing the specimen to extend or shear at this interface. This arrangement of the specimen containment tubes was compatible with both the axial and the shear testing facilities.
Discontinuity opening or tensile loading was simulated by securing the two containment tubes and pulling them apart, thereby inducing tension in the reinforcing device at the test interface. The containment tubes were secured by a universal testing machine approximately 500 mm either side of the test interface. The variables measured included the load supplied by the machine and the axial displacement at the test interface.
Discontinuity shearing or shear loading was simulated by placing the test specimen in a shear facility. The facility is placed within a universal test machine which supplies a shearing force at the test interface. The transverse movement of one containment tube relative to the other side of the test interface causes shearing of the specimens. The variables measured included the shear load supplied by the machine and the shear displacement at the test interface.
RESULTS AND COMPARISON
A set of axial tension test was performed to determine whether the behavior of standard "Swellex" bolts installed in thick walled steel containment tubes was representative of their behavior in rock. The embedment length on one side of the test interface was held constant at relatively long length (1.5 m) and the embedment length on the other side of the test interface was varied. This arrangement allowed slippage from the short embedment length to be studied. The results summarised in Table 1 are in agreement with the performance expected of standard "Swellex" bolts installed in hard rock. The strength increases as the embedment length increases and failure is by slippage of the "Swellex" bolts installed in hard rock. The strength increases as the embedment length increases and failure is by slippage of the "Swellex" from within the containment tube. Although failure at the longer embedment lengths was by slippage, the yield strength of the "Swellex" bolt material was exceeded.
TABLE 1______________________________________Summary of Laboratory Tension TestsLong Short PeakEmbedment (m) Embedment (m) Load (kN)______________________________________1.5 0.50 801.5 0.75 1001.5 1.00 1101.5 1.25 120______________________________________
A series of tests was designed to compare the performance of rock bolts according to the invention with the standard "Swellex" in both axial tension and shear. The results for axial tension tests are summarised in FIG. 3 and the results obtained in the shear tests are summarised in FIG. 4.
These results demonstrate that:
axial load transfer decreases as the split tube thickness increases
shear strength increases as the outer split tube thickness increases.
These results show that the bolt of the invention can be arranged to achieve a range of axial load transfer and shear strengths. This ability is consistent with the requirements of a variety of reinforcement applications for excavations in jointed rock. This range of mechanical properties can be achieved whilst maintaining a consistent and quality assured reinforcement installation.
In practice, reinforcement devices are subject to combined axial and shear loading caused by opening and shear of the discontinuities which they reinforce. It is therefore particularly important that bolts of the invention have a high shear strength combined with adequate resistance to axial loading.
The preliminary tests have used a standard "Swellex" bolt for inflation and outer split tubes made from steel. This has dictated the range of sizes used for the bolts. It will be appreciated however that the size of the bolt will not be limited to these sizes and the outer tube may be made from a range of materials consistent with the requirements of the application.
The invention being thus described, it will be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the invention, and all such modifications as would be obvious to one skilled in the art intended to be included within the scope of the following claims. | A rock bolt system comprises an inner part (1) disposed within an outer part (10). The inner part comprises an elongated tube having an axial depression (2) and an internal pressure fluid receiving chamber (4) which is closed at both of its ends. A fluid inlet communicates with the fluid receiving chamber. The outer part (10) comprises an elongated tube having a longitudinal slot (12), which slot extends at least part way along the length of the outer part tube. In use, the rock bolt system is placed in an oversized borehole (20) and pressurized fluid applied to the fluid receiving chamber. This causes the device to expand laterally and engage the walls of the borehole. | 4 |
CROSS REFERENCE TO RELATED APPLICATION
[0001] This application claims the benefit of provisional patent application Ser. No. 62/008,544, filed on Jun. 6, 2014, the entire contents of which are incorporated herein by reference,
FIELD
[0002] The present invention relates generally to beacons and antennas for use with downhole tools drilling operations.
SUMMARY
[0003] The present invention is directed to a downhole tool coupled to a drill string comprising a sensor, an antenna electromagnetically coupled to the sensor, and a wall disposed between the antenna and the sensor. The wall comprises a connection point for connection to the drill string,
[0004] In another embodiment, the present invention is directed to a beacon assembly for attachment to a downhole end of a drill string. The drill string comprises a substantially constant first diameter. The beacon assembly comprises a housing wall, an antenna, and a sensor. The housing wall comprises a first portion and a second portion. The first portion has substantially the first diameter. The second portion has a second diameter which is less than the first diameter. The antenna is located about the second portion of the housing wall. The sensor is located within the housing wall electronic communication with the antenna.
BRIEF DESCRIPTION OF THE DRAWINGS
[0005] FIG. 1 is a cross-sectional side view of a downhole tool having an external antenna.
[0006] FIG. 2 is a perspective view of a beacon assembly of the downhole tool of FIG. 1
[0007] FIG. 3 is a perspective sectional view of the antenna assembly of the downhole tool of FIG. 1 .
[0008] FIG. 4 is a partial sectional end view of the downhole tool, showing the antenna assembly of the downhole tool.
[0009] FIG. 5 is a cross-sectional side view of an alternative embodiment of the antenna assembly of the downhole tool with the antenna coil shown un-sectioned for clarity.
DESCRIPTION
[0010] Horizontal Directional Drilling (HDD) applications typically employ a subsurface tracking beacon and a walk-over tracking receiver to follow the progress of a horizontal borehole. An example of a walkover receiver and method for use thereof is shown in U.S. Pat. No. 8,497,684 issued to Cole, et, al., the contents of which are incorporated herein by reference. The tracking beacon contains devices to measure pitch, roll (bit angle), beacon battery voltage, beacon temperature, and a variety of other physical parameters. Measured information is transmitted by the beacon using a modulated electromagnetic signal. Transmission of the beacon's signal typically involves an internal antenna consisting of multiple wire turns wrapped around a ferrite rod. The surface tracking receiver contains electronic elements which receive and decode the modulated signal. The surface tracking receiver also detects the signal's field characteristics and measures the beacon's emitted signal amplitude to estimate the beacon's depth and location.
[0011] In some cases, the beacon measurements of interest are magnetic field measurements. Certain applications require the use of magnetic field gradiometers, which are instruments used to determine a magnetic field's rate of change along a certain path. Magnetic field gradiometers essentially involve magnetic field measurements separated by a known distance along some axis. Construction of a magnetic field gradiometer in the HDD industry is complicated, not only by the limited axial and radial space available for sensor placement, but also by the need to communicate measurements to the surface receiver by a magnetic field transmission. The lack of space makes it desirable to package beacon electronics elements as densely as possible, but the presence of the antenna's ferrite rod near a gradiometer's magnetic field sensors is known to be capable of disturbing the gradiometer's measurement capability. In the case of the most sensitive sensors, the proximity of a ferrite rod to any of the sensing elements can produce undesirable measurement degradation.
[0012] Further, conventional beacon antennas will be inside a beacon housing that attenuates the magnetic field because the beacon housing is conductive and magnetically permeable. To reduce this effect, slots are often provided in the beacon housing. However, limitations include differences in the strength based upon the orientation of the housing, attenuation, and may require specifically clocked housings for accurate measurements.
[0013] The present invention packages the antenna away from sensors and outside of the beacon housing. The invention may also be used with a downhole generator that may be integral with the beacon for power, which could be housed in a common housing. The beacon may be used with a single or dual-member drill string. The beacon could also be used with a drive shaft going through the beacon to drive a downhole tool such as in a coiled tubing application.
[0014] With reference now to the figures in general and FIG. 1 in particular, shown therein is a downhole tool 10 . The downhole tool 10 is connected on a first end 12 to a drill bit (not shown) and a second end 14 to a drill string 11 . As shown, the tool 10 is adapted to connect to a dual member drill string 11 comprising an inner member 11 a and an outer member 11 b, though a single member drill string may be utilized with the proposed invention without departing from its spirit. The tool 10 may connect to the drill string 11 at a threaded connection or other known connection at its second end 14 . The tool 10 comprises a front tool body 16 , a beacon assembly 18 , and an antenna assembly 20 . The tool 10 comprises a housing wall 21 which is preferably located about a periphery of the beacon assembly 18 but inside the antenna assembly 20 . The beacon assembly 18 may allow fluid to pass through the center portion of the tool 10 forming an internal passage 13 of the drill string 11 or with an annulus between the inner member 11 a and outer member 11 b of a dual member drill string.
[0015] The housing wall 21 preferably has a varying diameter creating a first portion 21 a and second portion 21 b, such that the diameter of the housing wall 21 when encasing the beacon assembly 18 (first portion 21 a ) is greater than the diameter of the housing wall when within the antenna assembly 20 (second portion 21 b ). A shoulder may be created between the first portion 21 a and the second portion 21 b, or the transition may be tapered or gradual. The housing wall 21 may comprise an opening, or feedthrough 104 ( FIG. 5 ) for the antenna coil 100 ( FIG. 5 ), to traverse between the antenna assembly 20 and the beacon assembly 18 .
[0016] The front toot body 16 allows fluid flow from within the drill string 11 to a drill bit or other tool as well as transmission of rotation from the inner member 11 a to the drill bit. The beacon assembly 18 comprises a magnet motor 22 and a generator assembly 24 . As relative rotation occurs between the inner member 11 a and outer member 11 b of the drill string 11 , components of the downhole tool 10 also rotate relative to one another due to connection made at stem weldment. An exemplar generator assembly 24 utilizing a dual-member drill string 11 may be found in U.S. Pat. No. 6,739,413, issued to Sharp, et. al., the contents of which are incorporated herein by reference.
[0017] The antenna assembly 20 comprises an antenna 26 and a protective casing 29 . The antenna 26 transmits signals generated by the beacon assembly 18 as will be described in further detail with reference to FIGS. 3-5 . The protective casing 29 is preferably a magnetically transparent sleeve, a material that has a relative permeability of substantially unity. The casing 29 may comprise cast urethane, plastics, ceramics, or other materials that provide structural protection but create little or no interference with the signal of the antenna 26 .
[0018] With reference now to FIG. 2 the beacon assembly 18 is shown in greater detail, The beacon assembly 18 may be rotationally locked to the inner member 11 a (not shown). The generator assembly 24 comprises stator poles 30 , bobbins 32 , and a back plate 34 . The stator poles 30 , when rotated relative to magnet motor 22 ( FIG. 1 ) through fluid flow or relative rotation of the inner 11 a and outer 11 b drill members, generate a current to power the tool 10 . Alternatively, power for the tool 10 may also be provided by wireline or batteries.
[0019] The beacon assembly 18 further comprises a sensor assembly 40 . The back plate 34 helps to isolate the generator assembly 24 from the sensor assembly 40 . The sensor assembly 40 comprises aboard 42 , a sensor 44 , and a program port 46 . The board 42 provides structural and electrical connectivity for the sensor 44 and program port 46 . The board 42 may be curved to match the shape of the beacon assembly 18 . The sensor 44 comprises one or more sensors for determining an orientation of the downhole tool 10 . Such sensors 44 may comprise one or more yaw, pitch, roll, tension, force, conductivity, or other sensors. For example, an accelerometer may be utilized. The program port 46 allows a user to access data and configure the sensors 44 . Further, while the use of sensors 44 is one advantageous use of the antenna assembly 20 ( FIG. 3 ), another transmission source could be utilized with the antenna assembly disclosed below.
[0020] The antenna assembly ( FIG. 3 ) may also connect to the beacon sensors 44 through port 46 , A locating key 48 may be utilized to lock the clock position of the beacon assembly 18 to the antenna assembly 20 ( FIG. 3 ). In this way, a feedthrough 104 ( FIG. 5 ) may be placed between the sensor assembly 40 and the antenna assembly 20 through the housing wall 21 ( FIG. 3 ). As shown, a center tube 49 passes through the beacon assembly 18 to provide fluid flow and optionally provide rotational torque from the drill string 11 ( FIG. 1 ).
[0021] With reference to FIG. 3 , the antenna 26 comprises an end support 50 , a support tube 52 , at least one ferrite rod 54 , a nonconductive tube 56 and a shield 58 . The end support 50 provides an insulating support for the antenna 26 within the tool 10 so that electromagnetic interference of the housing wall 21 at the ends of the antenna 26 is minimized. Further, any electromagnetic interference between the antenna 26 and sensors 44 is also minimized. The support tube 52 is disposed about the housing wall 21 and locates the ferrite rods 54 within the antenna assembly 20 . The shield 58 is preferably highly conductive, non-magnetic. Aluminum may be used in the shield 58 , as could other materials such as copper. Preferably, the shield covers the end support 50 . There may be a further insulator between the shield 58 and the housing wall 21 . The nonconductive magnetic field layer, or tube 56 is located between the shield 58 and ferrite rods 54 and insulates them from each other. Further, the tube 56 may be a non-magnetic material such as plastic. Without the nonconductive tube 56 or similar structure, the magnetic field would be pushed outward but some eddy currents would flow within the housing wall 21 . The tube 56 may be a hollow cylinder, or may be comprised of multiple pieces with nonconductive, non-magnetic properties.
[0022] The ferrite rods 54 are located between the plastic tube 56 and protective casing 29 and magnify signal strength of the beacon signals corresponding to readings of the beacon assembly 18 . A coiled antenna wire 100 ( FIG. 5 ) may be provided about the ferrite rods 54 to transmit the beacon signals. Further, as shown in FIG. 5 , an antenna wire 100 may be utilized without ferrite rods. The coiled antenna wire 100 is preferably a single layer to minimize its profile, but a multi-layer antenna may be used.
[0023] With reference now to FIG. 4 , the antenna assembly 20 is shown in cross section. The housing wall 21 is removed for clarity. As shown, the antenna assembly 20 comprises twenty five ferrite rods 54 , though other numbers of rods may be used. Additionally, the ferrite rods 54 themselves may be removed and elements of the housing wall 21 may be used with an antenna coil. The antenna coil 100 may be also utilized about the ferrite rods. In general, the arrangement of the antenna assembly 20 from inside to outside is housing wall 21 ( FIG. 3 ), shield 58 , tube 56 , ferrite rods 54 , antenna coil 100 ( FIG. 5 ), protective casing 29 . An insulating gap or material (not shown) may be utilized between the housing wall 21 and shield 58 . Further, the plastic tube 56 may be replaced with a layer of any non-conductive material, such as air.
[0024] In operation, the antenna assembly 20 of FIG. 4 operates when current passes through the antenna windings 100 to generate a magnetic field corresponding to beacon readings. The field passes through the tube 56 and permeates the shield 58 according to skin depth rules. The eddy current induced in the shield 58 will “push” the magnetic field out away from the tool 10 , minimizing power loss. The insulating gap (not shown) prevents eddy currents from reaching the housing wall 21 .
[0025] In FIG. 1 , the antenna assembly 20 and beacon assembly 18 are shown with linear displacement for clarity. One of skill in the art will appreciate that these assemblies may be placed at any location longitudinally relative to one another without critically impairing the spirit of this invention. In fact, the antenna assembly 20 may be disposed about a portion of the housing wall 21 that is disposed about the beacon assembly 18 .
[0026] With reference now to FIG. 5 , an alternative embodiment of the antenna assembly 20 is shown. The antenna assembly 20 comprises a housing wall 21 with a first, large diameter portion 21 a and a recessed, second portion 21 b. The recessed portion 21 b is covered, or filled, with a protective casing 29 . The antenna coil 100 is wrapped around the housing wall 21 and within the protective casing 29 . The protective casing 29 may comprise a urethane material or other magnetically transparent material. The antenna coil 100 is connected to the beacon assembly 18 ( FIG. 1 ) through the feedthrough 104 . The feedthrough 104 may comprise small radial holes made in the housing wall 21 .
[0027] One skilled in the art will appreciate that the embodiments contained herein may be modified without departing from the spirit of the invention contained herein. For example, alternative sensors or antenna arrangements, and materials may be utilized. | A beacon assembly located at a downhole end of a drill string proximate a boring tool. The beacon assembly transmits data to an above-ground receiver. The beacon has a housing with a housing wall located between its sensors, such as gradiometers, accelerometers, and other orientation sensors, and an antenna assembly. The antenna assembly has a protective covering made of electromagnetically transparent material. | 7 |
BACKGROUND
The invention is based on a procedure for operating a particle filter that is arranged in the exhaust gas area of a combustion engine and on a device for implementing the procedure.
DE 199 06 287 A1 describes a procedure for operating a particle filter of a combustion engine, which is regenerated if required. Without a conditioning of the particles the particles oxidize at a temperature of about 550° C. The required particle ignition temperature can be achieved with a reagent, for example uncombusted hydrocarbons, which is inserted into the exhaust gas area of the combustion engine, reacts exothermally at the catalytically working surface and therefore increases the exhaust gas temperature upstream in front of the particle filter.
In certain operating conditions of the combustion engine the case may occur that the regeneration runs uncontrollably fast because of the increased oxygen content of the exhaust gas. Due to the strong exothermic oxidization of the particles an inadmissibly high temperature increase in the particle filter may occur. In order to avoid such a condition DE 103 33 441 A1 suggests to influence the particle burning rate with the aid of the exhaust gas lambda. A nominal value for a lambda signal or a nominal value for a change of the lambda signal is predefined, which is compared to the measured exhaust gas lambda. Depending on the deviation between the nominal and the actual value a control signal is provided for a control element, which influences the oxygen concentration in the exhaust gas. An exhaust gas recirculation valve, a throttle valve etc can for example be provided as control element.
DE 101 08 720 A1 also describes a procedure and a device for controlling a combustion engine, which contains a particle filter, which is arranged in the exhaust gas area and which is regularly regenerated. Based on an operating parameter of the combustion engine and/or the particle filter a parameter is determined, which characterizes the intensity of the exothermic reaction in the particle filter during the regeneration. If the intensity parameter exceeds a threshold value, measures are taken for reducing the oxygen concentration in the exhaust gas in order to reduce the particle burning rate.
DE 199 06 287 A1 describes a further procedure for controlling a combustion engine, in whose exhaust gas area a particle filter is arranged. The temperature increase for starting the regeneration of the particle filter is achieved with a reagent, which is inserted into the exhaust gas area of the combustion engine upstream in front of the particle filter. Fuel is provided as reagent, which reacts in the exhaust gas area exothermally, for example on a catalytically working surface of a catalytic converter. The fuel gets into the exhaust gas area by adjusting the fuel injection timing, which causes an incomplete combustion of the fuel.
The insertion of fuel into the exhaust gas area of the combustion engine can be carried out according to DE 10 2004 033 414 A1 alternatively or additionally to the adjustment of the fuel injection timing by at least one fuel after-injection. Provided are at least a first and at least a second fuel after-injection. The first fuel after-injection is a fuel after-injection that is leaned on a main-injection, at which the injected fuel only combusts partially, so that uncombusted fuel gets into the exhaust gas area. The second fuel after-injection is a late fuel after-injection, at which the fuel does not combust anymore and gets mostly into the exhaust gas area.
The load condition of a particle filter can for example be determined according to DE 199 06 287 A1 with the aid of the determination of the difference pressure occurring at the particle filter.
DE 101 18 878 A1 describes a procedure for operating a combustion engine, at which an overrun cut-off is provided in order to save fuel. The overrun cut-off becomes active if the engine speed of the combustion engine lies above an engine speed threshold value and if simultaneously there is no load demand. A cooling off of a catalytic converter that is arranged in the exhaust gas area of the combustion engine is thereby avoided, in that the exhaust gas recirculation rate is increased during the overrun cut-off.
SUMMARY
The invention is based on the task to provide a procedure for operating a combustion engine, in whose exhaust gas area a particle filter is arranged, and a device for implementing the procedure, which avoid the occurrence of an inadmissibly high temperature in the particle filter.
The task is solved by the characteristics stated in the independent claims.
The procedure according to the invention for operating a combustion engine, in whose exhaust gas area a particle filter is arranged, which is freed from the stored particles during a regeneration, at which a measure for a load of the combustion engine is compared to a load threshold value and at which an overrun cut-off of the combustion engine is carried out, at which the fuel metering is completely suppressed, if the measure for the load of the combustion falls below the load threshold value and if the engine speed of the combustion engine lies above an engine speed threshold value, provides that the load threshold value is higher than zero and that the load threshold value is determined at least depending on a particle filter regeneration signal.
With the aid of trials it can be shown that during the reduction of the fuel amount that is provided to the combustion engine per work cycle of a cylinder, the combustion process becomes more and more instable up to a point, at which no combustion at all takes place.
An unstable combustion can in particular occur in connection with fuel after-injections. Fuel after-injections are distinguished as main combustion fuel after-injection, at which the after-injected fuel is mostly still combusted in the cylinder, and late fuel after-injections, with which specifically uncombusted hydrocarbons are inserted into the exhaust gas area of the combustion engine, which should react exothermally. Unstable conditions can in particular occur at the main combustion fuel after-injection at low fuel amounts, which increase if a comparably low fuel main-injection is predefined. A low fuel amount is connected to an increase of the possibility for combustion dropouts.
The procedure according to the invention avoids an uncontrollable oxygen input into the exhaust gas area upstream in front of the particle filter. A hazardous situation for the particle filter can in particular be given during a regeneration. During a regeneration an uncontrollable oxidization of the particles may occur at an excessive oxygen supply, which can cause an overheating of the particle filter. The excessive oxygen supply can also cause an undesired oxidization of combustible exhaust gas components, connected with an increase of the exhaust gas temperature, which also determines the particle filter temperature as input parameter.
The procedure according to the invention enables an adjustment of the threshold for the overrun cut-off by influencing the load threshold value depending on a particle filter regeneration signal, which signalizes whether the particle filter is regenerated or not and which contains an information about the course of the regeneration if necessary.
If the regeneration signal is not present the load threshold value can be determined as lower at an overrun cut-off. If the regeneration signal is present, an uncontrollable oxygen input into the exhaust gas area of the combustion engine is avoided at an overrun cut-off according to the procedure of the invention. If the regeneration signal is not only a digital signal, which signalizes the regeneration of the particle filter, but an information about the regeneration course, for example a measure for the particle burning rate, the load threshold value can be determined variably.
Advantageous improvements and configurations of the procedure according to the invention arise from the dependent claims.
One embodiment provides that the load threshold value depends on at least one parameter of the particle filter. Preferably a measure for the load status of the particle filter and/or the particle filter temperature is provided as parameter.
One embodiment provides that the load threshold value depends on at least one operating parameter of the combustion engine. The engine speed of the combustion engine and/or its operating temperature are preferably provided as operating parameter.
One embodiment provides that the load threshold value depends at least on one parameter of the exhaust gas. Preferably the exhaust gas flow and/or the exhaust gas temperature is provided as exhaust gas parameter.
One embodiment provides that the load threshold value depends on the engaged gear of a transmission and/or on the weight of a motor vehicle, in which the combustion engine is used as drive motor. With these measures the driving comfort is affected as little as possible.
One embodiment provides that during the overrun cut-off at least a further measure for suppressing an oxygen input into the exhaust gas area of the combustion engine is undertaken besides the suppression of the fuel metering. The complete closing of a throttle valve that is arranged in the intake area of the combustion engine can for example be provided. One embodiment provides that the transit from the fuel injection to the overrun cut-off and/or from the overrun cut-off to the fuel injection takes place according to a default time course. With this measure the driving comfort can be influenced during the transitions.
The device according to the invention for operating a combustion engine concerns at first a control unit, which is customized for implementing the procedure.
The control unit contains preferably at least one electric storage, in which the steps of the procedure are stored as computer program.
One embodiment provides that a throttle valve is arranged in the intake area of the combustion engine, which is closed at least during the overrun cut-off for suppressing the oxygen input into the exhaust gas area of the combustion engine.
Further advantageous improvements and configurations of the procedure according to the invention arise from further dependent claims and from the following description.
BRIEF DESCRIPTION OF THE DRAWING
The FIGURE shows a technical environment, in which a procedure according to the invention runs.
DETAILED DESCRIPTION
FIG. 1 shows a combustion engine 10 , in whose intake area 11 an air detection 12 as well as a throttle valve 13 and in whose exhaust gas area 14 a first temperature sensor 15 and a second temperature sensor 17 that is assigned to a particle filter 16 are arranged. An exhaust gas flow ms_abg occurs in the exhaust gas area 14 .
The air detection 12 provides an air signal ms_L to a control unit 20 , the combustion engine 10 an engine speed n, a first temperature sensor 15 an exhaust gas temperature te_vDPF upstream in front of the particle filter 16 and the second temperature sensor 17 a particle filter temperature te_DPF.
The control unit 20 provides a throttle valve signal dr to the throttle valve 13 and a fuel signal m_K to a fuel metering device 21 that is assigned to the combustion engine 10 .
The control unit 20 contains a fuel signal determination 30 , which is supplied with the air signal ms_L, the engine speed n, a torque nominal value Md_Soll and signals of a first and second fuel after-injection Po_I 1 , Po_I 2 and which provides the fuel signal m_K as well as the throttle valve signal dr.
The fuel signal determination 30 contains an overrun cut-off determination 31 , which provides a comparator 32 , which is supplied with the air signal ms_L, the engine speed n, the torque nominal value Md_Soll as well as a load threshold value L_S and which provides a signal for a overrun cut-off SA.
The signal for the overrun cut-off SA is provided to a throttle valve signal determination 33 as well as a ramp signal determination 34 .
The control unit 20 contains furthermore a load threshold value determination 35 , which is supplied with a signal of a regeneration Reg of the particle filter 16 , a signal of a particle filter load status m_P, the engine speed n, the exhaust gas flow ms_abg, the particle filter temperature te_DPF, the mass_M_KfZ of a motor vehicle, an information about a gear g, a combustion engine temperature te_Mot as well as an ambient air temperature te_Lu and which provides the load threshold value L_S.
The procedure according to the invention works as follows:
The fuel signal determination 30 that is contained in the control unit 20 determines the fuel signal m_K for example depending on the air signal ms_L, on the engine speed n and on the torque nominal value Md_Soll as well as on other, not further labeled input parameters if necessary. The air signal ms_L provides the air detection 12 , which detects the air mass or air volume that is supplied to the combustion engine 10 .
The torque nominal value Md_Soll is for example derived from the position of a not further shown accelerator pedal of an also not further shown motor vehicle, in which the combustion engine 10 is arranged as drive motor.
The fuel signal determination 30 considers furthermore the first and if necessarily provided second fuel after-injection Po_I 1 , Po_I 2 , whereby the signals are supplied by a not further shown regeneration control.
From time to time the particle filter 16 that is arranged in the exhaust gas area 14 has to be regenerated from the stored particles. The regeneration takes place for example by a burn-up of the particles, which begins without a conditioning of the particles at temperatures above about 550° C. at present oxygen.
The required starting temperature for the burn-up of the particles can for example take place with a passive heating of the particle filter 16 by the exhaust gas temperature te_vDPF upstream in front of the particle filter 16 . The exhaust gas temperature te_vDPF is detected by the first temperature sensor 15 and/or determined with the aid of a temperature model.
The temperature increase in the exhaust gas area 14 is for example obtained by an exothermic reaction of a reagent with oxygen. Fuel qualifies best as reagent, which is also supplied to the combustion engine 10 .
The reagent can be supplied by inner-motorized measures, as for example a decline of the combustion for example by a late shift of the fuel main injection and/or by the at least one fuel after-injection Po_I 1 Po_I 2 .
After initiating the particle filter regeneration the burning rate of the particles can be influenced by the oxygen concentration in the exhaust gas area 14 upstream in front of the particle filter 16 . The particle burning rate has a significant influence upon the particle filter temperature te_DPF. The particle filter temperature te_DPF depends not only on the particle burning rate but also on the exhaust gas temperature to vDPF upstream in front of the particle filter 16 and in particular on the exhaust gas flow ms_agb. The exhaust gas flow ms_abg is for example an exhaust gas mass flow or an exhaust gas volume flow.
The particle filter temperature te_DPF is detected by the second temperature sensor 17 and/or can be determined with the aid of a temperature model. The second temperature sensor 17 can be arranged directly at the particle filter 16 or in particular directly downstream after the particle filter 16 .
During a fuelled operation of the combustion engine 10 the oxygen concentration in the exhaust gas area 14 upstream in front of the particle filter 16 can be influenced by a not further shown lambda regulation. In special operating conditions of the combustion engine 10 an overrun cut-off SA of the combustion engine 10 can be carried out, at which the fuel supply to the combustion engine 10 is completely stopped. Such operating conditions are present if the engine speed n lies above a not further shown engine speed threshold value and if simultaneously the load of the combustion engine 10 equals zero.
A measure for the load of the combustion engine 10 is for example the torque nominal value Md_Soll. As measures for the load of the combustion engine 10 also other information can be used as for example an internal torque value or the fuel signal m_K itself. The load of the combustion engine 10 can for example be furthermore predefined by an idle-speed controller. In the following only the torque nominal value Md_Soll is mentioned as measure for the load Md_Soll of the combustion engine 10 .
It has shown in trials that in particular at a low fuel metering into the individual cylinders of the combustion engine irregularities at the combustion of the fuel up to combustion dropouts can occur. Thereby the oxygen concentration and the concentration of uncombusted hydrocarbons in the exhaust gas area 14 can only be controlled very difficult.
An unstable combustion occurs in particular with a fuel after-injection Po_I 1 , which is attached to a fuel main-injection and which should at least partially burn in the cylinder. At low loads Md_Soll the level of the fuel amount that is supplied to the combustion engine 10 is overall reduced, so that an additional reduction of the fuel amount that is provided to the fuel main injection occurs by a relative shift of the fuel amount to the fuel after-injection, accompanied by an increase of the possibility for combustion dropouts.
An operating condition that is critical for the particle filter 16 is in particular given if the particle filter 16 is regenerated and the oxygen concentration in the exhaust gas area 14 upstream in front of the particle filter 16 increases uncontrollably. Due to the available oxygen the particle burning rate increases, accompanied by the danger of an overheating of the particle filter 16 .
According to the invention it is provided to compare at least one measure for the load Md_Soll of the combustion engine 10 with the load threshold value L_S during an overrun cut-off of the combustion engine 10 .
The overrun cut-off SA lies above a not further shown engine speed threshold value. Only in that case, an overrun cut-off SA is allowed. Furthermore it is checked during the overrun cut-off determination 31 whether the measure for the load Md_Soll of the combustion engine 10 falls below the load threshold value L_S. the checking takes place in the comparator 32 . Only if both conditions are simultaneously fulfilled the overrun cut-off SA is induced.
The signal that displays the overrun cut-off SA is provided to the throttle valve determination 33 and to the ramp signal determination 34 in the shown embodiment.
According to the invention the load threshold value L_S is determined depending on the regeneration signal Reg, which is provided by a not further shown regeneration control. The regeneration signal Reg can be a digital signal, which only shows that a regeneration of the particle filter 16 takes place or not. Preferably the regeneration signal Reg additionally contains information for example about the particle burning rate and/or other information about the regeneration of the particle filter 16 . In that case the load threshold value L_S can be pre-specified variably depending on the regeneration signal Reg. in particular a load threshold value L_S greater than zero is always pre-specified.
The load threshold value L_S is increased during a miming regeneration in order to increase the safety towards incomplete combustions in the individual cylinders of the combustion engine 10 and the therefore possible uncontrollable increase of the oxygen concentration in the exhaust gas area 14 upstream in front of the particle filter 16 . Accordingly in less critical operating situations of the particle filter 16 a lowering of the load threshold value L_S can be carried out. In particular a variable regeneration signal Reg enables an intervention by lowering the load threshold value L_S, whereby for example a miming regeneration of the particle filter 16 has not to be interrupted.
The load threshold value L_S can depend on the load status m_P of the particle filter 16 with particles. The load threshold value L_S is increased with an increasing load status m_P.
The load threshold value L_S can depend on the engine speed n of the combustion engine 10 , whereby the load threshold value L_S is increased with a sinking engine speed.
The load threshold value L_S can depend on the exhaust gas flow ms_abg, whereby the load threshold value L_S is increased at a low exhaust gas flow ms_abg. The load threshold value L_S can depend on the particle filter temperature te_DPF, whereby the load threshold value L_S is increased with an increasing particle filter temperature te_DPF.
The load threshold value L_S can depend on the mass M_KfZ of a motor vehicle, in which the combustion engine 10 is used as drive motor. With an increasing mass M_KfZ of the motor vehicle the load threshold value L_S can be increased, because the start of the overrun cut-off SA or the resumption of the fuelled operation of the combustion engine 10 are less noticeable at a higher mass M_KfZ.
The load threshold value L_S can depend on the engaged gear g of a transmission, whereby the load threshold value L_S is lowered at a low gear g.
The load threshold value L_S can furthermore depend on the temperature of the combustion engine te_Mot, whereby the loaf threshold value L_S is lowered at a high combustion engine temperature te_Mot.
Finally the load threshold value LS can depend on the ambient air temperature to Lu, whereby the load threshold value L_S is lowered at high ambient air temperatures to Lu.
The transition from the fuelled operation of the combustion engine 10 to the overrun cut-off SA and/or from the overrun cut-off SA to the fuelled operation can take place abruptly. An increase of the driving comfort can be obtained with a specifically pre-specified timely transition. With the ramp signal determination 34 the fuel signal m_K can be lowered to zero according to a predefined course of curve, for example linearly, from the last determined fuel signal m_K after falling below the load threshold value LS during the overrun cut-off SA or be booted up correspondingly from zero to the reset value of the fuel metering.
According to an embodiment it is provided that during the overrun cut-off SA further measures are undertaken, which influence an input of oxygen into the exhaust gas area 14 upstream in front of the particle filter 16 . One measure provides for example the complete closing of the throttle valve 13 that is arranged in the intake area 11 of the combustion engine 10 . During the overrun cut-off SA the throttle valve signal determination 33 pre-specifies the throttle valve signal dr for closing the throttle valve 13 . | A procedure for the operation of an internal combustion engine is disclosed, in whose exhaust gas area a particle filter is arranged which is freed from the stored particles during a regeneration. A measure for a load of the combustion engine is compared to a load threshold value. An overrun cut-off, at which the fuel metering is completely suppressed, is carried out if the measure for the load falls below the load threshold value and if the engine speed of the combustion engine lies above an engine speed threshold value. The load threshold value that has been determined to a value higher than zero is further dependant on the particle filter's regeneration signal. The procedure aims to prevent the overheating of the particle filter during its regeneration. | 5 |
BACKGROUND OF THE INVENTION
The present invention relates to a plug-in quartz infra-red radiator with a housing and, disposed therein, at least one heating element, with electrical connections, plug-in connections on the back of the housing and with a heat-resistant insulating holder for the heating element or heating elements in the housing.
Such a quartz infra-red radiator is known from DE-OS 36 19 919. In the case of the prior art quartz infra-red radiator, both mechanical and also electrical plug-in connections are disposed independently of one another on the back of the housing. It is true that the plug-in facility of the quartz infra-red radiator, when compared with the hitherto conventional complicated wiring arrangement, does already provide tremendous advantages, yet with the prior art plug-in quartz infra-red radiators the electrical connections of the heating elements are still in conventional manner led out of an insulating support for the heating elements to the plug-in contacts disposed on the back of the housing where they are connected to the associated part of a plug or of a socket. The electrical plug-in connection on the back of the housing must thereby, as a rule, provide a heat-resistant electrical insulation for the connection to the electrical connections of the heating elements and which, in accordance with conventional requirements in terms of heat resistance, insulating capacity and mechanical properties, constitutes the provision of a ceramic housing for the plug-in connection. The disposition and attachment of such a plug-in connection with a ceramic housing on the back of an infra-red radiator means additional expense when producing the quartz infra-red radiator which would otherwise have on the back purely a row of ceramic sleeve insulated connecting wires.
In contrast, the present invention is based on the problem of providing a plug-in quartz infra-red radiator having the features mentioned at the outset but which, when compared with the prior art plug-in quartz infra-red radiators, can be produced more easily and at a more competitive price.
SUMMARY OF THE INVENTION
This problem is resolved in that the heat-resistant insulating holder comprises a space to accommodate at least a part of a plug-in connection and at least one aperture for leading through a part of a plug-in connection which is not accommodated in the space and which preferably protrudes therefrom at the back of the housing.
Consequently, the function of a likewise heat-resistant holder which in any event is provided for the heating elements of the quartz infra-red radiator is advantageously combined with that of a holder for the plug-in connection so that a part of the plug-in connection is accommodated and supported in the space provided for it in the heating element holder, while another part of the plug-in connection extends from this space through the aperture which is likewise provided on the holder, emerging at the back of the housing so that this projecting part can be fitted together with a matching counterpart which is for example disposed on an assembly plate. However, it is also possible for a part of a plug-in connection to extend from the assembly plate in the direction of the infra-red radiator and which, when connected to the infra-red radiator, is pushed into the aperture so that a connection is established with the part of the plug-in connection which is housed in the space of the holder.
Certainly, an embodiment of the invention is preferred in which the projecting part of the plug-in connection and the part of the plug-in connection which is accommodated in the space of the holder are connected to each other in one piece.
In particular, an embodiment of the invention is preferred in which these plug-in connection parts form a flat plug which is angled over to an L-shape, of which the first leg is completely housed in the space in the holder which is provided for it while its second leg extends through the aperture in the holder, emerges at the back of the housing and can be plugged together with a matching counterpart.
By reason of the different aforesaid possibilities, therefore, the term "plug-in connection" within the meaning of this application must be so interpreted that it covers both the connection consisting of a socket and a plug and also a plug or a socket by themselves, in so far as they consist of a part which is accommodated in the space of the holder and a part which projects from the holder and also from the back of the housing.
It is expedient if the holder according to the present invention has space for parts of two plug-in connections. It is well known that an electrical heating element needs two electrical connections which expediently end at one and the same holder and which merge into the two plug-in connections disposed on this holder. Of course, it is however also possible in the case of a quartz infra-red radiator having a plurality of holders for heating elements to provide one of the above-mentioned plug-in connections at each of these holders. Also the preferred embodiment of an infra-red radiator according to the present invention has, disposed on opposite side walls of a housing, two holders for heating elements, although only one of these holders has both the necessary plug-in connections. Regardless of this, however, the two oppositely disposed holders or parts thereof may be identically formed and may have the appropriate space to accommodate plug-in connections without plug-in connections having to be provided also on both holders. This may be sensible particularly on production grounds, since in this way it is possible to reduce the number of parts which have to be differently produced.
It is particularly advantageous if according to the invention the holder on one side of the housing is made in two parts, both parts being in the readily installed state flush with one another and having in their bearing surfaces recesses which are opposite one another, so defining the space for the parts of plug-in connections. Where such an embodiment is concerned, both parts of a holder are separated and then the corresponding parts of a plug-in connection are simply inserted from the bearing surface into the recesses provided therein and the second part of the holder has its recesses so fitted over them that the parts of the plug-in connection are accommodated in the space formed by the oppositely disposed recesses. It is also expedient if from the recesses at least one respective slot extends as far as that side of the parts of the holder which are at the back of the housing, so providing an aperture through which it is possible to lead a part of the plug-in connection from the space to the outside of the housing.
Also the aforesaid L-shaped angled-over flat plug can have one leg so inserted into the corresponding space from the bearing surface of one of the parts, the other arm of the L-shaped angled-over plug then extending outwardly through the slot. As soon as the two parts of the holder, with the inserted plug-in connection parts bear on one another, they are inserted into the housing and are fixed in this condition.
Preferably, the holder consists of ceramic material since ceramic is a very readily heat-resistant and at the same time electrically readily insulating material which has sufficient mechanical strength both to accommodate and support the heating elements and also the plug parts.
If the housing has a continuous rear wall, then it goes without saying that at the height of the holder it is necessary to provide at least one aperture in the rear wall of the housing, it being particularly advantageous if at least one lug extends from the edge of the aperture and parallel with and at a distance from the opposite side walls of the housing and into the interior of the housing. This lug may be used for attachment of the holder.
It is particularly advantageous if the distance between the lug and a side wall corresponds to the thickness of the holder, the aperture in the rear wall of the housing being disposed between the lug and this side wall. The holder can be so fittingly inserted between the lug and a side wall of the housing, a part of its side which is towards the rear wall lying exactly over or under the aperture in the rear wall of the housing, so that it is possible at this point to provide plug parts which project beyond the housing.
According to a preferred embodiment of the invention, the holder comprises at least one continuous transverse aperture which extends substantially parallel with the rear wall of the housing and the heating element or elements. Through such a transverse aperture may extend fixing elements to the side wall of the housing or to a lug. In such a case, it is particularly suitable if the lug and the side wall comprise apertures aligned with each other and with the continuous transverse aperture so that in this way the holder can easily be rigidly riveted on the lug and the side wall of the housing. It is possible thus advantageously to avoid the ends of the rivets pressing directly on the holder which particularly in the case of ceramic holders can easily result in their breaking. In the case of the aforementioned preferred embodiment, however, the two ends of the rivet engage the side wall or a lug, being pressed on the intermediate holder while at the same time distributing over a relatively large area of the holder the forces exerted by the rivet. In addition, the transverse aperture in the holder can also be reinforced by a metal sleeve.
Where the two-part embodiment of the holder is concerned, it is particularly advantageous if the part bearing on the side wall of the housing is in the direction at right-angles to the rear wall of the housing wider than the other part of the holder and if it has in its projecting portion a housing to accommodate heating elements.
The space to accommodate parts of the plug-in connection then lies in the region in which the two parts of the holder bear on each other while independently of this, there is in the projecting portion of one part of the holder a housing for the heating elements. This part which bears on the side wall and which has the housing for the heating elements can then, regardless of the disposition of parts of the plug-in connection, also be used as a conventional holder for heating elements. If, then, it is desired to dispose plug elements on the holder, then simply the second part of a holder is added which must be disposed in the region in which it is adjacent the rear wall of the housing, since plug parts ought to extend through the rear wall of the housing. The space to accommodate the plug-in connection and the corresponding parts of the holder therefore lie in the region between the heating elements and the rear wall of the housing.
Preferably, the electrical connections of the heating elements are connected directly to parts of plug-in connections which are accommodated in the space of the holder, preferably by welding. In any event, the connection must be sufficiently heat-resistant and electrically safe. However, it has been found that heat dissipation through such plug-in connections is sufficiently good so that the temperatures at the plug contacts remain below 300° C. so that it is possible to produce a plug-in connection with commercially available flat plugs.
In addition to the electrical plug-in connection, the preferred embodiment of the invention also has, disposed on the rear wall of the housing, a mechanical plug journal which can be plugged in by means of a resilient plug socket which is disposed for example at a suitable distance from the electrical plug parts on an assembly plate.
For the electrical connection of a plug-in connection part which is accommodated in the holder, with a heating element, there are of course also provided recesses, connecting passages, apertures or the like between the housing for the heating elements and the space in the holder which accommodates the plug-in connection part.
Further advantages, features and possible applications of the present invention will become clearly apparent from the ensuing description of a preferred embodiment and of the associated drawings in which:
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 shows a longitudinal section through a quartz infra-red radiator,
FIG. 2 is a view of the infra-red radiator from the front,
FIGS. 3a-f show various views of a first holder part,
FIGS. 4a-e show various views of a second holder part,
FIGS. 5a-c show various views of the housing,
FIG. 6 shows a perspective view of a flat plug for insertion in to a holder and
FIGS. 7a-c show various views of a counterpart for the flat plug according to FIG. 6.
DESCRIPTION OF THE PREFERRED EMBODIMENT
FIGS. 1 and 2 show heating elements 2 which consist of quartz tubes in which there is a filament which consists of an electrical heating wire. The quartz tubes or heating elements 2 are supported in recesses or holders 16 provided in the parts 6' of a holder 6. The parts 6' of the holder 6 are disposed on oppositely disposed side walls 12 of the housing 1 of a quartz infra-red radiator.
The holder 6 shown on the right-hand side of FIG. 1 consists of two parts 6', and 6", the part 6' being in the direction at right-angles to the bottom 15 of the housing 1 broader or higher than the part 6" so that the heating elements 2, extending beyond the part 6", project into the housing 16 of the part 6'. Extending transversely through the parts 6' and 6" are bores 13, 13' which are substantially parallel with the heating element 2. Around the bore 13, the part 6' has a cylindrical projection 19 which engages in fitting manner into a radial widened out part of the bore 13' at the part 6" so that after engagement the two parts 6' and 6" are fixed in relation to each other. Disposed in the transverse aperture 13 of the part 6' is a metal sleeve 18 which has a flange projecting beyond the extension 19 so that the part 6' can be directly attached by a rivet to the side wall 12 of the housing 1.
In the assembled state, the two-part holder 6 is inserted between a side wall 12 and a lug 11 which is bent upwardly from the bottom 15 of the housing 1 so that the parts 6' and 6" are in rigid engagement with one another. It is likewise possible to provide a rivet for fixing the holder 6, passing it through the bores 13' and 13 as well as through the aligned apertures 14, 14' on the housing 1 or lug 11.
FIG. 2 shows quite a number of heating elements 2 can be disposed beside one another in a housing 1 of a quartz infra-red radiator.
FIGS. 3a-f show various views or sectional views of the part 6' of the holder 6. In FIG. 3a, the part 6' is shown from the side which bears on the side wall 12. A more accurate impression is provided by the view in FIG. 3c which is a view of the part 6' seen from the inside of the housing 1. Diagrammatically shown are heating elements 2 which are in the housing 16 which can also be seen in cross-section in FIGS. e and f. The housing 16 is connected by a passage 17 to the recess 7' or the slot 8' which, in the completely installed state, are opposite corresponding recesses 7" and 8", so forming a space 7 and an aperture 8 for accommodating and leading through parts of a plug-in connection. Extending inside the heating element 16 are conventionally series connected coiled electrical heating wires the terminal connections of which are passed through the passage 17 to in each case an arm 5' of a plug-in connection 5 to which they are welded, as shown in FIG. 6. The plug-in connection 5 has its arm 5' in the recess 7' while its arm 5" projects into the recess 8' while its flat plug part protrudes from the slot 8' of the part 6 in the view in FIG. 3c rightwardly. The part 6' is in mirror symmetrical relationship of a median plane extending horizontally in respect of FIG. 3c. Therefore, to the right and left of this plane, there are in each case a recess 7' and a slot 8' as well as a passage 17 to accommodate the plug-in connection 5 and the electrical connections 3.
FIG. 4 shows the part 6' of the holder 6 which, as can also be seen in FIG. 1, is narrower than the part 6'. However, also the part 6" like the part 6' has mirror symmetrically disposed recesses 7" and slots 8" which in the completely assembled state are opposite the corresponding recesses 7' and slots 8' in the part 6' so forming the cavity 7 or the aperture 8 as indicated by broken lines in FIG. 4d. The space accommodates the arm 5' of the plug-in connection 5 while the arm 5' extends outwardly through the aperture 8. FIGS. 4a-d show clearly the transverse apertures 13', FIG. 4b furthermore showing that the already mentioned radial widening of the bore 13' is not exactly cylindrical but is slightly conical and so facilitates inter-fitment of the parts 6' and 6".
FIGS. 5a-c show only the housing 1. It can be seen that two apertures 10 are stamped out of the bottom of this, the material of the bottom 15 of the housing which is on the farthest inwards edge of the aperture 10 not being completely stamped off but remaining in the form of a lug bent over at an angle of substantially 90° to the bottom 15 of the housing 1. The lug comprises a bore 14' which is aligned with a bore 14 provided in the side wall 12. Also the side wall opposite the side wall 12 comprises a corresponding bore for a riveted attachment of the part 6' while in the space between the lugs 11 and the side wall 12 the assembled parts 6' and 6" can be inserted in a substantially fitting manner.
The peg or plug-in projection 4 shown in FIG. 1 can be constructed either in the form an otherwise commercially available retaining peg or it may be provided with an external screw thread so that it can be screwed into the interior of a retaining peg which is provided with a corresponding internal screw thread. Normally, such retaining threads have in the bottom a hexagonal projection so that they can easily be screwed onto an appropriate screw-threaded peg. Such a retaining peg furthermore has a point for insertion between spring clips and a tapering neck behind the conical point so that the retaining peg is gripped with a predetermined force by appropriate retaining clips engaging the restriction which is thus formed.
Mostly, quartz infra-red radiators are disposed in a relatively large number on a mounting plate so that on the mounting plate, arranged in an appropriate grid pattern, it is possible to provide spring clips for such retaining pegs and plug-in projections for the electrical plug-in connection parts 5" which project from the apertures 8 and 10 at the back of the housing. Such an electrical plug-in connection is shown in FIG. 7 where the flat plug part 5' is pushed into the space 20 between the rear wall 21 and the bent over contact flanks 22 of a plug-in connection 23. For its part, the plug-in connection 23 has at the other end three further flat plug connections which can be used both for further contacting and wiring of a plurality of infra-red radiators inter se but they can at the same time also serve as cooling surfaces to dissipate heat which passes from the heating elements 2 via the plug-in connection 5 to the plug-in connection 23.
Compared with the prior art plug-in infra-red radiators, the new quartz infra-red radiator is more simple in construction and more easily manufactured. It is only necessary somewhat to re-configure the holders 6 which are in any case required for the heating elements 2 so that they can serve at the same time as holders for plug-in connections 5. | A quartz infra-red radiator comprises a housing (1) and has disposed therein at least one heating element (2), electrical connections (3), plug connections (4, 5) on the back of the housing and with a heat-resistant insulating holder (6) for the heating element. In order to produce such a plug-in quartz infra-red radiator more easily and at a more competitive price, the heat-resistant insulating holder (6) comprises a space (7) to hold at least a part of a plug-in connection (5) and at least an aperture through which it is possible to pass a part of a plug connection (5) which is housed in the space (7) and which protrudes from the housing (1). | 7 |
This is a continuation of application Ser. No. 294,066 filed Oct. 2, 1972, now abandoned.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to an apparatus for focusing ultrasonic waves in a focal line to obtain good focusing of the sound field including good lateral resolution over a considerable depth.
2. Description of the Prior Art
Ultrasonic methods are becoming increasingly important in technology and medicine, for example, in material testing or in medical diagnosis. One known method is echo sounding, in which a sound head emits an ultrasonic pulse and the pulse reflected from an obstacle is received by a different sound head or the same sound head. The distance between the transmitter/receiver and a reflecting object can be determined from the time elapsing before the echo is received.
A measure of the accuracy of an echo-sounding method is the longitudinal resolution, i.e. in the direction of the sound waves, and the lateral resolution, i.e. at right angles to the longitudinal direction. When an ordinary conventional transducer is used, a relatively good longitudinal resolution can be obtained, but the lateral resolution is inadequate because of the relatively large diameter of the ultrasonic beam. If the diameter of the sound head is reduced, the beam has a wide divergence owing to diffraction phenomena. An improvement can be obtained by weakly focusing the beam so that its diameter becomes a minimum at the center of the object under observation. The minimum diameter must not be made too small, however, since otherwise the beam divergence again becomes too large. Typically, a beam diameter of 1-2 cm is obtained if a frequency of 2 MHz is to be used for observation over a depth of 20 cm.
A much better lateral resolution can be obtained if the ultrasonic beam is focused with a wide-aperture system. The lateral resolution may be in the order of magnitude of the wavelength, i.e. about 0.75 mm in the case of 2 MHz. This good lateral resolution is obtained, however, over only a very small depth, i.e. also approximately one wavelength.
It will therefore be clear that the disadvantage of the prior-art-echo-sounding methods is due to the fact that an improvement in lateral resolution is always accompanied by a reduction of the depth over which it can be obtained.
SUMMARY OF THE INVENTION
The object of the present invention is to obtain good focusing of the sound field and hence good lateral resolution over a considerable depth. A sound field which is at least partly convergent and which has an annular cross-section is produced preferably with an ultrasonic optical system comprising at least one rotation-symmetrical, non-spherical reflection or refraction surface. Examples of rotation-symmetrical, non-spherical surfaces are conical or cylindrical surfaces or combinations thereof with spherical surfaces. Since acoustic lenses are usually highly reflecting or absorbent, it is advantageous to use reflecting surfaces, i.e. acoustic mirrors.
A sound field of this type can also be produced with an annular transmitter transducer, the receiver transducer advantageously also being annular and, if required, the transmitter transducer is also used for reception.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows an ultrasonic head comprising an optical system containing a non-spherical mirror.
FIG. 2 shows an arrangement with a hollow cylinder as optical system diagrammatically; and,
FIG. 3 is a section of an annular ultrasonic transducer having a conical radiation surface.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The ultrasonic head illustrated in FIG. 1 comprises a commercially available ultrasonic transducer 1, which is disposed in a substantially cylindrical housing 2. In the present case, the diameter of the transducer comprising a piezoelectric crystal, is about 20 mm. The transducer 1 is retained by a screw cap 3 and a shoulder 4 on the inner wall of the housing, the screw cap to enable the transducer 1 to be readily removed when desired. On the side remote from the screw cap 3, the housing is closed by an ultrasonic condenser 5 consisting of a material suitable for ultrasonic lenses, in this case acrylic glass. The transducer 1 is so disposed that in its fixed position it is directly coupled to the condenser 5 by a layer 6 of an ultrasonic coupling agent, for example, silicone grease.
On the same side, the housing 2 is connected to a substantially circular support plate 7 by a screwthread provided on the outer wall of the housing.
The support plate 7 has a diameter of about 135 mm and has a continuous projection 8 at a distance of about 7 mm from its periphery. The projection 8 acts as a mounting element for an ultrasonic mirror 9, which is retained by a ring 10 connected to the support plate by screw connection. The ultrasonic mirror 9 is constructed as a concave mirror and has a non-spherical mirror surface which is symmetrical with respect to rotation about one axis. In the present case, the mirror surface has a shape formed from the combination of a conical surface and a spherical surface. The mirror 9 consists of a suitable material which reflects ultrasound, for example, brass. Another ultrasonic mirror 11 is disposed at a distance of about 75 mm from the crystal of the transducer 1 and has substantially the same diameter as the crystal and a spherical surface. It has a cylindrical rearward projection 12 by means of which it is secured in a retaining ring 13 by means of a set-screw 14. The retaining ring 13 is connected to the ring 10 by brackets 15. The mirror 11 also consists of brass, while the other fixing parts and the transducer casing are made, for example, from aluminium.
In operation, a sound pulse emitted by the transducer 1 is focussed by the condenser 5, expanded by the spherical mirror 11 and then re-focused by the mirror 9. The non-spherical shape of the mirror 9 results in a focal line instead of a focal point. The ultrasonic energy reflected by an annular zone of the mirror 9 is focused at a point of the focal line, i.e., an annular aperture of the optical system corresponds to each point of the focal line. This type of focusing in a focal line gives a narrow bunching over the entire length of this focal line and hence the possibility of good lateral resolution over a considerable depth.
ALTERNATE EMBODIMENTS
Numerous other embodiments are possible apart from the embodiment of the invention described. For example, modifications are possible by changing the path of the rays from the ultrasonic transducer to the mirror 9. Another possibility is to make the mirror 9 spherical and the mirror 11 non-spherical, or make both mirrors 11 and 9 non-spherical. The non-spherical mirror may alternatively be replaced by an acoustic lens having a non-spherical refraction surface.
Apart from these modifications of the arrangement shown in FIG. 1, embodiments differing considerably from these are also possible. FIG. 2 shows a hollow cylinder 16 as an ultrasonic mirror with which it is also possible to obtain focusing in a focal line. An ultrasonic transducer 17 is disposed coaxially of the hollow cylinder 16 and advantageously has a diverging lens 18. The ultrasonic rays 19 emitted by the transducer are reflected on the inner wall of the hollow cylinder 16. All the ultrasonic rays reflected from an inner peripheral circle intersect at a point along the cylinder axis.
The annular transducer shown in FIG. 3 represents another possibility of producing a rotation-symmetrical and convergent sonic field. This transducer comprises an annular housing 21 of substantially U-shaped cross-section, the axis of symmetry of the cross-sectional surface being inclined to the ring axis and intersecting the same at a given distance, for example 12 cm. The open side of the U-shaped cross-section faces this point of intersection and hence the ring axis. An annular damping block 24 of epoxy resin/tungsten, which is acoustically insulated from the housing by cork panels 22, is situated in the annular recess of the housing. On the surface of the damping block 24 facing the open side of the housing there are disposed a plurality of (in this case four) flat segments 23 of a piezoelectric material, which together form a ring, and which are covered by a layer 25 of epoxy resin suitable for resistance to water. The layer 25 also provides mechanical protection for the piezoelectric oscillator formed by the segments 23. An electrical lead 26 runs to each of the segments from the back through suitable bores in the housing 21 and in the damping block 24.
The ultrasonic waves emitted by the piezoelectric oscillator form an annular bunch which focuses in a focal line on the ring axis at a certain distance from the ultrasonic transducer. The length of the focal line determines the depth over which good lateral resolution is obtained. The length of the focal line and its distance from the ultrasonic transducer must therefore be so selected that the object to be observed is illuminated over the entire depth. The distance of the focal line from the ultrasonic transducer is determined substantially by the inclination of the piezoelectric oscillator 23 to the ring axis. The length of the focal line is determined particularly by the width of the annular piezoelectric oscillator.
It is advantageous for the ultrasonic transducer unit containing the transmitter transducer to have a wide aperture of, for example more than 6°. The term "aperture" denotes the ratio of the mean ring diameter to the mean distance of the focal line from the ring. As shown in FIG. 3, the annulus diameter of the transducer unit or assembly is greater than the front-to-back cross-sectional dimensions of the assembly itself. | An apparatus for focusing ultrasonic waves in a focal line by an ultrasonic optical system having at least one rotation-symmetrical, non-spherical acoustical reflection surface which together with an ultrasonic transducer element transmits an at least partially convergent ultrasonic field having an annular cross-section. | 0 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of U.S. patent application Ser. No. 12/731,095, filed Mar. 24, 2010, the entire disclosure of which is incorporated herein by reference in its entirety for all purposes.
FIELD OF THE INVENTION
[0002] This invention relates generally to power management in network systems and more specifically to power management of a network device having multiple connections to a network fabric.
BACKGROUND OF THE INVENTION
[0003] Power consumption is always a concern in managing an enterprise network system. A typical enterprise network, such as a storage network, may include a large number of network devices such as servers, switches, and storage devices. A number of those devices may be situated in a confined physical space. For example, multiple blade servers may be stacked in a single rack. During operation, electrical and mechanical components produce heat, which must be displaced to ensure proper functioning of the server components. In blade enclosures, as in most computing systems, heat may be removed with fans or reduced by the use of air conditioning. As servers become more powerful, more electricity is consumed by not only the servers but also the fans and/or the air conditioners needed to keep the servers cool. As such, it is desirable to find ways to reduce the power consumed by each network device without jeopardizing the operations of those devices or affecting their performance.
SUMMARY OF THE INVENTION
[0004] In general, the present invention relates to systems and methods to reduce power consumption of a network device by using virtualization techniques to migrate connectivity to a shared port on the network device.
[0005] Embodiments of the present invention utilize virtualization techniques to perform port migration on a network device. The virtualization techniques make it possible to encapsulate the characteristics of a first physical port and, based on the encapsulated characteristics, create a virtual port on a second physical port to perform the same functions of the first port. As a result, one or more power-consuming physical ports can be migrated to a single physical port. Those power-consuming ports can then be shut off to save power consumption by the device without losing any connectivity to other fabric-connected devices on the network. When it becomes necessary to switch to a powered-down physical port, or when Input/Output (I/O) bandwidth demand increases beyond the capacity of the single physical port, the same encapsulated characteristics can be re-applied to the first ports and those first ports can be reactivated to provide more bandwidth for the host server.
[0006] In one embodiment, the World Wide Port Name (WWPN) and World Wide Node Name (WWNN) of the first physical port are first noted. Subsequently, an N-Port ID Virtualization (NPIV)-based virtual port on the second port is created using the WWPN/WWNN of the first port so that the newly created virtual port can assume the identity of the first port. The virtual port may then be discovered by the host server and log into all the appropriate target storage devices on the network. After the connectivity between the virtual port and the storage devices is reestablished, I/O traffic to the server is resumed and redirected to the virtual port. Because the virtual port has adopted the same WWPN/WWNN as the powered-down first port, the host server would not know that the physical communication channels for some of its communication has been changed, that a virtual port on the second port, instead of the first port, is now being used to connect to target device. As far as the server is concerned, there has been no change in connectivity to the network. As such, the first physical port can be safely shut down without impacting the connectivity of the hosting server.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] FIG. 1 is a block diagram illustrating a conventional Fibre Channel network including a storage device with two dual-port Fibre Channel Host Bus Adapters (HBAs).
[0008] FIGS. 2 a and 2 b illustrate the connections between an HBA and a fabric switch before and after port migration has been performed according to an embodiment of the invention.
[0009] FIG. 3 is a flow chart illustrating the exemplary steps in migrating a physical port to another port using virtualization techniques according to an embodiment of the invention.
[0010] FIG. 4 illustrates a redundant network adapted to utilize the power saving methods disclosed in embodiments of the invention.
[0011] FIG. 5 illustrates an embodiment of a network adapter that may adopt the power saving methods disclosed in embodiments of the invention.
[0012] FIG. 6 illustrates an exemplary host server according to an embodiment of the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0013] In the following description of preferred embodiments, reference is made to the accompanying drawings which form a part hereof, and in which it is shown by way of illustration specific embodiments in which the invention can be practiced. It is to be understood that other embodiments can be used and structural changes can be made without departing from the scope of the embodiments of this invention.
[0014] In general, the present invention relates to systems and methods to reduce power consumption of a network device by using virtualization techniques to migrate connectivity to a shared port on the network device. Although the following embodiments of the invention are described specifically with reference to server-based HBAs, the methods and systems introduced herein can be extended to hardware environments other than those described below. Furthermore, though the embodiments are described for Fibre Channel networks, it should be understood that they can also be adapted for networks using other protocols, such as Fibre Channel over Ethernet (FCoE).
[0015] FIG. 1 illustrates an exemplary Fibre Channel storage network. The Fibre Channel storage network includes a host server 100 , a fabric switch 106 and two storage devices 108 , 110 . The host server 100 may be connected to the storage devices 108 , 110 through the fabric switch 106 . Although only two storage devices 108 , 110 are illustrated, it should be understood that additional storage devices may be a part of the network and connected to the host server 100 . The host server 100 includes two dual-port host bus adapters (HBAs) 102 , 104 . Each of the dual-port HBAs 102 , 104 has two separate physical Fibre Channel ports (not shown) designed to provide two communication channels to the other devices on the network. Other networks may use multiple single-port adapters each with one physical Fibre Channel port in place of a dual-port HBA. Regardless of what type of HBA is used, each port on the HBAs 102 , 104 is identifiable by a unique WWPN and/or a WWNN and may be designed to be independent of one another. In the network illustrated in FIG. 1 , the two dual-port HBAs 102 , 104 may together provide four connections 112 to the fabric switch 106 . Each of these connections may be a full, physical connection that utilizes one of the physical FC ports on the HBAs 102 , 104 and a dedicated optical fiber (or other physical transport means) connecting the HBAs 102 , 104 to the fabric switch 106 .
[0016] The fabric switch 106 may also include multiple ports (not shown) adapted to transmit and receive data from the host server 100 . The fabric switch 106 may be connected to at least one of storage devices 108 , 110 . The fabric switch 106 may effectively determine, by the WWPNs associated with the ports on the host server 100 and the storage devices 108 , 110 , the connections between the host server 100 and each of the storage devices 108 , 110 . Although only one fabric switch 106 is illustrated in FIG. 1 , it should be understood that the connections between the host server 100 and any one of the storage devices 108 , 110 may go through multiple fabric switches. In other networks, the host server may be connected to different storage devices via different fabric switches.
[0017] Because the illustrated host server 100 of FIG. 1 has four separate connections 112 to the fabric switch 106 , power may be continuously consumed by all of the four physical Fibre Channel ports on the two HBAs 102 , 104 of the server 100 when the server is in operation. Similarly, the corresponding ports on the fabric switch 106 also may always be in a powered-on mode. When the devices are turned on, power may be continuously consumed regardless of whether or not any of the communication channels between the host server and the fabric switch 106 are being used to transmit data. That is, not all the bandwidth available from all the channels 112 may be needed all the time. In fact, it is very often the case that some channels between the server 100 and the fabric switch 106 may carry no data at a particular time. Those channels may exist for redundancy/failover purposes. In other words, some of the ports (or adapters) are present merely as backups to other ports (or adapters). In other networks, some of the channels may be present only for peak demand purposes. During off-peak times, far less bandwidth than the full available bandwidth is needed by the applications on the host server 100 . This may be the case at night, when the usage of the network is typically much lower than during the day. Nevertheless, because all the ports in existing network devices are always on even when they are not actually in use for transmitting data, the amount of power consumed by the network during off-peak hours may not be any less than during peak usage.
[0018] Because each HBA 102 , 104 typically has its own power supply, to the extent that the HBA or portions of the HBAs (e.g., the individual Fibre Channel port) can be shut down for a certain period of time when the bandwidth provided by that HBA 102 , 104 is not needed, some power may be saved. Accordingly, it may be beneficial to shut down ports that are not currently being utilized for carrying data to save power and reduce heat generation. However, simply shutting down an adapter or a port on the adapter and dropping the link between that adapter/port and the fabric switch 106 may not be desirable because it may cause the loss of connection to the storage devices connected to the fabric switch 106 . This in turn would cause loss of connection to the storage devices within the host server's operating system, creating a ripple effect that can yield unpredictable results from the perspective of applications running on the host server.
[0019] Embodiments of the present invention utilize virtualization techniques to perform port migration on a network device. The virtualization techniques make it possible to encapsulate the characteristics of a first physical port and, based on the encapsulated characteristics, create a virtual port on a second physical port to perform the same functions of the first port. As a result, one or more power-consuming physical ports can be migrated to a single physical port. Those power-consuming ports can then be shut off to save power consumption by the device without losing any connectivity to other fabric-connected devices on the network. When it becomes necessary to switch to a powered-down physical port, or when Input/Output (I/O) bandwidth demand increases beyond the capacity of the single physical port, the same encapsulated characteristics can be re-applied to the powered-down ports and those powered-down ports can be reactivated to provide more bandwidth for the host server.
[0020] FIGS. 2 a and 2 b illustrate, respectively, one of the HBAs of FIG. 1 before and after port migration having been performed using virtualization techniques. First referring to FIG. 2 a , one of the dual-port HBAs of FIG. 1 is shown in greater detail here. The HBA 102 may include two independent physical Fibre Channel ports A and B 202 , 204 . As illustrated in FIG. 2 , both physical Fibre Channel ports A and B 202 , 204 are in a powered-on mode. Each of the physical ports 202 , 204 has a live connection to the fabric switch 208 , through which the host server (not shown in FIGS. 2 a and 2 b ) housing the HBA is connected to other devices, such as storage devices, on the network. However, as discussed previously, one of the physical ports (e.g., port 204 ) may be a failover for the other port (e.g., port 202 ). Alternatively, the HBA may not require the bandwidth provided by both physical ports 202 , 204 at the same time. Thus, it is desirable to power down one of the physical ports by migrating the failover/unused physical port 204 to the active port.
[0021] In one embodiment of the invention, virtualization techniques may be used to create a virtual port on a physical port 202 (i.e., the second port) to take on the role of another physical port 204 (i.e., the first port) connected to a common fabric. FIG. 2 b illustrates the dual-port HBA 102 of FIG. 2 a having completed a port migration process. As illustrated in FIG. 2 b , the previously active channel between the second Fibre Channel port 204 and the fabric switch 106 has been powered down. Instead, a virtual instance 206 of the second physical port 204 may be created in physical port 202 through a virtualization process, which will be discussed in detail below. The virtual port 206 may share the same WWPN/WWNN of the powered-down physical port 204 and perform the tasks that used to be performed by physical port 204 . Preferably, the virtualization process is performed in a way that the host server housing the HBA 102 is not aware of the migration of the physical port 204 to the virtual port 206 and that the operation of the fabric switch 106 is unaffected by the migration. As far as the operating system (OS) and applications on the server are concerned, there has been no change in network connectivity to the rest of the network. Nevertheless, because one of the physical ports 204 has been turned off, electrical power that is typically required to run that physical port 204 is no longer needed. Even though the remaining physical port 202 , hosting the virtual port 206 , is now responsible for handling all connectivity of the HBA 102 , it does not require additional power to run. As such, the total amount of power consumed by the HBA 102 maybe reduced as a result of this port migration process.
[0022] FIG. 3 illustrates exemplary steps of a method of port migration of a first physical port to a second physical port. Referring to FIG. 3 , the first task is to ensure that the first and second ports are connected to the same fabric switch (step 301 ). This can be done by verifying the Fibre Channel fabric ID of the fabric switch. Next, all input/output traffic through the first port (i.e., the physical port to be migrated) is paused (step 302 ). The duration of the pause is ideally very short (e.g., about a second). After the traffic is cleared, the link between the first port and the fabric switch can be dropped (step 303 ). In other embodiments, other actions to reduce the power consumption of the first port may be additionally or alternatively performed.
[0023] As previously mentioned, to keep the connectivity of the host server intact, a virtual port must be created on the second port to replace the powered-down first port. The connectivity of the virtual port should be verified so that the host server can function seamlessly during and after the port migration process. Without the virtual port being ready to take over the connections from the first port, applications on the host server may encounter serious errors because the host server typically does not tolerate losing connection to remote devices, which may be used to store critical programs and data that the applications on the server need. Preferably, the migrating process should effectively create a transition to the virtual port in such a way that the OS and applications on the host server can function as usual without detecting the transition from the physical port and the virtual port.
[0024] According to this embodiment, the WWPN and WWNN of the first physical port are first noted (step 304 ). Subsequently, an NPIV-based virtual port on the second port is created using the WWPN/WWNN of the first port so that the newly created virtual port can assume the identity of the first port (step 305 ). The virtual port may then be discovered by the host server and log into all the appropriate target storage devices on the network (step 306 ). After the connectivity between the virtual port and the storage devices is reestablished, I/O traffic to the server is resumed and redirected to the virtual port (step 307 ). Because the virtual port has adopted the same WWPN/WWNN as the powered-down first port, the host server would not know that the physical communication channels for some of its communication has been changed, that a virtual port on the second port, instead of the first port, is now being used to connect to target device. As far as the server is concerned, there has been no change in connectivity to the network. As such, the first physical port can be safely shut down without impacting the connectivity of the hosting server. The process can be carried out for other ports on the same HBA or different HBAs of the server.
[0025] Although the migration of one physical port to another physical port is described above, it is to be understood that multiple ports can be migrated to a single second port in the same way as long as the second port has enough bandwidth for network traffic. If all physical ports of one HBA are migrated to one or more physical ports on another HBA, the first HBA can be shut off completely. The more physical ports that can be virtualized on the second port, the more power can be saved by shutting down these physical ports.
[0026] In another embodiment, the port to be migrated can itself be a virtual port. The same virtualization technique can be used to migrate one or more virtual ports on a first physical device (e.g., a first physical port) to a port of a second physical device. After all of the virtual ports of the first physical device are migrated to the second device, the first physical device can be shut off to save power.
[0027] As such, according to embodiments of the invention, a tradeoff may be made between the aggregated bandwidth of the host server and the amount of power that can be saved. The virtualization process discussed in the embodiments can be performed seamlessly, without any significant interruptions to the operation of the host server. In addition, if the host server shuts down one of more of its physical ports, the corresponding ports on the fabric switch can be optionally turned off. That may reduce the power consumption by the fabric switch.
[0028] The existence of the virtual port on the second port allows the first physical port to be shut down as long as there is sufficient network bandwidth to handle communication from and to the server. Whenever the demand for bandwidth increases, the virtual port on the second port can be shut down and first port can be restarted to provide additional bandwidth. Basically, the above-described virtualization process in FIG. 3 can be reversed. Similarly, if the second port encounters an error and has to be shut down, the virtual port can be terminated and the first port can be powered up again to serve as a backup to the second port. According to embodiments of the invention, whenever a physical port is reactivated, the corresponding virtual port may be shut off.
[0029] In another aspect of the invention, different methods can be used to determine when to initiate the above-described port migration process to reduce power consumption. In one embodiment, a time-based algorithm is used where the migration of ports is scheduled at a predetermined time, for example, at midnight when usage of the servers on the network is typically at its lowest level. Knowing that the access rate for I/O operations is much less at that time of the day, the servers may automatically switch the network adapters to a low-power mode by shutting off one or more physical ports on one or more the adapters of the servers using virtualization techniques as described above.
[0030] In another embodiment, the servers may be running in a power saving mode (i.e., using virtual ports for network connections) unless there is a need to initiate failover procedures in response to problems with the active adapter or physical port on which the virtual ports are created. Typical high-availability systems may include multiple hardware components (e.g., HBAs) and network paths that are redundant. That is, some of the network adapters or ports serve as backups to other adapters/ports. FIG. 4 illustrates an example of a redundant system. The redundant system includes four network ports A-D 400 , 402 , 404 , 406 , two fabric switches 408 , 410 , and a storage device 412 . The network ports 400 , 402 , 404 , 406 may be a part of one or more HBAs or other types of network cards. Two of the ports (A and C) 400 , 404 are active I/O ports connected to the storage device 412 through fabric switch 408 . Ports B and D 402 , 406 are failover ports for ports A and C 400 , 404 , respectively. Both ports B and D 402 , 406 are connected to the storage device 412 through a second switch 410 , which serves as a backup to switch 408 .
[0031] As illustrated in FIG. 4 , the redundant network ports 400 , 402 , 404 , 406 and fabric switches 408 , 410 are designed to provide multiple paths to the storage device 412 . For example, if port A 400 fails, its backup port B 402 may be activated and connection to the storage device 412 may be re-established through port B 402 . Similarly, if the connection between active port C 404 and the storage device 412 is interrupted, port D 406 , the backup port for port C 404 , may be powered up and used to access the remote storage device 412 .
[0032] To save power in this type of redundancy setup, one of the failover ports B and D 402 , 406 may be shut down and a virtual port 414 may be created on the remaining failover port (e.g., port B). This virtualization process of the port can be carried out according to the exemplary embodiments described above. The virtual port 414 has the connectivity and assumes the identity of the turned-off port D 406 , and can still serve as a backup port to port C 404 . In this example, port B 402 is essentially the only active backup port for both ports A and C 400 , 404 during normal operation. However, at the command of a failover application, the powered-down physical port D 406 could be re-established to support failover to a separate, redundant physical port (e.g., port B).
[0033] In another embodiment, a prediction-based method can be used to schedule port migration. In this embodiment, the use of physical ports can be controlled by an algorithm designed to predict the I/O load based on past system behavior. In particular, if the I/O load was previously relatively low when the system was in a certain state, port migration may be initiated if the same state occurs again.
[0034] Some conventional application-specific integrated circuits (ASICs) may have mechanisms to shut down portions of its circuit to be able to reduce its overall power consumption. In another aspect of the invention, an ASIC having multiple ports and adapted to perform the power-saving port migration process described above is provided. Any ports or other hardware blocks of the ASIC can be shut off to save power. Given the large number of ASICs that can be found in devices of a conventional network, the potential saving in power consumption can be significant if the ASIC can be programmed to perform the disclosed port migration process.
[0035] In another aspect of the invention, further power savings can be achieved by controlling the hardware associated with the switch ports. Using the data path that exists between the physical port and the fabric switch, commands could be transmitted to the fabric switch to instruct it to shut down one or more physical ports connected to the now-powered-down host based ports. Alternatively, the fabric switch can be instructed to switch to a lower power state (i.e., power saving mode) to reduce power consumption. When the time comes to re-establish the physical connection, a similar power up command could be used.
[0036] Various embodiments of the invention can be implemented in software or firmware of the device or a combination of both. For example, if port migration in a particular device is time-based, the timer may be an application running on the server. The application has to communicate to the kernel space where the driver resides. The device driver is another software entity that controls the operation of the hardware (e.g., an HBA) by instructing the firmware residing in the hardware to carry out the requisite steps of the virtualization process. In this embodiment, the application is the entity that makes the decision regarding when to initiate the port migration process. When the scheduled time arrives, the application may issue a command to the driver and, in response, the driver may issue a command to pause I/O operation in the designated hardware (e.g., one or more Fibre Channel ports) and then create the virtual ports on the still active port(s). I/O operation can be resumed after the virtual port(s) is discovered by the host server. The firmware associated with the hardware (e.g., HBA) may be responsible for shutting down physical ports to conserve power used by the adapter.
[0037] FIG. 5 illustrates another embodiment of an HBA according to embodiments of the invention. As illustrated, the HBA 900 includes one or more processors 902 , a network interface 904 , a host bus interface 908 , and computer readable storage media, such as Random Access Memory (RAM) 906 and non-volatile memory 912 . The various components of the HBA 900 are all connected to a bus 914 in the HBA 900 and adapted to communicate with each other using the bus 914 . The RAM 912 and the non-volatile memory 906 may be used to store firmware of the HBA 900 and other data. In other embodiments, the firmware may be stored on an external computer-readable storage medium such as a disk and loaded into the HBA 900 during operation. The host bus interface 908 connects the HBA 700 to its host via a host bus 910 . The network interface 904 provides a gateway to an external network.
[0038] FIG. 6 illustrates an exemplary host device according to an embodiment of the invention. The host device 1000 includes one or more processors 1002 , a storage device 1004 , a network interface 1010 , RAM 1006 , and non-volatile memory 1008 . The host device 1000 may also include one or more device drivers and one or more HBAs (not shown) as described above in view of FIG. 5 . The processor 1002 may execute instructions stored in computer-readable storage media such as the RAM 1006 and the non-volatile memory 1008 . The storage device 1004 may be a disk capable of storing programs such as firmware for the HBA. The host device is adapted to transmit and receive data from the network using the network interface 1010 .
[0039] Although embodiments of this invention have been fully described with reference to the accompanying drawings, it is to be noted that various changes and modifications will become apparent to those skilled in the art. Such changes and modifications are to be understood as being included within the scope of embodiments of this invention as defined by the appended claims. | A method for managing power consumption by a network device is disclosed. The network device includes first and second ports, each of the first and second ports identified by a unique identifier and adapted to handle separate network traffic. The method includes verifying that the first and the second ports are connected to a common network end node; shutting off a link between the first port and the network end node; obtaining the unique identifier of the first port; creating, on the second port, a virtual port in response to the unique identifier of the first port; discovering the virtual port on the network device; and redirecting traffic formerly routed through the link through the virtual port. | 8 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] This invention relates to the fabrication of magnetic read/write heads that employ TAMR (thermally assisted magnetic recording) to enable writing on magnetic media having high coercivity and high magnetic anisotropy. More particularly, it relates to the use of a plasmon antenna (PA) to transfer the required thermal energy from the read/write head to the media.
[0003] 2. Description of the Related Art
[0004] Magnetic recording at area data densities of between 1 and 10 Tera-bits per in 2 involves the development of new magnetic recording media, new magnetic recording heads and, most importantly, a new magnetic recording scheme that can delay the onset of the so-called “superparamagnetic” effect. This latter effect is the thermal instability of the extremely small regions on which information must be recorded, in order to achieve the required data densities. A way of circumventing this thermal instability is to use magnetic recording media with high magnetic anisotropy and high coercivity that can still be written upon by the increasingly small write heads required for producing the high data density. This way of addressing the problem produces two conflicting requirements:
[0000] 1. The need for a stronger writing field that is necessitated by the highly anisotropic and coercive magnetic media.
2. The need for a smaller write head of sufficient definition to produce the high areal write densities, which write heads, disadvantageously, produce a smaller field gradient and broader field profile.
[0005] Satisfying these requirements simultaneously may be a limiting factor in the further development of the present magnetic recording scheme used in state of the art hard-disk-drives (HDD). If that is the case, further increases in recording area density may not be achievable within those schemes. One way of addressing these conflicting requirements is by the use of assisted recording methodologies, notably thermally assisted magnetic recording, or TAMR.
[0006] The prior art forms of assisted recording methodologies being applied to the elimination of the above problem share a common feature: transferring energy into the magnetic recording system through the use of physical methods that are not directly related to the magnetic field produced by the write head. If an assisted recording scheme can produce a medium-property profile to enable low-field writing localized at the write field area, then even a weak write field can produce high data density recording because of the multiplicative effect of the spatial gradients of both the medium property profile and the write field. These prior art assisted recording schemes either involve deep sub-micron localized heating by an optical beam or ultra-high frequency AC magnetic field generation.
[0007] The heating effect of TAMR works by raising the temperature of a small region of the magnetic medium to essentially its Curie temperature (T C ), at which temperature both its coercivity and anisotropy are significantly reduced and magnetic writing becomes easier to produce within that region.
[0008] In the following, we will address our attention to a particular implementation of TAMR, namely the transfer of electromagnetic energy to a small, sub-micron sized region of a magnetic medium through interaction of the magnetic medium with the near field of an edge plasmon excited by an optical frequency laser. The transferred electromagnetic energy then causes the temperature of the medium to increase locally.
[0009] The edge plasmon is excited in a small conducting plasmon antenna (PA) approximately 200 nm in width that is incorporated within the read/write head structure. The source of optical excitement can be a laser diode, also contained within the read/write head structure, or a laser source that is external to the read/write head structure, either of which directs its beam of optical radiation at the antenna through a means of intermediate transfer such as an optical waveguide (WG). As a result of the WG, the optical mode of the incident radiation couples to a plasmon mode in the PA, whereby the optical energy is converted into plasmon energy, This plasmon energy is then focused by the PA onto the medium, at which point the heating occurs. When the heated spot on the medium is correctly aligned with the magnetic field produced by the write head pole, TAMR is achieved. The following prior arts describe such TAMR implementations in various forms.
[0010] K. Shimazawa et al. (US Publ. Pat. App. US2010/0103553) describes TAMR structures that utilize edge plasmon mode coupling. Shimazawa et al. shows a near-field light generator composed of an electroconductive material such as Au. No magnetic materials are disclosed.
[0011] Rochelle, (U.S. Pat. No. 6,538,617) describes an antenna for sensing magnetic fields that employs a ferrite magnetic core.
[0012] Takagishi et al. (US Publ. Pat. App. 2010/0027161) discloses an antenna having two magnetic layers with a noble metal layer between them.
[0013] Komura et al. (US Publ. Pat. Appl. 2009/0201600) teaches improving plasma generation efficiency by means of a V-shaped groove and a projection facing the deepest part of the groove in a structure formed of non-magnetic materials.
[0014] Y. Zhou et al. (US Appl. # U.S. Ser. No. 12/456,290 (2009) discloses a plasmon antenna with a magnetic core for thermally assisted magnetic recording.
[0015] None of these prior arts address the issues to be dealt with by the present invention, as will now be described in greater detail.
[0016] Referring first to FIG. 1 , there is shown a schematic illustration of an exemplary prior art TAMR structure in an ABS (shown as a dashed line) view and in a side cross-sectional view. The dimensional directions in the ABS view are indicated as x-y coordinates (in the ABS plane), with the x coordinate being a cross-track coordinate in the plane of the medium and the y coordinate being a down-track direction. In the vertical (y-direction) cross-sectional view, the x coordinate would emerge from the plane of the drawing and the z coordinate is in the direction towards the ABS of the head (the “distal” direction).
[0017] The conventional magnetic write head includes a main magnetic pole (MP) ( 1 ), which is shown with a rectangular ABS shape, a writer coil ( 5 ) (three winding cross-sections drawn) for inducing a magnetic field within the pole structure and a return pole ( 3 ). Generally, magnetic flux emerges from the main magnetic pole, passes through the magnetic media and returns through the return pole.
[0018] The optical waveguide (WG) ( 4 ) guides optical frequency electromagnetic radiation ( 6 ) towards the air bearing surface (ABS) of the write head. The ABS end of the write head will also be called its distal end and the ends of all components that are closest to the ABS will be called their distal ends. The plasmon antenna (PA) ( 2 ), which has a triangular shape in the ABS plane, extends distally to the ABS and is adjacent to the MP ( 1 ). The distal end of the waveguide ( 4 ) is not at the ABS, but terminates at a depth, d, away from the ABS. An optical frequency mode ( 6 ) of the electromagnetic radiation couples to the edge plasmon mode ( 7 ) of the PA ( 2 ) and energy from the edge plasmon mode is then transmitted to the media surface where it heats the surface locally at the ABS edge of the PA triangle.
[0019] An advantage of the design illustrated in this figure is that the WG ( 4 ) terminates before reaching the ABS of the write head so that leakage of visible radiation to the ABS is reduced. Meanwhile, the energy from the edge plasmon mode ( 7 ), upon reaching the ABS, can achieve a spatially confined region that is desirable for achieving a high thermal gradient in the magnetic medium. With the long PA body ( 2 ) and large volume of metal composing the PA, heating damage of the PA is also greatly reduced.
[0020] In the prior art cited above, the materials used to form the PA are metals like Ag and Au that are known to be excellent in generating optically driven plasmon modes. However, in the prior art a problem still exists in aligning the optical heating profile within the region of energy transfer at the medium surface, with the magnetic field profile generated by the write head.
[0021] Referring to FIG. 2 , there are shown schematically a typical prior art magnetic field profile ( 8 ) and below it, a heating profile ( 9 ), such as would be produced by the TAMR writer of FIG. 1 at the position of the heating spot (the peak of the profile) on the magnetic medium. The horizontal coordinate axis in both graphs is the y-coordinate of FIG. 1 . The vertical axis is the magnetic field, H z , in the magnetic field profile and the heat intensity, P heat , in the heating profile. Both profiles are localized within a small region of the magnetic medium. For reference purposes, the ABS shape of the PA ( 2 ) and the ABS shape of the MP ( 1 ) (also shown in FIG. 1 ) are drawn below the axes, so the location of the field and heat transfer can be ascertained.
[0022] As can be seen in FIG. 2 , the heating spot is at the far leading edge of the magnetic field profile produced by the MP. Although this location will allow sufficient writing resolution with enough heating, it is not the optimal positioning of the two curves relative to each other. To obtain the full benefit of TAMR, the slope of the heating profile ( 9 ) should be aligned with the encircled regions of maximum slope ( 10 ) or ( 11 ), of the magnetic field profile. In this case, a multiplicative factor of the two maximum gradients is obtained.
[0023] Due to structural limitations, caused, for example, by the thickness and arrangement of the WG and by choice of the PA design, difficulties in alignments during fabrication, etc., optimal alignment of the heating and field profiles cannot be obtained.
[0024] Referring to FIG. 3A , there is shown a schematic illustration of a front view (looking up at the ABS) of a portion of a simplified version of an alternative form of TAMR prior art as disclosed by Zhou et al. (cited above). The figure shows the ABS of the plasmon antenna ( 22 ) and the distal face (recessed from the ABS) of the adjacent optical waveguide ( 23 ). The plasmon antenna ( 22 ) has a core ( 24 ) formed of magnetic material, partially surrounded by a layer ( 27 ) (shown shaded for clarity) of a non-magnetic highly conductive metal (such as Au or Ag). The antenna is formed in the shape of an elongated prism (more clearly illustrated in the following figure), here shown as a prism with an (exemplary) triangular, or approximately triangular cross-section. We shall hereinafter call such an antenna, with its core of magnetic material, an MCA (magnetic core antenna).
[0025] Referring to FIG. 3B , there is shown a schematic perspective view of the same system as in FIG. 3A . The position of the antenna ( 22 ) with its vertex just above a face of the waveguide ( 23 ) promotes coupling of the edge plasmon ( 7 ), which is substantially confined to the vertex region of the conductive coating ( 27 ), to the electromagnetic optical mode ( 6 ) within the waveguide. The magnetic core ( 24 ) of the plasmon antenna serves to channel the magnetic flux of the main writer pole (not shown in this figure) so that it will align optimally with the thermal energy profile produced by the plasmon field within the magnetic medium.
[0026] Referring to FIG. 4 , there is shown a schematic illustration of a side cross-sectional view of a particular arrangement of the type of MCA TAMR head structure already shown in FIG. 3B . In this illustration the main pole ( 21 ) of a magnetic writer has affixed (or adjacently mounted) to it the magnetic core plasmon antenna ( 22 ) (MCA) of the previous invention of FIG. 3B . The MCA ( 22 ) and main pole (MP) ( 21 ) share a common ABS (shown as a dashed line). A waveguide (WG) ( 23 ) is mounted adjacent to the antenna, MCA ( 22 ), and recessed vertically relative to the ABS. A schematic illustration of the ABS face of the MCA is shown encircled with a dashed line, to indicate the magnetic core ( 24 ), such as a core of FeCo or NiFe, partially overcoated with a layer ( 27 ) of Au (shown shaded for emphasis). In this configuration the flat face of the MCA, which is opposite the vertex and not covered by the overcoat ( 27 ), is parallel to the trailing edge of the MP, while the vertex of the MCA, which supports the edge plasmon mode, faces away from the trailing edge of the MP and is immediately adjacent to the WG ( 23 ). The WG is downtrack of the MCA and its distal end is vertically above the ABS. Dashed arrows from WG ( 23 ) to MCA ( 22 ) indicate the coupling of radiation from WG to the MCA. Arrows indicate the magnetic field emanating from both the pole, MP, ( 21 ) and antenna ( 22 ) and plasmon energy being emitted from the antenna as well. Of course the magnetic field from the antenna is emitted by its core ( 24 ), and the plasmon energy is emitted from its overcoat ( 27 ).
[0027] During recording, the magnetic field produced by the MP ( 21 ) magnetizes the core of the MCA ( 24 ) and can even saturate the core if the spacing is small, literally zero spacing being quite appropriate. Thus, the magnetic core of the antenna can be considered a part of the MP structure rather than the MCA structure, in that its role is to direct magnetic flux to the spot on the medium being heated rather than contribute to the heat generating properties of the edge plasmon mode.
[0028] Referring to FIG. 5 , there is shown a graphical simulation of the magnetic field distribution of the pole ( 21 ) of FIG. 4 , with two curve segments showing the distribution in both the presence ( 20 ) (solid line) and absence ( 25 ) (dashed line) of the MCA. In the simulation, the absent MCA actually corresponds to a plasmon antenna of pure Au, with no magnetic core. The horizontal axis of the graph indicates microns of distance downtrack from the center of the pole. The spot on the medium being heated is approximately 0.35 microns downtrack of the pole center. As can be seen, the magnetic field intensity distribution is essentially constant across the width of the pole, which lies between −0.3 and +0.2 microns (labeled MP). In the absence of the MCA (dashed line ( 25 )), the magnetic field intensity decays sharply beyond the lateral dimensions of the pole.
[0029] In the presence of the MCA (solid line ( 20 )), the magnetic field intensity rises (to approximately 10 kOe, compared to the value of approximately 4 kOe in the absence of the MCA) and peaks at approximately the trailing edge of the MCA, then has a sharp gradient at approximately 0.35 microns. However, the actual spot being heated is located at approximately 0.4 microns, which is at or beyond the outer edge of the plasmon generating layer ( 27 ) in FIG. 4 . This indicates that the strongest field and steepest gradient of the magnetic field profile in the presence of the MCA is at the edge of the magnetic core (( 24 ) in FIG. 4 ), while the actual spot being heated is at the edge of the generating layer (( 27 ) in FIG. 4 ) that covers the core. These results indicate that to reduce the distance between the peak field and gradient and the peak point of heating, a thin MCA plasmon generating layer is preferred.
[0030] However, FIG. 6 shows the graphical simulation results of the transmitted power through the edge plasmon mode at various MCA plasmon layer thicknesses. In these simulations, the MCA is assumed to have a uniform core size and plasmon layer thickness along the MCA length. Both Ag alloy and Au films are considered. The power value indicated on the vertical axis of the graph is the percentage of the power transmitted in the MCA plasmon mode relative to that transmitted using a pure Au antenna. The figure indicates that as the plasmon layer thickness decreases, the efficiency of the coupling of the optical energy to the plasmon mode is significantly reduced. Thus, less heating of the medium is expected with thinner plasmon generating layers. Therefore, a trade-off exists between reducing the separation between the position of the magnetic field peak and the heating peak and achieving efficient heating of the recording medium. The prior arts cited above do not address this trade-off or methods of dealing with it advantageously.
SUMMARY OF THE INVENTION
[0031] It is a first object of the present invention to produce a TAMR head structure in which the separation between the application point of maximum magnetic field to a magnetic medium and the point being heated on that same magnetic medium is optimized, without significantly affecting the plasmon mode coupling efficiency to the optical mode in the antenna of the TAMR head structure.
[0032] It is a second object of this invention to minimize the energy loss during the coupling of the plasmon mode in the antenna to the optical mode in the waveguide of the TAMR head structure.
[0033] It is a third object of the present invention to achieve the previous objects without resorting to a significant variation in present fabrication technologies of TAMR head recording structures.
[0034] These objects will be achieved by means of a plasmon antenna design in a TAMR head in which the MCA has a core of magnetic material, such as CoFe or NiFe, overcoated with a plasmon generating layer (PGL) of non-magnetic highly conductive metal, such as Au or Ag, that is formed to a variable thickness and in which the plasmon mode will be generated. Within the coupling length of optical mode to plasmon mode coupling in the PGL, the thickness of the PGL will be made sufficient to impose little loss of coupling efficiency. The PGL thickness then is quickly reduced as the ABS of the TAMR head is approached so that the magnetic core edge of the antenna (( 24 ) in FIG. 4 ) is much closer to the PGL edge (( 27 ) in FIG. 4 ). Thus, as can be seen in the graphical representation of FIG. 5 , the separation between magnetic field peak and heating peak is reduced. Since the thin portion of the PGL only occupies a short portion of the MCA close to the ABS, the total efficiency of the plasmon coupling will be very little affected.
[0035] Referring to schematic FIGS. 7 A, B, C and D there are shown examples of MCAs with variable thickness PGLs. FIG. 7 A shows an example where the MCA is integrated with the magnetic write pole (MP), i.e. the PGL ( 32 ) is formed over an actual extension of the pole itself ( 31 ) which serves as the magnetic core of the MCA. In the figure, an ABS view (b) is shown immediately below a side view (a). As can be seen in (b), the horizontal cross-section of the MP has been shaped to form a triangular prismatic extension ( 34 ) over which the PGL ( 32 ) has been formed. The optical wave guide (WG) ( 33 ) is adjacent to the PGL of the MCA and only partially overlaps it, so the distal end of the WG is not co-planar with the ABS of the MP and MCA. This recession of the distal end of the WG from the ABS of the MCA is preferred, but is not required.
[0036] FIG. 7 C shows a vertical cross-section of the side view of FIG. 7 A, (a), showing how the PGL ( 32 ) (shaded for clarity) varies in thickness towards the ABS end of the structure. The thicker portion is longer than the thinner portion so that there is a sufficient length for efficient coupling of the optical mode and the plasmon mode to occur within the region of overlap between ( 32 ) and ( 33 ).
[0037] FIG. 7 B, (a) and (b) show side and ABS views respectively of an alternative configuration to FIG. 7 A wherein the MCA (( 31 ) and ( 32 )) is physically separated from the MP ( 39 ). The MCA now has a separate magnetic core ( 31 ) and is partially covered by the PGL ( 32 ). The separation ( 38 ) between the core ( 31 ) and the MP ( 39 ) will be filled by a layer of non-conducting, non-magnetic material. Separation is preferably less than 100 nm and the region of separation is preferably filled with an oxide such as Al 2 O 3 or SiO 2 .
[0038] FIG. 7 D, like FIG. 7 C, shows a vertical cross-section of the side view of FIG. 7 B, (a), showing how the PGL ( 32 ) (shaded for clarity) varies in thickness towards the ABS end of the structure. The thicker portion is longer than the thinner portion so that there is a sufficient length for efficient coupling of the optical mode and the plasmon mode to occur.
[0039] FIG. 7 E shows a more detailed schematic view of a vertical cross-section of the side view of the MCA of either of the previous configurations (a) of FIG. 7 A or FIG. 7 B, showing how the PGL ( 32 ) varies in thickness towards the ABS end of the structure. Three exemplary vertical cross-sections in the horizontal plane, ( 50 ), ( 51 ) and ( 52 ) taken at various positions along the MCA are shown, to indicate more precisely how the thickness of the PGL ( 32 ) varies towards the ABS. In the cross-section ( 52 ), closest to the ABS, the thickness ( 34 ) is preferably less than or equal to 60 nm. The thickest portion ( 35 ), shown in cross-section ( 50 ), away from the ABS, should be at least 10 nm thicker than the thinnest portion. The total length ( 37 ) of the MCA that is covered by the PGL is preferably at least twice the length of the portion covered by the thinnest PGL layer ( 36 ).
[0040] It should be noted that during an actual recording process, either of the TAMR heads of FIG. 7 A or FIG. 7 B (or of the remaining embodiments to be described below) can be moving relative to the medium in either the direction MP to MCA to WG, or in the opposite direction of WG to MCA to MP. Such directional choice depends on the actual magnetic field profile and heating profile in the medium, which determines the direction of the movement for achieving the highest possible recording density. Thus, the MCA can be placed on either the trailing edge or the leading edge of the MP in an actual TAMR head. However, in either case the idea of using variable PGL thickness to obtain a higher plasmon coupling efficiency is the same.
[0041] Referring now to FIGS. 8 A, 8 B and 8 C, there is shown the graphical results (shown in FIG. 8C ) of a simulation comparing the plasmon coupling efficiency (vertical axis in FIG. 8C ) to PGL thickness at the ABS, for two exemplary MCA configurations: FIG. 8A , an MCA with uniform PGL thickness (two identical horizontal cross-sections being shown); FIG. 8B (similar to FIG. 7E ) an MCA with tapered PGL thickness (three, different, horizontal cross-sections being shown). The PGL layer is assumed to be a layer of Au and the MCA core is assumed to be FeCo. For both cases FIG. 8A and FIG. 8B the total length ( 37 ) of the MCA is 2 microns. For the uniformly thick PGL of the MCA in FIG. 8A (thicknesses ( 35 )=( 34 )) the thickness is a constant 190 nm.
[0042] For the MCA with variable thickness PGL of FIG. 8B , the length of the thin portion ( 36 ) is 100 nm and the thickness of this portion, ( 34 ) is varied between 20 nm and 200 nm. The length of the variable thickness transition region ( 30 ) is 200 nm. The thickness of the thick region ( 35 ) is 190 nm. The graph of C shows that the tapered PGL has about twice the plasmon coupling (or generation) efficiency of the uniform PGL at an ABS thickness of 20 nm. The trend lines of the graph show that the advantage of the tapered MCA over the uniform MCA is even larger at thinner ABS PGL thicknesses. Such an advantage makes the tapered MCA ideal for reducing the spacing between the magnetic field profile and the heating profile while keeping high enough heating in the medium as a result of the efficient coupling of the optical to plasmon modes.
[0043] Referring now to schematic FIGS. 9 A- 9 G there is shown a sequence of process steps by which the MCA with variable PGL thickness of the previous figures (eg. FIG. 8B ) can be efficiently and advantageously manufactured. It should be apparent to those skilled in the art how these process steps can be applied to the fabrication of the eight embodiments to be described below. In these process steps the MCA is formed on the trailing edge of the MP. In each of the FIGS. 9A-9G , the leftmost figure is an “ABS view” looking up at the fabrication from the ABS, while the rightmost figure is a vertical cross-section taken through the center of the MCA along a plane perpendicular to the ABS plane. The ABS plane is at the rightmost edge of each figure. The steps below indicate the process step that corresponds to each figure.
[0000] (A) A non-magnetic substrate ( 51 ) is provided.
(B) A tapered trench ( 52 ) is formed in the substrate by a photolithographic or etching process.
(C) A first PGL layer ( 53 ) is deposited conformally filling the trench ( 52 ).
(D) A mask ( 54 ) is formed over a portion of the PGL layer extending back from the ABS.
(E) A second layer of PGL ( 55 ) is deposited over the first layer ( 53 ) in the region behind the mask ( 54 ). In the ABS view, the outline of the second layer is shown as a dashed line, although the layer itself is invisible behind the mask.
(F) The mask is removed showing the stepped layers of the PGL, ( 53 ), ( 55 ).
(G) Deposition or electro-plating of magnetic material ( 56 ) directly over both the PGL layers. The deposition ( 56 ) will be the core of the MCA, ( 53 ) and ( 55 ) is the stepped-thickness PGL now covering the core.
BRIEF DESCRIPTION OF THE DRAWINGS
[0044] The objects, features, and advantages of the present invention are understood within the context of the Description of the Preferred Embodiment as set forth below. The Description of the Preferred Embodiment is understood within the context of the accompanying figures, wherein:
[0045] FIG. 1 is a schematic drawing of a prior art TAMR design,
[0046] FIG. 2 is a schematic graphical representation of the magnetic field profile and heating profile of the prior art design of FIG. 1
[0047] FIGS. 3A and 3B are schematic illustrations showing front ( 3 A) and perspective views ( 3 B) of an antenna/waveguide configuration of a prior art design.
[0048] FIG. 4 is a schematic illustration showing the positioning of the plasmon antenna, waveguide and magnetic write pole of the prior art design of FIG. 3B .
[0049] FIG. 5 is a graphical illustration showing the difference in magnetic field and heating profile alignments for the prior art antenna of FIG. 4 .
[0050] FIG. 6 is a graphical result of a simulation showing the relationship between the thickness of plasmon generating layers and the resulting efficiency of coupling between optical and plasmon modes in the layers.
[0051] FIGS. 7 A (a) and (b), 7 B (a) and (b), 7 C, 7 D and 7 E are schematic illustrations showing various configurations of an MCA with the variable thickness PGL of the present invention.
[0052] FIGS. 8A , 8 B and 8 C compare plasmon coupling efficiencies ( 8 C) of a prior art MCA with a uniform PGL ( 8 A) and an MCA of the present invention with a variable thickness PGL of the present invention ( 8 B).
[0053] FIGS. 9A , 9 B, 9 C, 9 D, 9 E, 9 F and 9 G show a schematic sequence of process steps by which an MCA of the present invention is formed.
[0054] FIGS. 10A , 10 B and 10 C are three views of a schematic illustration of a First Embodiment of the present invention.
[0055] FIGS. 11A , 11 B and 11 C are three views a schematic illustration of a Second Embodiment of the present invention.
[0056] FIGS. 12A , 12 B and 12 C are three views of a schematic illustration of a Third Embodiment of the present invention.
[0057] FIGS. 13A , 13 B and 13 C are three views of a schematic illustration of a Fourth Embodiment of the present invention.
[0058] FIGS. 14A , 14 B and 14 C are three views of a schematic illustration of a Fifth Embodiment of the present invention.
[0059] FIGS. 15A , 15 B and 15 C are three views of a schematic illustration of a Sixth Embodiment of the present invention.
[0060] FIGS. 16A , 16 B and 16 C are three views of a schematic illustration of a Seventh Embodiment of the present invention.
[0061] FIGS. 17A , 17 B and 17 C are three views of a schematic illustration of a Eighth Embodiment of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0062] Each of the preferred embodiments of this invention is a TAMR head for producing high density recording on a magnetic medium. The TAMR head incorporates a plasmon antenna formed as a variable thickness plasmon generating layer (PGL) conformally covering at least two sides of a prism-shaped core of magnetic material. In the embodiments to be described below, the prism shaped core has an exemplary horizontal, cross-sectional tapered shape that approximates a triangle. The PGL conformally covers the vertex of the triangle and the two opposite sides that form the vertex. Other shapes of the core are also possible and other conformal coverings are also possible.
[0063] The PGL supports the generation and transmission of a plasmon mode that is produced by efficient coupling at the thickest region of the PGL with an optical mode generated by an adjacent source of optical radiation such as an optical frequency laser and guided to the antenna by a device such as an optical waveguide. By locating this magnetic core antenna (MCA) adjacent to a magnetic write pole (MP), with the thinnest portion of the PGL at the ABS, a magnetic writing field is produced whose peak strength and gradient are superimposed with the near field of the plasmon mode so that the magnetic medium is both heated and written upon at the same point.
[0064] As noted above, the radiative coupling efficiently generates edge plasmon modes within the thickest region of the PGL, with little loss of energy from the optical radiation. As a result, associated electromagnetic near-fields of the plasmon emerge at the thinnest portion of the PGL and impinge on a small surface area of the magnetic medium very near the point at which the write field emerges, generating thermal energy with a spatially dependent profile within that area and causing the temperature of that area to increase. The magnetic pole of the writer produces a magnetic writing field, with a spatially dependent field intensity profile that impinges on a surface area that essentially overlaps optimally with the plasmon field. The spatial alignment of the thermal energy distribution and the magnetic field is such that there is substantial overlap at their regions of maximum gradient. This overlap increases the effectiveness of the magnetic field in changing the local magnetization of the magnetic medium so that magnetic writing on the medium is greatly enhanced and can be confined to extremely small surface areas.
First Embodiment
[0065] Referring to schematic FIGS. 10 A, B and C, there is shown a side view (A), an ABS view (B) and a vertical cross-sectional view (C) of a first embodiment of a TAMR head that has a magnetic write pole (shaped so that it also forms a magnetic core for the plasmon antenna) ( 31 ) over which is formed a PGL of varying thickness ( 32 ). There is also an optical waveguide ( 33 ) adjacent to the plasmon antenna. Thus, the magnetic core of the plasmon antenna is an integral part of the MP and is, in fact, formed from the material of the MP itself. The PGL conformally covers two opposite sides of the core.
[0066] In this embodiment and all other embodiments the ABS cross-sectional shape of the MP has been given an exemplary trapezoidal form, with the magnetic core of the antenna either projecting out from the widest edge of the MP if it is formed as an integral part of the MP (as in this first embodiment), or adjacent to the widest edge of the MP, if it is a separate core. The antenna core has been given an exemplary triangular shape, i.e., it is formed as two planar sides tapering towards a vertex, with the vertex being farthest from the MP. Since the antenna core is a solid prism, its vertex will form a line that is collinear with the MP. The PGL will be formed so that it covers this vertex and the two tapering sides that meet to form the vertex. As can be seen in the ABS view of FIG. 10B , the pole and antenna are symmetric about a center line that passes through the vertex of the PGL. This will also be the case in all succeeding embodiments.
[0067] In the first four embodiments, the vertex of the PGL will remain a fixed distance from the MP, but in embodiments five through eight, the vertex will slope towards the MP in a direction towards the ABS.
[0068] The waveguide is positioned opposite the vertex of the PGL and adjacent to its thickest region for efficient generation of plasmons. During the recording process, the magnetic pole generates a magnetic field to switch the magnetizations of medium grains. The plasmon antenna, combining the core ( 31 ) and the PGL ( 32 ), transmits electromagnetic energy from an edge plasmon mode to the medium at which point the medium is heated to reduce its coercivity and anisotropy. The plasmon mode is, in turn, generated, by optical radiation within the waveguide ( 33 ) that couples to the PGL ( 32 ) of the plasmon antenna. The electromagnetic energy of the plasmon mode produces localized heating of the medium through absorption of electric field energy from the plasmon mode by the medium.
[0069] The thicker portion of the PGL, farthest from the ABS, is comparatively longer than the thinner portion. The thickness of the thin region, beginning at the ABS tip of the MCA, is equal to or less than approximately 60 nm, with its length extending away from the ABS for a distance less than or equal to approximately 500 nm. The thicker end of the PGL, farthest away from the ABS, has a thickness that is preferably at least 10 nm thicker than the thin portion. The total length of the PGL, consisting of a thin region, a thick region and, a transitional region, is preferably at least twice the length of the thin region (i.e., at least 1000 nm). The minimal spacing between the WG ( 33 ) and the vertex of the PGL ( 32 ) is preferably less than 50 nm. The distal end of the WG is preferably recessed from the ABS of the MCA, but this is not a requirement.
Second Embodiment
[0070] Referring now to schematic FIGS. 11 A, B and C, there is shown a second embodiment that is in every respect the same as the first embodiment except that the MP ( 39 ) and the MCA (( 31 and ( 32 )) are separate and disconnected structures. Note that the MP is here labeled ( 39 ) to distinguish it from the separate magnetic core ( 31 ) of the MCA, which in this embodiment has the shape of a triangular prism with its vertex being a straight line that is substantially parallel to the MP. In the following embodiments, when the MP also forms the core of the MCA it will be numbered ( 31 ), when the MP is separate from the core of the MCA (as in this embodiment), the MP will be numbered ( 39 ) and the core of the MCA will be numbered ( 31 ).
[0071] During recording, the magnetic field from the MP ( 39 ) also magnetizes the magnetic core ( 31 ) of the MCA, which produces a magnetic write field in the medium in addition to the field of the MP. Separation between the MP and the MCA is preferably less than 100 nm and the region of separation is preferably filled with a non-conductive, non-magnetic material, preferably an oxide such as Al 2 O 3 or SiO 2
Third Embodiment
[0072] Referring to schematic FIGS. 12 A, B and C, there is shown a schematic side view, an ABS view and a vertical cross-sectional view of a third embodiment of the present invention, in which there is formed a TAMR head that, like the first embodiment, includes an MCA that is a variable thickness PGL ( 32 ) formed directly on a portion of the MP ( 31 ) so that the MCA becomes an integral part of the MP. As in the first embodiment there is a WG ( 33 ) adjacent to the vertex of the PGL and alongside the thickest portion of the PGL for the most efficient coupling of optical and plasmon energies. During the recording process, the magnetic field is generated by the magnetic core ( 31 ) of the MCA and transmitted into the recording medium. The optical mode in the WG ( 33 ) couples to the PGL and generates a plasmon mode that is transmitted along the MCA towards the ABS of the TAMR head. The near field of this plasmon mode impinges on the recording medium and heats it locally. The PGL ( 32 ) is thinner close to the ABS ( 34 ) than farther away from the ABS. The thicker portion of the PGL is longer than the thinner portion so that an efficient coupling between the optical mode and the plasmon mode can occur. The thinnest portion of the PGL may be less than or equal to 60 nm in thickness and it is approximately 500 nm in length. The thicker portion of the PGL is preferably at least 10 nm thicker than the thinnest portion. The total length ( 37 ) of the PGL is preferably at least twice the length ( 36 ) of the thinnest portion. The minimal spacing between the WG structure and the PGL vertex edge is preferably less than 50 nm. The WG preferably terminates above the ABS, but this is not a necessity. A magnetic write shield ( 38 ) is positioned at the same side as the WG relative to the MCA and is located between the distal end of the WG and the ABS. The distance between the PGL edge facing the WG ( 33 ) and the shield ( 38 ) is preferably between approximately 10 nm and 500 nm. The distance between the WG ( 33 ) and the shield ( 38 ) is preferably less than the total length ( 37 ) of the MCA. The thickness of the write shield ( 38 ) at the end facing the MCA is preferably less than or equal to approximately 500 nm. The vertex of the PGL is substantially a straight line. In addition, a thin layer of PGL material, having a thickness of between approximately 10 and 20 nm can be deposited on surface ( 48 ) of shield ( 38 ) facing the vertex of PGL ( 32 ), which helps in reducing the size of the heating spot in the medium.
Fourth Embodiment
[0073] Referring now to schematic FIGS. 13 A, B and C, there is shown a fourth embodiment that is in every respect the same as the third embodiment except that the MP ( 39 ) and the MCA (( 32 ) and ( 31 )) are separate and disconnected structures. During recording, the magnetic field from the MP ( 39 ) also magnetizes the magnetic core ( 31 ) of the MCA, which produces a magnetic write field in the medium in addition to the field of the MP. Separation between the MP and the MCA is preferably less than 100 nm and the region of separation is preferably filled with a non-conductive, non-magnetic material, preferably oxides such as Al 2 O 3 or SiO 2 . In addition, a thin layer of PGL material, having a thickness between approximately 10 and 20 nm, can be deposited on surface ( 48 ) of shield ( 38 ) facing the vertex of PGL ( 32 ), which helps in reducing the size of the heating spot in the medium.
Fifth Embodiment
[0074] Referring now to schematic FIGS. 14 A, B and C, there is shown a fifth embodiment that is in every respect the same as the first embodiment except that the vertex edge is no longer a straight edge parallel to the MP as in the previous embodiments. The vertex edge now has two continuous portions, a first portion that is farthest from the ABS and is parallel to the MP and a second portion of the vertex edge ( 40 ) of the PGL that tapers towards the ABS end of the MP ( 31 ) as shown. It is noted that the tapering of the vertex edge may generally produce a reduction in the dimensions of the ABS cross-sectional shape of the PGL
Sixth Embodiment
[0075] Referring now to schematic FIGS. 15 A, B and C, there is shown a sixth embodiment that is in every respect the same as the second embodiment except that, as in the fifth embodiment, the vertex edge of the PGL is no longer a straight edge entirely parallel to the MP, but there is now a portion that tapers ( 40 ) towards the ABS end of the MP ( 39 ) as shown. It is noted that the tapering of the vertex edge may generally produce a reduction in the dimensions of the ABS cross-sectional shape of the PGL
Seventh Embodiment
[0076] Referring now to schematic FIGS. 16 A, B and C, there is shown a seventh embodiment that is in every respect the same as the third embodiment except that a portion of the vertex edge ( 40 ) of the PGL is not an edge that is parallel to the MP, but is an edge that tapers ( 40 ) towards the MP ( 31 ) in the direction towards the ABS, while the write shield ( 38 ) edge ( 48 ) facing the PGL can, but is not required to, form a slope that is conformal to the tapered portion of the vertex edge ( 40 ) of the PGL. It is noted that the tapering of the vertex edge may generally produce a reduction in the dimensions of the ABS cross-sectional shape of the PGL
[0077] In addition, a thin layer of PGL material, having a thickness between approximately 10 and 20 nm, can be deposited on surface ( 48 ) of shield ( 38 ) facing the vertex of PGL ( 40 ), which helps in reducing the size of the heating spot in the medium.
Eighth Embodiment
[0078] Referring now to schematic FIGS. 17 A, B and C, there is shown an eighth embodiment that is in every respect the same as the fourth embodiment except that the vertex edge ( 40 ) of the PGL, along which the plasmon propagates is not a straight edge parallel to the MP, but is a straight edge that tapers towards the MP ( 39 ) in the direction towards the ABS, while the write shield ( 38 ) edge ( 48 ) facing the PGL can, but is not required to, form a slope that is conformal to the tapered portion of the plasmon carrying edge ( 40 ) of the PGL. It is noted that the tapering of the vertex edge may generally produce a reduction in the dimensions of the ABS cross-sectional shape of the PGL
[0079] Separation between the MP and the MCA is preferably less than 100 nm and the region of separation is preferably filled with a non-conductive, non-magnetic material, preferably oxides such as Al 2 O 3 or SiO 2 . In addition, a thin layer of PGL material, having a thickness between approximately 10 and 20 nm, can be deposited on surface ( 48 ) of shield ( 38 ) facing the vertex of PGL ( 40 ), which helps in reducing the size of the heating spot in the medium.
[0080] As is understood by a person skilled in the art, the preferred embodiments of the present invention are illustrative of the present invention rather than being limiting of the present invention. Revisions and modifications may be made to methods, processes, materials, structures, and dimensions through which is formed and used a TAMR write head with a plasmon antenna having a PGL of varying thickness that provides an efficient coupling between an optical mode and a plasmon mode and optimizes a distance on a magnetic medium between a point of maximum magnetic write field and its gradient and a point of surface heating, while still providing such a TAMR write head, formed and used in accord with the present invention as defined by the appended claims. | A TAMR (Thermal Assisted Magnetic Recording) write head uses the energy of optical-laser generated plasmons in a magnetic core plasmon antenna to locally heat a magnetic recording medium and reduce its coercivity and magnetic anisotropy. To enable the TAMR head to operate most effectively, the maximum gradient and value of the magnetic recording field should be at a point of the magnetic medium that is as close as possible to the point being heated. In addition, the coupling between the optical mode and the plasmon mode should be efficient so that maximum energy is transmitted to the medium. The present invention achieves both these objects by surrounding the magnetic core of a plasmon antenna by a variable thickness plasmon generating layer, whose thinnest and shortest portion is at the ABS end of the TAMR head and whose thickest and longest portion efficiently couples to the optical mode of a waveguide to produce a plasmon. | 6 |
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims the benefit of Korean Application No. 10-2007-0119190, filed on Nov. 21, 2007 in the Korean Intellectual Property Office, the disclosure of which is incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the invention
[0003] The present invention relates to an apparatus and method for detecting malware; and, more particularly, to a malware detection apparatus and method for estimating whether an executable file is malware by analyzing the header of the executable file and detecting the malware.
[0004] This work was supported by the IT R & D program of MIC/IITA [2006-S-042-02, “Development of Signature Generation and Management Technology against Zero-day Attack”].
[0005] 2. Description of the Related Art
[0006] Analyses on recent attacks to communication environments reveal that the types of attacks have changed. In the past, attacks generally generated a great deal of network traffics. However, most of the recent attacks have been made to capture desired information by focusing on specific targets using malware.
[0007] Malware is also known as malicious program, malicious software, or malicious code and they collectively refer to executable codes authored for malicious purposes. Malware can be divided into virus, worm virus, and Trojan horse according to whether it has a self-replication ability and whether there are infection targets.
[0008] Similar to malware, spyware refers to software that sneaks in a computer of somebody and takes important personal information out of the computer. Since spyware has evolved to capture Internet Protocol (IP) address, frequently visited Uniform Resource Locator (URL), and personal identification (ID) and password as well as the name of a user, people concerns about the possibility that spyware might be used maliciously.
[0009] Major symptoms caused by malware include increased network traffic, drop in system performance, file deletion, auto-transmission of email, personal information drain, remote control and so forth and damages increase day by day. Most malicious programs are adopting diverse anti-analysis methods in order to conceal the intention and activity of the malicious programs, even if the malware is detected and analyzed by security specialists.
[0010] Since the symptoms and distribution methods of malware become more complicated and intellectual, existing antivirus programs have limitation in detecting and curing diverse malicious programs.
[0011] Also, most conventional malware detection apparatuses and methods generate signature as the antivirus specialists analyze detected malware and detects the identical malware by using the signature. However, the conventional malware detection apparatuses and methods cannot detect malware if the malware does not have the exactly same signature as the detected malware, and they cannot cope with unknown malware.
SUMMARY OF THE INVENTION
[0012] The present invention relates to technology for determining whether an executable file is malware by analyzing the header of an executable file, e.g., portable executable (PE) file, based on possible characteristics of malware. An embodiment of the present invention is directed to providing a malware detecting apparatus and method that can quickly detect malware and cope with even unknown malware.
[0013] In accordance with an aspect of the present invention, there is provided an apparatus for detecting malware, which includes a header extractor, a file determiner, a header analyzer and a malware determiner. The header extractor extracts a header of an input file, and the file determiner determines whether the input file is an executable file or not. The header analyzer analyzes the extracted header of the file and deciding a probability that the input file is malware based on a determination result of the file determiner. The malware determiner collects determination results of the header analyzer, finally determines whether the input file is malware, and outputs a final determination result.
[0014] In accordance with another aspect of the present invention, there is provided a method for detecting malware, in which a header of an input file is analyzed to determine whether the input file is an executable file, and when the input file is an executable file, it is determined whether the input executable file is malware through a plurality of predetermined conditions by analyzing the header of the input file. When the input executable file is determined as malware, a signal corresponding to presence of malware is outputted.
ADVANTAGEOUS EFFECTS
[0015] The malware detection apparatus and method of the present invention can detect malware using the characteristics acquired through analysis of the executable file header of detected malware. Since the malware detection apparatus and method can quickly detect malware, it can shorten detection time considerably. The malware detection apparatus and method can also detect even unknown malware as well as known malware to thereby estimate and determine presence of malware. Therefore, it is possible to cope with malware in advance, protect a system with a program, and increase security level remarkably.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] FIG. 1 is a block diagram of a malware detection apparatus in accordance with an embodiment of the present invention.
[0017] FIG. 2 illustrates a structure of a header of an executable file in accordance with an embodiment of the present invention.
[0018] FIG. 3 is a flowchart describing a malware detection method in accordance with an embodiment of the present invention.
[0019] FIG. 4 is a flowchart describing a method for determining whether a file is an executable file in a malware detection apparatus in accordance with an embodiment of the present invention.
[0020] FIG. 5 is a flowchart illustrating a method for determining whether a file is malware in a malware detection apparatus in accordance with an embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0021] The advantages, features and aspects of the invention will become apparent from the following description of the embodiments with reference to the accompanying drawings, which is set forth hereinafter.
[0022] Malware adopts diverse anti-analysis schemes to prohibit itself from being analyzed. In this case, portable executable (PE) header of the malware has a different form from that created by using a general compiler through a normal method.
[0023] When the malware employs an anti-analysis scheme, the position or characteristic of the PE header is changed. This causes the PE header to have characteristics that rarely appear in general executable files. The present invention takes advantage of the characteristics and determines whether an executable file is malware or not.
[0024] FIG. 1 is a block diagram of a malware detection apparatus in accordance with an embodiment of the present invention.
[0025] Referring to FIG. 1 , the malware detection apparatus includes a malware detector 100 , a data storage 60 , a controller 50 , an input unit 70 , and an output unit 80 . The malware detection apparatus may further include an interface for connection to another device or a predetermined network communication module.
[0026] The malware detector 100 receives a predetermined file, analyzes the header of the received file, and determines whether the input file is malware based on the analysis result, and outputs the result.
[0027] The controller 50 generates a predetermined message corresponding to the result outputted from the malware detector 100 , and the output unit 80 outputs the determination result.
[0028] The input unit 70 includes a plurality of buttons so that a user can select and input a file to be examined for the probability of being malware among a plurality of files stored in the data storage 60 by manipulating the buttons. The data storage 60 stores a plurality of program data and data produced from the operation of the malware detector 100 . Herein, the data storage 60 includes a volatile memory for temporarily storing an executed program and data produced in the middle of process, a non-volatile memory for storing data, or a memory device for storing a great deal of data.
[0029] The output unit 80 includes at least one among a display for showing text or image, a light emitting device that is turned on or off or flickers in some cases, such as lamp, and a sound output device for outputting predetermined sound effect in order to output the operation state of the malware detection apparatus. The output unit 80 drives at least one among the display, the light emitting device, and the sound output device according to a control command from the controller 50 to output whether the input executable file is malware or not. For example, it may output a message indicating whether the file is malware on the display, flicker the light emitting device, or output a certain beeping sound.
[0030] The malware detector 100 receives a file stored in the data storage 60 or input from outside and determines whether the file is malware according to the manipulation of the input unit 70 . The malware detector 100 checks whether the input file is an executable file of a PE format that can be executed in a Windows operating system. If the header structure of the executable file or a data value included in the header of the executable file satisfies a predetermined condition, it determines the input file as malware. The PE format is applied to all files with extender EXE or DLL.
[0031] The malware detector 100 includes a file determiner 10 , a header extractor 20 , a header analyzer 30 , and a malware determiner 40 .
[0032] The file determiner 10 determines whether the input file is an executable file of a PE format, which is a PE file. The file determiner 10 analyzes the header of the input file and determines whether the input file is an executable file based on whether predetermined data exist at a position designated in the header.
[0033] When the input file is determined to be an executable file in the file determiner 10 , the header extractor 20 additionally extracts a field value of the header used in the header analyzer 30 other than a field value of the header checked out in the file determiner 10 .
[0034] The header analyzer 30 analyzes the executable file and determines the probability that the file is malware by using the headers and field values of the headers extracted in the file determiner 10 and the header extractor 20 . The header analyzer 30 takes advantage of a plurality of field values included in the header related to a section of the executable file, determines whether the respective field values satisfy predetermined conditions, and if there is a section corresponding to each condition, determines that the file is highly likely to be malware. Also, the header analyzer 30 compares a field value of a header related to code with a reference value and determines whether the executable file has a possibility to be malware.
[0035] The malware determiner 40 gives a weight to a result of the header analyzer 30 , collectively takes the weights into consideration, and finally determines whether the executable file is malware or not. Herein, the weight used in the malware determiner 40 may be modified according to security level or security policy of each system. Since the modification can be made by a user of the malware detection apparatus, further description on it will not be provided herein.
[0036] The malware determiner 40 supplies the determination result on whether the input file is malware to the controller 50 , which performs control to have the determination result outputted through the output unit 80 .
[0037] FIG. 2 illustrates a structure of a header of an executable file in accordance with an embodiment of the present invention.
[0038] Referring to FIG. 2 , the header of the executable file includes a first header (IMAGE_DOS_HEADER) and Disk Operating System (DOS) compatible dummy (H 110 ) which are related to code, a PE header (IMAGE_NT_HEADERS) (H 120 ), and a third header (IMAGE_SECTION_HEADER) and array section table (H 130 ) which are related to a section. The executable file further includes other headers, which will not be described herein.
[0039] The header of the executable file includes a region for code and a region for data. When the executable file is actually executed, the regions of the header are loaded onto a memory.
[0040] The PE file starts from the first header (IMAGE_DOS_HEADER) (H 111 ) which has a size of 64 bytes and includes fields such as e_magic and e_lfanew. The value of the first field (e_magic) of the first header (H 111 ) is ‘MZ’(0x5A4D). In other words, the header of the PE file starts with ‘MZ.’ The last field of the first header (H 111 ) is the first field (e_lfanew) includes 4-byte data and it includes start offset of the PE header (H 120 ).
[0041] In short, when the PE file is executed, it is checked whether the PE file starts with ‘MZ’ and the first header is sequentially executed, and then the checking object is jumped to the PE header (H 120 ) at the position where the data of the first field (e_lfanew), which is the last field of the first header (H 111 ).
[0042] Herein, the DOS compatible dummy (H 110 ) following the first header (H 111 ) is a storage for storing error messages to be outputted when Windows program is executed.
[0043] After the first header (H 111 ), the PE header (H 120 ) is executed. The PE header (H 120 ) is a structure of IMAGE_NT_HEADERS, and it includes essential information for a PE loader.
[0044] A header starts with the PE header (H 120 ), and the PE header (H 120 ) includes 4-byte signature and the subsequent second header (H 122 ), which is 20-byte IMAGE_FILE_HEADER. Also, the PE header (H 120 ) further includes 224-byte IMAGE_OPTIONAL_HEADER (H 123 ) and 128-byte data directory array (H 124 ).
[0045] The PE header (H 120 ) includes a PE signature “PE00.” When the system executing the PE file is Windows, the signature of the PE header (H 120 ) should be “PE00.” Otherwise, program is not executed. Accordingly, the malware detection apparatus of the present invention checks whether the signature is “PE00” to see if the PE file is normal.
[0046] Herein, the second header (H 122 ) IMAGE_FILE_HEADER includes information on physical layout and properties of the PE file, and the IMAGE_OPTIONAL_HEADER (H 123 ) takes in charge of logical layout.
[0047] The second header (IMAGE_FILE_HEADER) (H 122 ) includes information on the type of Central Processing Unit (CPU), time taken for creating a PE file, whether a file is of EXE or DLL, and the number of sections. The second header (H 122 ) includes a Machine field, which is a second field, and a NumberOfSections field.
[0048] The Machine field, which is a second field, indicates the type of a system where the file is executed. That is, it indicates the type of CPU. When the value of the Machine field is changed, quick execution of program is interrupted. The NumberOfSections field indicates the number of sections and it is used to forcibly add or delete a section.
[0049] Besides, the second header (H 122 ) includes a TimeDateStamp field, which indicates the date, and time when a file is created, and a PointerToSymbolTable field and a NumberOfSymbols field which are required during debugging.
[0050] The third header (IMAGE_SECTION_HEADER) (H 131 to H 135 ) which is related to section and a section table (H 130 ) includes code on the PE file, data, resources, and other information on the executable file.
[0051] Section is a group of information having attributes such as code/data and read/write. Section includes those having the same attributes and there are diverse attributes.
[0052] A section table divides sections with a reference line. The section table is an array of IMAGE_SECTION_HEADER structure. Each section includes a header and raw data, and the section table includes only the headers of sections. Herein, the section number is the same as the array size.
[0053] The third header (IMAGE_SECTION_HEADER) includes a third field, which is a Characteristic field, indicating whether the extender of the executable file is EXE or DLL, a fourth field, which is a Name field, indicating the name of a section, and a fifth field, which is a SizeOfRawData field, indicating the size of a section.
[0054] Since the header of an executable file is formed as shown in FIG. 2 , the file determiner 10 determines whether a file is an executable file of a PE format based on the field value included in the first header (IMAGE_DOS_HEADER) (H 111 ) and the second header (IMAGE_FILE_HEADER) (H 122 ).
[0055] Herein, the file determiner 10 first checks whether the PE file starts with ‘MZ.’ When the PE file starts with ‘MZ,’ it extracts part of the header of the PE file and checks if there is ‘PE00’ at a predetermined position.
[0056] As described above, since a typical PE file has a first header (IMAGE_DOS_HEADER) starting with a DOS signature ‘MZ,’ if an input file does not start with ‘MZ,’ the file determiner 10 determines that the input file is not PE file.
[0057] Also, when the header of the PE file starts with ‘MZ,’ the file determiner 10 extracts 64 bytes of the header of the PE file and checks the value of the first field (e_lfanew) of the first header (IMAGE_DOS_HEADER). Herein, if there is no ‘PE00’ at a position corresponding to the value of the first field, it determines that the input file is not a PE file.
[0058] Also, when the input file satisfies the two conditions, the file determiner 10 extracts the second header (IMAGE_FILE_HEADER) (H 122 ) and checks the value of the second field (Machine) of the second header (H 122 ), which indicates the type of CPU. When the value of the second field (Machine) is as shown in the following Table 1, the file determiner 10 finally determines that the input file is a PE file.
[0059] If the value of the second field (Machine) is not any one of 0X014C, 0X0200 and 0X8664 as shown in Table 1, the file determiner 10 determines that the input file is not a PE file.
[0000]
TABLE 1
Definition
Value
Meaning
IMAGE_FILE_MACHINE_I386
0x014c
Intel 386 CPU (32bit)
IMAGE_FILE_MACHINE_IA64
0x0200
Intel 386 CPU (64bit)
IMAGE_FILE_MACHINE_AMD64
0x8664
AMD64(K8) CPU
[0060] Herein, the value of the second field (Machine) is about the CPU of a system executing the executable file. In case of a 32-bit Intel CPU, the IMAGE_FILE_MACHINE — 1386 value of the second field is 0X014C. In case of a 64-bit Intel CPU, the IMAGE_FILE_MACHINE_IA64 value of the second field is 0X0200.
[0061] The value of the second field (Machine) used in the file determiner 10 to determine whether an input is a PE file or malware is for limiting the range of determination to systems using CPU. Therefore, the present invention is not limited to it and the values may be added or changed as CPU specification of a system executing a PE file or technology advances.
[0062] The header analyzer 30 determines the probability of a PE file being malware by using the field values shown in the following Table 2 among a plurality of field values of headers extracted by the header extractor 20 . The header extractor 20 extracts the third header (IMAGE_SECTION_HEADER) related to a section and a data region.
[0000]
TABLE 2
Headers
Field Name
Characteristics
IMAGE_SECTION_HEADER
Characteristics
Characteristics
of a section
IMAGE_SECTION_HEADER
SizeOfRawData
Size of a section
IMAGE_SECTION_HEADER
Name
Name of a section
IMAGE_DOS_HEADER
e_lfanew
Position of PE
signature
[0063] The third header (IMAGE_SECTION_HEADER) relates to a section and each field of the third header includes a section-specific value.
[0064] The header analyzer 30 takes advantage of the third field (Characteristics) and checks whether there is a section including both executable attribute and write attribute, whether there is a section including any one between executable attribute and code attribute, and whether there is an executable section in the values of the third field.
[0065] Also, the header analyzer 30 checks whether there is a section including a value that cannot be printed in the fourth field (Name) value of the third header (IMAGE_SECTION_HEADER), and whether the total sum of the values of the fifth field (SizeOfRawDate) is greater than the entire size of the PE file.
[0066] Furthermore, the header analyzer 30 checks whether the first field (e_lfanew) value of the first header (IMAGE_DOS_HEADER) (H 122 ) is smaller than the size of the first header, and whether the first field value of the first header is greater than a predetermined reference.
[0067] A section including both executable attribute and write attribute among the sections included in a third field (Characteristics) value is usually used in malware to change a code region while the PE file is executed. Typical PE files do not have such section. Thus, when there is a section including both executable attribute and write attribute in the third field (Characteristics) value, the header analyzer 30 determines that the PE file is highly likely to be malware.
[0068] Also, the case when there is a section including any one between executable attribute and code attribute in the third field (Characteristics) value and the case whether there is no executable section in the third field (Characteristics) value are the cases that the author of malware arbitrarily changes the PE file to prohibit the malware from being analyzed. In a typical PE file, a section including an executable attribute among sections included in the third field value also includes a code attribute, too. A typical PE file includes at least one executable section. In short, the third field value of a general PE file includes at least one section including both executable attribute and code attribute.
[0069] If there is a section including a value which cannot be printed in the fourth field (Name) value, it is to prohibit a PE file analyzer from easily detecting the start and end of a specific section in malware. In short, it is one of the characteristics of malware for prohibiting a PE file from being analyzed. A general PE file normally generated using a typical compiler does not have such section.
[0070] When the total sum of the fifth field (SizeOfRawDate) values is greater than the entire size of the file, it is to set up the size of a specific section large in malware so as to prohibit the PE file from being analyzed by making a malware detection program spend long time to read the malware.
[0071] Also, the case that the first field (e_lfanew) value of the first header (IMAGE_DOS_HEADER) (H 122 ) is smaller than the size of the first header cannot occur in general PE files. Thus, this is a case manufactured to prohibit malware from being analyzed.
[0072] The case that the first field (e_lfanew) value of the first header (IMAGE_DOS_HEADER) (H 122 ) is greater than a predetermined reference also occurs to prohibit malware from being analyzed. Generally, the PE signature (H 121 ) exists at a position where the IMAGE_DOS_HEADER and DOS compatible dummy end in a PE file.
[0073] The header analyzer 30 checks whether the above 7 conditions are satisfied and when at least one of the 7 conditions is satisfied, it determines that the PE file is highly likely to be malware.
[0074] The malware determiner 40 determines that the PE file is normal, when all the above 7 conditions are not satisfied in the header analyzer 30 . When any one of the 7 conditions is satisfied, it gives a weight to each satisfied condition and determines whether the PE file is malware based on the collective result.
[0075] The operation of the malware detection method will be described herein in accordance with an embodiment of the present invention.
[0076] FIG. 3 is a flowchart describing a malware detection method in accordance with an embodiment of the present invention.
[0077] Referring to FIG. 3 , at step S 210 , a file to be analyzed is selected and input to the malware detection apparatus through manipulation of the input unit 70 . At step S 220 , the file determiner 10 checks whether the input file is a PE file or not by using headers of the input file.
[0078] To determine whether the input file is a PE file or not, the file determiner 10 checks whether the input file starts with a predetermined signature or whether a PE signature indicating that the input file is a PE file is positioned at a predetermined position.
[0079] When the file determiner 10 determines that the input file is a PE file, the header extractor 20 additionally extracts a header and provides the extracted header to the header analyzer 30 at step S 230 . Herein, the header extractor 20 extracts a header to be used in the header analyzer 30 other than a header extracted in the file determiner 10 .
[0080] At step S 240 , the header analyzer 30 analyzes the header of the PE file and checks whether an anti-analysis scheme is applied to the header of the PE file to determine the probability that the PE file is malware.
[0081] At step S 250 , the malware determiner 40 gives a weight to the analysis result of the header analyzer 30 , finally determines whether the input PE file is malware by collectively estimating weights, and outputs a determination result.
[0082] Herein, the controller 50 performs control to output a predetermined message or beeping sound through the output unit 80 based on a determination result of the malware determiner 40 . When the input PE file is malware, at step S 260 , the controller 50 performs control to output a message or beeping sound indicating the presence of malware through the output unit 80 .
[0083] When it is determined that the PE file is normal, at step S 270 , a message or a predetermined sound effect indicating that the PE file is normal is outputted through the output unit 80 .
[0084] FIG. 4 is a flowchart describing a method for determining whether a file is an executable file in a malware detection apparatus in accordance with an embodiment of the present invention.
[0085] Referring to FIG. 4 , the file determiner 10 determines whether an input file is a PE file or not based on field values included in the first header (IMAGE_DOS_HEADER) and the second header (IMAGE_FILE_HEADER).
[0086] Herein, the file determiner 10 extracts the first header (IMAGE_DOS_HEADER) (H 111 ) at step S 310 , analyzes the extracted header, and checks whether the header starts with ‘MZ’ at step S 320 .
[0087] When the first header (IMAGE_DOS_HEADER) (H 111 ) starts with ‘MZ’, that is, when the start of the PE file is ‘MZ’, at step S 330 , the file determiner 10 checks the value of the first field (e_lfanew) and, at step S 340 , checks whether there is a PE signature (PE 00 ) (h 121 ) at a position corresponding to the value of the first field.
[0088] Herein, when the first header does not start with ‘MZ’ and the PE signature is not positioned at the position corresponding to the value of the first field (e_lfanew) but at another position, it determines that the input file is not an executable file of a PE format at step S 400 .
[0089] When the input file starts with ‘MZ’ and the PE signature is positioned at the designated position, at step S 350 , the header extractor 20 additionally extracts a header to be used in the header analyzer 30 . At the step S 350 , the header extractor 20 extracts the second header (IMAGE_FILE_HEADER) and a section header (IMAGE_SECTION_HEADER) from the structure of the PE header.
[0090] At steps S 360 to S 380 , the file determiner 10 compares the value of the second field (Machine) of the second header (IMAGE_FILE_HEADER) for a system specification where the PE file is executed with ‘0X014C’, ‘0X0200’ and ‘0X8664’. Herein, as described above, the second field value has a different value according to a system operating system.
[0091] At step S 390 , when the second field value is matched with at least any one of the codes, the file determiner 10 determines that the input file is an executable file of a PE format. Otherwise, when it is matched with non of the codes, the file determiner 10 determines that the input file is not a PE file at step S 400 .
[0092] FIG. 5 is a flowchart illustrating a method for determining whether a file is malware in a malware detection apparatus in accordance with an embodiment of the present invention.
[0093] Referring to FIG. 5 , when the file determiner 10 determines that the input file is an executable file of a PE format, the header analyzer 30 determines the probability that the executable file is malware.
[0094] At step S 420 , the header analyzer 30 checks whether there is a section including both executable attribute and write attribute by using the value of the third field (Characteristics) of the third header (IMAGE_SECTION_HEADER). At step S 430 , it checks whether there is a section including any one between executable attribute and code attribute. At step S 440 , it checks whether there is no executable section, that is, whether all included sections are not executable.
[0095] Also, the header analyzer 30 checks at step S 450 whether there is a section including a value that cannot be printed based on the value of the fourth field (Name) of the third header (IMAGE_SECTION_HEADER). It checks at step S 460 whether the total sum of the values of the fifth field (SizeOfRawData) is greater than the entire size of the file. In addition, the header analyzer 30 checks at step S 470 whether the value of the first field (e_lfanew) of the first header (IMAGE_DOS_HEADER) (H 111 ) is smaller than the size of the first header (H 111 ) and whether the first field value of the first header is greater than a predetermined reference value.
[0096] Whether the above conditions are satisfied is not decided sequentially in the above-described sequence but the sequence for checking the conditions can be changed.
[0097] The header analyzer 30 decides the probability that the input file is malware by checking the above conditions, outputs the determination result to the malware determiner 40 . The malware determiner 40 give a weight for each decision, and finally determines whether the input file is malware based on collective decision.
[0098] Therefore, the malware detection apparatus and method of the present invention analyzes the headers of an executable file, checks whether predetermined conditions are satisfied, and determines whether the executable file is malware or not to thereby cope with new types of malware.
[0099] While the malware detection apparatus and method of the present invention has been described with respect to certain preferred embodiments, it will be apparent to those skilled in the art that various changes and modifications may be made without departing from the scope of the invention as defined in the following claims. | The present invention relates to an apparatus and method for detecting malware. The malware detection apparatus and method of the present invention determines whether a file is malware or not by analyzing the header of an executable file. Since the malware detection apparatus and method can quickly detect presence of malware, it can shorten detection time considerably. The malware detection apparatus and method can also detect even unknown malware as well as known malware to thereby estimate and determine presence of malware. Therefore, it is possible to cope with malware in advance, protect a system with a program, and increase security level remarkably. | 6 |
[0001] This application is a Continuation of application Ser. No. 10/251,756 filed Sep. 23, 2002, now U.S. Pat. No. 6,714,895 which issued on Mar. 30, 2004, and which is a Divisional of application Ser. No. 09/605,027 filed Jun. 28, 2000, now U.S. Pat. No. 6,456,960 which issued Sep. 24, 2002, and is a Divisional of application Ser. No. 09/501,274 filed Feb. 9, 2000, now U.S. Pat. No. 6,393,381 which issued on May 21, 2002, and is a Divisional of application Ser. No. 08/838,302 filed Apr. 16, 1997, now U.S. Pat. No. 6,119,076.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] This invention generally relates to a unit and method for remotely monitoring and/or controlling an apparatus and specifically to a lamp monitoring and control unit and method for use with street lamps.
[0004] 2. Background of the Related Art
[0005] The first street lamps were used in Europe during the latter half of the seventeenth century. These lamps consisted of lanterns which were attached to cables strung across the street so that the lantern hung over the center of the street. In France, the police were responsible for operating and maintaining these original street lamps while in England contractors were hired for street lamp operation and maintenance. In all instances, the operation and maintenance of street lamps was considered a government function.
[0006] The operation and maintenance of street lamps, or more generally any units which are distributed over a large geographic area, can be divided into two tasks: monitor and control. Monitoring comprises the transmission of information from the distributed unit regarding the unit's status and controlling comprises the reception of information by the distributed unit.
[0007] For the present example in which the distributed units are street lamps, the monitoring function comprises periodic checks of the street lamps to determine if they are functioning properly. The controlling function comprises turning the street lamps on at night and off during the day.
[0008] This monitor and control function of the early street lamps was very labor intensive since each street lamp had to be individually lit (controlled) and watched for any problems (monitored). Because these early street lamps were simply lanterns, there was no centralized mechanism for monitor and control and both of these functions were distributed at each of the street lamps.
[0009] Eventually, the street lamps were moved from the cables hanging over the street to poles which were mounted at the side of the street. Additionally, the primitive lanterns were replaced with oil lamps.
[0010] The oil lamps were a substantial improvement over the original lanterns because they produced a much brighter light. This resulted in illumination of a greater area by each street lamp. Unfortunately, these street lamps still had the same problem as the original lanterns in that there was no centralized monitor and control mechanism to light the street lamps at night and watch for problems.
[0011] In the 1840's, the oil lamps were replaced by gaslights in France. The advent of this new technology began a government centralization of a portion of the control function for street lighting since the gas for the lights was supplied from a central location.
[0012] In the 1880's, the gaslights were replaced with electrical lamps. The electrical power for these street lamps was again provided from a central location. With the advent of electrical street lamps, the government finally had a centralized method for controlling the lamps by controlling the source of electrical power.
[0013] The early electrical street lamps were composed of arc lamps in which the illumination was produced by an arc of electricity flowing between two electrodes.
[0014] Currently, most street lamps still use arc lamps for illumination. The mercury-vapor lamp is the most common form of street lamp in use today. In this type of lamp, the illumination is produced by an arc which takes place in a mercury vapor.
[0015] [0015]FIG. 1 shows the configuration of a typical mercury-vapor lamp. This figure is provided only for demonstration purposes since there are a variety of different types of mercury-vapor lamps.
[0016] The mercury-vapor lamp consists of an arc tube 110 which is filled with argon gas and a small amount of pure mercury. Arc tube 110 is mounted inside a large outer bulb 120 which encloses and protects the arc tube. Additionally, the outer bulb may be coated with phosphors to improve the color of the light emitted and reduce the ultraviolet radiation emitted. Mounting of arc tube 110 inside outer bulb 120 may be accomplished with an arc tube mount support 130 on the top and a stem 140 on the bottom.
[0017] Main electrodes 150 a and 150 b , with opposite polarities, are mechanically sealed at both ends of arc tube 110 . The mercury-vapor lamp requires a sizeable voltage to start the arc between main electrodes 150 a and 150 b.
[0018] The starting of the mercury-vapor lamp is controlled by a starting circuit (not shown in FIG. 1) which is attached between the power source (not shown in FIG. 1) and the lamp. Unfortunately, there is no standard starting circuit for mercury-vapor lamps. After the lamp is started, the lamp current will continue to increase unless the starting circuit provides some means for limiting the current. Typically, the lamp current is limited by a resistor, which severely reduces the efficiency of the circuit, or by a magnetic device, such as a choke or a transformer, called a ballast.
[0019] During the starting operation, electrons move through a starting resistor 160 to a starting electrode 170 and across a short gap between starting electrode 170 and main electrode 150 b of opposite polarity. The electrons cause ionization of some of the Argon gas in the arc tube. The ionized gas diffuses until a main arc develops between the two opposite polarity main electrodes 150 a and 150 b . The heat from the main arc vaporizes the mercury droplets to produce ionized current carriers. As the lamp current increases, the ballast acts to limit the current and reduce the supply voltage to maintain stable operation and extinguish the arc between main electrode 150 b and starting electrode 170 .
[0020] Because of the variety of different types of starter circuits, it is virtually impossible to characterize the current and voltage characteristics of the mercury-vapor lamp. In fact, the mercury-vapor lamp may require minutes of warm-up before light is emitted. Additionally, if power is lost, the lamp must cool and the mercury pressure must decrease before the starting arc can start again.
[0021] The mercury-vapor lamp has become the predominant street lamp with millions of units produced annually. The current installed base of these street lamps is enormous with more than 500,000 street lamps in Los Angeles alone. The mercury-vapor lamp is not the most efficient gaseous discharge lamp, but is preferred for use in street lamps because of its long life, reliable performance, and relatively low cost.
[0022] Although the mercury-vapor lamp has been used as a common example of current street lamps, there is increasing use of other types of lamps such as metal halide and high pressure sodium. All of these types of lamps require a starting circuit which makes it virtually impossible to characterize the current and voltage characteristics of the lamp.
[0023] [0023]FIG. 2 shows a lamp arrangement 201 with a typical lamp sensor unit 210 which is situated between a power source 220 and a lamp assembly 230 . Lamp assembly 230 includes a lamp 240 (such as the mercury-vapor lamp presented in FIG. 1) and a starting circuit 250 .
[0024] Most cities currently use automatic lamp control units to control the street lamps. These lamp control units provide an automatic, but decentralized, control mechanism for turning the street lamps on at night and off during the day.
[0025] A typical street lamp assembly 201 includes a lamp sensor unit 210 which in turn includes a light sensor 260 and a relay 270 as shown in FIG. 2. Lamp sensor unit 210 is electrically coupled between external power source 220 and starting circuit 250 of lamp assembly 230 . There is a hot line 280 a and a neutral line 280 b providing electrical connection between power source 220 and lamp sensor unit 210 . Additionally, there is a switched line 280 c and a neutral line 280 d providing electrical connection between lamp sensor unit 210 and starting circuit 250 of lamp assembly 230 .
[0026] From a physical standpoint, most lamp sensor units 210 use a standard three prong plug, for example a twist lock plug, to connect to the back of lamp assembly 230 . The three prongs couple to hot line 280 a , switched line 280 c , and neutral lines 280 b and 280 d . In other words, the neutral lines 280 b and 280 d are both connected to the same physical prong since they are at the same electrical potential. Some systems also have a ground wire, but no ground wire is shown in FIG. 2 since it is not relevant to the operation of lamp sensor unit 210 .
[0027] Power source 220 may be a standard 115 Volt, 60 Hz source from a power line. Of course, a variety of alternatives are available for power source 220 . In foreign countries, power source 220 may be a 220 Volt, 50 Hz source from a power line. Additionally, power source 220 may be a DC voltage source or, in certain remote regions, it may be a battery which is charged by a solar reflector.
[0028] The operation of lamp sensor unit 210 is fairly simple. At sunset, when the light from the sun decreases below a sunset threshold, the light sensor 260 detects this condition and causes relay 270 to close. Closure of relay 270 results in electrical connection of hot line 280 a and switched line 280 c with power being applied to starting circuit 250 of lamp assembly 230 to ultimately produce light from lamp 240 . At sunrise, when the light from the sun increases above a sunrise threshold, light sensor 260 detects this condition and causes relay 270 to open. Opening of relay 270 eliminates electrical connection between hot line 280 a and switched line 280 c and causes the removal of power from starting circuit 250 which turns lamp 240 off.
[0029] Lamp sensor unit 210 provides an automated, distributed control mechanism to turn lamp assembly 230 on and off. Unfortunately, it provides no mechanism for centralized monitoring of the street lamp to determine if the lamp is functioning properly. This problem is particularly important in regard to the street lamps on major boulevards and highways in large cities. When a street lamp burns out over a highway, it is often not replaced for a long period of time because the maintenance crew will only schedule a replacement lamp when someone calls the city maintenance department and identifies the exact pole location of the bad lamp. Since most automobile drivers will not stop on the highway just to report a bad street lamp, a bad lamp may go unreported indefinitely.
[0030] Additionally, if a lamp is producing light but has a hidden problem, visual monitoring of the lamp will never be able to detect the problem. Some examples of hidden problems relate to current, when the lamp is drawing significantly more current than is normal, or voltage, when the power supply is not supplying the appropriate voltage level to the street lamp.
[0031] Furthermore, the present system of lamp control in which an individual light sensor is located at each street lamp, is a distributed control system which does not allow for centralized control. For example, if the city wanted to turn on all of the street lamps in a certain area at a certain time, this could not be done because of the distributed nature of the present lamp control circuits.
[0032] Because of these limitations, a new type of lamp control unit is needed which allows centralized monitoring and/or control of the street lamps in a geographical area.
[0033] One attempt to produce a centralized control mechanism is a product called the RadioSwitch made by Cetronic. The RadioSwitch is a remotely controlled time switch for installation on the DIN-bar of control units. It is used for remote control of electrical equipment via local or national paging networks. Unfortunately, the RadioSwitch is unable to address most of the problems listed above.
[0034] Since the RadioSwitch is receive only (no transmit capability), it only allows one to remotely control external equipment. Furthermore, since the communication link for the RadioSwitch is via paging networks, it is unable to operate in areas in which paging does not exist (for example, large rural areas in the United States). Additionally, although the RadioSwitch can be used to control street lamps, it does not use the standard three prong interface used by the present lamp control units. Accordingly, installation is difficult because it cannot be used as a plug-in replacement for the current lamp control units.
[0035] Because of these limitations of the available equipment, there exists a need for a new type of lamp control unit which allows centralized monitoring and/or control of the street lamps in a geographical area. More specifically, this new device must be inexpensive, reliable, and easy to install in place of the millions of currently installed lamp control units.
[0036] Although the above discussion has presented street lamps as an example, there is a more general need for a new type of monitoring and control unit which allows centralized monitoring and/or control of units distributed over a large geographical area.
[0037] The above references are incorporated by reference herein where appropriate for appropriate teachings of additional or alternative details, features and/or technical background.
SUMMARY OF THE INVENTION
[0038] The present invention provides a lamp monitoring and control unit and method for use with street lamps which solves the problems described above.
[0039] While the invention is described with respect to use with street lamps, it is more generally applicable to any application requiring centralized monitoring and/or control of units distributed over a large geographical area.
[0040] These and other objects, advantages and features can be accomplished in accordance with the present invention by the provision of a lamp monitoring and control unit comprising: a processing and sensing unit for sensing at least one lamp parameter of an associated lamp, and for processing the at least one lamp parameter to monitor and control the associated lamp by outputting monitoring data and control information; and a transmit unit for transmitting the monitoring data, representing the at least one lamp parameter, from the processing and sensing unit.
[0041] These and other objects, advantages and features can also be achieved in accordance with the invention by a lamp monitoring and control unit comprising: a processing unit for processing at least one lamp parameter and outputting a relay control signal; a light sensor, coupled to the processing unit, for sensing an amount of ambient light, producing a light signal associated with the amount of ambient light, and outputting the light signal to the processing unit; a relay for switching a switched power line to a hot power line based upon the relay control signal from the processing unit; a voltage sensor, coupled to the processing unit, for sensing a switched voltage in the switched power line; a current sensor, coupled to the switched power line, for sensing a switched current in the switched power line; and a transmit unit for transmitting monitoring data, representing the at least one lamp parameter, from the processing unit.
[0042] These and other objects, advantages and features can also be achieved in accordance with the invention by a method for monitoring and controlling a lamp comprising the steps of: sensing at least one lamp parameter of an associated lamp; processing the at least one lamp parameter to produce monitoring data and control information; transmitting the monitoring data; and applying the control information.
[0043] A feature of the present invention is that the lamp monitoring and control unit may be coupled to the associated lamp via a standard three prong plug.
[0044] Another feature of the present invention is that the processing and sensing unit may include a relay for switching the switched power line to the hot power line.
[0045] Another feature of the present invention is that the processing and sensing unit may include a current sensor for sensing a switched current in the switched power line.
[0046] Another feature of the present invention is that the processing and sensing unit may include a voltage sensor for sensing a switched voltage in the switched power line.
[0047] Another feature of the present invention is that the transmit unit may include a transmitter and a modified directional discontinuity ring radiator, and the modified directional discontinuity ring radiator may include a plurality of loops for resonance at a desired frequency range.
[0048] Another feature of the present invention is that in accordance with an embodiment of the method, the step of processing may include providing an initial delay, a current stabilization delay, a relay settle delay, to prevent false triggering.
[0049] Another feature of the present invention is that in accordance with an embodiment of the method, the step of transmitting the monitoring data may include a pseudo-random reporting start time delay, reporting delta time, and frequency. The pseudo-random nature of these values may be based on the serial number of the lamp monitoring and control unit.
[0050] An advantage of the present invention is that it solves the problem of providing centralized monitoring and/or control of the street lamps in a geographical area.
[0051] Another advantage of the present invention is that by using the standard three prong plug of the current street lamps, it is easy to install in place of the millions of currently installed lamp control units.
[0052] An additional advantage of the present invention is that it provides for a new type of monitoring and control unit which allows centralized monitoring and/or control of units distributed over a large geographical area.
[0053] Additional advantages, objects, and features of the invention will be set forth in part in the description which follows and in part will become apparent to those having ordinary skill in the art upon examination of the following or may be learned from practice of the invention. The objects and advantages of the invention may be realized and attained as particularly pointed out in the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0054] The invention will be described in detail with reference to the following drawings in which like reference numerals refer to like elements wherein:
[0055] [0055]FIG. 1 shows the configuration of a typical mercury-vapor lamp.
[0056] [0056]FIG. 2 shows a typical configuration of a lamp arrangement comprising a lamp sensor unit situated between a power source and a lamp assembly.
[0057] [0057]FIG. 3 shows a lamp arrangement, according to one embodiment of the invention, comprising a lamp monitoring and control unit situated between a power source and a lamp assembly.
[0058] [0058]FIG. 4 shows a lamp monitoring and control unit, according to another embodiment of the invention, including a processing and sensing unit, a Tx unit, and an Rx unit.
[0059] [0059]FIG. 5 shows a lamp monitoring and control unit, according to another embodiment of the invention, including a processing and sensing unit, a Tx unit, an Rx unit, and a light sensor.
[0060] [0060]FIG. 6 shows a lamp monitoring and control unit, according to another embodiment of the invention, including a processing and sensing unit, a Tx unit, and a light sensor.
[0061] [0061]FIG. 7 shows a lamp monitoring and control unit, according to another embodiment of the invention, including a microprocessing unit, an A/D unit, a current sensing unit, a voltage sensing unit, a relay, a Tx unit, and a light sensor.
[0062] [0062]FIG. 8 shows an example frequency channel plan for a lamp monitoring and control unit, according to another embodiment of the invention.
[0063] [0063]FIG. 9 shows a typical directional discontinuity ring radiator (DDRR) antenna.
[0064] [0064]FIG. 10 shows a modified DDRR antenna, according to another embodiment of the invention.
[0065] FIGS. 11 A-E show methods for one implementation of logic for a lamp monitoring and control unit, according to another embodiment of the invention.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0066] The preferred embodiments of a lamp monitoring and control unit (LMCU) and method, which allows centralized monitoring and/or control of street lamps, will now be described with reference to the accompanying figures. While the invention is described with reference to an LMCU, the invention is not limited to this application and can be used in any application which requires a monitoring and control unit for centralized monitoring and/or control of devices distributed over a large geographical area. Additionally, the term street lamp in this disclosure is used in a general sense to describe any type of street lamp, area lamp, or outdoor lamp.
[0067] [0067]FIG. 3 shows a lamp arrangement 301 which includes lamp monitoring and control unit 310 , according to one embodiment of the invention. Lamp monitoring and control unit 310 is situated between a power source 220 and a lamp assembly 230 . Lamp assembly 230 includes a lamp 240 and a starting circuit 250 .
[0068] Power source 220 may be a standard 115 volt, 60 Hz source supplied by a power line. It is well known to those skilled in the art that a variety of alternatives are available for power source 220 . In foreign countries, power source 220 may be a 220 volt, 50 Hz source from a power line. Additionally, power source 220 may be a DC voltage source or, in certain remote regions, it may be a battery which is charged by a solar reflector.
[0069] Recall that lamp sensor unit 210 included a light sensor 260 and a relay 270 which is used to control lamp assembly 230 by automatically switching the hot power 280 a to a switched power line 280 c depending on the amount of ambient light received by light sensor 260 .
[0070] On the other hand, lamp monitoring and control unit 310 provides several functions including a monitoring function which is not provided by lamp sensor unit 210 . Lamp monitoring and control unit 310 is electrically located between the external power supply 220 and starting circuit 250 of lamp assembly 230 . From an electrical standpoint, there is a hot 280 a with a neutral 280 b electrical connection between power supply 220 and lamp monitoring and control unit 310 . Additionally, there is a switched 280 c and a neutral 280 d electrical connection between lamp monitoring and control unit 310 and starting circuit 250 of lamp assembly 230 .
[0071] From a physical standpoint, lamp monitoring and control unit 310 may use a standard three-prong plug to connect to the back of lamp assembly 230 . The three prongs in the standard three-prong plug represent hot 280 a , switched 280 c , and neutral 280 b and 280 d . In other words, the neutral lines 280 b and 280 d are both connected to the same physical prong and share the same electrical potential.
[0072] Although use of a three-prong plug is recommended because of the substantial number of street lamps using this type of standard plug, it is well known to those skilled in the art that a variety of additional types of electrical connection may be used for the present invention. For example, a standard power terminal block or AMP power connector may be used.
[0073] [0073]FIG. 4 shows lamp monitoring and control unit 310 , according to another embodiment of the invention. Lamp monitoring and control unit 310 includes a processing and sensing unit 412 , a transmit (TX) unit 414 , and an optional receive (RX) unit 416 . Processing and sensing unit 412 is electrically connected to hot 280 a , switched 280 c , and neutral 280 b and 280 d electrical connections. Furthermore, processing and sensing unit 412 is connected to TX unit 414 and RX unit 416 . In a standard application, TX unit 414 may be used to transmit monitoring data and RX unit 416 may be used to receive control information. For applications in which external control information is not required, RX unit 416 may be deleted from lamp monitoring and control unit 310 .
[0074] [0074]FIG. 5 shows a lamp monitoring and control unit 310 , according to another embodiment of the invention, with a configuration similar to that shown in FIG. 4. Here, however, lamp monitoring and control unit 310 of FIG. 5 further includes a light sensor 518 , analogous to light sensor 216 of FIG. 2, which allows for some degree of local control. Light sensor 518 is coupled to processing and sensing unit 412 to provide information regarding the level of ambient light. Accordingly, processing and sensing unit 412 may receive control information either locally from light sensor 518 or remotely from RX unit 416 .
[0075] [0075]FIG. 6 shows another configuration for lamp monitoring control unit 310 , according to another embodiment of the invention, but without RX unit 416 . This embodiment of lamp monitoring and control unit 310 can be used in applications in which only local control information, for example from light sensor 518 , is to be passed to processing and sensing unit 412 . In other words, remote monitoring data may be received via TX unit 414 and local control information may be generated via light sensor 518 .
[0076] [0076]FIG. 7 shows a more detailed implementation of lamp monitoring and control unit 310 of FIG. 6, according to one embodiment of the invention.
[0077] [0077]FIG. 7 shows one embodiment of a lamp monitoring and control unit 310 with a three-prong plug 720 to provide hot 280 a , neutral 280 b and 280 d , and switched 280 c electrical connections. The hot 280 a and neutral 280 b and 280 d electrical connections are connected to an optional switching power supply 710 in applications in which AC power is input and DC power is required to power the circuit components of lamp monitoring and control unit 310 .
[0078] Light sensor 518 includes a photosensor 518 a and associated light sensor circuitry 518 b . TX unit 414 includes a radio modem transmitter 414 a and a built-in antenna 414 b . Processing and sensing unit 412 includes microprocessor circuitry 412 a , a relay 412 b , current and voltage sensing circuitry 412 c , and an analog-to-digital converter 412 d.
[0079] Microprocessor circuitry 412 a includes any standard microprocessor/microcontroller such as the Intel 8751 or Motorola 68HC16. Additionally, in applications in which cost is an issue, microprocessor circuitry 412 a may comprise a small, low cost processor with built-in memory such as the Microchip PIC 8 bit microcontroller. Furthermore, microprocessor circuitry 412 a may be implemented by using a PAL, EPLD, FPGA, or ASIC device.
[0080] Microprocessor circuitry 412 a receives and processes input signals and outputs control signals. For example, microprocessor circuitry 412 a receives a light sensing signal from light sensor 518 . This light sensing signal may either be a threshold indication signal, that is, providing a digital signal, or some form of analog signal.
[0081] Based upon the value of the light sensing signal, microprocessor circuitry 412 a may alternatively or additionally execute software to output a relay control signal to a relay 412 a which switches switched power line 280 c to hot power line 280 a.
[0082] Microprocessor circuitry 412 a may also interface to other sensing circuitry. For example, the lamp monitoring and control unit 310 may include current and voltage sensing circuitry 412 c which senses the voltage of the switched power line 280 c and also senses the current flowing through the switched power line 280 c . The voltage sensing operation may produce a voltage ON signal which is sent from the current and voltage sensing circuitry 412 c to microprocessor circuitry 412 a . This voltage ON signal can be of a threshold indication, that is, some form of digital signal, or it can be an analog signal.
[0083] Current and voltage sensing circuitry 412 c can also output a current level signal indicative of the amount of current flowing through switched power line 280 c . The current level signal can interface directly to microprocessor circuitry 412 a or, alternatively, it can be coupled to microprocessing circuitry 412 a through an analog-to-digital converter 412 b . Microprocessor circuitry 412 a can produce a CLOCK signal which is sent to analog-to-digital converter 412 d and which is used to allow A/D data to pass from analog-to-digital converter 412 d to microprocessor circuitry 412 a.
[0084] Microprocessor circuitry 412 a can also be coupled to radio modem transmitter 414 a to allow monitoring data to be sent from lamp monitoring control unit 310 .
[0085] The configuration shown in FIG. 7 is intended as an illustration of one way in which the present invention can be implemented. For example, analog-to-digital converter 412 b may be combined into microprocessor circuitry 412 a for some applications. Furthermore, the memory for microprocessor circuitry 412 a may either be internal to the microprocessor circuitry or contained as an external EPROM, EEPROM, Flash RAM, dynamic RAM, or static RAM. Current and voltage sensor circuitry 412 c may either be combined in one unit with shared components or separated into two separate units. Furthermore, the current sensing portion of current and voltage sensing circuitry 412 c may include a current sensing transformer 413 and associated circuitry as shown in FIG. 7 or may be configured using different circuitry which also senses current.
[0086] The frequencies to be used by the TX unit 414 are selected by microprocessor circuitry 412 a . There are a variety of ways that these frequencies can be organized and used, examples of which will be discussed below.
[0087] [0087]FIG. 8 shows an example of a frequency channel plan for lamp monitoring and control unit 310 , according to one embodiment of the invention. In this example table, interactive video and data service (IVDS) radio frequencies in the range of 218-219 MHz are shown. The IVDS channels in FIG. 8 are divided into two groups, Group A and Group B, with each group having nineteen channels spaced at 25 KHz steps. The first channel of the group A frequencies is located at 218.025 MHz and the first channel of the group B frequencies is located at 218.525 MHz.
[0088] The mapping between channel numbers and frequencies can either be performed in microprocessor circuitry 412 a or TX unit 414 . In other words the data signal sent to TX unit 414 from microprocessor circuitry 412 a may either consist of channel numbers or frequency data. To transmit at these frequencies, TX unit 414 must have an associated antenna 414 b.
[0089] [0089]FIG. 9 shows a typical directional discontinuity ring radiator (DDRR) antenna 900 . DDRR antenna 900 is well known to those skilled in the art, and detailed description of the operation and use of this antenna can be found in the American Radio Relay League (ARRL) Handbook, the appropriate sections of which are incorporated by reference. The problem with using DDRR antenna 900 in applications such as lamp monitoring and control unit 310 is that the antenna dimension for resonance in certain frequency ranges, such as the IVDS frequency range, is too large.
[0090] [0090]FIG. 10 shows a modified DDRR antenna 1000 , according to a further embodiment of the invention. Modified DDRR antenna 1000 is mounted on a PC board 1010 and includes a metal shield 1020 , a coil segment 1060 , a looped wire coil 1040 , a first variable capacitor C 1 , and a second variable capacitor C 2 . Additionally, a plastic assembly (not shown) may be included in modified DDRR antenna 1000 to hold looped wire coil 1040 in place.
[0091] The RF energy to be radiated is fed into an RF feed point 1050 and travels through wire segment 1060 through a hole 1030 in metal shield 1020 to variable capacitor C 2 . Variable capacitor C 2 is used to match the input impedance of modified DDRR antenna 1000 to 50 ohms. Looped wire coil 1040 is looped several times, as opposed to typical DDRR antenna 900 which only has one loop. Looped wire coil 1040 may be coupled to wire segment 1060 , or both looped wire coil 1040 and wire segment 1060 may be part of a continuous piece of wire, as shown. The end of wire coil 1040 is coupled to capacitor C 1 which tunes modified DDRR antenna 1000 for resonance at the desired frequency.
[0092] Modified DDRR antenna 1000 has multiple loops in wire coil 1040 which allow the antenna to resonate at particular frequencies. For example, if typical DDRR antenna 900 with approximately a 5″ diameter is modified to include three to six loops, then the diameter can be decreased to less than 4″ and still resonate in the IVDS frequency range. In other words, if typical DDRR antenna 900 has a 4″ diameter, it will have poor resonance in the IVDS frequency range. In contrast, if modified DDRR antenna 1000 has a 4″ diameter, it will have excellent resonance in the IVDS frequency range. Accordingly, modified DDRR antenna 1000 provides for an efficient transformation of input RF energy for radiation as an E-M field because of its improved resonance at the desired frequencies and an impedance match (such as 50 ohms) to the input RF source. The exact number of additional loops and spacing for modified DDRR antenna 1000 depends on the frequency range selected.
[0093] Furthermore, if lamp monitoring and control unit 310 includes RX unit 416 , as shown in FIG. 4, modified DDRR antenna 1000 can be shared by TX unit 414 and RX unit 416 . Alternatively, RX unit 416 and TX unit 414 may use separate antennas.
[0094] FIGS. 11 A-E show methods for implementation of logic for lamp monitoring and control unit 310 , according to a further embodiment of the invention. These methods may be implemented in a variety of ways, including software in microprocessor circuitry 412 a or customized logic chips.
[0095] [0095]FIG. 11A shows one method for energizing and de-energizing a street lamp and transmitting associated monitoring data. The method of FIG. 11A shows a single transmission for each control event. The method begins with a start block 1100 and proceeds to step 1110 which involves checking AC and Daylight Status. The Check AC and Daylight Status step 1110 is used to check for conditions where the AC power and/or the Daylight Status have changed. If a change does occur, the method proceeds to the step 1120 which is a decision block based on the change.
[0096] If a change occurred, step 1120 proceeds to a Debounce Delay step 1122 which involves inserting a Debounce Delay. For example, the Debounce Delay may be 0.5 seconds. After Debounce Delay step 1122 , the method leads back to Check AC and Daylight Status step 1110 .
[0097] If no change occurred, step 1120 proceeds to step 1130 which is a decision block to determine whether the lamp should be energized. If the lamp should be energized, then the method proceeds to step 1132 which turns the lamp on. After step 1132 when the lamp is turned on, the method proceeds to step 1134 which involves Current Stabilization Delay to allow the current in the street lamp to stabilize. The amount of delay for current stabilization depends upon the type of lamp used. However, for a typical vapor lamp a ten minute stabilization delay is appropriate. After step 1134 , the method leads back to step 1110 which checks AC and Daylight Status.
[0098] Returning to step 1130 , if the lamp is not to be energized, then the method proceeds to step 1140 which is a decision block to check to deenergize the lamp. If the lamp is to be deenergized, the method proceeds to step 1142 which involves turning the Lamp Off After the lamp is turned off, the method proceeds to step 1144 in which the relay is allowed a Settle Delay time. The Settle Delay time is dependent upon the particular relay used and may be, for example, set to 0.5 seconds. After step 1144 , the method returns to step 1110 to check the AC and Daylight Status.
[0099] Returning to step 1140 , if the lamp is not to be deenergized, the method proceeds to step 1150 in which an error bit is set, if required and proceeds to step 1160 in which an A/D is read. For example, the A/D may be the analog-to-digital converter 412 d for reading the current level as shown in FIG. 7.
[0100] The method then proceeds from step 1160 to step 1170 which checks to see if a transmit is required. If no transmit is required, the method proceeds to step 1172 in which a Scan Delay is executed. The Scan Delay depends upon the circuitry used and, for example, may be 0.5 seconds. After step 1172 , the method returns to step 1110 which checks AC and Daylight Status.
[0101] Returning to step 1170 , if a transmit is required, then the method proceeds to step 1180 which performs a transmit operation. After the transmit operation of step 1180 is completed, the method then returns to step 1110 which checks AC and Daylight Status.
[0102] [0102]FIG. 11B is analogous to FIG. 11A with one modification. This modification occurs after step 1120 . If a change has occurred, rather than simply executing step 1122 , the Debounce Delay, the method performs a further step 1124 which involves checking whether daylight has occurred. If daylight has not occurred, then the method proceeds to step 1126 which executes an Initial Delay. This initial delay may be, for example, 0.5 seconds. After step 1126 , the method proceeds to step 1122 and follows the same method as shown in FIG. 11A.
[0103] Returning to step 1124 which involves checking whether daylight has occurred, if daylight has occurred, the method proceeds to step 1128 which executes an Initial Delay. The Initial Delay associated with step 1128 should be a significantly larger value than the Initial Delay associated with step 1126 . For example, an Initial Delay of 45 seconds may be used. The Initial Delay of step 1128 is used to prevent a false triggering which deenergizes the lamp. In actual practice, this extended delay can become very important because if the lamp is inadvertently deenergized too soon, it requires a substantial amount of time to reenergize the lamp (for example, ten minutes). After step 1128 , the method proceeds to step 1122 which executes a Debounce Delay and then returns to step 1110 as shown in FIGS. 11A and 11B.
[0104] [0104]FIG. 11C shows a method for transmitting monitoring data multiple times in a lamp monitoring and control unit, according to a further embodiment of the invention. This method is particularly important in applications in which lamp monitoring and control unit 310 does not have a RX unit 416 for receiving acknowledgements of transmissions.
[0105] The method begins with a transmit start block 1182 and proceeds to step 1184 which involves initializing a count value, i.e. setting the count value to zero. Step 1184 proceeds to step 1186 which involves setting a variable x to a value associated with a serial number of lamp monitoring and control unit 310 . For example, variable x may be set to 50 times the lowest nibble of the serial number.
[0106] Step 1186 proceeds to step 1188 which involves waiting a reporting start time delay associated with the value x. The reporting start time is the amount of delay time before the first transmission. For example, this delay time may be set to x seconds where x is an integer between 1 and 32,000 or more. This example range for x is particularly useful in the street lamp application since it distributes the packet reporting start times over more than eight hours, approximately the time from sunset to sunrise.
[0107] Step 1188 proceeds to step 1190 in which a variable y representing a channel number is set. For example, y may be set to the integer value of RTC/12.8, where RTC represents a real time clock counting from 0-255 as fast as possible. The RTC may be included in microprocessing circuitry 412 a.
[0108] Step 1190 proceeds to step 1192 in which a packet is transmitted on channel y. Step 1192 proceeds to step 1194 in which the count value is incremented. Step 1194 proceeds to step 1196 which is a decision block to determine if the count value equals an upper limit N.
[0109] If the count is not equal to N, step 1196 returns to step 1188 and waits another delay time associated with variable x. This delay time is the reporting delta time since it represents the time difference between two consecutive reporting events.
[0110] If the count is equal to N, step 1196 proceeds to step 1198 which is an end block. The value for N must be determined based on the specific application. Increasing the value of N decreases the probability of a unsuccessful transmission since the same data is being sent multiple times and the probability of all of the packets being lost decreases as N increases. However, increasing the value of N increases the amount of traffic which may become an issue in a lamp monitoring and control system with a plurality of lamp monitoring and control units.
[0111] [0111]FIG. 11D shows a method for transmitting monitoring data multiple times in a monitoring and control unit according to a another embodiment of the invention.
[0112] The method begins with a transmit start block 1110 ′ and proceeds to step 1112 ′ which involves initializing a count value, i.e., setting the count value to 1. The method proceeds from step 1112 ′ to step 1114 ′ which involves randomizing the reporting start time delay. The reporting start time delay is the amount of time delay required before the transmission of the first data packet. A variety of methods can be used for this randomization process such as selecting a pseudo-random value or basing the randomization on the serial number of monitoring and control unit 510 .
[0113] The method proceeds from step 1114 ′ to step 1116 ′ which involves checking to see if the count equals 1. If the count is equal to 1, then the method proceeds to step 1120 ′ which involves setting a reporting delta time equal to the reporting start time delay. If the count is not equal to 1, the method proceeds to step 1118 ′ which involves randomizing the reporting delta time. The reporting delta time is the difference in time between each reporting event. A variety of methods can be used for randomizing the reporting delta time including selecting a pseudo-random value or selecting a random number based upon the serial number of the monitoring and control unit 510 .
[0114] After either step 1118 ′ or step 1120 ′, the method proceeds to step 1122 ′ which involves randomizing a transmit channel number. The transmit channel number is a number indicative of the frequency used for transmitting the monitoring data. There are a variety of methods for randomizing the transmit channel number such as selecting a pseudo-random number or selecting a random number based upon the serial number of the monitoring and control unit 510 .
[0115] The method proceeds from step 1122 ′ to step 1124 ′ which involves waiting the reporting delta time. It is important to note that the reporting delta time is the time which was selected during the randomization process of step 1118 ′ or the reporting start time delay selected in step 1114 ′, if the count equals 1. The use of separate randomization steps 1114 ′ and 1118 ′ is important because it allows the use of different randomization functions for the reporting start time delay and the reporting delta time, respectively.
[0116] After step 1124 ′ the method proceeds to step 1126 ′ which involves transmitting a packet on the transmit channel selected in step 1122 ′.
[0117] The method proceeds from step 1126 ′ to step 1128 ′ which involves incrementing the counter for the number of packet transmissions.
[0118] The method proceeds from step 1128 ′ to step 1130 ′ in which the count is compared with a value N which represents the maximum number of transmissions for each packet. If the count is less than or equal to N, then the method proceeds from step 1130 ′ back to step 1118 ′ which involves randomizing the reporting delta time for the next transmission. If the count is greater than N, then the method proceeds from step 1130 ′ to the end block 1132 ′ for the transmission method.
[0119] In other words, the method will continue transmission of the same packet of data N times, with randomization of the reporting start time delay, randomization of the reporting delta times between each reporting event, and randomization of the transmit channel number for each packet. These multiple randomizations help stagger the packets in the frequency and time domain to reduce the probability of collisions of packets from different monitoring and control units.
[0120] [0120]FIG. 11E shows a further method for transmitting monitoring data multiple times from a monitoring and control unit 510 , according to another embodiment of the invention.
[0121] The method begins with a transmit start block 1140 ′ and proceeds to step 1142 ′ which involves initializing a count value, i.e., setting the count value to 1. The method proceeds from step 1142 ′ to step 1144 ′ which involves reading an indicator, such as a group jumper, to determine which group of frequencies to use, Group A or B. Examples of Group A and Group B channel numbers and frequencies can be found in FIG. 8.
[0122] Step 1144 ′ proceeds to step 1146 ′ which makes a decision based upon whether Group A or B is being used. If Group A is being used, step 1146 ′ proceeds to step 1148 ′ which involves setting a base channel to the appropriate frequency for Group A. If Group B is to be used, step 1146 ′ proceeds to step 1150 ′ which involves setting the base channel frequency to a frequency for Group B.
[0123] After either Step 1148 ′ or step 1150 ′, the method proceeds to step 1152 ′ which involves randomizing a reporting start time delay. For example, the randomization can be achieved by multiplying the lowest nibble of the serial number of monitoring and control unit 510 by 50 and using the resulting value, x, as the number of milliseconds for the reporting start time delay.
[0124] The method proceeds from step 1152 ′ to step 1154 ′ which involves waiting x number of seconds as determined in step 1152 ′.
[0125] The method proceeds from step 1154 ′ to step 1156 ′ which involves setting a value z=0, where the value z represents an offset from the base channel number set in step 1148 ′ or 1150 ′. Step 1156 ′ proceeds to step 1158 ′ which determines whether the count equals 1. If the count equals 1, the method proceeds from step 1158 ′ to step 1172 ′ which involves transmitting the packet on a channel determined from the base channel frequency selected in either step 1148 ′ or step 1150 ′ plus the channel frequency offset selected in step 1156 ′.
[0126] If the count is not equal to 1, then the method proceeds from step 1158 ′ to step 1160 ′ which involves determining whether the count is equal to N, where N represents the maximum number of packet transmissions. If the count is equal to N, then the method proceeds from step 1160 ′ to step 1172 ′ which involves transmitting the packet on a channel determined from the base channel frequency selected in either step 1148 ′ or step 1150 ′ plus the channel number offset selected in step 1156 ′.
[0127] If the count is not equal to N, indicating that the count is a value between 1 and N, then the method proceeds from step 1160 ′ to step 1162 ′ which involves reading a real time counter (RTC) which may be located in processing and sensing unit 412 .
[0128] The method proceeds from step 1162 ′ to step 1164 ′ which involves comparing the RTC value against a maximum value, for example, a maximum value of 152. If the RTC value is greater than or equal to the maximum value, then the method proceeds from step 1164 ′ to step 1166 ′ which involves waiting x seconds and returning to step 1162 ′.
[0129] If the value of the RTC is less than the maximum value, then the method proceeds from step 1164 ′ to step 1168 ′ which involves setting a value y equal to a value indicative of the channel number offset. For example, y can be set to an integer of the real time counter value divided by 8, so that Y value would range from 0 to 18.
[0130] The method proceeds from step 1168 ′ to step 1170 ′ which involves computing a frequency offset value z from the channel number offset value y. For example, if a 25 KHz channel is being used, then z is equal to y times 25 KHz.
[0131] The method then proceeds from step 1170 ′ to step 1172 ′ which involves transmitting the packet on a channel determined from the base channel frequency selected in either step 1148 ′ or step 1150 ′ plus the channel frequency offset computed in step 1170 ′.
[0132] The method proceeds from step 1172 ′ to step 1174 ′ which involves incrementing the count value. The method proceeds from step 1174 ′ to step 1176 ′ which involves comparing the count value to a value N+1 which is related to the maximum number of transmissions for each packet. If the count is not equal to N+1, the method proceeds from step 1176 ′ back to step 1154 ′ which involves waiting x number of milliseconds. If the count is equal to N+1, the method proceeds from step 1176 ′ to the end block 1178 ′.
[0133] The method shown in FIG. 11E is similar to that shown in FIG. 11D, but differs in that it requires the first and the Nth transmission to occur at the base frequency rather than a randomly selected frequency.
[0134] Although the above figures show numerous embodiments of the invention, it is well known to those skilled in the art that numerous modifications can be implemented.
[0135] For example, FIG. 4 shows a light monitoring and control unit 310 in which there is no light sensor but rather an RX unit 416 for receiving control information. Light monitoring and control unit 310 may be used in an environment in which a centralized control system is preferred. For example, instead of having a decentralized light sensor at every location, light monitoring and control unit 310 of FIG. 4 allows for a centralized control mechanism. For example, RX unit 416 could receive centralized energize/deenergize signals which are sent to all of the street lamp assemblies in a particular geographic region.
[0136] As another alternative, if lamp monitoring and control unit 310 of FIG. 4 contains no RX unit 416 , the control functionality can be built directly in the processing and sensing unit 412 . For example, processing and sensing unit 412 may contain a table with a listing of sunrise and sunset times for a yearly cycle. The sunrise and sunset times could be used to energize and deenergize the lamp without the need for either RX unit 416 or light sensor 518 .
[0137] The foregoing embodiments are merely exemplary and are not to be construed as limiting the present invention. The present teaching can be readily applied to other types of apparatuses. The description of the present invention is intended to be illustrative, and not to limit the scope of the claims. Many alternatives, modifications, and variations will be apparent to those skilled in the art. | A unit and method for remotely monitoring and/or controlling an apparatus and specifically for remotely monitoring and/or controlling street lamps. The lamp monitoring and control unit comprises a processing and sensing unit for sensing at least one lamp parameter of an associated lamp, and for processing the lamp parameter to monitor and control the associated lamp by outputting monitoring data and control information, and a transmit unit for transmitting the monitoring data, representing the at least one lamp parameter, from the processing and sensing unit. The method for monitoring and controlling a lamp comprises the steps of: sensing at least one lamp parameter of an associated lamp; processing the at least one lamp parameter to produce monitoring data and control information; transmitting the monitoring data; and applying the control information. | 7 |
BACKGROUND OF THE INVENTION
The present invention relates to a storage compartment for a container, especially in a motor vehicle.
More particularly it relates to a storage compartment which is intended in particular for mounting on an inner side of a side wall of the container, while the container can be housed, for example beneath a central armrest in the motor vehicle. The storage compartment is intended, for example, for the storage of small items in a larger container.
Such storage compartments are known in the art. The known storage compartments have a disadvantage that they require a substantial space in a larger container.
SUMMARY OF THE INVENTION
Accordingly, it is an object of present invention to provide a storage compartment for a container, especially in a motor vehicle, which is designed so that it can be housed with a minimal use of space in the larger container.
In keeping with these objects and with others which will become apparent hereinafter, one feature of present invention resides, briefly stated, in a storage compartment which has a bottom pivotable by a first hinged joint out of an substantially horizontal position into a substantially vertical position; a wall pivotably mounted by a second hinged joint on said bottom and pivotable out of a position lying flat against said bottom into a position standing away from said bottom; a driving mechanism which, as said bottom is pivoted out of the substantially vertical position into the substantially horizontal position, pivots said wall out of said position lying flat against said bottom into said position standing away from said bottom, and vice versa.
The storage compartment according to the invention is pivotable onto the inner side of the side wall of the container, on which the storage compartment is mounted, so that the storage compartment occupies only little space when not in use. For that purpose, the storage compartment according to the invention has a bottom that is pivotable by means of a hinged joint out of an approximately horizontal position standing away from the side wall into the container, into an approximately vertical position lying flat against the inner side of the side wall of the container. When not in use, the bottom is pivoted against the side wall of the container, so that the entire volume of the container is available as a storage space.
In accordance with the present invention one wall of the storage compartment is pivotally mounted on the bottom of the storage compartment, and is pivotable out of position standing away from the bottom into a position lying flat against the bottom. When the storage compartment is not in use, the wall is pivoted to rest on the bottom and the bottom is pivoted into its approximately vertically upright position.
Furthermore, the storage compartment according to the invention has a driving mechanism (gear mechanism) which positively co-ordinates the pivoting movements of the wall and bottom of the storage compartment with one another, so that, as the bottom is pivoted from the approximately vertical position into the approximately horizontal position, the wall of the storage compartment pivots out of the position lying flat against the bottom into the position standing away from the bottom. If the bottom is pivoted out of the approximately horizontal into the approximately vertical position, the driving mechanism pivots the wall out of the position standing away from the bottom into the position lying flat against the bottom. The invention has the advantage that it offers an opportunity for a container to be divided up and enables small items to be stored tidily in a larger container, wherein, when not in use, the storage compartment according to the invention can be housed with a minimum use of space against the inner side of a side wall of the container.
In accordance with one embodiment of the invention, the driving mechanism comprises a cam mechanism. In a development thereof, the cam mechanism has a fixed guideway in a plane perpendicular to a pivot axis of the bottom. The guideway runs in an arc about the pivot axis of the bottom at a changing distance therefrom. The wall of the storage compartment has a guide element, for example, a laterally projecting guide pin, which engages in the guideway. By virtue of the cam mechanism, an angular position of the wall relative to the bottom of the storage compartment is dependent on the pivoted angle of the bottom, and the pivoting movement of the wall is necessarily derived from the pivoting movement of the bottom, so that the wall stands away from the bottom when the latter takes up its approximately horizontal position, and so that the wall lies flat against the bottom when the latter takes up its approximately vertical position.
In a preferred embodiment of the invention, the bottom of the storage compartment has an overload protection means, which supports the bottom in the approximately horizontal position. If the storage compartment is overloaded, for example, because a heavy object is placed on the storage compartment, the overload protection means gives way, so that the bottom is able to fold away downwards. Damage to the storage compartment is consequently avoided.
In another preferred embodiment, the bottom of the storage compartment is pressed by a spring mechanism into the approximately horizontal position and the wall is passed into the position standing away from the bottom. When not in use, the bottom is held by a releasable holding arrangement in the approximately vertical position. The releasable holding arrangement can comprise, for example, a snap-action projection, which is pressed away resiliently to the side when the bottom is pressed out of the approximately vertical position towards the horizontal position. After overcoming the holding arrangement, the bottom pivots under spring action into its approximately vertical position. Push-push or cardioid locking mechanisms known per se can also be used as releasable holding arrangement.
The novel features which are considered as characteristic for the present invention are set forth in particular in the appended claims. The invention itself, however, both as to its construction and its method of operation, together with additional objects and advantages thereof, will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective exploded view of a storage compartment according to the invention;
FIG. 2 shows a cross-section through the storage compartment of FIG. 1;
FIG. 3 shows a cross-section as shown in FIG. 2 when the storage compartment is not in use;
FIG. 4 shows a cross-section as shown in FIG. 2 with the storage compartment overloaded, and
FIG. 5 shows a longitudinal section through the storage compartment of FIG. 1 .
DESCRIPTION OF PREFERRED EMBODIMENTS
A storage compartment 10 according to the invention shown in exploded view in FIG. 1 comprises essentially a base member 12 , a bottom 14 and a wall 16 , which are manufactured from plastics material as injection-moulded parts. The base member 12 has a longitudinal wall 18 , from the two ends of which project end walls 20 . The bottom 14 is pivotable by means of a hinged joint through 90° out of a vertical position parallel to the base plate 12 into a horizontal position standing away from the base plate 12 at right angles. In its horizontal position, the bottom 14 is located at the lower edges of the end walls 20 . The hinged joint is formed by two pins 22 , which are inserted through holes 24 in the end walls 20 of the base part 12 into holes 26 of the bottom 14 . The two pins 22 are arranged close to the longitudinal wall 18 and just above the lower edges of the end walls 20 ; they define a swivel axis of the bottom 14 parallel to the longitudinal wall 18 . Helical torsion springs 28 are placed on the pins 22 , the spring being supported, as is apparent from FIGS. 2 to 4 , on the base part 12 and pressing the bottom 14 into the horizontal position.
The bottom 14 has laterally projecting ribs 30 , which, in the vertical position of the bottom, co-operate with snap-action projections 32 on the inner side facing one another of the end walls 20 and form a releasable holding arrangement 30 . In the horizontal position of the bottom 14 , the ribs 30 lie on supporting ledges 34 (compare FIG. 5 ), which are likewise arranged on the inner sides of the end walls 20 and together with the ribs 30 form an overload protection means 30 , 34 of the storage compartment 10 .
The wall 16 is pivotally connected to the bottom 14 and can be pivoted through 90° out of a position lying flat against the bottom 14 into a position standing away from the bottom. For the pivotal connection, the bottom 14 and the wall 16 have a hinged joint, which is formed by two pins 36 , which are pushed through holes 38 in lugs on end faces of the wall 16 into holes 40 in the bottom 14 . A helical torsion spring 42 is placed on the pins 36 . The helical torsion spring 42 is supported on the bottom 14 and presses the wall 16 into the position standing away from the bottom 14 .
The storage compartment 10 according to the invention can be inserted in a box-shaped container 44 , which has in one side wall an aperture 46 for receiving the longitudinal wall 18 of the base part 12 of the storage compartment 10 .
On the inner sides of the end walls 20 there are provided guideways 48 , which are in the form of grooves and run in an arc (not necessarily a circular arc) around the holes 24 that define the pivot axis of the bottom 14 . The spacing of the guideways 48 from the holes 24 changes: the guideways 48 could be regarded as portions of spirals that start near the holes 24 and run spirally away from the holes 24 over an angular portion of less than 180°. Spaced from the holes 38 in its lugs, the wall 16 has laterally projecting pegs 50 , which form the guide elements and engage in the guideways 48 . The fixed guideways 48 and the pegs 50 form a cam mechanism 48 , 50 for the wall 16 pivotally connected to the bottom 14 .
The function of the storage compartment 10 according to the invention is explained below with reference to FIGS. 2 and 3. FIG. 2 shows the storage compartment 10 in a position of use inserted in the container 44 . The longitudinal wall 18 on the base member 12 of the storage compartment 10 is mounted on the inside of a side wall 52 of the container 44 . The bottom 14 stands at right angles and horizontally away from the side walls 52 of the container 44 into the inner space of the container 44 . The bottom 14 lies with its lateral ribs 30 on the supporting ledges 34 of the end wall 20 of the storage compartment 10 , the helical torsion springs 28 pressing the bottom 14 into engagement with the supporting ledges 34 . The wall 16 pivotally connected to the bottom 14 stands perpendicularly upwards away from the bottom 14 . It is pressed into this position by the helical torsion springs 42 and held in this position by the pegs 50 , which engage in the guideways 48 .
If the storage compartment 10 is not needed, it can be brought into the non-functional position shown in FIG. 3 . To that end, the bottom 14 is pressed against the force of the helical torsion spring 28 upwards into the vertical position illustrated in FIG. 3 . In the vertical position, between the bottom 14 and the longitudinal wall 18 there is a gap, in which the wall 16 lies. On pivoting the bottom 14 upwards, the wall 16 , the pegs 50 of which slide in the guideways 48 , is pivoted out of its position standing perpendicularly away from the bottom 14 into a position lying flat against the bottom 14 between the bottom 14 and the longitudinal wall 18 . The guideways 48 and the pegs 50 form a cam mechanism 48 , 50 , which constrains the wall 16 to the pivot into contact with the bottom 14 as the bottom 14 is pivoted upwards. If the bottom 14 is pivoted back in the horizontal a position, the guideways 48 and the pegs 50 constrain the wall 16 to pivot into the position standing perpendicularly upwards away from the bottom 14 .
In its position pivoted vertically upwards, the bottom 14 is held against the spring force of the helical torsion springs 28 by its lateral ribs 30 , which snap in against the snap-action projections 32 of the end walls 20 . To bring it into its functional position, the bottom 14 is pressed away from the longitudinal wall 18 , the ribs 30 undergoing resilient deformation to overcome the snap-action projections 32 and the bottom 14 subsequently being pivoted by gravitational force and by the torsion spring elements 28 into the horizontal position. The ribs 30 of the bottom 14 and the snap-action projections 32 of the end walls 20 form a releasable holding arrangement 30 , 32 , which holds the bottom 14 in the vertical position against the force of the helical torsion spring 28 .
If the wall 16 or the bottom 14 of the storage compartment 10 is overloaded in the functional position, for example, because a heavy object is placed thereon, the ribs 30 of the bottom 14 undergo resilient deformation to overcome the supporting ledges 34 of the end walls 20 , and the bottom 14 , together with the wall 16 , pivots beyond the horizontal position downwards, as shown in FIG. 4 . The ribs 30 of the bottom 14 , together with the supporting ledges 34 of the end walls 20 , form an overload protection means, which enables the bottom 14 to fold away downwards together with the wall 16 when overloaded. After being overloaded, the bottom 14 is pressed upwards, until its ribs 30 have overcome the supporting ledges 34 and the storage compartment 10 is ready for use again.
It will be understood that each of the elements described above, or two or more together, may also find a useful application in other types of constructions differing from the types described above.
While the invention has been illustrated and described as embodied in STORAGE COMPARTMENT FOR A CONTAINER, ESPECIALLY IN A MOTOR VEHICLE, it is not intended to be limited to the details shown, since various modifications and structural changes may be made without departing in any way from the spirit of the present invention.
Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can, by applying current knowledge, readily adapt it for various applications without omitting features that, from the standpoint of prior art, fairly constitute essential characteristics of the generic or specific aspects of this invention.
What is claimed as new and desired to be protected by Letters Patent is set forth in the appended claims: | A storage compartment has a bottom pivotable by a first hinged joint out of a substantially horizontal position into a substantially vertical position. A wall is pivotably mounted by a second hinged joint on the bottom and pivotable out of a position lying flat against said bottom into a position standing away from the bottom. A driving mechanism pivots the wall out of the position lying flat against the bottom into the position standing away from the bottom, and vice versa, as the bottom is pivoted out of the substantially vertical position into the substantially horizontal position. | 1 |
BACKGROUND OF THE INVENTION
The present invention relates to the processing of a substrate in the manufacture of integrated circuits. More particularly, the present invention relates to methods and apparatus for determining an endpoint for a plasma etching process in a plasma processing chamber during the processing of semiconductor substrates.
Substrates, e.g., wafers or glass panels, are widely used in the production of electronic devices. By depositing layers of selected materials and etching those layers in accordance with predefined patterns, integrated circuits and flat panel displays may be formed out of wafers and glass panels respectively. Although wafers, and in particular silicon wafers, are mentioned throughout this disclosure to simplify discussion, it should be borne in mind that the invention disclosed herein applies to any kind of substrate, including wafers made out of other materials (e.g., GaAs) as well as glass panels.
Silicon wafers are typically manufactured using plasma processing chambers to perform plasma etching processes during the manufacture of the silicon wafer. These plasma-enhanced etching processes are well known to those skilled in the art. An important aspect of the etching process is properly determining the point at which the plasma etching process is complete. This point at which the etching process is complete is referred to as the endpoint for the etching process. If the etching process proceeds for too long, over etching occurs which may damage the integrated circuit. On the other hand, stopping the etching process too early may result in an incomplete etch which may prevent the proper formation of features in the integrated circuit required to produce a good integrated circuit. As the size or critical dimension of integrated circuits is reduced below the sub micron level, the proper determination of the endpoint of the etching process becomes more and more difficult.
In the past, the endpoint for a particular etching process has been determined by test etching a number of test wafers in order to determine the length of time required for the etching process to etch through the desired layers of the wafer using a specific regime of pressure, flow rates, and flow ratios of etchants. Once this length of time was determined, it was used to determine the endpoint of the etching process. However, because of variations in the thickness of various layers from wafer to wafer and because of variations in the etching rate, this approach of using a predetermined length of time to control the etching process is not very reliable, especially in the case of wafers designed with small critical dimensions.
More recently, optical emission detectors and optical signal analysis have been used to determine the endpoint of certain etching processes. FIG. 1 illustrates a plasma processing system 100 including this type of an optical emission detecting arrangement. Plasma processing system 100 includes a plasma processing chamber 102. System 100 has a gas fine 104 connected to a shower head 106 in chamber 102 for releasing etchant gases into the chamber. A chuck 108 is used to support a silicon wafer 110 during the processing of the wafer. In order to monitor the wafer during the processing of the wafer, chamber 102 also includes a window 112. Window 112 allows light, indicated by arrow 114, that is produced by the reactions within chamber 102 to be detected by optical sensors outside of the chamber.
As illustrated in FIG. 1, system 100 includes an optical sensor 116 for measuring the intensity of light 114 emitted through window 112 during the etching process. Optical sensor 116 produces an electrical signal indicated by arrow 118 which represents the intensity of light 114. A computer 120 uses a detection algorithm and electrical signal 118 to determine the endpoint for the etching process. Computer 120 generates an endpoint signal indicated by arrow 122 which is sent to a chamber controller 124. Controller 124 uses endpoint signal 122 to stop the etching process and moves on to the next step in the processing of the wafer.
As is known in the art, system 100 also includes energy sources for striking a plasma within chamber 102 and an arrangement for exhausting the byproducts of the etching process. In the embodiment shown, RF sources 126 and 128 are used to respectively energize shower head 106 and chuck 108 in order to strike a plasma within chamber 102. Also, an exhaust port 130 is used to exhaust the byproducts of the etching process as the byproducts are produced. Typically, a turbo pump or other such device is used to draw any byproducts of the etching process from chamber 102.
During the etching process, etch species and reactants in the processing chamber emit light when their excited electrons change energy states. Each species produces a unique wavelength of light, and the intensity of each wavelength of light emitted from the plasma is related to the concentration of that species within the plasma. As a wafer is being etched, a reaction equilibrium is generally sustained within the plasma until the layer which is being etched starts to clear or be filly removed. At this point, the increase in the concentration of the etchant species and the decrease in the concentration of the reaction product species causes the light intensities associated with these species to increase or decrease. By measuring the light emission intensity change associated with the chemical species in the plasma, an endpoint for the etching process can be determined.
Two types of endpoint determination methods are currently in use. The first and most common is the threshold method of determining the endpoint. In this method, a sensor is used to detect the intensity of a certain wavelength of light which is produced by one of the reactants of the etching process. Generally, when the intensity of the wavelength of light crosses a predetermined threshold, the computer signals that the endpoint has been reached. In the second method, the shape of a curve representing the changes in the intensity of a particular wavelength of light which is produced by one of the reactants is used to determine the endpoint. In this method, the computer monitors the electrical signal provided by the optical sensor and compares the shape of the signal over time to a predetermined shape. Once a match is found, the computer signals the endpoint for the etching process
Optical emission detection arrangements such as the ones described above have several drawbacks which may make them costly and unreliable. In a first example of the drawbacks of this approach, the window in the chamber will typically become cloudy after a relatively short period of time. This is caused by deposits of polymers or other reaction products within the plasma on the inner surface of the window. Because the optical emission method uses the intensity of light emitted from the chamber to determine the endpoint of the process, a cloudy window can substantially reduce the intensity of the signal causing inaccurate readings. These inaccurate readings can cause the system to indicate the endpoint at the wrong time resulting in damaged and unusable wafers. In many cases, this clouding of the window will occur in as few as 2000 minutes of operation of the chamber. This means that the system must be shut down and cleaned regularly substantially reducing the throughput for the system and increasing the costs of producing the wafers.
As a second drawback, as the critical dimensions of the devices being produced on the wafer become smaller and smaller, the optical signals or light produced by the reactants becomes weaker and weaker. This makes it more and more difficult to discriminate between the background noise (e.g. light from other sources) and the light produced by the reactant which is being used to detect the endpoint. This may result in not detecting the proper endpoint and may significantly reduce the yield for a given etching process. Because of the very high cost of producing wafers with complex integrated circuits, this reduced yield can be very costly.
As another disadvantage, using either the threshold or the shape method of detecting the endpoint requires a large number of wafers to be tested in order to establish an acceptable range of conditions within which the endpoint may be determined. This is because there is always some variation from wafer to wafer or in the flow rates and reaction rates of the etching process. In order to deal with these variations, a large number of test wafers are etched in order to establish a statistically acceptable range of conditions within which the endpoint is to be identified. In many cases, hundreds to thousands of wafers may be run to establish the desired range. This can again significantly increase the costs of processing the desired wafers.
As another example of the disadvantages of the optical emission approach to detecting the endpoint of the etching process, variations from wafer to wafer and/or the use of a complicated process in which many reactants are involved may make it impossible to find an acceptable range of conditions that can be used to identify the endpoint of the process. If this is the case, the approach of using a predetermined length of time to control the etching must be used. However, as mentioned above, the use of this approach may cause a large number of bad wafers to be produced thereby increasing the costs of processing the wafers.
In view of the foregoing, there are desired improved methods and apparatus for more accurately determining the endpoint of a plasma-enhanced etch process.
SUMMARY OF THE INVENTION
The invention relates, in one embodiment, to a method for determining an endpoint for a plasma etching process. The plasma etching process is employed to etch a substrate in a plasma processing chamber. The method includes detecting, using a mass analyzer, a density of a predefined compound in the plasma processing chamber. The method further includes outputting from the mass analyzer a variable signal responsive to the detecting. There is also included producing, responsive to the variable signal, a control signal. The control signal is outputted when a predefined density criteria is detected in the variable signal. Additionally, there is included initiating an etch termination procedure, responsive to the control signal, thereby ending the plasma etching process at an end of the etch termination procedure.
In another embodiment, the invention relates to a method for determining an endpoint for a plasma etching process. The plasma etching process is employed to etch a substrate in a plasma processing chamber. The method includes directing a beam of light through a region of the plasma processing chamber during the plasma etching process. The region contains byproducts of the plasma etching process, compounds of the byproducts having different light absorbing characteristics. The method further includes detecting an intensity of the beam of light after the beam of light passes through the region and generating from the detecting a variable signal representative of a density of a predefined compound of the compounds in the byproducts. There is also included producing, responsive to the variable signal, a control signal. The control signal being outputted when a predefined density criteria is detected in the variable signal. Additionally, there is included initiating an etch termination procedure, responsive to the control signal, thereby ending the plasma etching process at an end of the etch termination procedure.
In yet another embodiment, the invention relates to a method for determining an endpoint for a plasma etching process. The plasma etching process is employed to etch a substrate in a plasma processing chamber. The method includes employing a first endpoint sensor to determine a first endpoint of the plasma etching process. There is also included employing a second endpoint sensor different from the first endpoint sensor to determine a second endpoint of the plasma etching process. Further, there is included ascertaining whether the first endpoint and the second endpoint are ascertained within a predefined time period. Additionally, there is included initiating an etch termination procedure if the first endpoint and the second endpoint are ascertained within the predefined time period.
These and other features of the present invention will be described in more detail below in the detailed description of the invention and in conjunction with the following figures.
BRIEF DESCRIPTION OF THE DRAWINGS
The features of the present invention may best be understood by reference to the following description of the presently preferred embodiments together with the accompanying drawings.
FIG. 1 is a simplified cross-sectional view of a prior art plasma processing chamber including a optical emission detector arrangement for detecting the endpoint of a plasma etching process.
FIG. 2 is an cross sectional view of a plasma processing chamber designed in accordance with the invention including a mass analyzer for detecting the endpoint of a plasma etching process.
FIG. 3 is an cross sectional view of a plasma processing chamber designed in accordance with the invention including an arrangement having a light source and a light detector for detecting the endpoint of a plasma etching process.
FIG. 4 is a flow diagram illustrating the operation of a plasma processing chamber designed in accordance with the invention including a plurality of independent sensors used to detect and determine the endpoint of a plasma etching process.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
An invention is described herein for providing a method and apparatus for determining the endpoint of a plasma etching process performed on a silicon wafer in a plasma processing chamber. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention. However, it will be obvious to one skilled in the art that the present invention may be embodied in a wide variety of specific configurations. Also, well known plasma etching processes and other processes associated with the production of integrated circuits on silicon wafers will not be described in detail in order not to unnecessarily obscure the present invention.
The inventive endpoint determining technique may be performed in any known plasma processing apparatuses such as, but not limited to, those adapted for dry etching, plasma etching, reactive ion etching, magnetically enhanced reactive ion etching, electron cyclotron resonance, or the like. Note that the this is true irrespective of whether energy to the plasma is delivered through capacitively coupled parallel electrode plates, through ECR microwave plasma sources, or through inductively coupled RF sources such as helicon, helical resonators, and transformer coupled sources. These processing systems, among others, are readily available commercially.
FIG. 2 illustrates a simplified schematic of a plasma processing system 200 designed in accordance with the present invention. For illustrative purposes, like reference numerals will be used throughout the various figures for like components. Generally, system 200 is a system similar to system 100 described above. That is, system 200 includes plasma processing chamber 102 with gas line 104 connected to shower head 106 in chamber 102 for releasing etchant gases into the chamber. As described above for system 100, chuck 108 is used to support a silicon wafer 110 during the processing of the wafer and exhaust port 130 is used to exhaust the byproducts of the etching process from chamber 102. Although not shown in FIG. 2, one or more test ports or view ports may also be provided.
In the embodiment illustrated in FIG. 2, system 200 also includes RF source 126 coupled to shower head 106 and RF source 128 coupled to chuck 108. These RF sources are used to strike a plasma within chamber 102. Although system 200 is described as including RF sources 126 and 128, this is not a requirement. Instead, as described above, it should be understood that the present invention would equally apply regardless of the specific arrangement and power source used to strike the plasma within the chamber.
In accordance with the invention and as will be described in more detail hereinafter, system 200 further includes a mass analyzer 202. In this embodiment, mass analyzer 202 is connected to exhaust port 130 by a sampling port 204. Sampling port 204 allows mass analyzer 202 to be able to sample the gases that are being exhausted through exhaust port 130. Although mass analyzer is described as being connected to exhaust port 130, this is not a requirement. Instead, mass analyzer 202 may be connected to system 200 in any way so long as mass analyzer 202 is able to sample the byproducts of the etching process as they are being produced. For example, mass analyzer 202 may be connected to system 200 such that it samples the byproducts of the etching process directly from chamber 102 rather than from exhaust port 130.
Mass analyzer 202 may be any suitable and readily available mass analyzer designed to be capable of detecting compounds that are produced as byproducts of the etching process. In a preferred embodiment, mass analyzer 202 is a mass analyzer such as the QualiTorr® Orion® series of mass analyzers provided by MKS Instruments of San Jose, Calif. Other mass analyzers, such as the M5250 or the MEXM0500b (available from the ABB Extrel company of Pittsburgh, Pa.), or any other suitable mass analyzer may also be used.
As illustrated in FIG. 2, mass analyzer 202 produces an output signal indicated by arrow 206. This output signal represents the presence of various compounds that make up the exhaust gases that are produced as byproducts of the etching process and are exhausted from the chamber. Signal 206, which may be a continuously variable signal, is provided to a controller or computer 208 which is used to control the operation of system 200. In accordance with the invention, controller 208 uses signal 206 to determine when the endpoint of the etching process has been reached by detecting a predetermined density criteria in signal 206. This predefined density criteria indicates a change in the compounds making up the byproducts of the etching process.
As described above in the background, the reactants of the etching process generally maintain an equilibrium as the wafer is being etched. This equilibrium is maintained until the exposed portions of the layer which are being etched start to clear or be fully removed. At this point, the concentration of the etchant species increases and the concentration of the reaction product species decreases. Alternatively, if the etching process begins to etch into an underlying layer of the wafer formed from a different material, the reaction product species will begin to change. These changes may be reflected in a predefined density criteria to ascertain, from variable signal 206, when to terminate the etch. If the predefined density criteria is ascertained, controller 208 may output a control signal to begin the etch termination procedure, which may immediately terminate the etch or may, if desired, extend the etch some predefined time duration to achieve overetch.
By way of example, a control signal may be outputted when the density threshold of a given compound is detected (such as when the density of the byproduct decreases to a certain threshold or when the density of the etching source gas increases to a certain threshold). As another example, the control signal may be outputted when the change (either increase or decrease) in the density of a predefined compound reaches a certain level. As yet another example, the control signal may be outputted when the shape of variable signal 206 matches a predefined shape. In a preferred embodiment, the predefined density criteria in variable signal 206 are obtained by running test etches on a test wafers.
This novel approach of using a mass analyzer to detect changes in the compounds making up the byproducts of the etching process has several advantages over the prior art optical emission method described above in the background. For example, the use of a mass analyzer eliminates the need to use a window to observe the optical emissions of the etching process. Therefore, the problems associated with the clouding of the window described above are completely eliminated. This eliminates the need to shut down the system regularly for cleaning of the window. Also, the mass analyzer detects various compounds by identifying the mass or density of selected compounds analyzed by the analyzer. This means that the mass analyzer approach is unaffected by optical background noise caused by the plasma etching process as is the case for the optical emission approach. In many cases, this elimination of the background noise problem makes the mass analyzer approach much more reliable compared to the optical emissions approach.
In another advantage, the mass analyzer approach may be used for very complicated processes in which it would be difficult or impossible to identify useful threshold or shape characteristics needed to trigger an endpoint using the optical emission approach. This is because mass analyzers are very accurate at ascertaining the mass or density of a specific compound and are therefore relatively unaffected by the level of complexity associated with the etch process. By way of example, modern mass analyzers have resolutions within 10 parts per billion or better. As another example, some mass analyzers are capable of monitoring multiple independent species, e.g., up to ten different kinds of species, simultaneously. These advantages of the mass analyzer approach make this approach very reliable.
Because the mass analyzer approach eliminates the cloudy window problem and the background noise problem, and because it is very accurate at identifying the mass or density of compounds analyzed, the mass analyzer approach substantially reduces the number of test wafers that must be run in order to identify the proper circumstances that may be used to determine the endpoint of the etching process. For example, in the case of using the optical emission approach to determine the endpoint of the etching process, typically hundreds or thousands of test wafers are run in order to obtain an acceptable range of circumstances that can be used to detect the endpoint of the etching process. However, using the mass analyzer approach, only a few test wafers (for example less than ten test wafers) will typically provide sufficient information to identify the circumstances that can be used to determine the endpoint of the etching process. This substantial reduction in the number of test wafers required to properly identify the endpoint of the etching process significantly reduces the overall cost of processing a given type of wafer.
Referring now to FIG. 3, another embodiment of the invention will be described. FIG. 3 illustrates a simplified schematic of a plasma processing system 300 designed in accordance with the present invention. As was the case for the previously described systems, system 300 includes plasma processing chamber 102 with gas line 104 connected to shower head 106 in chamber 102 for releasing etchant gases into the chamber. As described above for both systems 100 and 200, chuck 108 is used to support a silicon wafer 110 during the processing of the wafer and exhaust port 130 is used to exhaust the byproducts of the etching process from chamber 102. System 300 also includes RF source 126 coupled to shower head 106 and RF source 128 coupled to chuck 108. As mentioned above, the use of RF sources is not a requirement of the invention.
In accordance with the invention and as will be described in more detail hereinafter, system 300 further includes a light source 302, a light detector 304, and two windows 306 and 308. In this embodiment, windows 306 and 308 are located in opposite walls of exhaust port 130. Light source 302 is positioned adjacent to window 306 and light detector 304 is positioned adjacent window 308 such that light source 302 is able to direct a beam of light through exhaust port 130 into light detector 304 as indicated by arrow 310. Although the windows, light source, and light detector are described as being located such that the light source directs a beam of light through the exhaust port, this is not a requirement. Instead, these components may be located such that the light source directs a beam of light through any portion of system 300 so long as the beam of light passes through a region of the system that contains byproducts of the etching process as those byproducts are being produced by the etching process. For example, light source 302, light detector 304, and windows 306 and 308 may be located in system 300 such that they direct a beam of light from one side of plasma processing chamber 102 to the other side of the chamber rather than through exhaust port 130.
In a preferred embodiment, light source 302 takes the form of a laser. Although the light source is described as being a laser, this is not requirement. Instead any suitable light source may be utilized. However, preferably, the light source generates a focused beam of light having a specific known wavelength of light that is at least partially absorbed by one of the reactants of the plasma etching process. In the case of a laser, the laser may be any suitable and readily available laser designed to produce a beam of light having a wavelength of light that is at least partially absorbed by one of the reactants of the plasma etching process.
As illustrated in FIG. 3, light source 302 directs a beam of light of a given wavelength into exhaust port 130 through window 306 as indicated by arrow 310. When certain compounds or reactants making up the byproducts of the etching process are exhausted through exhaust port 130, specific compounds or reactants which absorb light of the given wavelength absorb a portion of the beam of light passing through exhaust port 130. The remaining portion of the beam of light passes through window 308 to light detector 304. Light detector 304 detects the intensity of this remaining portion of the beam of light and outputs a signal, indicated by arrow 312. The relative strength of this output signal represents the density of compounds or reactants that are capable of absorbing the given wavelength of light generated by light source 302.
Signal 312 may then provided to a controller circuit or computer 314 which is used to control the operation of system 300. In accordance with the invention, controller 314 uses signal 312 to ascertain from signal 312 a predefined density criteria (various examples of which have been described earlier in connection with FIG. 3) and to output a control signal. The control signal may be employed to initiate an etch termination procedure, which may immediately terminate the etch process or may, if desired, terminate the etch process after some predefined time duration to achieve the desired etch effect (e.g., overetch).
As described above in the background, specific reactants of the etching process emit light of a specific wavelength when their excited electrons change state. These reactants are also capable of absorbing light of a specific wavelength by having the electrons change state again. Directing a beam of light of a specific wavelength through the exhaust port as described above causes some of the electrons of the specific reactant to change state thereby absorbing some of the beam of light. This is another phenomenon which causes a change in the amount of light that reaches the light detector.
This novel light absorbing approach of directing a light source into the etchant gases to measure the amount of light absorbed by the gases in order to detect changes in the compounds making up the byproducts of the etching process has several advantages over the prior art optical emission method described above in the background. For example, the use of a light source reduces the problem associated with the clouding of the window. This is because the intensity of the light may be steadily increased to compensate for the clouding problem. In the case of the optical emission method of the prior art, the intensity of light produced is limited by the reactions of the reactant being measured. Also, the light source of the present invention produces a controlled a beam of light which is directed through the gases into a light detector at a known location. On the other hand, the optical emission method randomly emits light in all directions so that only a small portion of the emitted light emitted passes through the window. This means that the windows for the light absorbing method of the present invention may be much smaller than the window used for the prior art optical emission method. Because the windows can be smaller, they may be heated fairly easily and maintained at a high temperature which further reduces the clouding problem.
Also, since the beam of light is directed through the gases to a known location, this approach is not nearly as affected by optical background noise caused by the plasma etching process as is the case for the optical emission approach. In many cases, this reduction of the background noise problem makes the light absorbing approach of the present invention much more reliable compared to the conventional optical emissions approach.
In another advantage, the light absorbing approach may be used for very complicated processes in which it would be difficult or impossible to identify useful threshold or shape characteristics needed to trigger an endpoint using the conventional optical emission approach. This is because the beam of light is not affected by the complexity of the reactions within the chamber. Instead, this approach simply measures the amount of a specific wavelength of light that is absorbed as the light passes through the reactant gases.
Because the light absorbing approach reduces the cloudy window problem and the background noise problem, and because it is specifically configured to detect a the presence of a specific compound within the reactant gases, the light absorbing approach also substantially reduces the number of test wafers that must be run in order to identify the proper circumstances that may be used to determine the endpoint of the etching process. For example, as described above, typically hundreds or thousands of test wafers may need to be run in order to obtain an acceptable range of circumstances that can be used to detect the endpoint of the etching process in the case of using the optical emission approach. However, using the light absorbing approach, only a few test wafers may provide sufficient information to identify the circumstances that can be used to determine the endpoint of the etching process. This reduction in the number of test wafers required to identify the endpoint of the etching process reduces the overall cost of processing a given type of wafer.
In another aspect of the invention, a plurality of independent sensors are used to independently determine the endpoint of the etching process. In accordance with the invention, the endpoint of the etching process is identified only when at least two independent sensors indicate that the endpoint has been detected. This approach substantially improves the reliability of the identification process thereby improving the yield for wafers processed using this approach.
FIGS. 4A and 4B illustrate the operation of a system in which multiple independent sensors arrangements are used to determine the endpoint to the etching process. As shown in FIG. 4A, this embodiment includes an overall endpoint detection arrangement 400 that has 4 independent sensor arrangements 402a-d. It should be noted that although four independent sensors are shown, the technique works with as few as two independent sensors (which may be of the same or different types of sensors). Each of these sensors provides a signal, indicated by arrows 404a-d, to a controller 406 which controls the operation of the etching process. Each of sensors 402 may be implemented by any of the above described sensor arrangements. These include the optical emission approach described above with reference to FIG. 1, the mass analysis approach described above with reference to FIG. 2, the light absorbing approach described above with reference to FIG. 3, any other readily available sensor arrangements for detecting an endpoint.
Controller 406 includes a logic circuit which determines when the endpoint of the etching process is reached. FIG. 4B is a flow chart illustrating the operation of this logic circuit within controller 406. As shown in FIG. 4B, the function of the logic circuit of controller 406 starts at block 410 of the flow chart. Initially, as indicated by block 412, a first endpoint signal is received from one of the sensors 402a-d. However, rather than stopping the etching process, controller 406 waits for the detection of the endpoint from another one of the sensors. This is indicated by block 414.
Controller 406 then optionally determines whether the two signals from the two sensors occurred within a designated amount of time. This is indicated by optional block 416. In this optional embodiment, the logic circuit insures that at least two independent sensors independently detect an event that indicates the endpoint of the etching process, with the two events falling within a designated period of time. Once controller 406 determines that the endpoint has been reached, as indicated by block 418, controller 406 then initiates the etch termination procedure. As mentioned earlier, the initiation procedure may cause the etch process to immediately stop or may cause the etch process to proceed an additional predefined time period to achieve a desired etch effect (e.g., overetch). If the signals from the two sensors have not been received within the designated amount of time (for example 20 seconds), the system may, in one embodiment, waits for another signal from another one of the sensors as indicated by block 420 before ascertaining whether the etch termination procedure should be initiated.
While this invention has been described in terms of several preferred embodiments, there are alterations, permutations, and equivalents which fall within the scope of this invention. For instance, although the mass analyzer of system 200 and the light source and light detector of system 300 have been described as being located adjacent to the exhaust port, this is not a requirement. Instead, the present invention would equally apply regardless of the specific location in which the various sensor arrangements are positioned. It is therefore intended that the following appended claims be interpreted as including all such alterations, permutations, and equivalents as fall within the true spirit and scope of the present invention. | Methods for determining an endpoint for a plasma etching process. The plasma etching process is employed to etch a substrate in a plasma processing chamber. The method includes detecting, using a mass analyzer, a density of a predefined compound in the plasma processing chamber. The method further includes outputting from the mass analyzer a variable signal responsive to the detecting. There is also included producing, responsive to the variable signal, a control signal. The control signal is outputted when a predefined density criteria is detected in the variable signal. Additionally, there is included initiating an etch termination procedure, responsive to the control signal, thereby ending the plasma etching process at an end of the etch termination procedure. | 7 |
BACKGROUND OF THE INVENTION
[0001] This invention relates to a cooling structure for a working vehicle having an oil cooler.
[0002] A known cooling structure for a working vehicle having a water-cooled engine includes a cooling fan driven by the engine for cooling a radiator. Cooling air flows generated by the cooling fan are supplied to the radiator and an oil cooler opposed to the radiator to cool oil (see JP 2007-9825, for example).
[0003] In the above construction, the working vehicle has the water-cooled engine requiring many accessories such as the radiator and a water pump. Thus, the working vehicle tends to become large and costly.
SUMMARY OF THE INVENTION
[0004] The object of this invention is to provide a cooling structure for cooling oil without increasing the size and cost of a working vehicle.
[0005] A cooling structure for a working vehicle, according to this invention, with a transmission disposed rearwardly and downwardly of a driver's seat and having a hydrostatic transmission, and an air-cooled engine disposed rearwardly of the transmission, comprises a fan for cooling the engine and a fan for cooling the transmission mounted on a rotary shaft operatively connecting the transmission with an output shaft of the air-cooled engine, the fans being configured such that air flows generated by the fans move from adjacent the transmission toward the engine; an oil cooler for cooling fluid supplied to the hydrostatic transmission, the oil cooler being disposed between the fan for cooling the engine and the fan for cooling the transmission, and disposed to face each of the fans; and an air guiding plate disposed at a position higher than the oil cooler for guiding air to regions of the fans.
[0006] With this characteristic construction, instead of installing a water-cooled engine which requires many accessories such as a radiator and a water pump, oil stored in the change speed devices and oil passing through the oil cooler can be cooled by cooling air flows generated by the fan for cooling the change speed devices.
[0007] Therefore, the oil can be cooled without increasing the size and cost of the working vehicle.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] FIG. 1 is a side elevation of a riding type mowing machine;
[0009] FIG. 2 is a side view in vertical section of a principal portion showing a cooling structure;
[0010] FIG. 3 is a side view in vertical section of the principal portion showing a maintenance state;
[0011] FIG. 4 is a plan view in cross section of the principal portion showing the cooling structure;
[0012] FIG. 5 is a rear view in vertical section of the principal portion showing the cooling structure;
[0013] FIG. 6 is a plan view in cross section of an upper rear portion showing flows of cooling air;
[0014] FIG. 7 is a plan view in cross section of a lower rear portion showing flows of cooling air;
[0015] FIG. 8 is a plan view in cross section of a lower rear portion of a modified construction having a rear cover placed on a support deck, showing flows of cooling air;
[0016] FIG. 9 is a side view in vertical section of a principal portion of the modified construction having the rear cover placed on the support deck, showing flows of cooling air;
[0017] FIG. 10 is a side view in vertical section of a principal portion of a modified construction having guide pieces provided for an upper cover, showing flows of cooling air;
[0018] FIG. 11 is a plan view in cross section of the principal portion of the modified construction having the guide pieces provided for the upper cover, showing flows of cooling air; and
[0019] FIG. 12 is a side view of a principal portion of a modified construction having right and left lower edges of an upper cover inclined upward, showing flows of cooling air.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0020] An embodiment in which this invention is applied to a riding type mowing machine which is one example of working vehicles will be described hereinafter.
[0021] FIG. 1 shows a side elevation of the riding type mowing machine. As shown in FIG. 1 , the riding type mowing machine in this embodiment is constructed the mid-mount type having a mower 5 vertically movably attached through a link mechanism 4 to a vehicle body 1 between a pair of right and left front wheels 2 and a pair of right and left rear wheels 3 .
[0022] The vehicle body 1 includes a front frame 6 formed of square pipe or the like and disposed in a front part thereof. The front frame 6 supports the link mechanism 4 , and has right and left front wheels 2 arranged at right and left ends of a front end thereof to be dirigible about vertical axes. The link mechanism 4 can raise and lower the mower 5 in parallel by operation of a single-acting hydraulic cylinder 7 .
[0023] The front frame 6 has a boarding step 8 formed of sheet metal and covering substantially the whole of the front frame 6 from above. The boarding step 8 has a rubber mat (not shown) laid over the surface thereof, and has, arranged in a middle front region thereof, a brake pedal 9 biased back to a non-braking position, and a lock pedal 10 for engaging and holding the brake pedal 9 in a braking position against the biasing force. A positionally adjustable driver's seat 11 is disposed rearwardly and upwardly of the boarding step 8 . Fenders 12 and shift levers 13 are arranged at right and left sides of the driver's seat 11 , respectively. An arch-like protection frame 14 is erected at the back of the driver's seat 11 . Thus, this riding type mowing machine has a driving platform 15 formed on a front portion of the vehicle body 1 .
[0024] As shown in FIGS. 1 through 7 , the vehicle body 1 includes a rear frame 16 connected to the rear end of the front frame 6 . The rear frame 16 has a pair of right and left side members 17 formed of sheet metal, and support deck 18 supported by rearward parts of the right and left side members 17 . The support deck 18 is bent to be substantially L-shaped in side view to have a bottom wall 18 A and a front wall 18 B, An air-cooled gasoline engine 19 is mounted on the bottom wall 18 A to have an output shaft 19 A thereof projecting forward of the vehicle body.
[0025] A transmission device (an example of change speed devices) 20 is disposed forwardly and downwardly of the engine 19 for slowing down power from the engine 19 and dividing the power into propelling power and working power. The transmission device 20 houses a clutch (not shown) for connecting and disconnecting the working power. Hydrostatic stepless transmissions (which are one example of change speed device, hereinafter abbreviated as HSTs) 21 are arranged at right and left sides of the transmission device 20 for receiving the propelling power from the transmission device 20 . A reduction gear 22 is connected to an outer side of each HST 21 for receiving the power after a change speed by the corresponding HST 21 . Each reduction gear 22 has a corresponding one of the rear wheels 3 drivably attached thereto. Each HST 21 has a shift rod (not shown) interlocked to a corresponding one of the shift levers 13 to be shiftable in response to forward and rearward rocking of the corresponding shift lever 13 .
[0026] With this construction, the right and left shift levers 13 are rockable forward and rearward to shift the HST 21 corresponding to each control lever 13 . In this way, the right and left rear wheels 3 can be driven at variable speed independently of each other.
[0027] That is, this riding type mowing machine has the right and left front wheels 2 dirigible in a follow-up mode, and the right and left rear wheels 3 drivable at variable speed independently of each other. Consequently, the mowing machine can produce, as desired, a stopping state with the right and left rear wheels 3 stopped, a straight moving state with the right and left rear wheels 3 driven at equal speed forward or backward, a large radius turn state with the right and left rear wheels 3 driven at different speeds forward or backward, a pivot turn state with one of the right and left rear wheels 3 stopped and the other driven forward or backward, and a spin turn state with one of the right and left rear wheels 3 driven forward and the other backward,
[0028] The transmission device 20 has a PTO shaft 20 A mounted in a lower front position thereof for taking the working power out for the mower 5 . The PTO shaft 20 A transmits the working power from the transmission device 20 to the mower 5 through a telescopic transmission shaft 23 and universal joints 24 attached to opposite ends of the transmission shaft 23 . That is, the mower 5 receives constant-speed power irrespective of traveling speed and running state.
[0029] The rear frame 16 includes a rear cover 25 disposed at the rear end thereof and having right and left side walls 25 A and a rear wall 25 B. A plurality of exhaust holes 25 a are formed in the rear wall 25 B of the rear cover 25 . An upper cover 26 covering an upper portion of the engine 19 from above is connected to the rear cover 25 to be pivotable open and close about an upper end of rear cover 25 . The upper cover 26 has a plurality of exhaust holes 26 a formed in a rear wall 26 A thereof. A partition wall 28 is erected on the front wall 18 B of the support deck 18 for forming an engine room 27 with the rear frame 16 , rear cover 25 and upper cover 26 . In the engine room 27 , an air cleaner 29 is disposed above the engine 19 . A muffler 30 is disposed rearwardly of the engine 19 .
[0030] Maintenance of the air cleaner 29 such as changing of elements can be carried out easily by opening the upper cover 26 (see FIG. 3 ). The air cleaner 29 employed is the large-sized cyclone type which is made possible by using a large space formed above the engine 19 inside the engine room 27 .
[0031] Though not shown, the rear frame 16 includes a holding mechanism holding the rear cover 25 in a closed position.
[0032] As shown in FIGS. 2 through 4 , the engine 19 includes a pair of right and left legs 19 B for forming a ventilating space S 1 between its bottom and the support deck 18 . The engine 19 further includes, disposed in front thereof, an engine cooling fan 19 C rotatable with the output shaft 19 A of engine 19 , and an air guide housing 19 D covering the cooling fan 19 C from front. The cooling fan 19 C in rotation draws ambient air into the air guide housing 19 D through a circular air intake 18 a formed in the front wall 18 B of the support deck 18 and a circular air intake 19 a formed in the front of the air guide housing 19 D, and causes the ambient drawn in to flow toward the engine 19 as cooling air. The air guide housing 19 D guides the cooling air from the cooling fan 19 C to areas around the engine 19 to cool the engine 19 . Part of the cooling air having passed through the areas around the engine 19 is led to areas around the muffler 30 , to cool the muffler 30 , by an air guide cover 31 attached to an upper rear end of the engine 19 for covering the muffler 30 from above. The cooling air having cooled the engine 19 , muffler 30 and so on is discharged outside through the exhaust holes 25 a of the rear cover 25 and the exhaust holes 26 a of the upper cover 26 . In this way, despite being the air-cooled type, the engine 19 , muffler 30 and so on can be cooled efficiently.
[0033] A sleeve shaft 19 E is connected to the front end of the cooling fan 19 C to be rotatable with the cooling fan 19 C about the output shaft 19 A. The sleeve shaft 19 E supports a circular, porous dust-proof plate 19 F for preventing inflow of dust from the air intake 19 a of the air guide housing 19 D to the interior of the housing 19 D caused by the sucking action of the cooling fan 19 C.
[0034] As shown in FIGS. 2 through 5 , a dust-proof plate 32 is attached to the bottom of the rear frame 16 and between the right and left side members 17 for covering, from below, a space S 2 formed between the transmission device 20 and right and left HSTs 21 , and the support deck 18 . The dust-proof plate 32 includes a bottom wall 32 A extending between the right and left side members 17 , a front wall 32 B extending from the forward end of the bottom wall 32 A upward toward the transmission device 20 and right and left HSTs 21 , and a rear wall 32 C extending from the rear end of the bottom wall 32 A upward toward the support deck 18 . The front wall 32 B has a recess 32 a formed therein for receiving the transmission device 20 .
[0035] This construction can prevent ambient air containing a large quantity of grass clippings and the like from being drawn from under the vehicle body toward the air intake 19 a of the air guide housing 19 D as cooling air by the sucking action of the cooling fan 19 C. Instead, ambient air containing a less quantity of grass clippings and the like can be supplied as cooling air from above the vehicle body through between the driver's seat 11 and partition wall 28 toward the air intake 19 a of the air guide housing 19 D.
[0036] As a result, the quantity of dust such as grass clippings adhering to or depositing on and around the engine 19 can be reduced drastically, to reduce the time and trouble taken in cleaning.
[0037] As shown in FIGS. 1 through 6 , a dust removing cover 34 having a dust removing net 34 A is formed integral with the front end of the upper cover 26 . When the upper cover 26 is in the closed position, the dust removing cover 34 forms an ambient air introducing space 33 with the partition wall 28 , and removes dust from the ambient air flowing from above the vehicle body through between the driver's seat 11 and partition wall 28 . Thus, cleaner ambient air passing through the ambient air introducing space 33 can be supplied as cooling air from between the driver's seat 11 and partition wall 28 toward the air intake 19 a of the air guide housing 19 D.
[0038] Though not shown, the dust removing cover 34 may be formed separately from the upper cover 26 , and detachably erected on the rear frame 16 .
[0039] As shown in FIGS. 2 through 4 , an opening 32 b is formed in the bottom wall 32 A of dust-proof plate 32 , and a lid 32 D is provided for opening and closing the opening 32 b . The lid 32 D is preferably plate shaped. The lid 32 D is vertically pivotable between open and closed positions about a pivot shaft 32 E extending right and left at the forward end of the bottom wall 32 A. The lid 32 D is biased upward toward the closed position by a torsion spring 32 F mounted on the pivot shaft 32 E. The lid 32 D has a control rod 32 G extending from a left front position of the lid 32 D upward toward the ambient air introducing space 33 for enabling the lid 32 D to be opened against the biasing force of the torsion spring 32 F. The control rod 32 G has an engaging piece 32 H welded to an upper position thereof for engaging, from below, an engageable element 35 provided in a rear upper left position of the transmission device 20 , to hold the lid 32 D in the open position with the biasing force of the torsion spring 32 F.
[0040] With this construction, dust having deposited on an inner surface of the lid 32 D can be removed easily through the opening 32 b of the bottom wall 32 A, by opening the upper cover 26 to move the dust removing cover 34 away from the rear frame 16 , and operating the control rod 32 G to open the lid 32 D. Dust having deposited on an inner surface of the dust-proof plate 32 can be removed easily through the opening 32 b of the bottom wall 32 A by holding the lid 32 D in the open position.
[0041] As shown in FIGS. 2 through 5 , power is transmitted from the engine 19 to the transmission device 20 through a transmission shaft 36 relatively slidably splined to the sleeve shaft 19 E and a pair of front and rear universal joints 37 . The front universal joint 37 has a cooling fan 38 rotatable therewith. The cooling fan 38 in rotation draws ambient air from areas forward of the transmission device 20 and right and left HSTs 21 , and causes the ambient air to flow as cooling air around the transmission device 20 and right and left HSTs 21 to cool the transmission device 20 and right and left HSTs 21 .
[0042] The transmission device 20 has, mounted on a lower rear portion thereof a hydraulic pump 39 for sucking and feeding under pressure oil (or fluid) stored inside the transmission device 20 , and a first oil filter 40 of the cartridge type for filtering the oil sucked by the hydraulic pump 39 . The oil fed under pressure by the hydraulic pump 39 can be supplied to the hydraulic cylinder 7 for vertically moving the mower, right and left HSTs 21 and clutch by operation of a control valve (not shown) and the like. Oil drained from the hydraulic cylinder 7 for vertically moving the mower, right and left HSTs 21 and clutch is returned to the interior of the transmission device 20 . A second oil filter 41 of the cartridge type is mounted on an upper front portion of the transmission device 20 for filtering the oil supplied to the right and left HSTs 21 .
[0043] Maintenance of the first oil filter 40 such as changing of elements can be carried out easily through the opening 32 b of the bottom wall 32 A by operating the control rod 32 G to hold the lid 32 D in the open position (see FIG. 3 ).
[0044] Between the partition wall 28 and cooling fan 38 for the change speed devices, an oil cooler 42 is disposed for cooling fluid supplied in circulation to the transmission device 20 , hydraulic cylinder 7 , right and left HSTs 21 and clutch. The oil cooler 42 is formed to extend to the ambient air introducing space 33 from between the engine cooling fan 19 C and cooling fans 38 for the change speed devices, and have lower portions straddling the universal joint 37 so that considerable portions thereof overlap the cooling fan 38 for the change speed devices when seen in the fore and aft direction.
[0045] Thus, upper portions of the oil cooler 42 are supplied with engine cooling air flowing through the ambient air introducing space 33 into the air intake 19 a of the air guide housing 19 D by the sucking action of the cooling fan 19 C opposed to the oil cooler 42 . Lower portions of the oil cooler 42 can be supplied with cooling air for the change speed devices having flowed around the transmission device 20 and right and left HSTs 21 by the sucking action of the cooling fan 38 for the change speed devices.
[0046] The partition wall 28 includes a pair of right and left first air guiding plates 28 A arranged adjacent right and left ends of the oil cooler 42 , a pair of right and left second air guiding plates 28 B sloping inward and downward from lower edges of the respective first air guiding plates 28 A toward the air intake 18 a of the support deck 18 , and a third air guiding plate 28 C extending between the right and left first air guiding plates 28 A and sloping rearward and downward from above the oil cooler 42 toward the air intake 18 a of the support deck 18 .
[0047] Thus, the right and left first air guiding plate 28 can prevent the heat of the engine room 27 from being drawn in through the air intake 19 a of the air guide housing 19 D by the sucking action of the engine cooling fan 19 C. The right and left second air guiding plates 28 B and third air guiding plate 28 C can form an cooling air guide passage 43 extending from between the driver's seat 11 and partition wall 28 to the air intake 19 a of the air guide housing 19 D, such that the passage 43 is tapered to become narrower from a region adjacent the cooling fan 38 for the change speed devices which is upstream in the flowing direction of cooling air, to a region adjacent the engine cooling fan 19 C which is downstream in the flowing direction of cooling air. This increases the speed of the cooling air passing through the air passage 43 of the cooling air, to increase the flow rate per unit time of the cooling air supplied to the engine 19 and oil cooler 42 . As a result, the engine 19 , and the oil cooler 42 located in the air passage 43 , can be cooled efficiently by the cooling air.
[0048] The third air guiding plate 28 C is detachably attached to the partition wall 28 by engaging a pair of right and left engaging claws 28 b formed by bending rear ends of the third air guiding plate 28 C, into a pair of right and left slits 28 a formed in the partition wall 28 . By removing the third air guiding plate 28 C from the partition wall 28 , replenishment of grease for the sleeve shaft 19 E and universal joint 37 located under the third air guiding plate 28 C may be carried out easily through grease nipples 19 b and 37 a of the sleeve shaft 19 E and universal joint 37 . Dust adhering to the dust-proof plate 19 F, oil cooler 42 and so on may also be removed easily after removing the third air guiding plate 28 C from the partition wall 28 (see FIG. 3 ).
[0049] As shown in FIG. 5 , the right and left first air guiding plates 28 A have buckle type connectors 28 D for engaging a pair of right and left engageable elements 28 c formed on the forward end of the third air guiding plate 28 C to connect the forward end of the third air guiding plate 28 C to the right and left first air guiding plates 28 A. This arrangement can prevent generation of noise due to vibration of the third air guiding plate 28 C while the vehicle is traveling, for example.
[0050] Though not shown, the third air guiding plate 28 C may be attached to the partition wall 28 to be pivotable between an operative position extending from the partition wall 28 to the upper end of the oil cooler 42 , and a retracted position standing along the partition wall 28 . The partition wall 28 may have an engaging device for engaging the third air guiding plate 28 C to retain the third air guiding plate 28 C in the retracted position.
[0051] As shown in FIGS. 2 , 3 , and 7 , the bottom wall 18 A of the support deck 18 has a rear end bent downward. A space S 3 is formed between the rear end of the bottom wall 18 A and the rear cover 25 . The cooling air having passed through the space S 1 between the bottom of the engine 19 and the bottom wall 18 A of the support deck 18 is guided by the rear end of the bottom wall 18 A to flow promptly rearward and downward from the bottom wall 18 A, and is subsequently discharged outside the vehicle from spaces S 4 formed rearward and downward between the rear frame 16 and rear cover 25 . That is, the cooling air for the engine can be made to flow smoothly and promptly through the space S 1 between the bottom of engine 19 and the bottom wall 18 A of support deck 18 , to cool the bottom of engine 19 (lower surface of the crank case) efficiently.
[0052] As shown in FIGS. 8 and 9 , where the rear cover 25 has a forward end placed on a rear end portion of the bottom wall 18 A of support deck 18 , a recess 25 b is formed in the forward end of the rear cover 25 for letting out the cooling air having passed through the space S 1 between the bottom of engine 19 and the bottom wall 18 A of support deck 18 . As a result, the cooling air having passed through the space S 1 between the bottom of engine 19 and the bottom wall 18 A of support deck 18 flows promptly toward the rear cover 25 through the recess 25 b of the rear cover 25 , and is promptly discharged outside the vehicle from the exhaust holes 25 a of the rear cover 25 . That is, the cooling air for the engine can be made to flow smoothly and promptly through the space S 1 between the bottom of engine 19 and the bottom wall 18 A of support deck 18 , to cool the bottom of engine 19 efficiently.
[0053] As shown in FIGS. 1 and 7 , the rear cover 25 is has right and left side walls 25 A inclined to converge with the right and left width progressively narrowing rearward. Thus, as the vehicle travels, ambient air present laterally outward of the engine 19 flows from a space S 5 ( FIG. 1 ) formed between each side member 17 of the rear frame 16 and the upper cover 26 toward the rear of engine 19 and the muffler 30 disposed rearwardly of the engine, to be discharged promptly through the exhaust holes 25 a of the rear cover 25 . That is, by action of the rear cover 25 , ambient air present laterally outward of the engine 19 can be made to flow smoothly and promptly to the exhaust holes 25 a of the rear cover 25 . These air flows can promote the speed of the engine cooling air flowing from the air intake 19 a of the air guide housing 19 D toward circumferential areas of the engine 19 . As a result, the engine 19 and muffler 30 can be cooled with increased efficiency.
[0054] As shown in FIGS. 1 and 6 , the upper cover 26 is formed to diverge with the right and left width progressively broadening forward in plan view, to form rearwardly converging spaces S 6 between right and left lower edges 26 B thereof and the rear frame 16 . Thus, as the vehicle travels, ambient air present laterally outward of the engine 19 flows from the spaces S 6 between the right and left lower edges 26 B of the upper cover 26 and the rear frame 16 toward upper portions of the engine room 27 , to be discharged promptly through the exhaust holes 26 a of the upper cover 26 . That is, by action of the upper cover 26 , ambient air present laterally outward of the engine 19 can be made to flow smoothly and promptly to the exhaust holes 26 a of the upper cover 26 , to prevent the heat remaining in the upper portions of the engine room 27 . As a result, it is possible to avoid a situation where the heat stagnates in the upper portions of the engine room 27 housing the air cleaner 29 , and engine combustion efficiency lowers owing to a temperature increase of the air supplied to the engine 19 .
[0055] As shown in FIGS. 10 and 11 , a plurality of guide pieces 26 b may be arranged along the right and left lower edges 26 B of the upper cover 26 for guiding the ambient air flowing in from the spaces S 6 between the right and left lower edges 26 B and the rear frame 16 to flow toward the rear wall 26 A of the upper cover 26 . Thus, ambient air present laterally outward of the engine 19 is made to flow smoothly and promptly toward the exhaust holes 26 a of the upper cover 26 , thereby to avoid the above-noted lowering of engine combustion efficiency with increased assurance.
[0056] As shown in FIG. 12 , the upper cover 26 may have the right and left lower edges 26 B inclined upward and forward at predetermined angles θ1-θ3, to facilitate the ambient air present laterally outward of the engine 19 flowing toward the upper portions of the engine room 27 , thereby to avoid the above-noted lowering of engine combustion efficiency with increased assurance.
[0057] As shown in FIGS. 2 and 3 , a communicating tube 28 F is disposed above the third air guiding plate 28 C of partition wall 28 for communicating the engine room 27 and ambient air introducing space 33 . The air cleaner 29 has an air intake hose 44 connected to an inlet pipe 29 A thereof and inserted to the communicating tube 28 F. Thus, the engine 19 is supplied with fresh ambient air, through the air cleaner 29 , immediately after stripped of dust by the dust removing cover 34 above the vehicle body where little grass clippings are scattered, and not influenced by the engine 19 or oil cooler 42 . As a result, clogging of the air cleaner 29 can be inhibited effectively. Moreover, it is possible to avoid lowering of engine combustion efficiency due to supplying the engine with heated air, which would occur when air inside the engine room 27 or the ambient air having passed through the oil cooler 42 is supplied to the engine 19 .
[0058] Though not shown, metal fittings for supporting the air cleaner 29 may be attached to an upper rear surface of the partition wall, so that the air cleaner 29 may be disposed on the upper rear surface of the partition wall 28 .
OTHER EMBODIMENTS
[0059] [1]The working vehicles to which this invention is applicable include a mid-mount mower having a mower unit 5 disposed between right and left front wheels 2 and right and left rear wheels 3 of a four-wheel drive type vehicle body 1 , a front mower, a tractor, a riding type rice planting machine and so on.
[0060] [2]The oil cooler 42 may be disposed opposite the cooling fan 38 for the change speed devices across the change speed devices 20 and 21 .
[0061] [3]The oil cooler 42 may be disposed opposite the cooling fan 38 for the change speed devices without straddling the universal joint 37 . | A cooling structure for a working vehicle with a transmission disposed rearwardly and downwardly of a driver's seat and having a hydrostatic transmission, and an air-cooled engine disposed rearwardly of the transmission. The cooling structure comprising a fan for cooling the engine and a fan for cooling the transmission mounted on a rotary shaft operatively connecting the transmission with an output shaft of the air-cooled engine, the fans being configured such that air flows generated by the fans move from adjacent the transmission toward the engine; an oil cooler for cooling fluid supplied to the hydrostatic transmission, the oil cooler being disposed between the fan for cooling the engine and the fan for cooling the transmission, and disposed to face each of the fans; and an air guiding plate disposed at a position higher than the oil cooler for guiding air to regions of the fans. | 5 |
REFERENCE TO COPENDING APPLICATIONS
To the extent that the integrated circuit package assembly handled by the insertion tool of the present invention may utilize a heat sink member of the types disclosed in copending applications, Ser. No. 375,491, "Heat Exchanger for Integrated Circuit Packages" now U.S. Pat. No. 4,421,161 and Ser. No. 395,723, "Wire Form Heat Exchange Element" now U.S. Pat. No. 4,465,130 both by Samuel R. Romania and Grant M. Smith, the foregoing applications, which are assigned to the same assignee as the present application, are referenced herein.
BACKGROUND OF THE INVENTION
In the manufacture of electronic equipment which employs integrated circuit packages, it is necessary to insure that the longitudinal axes of the package leads are oriented respectively at right angles to the planar package surfaces. This lead alignment must be preserved both prior to, and during the insertion of the leads into homologously arranged holes in an interconnection medium, such as a printed circuit board. The problems associated with operator handling of such packages become more acute as the package size, and hence, the number of leads, increase. Such leads tend to be relatively fragile, and consequently are easily bent or otherwise rendered unusable.
In an effort to minimize damage to the package leads, an actual manufacturing process makes use of a block of material having a plurality of apertures for receiving and protecting the leads prior to the mounting of the package on the printed circuit board. However, it will be appreciated that at the latter time, an operator must grasp the protective block and pull it away from the leads. Thereafter, the operator must visually align the package with its mounting position on the board, and insert the leads into corresponding apertures. Such a procedure is tedious and time consuming, and has the potential of damage to the leads, both during the removal of the protective block and the subsequent insertion.
What is required is a production tool which will grasp a complete integrated circuit package assembly, and, which under operator control, will eject the block protecting the leads in a manner to preserve the lead orientation. The tool should then facilitate the alignment of the integrated circuit package leads with the mounting holes in the printed circuit board, and finally, release the package in preparation for the next insertion. The present device fills such a need.
SUMMARY OF THE INVENTION
In accordance with the present invention, there is provided a convenient, time-saving tool which, after loading with a previously prepared integrated circuit package assembly, requires no physical contact by the operator with the assembly during its insertion.
With reference to an actual operative embodiment of the invention, the insertion tool is comprised of an elongated body member of rectangular cross section and a cylindrical shaft, spring-loaded by a coaxial spring, and slidably disposed within a central aperture of said body member. The body member exhibits a narrowed cross section at one extremity thereof. A pair of substantially planar side plates are immovably affixed to the latter narrowed extremity of respective opposite sides of said body member and project therebeyond. The outer surfaces of the side plates are thus coextensive with the principal portions of the sides of the body member. Each of the side plates includes a longitudinal channel for accommodating a slidable, elongated ejector rod. A cover plate retains the rod within the channel. Further, each of the side plates includes at its "free" extremity, a pair of foot-like extensions, such that the assembled tool extremity comprises four extensions (including three with locator pins) which describe the corners of a rectangle substantially the same physical size as the package to be inserted.
The pair of ejector rods are coupled to the aforementioned spring-loaded shaft. A generally "H" shaped support member is immovably affixed between the side plates. A pair of gripper members are pivotally attached to respective opposite sides of said support member within the legs of the "H". Each gripper member has along an extremity thereof, a jaw-like section for engaging opposite sides of the package to be inserted. The gripper members include means for tending to bias the jaw-like sections to a "closed" condition.
A spring-loaded pressure/ejection plate is movably coupled to the aforementioned support member and is disposed within the rectangular cavity in the tool body formed by the side plates and the gripper members.
In use, assuming that the jaws of the gripper member are "open", the operator places the tool over the package assembly. Contact with the upper surface of the assembly with the pressure/ejection plate, causes the latter to release the jaws of the gripper member, which close upon opposed edges of the chip substrate.
With the package secured in place, the lead protector is ejected by depressing the protruding portion of the shaft. The ejector rods push the protective block off in line with the longitudinal axes of the leads.
Finally, the locator pins protruding from three of the four foot-like extensions of the tool provide keying to corresponding apertures in a printed circuit board. Once positioned, the tool is actuated by depressing the jaw-unlatch lever, thereby opening the jaw-like sections and allowing the pressure/ejection plate to insert the package into its proper position on the board.
The jaw-like sections remain "open" in preparation for the next package loading and insertion.
Although the present device has been described in terms of hand operation, the principles of operation embodied therein may be employed in automatic insertion equipment or as part of a robotic assembly. In these cases, activation of the device may be implemented by any of several well known means, such as pneumatic, hydraulic or electrical. Other features and advantages of the invention will become more fully apparent in the detailed description of the tool and its mode of operation which follow.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a pictorial view of the insertion tool of the present invention shown in relation to an integrated circuit package assembly.
FIG. 2 is a side view with portions broken away, of the insertion tool, the latter being in an operator-initiated "open" state prior to the loading of the package assembly.
FIG. 3 is a section view taken along the lines 3--3 of FIG. 2 to better illustrate the internal structure of the insertion tool.
FIG. 4 is a side view of the tool, with portions broken away, illustrating its "closed" state, wherein the package assembly is captivated thereby.
FIG. 5 is a section view of the tool, taken along the line 5--5 of FIG. 4, depicting particularly the removal of the protective block in preparation for the insertion of the package.
FIG. 6 is a partial view of the tool, with portions broken away, illustrating its return to an "open" state and the resultant ejection of the package into its desired position in a printed circuit board.
DESCRIPTION OF THE PREFERRED EMBODIMENT
As seen in the pictorial view of FIG. 1, the insertion tool 10 of the present invention appears in relation to an integrated circuit package assembly 12. The latter includes an integrated circuit package comprised of a chip or die (not shown) mounted on a substrate 14 and having a plurality of leads 15. Also, in an actual production environment, the assembly comprises a wire-form heat sink member 18 of the type described and claimed in the aforementioned referenced applications, and a multi-apertured block-like member 20 formed, for example, of a thermoplastic resin. The block 20 is designed to protect the package leads 16 from damage and to maintain their orientation from the time of package manufacture to the insertion of the leads 16 into corresponding apertures 22 of a printed circuit board 24 as seen in FIG. 6. The internal structure of the device is apparent for example in the side view of FIG. 2 and the section view of FIG. 3.
With general reference to FIGS. 1-3 inclusive and specific reference to other figures as indicated, the insertion tool 10 is comprised of an assembly of two basic parts, namely, an elongated body member 26 of rectangular cross section and a cylindrical shaft 28. The outer extremity of the body member includes two relatively thin planar sections 26a extending beyond and at right angles to respective opposite sides thereof. The latter sections cooperate with the planar extremity 28a of shaft 28 to facilitate the manual depression of the shaft during operation of the device.
Body member 26 includes a pair of central contiguous concentric bores 26' and 26". Shaft 28 is provided with a pair of contiguous cylindrical sections, 28' and 28". The latter sections are accommodated respectively by bores 26' and 26" of body member 26. Shaft 28 is spring-loaded during operation by means of a coaxial coil spring member 30 which substantially encompasses shaft section 28", and lies between the inner extremity of bore 26' and the shoulder provided by shaft section 28'.
The body member 26 exhibits a narrowed cross section at one extremity thereof. A pair of substantially planar side plates 32 are immovably affixed to the latter narrowed extremity of respective opposite sides of said body member 26 and project therebeyond. Each of the side plates 32 includes a longitudinal groove or channel 34 (FIG. 3) for accommodating a slidable ejector rod 36, as seen particularly in FIGS. 4 and 5. A cover plate 38 retains the rod 36 within the channel 34. Screws 40 permit the fastening of the cover plate 38 to the side plate 32 and in turn to the body member 26. Further, each of the side plates 32 includes at its "free" extremity, a pair of foot-like extensions 32a. The extremity of the assembled tool 10 thus comprises four extensions, three of which contain locator pins 32b. It is apparent that the extensions 32a describe the corners of a rectangle substantially the same physical size as the package to be inserted. As seen in FIG. 1, the package assembly is keyed for orientation with the insertor 10 by the three notched corners and one chamfered corner on both the substrate 14 and block 20--the latter being accommodated by complementary geometries in the foot-like extension 32a.
As seen in detail in the section view of FIG. 5, the ejector rods 36 are coupled to the shaft section 28' by a pin 42, press-fitted into corresponding apertures in the last mentioned members. Elongated slots 44 (as also seen in FIG. 4) on opposite sides of the body member 26 and leading into bore 26' provide clearance for pin 42.
A generally "H" shaped support member 46, as seen for example in FIGS. 2 and 3, is immovably affixed between the side plates 32. Flanges 46a (FIG. 1) lock member 46 into the side plates 32 via groove 32c therein. Also, screws 48 situated at the respective bottom surfaces of the channels 34 of side plates 32, fasten the latter to the support member 46, as seen in FIG. 5.
A pair of gripper members 50 are pivotally attached by means of pins 52 to respective opposite sides of the support member 46, within the legs of the "H". Each gripper member 50 has along an extremity thereof, a jaw-like section 50a with a plurality of teeth 50b for engaging opposite sides of the package while avoiding the transverse portions 16' of the leads 16. Each gripper member 50 includes a centrally disposed tang 50c which accommodates the respective extremities of at least a pair of springs 54, the opposite extremities of which rest upon an inner surface of the support member 46. The purpose of springs 54 is to bias the jaw-like sections 50a to a "closed" position with respect to the edges of the integrated circuit package substrate 14.
A pressure/ejection plate 56 is attached to the threaded portion of a bolt 58, slidably mounted in aperture 46' of the support member 46 and retained therein by its head. The plate 56 is spring loaded by virtue of springs 60 interposed between adjacent surfaces of the plate 56 and support member 46. As seen particularly in FIGS. 1 and 2, a jaw-unlatch, lever-type mechanism 64 is provided. The latter, which is spring-loaded by springs 64 (FIG. 5) pivots about screws 66, bringing the rounded portions of adjustable set screws 68 into wiping contact with the tapered extremities 50d of the gripper members 50. The compressive force provided by springs 60 is such that upon the overcoming of the closing bias of springs 54 resulting from the cam-like action of the jaw-unlatch mechanism 62, the pressure/ejection plate 56 moves toward the forward extremity of the tool 10. This action permits the projecting pieces 56a of plate 56 to bear against the lower portions of the gripper members 50 and to cause the jaw-like sections 50a thereof to assume an "open" position. The latter, as seen in FIG. 2, may be regarded as a preset condition.
With reference to FIG. 4, while the tool is in the last mentioned preset condition, contact by the surface of the pressure/ejection plate 56 with the top of the assembly 12, such as the upper surfaces of the heat sink wire form 18, causes plate 56 to move upward on bolt 58 and to compress springs 60. The projecting pieces 56a of plate 56 are trapped within the shallow depressions 50' in the gripper members 50 and springs 54 again bias the latter to a closed condition, wherein the jaw-like sections 50a enclose respective edges of the substrate 14.
In order to use the tool, as seen in its rest condition of FIG. 1, the operator pulls the lever of the jaw-unlatch mechanism 62 toward the finger grip extensions 26a of the body member 26. The tapered extremities 50d of the gripper members 50 are wiped by the rounded portions of the set screws 68 and driven toward the body member 26, while compressing springs 54. The tool is now in its preset condition as described hereinbefore. The jaw-like sections 50a are open, as seen in FIG. 2.
The operator then places the tool 10 over the integrated circuit package assembly 12. The four foot-like extensions 32a of the side plates 32 straddle the assembly. As seen in FIG. 4, contact of the uppermost surface of the package assembly, (or of a high profile component itself), with the lower surface of the pressure/ejection plate 56, and upward movement of the latter, permits the jaw-like sections 50a to close upon opposed edges of the assembly 12.
As seen in FIG. 5, with the package assembly 12 secured within the tool 10, the operator depresses the portion 28a of shaft 28 in opposition to spring 30 by utilizing the finger grips 26a of body member 26. Movement of shaft 28, actuates both ejector rods 36 via pin 42, which push the protective block 20 from the package leads 16. The tool 10 is designed such that the block 20 (as seen in phantom) has been ejected straight off and in line with the respective longitudinal axes of the leads, thereby maintaining the required lead orientation for their subsequent insertion. No physical contact by the operator with the protective block is required during its removal. The package is now ready for insertion.
With reference to FIG. 6, the foot-like extensions 32a have been positioned on the printed wiring board 24 by virtue of the locator pins 32b disposed in three of the four extensions to provide a keying function. The locator pins 32b enter three apertures in the board 24 provided for this purpose. The package leads 16 are thereby aligned with and disposed above corresponding holes 22 in the board. The operator then actuates the lever of the jaw-unlatch mechanism 62 allowing the jaw-like sections 50a of the gripper members 50 to open, and the pressure/ejection plate 56 to eject the package and insert the leads 16 into the printed circuit board holes 22. Here again, no physical contact of the operator is required with the package.
After insertion takes place, the tool 10 is in its preset condition, that is, the jaw-like sections 50a remain open because of the latching feature of the pressure/ejection plate 56. The insertion tool 10 may then be removed from the printed circuit board 24 and is ready for the loading of the next package assembly.
Finally, it is believed that the insertion device described herein is a convenient, non-damaging, time-saving means of inserting component assemblies into the interconnection medium in which they will be utilized. It should be understood that depending upon the particular application, changes and modifications of the tool may be required. For example, actual operative embodiments of the present tool have been used successfully to handle an integrated circuit package assembly comprised of a 68 lead package, approximately one inch square in size and having a heat sink and protective block for the leads. However, the features described herein may be applied to inserters for large size packages containing a greater number of pairs. It is thus apparent that the dimensions of various parts of the tool, which bear a relation to the geometry of the package to be inserted, must be chosen accordingly. Such variations as are within the skill of the designer, and which do not depart from the true scope and spirit of the invention are intended to be covered by the claims which follow. | A device for handling electronic circuit components, such as integrated circuit packages, and for facilitating the insertion of the pins or leads thereof into corresponding apertures of a printed circuit board. More specifically, an integrated circuit package assembly may comprise a mounted integrated circuit chip, a block-like multi-apertured element for protecting the package leads, and a heat sink member. The present tool, under operation control, captivates the entire package assembly, ejects the protective block prior to package insertion, positions the assembly on the printed circuit board, and inserts the package leads into homologous apertures of the board--the foregoing requiring minimal, if any, physical contact with the assembly by the operator. | 8 |
This application is a continuation of application Ser. No. 08/457,898, filed Jun. 1, 1995, which is a divisional of Ser. No. 08/330,159 filed Oct. 27, 1994 both now abandoned.
BACKGROUND OF THE INVENTION
A nonwoven fabric is defined as an interlocking fiber network characterized by flexibility, porosity and integrity. The individual fibers used to compose the nonwoven fabric may be synthetic, naturally occurring, or a combination of the two. The individual fibers may be mechanically, chemically, or thermally bonded to each other. Nonwovens are used commercially for a variety of applications including insulation, packaging, household wipes, surgical drapes, medical dressings, and in disposable articles such as diapers, adult incontinent products and sanitary napkins. Tissue is a closely related material in which the individual fibers may or may not be chemically bonded to one another.
In many of the aforementioned applications it is necessary to adhere the nonwoven or tissue to another substrate or component. The second substrate may be another nonwoven, tissue, or an unrelated material. A commonly employed technique to bond the assembly together is the use of a hot melt adhesive. Hot melt adhesives allow for cost and time efficient manufacturing since there is no evaporation step necessary as is the case for water based or solvent based adhesive systems. Suitable hot melt adhesives must possess excellent adhesion to the substrates involved. For nonwoven applications they must also possess good flexibility (or hand), no staining or bleed through, suitable viscosity, set speed and open time to function on commercially available equipment and finally, acceptable thermal aging properties.
Recently a variety of nonwoven and tissue applications have been developed which require that the hot melt adhesive demonstrate the ability to transmit the liquid from the nonwoven substrate into the superabsorbent or fluff core substrates. This property, referred to as strike through, is especially important in disposable diaper, sanitary napkin and bed pad constructions where it is desired to draw the moisture away from the body and into the absorbent core as quickly as possible after the nonwoven is wetted.
SUMMARY OF THE INVENTION
It has now been discovered that the addition of a fluorochemical surfactant to conventional hot melt adhesives increases the hydrophilic character of the hot melt adhesives. When a coating of the resultant hot melt is applied between the coverstock nonwoven and the absorption pad of the disposable product, the hydrophilic character of the hot melt improves the strike through properties of the liquid as compared to conventional hot melt coatings which, more often, serve as a barrier to the liquid transmission.
While various surfactants have been added to hot melt adhesives to reduce their foaming tendencies or to improve adhesion, it was unexpected that the addition of these specific fluorochemical surfactants would not only provide acceptable adhesion levels but would also provide improved strike through without reducing the absorbency speed or capacity of the absorbing material, properties essential for the particular end use applications.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The fluorochemical surface active agents utilized herein are nonionic in character and essentially comprise blends of C 7 and C 8 fluorinated alkyl alkoxylates and fluorinated alkyl sulfonamides. They are present in an amount of 0.1 to about 10 parts, preferably 0.5 to 5 parts, per 100 parts of the adhesive composition. Commercially available surfactants are obtained from 3M Chemical Company, as FLUORAD FC 430, FC 1802 and FC 171. They comprise approximately 86 to 89% C 8 fluorinated alkyl alkoxylate, 9 to 10% C 8 fluorinated alkyl sulfonamide, 2 to 4% C 7 fluorinated alkyl alkoxylate and 0.1 to 1% fluorinated alkyl sulfonamide. These materials are characterized, respectively, by Brookfield viscosities (25° C.) of 7000 cp (spindle #3 @ 6 rpm) and 150 cp (spindle #1 @ 60 rpm); specific gravity @ 25° C. of about 1.1, 1.4 and 1.4.
The fluorochemical surfactant may be added to virtually any hot melt adhesive used in disposable construction applications including, but not limited to, those hot melt adhesive compositions based on ethylene/vinyl acetate copolymers, isotactic or atactic polypropylene, styrene-butadiene, styrene-isoprene, or styrene-ethylene-butylene A-B-A or A-B-A-B block copolymers or mixtures thereof. In addition to the base polymer, these hot melt adhesive compositions generally contain tackifiers, oils and/or waxes as well as conventional additives including stabilizers, anti-oxidants, pigments and the like. Typical of such formulations are those described in U.S. Pat. Nos. 4,460,728 issued Jul. 17, 1984 to R. C. Schmidt, Jr. et al.; 3,492,372 issued Jan. 27, 1970 to T. P. Flanagan; 4,411,954 issued Dec. 6, 1983 to P. P. Puletti et al.; 4,136,699 issued Jan. 30, 1979 to J. A. Collins et al.
In more detail, the fluorchemical surfactant may be added to adhesives based on rubbery block copolymers. These polymers include the block or multi-block copolymers having the general configuration: A-B-A or A-B-A-B-A-B- wherein the polymer blocks A are non-elastomeric polymer blocks which, as homopolymers have glass transition temperatures above 20° C., while the elastomeric polymer blocks B are butadiene or isoprene or butadiene isoprene which is partially or substantially hydrogenated. Further, they may be linear or branched. Typical branched structures contain an elastomeric portion with at least three branches which can radiate out from a central hub or can be otherwise coupled together.
The non-elastomeric blocks which make up 14 to 50% by weight of the block copolymer may comprise homopolymers or copolymers of vinyl monomers such as vinyl arenes, vinyl pyridines, vinyl halides and vinyl carboxylates, as well as acrylic monomers such as acrylonitrile, methacrylonitrile, esters of acrylic acids, etc. Monovinyl aromatic hydrocarbons include particularly those of the benzene series such as styrene, vinyl toluene, vinyl xylene, ethyl vinyl benzene as well as dicyclic monovinyl compounds such as vinyl naphthalene and the like. Other non-elastomeric polymer blocks may be derived from alpha olefins, alkylene oxides, acetals, urethanes, etc. Styrene is preferred.
The elastomeric block component making up the remainder of the copolymer is isoprene or butadiene which may or may not be hydrogenated as taught, for example, in U.S. Pat. No. 3,700,633. This hydrogenation may be either partial or substantially complete. Selected conditions may be employed for example to hydrogenate the elastomeric block while not so modifying the vinyl arene polymer blocks. Other conditions may be chosen to hydrogenate substantially uniformly along the polymer chain, both the elastomeric and non-elastomeric blocks thereof being hydrogenated to practically the same extent, which may be either partial or substantially complete.
Typical of the rubbery block copolymers useful herein are the polystyrene-polybutadiene-polystyrene, polystyrene-polyisoprene-polystyrene and e.g., polystyrene-poly-(ethylenebutylene)-polystyrene and polystyrene-poly-(ethylenepropylene)-polystyrene. These copolymers may be prepared using methods taught, for example, in U.S. Pat. Nos. 3,239,478; 3,427,269; 3,700,633; 3,753,936; and 3,932,327. Alternatively, they may be obtained from Shell Chemical Co. under the trademarks Kraton 1101, 1102, 1107, 1650, 1652 and 1657; from Enichem under the Europrene Sol-T tradenames; and from Firestone under the tradename Stereon 840A.
Other adhesive compositions may be prepared according to the invention using, as a base polymer, amorphous polyolefins or blends thereof. Amorphous polyolefins are made by the stereospecific polymerization of polypropylene. Polymerization occurs in the presence of a catalyst comprising a coordination complex of a transition metal halide with an organometallic compound. The solid amorphous polypropylene has a softening point of about 150° and a viscosity at 190° C. of 1,000 to 4,500 cps. Suitable commercial products include Eastmans P 1010. Copolymers of amorphous polypropylene and ethylene (APE), butene (APB) and hexene (APH) are suitable as a base polymer, as are terpolymrs of propylene, butene and ethylene (APBF). Commercial examples of APE include Rextac 2315 from Rexene, of APB including Rextac 2730 from Rexene and APBE include Vestoplast 750 and 708 from Huls.
Ethylene containing polymers are also commonly used for disposable applications and can be improved by the addition thereto of the fluorchemicals in accordance with the teachings of the invention. Thus ethlylene is polymerized with 15 to 45% by weight of such copolymerizable monomers as vinyl acetate, N-butyl acrylate, propylene, methyl acrylate, methyl acrylic acid, acrylic acid, metallocene catalyzed ethylene based polymers and the like as well as mixtures thereof.
Blends of any of the above base materials, such as blends of ethylene vinyl acetate and atactic polypropylene may also be used to prepare the hot melt adhesive composition. In all cases, the adhesives are formulated with tackifying resins, plasticizers, waxes and/or other conventional additives in varying amounts as are known to those skilled in the art.
The tackifying resins useful in the adhesive compositions can be hydrocarbon resins, synthetic polyterpenes, rosin esters, natural terpenes, and the like. More particularly, and depending upon the particular base polymer, the useful tackifying resins may include any compatible resins or mixtures thereof such as (1) natural and modified rosins such, for example, as gum rosin, wood rosin, talloil rosin, distilled rosin, hydrogenated rosin, dimerized rosin, and polymerized rosin; (2) glycerol and pentaerythritol esters of natural and modified rosins, such, for example as the glycerol ester of pale, wood rosin, the glycerol ester of hydrogenated rosin, the glycerol ester of polymerized rosin, the pentaerythritol ester of hydrogenated rosin, and the phenolic-modified pentaerythritol ester of rosin; (3) copolymers and terpolymers of natured terpenes, e.g., styrene/terpene and alpha methyl styrene/terpene; (4) polyterpene resins having a softening point, as determined by ASTM method E28-58T, of from about 80° to 150° C.; the latter polyterpene resins generally resulting from the polymerization of terpene hydrocarbons, such as the bicyclic monoterpene known as pinene, in the presence of Friedel-Crafts catalysts at moderately low temperatures; also included are the hydrogenated polyterpene resins; (5) phenolic modified terpene resins and hydrogenated derivatives thereof such, for example, as the resin product resulting from the condensation, in an acidic medium, of a bicyclic terpene and a phenol; (6) aliphatic petroleum hydrocarbon resins having a Ball and Ring softening point of from about 70° to 135° C.; the latter resins resulting from the polymerization of monomers consisting of primarily of olefins and diolefins; also included are the hydrogenated aliphatic petroleum hydrocarbon resins; (7) aromatic petroleum hydrocarbon resins and the hydrogenated derivatives thereof; and (8) alicyclic petroleum hydrocarbon resins and the hydrogenated derivatives thereof. Mixtures of two or more of the above described tackifying resins may be required for some formulations.
Various plasticizing or extending oils are also present in the composition in amounts of 5% to about 30%, preferably 5 to 25%, by weight in order to provide wetting action and/or viscosity control. Even higher levels may be used in cases where block copolymer containing hydrogenated mid-block are employed as the adhesive base polymer. The above broadly includes not only the usual plasticizing oils but also contemplates the use of olefin oligomers and low molecular weight polymers as well as vegetable and animal oil and their derivatives. The petroleum derived oils which may be employed are relatively high boiling materials containing only a minor proportion of aromatic hydrocarbons (preferably less than 30% and, more particularly, less than 15% by weight of the oil). Alternatively, the oil may be totally non-aromatic. The oligomers may be polypropylenes, polybutenes, hydrogenated polyisoprene, hydrogenated polybutadiene, or the like having average molecular weights between about 350 and about 10,000. Vegetable and animal oils include glyceryl esters of the usual fatty acids and polymerization products thereof.
Various petroleum derived waxes may also be used in amounts less than about 15% by weight of the composition in order to impart fluidity in the molten condition of the adhesive and flexibility to the set adhesive, and to serve as a wetting agent for bonding cellulosic fibers. The term "petroleum derived wax" includes both paraffin and microcrystalline waxes having melting points within the range of 130° to 225° F. as well as synthetic waxes such as low molecular weight polyethylene or Fisher-Tropsch waxes.
An antioxidant or stabilizer may also be included in the adhesive compositions described herein in amounts of up to about 3% by weight. Among the applicable antioxidants or stabilizers are high molecular weight hindered phenols and multifunctional phenols such as sulfur and phosphorous-containing phenols. Representative hindered phenols include: 1,3,5-trimethyl 2,4,6-tris (3,5-di-tert-butyl-4-hydroxy-benzyl)benzene; pentaerythritol tetrakis-3(3,5-di-tert-butyl-4-hydroxyphenyl)-propionate; n-octadecyl-3,5-di-tert-butyl-4-hydroxyphenol)-propionate; 4,4'-methylenebis (2,6-tert-butylphenol); 4,4'-thiobis (6-tert-butyl-o-cresol); 2,6-di-tertbutylphenol; 6-(4-hydroxyphenoxy)-2,4-bis(n-octyl-thio)-1,3,5-triazine; di-n-octadecyl 3,5-di-tert-butyl-4-hydroxy-benzyl-phosphonate; 2n-octylthio)-ethyl 3,5-di-tert-butyl-4hydroxy-benzoate and sorbitol hexa 3-(3,5-ditert-butyl-4-hydroxyphenyl)-propionate!.
Other additives conventionally used in hot melt adhesives to satisfy different properties and meet specific application requirements also may be added to the adhesive composition of this invention. Such additives include fillers, pigments, flow modifiers, dyestuffs, etc., which may be incorporated in minor or larger amounts into the adhesive formulation, depending on the purpose.
These hot melt adhesives may be prepared using techniques known in the art. Typically, the adhesive compositions are prepared by blending the components in the melt at a temperature of about 100° to 200° C. until a homogeneous blend is obtained, approximately two hours. Various methods of blending are known and any method that produces a homogeneous blend is satisfactory. The resulting adhesives are characterized in that they have a viscosity of 20,000 cP or less at the application temperature of 350° F. (177° C.) or less. The viscosity as used herein is a Brookfield viscosity measured using a Brookfield viscometer model No. DV-II with spindle no. 27 at 10 rpm.
The resulting adhesives of the present invention are characterized by their ability to provide a durable bond to a nonwoven or tissue article and otherwise meet the unique requirements of the application (including flexibility, non-staining, and machinable viscosity). The adhesives described herein also possess exceptional thermal stability which distinguishes them from other moisture sensitive technologies. Further, their hydrophilic natures facilitated ready transmission of the fluid throughout the construction.
The adhesive product can be applied to a substrate such as a nonwoven article or tissue by a variety of methods including coating or spraying in an amount sufficient to cause the article to adhere to another substrate such as tissue, nonwoven, or an unrelated material such as a low density polyolefin or other conventionally employed substrates.
The following examples illustrate the production of suitable hot melt adhesives or binders as well as the use thereof in a variety of applications. In the examples, all parts are by weight and all temperatures in degree Celsius unless otherwise noted. Test procedures used herein are as follows:
TEST PROCEDURES
180° T Peel Testing Procedure
The samples are prepared as follows. A glue line was extruded onto polyethylene (25 micron) at approximately 300° to 325° F. with a line speed of 100 FPM to form a glue line approximately 0.5 mm wide with a coating weight of approximately 0.03 to 0.05 gr/linear meter. A polypropylene nonwoven substrate was immediately bonded to the glue bead with bonding pressure of approximately 60 psi. Samples were then cut parallel to adhesive lines, leaving at least 1/8" on each side of the exterior adhesive lines. The samples were conditioned overnight at 70° F./50% RH constant temperature and humidity. Testing was also done on tissue to tissue samples.
Instron Testing
The ends of each sample were taped, then placed in jaws, with the adhesive coated nonwoven in the stationary jaw. The sample was pulled at 12 in/min crosshead speed, 2 in/min chart speed in 180° T peel mode and the average peel value recorded in grams or pounds for each product tested. If there was bond failure, the type of failure was recorded instead of peel value.
Contact Angle Test
As a drop of liquid meets a solid surface, it assumes a distinctive shape. The shape and length of time that it holds onto its shape are determined by three interfacial tension forces: the force of the solid surface, the surface tension of the liquid and the force at the solid/liquid interface. The contact angle (θ) is a measured value relative to the combined vector forces according to the formula:
y.sub.L COS θ=y.sub.S -y.sub.SL
where y L is the interfacial tension of the liquid/air boundary, y S is the interfacial tension of the solid/air boundary, y SL is the interfacial tension of the solid/liquid boundary, and θ is the angle of the liquid drop.
The goniometer has a microsyringe for dispersing accurate droplet sizes and a camera for photographing the angle of the liquid drop as it meets the surface of the solid. The contact angle is measured as the angle between the substrate and the tangent of the liquid drop (at the interface).
The lower the angle, the more effective the coating is in transmitting the liquid through the adhesive layer.
EXAMPLE 1
The following rubber based hot melt adhesive was prepared and various amounts of FC 1802 (a fluorchemical surfactant from 3M) were added thereto.
______________________________________Parts______________________________________Stereon 840A 23 FirestoneMineral Oil 18 WitcoUnitac R98 Lite 59 Union CampA.O. 0.5 Ciba Giegy______________________________________
Contact angle measurements of the adhesives were made initially, and after 48 hours at 350° F. (177° C.) to determine thermal stability of the FC 1802 in system. The results are shown in Table I.
TABLE I______________________________________CONTROL 2.5% 5.0% 10.0% 20.9%______________________________________INITIAL 77° 62° 27° 27° <17.sup.STABILITYAFTER -- 72° 62° 46° 28°STABILITY______________________________________
The results indicate that after exposure to elevated temperatures for extended periods of time, the presence of the surfactant still presented a noticeably beneficial effect on the coating.
EXAMPLE 2
This example was performed to show the specificity of the fluorchemical surfactant in their effect on the hot melt adhesives. In this case other conventional surfactants were added to the adhesive described in Example 1.
TABLE II______________________________________5 PARTS 5 PARTS 0.3 PARTSPLURONIC F68 IGAPAL CO-890 SILWET L 7607______________________________________INITIAL 80° 70° 82°AFTER 48 74° 74° 74°HOURSAT 350° F.______________________________________ Pluronic F68ethylene oxide propylene oxide block polymerBASF Igapal CO 890nonylphenol ethoxylateRhone Poulenc Silwet L 7607silicone-OSI
The results presented in Table II show that the surfactants tested were not as effective as FC 1802 before or after stability.
EXAMPLE 3
The following example illustrates the use of various levels of the fluorchemical surfactants in the following conventional atactic polypropylene based hot melt adhesive:
TABLE III______________________________________Indopol H100 23 polyisobutylene (Amoco)Vestoplast 750 38 terpolymer of polypropylene/polybutene/ polyethylene (Huls)Eastotac H100 37 partially hydrogenated C.sub.5 (Eastman)A.O. 0.5 hindered phenol______________________________________ CON- TROL 0.1%-FC 171 0.5%-FC 171 1.0%-FC 171______________________________________INITIAL 100° 89° 78° 58°24 HOURS 98° 91° 70° 68°AT 350° F.______________________________________
EXAMPLE 4
The adhesive described in Example 3 was also tested for its bond strength using the 180° peel test. Products were applied at 130° C. at coating weights of 0.03 gr/linear meter and 0.05 gr/linear meter (pattern was a multiline using a Meltex Coater).
TABLE IV______________________________________ STANDARD +0.2% +0.5%GRAM/ APAO SURFACTANT SURFACTANT3 LINES HM (FC 171) (FC 171)______________________________________COATING 0.03 0.05 0.03 0.05 0.03 0.05WEIGHT*INITIAL 104 215 125 230 90 168AFTER 24 100 254 130 270 70 164HOURSAFTER 1 130 180 175 360 115 250MONTH______________________________________ *Grams/Linear Meter
The test results presented in Table IV show bond values adequate at 0.2, 0.5, and 1.0% levels at 24 hours and after 1 month of aging at ambient conditions.
EXAMPLE 5
Another series of tests on the adhesive of Example 3 were performed to determine whether the fluorchemical surfactant and the effect thereof would remain in the adhesive after soaking in water at 35° C. for 11/2 hours.
TABLE V______________________________________ FC 171 0.1% FC 171 0.3% CONTROL______________________________________INITIAL 68° 79° 100°AFTER SOAKING 75° 67° --______________________________________
The results show that the flurochemical surfactant remain effective after repeated dosing of the diaper with synthetic urine.
EXAMPLE 6
In addition to the testing described above, nonwoven substrates coated with 5 mg per square inch of the various adhesives were subjected to standard testing to determine the degree of penetration/absorption of synthetic urine through the coated substrate when the substrate was placed on an inclined surface. The amount of time, in seconds, required for all the liquid to pass through the coated substrate was noted. The results indicate that nonwovens coated with the fluorchemical surfactant containing adhesive exhibited rapid absorption of at least two doses (5 ml each) of the liquid as compared with the same nonwoven substrate which had been coated with standard adhesives. The results are shown in Table VI.
TABLE VI______________________________________ FIRST SECOND THIRD DOSE DOSE DOSE______________________________________APAO BASED CONTROL 3 22 >25APAO BASED +0.5% FC-430 3 12 21RUBBER BASED CONTROL 9 22 21RUBBER BASED +0.5% FC-430 5 9 22______________________________________
These results clearly demonstrate the suitability of the adhesives for nonwoven and other disposable applications. Similar results would be expected using fluorchemical containing adhesives prepared from other polymer bases and/or adhesives containing compatible formulating materials.
In summary, the results show that these hot melt adhesives may be successfully used to form nonwoven disposable product as described hereinabove. It will be apparent that various changes and modifications may be made in the embodiments of the invention described above, without departing from the scope of the invention, as defined in the appended claims, and it is intended therefore, that all matter contained in the foregoing description shall be interpreted as illustrative only and not limitative of the invention. | A method for improving the strike through properties of hot melt adhesive compositions comprising the step of incorporating therein a nonionic fluorchemical surfactant in an amount of 0.1 to 10 parts by weight per 100 parts adhesive. | 3 |
REFERENCE TO PRIOR APPLICATIONS
In my previously filed copending application Ser. No. 526,509 filed Nov. 25, 1974 entitled "INTRAOCULAR LENS," (now abandoned), I have disclosed a lens suitable for placement in the eye following entracapsular extraction. In copending application Ser. No. 547,620 filed Feb. 6, 1975, entitled "INTRAOCULAR LENS FOR INTRACAPSULAR EXTRACTION," (now abandoned), I have disclosed a lens suitable for insertion in the eye following extracapsular extraction. In copending application of Hartstein and Platt Ser. No. 638,610 filed Dec. 8, 1975, entitled "BIFOCAL INTRAOCULAR LENS" (now abandoned) is shown a number of intraocular lens with bifocal portions therein.
BACKGROUND OF THE INVENTION
This invention relates to the art of medicine and has particular reference to artificial lenses employed in ophthalmology for correction of aphakia and restoration of binocular vision.
In the late 1940's Ridley inserted the first intraocular lens into the posterior chamber of the eye. Subsequently, the work of Epstein and Binkhorst was directed toward a lens positioned in the anterior chamber and supported by the iris. The so-called "Iris Clip Lens" has legs aligned on the top and bottom of the iris about 180° from each other and is designed to clip onto the iris. Fedorov U.S. Pat. No. 3,673,616 shows a modification of the iris clip lens involving three posterior loops and three antenna-like extensions in front of the iris. Binkhorst also has developed a lens designed for anchoring to the cleft between the iris and the capsular membrane by iridocapsular adhesions following the extracapsular extraction. Worst had developed a lens having an anchor on the iris at right angles to the posterior legs, which lens is used primarily following intracapsular extraction, although it can be used following extracapsular extraction.
In my copending applications Ser. Nos. 526,509; 547,620; and 638,610, of which I am solo or joint inventor, the intraocular lens shown in said applications all require suturing to the iris by means of a flange with openings therethrough which allows the lens to be sutured to the iris. Similarly Otter U.S. Pat. No. 3,906,551 shows a lens which has a haptic rim with suture openings therein for fixation to the iris. It would be desirable if the lens could be fastened to the iris without suturing as this would allow a simpler implantation and would obviate the possibility that the suture would become dislodged or break loose after implantation.
Other forms of the Otter disclosure show lens anchored by means of clips rather than sutures, but these devices are loosely positioned in the iridectomy and are not stable in the eye in the vertical or horizontal directions.
The invention of application Ser. No. 526,509 is specifically designed to be used after clean extracapsular extraction. In this type procedure the posterior chamber and the capsular membrane are thoroughly cleaned of all cortial material by an aspirator or like device.
The invention of application Ser. No. 547,620 is specifically designed to be used after intracapsular extraction. In this type procedure the entire cataract and the capsular membrane are removed so that the intraocular lens which is implanted must be anchored to the iris.
The invention of application Ser. No. 638,610 is directed to a bifocal intraocular lens which allows the patient both distance and near vision without the wearing of eyeglasses.
In all of these applications the lens is sutured to the superior portion of the iris, and the sphincter muscle, which controls dilation of the pupil, is avoided to make the position of the lens independent of the pupil size.
It is, therefore, the principal object of the present invention to provide an intraocular lens which is inserted and fixedly positioned with respect to the iris of the eye without the necessity for suturing the same. It is a further object of the present invention to provide an intraocular lens which can be used with either extracapsular or intracapsular extraction and which can be inserted into the eye by use of anchor means which are inserted into incisions in the iris and fixed thereto without the use of sutures.
Still another object of the present invention is to provide a sutureless technique for inserting artificial lens into the eye such that the lens will not move with the eye during dilation and contraction of the pupil and will resist being dislodged from a prefixed position in the eye.
These and other objects and advantages will become apparent hereinafter.
SUMMARY OF THE INVENTION
The present invention comprises an intraocular lens for insertion into the eye either following extracapsular or intracapsular extraction, said lens having means for anchoring the same to the iris of the eye without sutures so that the lens will not move when the pupil dilates and contracts and will resist being dislodged from its fixed position in the eye.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a back elevational view of one embodiment of the invention;
FIG. 2 is a side elevational view of the lens shown in FIG. 1;
FIG. 3 is a sectional view taken along lines 3--3 of FIG. 1 with the lens positioned in the eye which is represented diagrammatically;
FIG. 4 is a side elevational view partly in section and partly diagrammatic of a modification of the invention presently in the eye;
FIG. 5 is a back view of the lens of FIG. 4;
FIG. 6 is a back view of a further modification of the invention;
FIG. 7 is a back view of another modification of the invention;
FIG. 8 is a side elevational view partly in section and partly diagrammatic of another modification of the invention showing the lens in place in the eye;
FIG. 9 is a back view of the lens shown in FIG. 8;
FIG. 10 is an enlarged detailed side elevational view of the lens shown in FIG. 8; and
FIG. 11 is an enlarged fragmentary plan view of the lens shown in FIG. 10.
DETAILED DESCRIPTION
FIG. 1 shows a lens 10 having a central lens portion 11 with inferior anterior anchor means 12 integral therewith. The anchor means 12 comprises diverging tabs positioned about 30° from the vertical centerline "A" of the lens 10. The tabs 12 extend rearwardly at an angle of about 10° from the central portion 11 (FIG. 2).
A posterior anchor 13 is secured to the central portion 11 by means of a head 14 positioned in the front face of the central portion 11. The posterior anchor 13 comprises leg portions 16 which are connected at their ends by a bight member 17. The leg portions 16 extend at substantially the same angle with respect to the central portion 11 as to the anterior tabs 12. The inferior portion of the iris 18 is gripped between the anterior anchor means 12 and the posterior anchor means 13 (FIG. 3) so that the sphincter muscle at the internal periphery of the iris is free to move with respect to the lens 10.
The unique superior anchor of this invention is designated by the numeral "20" and comprises the anterior anchor flange 21 which extends outwardly about 2 mm from the lens central portion 11. The flange 21 is slightly convex as shown in FIG. 2 to conform to the curvature of the superior portion 22 of the iris. Secured adjacent to the outer periphery of the flange 21 is a sutureless anchor means 23 which comprises a rearwardly extending anchor leg 24 secured in the flange 21 by a head 25, and a continuous anchor loop which is spaced about 0.6 mm from the rear surface of the flange 21 and has feet portions 26 and 27 extending toward and away from the central portion 11 respectively. The portions 26 and 27 are positioned between the anchor posts 24 and extend away from said posts 24 toward the periphery of the flange 21 and toward the central lens portion 11. Stated another way, the loop feet portions 26 and 27 extend at substantially right angles to a line connecting the posts 24 and extend on both sides of said line. The portions 26 and 27 are designed to be slipped into an incision cut in the superior portion of the iris 22 behind the sphincter muscle. Thus the lens is independent of contraction and dilation of the pupil which is controlled by the sphincter muscle.
The lens 11, the anterior tabs 12 and the flange 21 are all molded in one piece from a plastic such as polymethyl methacrylate. The anchors 13 and 23 are a platinum wire of about 0.15 mm to about 0.2 mm in diameter.
The lens 10 is anchored into the eye merely by the surgeon making a lateral incision in the superior portion of the iris, slipping the anchor 23 in through the incision to position the lens 10 in the iris and then slipping the inferior portion of the iris 18 between the anchors 12 and 16.
The flange 21 extends away from the lens body 11 at an angle of about 10° from the central portion 11 and the loop portions 27 and 27 are substantially parallel to the flange 21 and at the same angle with respect to the central portion 11.
FIGS. 4 and 5 show a modification of the present invention in which the superior anterior and posterior anchors are changed from that shown in FIGS. 1-3.
In FIGS. 4 and 5, the superior anchor means is a pair of opposed anterior tabs 30 positioned at about 30° from the vertical centerline of the central lens portion 11. The tabs 30 are aligned with and opposed to the inferior anterior tabs 12. Extending rearwardly from the outer ends of the tabs 30 are superior posterior anchor means which comprise a rearwardly extending leg 32 retained in the tab 30 by a head 31 and connecting to a figure "8" shaped posterior foot portion 33. Each of the "8" shaped members 33 is designed to be inserted through an incision in the iris behind the sphincter muscle and to retain the lens in the eye independently of dilation and contraction of the pupil. The "8" shaped foot is at the same 10° angle with respect to the lens center 11 as are the anterior tabs 30. The tabs 12 and 30 are molded integrally with the lens body 11 of polymethyl methacrylate plastic. The anchors 31-33 are of platinum wire and are one piece with the foot 33 being formed into substantially the "8" shape by being bent on itself.
FIG. 6 shows a slight modification of the structure of FIGS. 4 and 5 in which the superior anterior tabs 30a are slightly longer than the tabs 30 of FIGS. 4 and 5 and the tabs 30a are positioned at about a l5° angle with respect to the vertical centerline of the lens 11.
FIG. 7 shows another modification of the invention utilizing a one piece molded anterior superior anchor 40 and a superior posterior anchor 41 in the form of a hook having a depending portion 42 bent inwardly toward the central lens 11 and spaced from the anterior anchor 40 about the thickness of the iris. In this application the hook 42 is inserted through an incision in the iris behind the sphincter muscle.
FIGS. 8-11 show a preferred form of the invention in which the entire lens except for the posterior inferior anchor 13 is molded from one piece of plastic, preferably polymethyl methacrylate. This is therefore a self-fixating and self-retaining lens and does not depend on extraneous wire members for fixation in the eye.
The inner surface 11a of the center lens member 11 is dish shaped and concave to assist in forming and finishing. The superior anchors 50 comprise an anterior portion 51 whose centerline is aligned substantially with the centerline of the opposed anterior inferior leg 12. The anterior legs 51 are at about a 30° angle with respect to the vertical center line of the center lens 11. Connected to the tabs 51 and rearwardly depending therefrom are reduced legs 52 connected to dumbbell shaped anchors 53 which are substantially aligned with the axis of the opposed tabs 51. The dumbbell shaped feet 53 are designed to be slipped through incisions in the iris behind the sphincter muscle and to embrace the iris between the foot 53 and the tabs 51 to retain the lens 11 in the eye securely without sutures.
The feet 53 extend toward and away from the central lens portion 11 and preferably are substantially aligned with the centerline of the anterior tabs 51. | An intraocular lens which can be inserted and fixed in the eye by means of retaining members which are positioned in openings in the iris in an essentially sutureless technique. The lens does not move with the pupil during dilation and contraction and resists becoming dislodged or dislocated in the eye. | 0 |
FIELD OF THE INVENTION
[0001] The invention relates to a receptacle for a wheeled frame, in particular for the transportation of babies or infants.
BACKGROUND OF THE INVENTION
[0002] Transportation of infants and babies in bicycle trailers is not readily possible, because the bicycle trailer seats are not designed for this. Due to the lack of suitable solutions for this problem, infant seats designed for use in cars are often placed in bicycle trailers and attached therein with belts. While an infant can, in principle, be transported in a bicycle trailer in such manner, this has the distinct disadvantage that infant car seats are very bulky and generally wider than the area of the seat provided for one child. This is particularly problematic with bicycle trailers with two seats, since once the car seat is placed in the bicycle trailers, there is hardly any room left for a second child, let alone a second infant car seat.
[0003] The only option available on the market for transporting babies in a bicycle trailer is a hard polystyrene infant seat made by the German manufacturer Weber Technik Werkzeugbau GmbH, which contrary to the aforementioned car seats has been tailored to the width of the child seat of a bicycle trailer. This carrier has a concave reclining seat area, the bottom area of which is flattened out opposite the back and shoulder area. It has a passage opening in the center just below the bottom area as well as several pairs of passage openings on both sides of the central vertical axis in the shoulder area for the belts of a restraint system. In addition, there are fastener openings in the upper and lower area of the carrier, through which the belts of a bicycle trailer seat can be threaded in order to attach the carrier.
[0004] This carrier, too, has some distinct disadvantages. It is bulky, which makes fastening the carrier in a bicycle trailer seat difficult and does not allow for space-saving storage, for instance in a warehouse or a garage. The carrier is rigid so that it does not adapt to the position and movement of a baby or infant. Finally, the carrier is not breathable, which is particularly uncomfortable on warm days or when sitting in the carrier for an extended period of time.
SUMMARY OF THE INVENTION
[0005] The basic idea of the invention consists in making the body receptacle from a flexible material which can be brought into the shape necessary for transporting the baby/infant by bracing the material externally and/or within itself, as required. Bracing externally means that there are tensioning devices extending from or outside of the body receptacle that are attached to the frame in such a way that they exert tension on the mat. In this case such tensioning devices can be, for example, lengthwise adjustable belts with springs. Bracing “within itself” means that the tensioning devices find support in the material itself when under tension. Such internal bracing is possible, for example, with spring poles which are inserted into hemmed seams in the mat and inserted—under tension—into the anchoring points of the mat, similar to a self-supporting dome tent.
[0006] The body receptacle according to the invention has a variety of advantages over the baby carrier described above. Thus, when not in use, the flexible mat can be folded and stored compactly after the tensioning devices have been removed. Moreover, even in its transport form, it still has a certain degree of flexibility so that the mat adapts somewhat to a body shape. This makes lying/sitting in the body receptacle more comfortable, as does the fact that the flexible mat can be made partially or totally from breathable material. Finally, attaching the body receptacle in a wheeled frame, in particular in a bicycle trailer, is much easier, at least if it is first attached and then brought into its transport form with the help of tensioning devices.
[0007] In a preferred embodiment of the mat, there are sidewalls in the bottom area, which prevent the infant (infants) from slipping out sideways. The sidewalls work together particularly with a restraint system, which prevent the transported infant (infants) from slipping out of the body receptacle by stabilizing the position of the infant's body.
[0008] In order to increase the comfortableness of the mat, the sidewalls are preferably padded and/or made from an air permeable fabric.
[0009] To stabilize the sides of the body receptacle, there are belts that preferably run lengthwise to the mat. While these belts can in principle be located at the level of the supporting area that supports the underside of the body, it is preferable that they run along the upper edges of the sidewalls. Belts are particularly well suited to stabilize the body receptacle because they can be put under considerable tension. Moreover, the ends of the belts can be fitted with fastening elements, with which the body receptacle can be suspended in a frame or braced therein with the help of tensioning devices.
[0010] The lengthwise-arranged belts can be run through tubular sleeves, which are preferably made from a foamed material, so that the belts are padded. The belts can be attached inside the sleeves, by for example sewing or gluing. The sleeves can be embedded in hemmed seams running lengthwise along the sides of the mat or along the upper edges of the sidewalls.
[0011] The sleeves can be elastic and/or foldable, so that they can be folded or rolled compactly with the mat without causing damage to the sleeve material.
[0012] In addition, the sleeves are preferably curved lengthwise and the mat in its supporting area can be preformed concavely in the working position. A preforming of the mat can, for example, be done by sewing the sidewalls and the supporting area together in such a way that it results in a bottom area that is angled from the back and shoulder area. This makes installing and, in particular, pulling the body receptacle into its transport shape easier.
[0013] In another embodiment, the front edge of the mat is fitted with padding, which is raised with respect to the supporting area. On one hand, this helps stabilize the mat crosswise. On the other hand, the padding provides a safeguard against the baby or infant sliding out, in particular while buckling the child into the mat.
[0014] The stabilization of the mat crosswise to its longitudinal axis is preferably done with the help of a strap fastened to the backside of the mat and running crosswise to its longitudinal axis, the ends of which are fitted with fastening elements. In particular, if this strap is located in the bottom area of the supporting area, it can be used to stretch the body receptacle in such a way that this results in an angle between the bottom area and the back and shoulder area of the supporting area, especially when the mat is braced accordingly at the upper and lower ends of its longitudinal direction. Alternatively, it is also possible to provide a strap at each side of the backside of the mat, with which the mat can be braced towards the back.
[0015] In order to adjust the position of the body receptacle and the forces necessary to brace it, it is helpful if the length of the belts can be adjusted at least at one end.
[0016] In order to make installation easier, at least one of the fastening elements can be constructed as a snap buckle working together with its corresponding counter-piece, which is attached to the frame.
[0017] In order to make sitting or lying in the body receptacle more comfortable, at least some of its surfaces can be fitted with fleece, in particular the padded areas.
[0018] Being particularly durable, it is preferable to use textile fabrics for the mat. In particular, it makes sense to use a textile fabric for the bottom of the mat and, in a preferred further embodiment, to cover it with a layer of foamed plastic for padding. That way, the requirements with respect to both the strength of the material and comfortableness can be met as far as the supporting area is concerned, in particular if the padding is also breathable.
[0019] As a restraint system to keep the baby or infant being transported safe in the event of a bump or collision of the frame, the mat can be fitted with safety belts, which is attached in particular in the stabilized areas of the mat, for example in the areas of the lengthwise or crosswise belts. If the frame is already fitted with a restraint system, the supporting area can have openings for the safety belts of the restraint system. The location of the openings can be the same as with the infant car seats described hereinbefore.
[0020] The above leads to the conclusion that the body receptacle is preferably used in the frame of the passenger compartment of a bicycle trailer.
BRIEF DESCRIPTION OF THE DRAWINGS
[0021] In the following, the invention is described in further detail with the help of two illustrations showing a preferred embodiment of the invention:
[0022] [0022]FIG. 1 is a perspective drawing of a bicycle trailer with a suspended body receptacle; and
[0023] [0023]FIG. 2 is a cross-section of the body receptacle along the line of cross-section II-II in FIG. 1.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0024] The frame of the bicycle trailer shown in FIG. 1 consists of the following main parts: a chassis 1 as well as a passenger compartment located thereon with one part of the frame forming the front and top of the passenger compartment 2 and a passenger compartment rear side 3 . The partial frame 2 has a cross strut 4 located on its front side above the chassis 1 , which is positioned much lower than a cross tube 5 provided at the upper end of the passenger compartment rear side.
[0025] On the chassis 1 , two crossbars arranged in tandem 6 , 7 are provided, to which, among other things, the front and rear edge of a seating area 8 is anchored. Between the rear crossbar 7 and the cross tube 5 provided at the upper edge of the rear of the frame, a rear wall 9 is inserted, which has a padded backrest 11 sewn to its lower part. In the center of the front edge of the seating area 8 , a crotch strap 12 of a restraint system is anchored, which works together with a shoulder belt 14 via a ring 13 , with both ends of the shoulder belt 14 having snap closures 15 , 16 with which they can be attached to the rear wall 9 . The parts of the snap closures 16 located on the rear wall 9 are attached to belts 17 , 18 positioned side by side in such way that their height can be adjusted.
[0026] Between the cross strut 4 and the cross tube 5 , a body receptacle 19 with a mat forming a lying/sitting area 21 is suspended. The body receptacle is held by two belts 22 , 23 running along its sides, the ends of which are looped around the cross strut 4 and the cross tube 5 , respectively, and fastened with buckles 24 , 25 , 26 , 27 . The belts are run through tubular sleeves 28 , 29 made from a foamed material, that form a part of the side walls of the body receptacle and as such provide a safeguard against the baby slipping out.
[0027] The body receptacle 19 is braced with belts 31 , 32 arranged on both sides of the hip area on the backside of the mat 21 , which via closures 33 , 34 work together with belts 35 attached to the rear crossbar 7 .
[0028] By bracing the mat 21 in this manner, it is angled in the hip area so that the bottom area is angled relative to the back and shoulder area and in particular the bottom area is oriented more horizontally than the back and shoulder area.
[0029] Between the tube-like sleeves 28 , 29 and the mat 21 , mesh fabric 37 is sewn in, which is tapered lengthwise towards the upper and lower edge of the infant carrier so that the height of the side walls is increased, in particular in the bottom area.
[0030] In the mat 21 , openings are provided to lead through the safety harness of the restraint system as follows: one opening 38 slightly below the center of the bottom area for the crotch strap 12 including the ring 13 attached thereto, and three pairs of openings 39 , 41 , 42 arranged one above the other in the shoulder area of the mat 21 on both sides of the central longitudinal axis for leading through the shoulder belt 14 .
[0031] At its lower end, mat 21 ends with a crosswise padded roll 40 which safeguards the baby or infant from slipping out of the body receptacle 19 , in particular prior to or while being buckled in.
[0032] The cross-section shown in FIG. 2 shows particularly well that belts 22 , 23 are run through the tubular sleeves 28 , 29 . The bottom side of the mat 21 is made of a textile material 41 in which the tubular sleeves 28 , 29 are sewn in on both sides of mat 21 . Between the tubular sleeves, the top side of the textile material 43 is covered with foamed, breathable padding 44 .
[0033] Many further modifications to the apparatus described and illustrated will readily occur to those skilled in the art to which the invention pertains. The specific embodiments described and illustrated herein should be considered only as illustrated and not be considered limiting of the scope of the claims.
[0034] While the preferred embodiment of the invention has been illustrated and described, it will be appreciated that various changes can be made therein without departing from the spirit and scope of the invention. | A body receptacle for a wheeled frame allows for the transport of babies in a bicycle trailer. The body receptacle has a flexible mat that is brought into the intended transport form with the help of tensioning devices. | 1 |
CROSS REFERENCE TO RELATED APPLICATION
This application is a continuation-in-part of application Ser. No. 410,005, filed on Aug. 20, 1982, abandoned.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention generally involves the hand-knitting of fabrics. More specifically, the invention relates to an improved method of securing, feeding and knitting plural sources of yarn to produce a patterned fabric.
2. Description of the Prior Art
The hand-knitting of fabric having a variegated pattern, such as an argyle or plaid pattern, requires plural sources of different colored or shaded yarns which must be available for continual use as each yarn strand is sequentially incorporated into the fabric during knitting. The knitter must introduce each strand of yarn from its source as each new color is incorporated into the fabric, with this being accomplished in such a manner so as to form no gaps between the colors.
The actual procedure of hand-knitting a patterned fabric requires that the knitter first proceed across a knit row, adding each new color from an appropriate yarn source and with each new yarn strand being brought up from underneath and then passed over the previously used yarn strand as the stitch is made. This latter procedure of "twisting" the yarn provides a firm transition from one color to another. When the knit row is completed and the respective colored yarn strands have been incorporated into the fabric, the knitter must then rotate the knitting needles clockwise so that a purl row can be started working from right to left. Working the purl row, the knitter again brings the new yarn strand up and over the previously worked strand, thereby again completing a twist.
Because of the plurality of yarn sources required in this form of knitting a patterned fabric, the prior art has proposed various devices and accessories to facilitate the manipulation of the yarns so that there will be less tangling than occurs when the sources are left to dangle on bobbins. Some devices require that the individual yarn sources be supported on spools, but this arrangement requires manual unwinding, exposing the yarn sources to soiling, and does nothing to reduce actual tangling of the yarn strands. Another prior art approach involves the disposition of plural yarn balls together in a common, partitioned container, an arrangement which maintains the yarn sources in a clean condition, but nevertheless requires the manipulation of the yarn sources themselves when twists are made during the knitting process. Still another type of known device separates the yarn strands through a comb-like device, but still maintains the yarn sources supported on bobbins disposed below the "comb".
None of the heretofore known prior art devices teach the combination of storing individual yarn sources in separate discrete containers having individual tightly fitting lids, disposing the containers and yarn sources in a linear array in the exact sequence in which they will appear in the knitted fabric, supporting the containers on a common base, and permitting the knitting of a patterned fabric wherein the knitter is not required to handle or manipulate the individual yarn sources during the knitting process. This highly desirable combination of factors serves to render possible the knitting of a patterned fabric in which yarn strands that are twisted on a knit row shall be untwisted on a purl row.
Some examples of the aforedescribed prior art devices for facilitating the hand-knitting of patterned fabrics from plural yarn sources are disclosed by the Geisman U.S. Pat. No. 2,264,664, Sedgewick U.S. Pat. No. 2,493,208, Fitts et al. U.S. Pat. No. 2,628,042, Broschard U.S. Pat. No. 3,054,277 and DePaez et al. U.S. Pat. No. 4,008,806.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide an improved method of facilitating the hand-knitting of patterned fabrics.
It is another object of the invention to provide an improved device and method of knitting a fabric wherein a plurality of different yarn balls of different colors are stored and dispensed in the exact sequence that the colors appear in the finished fabric.
It is a further object of the invention to provide an improved method of storing and dispensing yarn in a method of knitting a patterned fabric from a plurality of individual yarn sources by which the tangling that occurs during the "twisting" of the yarn strands is automatically reversed and untangled without the need for manipulating the yarn sources during knitting.
It is still a further object of the invention to provide an improved device for facilitating the hand-knitting of patterned fabrics wherein the device is simple in construction, easy to use and economical to manufacture.
These and other objects of the invention are achieved through an improved method of hand-knitting a patterned fabric by providing a device for storing and dispensing a plurality of individual yarn balls wherein the device is defined by a plurality of discrete separate containers disposed in a linear array and secured to a common support base. Each container is preferably rectangular or box-shaped and includes a snug fitting removable cover with an aperture through which a yarn strand may be dispensed from a yarn ball freely supported in the container. The container substantially fully encloses the yarn balls contained therein to prevent soiling of the yarn balls and tangling of the individual yarn strands being dispensed. The containers and covers are preferably made of transparent plastic to permit viewing the yarn balls for color and identification and ascertaining the amount of yarn remaining on each ball. It is further preferable that alternate containers be identified, such as by tinting, so that contrasting colored yarns can be disposed in clear containers while background colored yarns are disposed in the tinted containers, thereby affording the knitter with immediate visual orientation of the different yarns. The cover of each container is slidably and tightly fitted onto its associated container, with individual containers being spaced at a sufficient distance from each other to facilitate removing and adding individual yarn balls without disturbing adjacent yarn sources.
Other objects, advantages and aspects of the invention and the various features of construction shall become apparent to those skilled in this art upon reference to the following specification and accompanying drawings forming a part hereof.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view depicting the knitting of a patterned fabric, specifically an argyle sock, according to a preferred embodiment of the present invention;
FIG. 2 is an end view of the device used to practice the invention as shown in FIG. 1;
FIG. 3 is a top view of the device shown in FIG. 2;
FIG. 4 is a sectional view taken along the line 4-4 of FIG. 3; and
FIG. 5 is an exploded perspective view, shown partly in section, of an individual container and its associated cover, of the device shown in FIG. 2.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
A device 1 is shown in FIG. 1 in use by a knitter, indicated generally at 3, in the knitting of a patterned fabric 5 according to a preferred embodiment of the present invention. Fabric 5 may be an argyle sock or similar article. Device 1 is preferably supported in a substantially stationary position on the lap of knitter 3 who performs the knitting process in a seated position in order to facilitate continual and sequential dispensing of a plurality of yarn strands 7 from a plurality of yarn balls 8 contained in device 1.
Yarn balls 8 are of varying colors and shades which collectively determine the final pattern of fabric 5. While device 1 is shown as including provision for storing nine yarn balls 8 and dispensing a corresponding number of yarn strands 7 therefrom, it is understood that device 1 can be expanded or reduced in size in accordance with the teachings set forth herein to store and dispense any number of yarn balls 8, depending upon the nature and type of fabric 5 being kintted.
The details of device 1 shall now be described with particular reference to FIGS. 2 and 3. As seen, device 1 includes a plurality of discrete and separate containers 9, disposed and spaced in a linear array and having their bottoms secured to a support base 11. Each container 9 is of a rectangular box-shaped configuration and provided with an associated cover 13 which is slidably and snugly fitted onto container 9 in a particular manner to be later described. With specific reference to FIG. 3, it is seen that each cover 13 is provided with an aperture 15 for the purpose of dispensing yarn strands 7 therethrough.
It is preferred that device 1, including at least each container 9 and its associated cover 13, be entirely made from transparent plastic material to permit the viewing of individual yarn balls 8 stored in containers 9. As also shown in FIG. 3, by making alternate containers 9 of clear plastic material and remaining containers 9 of tinted plastic material, knitter 3 may orient yarn balls for contrasting colors required in the knitting of fabric 5.
The use of plastic material for making device 1 greatly simplifies the manufacturing process and results in an economical product that is strong, light in weight and easy to manipulate during the knitting process. Should support base 11 be also made of the same plastic material used in making containers 9, containers 9 may then be secured to base 11 through the use of appropriate adhesive or any other technique well known in the art for connecting plastic members together.
The details of container 9 and its associated cover 13 shall now be described with particular reference to FIGS. 4 and 5. Container 9 and cover 13 collectively define a rectangular-shaped box having a smooth exterior surface, with both container and cover 13 sharing an identical transverse cross-sectional configuration. The manner in which cover 13 is removably secured to container 9 is important inasmuch as this engagement must not only be easy to accomplish, but also remain snug against accidental removal of cover 13 during the knitting process. These requirements are realized by providing the outer peripheral surface of container 9 with an inward flange 17 of reduced thickness and an associated outward ledge 19. Similarly, cover 13 is provided around its open peripheral edge with an outward flange 21 of reduced thickness and an associated inward ledge 23. As is therefore apparent, this arrangement permits cover 13 to be slidably fitted onto container 9 until the terminal end of its inward flange 17 engages inward ledge 23 and the terminal end of outward flange 21 engages outward ledge 19. The thickness of inward flange 17 corresponds to the width of inward ledge 23. Similarly, the thickness of outward flange 21 corresponds to the width of outward ledge 19.
As seen in FIG. 4, when cover 13 is fully engaged on container 9, both the interior and exterior wall surfaces of cover 13 and container are in smooth coplanar disposition with respect to each other. This permits freely disposing yarn ball 8 within container 9 without the need of supporting yarn ball 8 on a spool. Accordingly, yarn strand 7 is therefore permitted to be freely dispensed through aperture 15 of cover 13 without tangling in itself or with other yarn strands 7 supported by device 1. The slidable engagement between cover 13 and container 9 has been shown to be snug and secure against accidental removal of cover 13 during the knitting process. However, cover 13 may easily be intentionally removed by knitter 3 when it is desired to change or replenish yarn ball 8.
Device 1 provides an extremely simple and yet effective means for facilitating the hand-knitting of patterned fabric from a plurality of yarn sources in an efficient manner. The minimum weight of device 1 greatly facilitates its manual manipulation. Yarn balls 8 are conveniently stored in device 1 in a manner that permits free dispensing of their respective yarn strands 7 without tangling, notwithstanding the number of yarn strands being dispensed. The construction of device 1 from transparent plastic material, preferably wherein containers 9 and covers 13 are formed from alternating clear and tinted plastic material, facilitates observing the extent of yarn supply remaining as well as providing instant visual orientation of different yarns for contrasting and background colors.
MODE OF OPERATION
A preferred method of practicing the invention for utilizing aforedescribed device 1 shall now be detailed. Knitter 3 first winds the necessary number of colored yarn balls for the fabric to be knitted so that each yarn strand feeds from the inside of its corresponding yarn ball to provide a free and continual flow of yarn. A yarn ball 8 of selected color is then disposed in each container 9 in the same sequence that the selected colors shall ultimately appear in the finished fabric. Individual yarn strands 7 are then drawn through apertures 15 of their corresponding covers 13, after which covers 13 are snugly fitted onto containers 9. Knitter 3 thereafter proceeds with the actual knitting process by first knitting a knit row from yarn strands 7 wherein each succeeding yarn strand 7 is lifted up and over the previous yarn strand 7, thereby twisting same. When the knit row has been completed, knitter 3 then turns the knitted fabric 180° and works a purl row, again lifting each succeeding strand 7 up and over previously used strand 7. This action, accomplished while maintaining device 1 in a substantially stationary position, adjacent to or on the lap of knitter 3, shall automatically cause the untwisting of the yarn strands that were previously twisted on the knit row. As the knitter again prepares to undertake another knit row by returning the knitted fabric 180° to its original position, it shall be apparent that the yarn strands are once again in their original parallel position.
The invention only requires that knitter 3 manipulate yarn strand 7 during the knitting process, without the necessity of manipulating yarn balls 8 since the latter are securely enclosed within their individual containers 9. The only purpose for handling yarn balls 8 by knitter 3 would be to replenish the yarn sources, change the color of a desired pattern or correct a knitting error.
It is to be clearly understood that the embodiments of the invention herein shown and described are to be taken as merely preferred examples of the same, and that various changes in the shapes, sizes, arrangement of parts, compositions and methods of use and operation may be resorted to, without departing from the spirit of the invention or scope of the subjoined claims. | A method whereby patterned fabrics are knitted from plural sources of colored yarn without tangling of the yarn strands or need for repositioning the yarn sources during knitting by providing a yarn source holder for disposing a plurality of yarn balls in a linear array wherein the yarn strands are twisted during the knitting of the knit row and untwisted during the knitting of the purl row while maintaining the holder in a substantially stationary position. | 3 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a method for making an antimicrobial elastomeric material containing an antimicrobial composition such as a dispersion of silver oxide that is suitable for implantation within the body
2. Prior Art
Medical devices, particularly implantable elastomeric prostheses which are used in environments where micro-organisms are actively growing, can become covered with a biofilm comprising a colonized layer of microorganisms such that the function of the prosthesis is impaired. After growth of the biofilm microbial layer, filaments can grow and descend into the body or wall of the prosthesis and detrimentally affect its physical properties until the device no longer functions. The fouled device must be cleaned or discarded.
Whenever a prosthesis is in contact with moisture in a warm, nutrient rich environment, the surfaces of the prosthesis may support microbial growth which may include, inter alia, bacteria. The microbial growth can interfere with the functioning of the prosthesis, requiring removal of the prosthesis for disposal or cleaning. The microbial growth is a persistent problem in the management and care of patients who have had their larynx removed and utilize a voice prosthesis since the prosthesis is exposed to a non-sterile, humid, warm, nutrient rich environment.
Various methods for preventing microbial growth on an indwelling device have been proposed. One approach for reducing bacterial infection encountered with the use of medical devices inserted into body cavities has been to apply an antimicrobial coating to the surface of the medical device. For example, U.S. Pat. No. 4,592,920 to Murtfeldt; U.S. Pat. No. 4,603,152 to Laurin et al and U.S. Pat. No. 4,677,143 to Laurin et al. each teach applying a coating containing an antimicrobial agent such as silver oxide to the outer surfaces of medical devices such as catheters, enteral feeding tubes, endotracheal tubes and other hollow tubular devices. The '920 patent to Murtfeldt is primarily concerned with providing a surface coating of an antimicrobial metal compound on a medical device such as a catheter, but also discloses that the metal compound can be “imbedded” within the entire catheter. However, the Murtfeldt patent teaches that the imbedded construction is less desirable since the antimicrobial metal compound imbedded within the side wall of the catheter has less likelihood of encountering migrating microbes and, by inference, is less effective than a surface coating.
Seder et al., in pending U.S. patent application Ser. No. 09/833,961, the content of which is incorporated herein by reference thereto, teach that antimicrobial agents can be compounded (i.e., embedded) into those portions of a prosthesis that are not in contact with tissue. The antimicrobial portions remain free of microbial growth for an extended period which contributes to longer use of the prosthesis in vivo. For example, the valve in most voice prostheses is not in contact with tissue. It is only in intermittent contact with body fluids. The same is true of the inside surface of the tubular prosthesis and/or the facial and inside surfaces of rings or cartridges that are present to reinforce the soft body of a prosthesis. By adding an amount of microbial agent effective to resist growth onto (or into) the valve, ring or cartridge, it is found that microbial growth is delayed for a significant period without any evidence of irritation or toxicity to the tissue. Seder et al. further teach that the antimicrobial agent-bearing elastomer can be compounded by dispersion of the antimicrobial agent into the raw elastomer material. For example, silicone elastomer can contain at least 10 percent of an antimicrobial agent such as silver, or silver compounds such as silver oxide. Other suitable antimicrobial compounds such as, for example, gold, platinum, copper, zinc metal powder or oxides and salts thereof, can be used in the non-tissue contacting portions of the prosthesis. A more complete discussion of prior art methods for incorporating antimicrobial agents into, or upon, a prosthesis is also presented in Seder et al.
A problem with prior art methods of dispersing an antimicrobial agent such as Ag 2 O into an elastomer prior to forming a prosthetic article therefrom is the short work-time available for forming the elastomer into a prosthesis, or a portion thereof, after compounding; sometimes the work-time being as short as a minute or two. It is, therefore, desirable to provide a method for incorporating an antimicrobial agent such as, for example, silver oxide, into an elastomer such as silicone that provides a longer work-time for fabricating an article therefrom.
SUMMARY
The present invention is directed to an antimicrobial elastomer composition and a method for making the composition that substantially obviates one or more of the limitations of the related art. To achieve these and other advantages and in accordance with the purpose of the invention, as embodied and broadly described herein, the method of making the antimicrobial elastomer of the present invention includes the steps of: (a) presenting a two-part, addition-curable silicone elastomeric dispersion consisting of Part A and Part B; (b) mixing part A with part B to form a liquid, moldable silicone elastomer; (c) dispersing additional inhibitor into the silicone elastomer wherein the inhibitor is any agent that affects the cure time of the liquid elastomer; and (d) compounding an antimicrobial agent into the liquid silicone elastomer. The resulting liquid silicone may be molded to form an article over an extended period of time (i.e., “work-time”). In a second embodiment of the method of the present invention, the mixing of Part A and Part B may be delayed by adding additional inhibitor to one or both parts of the silicone, followed by the addition of the antimicrobial agent to one or both parts of the silicone prior to the step of mixing Part A and Part B.
The features of the invention believed to be novel are set forth with particularity in the appended claims. However the invention itself, both as to organization and method of operation, together with further objects and advantages thereof may be best understood by reference to the following description.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
A first preferred method for making an antimicrobial elastomeric composition in accordance with the present invention comprises the steps of: (a) presenting Part A and Part B of a silicone elastomer wherein when Part A and Part B are mixed together in the presence of an initiator, a curable, injection moldable silicone elastomer is formed; (b) mixing part A with part B to form a liquid, moldable silicone elastomer; (c) dispersing additional inhibitor into the silicone elastomer wherein the inhibitor is any agent that affects the cure time of the liquid elastomer; and (d) compounding an antimicrobial agent into the liquid silicone elastomer.
A second preferrend method for making an antimicrobial elastomeric composition in accordance with the present invention comprises the steps of: (a) presenting Part A and Part B of a silicone elastomer wherein when Part A and Part B are mixed together in the presence of an initiator, a curable, injection moldable silicone elastomer is formed; (b) adding additional inhibitor to Part A or Part B; (c) dispersing particles of an antimicrobial agent in Part A or Part B; and (d) mixing Part A with Part B.
In yet a third preferred method for making an antimicrobial elastomeric composition in accordance with the present invention, the method comprises the steps of (a) presenting Part A and Part B of a silicone elastomer; again wherein when Part A and Part B are mixed together in the presence of an initiator, a curable, injection moldable silicone elastomer is formed; (b) adding additional inhibitor to both Part A and Part B; (c) dispersing particles of an antimicrobial agent in Part A or Part B; and (d) mixing Part A with Part B.
In all of the methods for making an antimicrobial silicone elastomer having an extended work-time in accordance with the present invention, the preferred antimicrobial agent is silver oxide. It is clear to artisans that in order to form an elastomeric article by injection molding, the moldable elastomer comprising the article must be in a physical form operable for conforming to the contour of a mold into which it is injected. The term “work-time”, as used herein, means the length of time after Part A and Part B of a 2-part elastomer composition are admixed that the elastomer composition remains injection moldable at or near room temperature. Part A and Part B are preferably platinum cured and provide a silicone elastomer having a durometer between 40 and 70, and most preferably about 60, when cured. Although the amount of inhibitor incorporated into Part B of a 2-part silicone elastomer by the manufacturer is generally maintained as a trade secret by the manufacturer, it is believed to be on the order of 0.02% w/w as supplied. The term “inhibitor”, as used herein, refers to any substance that, when added to a silicone elastomer comprising a mixture of Part A and Part B, increases or extends the work-time (i.e., the time required for the elastomer to cure). An example of a suitable inhibitor is 2-methyl-3-butyn-2-ol. The amount of additional inhibitor to be added to Part A and/or Part B, either prior to or after mixing, is related to the amount of work-time altering additive such as silver oxide added to the elastomer. The amount of additional inhibitor added to the silicone elastomer in accordance with the method of the present invention is in the range of 0.05-0.40% w/w, and preferably in the range 0.05-0.1% w/w. A preferred mole ratio of additional inhibitor to silver oxide in the silicone elastomer is about 1:40.
EXAMPLES
Example 1
Present 50 grams silicone part A; then
Add 50 grams of silicone part B to part A; then
Add 0.08 ml of inhibitor to the part A/part B mixture to provide a silicone elastomer; then
Disperse additional inhibitor throughout the part A/part B silicone elastomer; then
Add 7.5 grams silver oxide to the inhibitor/silicone elastomer mixture; then
Disperse silver oxide throughout the inhibitor/silicone elastomer mixture.
The work-time of the antimicrobial silicone elastomer thus formed is on the order of several hours to two days
Example 2
Present 50 grams of silicone part B; then
Add 0.12 ml of additional inhibitor to silicone part B; then
Disperse the additional inhibitor throughout part B; then
Add 11.1 grams silver oxide to the inhibitor/part B mixture; then
Disperse the silver oxide throughout inhibitor/part B mixture; then
Add 50 grams silicone part A to inhibitor/silver oxide/part B mixture; then
Disperse silicone part A throughout previous mixture.
Elastomers made in accordance with either Example 1 or Example 2 provide a viscous, injection-moldable antimicrobial composition having a work-time of several hours to two days. For example, an addition cure silicone such as those known as gum-stock silicones could be used in lieu of an injection moldable silicone elastomer, maintaining generally the same chemical makeup and curing mechanism, but providing a different presentation for working with and molding the material. While particular embodiments of the present invention have been illustrated and described, it would be obvious to those skilled in the art that various other changes and modifications can be made without departing from the spirit and scope of the invention. For example, a further method for making an antimicrobial elastomeric composition may comprise the steps of: (a) presenting Part A and Part B of a silicone elastomer wherein when Part A and Part B are mixed together in the presence of an initiator, a curable, injection moldable silicone elastomer is formed; (b) adding additional inhibitor to Part A or Part B; (c) dispersing particles of an antimicrobial agent in Part A and Part B; and (d) mixing Part A with Part B. It is therefore intended to cover in the appended claims all such changes and modifications that are within the scope of this invention. | A method for making an elastomeric material containing an antimicrobial composition such as a dispersion of silver oxide that is suitable for implantation within the body. The elastomer made in accordance with this method extends the amount of work-time available for processing the elastomer into an article as compared with the work-time available when using prior art compounding methods. | 0 |
FIELD OF THE INVENTION
[0001] The present invention relates to the field of food technology and delivery of insoluble or hydrophobic biologically active compounds via beverages and food. In particular the present invention provides isolated casein micelles useful for nanoencapsulation, stabilization and protection of hydrophobic active compounds and methods of producing same.
BACKGROUND OF THE INVENTION
[0002] Casein, which accounts for about 80% of milk protein, is organized in micelles. Casein micelles (CM) are designed by nature to efficiently concentrate, stabilize and transport essential nutrients, mainly calcium and protein, for the neonate (1). All mammals' milk contains casein micelles. Cow's milk contains 30-35 g of protein per liter, of which about 80% is within CM.
[0003] Micelles are spherical colloids, 50-500 nm in diameter (average of 150 μm) (2), made of the main four caseins: α s1 -casein (α s1 -CN), α s2 -CN, β-CN, and κ-CN (molar ratio ˜4:1:4:1 respectively) (1-3). The caseins are held together in the micelle by hydrophobic interactions and by bridging of calcium-phosphate nanoclusters bound to serine-phosphate residues present within the casein molecules (1).
[0004] The structure of the casein micelles is important for their biological activity in the mammary gland as well as for their stability during processing of milk into various products, as well as for the good digestibility of the nutrients comprising the micelles. The micelles are very stable to processing, retaining their basic structural characteristics through most of these processes (1-3).
[0005] However, it has not yet been possible to effectively harness these remarkable natural nanocapsules as nanovehicles for the delivery of added hydrophobic or poorly soluble biologically active compounds.
[0006] Caseinates have been used as microencapsulation wall materials (4). However, caseins forming such artificial capsules have lost the original micellar structure, as well as much of their natural functional behavior (e.g. during enzymatic coagulation of milk for cheese production). Moreover, the generally larger size of microcapsules is more likely to impair products smoothness.
[0007] CM can be re-assembled in vitro, by simulating their formation in the Golgi system of the mammary gland, according to aprocedure developed by Knoop et al (7).
[0008] Vitamin D is a fat-soluble vitamin of great importance in calcium and phosphate metabolism, i.e. in facilitating of calcium absorption in the intestine, transporting calcium and phosphate to the bones, and re-absorption of calcium and phosphate in the kidneys. Vitamin D also takes part in the formation of osteoblasts, in fetal development and in the normal function of the nerve system, the pancreas and the immune system (5).
[0009] The recommended daily intake of vitamin D is 5 μg per day for adults between 21-51 years of age, and 10 μg per day for children and pregnant women. Fortified cereals, eggs, butter and fish oil are all vitamin D sources (5). However, vitamin D, being fat soluble is hardly found in skim milk and low-fat dairy products consumed in large quantities particularly in modern societies, being an important sources for calcium and phosphate.
[0010] Vitamin D has over 40 known metabolites, one of which is vitamin D2. Vitamin D2 originates from plants. It is found in nature in limited amounts, but can be synthesized readily, and therefore it is the main form of vitamin D used in the pharmaceutical industry. The vitamin structure contains double bonds that are sensitive to oxidation. Light, air and high temperature induce vitamin isomerization or degradation into inactive products (5;6).
[0011] Adsorption of hydrophobic nutraceuticals like vitamin D2, onto hydrophobic domains of the caseins, which tend to be found in the core of the micelle, would serve to stabilize these nutraceuticals in aqueous systems, protect them from degradation, and facilitate the enrichment of low fat and fat free dairy and other food products with these bioactive molecules, while minimizing the effect of their incorporation on the functional behavior of the system during processing.
[0012] Certain casein micelles are known in the art. U.S. Pat. No. 5,173,322 relates to the production of reformed casein micelles and to the use of such micelles as a complete or partial replacement for fat in food product formulations. Related U.S. Pat. No. 5,318,793 teaches powdered coffee whitener containing reformed casein micelles. U.S. Pat. No. 5,833,953 teaches a process for the preparation of fluoridated casein micelles, in which at least 100 ppm of a soluble fluoride salt are added to a solution comprising micellar casein.
[0013] U.S. Pat. No. 6,991,823 discloses a process for the preparation of mineral-fortified milk comprising the addition of an amount of a pyrophosphate or orthophosphate to the milk in order to enable the mineral to migrate into the protein micelles. It is to be explicitly understood that the present invention excludes mineral fortification of milk.
[0014] U.S. Pat. No. 6,290,974 teaches a food composition comprising a food additive comprising a preformed complex comprising P-lactoglobulin and a lipophilic nutrient selected from the group consisting of vitamin A, vitamin D, vitamin E, vitamin K 1 , cholesterol, and conjugated linoleic acid. In that disclosure the lipophilic nutrient is bound to β-lactoglobulin via one or more amino acid residues, and in particular in proximity of or at the tryptophan 19 moiety of β-lactoglobulin.
[0015] U.S. Pat. No. 6,652,875 provides a formulation for the delivery of bioactive agents to biological surfaces comprising at least one isolated and purified casein protein or salt thereof in water. That invention relates to particular isolated and purified casein phosphoproteins in the form of casein calcium phosphate complexes intended to remain on the surface of oral cavity tissues or the gastrointestinal tract. There is neither teaching, nor suggestion regarding formation of nanoparticles, nor introduction of the bioactive compounds into nanoparticles.
[0016] US Patent Application Publication No. 2002/0054914 teaches a calcium phosphate/drug core with casein micelles reconstructed as aggregates around the cores, forming micellar structures, for the delivery of pharmaceutical agents. According to that disclosure, casein molecules are arranged, presumably as micelles, around calcium phosphate particles containing the active drug, and are linked to the therapeutic agent-containing microparticles by mainly calcium phosphate and electrostatic bond interactions.
[0017] A paper by the inventor of the present invention published after the priority date of the present application describes introduction of exogenous hydrophobic biologically active compounds, including nutrients, nutraceuticals, drugs etc. into nano-sized casein micelles useful as carriers for such hydrophobic compounds, and in particular as a vehicle for the enrichment of a food or beverage product with a particular insoluble or poorly soluble agents (8). Such vehicles are not disclosed or suggested by the background art. Thus, there remains an unmet need in the food and beverage industry for compositions and methods useful in enhancing the nutritive value of a food or drink.
SUMMARY OF THE INVENTION
[0018] The present invention provides casein micelles as nanocapsular vehicles for hydrophobic biologically active compounds, particularly for nutraceuticals. The present invention departs from the known functions of casein micelles (CM) as a vehicle for minerals or their use as a fat substitute and utilizes reconstructed CM for encapsulation of insoluble or poorly soluble hydrophobic biologically active compounds. Molecules advantageously encapsulated within the CM include molecules having nutritional, therapeutic or cosmetic activity.
[0019] The present invention thus provides for the first time a system based on re-assembled casein micelles (rCM) for the delivery of hydrophobic biologically active compounds in food and beverages. According to certain embodiments, the food and/or beverages are low fat and non-fat. Advantageously, the system comprises only natural, generally regarded as safe (GRAS), non-toxic components.
[0020] The present invention provides a novel approach for the nanoencapsulation and stabilization of hydrophobic biologically active compounds, particularly in non-fat or low fat edible products. The nano-capsules disclosed by the invention can be incorporated into a low-fat or non-fat dairy products or other food or beverage products without adversely modifying its properties. The system of the present invention is useful for encapsulation and delivery of sensitive health-promoting and cosmetic substances using natural, GRAS ingredients. It is to be explicitly understood that the present invention excludes mineral fortification of milk.
[0021] A major unique aspect of this invention is the harnessing of casein micelles for the stabilization, delivery and protection of insoluble and hydrophobic biologically active compounds, particularly nutraceuticals. The fully functional reconstituted CM not only are the ideal vehicles mimicking natural micelles to stabilize and deliver biologically active compounds, but their properties enable their incorporation into milk products without the need to modify any of the product properties or preparation process. Furthermore there is no need for an isolated and purified casein protein. For example, the rCM remain stable in acid or enzymatic curd formation during yoghurt or cheese production. These benefits cannot be guaranteed using other casein-based preparations, which do not maintain the natural structure and properties of casein micelles.
[0022] The present invention is based in part on the surprising finding that vitamin D2 is between about 5 to about 22 fold more concentrated within re-constituted micelles than in the surrounding medium. Moreover, the morphology and average diameter of the re-assembled micelles were similar to those of naturally formed CM. Unexpectedly, the reconstructed or re-assembled CMs (rCM) also provide partial protection against light (e.g. UV-light)-induced degradation of a sensitive compound encapsulated within the CM, as exemplified herein for vitamin D2.
[0023] The present invention thus provides use of CM as nanovehicles for entrapment, protection and delivery of sensitive hydrophobic biologically active compounds, including nutraceuticals, drugs and cosmetic products. Advantageously, the CM of the present invention enables delivery of the hydrophobic biologically active compound via low-fat or non-fat food and beverages, as well as in processed milk products. Thus, according to preferred embodiments, the nanovehicles of CM are used within low-fat and non-fat food and beverage products.
[0024] According to one aspect the present invention provides a re-assembled casein micelle comprising at least one type of an exogenous hydrophobic or poorly water-soluble biologically active compound in the relatively more hydrophobic core of the micelle. In some embodiments the hydrophobic biologically active compound is selected from the group consisting of a drug, a nutraceutical, and a cosmetic compound.
[0025] In one embodiment the hydrophobic biologically active compound is selected from the group consisting of a peptide, a protein, an amino acid, a lipid, a proteoglycan, a polysaccharide, a vitamin, a hormone, a drug, a steroid a phytochemical, a flavorant, a sweetener, an anti-microbial, a preservative and the like.
[0026] According to certain currently preferred embodiments, the biologically active compound is a hydrophobic nutraceutical.
[0027] In some embodiments the nutraceutical is a fat-soluble vitamin. Suitable fat-soluble vitamins include vitamin D (D2, D3 and their derivatives), vitamin E (β, β, γ, δ-tocopherols, or α, β, γ, δ-tocotrienols), vitamin A (retinol, retinal, retinoic acid), vitamin K (K1, K2, K3 and their derivatives). In specific embodiments the vitamin is vitamin D.
[0028] In other embodiments the encapsulated compound is a sterol, cholesterol or its derivatives.
[0029] According to certain embodiments, the hydrophobic biologically active compound or nutraceutical is Coenzyme Q10.
[0030] In other embodiments, the biologically active compound or nutraceutical is selected from a carotenoid including α-, β-, or γ-carotene, lycopene, lutein, zeaxanthin, astaxanthin and others.
[0031] In yet other embodiments the nutraceutical is selected from an unsaturated fatty acid including linoleic acid, conjugated linoleic acid, linolenic acid, omega-3 fatty acids including but not limited to docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) and their glycerol-esters.
[0032] In some embodiments the nutraceutical is selected from phytoestrogens including phytosterols (e.g. β-sitosterol, campesterol, stigmasterol etc.), isoflavones (genistein, daidzein), stilbenes (e.g. trans-resveratrol), lignans (e.g. Matairesinol) and coumestans (e.g. coumestrol), and others.
[0033] In yet other embodiments the nutraceutical is selected from a bioactive peptide, such as casein-phosphopeptide (CPP) and other calcium-binding peptides.
[0034] In some embodiments the casein micelle is about 50 nm to about 500 nm in diameter. In other embodiments the average diameter of the casein micelles is about 100-150 nm.
[0035] In another aspect the present invention provides a composition comprising a re-assembled casein micelle, the micelle comprising a hydrophobic biologically active compound within the relatively hydrophobic core of the micelle.
[0036] In some embodiments the composition is selected from a non-fat or low fat food product or beverage.
[0037] In certain embodiments, the biologically active compound is selected from the group consisting of nutraceuticals, drugs and cosmetic products. According to certain currently preferred embodiments, the biologically active compound is a nutraceutical.
[0038] In yet another aspect the present invention provides a method for the preparation of a re-assembled casein micelle, the micelle comprising at least one hydrophobic or poorly water soluble biologically active compound within the micelle, the method comprising the steps of:
a) preparing an aqueous solution comprising a source of casein; b) adding a cosolvent solution comprising at least one type of hydrophobic biologically active compound to the casein solution; c) adding a source of citrate ions, a source of phosphate ions and a source of calcium ions to the mixture of step (b) to form a nano-sized micelle dispersion; d) adjusting the pH of the dispersion to stabilize the nano-sized micelles.
[0043] According to certain embodiments, step (c) of the method comprises
(i) adding a source of phosphate ions and optionally a source of citrate ions to the mixture of step (b); (ii) preparing a solution of calcium ions; and (iii) combining the mixture of step (i) with the calcium solution of step (ii) under high pressure homogenization.
[0047] In some embodiments the method further comprises the step of drying the micelle dispersion.
[0048] The cosolvent used to prepare the solution comprising at least one hydrophobic compound can be any food grade water miscible organic solvent, which evaporates during the drying of the micelles. Natural or synthetic solvents as are known in the art can be used according to the teaching of the present invention. In some embodiments the solvent is ethanol.
[0049] In some embodiments the source of casein is sodium caseinate. In other embodiments the source of casein is milk, or milk powder, or any soluble caseinate or casein preparation, or isolated alpha, beta, and/or kappa casein or mixtures of such caseins.
[0050] In some embodiments the source of citrate ions is provided as tri-potassium citrate, or tri-sodium citrate or any food-grade citrate salt, preferably a source of citrate that is derived from milk or any other natural food source.
[0051] In some embodiments the source of phosphate ions is provided as K 2 HPO 4 or Na 2 HPO 4 or any food-grade phosphate salt. In some embodiments the phosphate source derives from milk or any other natural food source.
[0052] In certain embodiments the source of calcium ions is provided as CaCl 2 , CaF 2 , or calcium citrate, or any food-grade calcium salt, preferably calcium salt derived from milk or any other natural food source.
[0053] In some embodiments the solution comprising casein comprises about 1% to about 20% caseinate, typically 3-8%, more typically 4%-6% casein in an aqueous solution. The aqueous solution may also contain a food grade organic solvent.
[0054] In some embodiments the pH is adjusted to a pH in the range of about 6 to about 7.5, preferably in the range of about pH 6.5 to about 7.0.
[0055] In an optional embodiment the dispersion of step d) is dried to produce a water-dispersible dry product. Suitable methods of drying a dispersion include freeze-drying, spray-drying, drum-drying or any other method known to one with skill in the art.
[0056] Further embodiments and the full scope of applicability of the present invention will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.
BRIEF DESCRIPTION OF THE FIGURES
[0057] FIGS. 1A-1B presents RP-HPLC chromatograms of vitamin D2 in (A) centrifugation-pellets of rCM and of D2-rCM, and in (B) supernatants of rCM and of D2-rCM FIGS. 2A-2C shows size distributions of (A) rCM, (B) D2-rCM and (C) naturally occurring CM in skim milk.
[0058] FIGS. 3A-3C presents Cryo-TEM images of (A) rCM, (B) D2-rCM and (C) naturally occurring CM in skim milk. The Bar on the bottom right is 100 nm long. (The dark area on the bottom is the perforated carbon film holding the sample.)
[0059] FIG. 4 shows the size distribution of vitamin D-containing CM prepared by ultra-high pressure homogenization immediately following in-line blending of vitamin D-containing caseinate solution and a calcium solution.
[0060] FIG. 5 presents absorbance spectra of 2.5% caseinate and 31.5 μM Vitamin D2 solutions in the range of 210-360 nm. Dashed line Caseinate; Solid line—Vitamin D2. The vertical line at 254 nm marks the wavelength of the UV lamp used during the exposure experiments.
[0061] FIG. 6 shows a cryo-TEM image of CM encapsulating vitamin D 2 reassembled using ultra high pressure homogenization.
DETAILED DESCRIPTION OF THE INVENTION
[0062] The present invention provides isolated casein micelles and methods for encapsulation of hydrophobic or poorly water-soluble biologically active compounds in CM, with minimal changes to the functional properties of both the micelles and the active compound.
[0063] The present invention now discloses that adsorption of hydrophobic biologically active compounds, for example nutraceuticals, onto the hydrophobic domains of caseins, and the reformation of the micelles stabilize the hydrophobic compound in aqueous surrounding and protect them from degradation. Such casein micelles-hydrophobic compound system facilitates the enrichment of low fat and fat free dairy and other food products with the bioactive molecules, while minimizing the effect of the compound incorporation on the food properties in general and during processing. Encapsulation of biologically active compounds within casein micelles is advantageous over hitherto known encapsulation methods as the micelles are a natural component of milk products and their nanometric size minimizes their effect on the food product, including dairy as well as non dairy foods. In addition, when the active compound possesses undesirable attributes, the encapsulation in the micelles diminishes such unwanted features (e.g. in the case of omega 3 fatty acids). Another important potential benefit is the improved bioavailability of the enclosed compound due to its distribution, at a molecular level, over a very large surface area of the caseins in the nanoscopic micelles, and the fact that caseins are evolutionally optimized for ease of digestion and absorption. The open tertiary molecular structure of casein also facilitates effective proteolysis.
[0064] Specific embodiments include a method for incorporation of vitamin D2 into CM, and evaluation of the encapsulation process by: (a) evaluation of the efficiency of encapsulation, i.e. the percent of added vitamin D2 which was incorporated into the micelles, (b) preservation of micelle properties: diameter as determined by dynamic light scattering (DLS) and morphology (as determined by cryo-TEM), (c) evaluation of the protective effect of the micelles over vitamin D2 from photochemical degradation induced by UV exposure.
Definitions
[0065] For convenience and clarity certain terms employed in the specification, examples and claims are described herein.
[0066] As used herein, the term “casein” refers to the predominant protein in non-human mammals and human milk, comprising the subgroups α s1 , α s2 , β and κ.
[0067] The term “biologically active compound” encompasses a compound having a therapeutic, nutritional and/or cosmetic activity. Biologically active compounds according to the teaching of the invention include, but are not limited to peptides, proteins, amino acids, lipids, proteoglycans, polysaccharides, vitamins, hormones, drugs, steroids, phytochemicals, polynucleotides, flavorants, sweeteners, an anti-microbials, and preservatives.
[0068] A “nutraceutical”, also known as a functional food (or its component), is generally any one of a class of dietary supplements, vitamins, minerals, herbs, healing or disease-preventative foods that have medical or pharmaceutical effects on the body. Exemplary non-polar or hydrophobic nutraceuticals include, but are not limited to fatty acids (e.g., omega-3 fatty acids, DHA and EPA); fruit and vegetable extracts; vitamins A, D, E and K; phospholipids, e.g. phosphatidyl-serine; certain proteoglycans such as chondroitin; certain amino acids (e.g., iso-leucine, leucine, methionine, phenylanine, tryptophan, and valine); various food additives, various phytonutrients, for example lycopene, lutein and zeaxanthin; certain antioxidants; plant oils; and fish and marine animal oils and algae oils. It is to be understood that certain nutraceuticals can be also referred to as therapeutics as well as cosmetic compounds.
[0069] The following examples are presented in order to more fully illustrate some embodiments of the invention. They should, in no way be construed, however, as limiting the broad scope of the invention. One skilled in the art can readily devise many variations and modifications of the principles disclosed herein without departing from the scope of the invention.
EXAMPLES
Materials
[0070] Sodium caseinate (Miprodan 30, 93.5% protein, MD foods ingredients amba, Videbaek, Denmark). Vitamin D2 (Sigma-Aldrich, Rehovot, Israel). Ethanol (absolute), hydrochloric acid (concentrated), (Bio-Lab, Jerusalem, Israel). Tripotassium citrate, sodium hydroxide, (Merck, Darmstadt, Germany). Calcium chloride (Carlo Erba, Rodano, Italy). Dipotassium hydrogen phosphate (Spectrum, Calif., USA).
[0071] Materials for analysis only: petroleum ether and diethyl ether (Bio-Lab, Jerusalem, Israel). Potassium hydroxide and pyrogallol (Merck, Darmstadt, Germany). Ethylene diamine tetraacetic acid (EDTA) (Acros, N.J., USA). Methanol and acetonitrile (both HPLC grade) (Lab Scan, Dublin, Ireland).
Methods
[0072] Non covalent binding of vitamin D2 to sodium caseinate was achieved by dropwise addition of 1-100 mM, typically 2-50 mM, more typically 5-20 mM, more typically 15 mM solution of the vitamin in absolute ethanol into a 1-20% caseinate, typically 3-8%, more typically 5% caseinate solution, while stirring, to a final concentration of about 5-50,000 μM, typically about 10-5000 μM, more typically about 25-1000, more typically 25-100, more typically about 65 μM.
[0073] Re-assembly of CM. Preparation of re-assembled CM (rCM) was done based on the method described by Knoop et al. (8). However, unlike Knoop et al. the casein is provided as a rehydrated commercial sodium caseinate powder, rather than a freshly prepared caseinate, in order to extend the commercial applicability of the method. To 2-10%, more typically 5% non-enriched caseinate solution and to vitamin D2 enriched caseinate solution (200 mL each), 0.5-1.5M, more typically 1 M tri-potassium citrate (4 mL), 0.05-0.5M, more typically 0.2 M K 2 HPO 4 (24 mL) and 0.05-0.5M, more typically 0.2 M CaCl 2 (20 μL) were added. Eight consecutive additions of the K 2 HPO 4 solution (2.5 mL) and of the CaCi 2 (5 mL) were performed, at 15-minute intervals. During this process, samples were stirred in a thermostated bath at 25-42° C., more typically 37° C. The pH was maintained between 6.5-7.0, more typically between 6.7-7.0, using 0.1N HCl or 1N NaOH. The volume was then adjusted to 400 mL with water, the pH was corrected to 6.5-7.0, more typically to 6.7, and the final dispersions were stirred moderately for one hour (8;9).
[0074] Alternatively, phosphate and optionally also citrate are added to the aqueous casein solution containing the hydrophobic molecule and the mixture is blended to make solution A. For example, this solution contains 400 mL 5% sodium caseinate, 2 mL 5 mg/mL vitamin D2 in absolute ethanol, 88 mL 0.4M K2HPO4 and 10 mL 0.8M sodium citrate. A calcium ion source solution (B) is prepared separately. The calcium solution comprises, for example, 300 mL 0.08M CaCl2. Solutions A and B are then combined during a high pressure homogenization process. Ultra-high pressure homogenization may be done by any method known in the art. For example, ultra-high pressure homogenization is performed using a Micro DeBee ultra high pressure homogenizer, at 20-25 kPSI, using a 0.1 mm orifice and 1 mm reactor cylinders, without back pressure, at a temperature of ˜40° C. Flow rates are adjusted so that the main stream (solution A) and the added stream (B) are processed simultaneously throughout the process.
[0075] Analytical fractionation: Micelle preparations were centrifuged at 20° C. and 25,000×g for one hour and the supernatant was separated from the pellet by decantation. The supernatant was then ultra-filtered using Amicon 8050 stirred ultrafiltration cell with a 10,000 Da nominal molecular weight limit membrane (Millipore). All fractions were collected and analyzed for vitamin D2 content.
[0076] Evaluation of micelle protection against UV light induced degradation of Vitamin D2: Samples containing vitamin D2-enriched rCM (D2-rCM) were placed in a wooden light-proof cabinet, and exposed to a 254 nm UV light, at 200 μW/cm 2 intensity for 3, 6, 12, and 24 hours. At each exposure time, three 20 mL samples were compared: a micelle dispersion preparation, a negative control (an identical sample covered with an aluminum foil to completely block the UV), and another control containing only serum from the D2-rCM preparation, which was exposed to UV. The serum samples were obtained by centrifuging D2-rCM dispersion and collecting the supernatant.
[0077] UV spectra determination for caseinate and vitamin D2. Samples of caseinate and vitamin D2 at concentrations similar to their concentrations in the rCM suspension (2.5% and 31.75 μM respectively) were prepared. UV absorbance spectra of the samples were analyzed by absorbance scan at wavelengths between 220 μm and 360 nm, using a Pharmacia Biotech Ultrospec 3000 spectrophotometer.
[0078] Saponification and extraction: Pellets were resuspended in a 100 mM EDTA solution of same weight as the removed supernatant, and equilibrated for 6 hours at 4° C. Both pellet, serum and permeate from each sample underwent saponification and extraction procedures based on Renken and Warthesen (10): Five mL of each sample were placed into a 25 mL glass stoppered round bottom flask wrapped with aluminum-foil. 3 mL of 5% KOH and 1.5 mL of 1% ethanol pyrogallol solutions were added. The samples were flushed with nitrogen, capped and then left to stir slowly in the dark for 12 hours at room temperature.
[0079] Each sample was then poured into a separatory funnel. The round bottomed flask was washed with 2 mL of water, then 0.75 mL of ethanol, and lastly 5 mL of petroleum ether: diethyl ether (90:10 v/v), adding each wash liquid into the separatory funnel. The mixture was gently mixed and the phases were allowed to separate. The hydrophilic phase was then poured into a second separatory funnel adding 0.75 mL ethanol and 5 mL of the ether mixture. After gentle mixing the phases were allowed to separate. The hydrophobic phase was put into the first separatory funnel. 4.5 mL water was used to wash the hydrophobic phase four times (10). The hydrophobic phase was collected and the solvents were evaporated using nitrogen. The dried sample was re-suspended in 1 mL solution of methanol:water (93:7 v/v) (11).
[0080] Determination of vitamin D2 content: Vitamin D2 analysis was done by reverse phase HPLC (RP-HPLC). All samples were analyzed for vitamin D2 using a 4.6×100 mm C18-C2 RP-HPLC column and a UV detector at 265 nm. The gradient used was zero to 75% acetonitrile as eluent B, while methanol:water (93:7 v/v) serve as eluent A (11). Calibration curve was prepared using vitamin D2 standard in methanol:water (93:7 v/v) solution at 7 concentrations ranging from 5 to 250 μg/mL.
[0081] Vitamin D2 fractions were collected during RP-HPLC and analyzed for UV absorbance spectrum from 220 nm to 360 nm for further identity validation, using a Pharmacia Biotech Ultrospec 3000 spectrophotometer.
[0082] Size and morphology determination of rCM: For both rCM and D2-rCM, average size was measured by dynamic light scattering (DLS) (BIC 90Plus, Brookhaven Instruments Corp.). Morphology was determined using Cryogenic Transmission Electron Microscopy (Cryo-TEM): Specimens were prepared in a controlled environment vitrification system (CEVS) at controlled temperature and humidity to avoid loss of volatiles. The samples were brought to a desired temperature (25° C. and 35° C.) and allowed to equilibrate in the CEVS for an hour. Then, a 7 μl drop of the examined dispersion was placed on a TEM copper grid covered with a perforated carbon film, and blotted with a filter paper to form a thin liquid film of the sample (100-200 nm thick). The thinned sample was immediately plunged into liquid ethane at its freezing temperature (−183° C.) to form a vitrified specimen, and then transferred to liquid nitrogen (−196° C.) for storage until examination. The vitrified specimens were examined in a Philips CM120 transmission electron microscope operating at an accelerating voltage of 120 kV. An Oxford CT3500 cryo-specimen holder was used to maintain the vitrified specimens below −175° C. during sample transfer and observation. Specimens were recorded digitally on a cooled Gatan MultiScan 791 CCD camera using the Digital Micrograph 3.1 software, in the low-dose imaging mode to minimize beam exposure and electron-beam radiation damage. Brightness and contrast adjustments were done using Photoshop 7.0 ME.
[0083] Durability of the micelles to high shear Samples of rCM and D2-rCM suspensions, as well as a sample of skim milk reconstituted from powder, were homogenized using a Micro DeBee ultra high pressure homogenizer, by 1 pass at the single-reversed-flow mode at 185±10 MPa, using a 0.1 mm orifice, and a back-pressure of 10±3 MPa. Average diameter of rCM and D2-rCM was measured before and after homogenization process by DLS (see method details above). Relative average diameter changes were then determined for each sample.
Analyses
[0084] FIG. 1 presents the results of the analysis of vitamin D2 in preparations of micelles enriched with vitamin D2 (D2-rCM) and control rCM preparations without the vitamin. Both analyses of the micelle pellets obtained by centrifugation and of their respective serum fractions are presented. In the chromatograms of the control rCM preparation fractions (pellet— FIG. 1A , and serum— FIG. 1B ) vitamin D2 peaks were absent, while in both D2-rCM fractions those peaks were observed. UV absorbance spectra of the peaks identified as vitamin D2 indicated good matching between vitamin D2 standard and vitamin D2 eluted at the same position in the sample runs.
[0085] During the analysis, 45-95%, more typically 65-85% of total vitamin D2 added were recovered by the extraction procedure from the serum and the pellet together. 25-75%, more typically 45-60% of the recovered vitamin D2 were found to be incorporated into the micelles, which accounted for 2-15%, more typically 8% by weight of the total D2-rCM suspension prepared.
[0086] It was determined that vitamin D2 concentration in the rCM was about 2-22 times, more typically 5-10 times greater than its concentration in serum: 44-57 μg/mL vs. 2-8 μg/mL respectively. Therefore, fortification of milk using such vitamin D2-enriched rCM accounting for only 0.001-1%, more typically 0.1-1%, more typically 0.5-0.6% of the total milk casein, would provide about one third of the vitamin D2 recommended daily allowance (RDA) for adults in a single glass of milk (200 mL).
Size and Morphology Determination of rCM
[0087] The re-assembled micelles had average diameters of 146 and 152 nm without and with vitamin D2 respectively ( FIG. 2 ). As mentioned hereinabove, the normal size range of CM in milk is 50-500 nm, and the average is ˜150 nm.
[0088] D2-rCM and rCM had similar morphology, which was also typical to naturally occurring CM, as may be judged by the available resolution of the TEM micrographs ( FIG. 3 ). These micrographs suggest that the incorporation of vitamin D2 has minimal effect over the morphology of the CM.
Shear Stability of rCM and D2-rCM
[0089] Following an ultra-high-pressure homogenization process the average diameter of rCM was reduced to 122 nm (26% reduction) and that of D2-rCM was reduced to 125 ml (27% reduction). The reference micelles from reconstituted skim milk showed a 9% reduction in diameter during the homogenization. While this shows that the reformed micelles are expectedly somewhat weaker than the original micelles, their durability through such extreme shear suggests they could well withstand typical processing shear which is seldom that high. The similar extent of reduction in size for rCM and D2-rCM suggests that the incorporation of vitamin D2 into rCM did not weaken their structure as reflected by shear stability.
Ultra-High Pressure Homogenization Used for Preparation of rCM
[0090] FIG. 4 shows the size distribution of CM obtained by in-line merging of two streams, just before the high pressure chamber of a high-pressure homogenizer. One stream was the aqueous casein solution containing the hydrophobic molecule(s), as well as phosphate and optionally also citrate, and the other stream was a calcium ion source solution. The average size of the CM obtained was 100 mm. FIG. 6 shows a cryo-TEM image of the vitamin D2-containing CM obtained this way. Analysis of vitamin D2 in the micelle-pellet and supernatant of the centrifuged micelle preparation showed 4-5 times higher vitamin concentration in the micelle pellet compared to the supernatant (serum). The pellet contained 30.3±0.4 and the supernatant contained 6.7±0.7 micrograms/mL of the vitamin.
Quantification of the Protective Effect of the Micelles Against UV Light-Induced Photochemical Degradation of Vitamin D2
[0091] Table 1 presents vitamin D2 degradation as the remaining percent of the initial concentration in each fraction with exposure time, in D2-rCM suspension exposed to UV light, D2-rCM suspension unexposed to UV light (control I) and in D2-rCM suspension serum exposed to UV light (control II). (UD=undetectable).
[0000]
TABLE 1
Percent of vitamin D2 remaining in micelle preparation following UV exposure
UV exposed micelle
Unexposed micelle suspension
UV exposed
Exposure Time
suspension
(control I)
serum
(Hrs).
Micelle pellet
Serum
Micelle pellet
Serum
(control II)
0
100
100
100
100
100
3
20.9
7.2
107.8
43.1
0.11
6
2.7
1.7
41.0
74.9
UD
12
2.7
0.5
78.5
77.1
UD
24
1.8
0.9
135.1
62.0
UD
[0092] The data in Table 1 merits several observations: First, the comparison of the UV exposed serum (control II) to the serum of control I (unexposed) shows how relatively quickly photochemical degradation of unprotected vitamin D2 occurs. The vitamin in the serum is presumably bound to residual soluble casein molecules which did not aggregate into micelles. The main interesting observation is the comparison of the rate of degradation of the vitamin within the micelles in the exposed preparation to that of the UV exposed serum (control II). This comparison demonstrates the significant relative protection conferred by the micelles to the encapsulated vitamin. The micelles also confer some protection to the vitamin in their surrounding serum, as the rate of degradation in the serum of the exposed micelle dispersion was lower than that in the exposed micelle-free serum (control II). This may be explained by a “shade” effect of the micelles which block and absorb much of the light. Lastly, it is observed that the degradation of the vitamin in the micelles of the unexposed preparation of control I (although slightly obscured by experimental error) was slower than in the serum of this preparation. This degradation may be due to chemical oxidation, (e.g. by dissolved oxygen) and this observation suggests that the micelles confer some protection against chemical degradation as well, however this remains to be verified by other experiments.
[0093] The nature of the protective effect of the micelles against photo-degradation of the vitamin was examined by comparing the absorbance spectra for both caseinate and vitamin D2 components in the rCM suspension
[0094] As is shown in FIG. 5 , at the concentrations examined for each of the fractions (caseinate and vitamin D2) in the rCM suspension, caseinate, being a protein with aromatic side groups and double-bonds, absorbs significantly more UV light than vitamin D2. These data support the conclusion that casein micelles have protective effect for the vitamin D2 enclosed therein and to some degree also to vitamin D2 around the micelles.
[0095] Casein micelles were shown to be potential nano-vehicles for added nutraceuticals such as the fat-soluble vitamin D2 chosen here as a model. In terms of encapsulation efficiency, about 25% to about 75%, more typically 45-60% of the vitamin retrieved from the micelle suspension was found in the reformed micelles—which contained about 2 to about 22 fold, more typically 4-10 fold higher concentration of the vitamin compared to the surrounding medium. Some vitamin D may be lost by binding to hydrophobic domains of unaggregated proteins in the serum. The extraction-based analysis method allowed the retrieval of about 45 to about 95%, more typically 65-85% of the added vitamin. The micelles' morphology and size were similar to those of naturally occurring CM, in accord with the purpose to minimize modification of micelle properties. It was also shown that apart from their effectiveness in stabilizing oil-soluble compounds in aqueous environment, the rCM have an additional protective affect against photochemical degradation of the entrapped hydrophobic compound, for example the nutraceutical vitamin D2.
[0096] The foregoing description of the specific embodiments will so fully reveal the general nature of the invention that others can, by applying current knowledge, readily modify and/or adapt for various applications such specific embodiments without undue experimentation and without departing from the generic concept, and, therefore, such adaptations and modifications should and are intended to be comprehended within the meaning and range of equivalents of the disclosed embodiments. It is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation. The means, materials, and steps for carrying out various disclosed functions may take a variety of alternative forms without departing from the invention.
REFERENCES
[0000]
1. DeKruif, C. G.; Holt, C. Casein micelle structure, function and interactions. In Advanced Dairy Chemistry -1 Proteins Part A; 3 Fox, P F; McSweeney, P. L. H., Eds.; Kluwer Academic/Plenum Publishers: New York, 2005; 233-276.
2. Fox, P. F. Milk proteins: general and historical aspects. In Advanced Dairy Chemistry -1 Proteins Part A; 3 Fox, P F; McSweeney, P. L. H., Eds.; Kluwer Academic/Plenum Publishers: New York, 2005; 1-48.
3. Swaisgood, H. E. Chemistry of the caseins. In Advanced Dairy Chemistry -1 Proteins Part A; 3 Fox, P F; McSweeney, P. L. H., Eds.; Kluwer Academic/Plenum Publishers New York, 2003; 139-202.
4. Hogan, S. A.; McNamee, B. F.; O'Riordan, E. D.; O'Sullivan, M. Microencapsulating Properties of Sodium Caseinate. Journal of Agricultural and Food Chemistry 2001, 49, 1934-1938.
5. Eitenmiller, R. R.; Landen, W. O., Jr. Vitamin D. In Vitamin analysis for the health and food science ; CRC Press: Boca Raton, 1999; 77-82.
6. Bell, A. B. The chemistry of the vitamins D. In Vitamin D ; Lawson, D E M, Ed.; Academic Press London, 2005; 1-41.
7. Knoop, A. M.; Knoop, E.; Wiechen, A. Sub-structure of synthetic casein micelles. Journal of Dairy Research 1979; 46, 347-350.
8. Semo, E.; Kesselman, E.; Danino, D.; Livney, Y. D. Casein micelle as a natural nano-capsular vehicle for nutraceuticals. Food Hydrocolloids 2007; 21, 936-942.
9 Aoki, T.; Tanaka, H.; Kako, Y. Incorporation of individual casein constituents into micelles in artificial casein micelles. Nippon Chikusan Gakkaiho 1989; 60, 583-589.
10. Renken, S. A.; Warthesen, J. J. Vitamin D stability in milk. Journal of Food Science 1993; 58, 552-6, 566.
11. Mattila, P.; Konko, K.; Eurola, M.; Pihlava, J. M.; Astola, J.; Vahteristo, L.; Hietaniemi, V.; Kumpulainen, J.; Valtonen, M.; Piironen, V. Contents of vitamins, mineral elements, and some phenolic compounds in cultivated mushrooms. Journal of agricultural and food chemistry 2001; 49, 2343-2348. | The present invention relates to the field of food technology and delivery of hydrophobic biologically active compounds, particularly nutrients, via food products and beverages. In particular the present invention provides isolated casein micelles useful for the encapsulation of hydrophobic nutrients, therapeutic and cosmetic compounds, compositions thereof and methods of preparing the micelles. | 0 |
THE FIELD OF INVENTION
The invention relates to a fixing mechanism for a tool for treatment of a material, such as machining, wherein the fixing mechanism comprises a combination of a tool, its frame and tool holder in the frame of a machine tool.
The fixing mechanism according to the invention can be applied in a wide range of technology, including machining by chipping, such as milling, reaming, drilling, turning, etc. of wood, plastics, metal, etc. as the material for machining. The fixing mechanism can be used in various types of robot applications for production, in the exchange of grippers or the like in other automatic devices, such as apparatus for transfer and treatment of pieces, in pneumatic tools, etc., wherein exchange of tools required for different kinds of operations is necessary for carrying out various operations.
Further, the above fixing mechanism for a tool is particularly advantageous for use in cutting, punching, moulding and forming work, particularly in machining of metal sheets in so-called sheet machining centers.
In machining of this kind, the direction of fixing a tool is a linear movement whereby the machining or forming blade edge directs the machining force to the sheet, usually in a direction perpendicular to the main direction of the sheet, the sheet being placed between the tool and its counterpart, i.e. a cushion. The tool-fixing mechanism according to the invention can be used for fixing both the actual machining tool and its counterpart, i.e. the so-called cushion, to the tool holder in the frame of the machine tool.
BACKGROUND OF THE INVENTION
According to prior art, it is common to use a so-called conic fit, i.e. a Morse conic fit, for fixing a tool, whereby the tool frame and the tool holder are joined to each other by a fixing movement in their axial direction, the release being effected in a corresponding manner in the axial direction. In particular, the conic fit has the disadvantage that the connecting surfaces very easily tend to be clamped too much against each other, particularly under effect of axial forces. For this reason, many systems presently in use comprise special release mechanisms for releasing clamped conic surfaces in connection with the exchange of a tool. As a natural result, the costs of fixing mechanisms required by tool settings are increased, also, the mechanisms are relatively complex and therefore subject to disturbances during the actual machining operation and particularly during the exchange of a tool.
SUMMARY OF THE INVENTION
As to the prior art, reference is further made to the publications DE-4218142, EP-22796 and DE-4223158, which disclose tool-fixing mechanisms using interfaces with totally curved surfaces.
It is an aim of the present invention to provide an improved fixing mechanism for a tool, wherein the purpose of the invention is to improve the prior art in the field for a wide range of applications. For achieving these aims, the tool-fixing mechanism of the invention is primarily characterized in that at least one of the connecting surfaces in the tool frame and in the tool holder in the frame of the machining tool, extending mainly in the mounting direction, is shaped as a curved surface and that the first contact surface in connection with the tool frame and the second contact surface in the tool holder are adjusted to be placed against each other in the operational position of the fixing mechanism, in order to transmit machining force between the tool frame and the tool holder. Using the solution presented above, a very simple and secure fixing mechanism is achieved. The tool and its frame can be placed in the tool holder by a very simple movement defined by the curved surface, wherein the connecting surfaces are placed substantially against each other and the contact surfaces, extending in a direction substantially perpendicular to the mounting direction, in the final mounting phase transmit the machining force in the mounting direction between the tool, the tool frame and the tool holder and/or transmit the machining force by means of a frictional contact in a direction substantially perpendicular to the mounting direction.
Some advantageous embodiments of the fixing mechanism according to the invention are presented in the appended dependent claims.
BRIEF DESCRIPTION OF THE FIGURES
In the following description, the invention will be disclosed with reference to series of figures shown in the appended drawings and illustrating some advantageous embodiments of the fixing mechanism according to the invention. In the drawings,
FIG. 1a shows parts of the tool according to the first embodiment, separate in a cross-sectional view in the mounting direction at the beginning of fixing the tool,
FIG. 1b is a cross-sectional view in the mounting direction, showing the stage of mounting the tool and its frame in connection with the tool holder in the frame of the machine tool,
FIG. 1c is also a cross-sectional view in the mounting direction, showing the tool, the tool frame, and the tool holder in the frame of the machine tool in the functional position of the fixing mechanism,
FIG. 1d shows the stage of releasing the tool and the tool frame in the above-mentioned sectional view,
FIGS. 2a-d show another embodiment of the fixing mechanism, corresponding to the stages shown in FIGS. 1a-d, and
FIGS. 3a-c show essential stages of FIGS. 1a-d of a third embodiment of the invention.
DETAILED DESCRIPTION OF THE INVENTION
With reference to FIGS. 1ato 1d, the fixing mechanism comprises as main parts a tool 1, a tool frame 2 for fixing the tool 1, as well as a bushing-like tool holder 3 and clamps 3a. In this embodiment, the tool 1 is a cushion or the like, used as a counterpart for a cutting, punching, molding or forming blade.
A connecting element 4 in the tool frame 2 is an inlay with a cylindrical shape. It comprises a first connecting surface 5 extending substantially in the mounting direction and being a straight line in the mounting direction (arrow A), and further a first contact surface 6, i.e. a bottom surface, joining the first connecting surface and being substantially perpendicular to the mounting direction. In the present embodiment, the first contact surface 6 is in a ring-like flange part extending from the first connecting surface 5, from its end facing the bottom of the connecting element 4, towards the center line K of the fixing mechanism, wherein, as shown in FIG. 1c, the central openings KR 2 and KR 3 of both the tool frame 2 and the holder 3 are equal in size and concentric, making any movements of additional parts possible inside the holder 3, in the mounting direction.
In the first embodiment illustrated in FIGS. 1a to 1d, the curvilinear connecting surface, particularly a spherical surface, is a second connecting surface 7 in connection with the tool holder 3, extending from a ring-like second contact surface, i.e. a front surface, in a direction perpendicular to the mounting direction A and forming part of the outer surface of the tool holder 3, preferably in the mounting direction. With particular reference to FIG. 1c, the tool frame 2 is arranged to surround the second connecting surface 7 in the end of the tool holder 3, the first 6 and second 8 contact surfaces being against each other.
According to the invention, it is advantageous to design the curvilinear surface, i.e. the second connecting surface 7, in a manner that the distance between the radius of curvature r of the curvilinear surface and the center k located on the center line K of the tool holder 3 in the mounting direction and the contact surface, i.e. in the present embodiment the second contact surface 8, fulfills the formula:
r.sup.2 =D.sup.2 +d.sup.2,
wherein
r=the radius of curvature,
D=the radius of the second contact surface 8 perpendicular to the mounting direction A, and
d=the distance between the center of the radius of curvature and the second contact surface in the mounting direction A.
Consequently, a curvilinear second connecting surface 7 is formed, extending from the outer edge of the second contact surface 8 at a distance e from the second contact surface in the mounting direction A, being essentially equal to:
e=2*d,
wherein
d=the distance between the center of the radius of curvature and the second contact surface 8 in the mounting direction A.
To make the fixing mechanism function in a compatible manner, the diameter H of the inlay of the connecting element 4 is substantially H=2*r, preferably H=2*r+Δ, wherein Δ is the fit used and wherein r is said radius of curvature.
It is obvious that both the cross-sectional form of the tool holder 3 at least by the second connecting surface 7 and the cross-sectional form of the connecting element 4 in the tool frame 2 in a direction perpendicular to the mounting direction A, is a circular form. The used fit Δ can be a clearance fit, an interference fit or a pinch fit according to the use of the tool.
FIG. 1b shows the mounting of the tool and its frame 1, 2 in the tool holder 3, wherein the tool frame 2 is moved in an inclined position in relation to the mounting direction A, one edge of the tool holder 3 passing the second connecting surface 7 and drawing the tool frame 2 towards the tool holder 3 by means of clamps 3a fixed in connection with the frame 2 (e.g. groove-nose joint 10a, 10b). The rod-like clamps 3a are thus brought to pass the contact surface 8 in order to fix the groove-nose joint 10a, 10b(FIG. 1a). The tool frame 2 can thus be revolved along the connecting surface 7 forming a spherical curved surface to the position shown in FIG. 1c, where the first contact surface 6 and the second contact surface 8 are in contact with and against each other, ready to receive forces in the mounting direction, the clamp 3a effecting a pressure force between the surfaces 6 and 8, wherein also loads (e.g. torsion) in a direction perpendicular to the mounting direction can be transmitted due to a frictional contact, i.e.
F.sub.R =μ*F.sub.K,
wherein
F R =the radial force,
μ=the friction coefficient effective between the surfaces 6 and 8, and
F K =the tractive force of the clamp 3a.
As shown in FIG. 1 d, the tool frame 2 is released in reverse order by a propulsive force F K by the clamps 3a. It should be noted that in the present embodiment, the depth s of the inlay of the connecting element 4 in the mounting direction A, i.e. the distance between the first contact surface 6 and the ring-like end surface 9 of the tool frame 2, is substantially 2*d, wherein d is the distance between the center K of the radius of curvature r and the second contact surface 8 in the mounting direction A.
The clamps 3a, being two or more clamps surrounding the outer periphery of the tool frame 2, comprise a nose 10b provided at their ends and extending in the radial direction towards the tool frame 2. A groove 10a is provided on the outer surface of the frame 2 of the tool 13, surrounding the same and functioning as a mounting element, and having two radial surfaces 11a and 11b, each being in co-operation with the respective radial surfaces 12a and 12b of each nose 10b during mounting of the tool, when it is fixed (11a and 12a in FIGS. 1 a-c) as well as during release (11b and 12b in FIG. 1 d).
Alternatively, with reference to FIG. 2, the fixing mechanism according to the invention can be arranged so that a curvilinear surface, seen in a direction perpendicular to the mounting direction, is formed on the outer surface of the tool frame 2, which is spherical substantially in the mounting direction, wherein the connecting element 4 in the tool holder is a corresponding inlay. Naturally, it is possible to shape both connecting surfaces at least partly curved.
In the embodiment of FIG. 2, the tool frame 2 comprises a tool fixing element 2a, the tool 1 being fixed on the first surface of the same. The second surface of the plate-like fixing element 2a forms partly the first contact surface 6, against which, in turn, a connecting surface element 2b is fixed, whose surface in the mounting direction forms the curved connecting surface 7. The connecting surface element 2b is placed centrally in relation to the first contact surface 6, wherein the connecting surface element 2b is surrounded by the first contact surface 6 in a ring-like manner. In the mounting direction A, a mounting element 13 extends from the connecting surface element, comprising a central arm 13a substantially in the mounting direction, and an extension element 13b at its free end.
The tool holder 3 is at its end provided with a flange-like extension, its end surface forming the second contact surface 8. The tool holder 3 is like a bushing, wherein a clamp 3a is arranged to be movable inside the bushing hole in the mounting direction, receiving a guiding effect from the internal hole of the bushing form of the tool holder 3. The free end of the clamp 3a is provided with an opening-groove system 14, with an opening 14a arranged in the mounting direction to receive the arm 13a of the mounting element 13 as shown in FIG. 2a, wherein the clamp 3a is in the outer position, and the end of the opening-groove system 14 protrudes in the mounting direction A outside the second contact surface 8, wherein the mounting element 13 of the frame 2 can be mounted e.g. from the side in connection with the groove-opening system 14 so that its extension element 13b is placed inside a groove element 14b. The groove element 14b comprises radial surfaces 12a, 12b at the ends of the groove element 14b, perpendicular to the mounting direction A. Thus, according to FIG. 2b, the tool 1 with its frame 2 can be attracted towards the tool holder 3, wherein the connecting surface element 2b is placed inside the bushing form of the holder 3, the inner surface of the same near the end forming thus the second connecting surface 5. The first radial surface 11a of the extension element 13b is at the mounting stage in contact with the first radial surface 12a of the groove element 14. The mounting is effected in a manner presented in connection with blank 1, resulting in a situation shown in FIG. 2c, where in the fixing shown in FIG. 2c, the clamp 3a is driven by a force F K directed upwards, the contact surfaces 6 and 8 being against each other. The tool 1 is released from the holder in a manner shown in FIG. 2d, wherein the second radial surfaces 11b and 12b of elements 13 and 14 are against each other and the force of the clamp 3a effective in the mounting direction removes the contact surface element 2 from the bushing form of the clamp 3a substantially in the mounting direction A.
With reference to FIG. 3, the frame 2 is fixed to the clamp 3a by means of a ball mechanism 15 or the like placed in the radial direction inside a series of openings 3b in the clamp 3a, wherein at the starting and releasing stages, shown in FIGS. 3a and 3c, the balls 15a or the like can be placed in inlays 16 in the bushing hole of the holder, being thus moved outwards in the radial direction and making it possible for the extension element 13b of the mounting element 13 to pass the balls 15a in the mounting direction A. In the bushing hole of the holder 3, a bushing-like tube forming the clamp 3a is arranged to be movable in the mounting direction A, wherein the mounting of the frame 2 can be started directly according to FIG. 3a by inserting the mounting element 13, including the arm element 13a and the extension element 13b, in the mounting direction A inside the tube form of the clamp 3a, the balls 15a being in connection with the inlays 16 and thus in their outermost position in the plane of the inner surface of the tube form. When the clamp 3a is moved upwards in relation to the holder 3, as shown in FIG. 3b, the balls 15a are placed inside in a direction perpendicular to the mounting direction A and forced in connection with the radial surface 11a of the extension element 13b by the surface of the inner hole of the holder 3, in order to lock and effect the force F K to the frame 2 in a manner corresponding to that explained above in connection with FIGS. 1 and 2. The frame 2 is released as shown in FIG. 3c by using the face surface 3c of the clamp 3a (corresponding to the radial surface 12b in FIG. 2) to push the contact surface 6 of the connecting surface element 2b which thus forms the second radial surface 11b. The connecting surface 5 in the holder 3 is formed in the connecting element 4 which has a diameter exceeding the bushing hole of the holder 3 where the clamp 3a is movable. Consequently in the embodiment according to FIG. 3, the structure corresponding to the groove-opening system 14 (FIG. 2) is formed to be adjusted in the radial direction according to the movement of the clamp 3a, instead of the solid structure of FIG. 2. | The invention relates to a fixing mechanism for a tool for treatment of a material, such as machining. The fixing mechanism comprises a combination of a tool (1), its frame (2) and tool holder (3) in the frame of a machine tool. At least one of the connecting surfaces (r, 7) in the tool frame (2) and in the tool holder (3) in the frame of the machining tool, extending mainly in the mounting direction, is shaped as a curved surface. The first contact surface (6) in connection with the tool frame (2) and the second contact surface (8) in the tool holder (3) are adjusted substantially in a direction perpendicular to the mounting direction, to be placed against each other in the operational position of the fixing mechanism, in order to transmit machining force between the tool frame (2) and the tool holder (3). | 8 |
BACKGROUND OF THE INVENTION
This invention relates to bifold door closures which are counterbalanced in weight and will remain open at any given position. More specifically, this invention relates to bifold door closures which occupy a minimum of space when in the fully open position and which are counterbalanced in weight so as to remain open in any given position and which may be opened without the use of tracks, springs, levers or other complicated mechanisms. Furthermore, this invention is related to a bifold closure which, when opened, will not sag or bind thereby allowing a complete bifolding of one section over another.
Door closures of various types, especially for large openings, are well known in the art, but all have their attending disadvantages. For example, closures used in airplane hangars, warehouses, garages and the like often raise overhead by means of a tracking system and are heavy and cumbersome to operate and/or require a torsion spring, counterweight or other mechanism to offset the weight of the door while being raised. Moreover, these doors occupy considerable space, often swing with a large arc or radius, and are not, in general, capable of being opened and balanced at any given position. These doors also usually open inwardly. Some doors are sectionalized so that, by a system of rollers on a track, they can be angled around a 90° curve in the tracking system. The mechanism for opening and closing these doors is such that the door is not balanced in any given position, and hence, will usually close by its own weight when brought to a certain partially closed position.
Another typical type of closure for large doors is a solid structure wherein the bottom swings outwardly and upwardly and the top swings backwardly in an arcuate pattern. These doors are heavy and when left open there is nothing to offset their weight and so have a tendency to easily sag and warp.
Other types of closures are known such as horizontally opening doors of either an accordian type or doors which either swing inwardly or outwardly or are bifold in equal sections. Such horizontally opening doors usually require considerable space thereby lessening the width of the opening that can be utilized for ingress or egress.
OBJECTS AND BRIEF DESCRIPTION OF THE INVENTION
It is an object of the present invention to provide a weighted and balanced bifold closure which is capable of being fully opened with a minimum of energy and which occupies a minimum of space in the open position.
It is also an object of this invention to provide a bifold closure which is balanced in any partial or fully opened position and which can be opened or closed either manually or electrically with a minimum of effort.
It is a further object of this invention to provide a bifold closure which may be closed and locked in stationary position by the inertia developed during closing and which is self sealing against weather or other outside elements.
It is an additional object of this invention to provide a bifold door which may be fully opened with minimal energy without the use of tracks, springs, levers or other complicated mechanisms.
A still further object of this invention is to provide a bifold door closure which may extend horizontally across the entire length or width of a building thereby allowing substantially one side of the building to be completely opened.
These and other objects of the invention may be accomplished by means of a novel vertically opening bifold door closure consisting of two unequal rectangular sections. The door closure may be custom made to fit any desired opening and may extend across the entire width or length of a building, if desired. The closure consists of two unequal rectangular sections, the smaller upper section of which is pivotally attached along one side to the framework or beam at the top of the opening to be closed and the larger section is pivotally attached to the opposite side of the upper section in an opposite pivotal direction so that when the closure is raised the top section will, for example, swing 90° and the lower section will swing upwardly and fold under the upper section being pivoted through a 180° angle relative to the upper section. The upper section is connected to the framework or beam at the top of the closure opening by means of hinges or other suitable means and comprises about one-fourth of the closure. In the same manner, the upper and lower sections are pivotally connected to each other by means of hinges or other suitable means and the lower section comprises about three-fourths of the closure.
The upper and lower sections both contain sealing means to provide against intrusion of weather or other elements when the bifold closure is in a closed position. The closure also contains a closing mechanism which will maintain the closure in a closed rigid locked position.
The closure may be opened by means of a series of cables connected to the lower section, about one-third of the way from the top of said section, which cables pass through a pulley or series of pulleys to a winch having the same or different predetermined diameter; also connected to and wound about a different portion of the winch is a counterweight, the weight of which may be varied to compensate for the weight of the closure to be opened. The number of connecting cables to the lower section and the number of pulleys utilized will be dependent upon the width of the door to be opened. For doors that are extremely wide it will be obvious that the closures may be broken up into sections and each section opened independently of the other sections.
If desired, the winch may be driven in either direction by an electric motor having the appropriate horsepower.
It is often desirable to utilize a closure that will occupy as little space as possible when in the open position to allow for the maximum freedom of movement around the open space created by opening the closure. Such examples are in warehouses, docking areas, airplane hangars, food storage buildings and the like. When driving or maneuvering a truck or airplane into such a building it is necessary that the door not only open to its maximum ability, but also not interfere with the intended operations inside the building. For example, in an airplane hangar it may be desirable or necessary for the use of the airplane to nearly touch the closure.
It is often necessary, as has been previously stated, that the open space be substantially the width of the building which leaves little or no room for tracking mechanisms, levers, springs, and the like at the side of the door.
The novel features of this invention both as to the manner of construction or organization as well as the operation will be better understood with reference to the following description and drawings. It is to be understood, however, that the descriptions and drawings are for the purpose of illustration only, and are not intended to be a definition as to the scope of this invention.
DRAWINGS OF THE INVENTION
In the drawings:
FIG. 1 is a front elevational view of a bifold door in a locked position the upper section of which, when opened, will move in an outward direction and the lower section will fold inwardly thereunder.
FIG. 2 is a back elevational view of FIG. 1 showing the cables and pulley system winch and the counterweight utilized in opening the door.
FIG. 3 is a sectional front elevational view of FIG. 1 showing the door in a partially elevated position.
FIG. 4 is a side cross-sectional view of FIG. 3 showing the door in a partially open position taken along 4--4.
FIG. 5 is a corner sectional perspective view of one proposed arrangement of electrically opening and closing the bifold door.
FIG. 5a is a partial top sectional view taken along lines 5a--5a of FIG. 5 showing the counterweight containing adjustable weights and its accompanying tracking mechanism.
FIG. 6 is a partial break-away view of the locking mechanism holding the bifold portion of the door taken at line 6--6 of FIG. 2.
FIG. 7 is a perspective break-away view of the portion of the door shown at lines 7--7 of FIG. 2 showing the locking device at the bottom of the bifold door and the means for actuating and releasing said lock.
FIG. 8 is a perspective front elevational view of a bifold door in a locked position, the upper section of which, when opened, will move in an inward direction and the lower section will fold outwardly thereunder.
FIG. 9 is a cut-away side elevational view of an outwardly opening bifold door such as shown in FIG. 8 showing the door in a fully open position and further showing one possible remote positioning of the winch and counterweight.
FIG. 10 is a partial sectional view taken along lines 10--10 in FIG. 8 showing one particular aspect of the cable and pulley system for opening the bifold closure as illustrated in FIG. 8.
FIG. 11 is a side cross-sectional view of FIG. 4 being enlarged, and showing the lower portion of the door being weighted and the door in a closed position with the weight of the closed door being off center to allow the door to spring partially open when latching means are removed.
DETAILED DESCRIPTION
Referring now to the drawings:
There is shown in FIGS. 1 through 5 a complete operative embodiment of the bifold door closure. The closure designated generally as 10 in FIG. 1 consists of an upper rectangular section 11 and a lower larger rectangular section 12. The upper rectangular section is attached along the top longitudinal side to the frame or a beam by hinge means 13. As shown in FIG. 2 the lower section of the door 12 is hingedly attached to the upper section by hinge means 14. Hinge means 14 is attached so as to pivot oppositely from hinge means 13. The lower closure section 12 is connected to a series of cables illustrated in FIG. 2 as 15a, 15b and 15c, which are interconnected by pulley means 16a, 16b and 16c. The pulleys are mounted on the beam or framework above the bifold closure as illustrated in FIG. 2 and further illustrated in FIGS. 4 and 5. Cable 15a passes over pulleys 16a and 16b and is connected to cables 15b and 15c by clamp 18 to form one cable designated as 15d. Cable 15b passes around pulley 16b and cable 15c passes in an opposite direction over the top of pulley 16c and then around the underside of pulley 16b. Cables 15b and 15c are clamped, spliced, interwoven or otherwise connected, along with cable 15a, to form a single cable 15d, such point of attachment is illustrated in FIG. 2 as clamp 18. Cable 15d is then connected to the door raising portion 17a of winch 17. In order not to bind with each other or to become intertwined, cables 15a, 15b and 15c are separated by a cable dividing knife 19, which is attached to the framework adjacent to pulleys 16b and 16c and passes outwardly and then upwardly in a vertical direction to pass between cables 15a, 15b, 15c and 15d to keep them from becoming wound or interwined about each other.
Thus, cable 15d is wound on winch 17a when the winch is revolved in a clockwise direction as illustrated in FIGS. 2, 4 and 5. It will be noted, especially from FIG. 4, that cables 15a, 15b and 15c are connected to lower section of the door 12 in such a manner that the cables will be pulled upwardly in a substantially vertical direction and not at an angle. In general, the upper section 11 will comprise about one-fourth of the vertical height of the bifold closure and the lower section will be about three-fourths of the vertical height. The cables will be attached to the lower section 12 about one-third of the way from the top of said section. In other words, the point of attachment of the cables to section 12 is about one-half way down from the top of the vertical bifold closure. As illustrated in FIGS. 1-4, the upper section of the door connected at hinge 13 will rise upwardly and outwardly, whereas, the lower section of the door 12 connected at hinge 14 to the upper section of the door 13 will rise upwardly and inwardly, and when raised to a completely upright or open position, section 12 will underlie section 11 in a parallel relationship. Thus the thickness 11 and 12 will be the only space taken up in the closure opening. It is readily seen that the door can be simply opened without resorting to complicated tracks, bars, levers, springs, or other mechanisms which limit the usable space around the opening of a conventional hangar, garage or storage shed type door.
As best illustrated in FIGS. 2, 5 and 5a, the door is balanced by means of a counterweight 20 connected by attaching means 21 to a cable 22 through pulley 23 and wraps around winch 17 at position 17b. As the door is raised counterweight 20 is lowered and is maintained in place by means of tracks 24.
In theory, the weight of the counterweight 20 is related to the diameters of winch portions 17a and 17b. If the diameters are the same the counterweight would be the same as the weight of the door. If the diameter of the counterweight portion of winch 17b is twice the diameter of the door cable winding portion 17a then the counterweight 20 need be only one-half the weight of the bifold door but cable 22 must travel twice as far as cable 15d. In actual practice counterweight 20 should be slightly lighter than the weight of the door.
As shown in FIG. 5a the counterweight may open at the top and contain removable objects 25 such as stones, nuts and bolts, metal balls and the like by which the weight of the counterweight may be adjusted. As illustrated in the drawings, as the door is raised winch 17 rotates such that the cable 15d is wound on winch 17a and counterweight cable 22 is unwound from winch portion 17b. As discussed, counterweight 20 is weighted such that the upward pressure exerted by cable 15a, 15b and 15c in lifting the door will be equal to the downward force exhibited by counterweight 20 so that when upward movement of the door is stopped in any open position, the door will remain balanced and remain in that position.
Thus far the opening and closing of the door has referred to a manual operation, however, there is illustrated in FIGS. 2, 4 and 5 electrical means whereby the door may be electrically opened and closed. As best illustrated in FIG. 5, this consists of a motor mounting framework 26 to which is attached a motor 27 having a pulley 28 attached to the drive shaft thereof. Said pulley is connected by a belt 29, to a larger pulley 30 which serves as a speed reduction means for the rotation of shaft 31 upon which is mounted sprocket wheel 32. Larger sprocket wheel 33 is fixedly mounted at the end of winch 17 and is interconnected with sprocket wheel 32 by means of chain 34.
The diameters of pulleys 28 and 30 and sprocket wheels 32 and 33 are sized such that the proper speed reduction takes place when operating motor 27 to allow cable 15d to be wound around drum 17a and to allow the counterweight 20 to be lowered and cable 22 to be unwound from drum 17b. By adjusting the size of the various pulleys and sprocket wheels the maximum amount of force can be applied with the minimum amount of energy utilization.
It is a particular advantage of the present invention that only minimal energy is required to raise and lower the bifold door. For example, motors in the range of from about one-eighth to one horsepower are sufficient to raise and lower a warehouse or airplane hangar door.
In one embodiment of the invention, shaft 31 contains a threaded extension 31a which is connected to levers 35 and 36 which operate limit switches 37 and 38. The hand switch which actuates the limit switches is not shown.
The locking mechanism of the bifold door and the manner in which the door is opened and closed may be interrelated. Sections 11 and 12, when fully closed and locked, are positioned in relation to lifting cables 15a, 15b and 15c such that the weight is off center at hinge 14 as shown in FIG. 11, and will have a natural tendency to pivot at their point of attachment so that the door will spring slightly open as shown by the dashed lines in FIG. 11, when the locking mechanism is released. Such a movement makes it possible for cables 15a, 15b, and 15c which are connected to lower door section 12 by connecting means 59 as shown in FIG. 11, to be raised vertically and sections 11 and 12 to be folded upwardly eliminating the possiblity of sections 11 and 12 being pulled upwardly against each other without pivoting.
To open the door the hand switch is flipped to the up position but limit switch 37 prevents the motor from starting until the locking mechanism has been released and the door has moved slightly open as shown in FIG. 11. With the door slightly ajar the motor will start winding cable 15d on winch portion 17a and unwinding cable 22 from winch portion 17b lowering counterweight 20. As the winch rotates shaft 31a will also rotate and levers 35 and 36 will move in the same direction depending on whether the threads on extension 31a are right handed or left handed. The rotation of extension 31a through levers 35 and 36 move the levers sufficiently that when the door is in a fully upright position limit switch 38 turns the motor off. To close the door the hand switch is turned to the down position reversing the direction in which the motor will turn. As noted in FIG. 5 the limit switches 37 and 38 are connected to the motor by lines 39 and 40. As the door is lowered shafts 31a turns in the opposite direction and levers 35 and 36 also move in the opposite direction until the door is in a substantially closed position at which time the limit switch 38 deactivates the motor and the inertia of the moving door causes it to shut and lock. If desired, and to allow sufficient momentum to the door to shut and lock, the bottom of the door may be weighted by a weight 60 as shown in FIG. 11. The total weight of the door and counterweight, however, are substantially the same as previously discussed.
Although the counterweight, motor and winch have been illustrated as being off to the side of the door, such means could be mounted in any other position relative to the door. For example, they could be mounted overhead above the door if there was sufficient room, or outside the building immediately adjacent the door. It is also obvious that by extending the length of the cables the motor and counterweight could be mounted at the back of the room or space wherein the bifold door serves as the front closure.
It is within the skill of the art to locate or relocate the counterweight, winch and motor and specific positioning is not critical to the operation of this invention.
In many instances it is desirable to have lower section 12 of the door fold outwardly and upwardly in order to allow maximum storage space within the building housing the bifold closure. An application already mentioned is an airplane hangar wherein the nose of the airplane nearly touches the door. FIGS. 8, 9 and 10 show an embodiment of the invention wherein section 11 pivots inwardly and section 12 folds outwardly and under section 11 and wherein the winch and counterweight are positioned away from the door. In this instance cable 15a would pass over pulleys 16a and 16b and be joined with cable 15b just after cable 15b had passed over pulley 16b. Cable 15b would pass under and around pulley 16c and be joined with cable 15c just after that cable had passed over pulley 16c. The resultant cable designated as cable 15d in FIG. 8 would pass around pulley 16d, through the structure wall as shown in FIG. 9, and then to winch 17 which is remotely located. Cables 15a and 15b cables 15b and 15c are joined by clamps 18 and are separated from each other by cable dividers 19 as previously described. It is noted in this situation that the cables would be mounted on the outside of the door as contrasted to the inside mounting as shown in FIGS. 1-4.
The bifold door 10 may contain a positive locking mechanism as illustrated in FIGS. 1 through 5, 6 and 7 and specifically in FIGS. 6 and 7. As illustrated in FIGS. 1, 3 and 4 the upper section 11 of the bifold door may have permanently attached thereto a restraining bar 41. As illustrated in FIG. 6 which is a section taken along lines 6--6 of FIG. 2 the lower end of restraining bar 41, shown in dotted form, extends down and over the larger section 12 of the bifold door. Restraining bar 41 contains a flat metal extension 47 at the end thereof which is at right angles to bar 47 and which will extend inwardly through section 12 when the door is closed through hole 48. Extension 47 contains a slot 47a near the end designed to engage latch bolt 45 as will be discussed. Section 12 contains a latch 42 on the inside thereof designed to fixedly engage the restraining bar 41 in a vertical position by means of extension 47 thereby preventing the door from folding open.
Latch 42 consists of a latch framework 43 fastened against door section 12 immediately below hole 48. The framework 43 has outward extensions at either end and a spring 44 and latch bolt 45 is connected thereto. Spring 44 rests at the bottom of the lower extension of framework 43. Latch 45 as illustrated is cylindrical in shape at the lower portion but flares outwardly at a 90° angle and becomes a rectangular bar having an angled upper surface. The upper portion of spring 44 rests against the outwardly flared shoulders of the latch bolt 45 so that when the bolt is pushed downwardly the spring is compressed, and when no pressure is placed upon bolt 45 the spring will resume its extended position. There is an aperture in the lower portion of framework 43 to allow the cylindrical end of the latch bolt to pass therethrough. Likewise the top extension of framework 43 contains a rectangular aperture through which the upper end of latch bolt 45 will pass. The upper end of latch 45 is angular in shape so that when the extension 47 comes into contact with latch bolt 45, the latch bolt will move downwardly compressing spring 44 until the extension has passed into a horizontal position, at which time the spring will push the latch bolt upwardly through slot 47a thereby holding restraining bar 41 firmly in place. Attached to the lower portion of latch bolt 45 is a cable 46 or other appropriate means, which is shown in FIG. 6. If this is the only locking mechanism used the door may be opened readily by pulling downward on the cable 46 thereby pulling latch bolt 45 downward below extension slot 47a and pushing inward and upward on the lower section 12 in order to open the door. However, FIGS. 2, 7 and 8 illustrate further locking mechanisms which are preferably used. These locking mechanisms may consist of one or more interconnected triangular shaped latch releases 49, as illustrated in FIG. 2 and more specifically illustrated in FIG. 7 which shows a section taken along lines 7--7 of FIG. 2. The latch releases 49 are connected to the lower section of door section 12 by means of a pivot bolt 51, and are interconnected with each other by means of latch release connectors 50. A foot pedal 52 is connected to one end of latch release 49. The remaining latch releases 49 contain holes in the upper triangular corners thereof, which when foot pedal 52 is depressed downwardly as illustrated in FIG. 8, the hole 49a opposite the foot pedal will move upwardly and since latch release connector 50 will be connected to holes in similar positions in each of the other latch releases, each subsequent latch release 49 will also be caused to rotate in the same direction. However, as illustrated in FIG. 2, cable 46 which is connected into hole 49b will be caused to rotate downwardly when pedal 52 is depressed thereby causing latch bolt 45 to be depressed releasing the restraining bar as already described.
With the depression of foot pedal 52 as shown in the drawings, the latch releases 49 will rotate in a direction to release floor latch 53. Floor latch 53 is similar in construction to latch 52 and consists of a latch framework 54 having upward extensions at the top and bottom thereof. A latch spring 55 and a latch bolt 56 are provided which are similarly shaped to latch spring 44 and latch bolt 45. The latch bolt is connected to the latch release mechanism by means of a connecting rod 57 and the latch bolt when the bifold door is in a completely closed position locks into floor notch or indentation 58. The floor latches are released by depressing pedal 52 which causes latch release mechanism to rotate in a direction which causes the portion of the release containing hold 49a to rotate upwardly, thereby exerting enough pressure on connecting rod 49 which pulls latch bolt 56 free from locking mechanism or floor notch 58 and the door thus can be opened either manually or electrically as described. Obviously, other locking mechanisms may also be utilized without departing from the scope of the present invention. It is also obvious that the locking mechanism may be adapted to a door opening outwardly as well as inwardly.
An advantageous feature of door 10 as also illustrated in FIGS. 1, 3 and 4 is that it is self-sealing against the intrusion of outside elements, such as wind, rain, heat, cold and the like. As illustrated in FIG. 3 and 4, when the bifold door is opened vertically the upper bifold section 11 swings upwardly and outwardly whereas the lower section 12 swings upwardly and inwardly. Attached to upper section 11 is a strip of sealing material or weather stripping 11a, which rises with the door. Likewise, attached to the upper portion of lower section 12 is a weather strip 12a, which is of sufficient length that it rises upwardly with the bifold door but does not extend into the closure opening; in other words, it is approximately the same length as strip 11a. The remaining section of the weather stripping device section 12b is attached to the framework surrounding the opening to be closed so that when the door is in a closed position the top portion of strip 12b just meets strip 12a thereby providing for a complete seal of the sides of the doors 10 against intrusion of outside elements. On an outwardly opening door the positioning of the weather strip would be on the inside of the door and framework.
Although the invention as has been described is deemed to be that which would form the preferred embodiment of the invention, it is recognized that departures may be made therefrom without departing from the scope of the invention which is not to be limited to the details disclosed, but to be accorded the full scope of the claims so as to include any and all equivalent closures. | A closure consisting of a bifold door which is weight balanced in any given position and which, when fully opened, occupies the minimum of space. The door consists of two unequal rectangular bifold sections, the smaller of said sections being the upper section and is pivotally attached along one longitudinal side to the frame or beam at the top of the opening to be closed and the other longitudinal side is pivotally attached in an opposite pivotal direction to the lower, larger rectangular section. The lower section is connected by a system of cables and pulleys to a counterweight which applies an upward force to the bifold door which is equal to the weight or downward force of the bifold door when in a closed, or a partial or fully opened position. When fully opened, the upper rectangular section has pivoted to a position at right angles from its closed position and the lower rectangular section has pivoted 180° in relation to the upper section so as to be folded directly under said upper section. The door may be opened or closed electrically or manually, and when closed, locked in a stationary position. | 4 |
CROSS REFERENCE
[0001] This application claim priority to Provisional Patent Application No. 60/356,595 filed on Feb. 14, 2002, and entitled Medicine Opener, and Provisional Patent Application No. 60/412,645 filed on Sep. 23, 2002, and entitled Container Opener.
FIELD OF THE INVENTION
[0002] The present invention relates to a multifunctional device including various tools for performing many functions required for opening a variety of containers. More particularly, the present invention relates to a multifunctional hand-held device having tools for performing the functions required for opening containers that hold consumer directed products such as, but not limited to, over-the-counter medications, pharmaceuticals or medicants, food and potable beverages.
BACKGROUND OF THE INVENTION
[0003] Often containers used to retain consumer directed products are purposefully designed to be difficult to open in order to prevent or deter tampering with the container's content. For example, cartons, such as, but not limited to, cardboard or corrugated paper food containers may be sealed using an FDA approved adhesive. Food containers may also include an inner foil pack that must be opened by breaking an adhesive or heat-sealed bond. Bottles containing beverages may include twist-off caps that require breaking a safety seal before the cap can be removed, and metal beverage containers may include a push or pull-tab of the type typically contained on soft drink cans. Medicant or pharmaceutical containers may include a safety cap that requires prying the cap off the container or the performance of several motions simultaneously, e.g., pushing down and twisting, in order to remove the cap. These containers may also include a safety seal that must be removed before the container's contents may be accessed. Further still, other forms of medicant or pharmaceutical containers may include adhesively bonded or heat-sealed foil backings bonded to a flexible plastic container. These types of containers include, but are not limited to, blister packs. While the described features, as well as and other similar features not mentioned, serve useful purposes, their presence may severely inhibit access to a container's contents.
[0004] Therefore, there is needed a device that includes tools for assisting with the performance of the functions required for manually opening containers containing consumer directed products. More specifically, there is needed a device for assisting with the performance of the functions required for opening medicine or pharmaceutical containers.
SUMMARY OF THE INVENTION
[0005] This invention relates to a multifunctional container opener for opening a plurality of different containers. The container opener may also be a hand-held device that includes a body that supports a template defining one or more pockets. The template may include a pill splitting tool and compartments or pockets for retaining pieces of the split pill or tablet.
[0006] The body may also support a variety of tools adapted for opening a container or accessing a container's contents. Such tools may include tools for piercing, scoring, or cutting portions of the actual container or safety seals associated with the container. The body may also support a gripping device that facilitates opening various types and sizes of containers that are closed by a top or cap.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] The features and inventive aspects of the present invention will become more apparent upon reading the following detailed description, claims, and drawings, of which the following is a brief description:
[0008] [0008]FIG. 1 is a perspective view of a container opener formed in accordance with the teachings of the present invention.
[0009] [0009]FIG. 2 is a section view showing the pockets of a template defined by the container opener shown in FIG. 1.
[0010] [0010]FIG. 3 is a section showing view of a pill splitter supported by the container opener shown in FIG. 1.
[0011] [0011]FIG. 4 is a top view showing the container opener of shown in FIG. 1 being used to remove a filler material from a container.
[0012] [0012]FIG. 5 is a section view illustrating one use of the container opener shown in FIG. 1.
[0013] [0013]FIG. 6 is a bottom view of the container opener shown in FIG. 1.
[0014] [0014]FIG. 7 is a detail view demonstrating one use of a piercing tool supported by the container opener shown in FIG. 1.
[0015] [0015]FIG. 8 is an elevation view demonstrating one use of the container opener shown in FIG. 1.
[0016] [0016]FIG. 9 is top view of illustrating additional features that may be supported by the container opener shown in FIG. 1.
[0017] [0017]FIG. 10 is a section view showing a pill carrier that may be supported by the container opener shown in FIG. 9.
[0018] [0018]FIG. 11 is an exploded view illustrating one method for securing the pill carrier shown in FIG. 10 to the container opener shown in FIG. 9.
[0019] [0019]FIG. 12 is a section view illustrating a pill-crushing feature that may be included in the pill carrier shown in FIG. 10.
[0020] [0020]FIG. 13 is a bottom view of the container opener shown in FIG. 9.
DETAILED DESCRIPTION
[0021] A detailed description of the present invention is described herein with reference to the accompanying drawing figures. Terms of reference such as “top,” “bottom,” “front,” “back,” or “side” are used to facilitate an understanding of the present invention in view of the accompanying figures. The identified reference terms or other similar terms are not intended to be limiting, and one of ordinary skill in the art will recognize that the present invention may be practiced in a variety of spatial orientations without departing from the spirit and scope of the invention.
[0022] [0022]FIG. 1 shows a container opener 10 formed in accordance with the teachings of this invention. The configuration shown in FIG. 1 may be used to open or facilitate access to the contents of a variety of containers. The container opener 10 shown in FIG. 1 includes a body 12 molded as a one-piece structure. Plastic materials such as ABS, polyethylene, polypropylene, vinyl, nylon, or other materials having similar strength and durability may be used to form the body 12 . It will also be appreciated by those of ordinary skill in the art that the body 12 could be molded as one or more separate elements that may be secured to or supported by the body using techniques known and used by those of ordinary skill in the art.
[0023] The container opener 10 as shown in FIG. 1 shows the body 12 molded into the form of a cat. It will be appreciated, however, by those of ordinary skill in the art that the body 12 could be formed using any variety of shapes, including but not limited to common geometric shapes, various animal shapes, numerals, letters, etc.
[0024] As best seen in FIGS. 1, 2 and 3 , the body 12 includes a cup-shaped center portion 14 surrounding a hollow center 13 . As best seen in FIGS. 3 and 6, the cup-shaped center portion 14 also includes a flat bottom edge portion 16 . The cup-shaped portion 14 may be molded to include a template 18 that defines one or more variously sized pockets 20 . As best seen in FIG. 3, the pockets 20 may extend downwardly from the cup-shaped portion 14 , each terminating in a closed bottom surface 17 positioned just above the bottom edge surface 16 .
[0025] As shown in FIG. 2, the pockets 20 may be configured in a variety of shapes. As shown in FIG. 2, a pocket 20 may be used by placing the back portion 3 of a pill container 4 such as a blister pack over the opening of the pocket 20 , ideally the foil backing of the container 4 will have been scored or pierced prior to placing the foil backing over the pocket 20 . As best illustrated in FIG. 2, the application of an appropriate pressure to the front surface of the pill container 4 causes a pill 5 to fall from the pill container 4 and into the pocket 20 .
[0026] The template 18 may also include a pill splitter 22 , as best seen in FIGS. 3 and 4. The pill splitter 22 may be integrally formed with the body 12 and may include a pocket 24 that is divided into two compartments by an upwardly extending wall 26 . The wall 26 defines a pointed upper edge portion 28 . As best seen in FIG. 3, when a pill 5 is pressed against the upper edge portion 28 and a downward force applied to the pill 5 , the pill 5 may break into two or more pieces. Ideally, the pill 5 breaks as shown in FIG. 3 and falls into the compartments of pocket 24 .
[0027] Referring now to FIG. 8, the body 12 may be molded to include a flat surface 29 , which may be used as a finger rest or guide. Adjacent the flat surface 29 , the body 12 may support an integrally formed outwardly extending member 30 . Outwardly extending member 30 defines a prying tool 32 that may include a flat downwardly sloping surface 31 that terminates at a pointed edge 33 . The pointed edge 33 is contiguous with a flat bottom surface 35 , as best seen in FIG. 6.
[0028] [0028]FIG. 5 shows the prying tool 32 used to remove a cap 2 from a pill container 1 . Typically, containers of the type shown in FIG. 5 are configured to permit the cap 2 to be pried off the container 1 once mating arrows (not shown) on the cap 2 and container body have been aligned. For example, once the mating arrows (not shown) have been aligned, the pointed edge 33 may be inserted between the container 1 and cap 2 as shown in FIG. 5. The downwardly sloping surface 31 may then be used to apply an upward force against the cap 2 , thereby causing the cap 2 to pull away from the container body, as shown in FIG. 5.
[0029] Referring now to FIGS. 1, 6 and 7 , the outwardly extending member 30 may also support a piercing tool 36 . The piercing tool 36 may include a flat body portion 37 that culminates in a pointed edge 39 . As illustrated in FIG. 7, the pointed edge 39 may be used to score or create an opening in the backing of containers such as but not limited to blister packs, foil packs, corrugated boxes or containers or to pierce materials such as packing tape or other similar materials.
[0030] Turning again to FIG. 1, the body 12 may also support an integrally formed outwardly extending, elongated member 38 . As best seen in FIGS. 1 and 6, the elongated member 38 may include top and bottom surfaces 40 , 42 . The elongated member 38 may also define a notch 44 a sidewall surface 43 positioned between the top and bottom surfaces 40 , 42 . The elongated member may also include a distal end that forms a rounded pointed edge 46 .
[0031] As best seen in FIG. 4, the elongated member 38 may be used to remove a filler material such as cotton from a medicine container 1 . For example, the elongated member 38 is inserted into the container and the pointed edge 46 or the notch 44 may be used to grab the filler material. FIG. 4 illustrates using the notch 44 to grab a portion of the filler material.
[0032] Referring now to FIGS. 2, 3 and 6 , an elastomeric pad 48 may be supported within the hollow center 13 defined by body 12 . In one embodiment, the elastomeric pad 48 may be rubber or another material having similar properties. As shown in FIG. 3, the elastomeric pad 48 is positioned in the hollow center 13 so as to fit flush against the bottom surface of the pockets 20 . The elastomeric pad 48 may be secured in position by an adhesive applied to either the elastomeric pad 48 , the bottom portion of the mating pocket 20 surfaces or both. It will be appreciated that other techniques known and used in the industry may be used to secure the elastomeric pad 48 to the body 12 . For example, the elastomeric pad could be integrally molded with the body 12 .
[0033] Referring now to FIGS. 1 and 2, the elastomeric pad 48 may be used to facilitate removal of a cap 2 from a container 1 . As shown in FIGS. 1 - 2 , the opener 10 is brought into contact with a container 1 such that the top of the container cap 2 rests against the elastomeric pad 48 . When pressed against the cap 2 , as shown in FIG. 2, the elastomeric pad 48 remains wholly or substantially flat. As the opener 10 is twisted, as shown in FIG. 1, the cap 2 begins to turn. In some instances, both a downward and twisting motion must be applied to the cap 2 in order to remove the cap 2 from the container 1 .
[0034] Referring now to FIGS. 6 and 8, a second prying tool 50 may be supported within the hollow center 13 . The second prying tool 50 may be molded as part of the template 18 . For example, as best seen in FIGS. 4, 6 and 8 , a pocket 20 a defined by the template 18 may be molded so as to extend though the hollow center 13 , forming a rectangularly shaped body portion 52 . The rectangularly shaped body portion 52 includes a partially open top surface 54 . The rectangularly shaped body portion 52 may also include an endwall portion 56 that includes a tab 57 that extends outwardly from the endwall portion 56 so as to partially cover the open top surface 54 .
[0035] As best seen in FIG. 8, the second prying tool 50 may be used, for example, to remove a safety seal from the opening of a container 1 . For example, the tab 57 may be used, for example, to lift one edge of the safety seal 8 from the container 1 or to lift the pull-tab of the type used on metal beverage containers.
[0036] Referring back to FIGS. 6 and 8, the container opener 10 may also support an integrally formed raised pocket 58 . A magnet 59 may be received within and retained by the raised pocket 58 . The magnet 59 may be secured within the raised pocket 58 using an adhesive. For example, one method of securing the magnet 59 in place includes applying a double-sided adhesive backing a (not shown). One surface of the magnet may be secured to metal flanges (not shown) that are molded into the interior of the raised pocket 58 , and the other side of the magnet may be exposed as best seen in FIG. 8.
[0037] The magnet 59 may be used, for example, to secure the container opener 10 to metallic surfaces or to assist with the opening of metal containers or for lifting metal objects. For instance, the magnet may be used to lift the lid portion of a metal container out of the container's central cavity once the lid has been cut away from the container using a conventional can opener.
[0038] Another configuration of a container opener 100 formed in accordance with the teachings of this invention is shown in FIGS. 9 - 13 . It will be appreciated by one of ordinary skill in the art that one or more of the features shown in FIGS. 9 - 13 could also be incorporated into container opener 10 . However, for purposes of clarity and to keep the drawings simple and easy to read, the features of container opener 100 are illustrated by reference to FIGS. 9 - 13 .
[0039] Referring now to FIGS. 9 and 13, container opener 100 is virtually identical to container opener 10 with regard to construction and use. The container opener 100 is molded as a one-piece structure. As best seen in FIG. 9, the body 101 supports an outwardly projecting member 93 that includes an arcuate shaped surface 95 . At one end, the arcuate shaped 95 surface terminates in a blunt end 97 . At the opposite end, the arcuate shaped surface 95 supports a two-pronged member 99 . The combination of elements 95 , 97 and 99 defines a tool that may be used, for example, to remove metal bottle tops from glass. For example, a bottle cap may be removed by placing the arcuate surface 95 against the top surface of the bottle cap such that the top prong of the 2-prong member 99 is positioned along the bottom edge of the bottle cap. By rotating the container opener 100 in an upward manner, the top prong of the 2-prong member 99 forces the bottle cap out of position.
[0040] Referring back to FIGS. 9 and 13, the body 101 is shown as including a top surface 103 and a bottom surface 102 . The top surface 103 of the container opener 100 may support a magnifying glass 104 . As best seen in FIG. 9, the magnifying glass 104 may be coupled to the body 101 by placing an opening 106 defined by the housing supporting the magnifying glass over an outwardly extending post 107 integrally formed with the body 101 .
[0041] The body 101 also supports an elongated member 108 . The elongated member 108 is virtually similar to the elongated member 38 previously described. However, elongated member 108 may include an elongated flat end 110 that intersects an arcuate notch 112 . This construction may permit the elongated member to be used to open containers or to pierce packages.
[0042] The elongated member 108 may also support a cutting tool 114 . As shown in FIG. 8, the cutting tool may be positioned in a U-shaped area 117 formed by the elongated member 108 . The cutting tool 114 may be formed of metal, and may include an appropriately sharpened upper edge 116 . The cutting tool may be a device such as a razor blade that has been molded into the elongated member 108 . One use of the blade may be to open packages such as envelopes.
[0043] Referring now to FIG. 10, the top surface 103 of the body 101 may support a removable pill carrier 118 . The removable pill carrier 118 includes a top surface 120 coupled to a bottom surface 122 by a hinge connection 124 . The top and bottom surfaces 120 , 122 are coupled so that the top surface 120 pivots upward when a downward pressure is applied to the hinge 124 . As best seen in FIG. 10, when closed, the pill carrier 118 defines a pocket 126 between the top and bottom surfaces 120 , 122 .
[0044] The pill carrier 118 may be selectively removably coupled to the top surface 103 of the body 101 by a snap-fit. As best seen in FIG. 10, the pill carrier 118 may include a rear surface 128 that supports a raised arcuate member 130 . The arcuate member 130 may include a small indentation 132 . The small indentation 132 is designed to received a rounded pointed end of an elongated finger 134 supported by an elongated support 136 molded as part of the top surface 103 of the body 101 . Alternatively, as shown in FIG. 13, the pill carrier 118 may be secured to the body 101 by snap fitting the pill carrier into opening (not shown) defined by each of the L-shaped rectangular support members 113 .
[0045] Alternatively, as shown in FIG. 11, the pill carrier 118 may also be used as a paper clip or similar device for supporting lightweight objects such as paper or cloth.
[0046] As best seen in FIG. 12, the pill carrier 118 may be configured to include pill-crushing surfaces 138 , 140 . As best seen in FIGS. 11 and 12, the pill-crushing surface 138 may include a concave shape, whereas the opposing crushing surface 140 may include a convex configuration.
[0047] [0047]FIG. 12 illustrates one method of using the pill crusher. For example, FIG. 12 illustrates placing a pill between the pill crushing surfaces 138 , 140 and applying a downward force to the top surface 120 , causing the pill to be crushed between surfaces 138 , 140 .
[0048] Referring again to FIG. 13, the bottom surface 103 of the container opener 100 may include a closed-bottom opening 144 surrounded by a serrated sidewall surface 146 . One use of this particular tool may be to open containers such as, for example, jars or containers such as, for example, plastic soda bottles. FIG. 13 also shows a pill splitter 148 that is identical to the spill splitter 22 previously described.
[0049] The bottom surface 102 of container opener 100 may support an elastomeric pad (not shown) within the opening 144 . The elastomeric pad may be identical to elastomeric pad 48 , and may be secured to the body 101 in the manner previously described for elastomeric pad 48 . Additionally, the elastomeric pad may include the template 18 and pockets 20 molded into at least a part of the elastomeric pad.
[0050] Referring now to FIGS. 10 and 13, there is shown a tool 150 that includes an arcuate body portion 152 , a right side portion 154 and a left side portion 156 that defines a flat edge (not shown). The tool 150 may be used, for example, to break the vacuum seal on a vacuum-sealed jar, such as for example, a jar of jam. For instance, the tool 150 may be placed on the top of a vacuum-sealed cap such that flat edge portion of the edge 156 rests on the bottom of the cap and the top of the cap makes contact with the bottom surface 102 of the container opener 100 . The vacuum seal may be broken, for example, by rocking the tool 150 such that the flat edge portion of edge 156 lifts the cap away from the sides of the sides of the jar, wherein the lifting away is just enough to release the vacuum seal.
[0051] Illustrative embodiments of the present invention have been disclosed. A person of ordinary skill in the art would realize, however, that certain modifications would come within the teachings of this invention. Therefore, the following claims should be studied to determine the true scope and content of the invention. | A multifunctional container opener for opening a plurality of different containers, including a body that supports a template defining one or more pockets and a pill splitting tool and one or more compartments or pockets for capturing pieces of the split pill or tablet. The body may also support a variety of tools adapted for opening a container or accessing a container's contents. Such tools include tools for piercing, scoring, cutting or prying portions of the actual container or safety seals associated with the container. The body also supports a gripping device for frictionally engaging the cap or top of a container. | 1 |
BACKGROUND OF THE INVENTION
A thermal cycle of a heat engine that employs a quantity of gas as an operating medium can be described by reference to a pressure-volume (P-V) diagram. FIGS. 1 and 2 show P-V diagrams for two well-known thermal cycles, the Carnot cycle ( FIG. 1 ), and the ideal Sterling cycle ( FIG. 2 ).
The net energy delivered from one thermal cycle is the area of the loop swept out by the operating path in the P-V plane. In the course of each cycle, energy is delivered by the engine for part of the cycle, and is absorbed by the engine for the remainder of the cycle. For some parts of some cycles, energy is neither stored nor delivered. For instance, in the ideal Sterling cycle, mechanical energy is neither absorbed nor delivered during those parts of the cycle where the trajectory is parallel to the P-axis.
By necessity, part of the system used for extracting a net positive average power output must include a device for storing and returning energy out of and into the heat engine, on a cyclic basis. In conventional heat engines, this cyclic energy storage is accomplished by mechanical means, for example via the rotational inertia of a crankshaft with flywheel attached.
SUMMARY OF THE INVENTION
It is desirable to be able to convert heat into electricity by means of a method in which the equipment is reliable, efficient, quiet, free of vibration, and capable of operating from a variety of fuels.
It is also desirable to be able to use electricity to effect heat transfer by means of equipment with such attributes.
To achieve these and other objectives, an embodiment of the invention provides a method for generating electrical energy using a thermal cycle of a working gas. The method comprises using the motion of a piston in a cylinder, containing the working gas performing the thermal cycle, to electromagnetically induce current in an electrical circuit coupled to the cylinder. The electrical circuit is used to store the electrical energy, produced by the current induced in the electrical circuit, in an electrical storage device; and the electrical energy stored in the electrical storage device is used to electromagnetically provide a motive force to the piston. Cyclically using the electrical circuit to store the electrical energy and using the stored energy to provide a motive force to the piston effect a net positive average power transfer into the electrical storage device over the course of the thermal cycle.
The electrical circuit may comprise an electronic power converter, and the method may further comprise using the electronic power converter to perform closed-loop electronic control of the motion of the piston. The electronic power converter may perform the closed-loop control based on electrical signals related to the state of the working gas. At least one of a temperature sensor, a pressure sensor, and a position sensor may be used to deliver the electrical signals related to the state of the working gas to the electronic power converter.
The thermal cycle may approximate a Sterling cycle, a Carnot cycle, an Otto cycle, or another thermal cycle. The thermal cycle may receive heat from external combustion, or the working gas may be cycled through an internal combustion cycle.
Compression and expansion of the working gas between a first piston and a second piston may be used to perform the thermal cycle. The electrical circuit may comprise a set of windings coupled to the cylinder, and the method may comprise using the motions of a first permanent magnet attached to the first piston and a second permanent magnet attached to the second piston to electromagnetically induce current in the set of windings. Further, the motions of the first piston and the second piston may be used to move the working gas along the cylinder to effect successive heat transfer with a heating zone and a cooling zone of the cylinder.
At least part of the shaft of the first piston may move concentrically within a shaft of the second piston. The electronic power converter may be used to control timing of the thermal cycle by controlling the motions of the first piston and the second piston; including by controlling the motions of the first piston and the second piston such that the working gas moves between a heating zone, a cooling zone, and a neutral zone of the cylinder. A thermal shade may be attached to the first piston or the second piston to insulate non-working gas within the cylinder; and a paddle may be attached to the first piston or the second piston to create turbulence in the working gas. An external flow return may be used to flow non-working gas between a first end zone and a second end zone of the cylinder. The first piston and the second piston may be mounted around a common centering shaft.
Two cylinders operating according to the invention may be operated in axial opposition to each other. Similarly, four cylinders may be operated in a bundle with parallel axes of the cylinders, two of the cylinders being operated antiparallel to the other two cylinders of the bundle.
In another embodiment according to the invention, there is provided a method for powering a heat pump using electrical energy, the heat pump performing a thermal cycle. The method comprises using electrical energy stored in an electrical storage device to electromagnetically provide a motive force to a piston in a cylinder containing the working gas performing the thermal cycle. The motion of the piston is used to electromagnetically induce current in an electrical circuit coupled to the cylinder; and the electrical circuit is used to store the electrical energy, produced by the current induced in the electrical circuit, in the electrical storage device. Cyclically using the stored energy to provide the motive force to the piston and using the electrical circuit to store the electrical energy effect a net positive average power transfer out of the electrical storage device over the course of the thermal cycle. Similar methods as those used with the method for generating electrical energy, above, may be used with the method for powering a heat pump.
BRIEF DESCRIPTION OF THE DRAWINGS
The foregoing and other objects, features and advantages of the invention will be apparent from the following more particular description of preferred embodiments of the invention, as illustrated in the accompanying drawings in which like reference characters refer to the same parts throughout the different views. The drawings are not necessarily to scale, emphasis instead being placed upon illustrating the principles of the invention.
FIG. 1 shows a pressure-volume diagram for a Carnot cycle, known in the art;
FIG. 2 shows a pressure-volume diagram for an ideal Sterling cycle, known in the art;
FIG. 3A shows an arrangement of coils, magnets, and pistons for an external combustion cylinder according to an embodiment of the invention;
FIG. 3B shows a separate view of a piston for the embodiment of FIG. 3A ;
FIG. 4 is a schematic diagram of electrical components that are coupled to the external combustion cylinder arrangement of FIGS. 3A-3B ;
FIG. 5A illustrates an alternative embodiment that may be used in place of the mechanical arrangement of FIG. 3A , in accordance with an embodiment of the invention;
FIGS. 5B and 5C show separate views of pistons for the embodiment of FIG. 5A ;
FIG. 6 is a timing diagram for the heat engines of FIGS. 3A and 5A when operated as electricity generators per the Sterling cycle depicted in FIG. 2 , in accordance with an embodiment of the invention;
FIG. 7 is a P-V diagram for a Sterling cycle heat pump operated in accordance with an embodiment of the invention;
FIG. 8 is a timing diagram for the Sterling cycle heat pump of FIG. 7 ;
FIG. 9 illustrates an alternative embodiment that may be used in place of the mechanical arrangements of FIGS. 3A-3B and 5 A- 5 C, in accordance with an embodiment of the invention;
FIG. 10 shows an axially opposed heat engine according to an embodiment of the invention;
FIGS. 11A and 11B illustrate an arrangement of four of the cylinder assemblies of the type shown in FIG. 5A placed side-by-side with parallel central axes, according to an embodiment of the invention;
FIG. 12 is a timing diagram for the heat engines of FIGS. 3A and 5A when operated as electricity generators per the Carnot cycle depicted in FIG. 1 , in accordance with an embodiment of the invention;
FIG. 13 is a cross-sectional view of a piston arrangement for an internal combustion generator, in accordance with an embodiment of the invention;
FIG. 14 is a timing diagram for an internal combustion generator, in accordance with an embodiment of the invention; and
FIG. 15 is a P-V diagram of an Otto cycle by which an internal combustion generator may be operated, in accordance with an embodiment of the invention.
DETAILED DESCRIPTION OF THE INVENTION
Rotational inertia has been the method of choice for cyclic energy storage in heat engines since their development in the eighteenth century. Thus, the devices used for cyclically storing and returning energy out of and into the heat engine are typically mechanical. For example, an engine may use the rotational inertia of a crankshaft with flywheel attached for cyclical energy storage. In this way, conventional heat engines can be said to use mechanically-coupled thermal cycles.
However, in such a mechanically-coupled thermal cycle the motion of the pistons is constrained by the motion of the crankshaft. The pistons therefore cannot move in a manner that allows the state of the working gas to closely follow the desired P-V cycle. The relative amounts of time devoted to each segment of the cycle are fixed by the mechanical constraints on the motion of the flywheel. Moreover, mechanically-coupled heat engines are constrained in their reliability and efficiency, the amount of noise and vibration they generate, and their ability to operate from a variety of fuels.
In order to improve on these characteristics, an embodiment according to the invention uses an electricity storage device to accommodate the cyclic flow of energy from a thermal cycle. The thermal cycle can therefore be described as electrically-coupled.
An embodiment uses direct electric drive of pistons by means of electromagnetic shear.
Electricity storage devices suitable for this application include, for example, capacitors, batteries, and (if available) superconducting coils. Direct electric drive using electromagnetic shear may be accomplished with the use of permanent magnets attached to each piston assembly, and with the use of controlled electric currents in coils or windings to provide force to, or electromagnetic induction from, the permanent magnets.
Embodiments of an electrically-coupled thermal cycle may be used for the generation of electricity from a thermal cycle, such as to charge a battery using the external or internal combustion of a gas; or for electrical powering of a thermal cycle, such as using a battery or other source of direct current to power a heat pump.
In accordance with the invention, power electronic circuits can be built which permit the motion of the pistons to be controlled so as to follow as closely as possible any desired path in the P-V plane. The necessary energy cycling required to extract average power from a heat engine can be effected via electrical energy storage. The use of electric coupling in this manner allows for variation of the amounts of time spent in each segment of a P-V cycle, thereby allowing for high thermal cycle efficiencies.
Therefore, by comparison with prior systems in which energy was cyclically stored mechanically, an embodiment according to the invention uses electrical storage of cyclical energy flow. In addition, use of electrical circuitry allows closed-loop electrical control of piston motion.
In the prior art, refrigeration devices are known that are driven by electronic linear drive motors, such as in U.S. Pat. No. 4,761,960 of Higham et al.; U.S. Pat. No. 4,697,113 of Young; and U.S. Pat. No. 5,040,372 of Higham. Further, such linear drive motors may be battery-powered, with the delivery of current from the battery being electrically controlled, as in U.S. Pat. No. 5,752,385 of Nelson and U.S. Pat. No. 4,434,617 of Walsh. Also, free-piston hydraulic engines are known, such as in U.S. Pat. No. 4,215,548 of Beremand.
However, an embodiment according to the present invention is fundamentally different from such previously known systems because it employs electrical storage of cyclical energy flows to and from the thermal cycle. Thus, within a thermal cycle, an embodiment according to the invention cycles energy into and out of an electrical storage device that is electrically coupled to a cylinder containing the piston. By contrast, such previously known systems did not use electrical storage of cyclical energy flow. Some such prior systems may instead use a form of mechanical resonance for cyclical energy flow. For example, in U.S. Pat. No. 4,434,617, a mechanical resonance is used between the mass of the piston and the compressed end-zone gas, which acts as a spring, for cyclical energy flow. Although a synchronized electrical drive is used to assist and maintain the mechanical resonance, the system does not use an electrical storage device to absorb the cyclical energy flow from the thermal cycle. Such systems therefore do not allow the potential improvements in thermal efficiency provided by using electrical storage of cyclical energy flows from a thermal cycle, and electronic control of the cyclical energy flows, according to an embodiment of the invention.
A description of preferred embodiments of the invention follows.
FIGS. 3A and 3B show an arrangement of coils, magnets, and pistons for an external combustion generator according to an embodiment of the invention. In the cross-sectional view of FIG. 3A , a closed gas containment cylinder 301 contains a body of gas, a portion of which becomes the working gas 302 . The working gas 302 is the subset of the total gas within the cylinder 301 that lies between two pistons 303 and 304 , which slide within the cylinder 301 . The pistons 303 and 304 maintain a tolerably good gas seal with the inner wall of the cylinder 301 without creating undue friction. Conventional piston rings, for example, may be employed for this purpose. The cylinder 301 will typically be of circular cross section, but may have other cross sectional shapes. The working gas 302 may be any gas suitable for the purpose, such as air, nitrogen, helium, or hydrogen.
As shown in FIG. 3B , each of the two pistons 303 and 304 is in the form of a plate. Attached centrally and perpendicular to each plate 303 and 304 is a shaft 307 and 308 attached at its other end to a permanent magnet plate 305 and 306 . The permanent magnet plates 305 and 306 contain permanent magnets within them, suitably arranged, together with magnetic path material such as iron or a suitable grade of steel. The arrangement of the permanent magnets and magnetic path material is such as to produce magnetic flux emanating from the outer edges of the permanent magnet plates 305 and 306 , which cuts through the drive windings 309 and 310 surrounding the cylinder 301 ( FIG. 3A ). The cylinder 301 is made of nonmagnetic materials. A plurality of such materials may be employed to construct cylinder 301 . For example, a material such as aluminum may be used for regions such as 313 and 314 , where heat flow is required; and a material such as ceramic or fiberglass may be used for regions such as 317 , where heat flow is not required. Surrounding the drive windings 309 and 310 are magnetic field return paths 311 and 312 made of magnetic path material.
Also surrounding the cylinder 301 are two heat transfer zones 313 and 314 made of thermally conductive material such as copper or an aluminum alloy. A heating zone 313 accepts heat from an external heat source, for example a flame or solar collector, and transfers that heat into the working gas 302 at an appropriate time, as described below. Likewise, a cooling zone 314 extracts heat from the working gas 302 at an appropriate time, also described below. The heat transfer zones 313 and 314 are separated from each other by a thermally insulated neutral zone 317 . The three zones 313 , 314 , and 317 are shown in the accompanying figures to be of comparable lengths, which is not necessarily required, but may be advantageous with regard to optimization of overall power output.
FIG. 4 is a schematic diagram of electrical components that are coupled to the external combustion cylinder arrangement of FIGS. 3A-3B , in order to accommodate the cyclic flow of energy from the thermal cycle in accordance with an embodiment of the invention. Drive windings 409 , 410 , 443 , which are the drive windings depicted as 309 , 310 of FIG. 3A , connect to an electronic power converter 435 . FIG. 4 shows three isolated windings 409 , 410 , 443 for illustrative convenience, but any number of separate windings may be employed, as necessary. Also connected to the electronic power converter 435 are signals from position sensors 436 , a temperature sensor 440 , and a pressure sensor 441 . It will be appreciated that any appropriate number of such position, temperature, and pressure sensors may be employed. The position sensors 436 give the electronic power converter 435 the information it needs to know the exact location of each piston at any instant in time. The temperature sensor 440 and pressure sensor 441 inform the electronic power converter 435 of the state of the working gas 302 at any instant.
Electronic power converter 435 is connected to a DC Bus 442 , to which is connected a capacitor 437 and/or a battery 438 , and an electric load 439 . The electric load 439 may be disconnected from the DC Bus 442 when not required, while the electronic power converter 435 continues to charge the battery 438 . Suitable batteries for battery 438 include lithium or other modem types of batteries configured for energy cycling applications, with better performance gained by lithium or other types of batteries capable of cycling energy at a rate of a few cycles per second or faster.
During operation of the system, the electronic power converter 435 of FIG. 4 controls the flow of electric current into and out of the windings 309 and 310 of FIG. 3A such that pistons 303 and 304 move up and down within the cylinder 301 to cause the working gas 302 to follow a desired P-V cycle. The capacitor 437 and battery 438 act as the energy reservoir for the system, and absorb the cyclic energy variations which are integral to the cycles of heat engines. The electronic power converter 435 stores little or no energy, and transfers power between the DC Bus 442 and the windings 309 and 310 in a highly efficient manner.
In this way, the embodiment of FIGS. 3A-4 provides an electrically-coupled external combustion generator. Energy released from external combustion is transferred into the cylinder 301 through heating zone 313 , a pressure-volume cycle is produced in working gas 302 , and cyclic energy storage is performed by the electrical circuitry of FIG. 4 . In one application, for example, the external combustion of a gas may therefore be used to store electrical charge in battery 438 without using any moving parts other than the pistons 303 and 304 .
FIGS. 5A-5C illustrate an alternative embodiment that may be used in place of the mechanical arrangement of FIGS. 3A-3B , wherein the drive windings 509 and 510 are placed adjacent to each other and away from the heating zone 513 . By placing the permanent magnet plates 505 and 506 away from the heating zone 513 , this arrangement simplifies the design task of keeping the permanent magnets cool. Neodymium-iron permanent magnet material loses its magnetism when subjected to high temperatures, and is limited to working temperatures typically no higher than 150 to 200 C. As shown in FIG. 5A , the shaft 507 of a longer piston assembly (shown separately in FIG. 5B ) lies concentrically within the shaft 508 of a shorter piston assembly (shown separately in FIG. 5C ). The mechanical fit between these two shafts 507 and 508 is such as to give a tolerably good gas seal between them without creating undue friction. The inner shaft 507 , which connects piston 503 to its permanent magnet plate 505 , is constructed to give minimal heat conduction from the hot upper end 503 to the permanent magnet plate 505 and to the shaft 508 surrounding it. This may be effected by using a thermally insulating material such as ceramic for shaft 507 , possibly with a metallic core for strength. The drive windings 509 for the longer piston assembly 503 are located further away from the cooling zone 514 than the drive windings 510 for the shorter piston assembly 504 . In FIG. 5A (unlike with plates 305 and 306 in FIG. 3A ), permanent magnet plate 506 is located above permanent magnet plate 505 , because piston assembly 503 is longer than piston assembly 504 . The operation of the heat engine depicted in FIG. 5A is just as described above for the heat engine depicted in FIG. 3A , with similar electrical coupling to circuitry such as that of FIG. 4 .
FIG. 6 is a timing diagram for the heat engines of FIGS. 3A and 5A when operated as electricity generators per the Sterling cycle depicted in FIG. 2 , in accordance with an embodiment of the invention. Curve 644 is the piston position profile for piston 303 , 503 , and curve 645 is the piston position profile for piston 304 , 504 , for a repeating cycle A-B-C-D-A. The piston positions are indicated by position levels 0 through 3 on the y-axis of FIG. 6 , which correspond to cylinder positions indicated in FIGS. 3A and 5A . The cooling zone 314 , 514 extends from position level 0 to level 1 ; the neutral zone 317 , 517 extends from position level 1 to level 2 ; and the heating zone 313 , 513 extends from position level 2 to level 3 . Although FIG. 6 shows the amount of time spent in each of the four segments of the thermal cycle as approximately equal, it is to be understood that the duration of each segment can be varied independently of the others, thereby allowing for power output variation and efficiency maximization. In varying the duration of the segments, there is an inherent conflict between the objectives of maximizing power output and maximizing efficiency; either objective can be satisfied, but not both simultaneously.
Between times A and B of FIG. 6 the working gas 302 , 502 is compressed at constant temperature T 1 . In the A-B path, piston 304 , 504 is held at position Level 0 (shown on the y-axis of FIG. 6 , and in FIGS. 3A and 5A ) as shown by curve 645 , while piston 303 , 503 is moved from position Level 2 to Level 1 as shown by curve 644 , thereby compressing the working gas 302 , 502 . The motion 644 of piston 303 , 503 for this segment is depicted as having a straight-line shape in FIG. 6 , although in practice the motion will typically be nonlinear.
Between times B and C of FIG. 6 , the working gas 302 , 502 is held at constant volume and heated to temperature T 2 . In the B-C path, both pistons initially move quickly together such that piston 303 , 503 is moved from position Level 1 to Level 3 , while piston 304 , 504 is moved from position Level 0 to Level 2 , as indicated by curves 644 and 645 . For the duration of the B-C time segment, piston 304 , 504 is held at position Level 2 (curve 645 ), and piston 303 , 503 is held at position Level 3 (curve 644 ).
Between times C and D of FIG. 6 , the working gas 302 , 502 expands at constant temperature T 2 . In the C-D path, piston 303 , 503 is held at position Level 3 (curve 644 ), while piston 304 , 504 is moved from position Level 2 to Level 1 (curve 645 ). The motion of piston 304 , 504 for this segment is depicted as having a straight-line shape in curve 645 of FIG. 6 , although in practice the motion will typically be nonlinear.
Between times D and A of FIG. 6 , the working gas 302 , 502 is again held at constant volume and is cooled to temperature T 1 . In the D-A path, both pistons initially move quickly together such that piston 303 , 503 is moved from position Level 3 to Level 2 (curve 644 ), while piston 304 is moved from position Level 1 to Level 0 (curve 645 ). For the duration of the D-A time segment, piston 304 , 504 is held at position Level 0 (curve 645 ), and piston 303 , 503 is held at position Level 2 (curve 644 ).
Examination of the timing diagram of FIG. 6 shows that there are portions of the cycle wherein the pistons are stationary. These regions may afford an opportunity for efficiency improvement, whereby a mechanical means is used to hold each piston in its appointed place during a stationary portion of the cycle rather than relying on the flow of electric current in the drive windings, with its attendant ohmic losses. For instance, during the compression region A-B in FIG. 6 , piston 304 , 504 could be prevented from moving even lower than position Level 0 by a mechanical impediment. The state of pressure in the end zones 315 / 515 , 316 / 516 will be a factor in the implementation of this technique, and the design of the end zones may need to be modified accordingly.
Such mechanical hard stops could, in principle, take the form of a mechanical barrier, or they may be effected by means of permanent magnets (and/or magnetic poles) attached rigidly either to the cylinder 301 , 501 and/or to the piston assemblies. If a mechanical barrier is used, the power electronics can control the motion of the piston as it approaches the barrier so as to effect a “soft landing”. A soft, springy material attached to the barrier or to the piston may assist with ensuring a soft landing. Permanent magnets would have the advantage of maintaining a physical impediment to further motion, without the practical concerns of physical contact associated with mechanical barriers. The permanent magnets can be used either in the attraction mode or in the repulsion mode. If they are used in the attraction mode, the control electronics will need to provide an excess impulse of current in order to break the piston free from its magnetic confinement at the end of the stationary period.
Although a Sterling cycle has been described above, the general arrangement illustrated by FIGS. 3A-5C can be used for other types of thermal cycle, including one which approximates the Camot cycle of FIG. 1 . Such a Camot Engine may operate, for example, via the timing diagram of FIG. 12 , which applies to a physical arrangement in which the length of the neutral zone 317 , 517 is three times that of the heating 313 , 513 and cooling 314 , 514 zones. In FIG. 12 , curve 1244 is the piston position profile for piston 303 , 503 , and curve 1245 is the piston position profile for piston 304 , 504 , for a repeating cycle A-B-C-D-A. Because of the extended length of the neutral zone 317 , 517 , the position levels are shown ranging from level 0 to level 5 , with the cooling zone 314 , 514 extending from level 0 to level 1 , the neutral zone 317 , 517 extending from level 1 to level 4 , and the heating zone 313 , 513 extending from level 4 to level 5 . Time interval A-B corresponds to isothermal compression, interval B-C corresponds adiabatic compression, interval C-D corresponds to isothermal expansion, and interval D-A corresponds to adiabatic expansion.
While the embodiments of FIGS. 3A-5C have been described as generators, by which heat is converted to electricity, it is also possible to use an electrically-coupled thermal cycle in accordance with an embodiment of the invention to create an electrically-powered heat pump. In this case, the embodiments of FIGS. 3A-5C are essentially operated in reverse: energy stored in electrical circuitry such as that of FIG. 4 is cycled in and out of a cylinder 301 , 501 via windings 309 , 509 and 310 , 510 , so that the pistons 303 - 304 and 503 - 504 perform a heat pump cycle. Such a heat pump may be used to generate heat or to receive heat, which can be transferred to or from an external object through heating and cooling zones 313 - 314 and 513 - 514 .
FIG. 7 shows a P-V diagram for such a Sterling cycle heat pump (i.e., a refrigerator) operated in accordance with an embodiment of the invention. It can be seen that the path followed is that of FIG. 2 , taken in reverse. FIG. 8 gives the corresponding timing diagram, which can be understood by reference to the similar preceding explanation for FIG. 6 . Curve 844 is the piston position profile for piston 303 , 503 , and curve 845 is the piston position profile for piston 304 , 504 , for a repeating cycle A-B-C-D-A. The piston positions are indicated by position levels 0 through 3 on the y-axis of FIG. 8 , which correspond to cylinder positions indicated in FIGS. 3A and 5A . The cooling zone 314 , 514 extends from position level 0 to level 1 ; the neutral zone 317 , 517 extends from position level 1 to level 2 ; and the heating zone 313 , 513 extends from position level 2 to level 3 .
FIG. 9 shows an alternative embodiment that may be used in place of the mechanical arrangements of FIGS. 3A-3B and 5 A- 5 C. A centering shaft 921 is located centrally and within the shaft 907 of piston assembly 903 , which in turn is located within the shaft 908 of piston assembly 904 . Again, the mechanical fit between the shafts 921 , 907 , and 908 is such as to give a tolerably good gas seal between them without creating undue friction. Centering shaft 921 holds both piston assemblies 903 , 904 centered within the cylinder 901 , so that they do not cling to one side of the cylinder via magnetic attraction, thereby causing excess friction and compromised gas sealing. The centering shaft 921 therefore assists to improve system efficiency.
In an alternative embodiment according to the invention, portions of centering shaft 921 may be made of magnetic path material encircled by field coils, to create an electromagnet, thereby providing a means for the elimination of permanent magnets in the plates 305 and 306 of FIG. 3A . For example, using field coils wound around each end of such a magnetic centering shaft 921 , two electromagnets may be created, to replace the functional role of permanent magnets in plates 305 and 306 . Plates 305 and 306 are then made of magnetic path material.
Returning to the embodiment of FIG. 9 , thermal shades 922 can be fitted to, or made part of, the pistons 903 and 904 . The function of these thermal shades 922 is to impede the flow of heat through the heating 913 and cooling 914 zones during appropriate portions of the heat cycle. The thermal shades 922 are made of thermally insulating material, and are located close to, but not in contact with, the inside walls of the cylinder 901 . The thermal shades 922 extend around the entire inner perimeter of the inside walls of the cylinder 901 . They impede the flow of heat via radiation, conduction, and convection into and out of the non-working gas within the cylinder 901 , thereby improving system efficiency.
An external flow return 923 is a tube allowing non-working gas to flow from the upper end zone 915 to the lower end zone 916 to permit pressure equalization, which may be necessary to improve system efficiency. An alternative means for achieving this pressure equalizing gas flow, not shown in FIG. 9 , is to provide an internal flow return in the form of a passageway inside the centering shaft 921 , which then takes the form of a hollow tube. The volume of the upper end zone 915 and lower end zone 916 relative to the size of the working region (that is, the region between piston position levels 0 and 3 ) may need to be adequately large in order to maintain system efficiency, by eliminating the requirement for excessive forces to compress the gas in the end zones 915 and 916 . To this end, the external flow return 923 may include one or more expansion chambers (not shown in FIG. 9 ) along its length.
In order to improve the rate of heat transfer through the walls of the heating zone 913 into the working gas 902 , paddles 924 may be attached to the pistons 903 and 904 . These paddles 924 stir the working gas 902 as the pistons 903 and 904 move relative to each other, thereby causing turbulence and motion of the working gas 902 , and helping improve system efficiency. The paddles 924 also improve the rate of heat transfer from the working gas 902 through the walls of the cooling zone 914 . The paddles 924 may have a variety of shapes, consistent with not making contact with each other or with the other piston.
FIGS. 10-11B illustrate methods for reducing vibrations in a power conversion system according to an embodiment of the invention. In FIG. 10 , two of the cylinder assemblies of the type shown in FIG. 5A (or any other cylinder assemblies according to the invention) are arranged so that their central axes are coincident and opposing. The motion of the pistons for the system of FIG. 10 is controlled by their power conversion electronics such that the corresponding pistons move in synchronism in exactly equal and opposite movements. Thus, the two piston assemblies 1003 / 1005 move toward or away from each other at exactly the same speed, and likewise the two piston assemblies 1004 move toward (or away from) each other in synchronism. The upper end zone 1015 is common to both sides of the engine, while there is a separate lower end zone 1016 at each end. Such an arrangement may be referred as an engine with “horizontally opposed” cylinders; or more generally, “axially opposed” cylinders, since the common axis need not necessarily be horizontal. A horizontal placement may have advantages for arrangement of the flow of combustion gases past the heating zones.
In FIGS. 11A and 11B , four of the cylinder assemblies of the type shown in FIG. 5A (or any other cylinder assemblies according to the invention) are placed side-by-side so that their central axes are parallel and arranged in a diamond pattern as viewed end-on (shown in FIG. 11B ). The controlling power electronics ensures that the pistons in cylinders A and C move together in the same direction and in exact synchronism. The pistons in cylinders B and D also move together in the same direction and in exact synchronism, but in exactly the opposite direction to those in A and C, as indicated by the cross and dot vector notation of FIG. 11B . In order to keep the heating zones in all four cylinders close together, the two pairs of cylinders may need to be displaced axially relative to each other rather than having their ends coplanar.
The methods described above can be extended to the implementation of an internal combustion generator, in accordance with an embodiment of the invention. In a similar fashion to that described for FIGS. 3A-4 , the electrical arrangement of FIG. 4 may be used to perform cyclical energy storage for a mechanical piston arrangement of an internal combustion cycle. FIG. 13 is a cross-sectional view of one possible such mechanical arrangement, which can be seen to incorporate features already explained with reference to FIGS. 3A , 5 A, and 9 . In FIG. 13 , two concentric piston assemblies 1303 and 1304 surround a centering shaft 1321 in a cylinder 1301 , as in FIG. 9 . An arrangement corresponding to FIG. 3A could also be implemented, wherein the piston assemblies are physically separate, with or without a centering shaft. In FIG. 13 , a fuel/air mixture is fed into the working gas region 1302 via an inlet valve and port 1332 , and an outlet valve and port 1333 allows for exhaust gas to be ejected. A spark plug 1331 is located at the upper end of the working gas region 1302 . The walls of the working gas region 1302 are thermally insulated, and are made strong enough to withstand the forces associated with ignition of the fuel/air mixture. Other features may be similar to those described above, including concentric shafts 1307 and 1308 , permanent magnet plates 1305 and 1306 , drive windings 1309 and 1310 , magnetic field return paths 1311 and 1312 , and end zones 1315 and 1316 . Exhaust port 1334 provides a means of escape for gas in region 1316 , so that excessive compression forces are not required to compress the gas in region 1316 .
FIG. 14 shows a timing diagram that the internal combustion generator of FIG. 13 may follow while performing an Otto cycle shown in the P-V diagram of FIG. 15 , in accordance with an embodiment of the invention. Curve 1444 is the piston position profile for piston 1303 , and curve 1445 is the piston position profile for piston 1304 , for a repeating cycle A-B-C-D-A. The piston positions are indicated by position levels 0 and 1 on the y-axis of FIG. 14 , which correspond to cylinder positions indicated in FIG. 13 .
Between times A and B of FIGS. 14 and 15 , the inlet valve 1332 of FIG. 13 is open, allowing a fuel/air mixture to be drawn into the working gas region 1302 as piston 1303 is moved from position Level 0 to Level 1 (curve 1444 ). During this segment, piston 1304 is held at position Level 0 (curve 1445 ). The motion of piston 1303 for this segment is depicted as having a straight-line shape (curve 1444 ), although in practice the motion may be nonlinear.
Between points B and C of FIGS. 14 and 15 , the working gas 1302 is compressed as piston 1304 is moved from position Level 0 to Level 1 (curve 1445 ), while piston 1303 remains at Level 1 (curve 1444 ). At point C, spark plug 1331 initiates combustion of the working gas 1302 , at which time the pressure of the working gas 1302 jumps immediately to the higher level shown at C′ in the P-V diagram of FIG. 15 .
Between points C and D of FIGS. 14 and 15 , the working gas 1302 expands, exerting mechanical force on the pistons, and forcing piston 1304 downward (curve 1445 ) while piston 1303 remains at position Level 1 (curve 1444 ). Again, the motion of piston 1304 for this segment is depicted as having a straight-line shape, although in practice the motion may be nonlinear. At point D, exhaust valve 1333 is opened, at which time the pressure of the working gas 1302 falls immediately to the lower level shown at D′ in the P-V diagram.
Between points D and A of FIGS. 14 and 15 , the exhaust valve 1333 remains open, and the burnt working gas 1302 is ejected as piston 1303 is moved from position Level 1 to Level 0 (curve 1444 ), while piston 1304 remains at Level 0 (curve 1445 ).
It can therefore be seen that embodiments according to the invention provide a variety of different possible ways of using electrical storage of the cyclical energy required by a thermal cycle, including external and internal combustion generators, and electrically-driven heat pumps.
While this invention has been particularly shown and described with references to preferred embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the scope of the invention encompassed by the appended claims. | In one embodiment according to the invention, there is provided a method for generating electrical energy using a thermal cycle of a working gas. The method comprises using the motion of a piston in a cylinder, containing the working gas performing the thermal cycle, to electromagnetically induce current in an electrical circuit coupled to the cylinder; using the electrical circuit to store the electrical energy, produced by the current induced in the electrical circuit, in an electrical storage device; and using the electrical energy stored in the electrical storage device to electromagnetically provide a motive force to the piston. Cyclically using the electrical circuit to store the electrical energy and using the stored energy to provide a motive force to the piston effect a net positive average power transfer into the electrical storage device over the course of the thermal cycle. | 7 |
This is a division of application Ser. No. 054,267, filed May 26, 1987, now U.S. Pat. No. 4,801,417 which is a division of application Ser. No. 716,353, filed Mar. 26, 1985, now U.S. Pat. No. 4,685,650, which is a continuation-in-part of application Ser. No. 513,696, filed July 14, 1983, now abandoned, which is a division of application Ser. No. 234,639, filed Feb. 17, 1981, now U.S. Pat. No. 4,422,994.
FIELD OF THE INVENTION
The present invention relates to manhole assembies and the like and more particularly to novel method and apparatus for forming inverts in manhole assemblies through either a single pour or a two pour technique, wherein the inverts formed thereby are in precise alignment with the sidewall openings of the manhole assembly base member.
BACKGROUND OF THE INVENTION
Manhole assemblies are typically comprised of a manhole base, an intermediate or riser section and a top section normally designed to receive the manhole cover. The base section is comprised of a substantially flat base portion and a cylindrical shaped sidewall extending upwardly therefrom and integral therewith. Openings are arranged in the sidewall, each being adapted to receive the end of a pipe for selectively introducing a liquid flow into the invert or removing a liquid flow therefrom. Manhole assemblies are provided whenever a change in slope or angular orientation is encountered from one pipe run to the next. The openings receiving said pipe are arranged in accordance with the pipe runs connected thereto, the invert extending between the side-wall openings may, for example, define a straight line, right angle configuration, or a Y-configuration (in the case of a base member having three openings designed for merging two incoming pipe runs and feeding the combined flow therefrom to a single outgoing pipe run). It is extremely advantageous to maintain a smooth flow through the invert of the base member, thence turbulence resulting from misalignment of the invert relative to the incoming and outgoing pipes significantly increases the development of odious and toxic gases as a result of such turbulent conditions. In addition, a smooth fluid flow also serves to maximize flow rate through the manhole base.
Heretofore, manhole bases have typically been formed in two stages, the manhole base absent the invert being formed at the factory and the invert being formed at the job site after positioning the manhole base in the ground, usually five (5) to fifteen (15) feet below surface. Usually at least one or more workmen descend into the manhole base and set up the channel forming assemblies. The casting material, typically concrete, is also transported to the job site and dropped into the base member from ground level through the manhole assembly and into the bottom of the manhole base, dropping a distance of the order of 15 feet or more before reaching the floor of the manhole base. The workmen encounter cramped working conditions within the manhole assembly and are constrained to stand upon the channel forming apparatus during the time that the casting material is being poured, and while the casting material is setting. The workmen must also support themselves upon the channel forming apparatus in order to form the sloping surfaces in the interior of the manhole base adjacent to the invert being formed. The nature of the method steps necessary for forming an invert in accordance with the abovementioned conventional technique in the manhole assembly base member is such that the operation is tedious, complex and time-consuming and also fails to provide accurate alignment between the invert and the sidewall openings to assure smooth flow through the manhole base and to maximize the flow rate through the manhole base.
BRIEF DESCRIPTION OF THE INVENTION
The present invention is characterized by comprising method and apparatus for forming an invert in a manhole base of a manhole assembly and which is designed to permit the manhole base to be completely, simply and rapidly formed at the factory through the use of either a single pour or double pour technique.
The single pour technique is preferably utilized to form inverts of the most typically used designs, thereby lending itself to mass production techniques. Base members are formed using the single pour method by employing mold members which form and define the base and sidewall of the manhole base. Ring-shaped gasket holder assemblies are arranged within the aforesaid mold members to form and define the openings in the manhole base sidewall into which the gaskets held thereby are integrally cast. The manhole base is cast in an "upside-down" fashion. The mold member forming part of the mold assembly is provided with a channel shaped projection for forming and defining the invert and is provided with flange portions each defining a recess arranged between the outer end of the invert and its associated sidewall opening, which recesses facilitate insertion of a connecting pipe. The mold member having the channel shaped projection is provided with reciprocally movable registration pins insertable into associated locater openings provided in the ring shaped gasket supports so that, when the aforesaid mold member is in position and the registration pins are inserted into their associated locater holes, precise alignment of the invert with the associated sidewall openings is thereby assured. The casting material is then poured into the molding apparatus.
When the cast member has set, the mold members, including the mold member utilized to form the invert, are separated from the cast member. The registration pins are withdrawn from the locater openings to facilitate removal of the invert forming mold member. The ring-shaped gasket holders are likewise disassembled and removed, thereby forming a manhole base having sidewall openings integrally formed with pipe sealing gaskets and having an invert whose longitudinal axis is precisely in coaxial alignment with the central axis of the adjacent side wall opening. The recesses arranged between the outer ends of the invert and the adjacent side wall opening provide for either misalignment of a pipe extending therethrough to facilitate insertion of a pipe as well as allowing for misalignment of the pipe relative to the longitudinal axis of the invert which may, for example, occur due to settling of the earth about the manhole assembly, as well as other natural phenomena. The gaskets provide an excellent water-tight seal between the pipe and the manhole base sidewall, once the pipe is inserted while at the same time being sufficiently resilient to facilitate simple and yet rapid initial insertion of the pipe end.
The most widely used manhole base is comprised of a linear invert which is coaxial with an imaginary diameter of the base member, and as a result, it is practical to produce a mold member which defines the aforesaid invert due to the large number of base members normally produced through the use of such a mold member. However, a significant number of base members frequently require inverts extending between openings which are arranged to be in alignment with imaginary radii which cooperatively form an angle of other than 180°. It is thus cost-prohibitive to produce a mold member which defines an invert for each such invert configuration. As a result, the present invention further incorporates a mold member having a main body portion and a first channel-forming projection integrally formed on the main body portion and a movable channel-forming projection which is releasably secured to the main body portion. A flexible connector extends between the integral and movable channel-forming projections. Reciprocating registration pins, as were described hereinabove, are provided in the mold member and are arranged to be extended radially outward for insertion into locater openings in the gasket supporting rings to assure precise alignment between the channel-forming projections and the sidewall openings in the manhole base. The movable member of the channel forming mold member may be oriented at any desired angle relative to the integral channel-forming member over a range from 90° to 270°, for example, thereby enabling the formation of a wide variety of base members having two side wall openings. Automatically operable suction means is arranged within the movable channel-forming member to releasably secure the movable member to the main body portion, the vacuum condition being releasable upon completion of the casting and setting of the manhole base. Pneumatic means may also be provided as shown in one preferred embodiment, for operating the registration pins in a reciprocating manner.
The present invention further teaches method and apparatus for forming inverts in manhole assembly base members utilizing a two-pour technique in which the manhole assembly base is formed and cast in a first pour wherein the sidewall openings each have an integrally mounted gaskets and wherein a flat interior floor is formed in the base member during said first pour. Thereafter, two or more channel-forming projection members and cooperating alignment rings are inserted into the manhole assembly base member and the alignment rings cooperating with clamping members secure the channel-forming members to the base member at each sidewall opening and further assure precise axial alignment between each sidewall opening and its associated channel-forming member. Once the channel-forming members are so mounted, they are generally axially aligned along imaginary radii of the manhole assembly base member. Each channel-forming member is provided with a planar top surface having an upwardly extending elongated projection. Clamping bars are provided to clamp the inwardly directed ends of the channel-forming members to one another to assure precise angular alignment therebetween and further to assure alignment of the channel-forming members so that their longitudinal axes lie in a common imaginary plane. The clamping bars may be comprised of a pair of operating clamping members arranged so that the first ends of the clamping bars cooperate with fastening means to arrange the clamping bar members at any desired angle therein. The clamping members, once arranged to obtain the desired angle, are then clamped to projections on respective ones of the channel-forming members for securement thereto, whereupon the "second-pour" of the casting operation is then initiated, the casting material being poured into the interior of the manhole assembly base member and about the channel-forming members. After the casting material is poured, but before it is set, the operators slope the floor of the base member on opposite sides of the invert. Once the casting material is set, the channel-forming projections and clamping members may then be removed, completing the two pour operation.
The two pour operation is ideal for use in forming manhole assembly base members having two or more openings and cooperating inverts. In manhole bases in which at least two sidewall openings are provided, the channel-forming members for forming two of the invert portions are preferably joined with an intermediate flexible member, as was described hereinabove. The two pour method is especially advantageous for use in forming inverts in manhole assembly bases having one or more sidewall openings, especially three such openings, the channel-forming members being adapted to be arranged at any desired angle to thereby form associated invert portions which are in precise axial alignment with their adjacent sidewall openings to assure smooth, non-turbulent flow through the base member.
Another preferred embodiment of the present invention comprises a resilient, flexible shell defining first and second channel-forming assemblies joined together by a flexible duct enclosed within the resilient flexible shell. The opposite ends of the flexible duct are respectively joined to first and second internal supporting structures. A flexible leaf spring extends through the flexible duct to permit flexing in a horizontal plane while preventing flexing in the vertical plane.
Anti-flotation bars extend over a portion of the top surface of said resilient, flexible shell and prevent the flotation of the invert form due to the casting material pouring into the manhole base. The anti-flotation bars are adjustable to permit angular orientation of the invert form within the manhole base for forming a sloping invert. The leaf spring cooperates with the anti-flotation bars to prevent flotation and to assure the formation of an invert having a perfectly linear slope from the higher sidewall opening to the lower sidewall opening (or openings).
The resilient, flexible invert is formed by placing the internal supporting structures and flexible duct into a mold having a predetermined contour, typically for forming an invert of a nominal angle of 180°, 135° or 90° and pouring the material used to form the shell into the mold so that the material covers the flexible duct and substantially covers the internal supporting structures. An anti-flotation bracket is used to prevent flotation of the flexible duct when the shell forming material is poured into the mold. The completed invert retains its nominal contour and is sufficiently flexible to be deflected to any angle within the range of the order of 20° to 35° from its nominal contour. A flexible leaf spring member extending the flexible duct enhances the resiliency of the invert form.
The flexible duct significantly reduces the amount of material required to form the shell and hence significantly reduces the weight of the invert form. The flexible duct assures the formation of a shell having a thickness which is controlled to prevent creasing or folding of the shell along the inside curve and to prevent creasing or permanent deformation of the shell.
The flexible resilient invert form can be used for the single-pour, as well as the two pour methods. The two pour method has been described hereinabove. The single pour method comprises the step of securing one of the internal supporting structures to the body member of the single pour molding apparatus, as will be more fully described.
OBJECTS OF THE INVENTION AND BRIEF DESCRIPTION OF THE FIGURES
It is, therefore, one object of the present invention to provide novel method and apparatus for forming manhole assembly bases having an invert which is in precise alignment with the associated sidewall openings.
Still another object of the present invention is to provide novel method and apparatus for forming manhole assembly bases in which the manhole bases, sidewall openings and cooperating inverts are all formed during a simplified single pour operation.
Still another object of the present invention is to provide novel method and apparatus for forming inverts in manhole assembly bases which include means for simply and yet precisely aligning the invert forming apparatus with the associated sidewall openings.
Still another object of the present invention is to provide novel apparatus for forming inverts in manhole assembly bases in which the channel-forming members provided to form and define the inverts may be arranged at any desired angle and yet precisely aligned with the associated sidewall openings.
Still another object of the present invention is to provide apparatus for forming inverts in manhole assembly bases and the like in which the channel-forming members forming said invert are joined by a flexible coupling means.
Still another object of the present invention is to provide a manhole base provided with recesses arranged between each sidewall opening having a sealing gasket and the adjacent end of an invert for facilitating insertion of a pipe in sealing relation.
Another object of the present invention is to provide a resilient, flexible invert form for producing inverts and being sufficently resilient and flexible to enable deflection of the invert form from its nominal contour to enable formation of inverts over a wide range of contours.
Another object of the invention is to provide a novel method for producing flexible, resilient invert forms.
Another object of the present invention is to provide a novel method for producing invert forms having a flexible, resilient shell enclosing a flexible duct joined at its ends by internal support structures adapted to join and align the invert form with the sidewall openings in a manhole.
Another object of the invention is to provide a flexible, resilient invert form of the character described and having anti-flotation bars to prevent flotation of the invert form due to the casting material.
The above, as well as other objects of the present invention, will become apparent when reading the accompanying description of the drawings in which:
FIG. 1 is an exploded perspective view of the molding apparatus employed for forming a manhole assembly base member in accordance with the single pour technique.
FIG. 1a shows a perspective view of the channel-forming member showing the gasket supporting rings, inner cylindrical mold member and wire frame of FIG. 1 assembled upon the bottom plate.
FIGS. 2a and 2b show perspective views of the top and bottom sides respectively of the channel-forming member of FIG. 1a.
FIG. 2c shows a sectional view of a portion of the channel-forming member looking in the direction of arrows 2c--2c in FIG. 2a.
FIG. 3a shows a top plan view of a manhole assembly base member formed through the use of the single pour technique and employing the apparatus of FIG. 1.
FIG. 3b shows a perspective view of the manhole assembly base member of FIG. 3a with a portion thereof being removed for purpose of exposing the interior construction.
FIG. 3c shows a sectional view of one of the sidewall openings of FIG. 3b looking in the direction of arrows 3c--3c.
FIG. 3d shows a top plan view of still another manhole base.
FIG. 4 shows an exploded perspective view of the molding apparatus employed for forming a manhole assembly base member in accordance with the two pour technique.
FIG. 5 shows a perspective view, partially sectionalized, of the manhole assembly base member cast through the use of the apparatus of FIG. 4.
FIG. 6 is an exploded perspective view of the apparatus employed for forming a portion of the invert in the base member of FIG. 5.
FIG. 6a shows an exploded perspective view of an alternative clamping bar assembly which may be employed in place of the clamping bar shown in FIG. 6.
FIG. 6b shows a sectional view of the adjustable portion of the clamping bar assembly of FIG. 6a.
FIGS. 7a and 7b are front and sectional views respectively of the positioning ring of FIG. 6.
FIGS. 8a and 8b are perspective and front elevational views respectively of the channel-forming member of FIG. 6.
FIG. 9 is a perspective view showing channel-forming assemblies of the type shown in FIG. 6, fully assembled within a base member in readiness for the second pour of the two pour method.
FIG. 10 shows a perspective view, partially sectionalized, of the base assembly of FIG. 9 after the invert has been case and set.
FIG. 11 is a perspective view of an assembly for forming an invert within a manhole assembly base member in accordance with the two pour technique for use in base members having large diameter sidewall openings.
FIG. 12 is a perspective view of another alternative embodiment of the invert forming mold member of FIG. 1.
FIG. 12a shows a sectional view of a portion of the invert forming mold member of FIG. 12 looking in the direction of arrows 12a--12a.
FIG. 12b shows a sectional view of a portion of the invert forming mold member of FIG. 12 looking in the direction of arrows 12b--12b.
FIG. 12c shows an elevational view, partially sectionalized, of the invert forming mold member of FIG. 12.
FIG. 13 is a perspective view of an alternative embodiment for the invert forming mold assembly of FIG. 6 employed for forming base members in accordance with the two pour technique.
FIG. 13a is a perspective view of one of the invert forming members of FIG. 13 showing the manner in which a clamping bar is arranged thereon.
FIG. 13b shows a sectional view of a portion of the invert forming assembly of FIG. 13 looking in the direction of arrows 13b--13b.
FIG. 14 shows a perspective view, partially sectionalized, of a manhole assembly base and showing the manner in which an invert forming assembly of the type shown in FIG. 13 is mounted therein preparatory to casting the invert within said manhole base.
FIGS. 15 through 19 show another embodiment of the invention, in which:
FIG. 15 is a perspective view of the completed invert form.
FIG. 16 is an exploded perspective view of the internal structure of one end of the invert form of FIG. 15.
FIG. 16a is an enlarged elevational view of a portion of the internal structure of FIG. 16 and which is partially sectionalized.
FIG. 17 is a perspective view of a portion of the mold used for producing the invert form of FIG. 15.
FIG. 17a is a detailed elevational view of the antiflotation structure used with the mold of FIG. 17.
FIG. 18 is a perspective view showing an invert form of the type shown in FIG. 15 arranged in a manhole base.
FIGS. 19a to 19d are plan views showing four different invert forms embodying the principles of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 shows an exploded perspective view of the molding apparatus 10 employed for forming a manhole assembly base member in accordance with the single pour technique. The molding apparatus 10 is comprised of a disc-shaped member 22 having an outermost periphery 22a adapted to be received within the interior of the lower edge of sidewall 12a of the outer cylindrical mold member 12. The outer cylindrical mold member 12 defines the exterior wall of the manhole base. The manhole base is cast "upsidedown" as will be described in detail hereinbelow. Outer cylindrical mold member 12 is provided with a pair of collars 15, 15 swingably mounted to the exterior of outer cylindrical mold member 12 by fastening pins 13, 13. Collars 15, 15 are each provided with a short section of chain 15a, 15a to receive hooks (not shown) from an overhead crane, for example, for lifting and rotating the molding apparatus 10 as will be more fully described.
Cylindrical shaped inner mold member 18 is provided with a hinge assembly 19 for respectively increasing or reducing the diameter of the cylindrical inner mold member 18 for a purpose to be more fully described. The hinge assembly 19 is initially arranged to increase the diameter of the cylindrical inner mold member to properly position member 18 upon member 22, so that the cylindrical periphery 22e extends into the interior of mold member 18 and engages the inner periphery thereto, whereby lower edge 18a rests upon surface 22d of member 22.
The wire reinforcement frame 20 is arranged between inner mold member 18 and outer mold member 12 so that its lower edge rests upon surface 22d. Frame 20 is comprised of a plurality of vertically arranged wires 20a and horizontally aligned circular-shaped wire loops 20b which define the wire frame 20 to form a reinforcing frame which is molded into the interior of the cast manhole base, as will be more fully described. The wire frame 20 is bent to form openings 20c and 20d for receiving the gasket retainer assemblies 16, 16.
The mold member 14 which forms and defines the invert in the manhole base is comprised of a main body portion 14a having sloping surfaces 14b and 14c arranged on opposite sides of the generally cylindrical shaped invert forming projection 14d. Flange-like portions 14e and 14f arranged at the ends of a substantially cylindrical shaped projection 14b form recesses within the interior of the manhole base to facilitate insertion of connecting pipes, as will be more fully described. Registration pins 14g and 14h reciprocally mounted within the body of member 14 are arranged to be respectively moved so as to extend outwardly from the ends of projections 14d or to be drawn inwardly for purposes to be more fully described.
FIGS. 1 and 2a through 2c show the invert forming mold member 14, which is provided with a guideway 14j slidably receiving and mounting registration pin 14h. An elongated projection 14k is integrally joined to the inner end of registration pin 14h. Projection 14k extends downwardly through an elongated slot 14l provided in the underside 14m of body member 14a. A similar slot 14n is provided for projection 14p which is integrally joined to the inner end of registration pin 14g. Projections 14k and 14p are reciprocally movable as shown by double-headed arrows A1 and A2, in order to respectively extend and withdraw their associated registration pins 14h and 14g. Projections 14q and 14r, extending downwardly from the underside of mold member 14, serve as alignment means for aligning member 14 upon the inner cylindrical mold member 18.
FIG. 1a shows a sub-assembly of the casting apparatus 10 of FIG. 1 wherein the inner cylindrical mold member 18 is shown having its lower edge supported upon disc-shaped member 22. The reinforcing frame 20 has its lower edge supported upon disc-shaped member 22 and surrounds inner cylindrical mold member 18. The projections 14k and 14p, which extend downwardly and into the interior of inner cylindrical mold member 18, are moved radially outward so that their associated pins 14h and 14g extend outwardly from the end surfaces 14f-1 and 14e-1 of the mold member 14. The registration pins 14h and 14g extend into the openings 16b, 16b of the gasket retainer ring assemblies 16, 16. The gasket retainer assemblies are comprised of inner and outer ring members 16a, 16b, arranged to sandwich a gasket 17 therebetween. Note especially the left-hand ring assembly of FIG. 1. The aforesaid gasket 17 is also shown in FIG. 3c in sectional fashion. Ring members 16a, 16b have been shown in dotted fashion in FIG. 3c. As can best be seen from the last-mentioned figure, the inner or substantially D-shaped portion 17a of the gasket 17 is sandwiched between inner and outer ring members 16a and 16b. The substantially T-shaped portion 17b of gasket 17 extends radially outward from the ring members 16a and 16b and is adapted to be embedded within the casting material, as will be more fully described. Releasable fastening means (not shown for purposes of simplicity) are utilized to secure ring members 16a and 16b to one another and to firmly secure gasket 17 thereto.
The outer cylindrical mold member 12 is then lowered upon the sub-assembly of FIG. 1a, thereby completing the assembly of the mold members utilized to cast a manhole assembly base. The casting material is then deposited into the inner upper end of outer cylindrical mold member 12, the casting material being deposited by gravity so as to fall in the direction of arrow A3 shown in FIG. 1, thereby filling the region defined by the lower inner periphery of mold member 12 and the outer periphery of mold member 18 to form the sidewalls of the cast member and further being deposited upon the upper surface of mold member 14. The mold assembly 10 is filled to a level substantially flush with the top edge 12c of outer cylindrical mold member 12, and is thereafter allowed to set. In order to reduce the time required for the casting material, which is preferably concrete, to set, the entire casting apparatus 10 of FIG. 1 is enclosed within a shroud or housing (not shown) and steam is introduced into the last-mentioned shroud to raise the temperature level of the casting material and thereby speed up the casting operation.
The gasket mounting assemblies 16, 16 are pressed against the interior wall of outer cylindrical mold member 12 and against a portion of the outer periphery of the inner cylindrical mold member 18 in order to form and define the sidewall openings.
After the casting material has been set, the entire assembly is lifted by coupling a pair of hooks (nor shown) from an overhead crane (not shown) to the chains 15a, 15a, and the entire assembly is partially lifted off the ground and is rotated about collars 15, 15, so as to turn the entire assembly upside-down, after which the disc-shaped member 22 and the outer cylindrical mold member 12 are lifted upwardly and away from the cast manhole base. The clamping assembly 19 is manipulated to cause the marginal portions of the vertical ends 18b and 18c to overlap one another in order to reduce the outer diameter of inner cylindrical mold member 18, thereby enabling the inner cylindrical member 18 to be lifted out of the interior of the cast manhole base.
Thereafter, the elongated projections 14k and 14p are moved radially inwardly, i.e. toward one another, in order to withdraw the pins 14h and 14g from the gasket retaining assemblies, 16, 16. The mold member 14 is then lifted out from the interior of the cast manhole base.
Thereafter, the fastening means (not shown for purposes of simplicity) securing the ring-shaped halves 16a and 16b of each gasket retainer assembly 16, are loosened and then disassembled in order to remove the gasket retainer assemblies 16, 16 from the sidewall openings formed thereby. The gasket supporting assembly and gasket employed in the present invention are described in U.S. Pat. Nos. 3,796,406; 3,813,107; and 3,832,438, the aforesaid patents being assigned to the assignee of the present invention, and their teachings being incorporated herein by reference thereto.
FIGS. 3a through 3c show the cast manhole base 30 resulting from the casting operation employing the apparatus 10 of FIG. 1, said cast manhole base 30 being comprised of a base portion 31 and an integral, upwardly extending cylindrical shaped sidewall 32 terminating in a step-like ledge 33.
The sloping surfaces 14b and 14c of mold member 14 form the sloping interior surfaces 34a and 34b of base member 30, said surfaces sloping downwardly toward invert 35 formed by the substantially cylindrical shaped projection 14d, forming an integral part of mold member 14. Surfaces 14b and 14c cause liquids on surfaces 14b and 14c to run back into invert 35.
Flange portions 14e and 14f form and define the recesses 36a and 36b which are substantially semi-circular shaped recesses arranged between the outer ends of invert 35 and the associated sidewall openings 38 and 39. As can best be seen in FIG. 3c, sidewall opening 38 has a tapered portion 38a which tapers inwardly toward gasket 17, and a tapered portion 38b which tapers outwardly away from gasket 17 and which substantially merges with the outward radial end 36a-1 of recess 36a. The D-shaped portion 17a of gasket 17 can be seen to have a hollow interior portion 17a-1, which enables the gasket to be compressed upon insertion of a connecting pipe. The gasket 17 serves as a pipe-to-manhole seal. Joint assembly is quick and easy. The end 41a of pipe 41, as shown in dotted fashion in FIG. 3a, is coated with a suitable lubricant and is pushed into the sidewall opening 38a. The gasket 17 provides a compression-type joint with no moving parts and the simplicity of the joint assembly eliminates both human error and the problems inherent in rigid joints. The retainer rings 16, 16 hold the gaskets 17, 17 in a shape which precisely conforms to the curvature of the openings 38 and 39. Gaskets 17 provide a positive watertight seal and, together with its associated recess, for example recess 36a, provide at least 10° of omni-directional deflection of pipe 41 relative to the longitudinal axis 43 of the manhole base 35. As is typical in the installation of the pipe 41, the end of the pipe 41 remote from end 41a is coupled to an adjacent pipe after first installing end 41a into manhole base 30. The pipe 41 is typically arranged at an angle θ relative to longitudinal axis 43 until its end 41a is moved into sidewall opening 38 by an amount sufficient to cause its end remote from end 41a to clear the end of the pipe (not shown) to which it is to be subsequently joined, whereupon the pipe 41 may then be moved so that its longitudinal axis 44 is brought into coincidence with longitudinal axis 43. Thus, the recesses 36a and 36b provide the valuable function of facilitating insertion of each pipe, such as pipe 41, into its associated sidewall opening, such as opening 38.
The registration pins 14g and 14h which cooperate with the central openings 16c in the gasket retaining assemblies 16, 16 assure precise alignment between sidewall openings 38 and 39 and invert 35, thereby assuring smooth, non-turbulent flow of liquid matter as the liquid matter transfers from the incoming pipe 41 to the invert 35 and from the invert 35 to the outgoing pipe 45. The casting operation described hereinabove also enables the manhole base 30 and the invert 35 to be formed in a single operation and at the same site, preferably the factory site, thereby significantly increasing productivity and reducing production costs, as well as providing a more uniform product.
The casting apparatus described hereinabove in connection with FIGS. 1 through 3c is extremely advantageous for use in standardized manhole bases. For example, the manhole base 30 shown in FIGS. 3a-3c has a linear invert 35 extending along an imaginary diameter 43 of the manhole base 30. This invert configuration 35 is utilized in a vast majority of applications making it practical to design and produce a mold member of the type shown as mold member 14. However, in situations where manhole bases having non-standard sidewall openings and accompanying inverts are required on a less frequent basis or in small quantities which do not warrant the above mass production techniques, but nevertheless should be of the same accuracy and precision design, an alternative design may be used in conjunction with all of the techniques as will be described hereinbelow.
In order to form manhole bases in accordance with the single-pour technique in which sidewall openings may be arranged at angular orientations other than that shown in FIG. 3b, the mold member 50 shown in FIGS. 12 through 12c may be used in place of the mold member 14 shown in FIGS. 1 and 2a through 2c.
Mold member 50 is comprised of body portion 52 having sloping sidewalls 52a and 52b similar to the sloping sidewalls 14b and 14c of mold member 14 shown, for example, in FIG. 2a. The invert forming projection of mold member 50 is comprised of a stationary portion 54 integrally joined to body portion 52 and having a recess forming flange 56 at its outer end, flange 56 being substantially the same as flange 14f shown, for example, in FIG. 2a.
The invert forming projection is further comprised of a movable invert portion 58 of substantially cylindrical shape and having an outward radial end provided with a recess forming flange 60 which is substantially the same as flange 14e shown, for example, in FIG. 2a. Flanges 56 and 60 are designed to form the recesses such as, for example, the recesses 36b and 36a of manhole base 30, shown in FIGS. 3a-3d. Registration pins 62 and 64 are reciprocally mounted in a manner similar to registration pins 14g and 14h of mold member 14 shown, for example, in FIGS. 2a and 2b and are operated in a manner to be more fully described.
A sectional view of invert forming member 58 is shown in FIG. 12a and this invert forming member can be seen to be hollow and has a substantially semi-oval shape. The lower edges 58a and 58b are positioned just above the top surface of body member 52. Channel-shaped resilient sealing gaskets 66, 66, are fitted about the lower edges 58a, 58b, to provide a resilient mount for supporting edges 58a, 58b on the top surface of body member 52 and to prevent casting material from entering into the region between projection 58 and the top surface of body member 52. A supporting assembly comprised of brackets 68a, 70, 72 and 74 have their outer ends secured to the interior surface 58c of invert forming portion 58 and have their opposite ends secured by suitable fastening means 76, 78 to a vacuum grip assembly 80 comprised of a resilient, compressible, substantially bell-shaped member 82 and a pumping assembly 84 having a reciprocating, manually manipulatable operating button 86 which, when repeatedly depressed and released, draws a vacuum in the interior region defined by bell-shaped member 82 and the top surface of body portion 52, thereby firmly mounting invert forming member 58 upon the surface of body member 52. The movable invert forming member 58 can thereby be seen to be capable of being positioned at any suitable angle relative to invert forming portion 54 and is capable of being swung about an imaginary central axis represented by dotted line 88, in either the clockwise or counter-clockwise direction, as shown respectively by arrows A5 and A6. When it is desired to release the invert forming portion 58 from body portion 52, release arm 90 of vacuum grip assembly 80 is depressed, rotating arm 90 in the clockwise direction, as shown by arrow A6 about pivot pin 91, causing the vacuum condition to be interrupted and allowing air at atmospheric pressure to be introduced into the hollow region between bell-shaped member 82 and the top surface of body portion 50, thereby releasing the vacuum grip assembly 80 and hence the invert forming portion 58 from body portion 52.
A sectional view of the invert forming portion 54 looking in the direction of arrows 12b-12b, is shown in FIG. 12b. The lower edges 54a and 54b are secured to the top surface of body portion 52 for example, by weldments W, W. A flexible invert forming portion 94 is arranged to span between invert forming portions 54 and 58 as can best be seen in FIGS. 12 and 12c, and is preferably formed of a rugged cloth or cloth-like material 96 which may be in the form of a wide band wrapped in an overlapping helical fashion so as to embed a preferably continuous, helically-wound supporting wire 98, to form flexible ducting 94 which, in most applications, is typically provided with a circular cross-sectional configuration. The flexible ducting assembly 94 of the present invention, however, is provided with a substantially D-shaped cross-sectional configuration defined by a generally semi-circular portion 94a and a linear surface portion 94b, shown best in FIG. 12b.
Both ends of flexible ducting assembly 94 are reinforced by D-shaped reinforcing frames 100 and cooperating straps 102. Since both reinforcing arrangements at both ends of flexible ducting 94 are substantially identical only one has been shown for purpose of simplicity. As shown in FIG. 12b, rigid D-shaped reinforcing frame 100 is positioned within the interior of flexible ducting assembly 94 and adjacent the right-hand end thereof (relative to FIG. 12). A linear strap 102 is positioned along the exterior surface of planar surface portion 94b. Strap 102 and D-shaped reinforcing member 100 are retained in position by fastening assemblies 103 and 104 which secure member 100 to member 102 and which sandwich the planar portion 94b of flexible ducting assembly 94 therebetween. The right-hand end 94c of flexible ducting assembly 94 is preferably force-fittingly inserted into the hollow region defined by the interior of the left-hand end 54d of invert forming portion 54 and the top surface of body portion 52. As was described hereinabove, the left-hand end 94d of flexible ducting assembly 94 is provided with a similar D-shaped reinforcing member 100 and strap 102 and similarly is preferably force-fittingly inserted between the interior surface of invertforming portion 58 and the top surface of body portion 52. Obviously, if it is desired to permanently secure flexible ducting portion 94 to invert forming portions 54 and 58, this may be accomplished for example, by providing suitable fastening means.
FIG. 12c shows an arrangement in which the registration pins 62 and 64 and the vacuum grip assembly 80 may be operated from a remote source. As shown in FIG. 12c, the manually operable vacuum grip assembly 80 is replaced by a vacuum grip assembly 80' secured to the interior of invert forming portion 58 by similar bracket means for example, by bracket member 68. Bell-shaped member 82 is coupled to a remote vacuum/pressure source, (not shown for purposes of simplicity) by means of conduit 107 to draw a vacuum in the interior region defined by bell-shaped member 82 and the top surface of body portion 52. The vacuum condition is selectively released by introducing air of at least atmospheric pressure into the aforesaid hollow interior region when it is desired to reposition invert forming portion 58.
Registration pins 62 and 64 may be reciprocally operated to be selectively moved in the directions shown by double headed arrows A8 and A9 by means of piston assemblies 110 and 112, each communicating with a remote vacuum/pressure source (not shown) by means of a common conduit 114 communicating with piston cylinders 110 and 112 by means of branch conduits 114a and 114b.
By introducing air under pressure into conduit 114, the piston members 110a, 112a, are moved in the outward radial direction causing the piston rods, which in actuality are registration pins 64 and 62, to move radially outward for insertion into the cooperating central openings in. the gasket retaining assemblies 16, 16 shown for example, in FIG. 1.
By coupling conduit 14 to a vacuum source, pistons 110a, 112a may be drawn radially inwardly and toward one another to draw pins 64, 62 into the interior of the invert forming portions 58 and 54, thereby automating these operations.
A manhole base is formed in accordance with the single-pour technique and utilizing the mold forming member 50, in a manner substantially similar to the technique described in connection with the apparatus 10 of FIG. 1 except that the movable invert forming portion 58 is positioned at the desired angle relative to invert forming portion 54. Flexible ducting assembly 94 is adapted to flex and form a smooth curved portion intermediate the inner ends of invert forming portions 54 and 58 thereby forming a continuous invert forming assembly defined by portions 54 and 58, and the flexible ducting 94 arranged therebetween.
Once movable invert forming member 58 is properly positioned, a vacuum condition is drawn by the vacuum grip assembly 80, or 80', to firmly secure invert forming portion 58 in the proper angular alignment relative to stationary invert forming member 54.
Thereafter, the invert forming member 50 is positioned upon the inner cylindrical mold member 18 shown in FIG. 1a, in place of the mold forming member 14. Obviously, the horizontally aligned wires 20b are bent in the manner shown in FIG. 1 at the proper angular orientations so as to coincide with the positions occupied by the outer ends of invert forming members 54 and 58. Thereafter, all of the mold forming steps are identical to those described hereinabove in connection with FIG. 1 to form a manhole base utilizing the single pour technique. The invert formed thereby will be provided with two substantially linear invert portions 35' and 35" and a curved, intermediate portion 35'", as shown best in the manhole base 30' of FIG. 3d. The remaining advantageous features and characteristics of manhole base 30' are substantially identical to those described in connection with the manhole base 30 of FIGS. 3a through 3c.
The two pour technique may be employed in place of the single pour technique and is further uniquely advantageous for use in forming manhole bases having more than two sidewall openings. The first stage of the two pour technique is performed through the utilization of the casting apparatus 10' of FIG. 4 which is substantially identical to the casting apparatus 10 of FIG. 1, except that the mold member 14 provided in the apparatus 10 of FIG. 1 is not used in the two pour technique. More particularly, outer cylindrical mold member 12 is shown positioned upon disc-shaped member 22. Inner cylindrical mold member 18, although shown in exploded fashion, is also supported upon disc-shaped member 22 and is further provided with a closed top surface 18d. Wire reinforcing frame 20 is likewise positioned upon disc-shaped member 22 and the horizontally aligned wires 20b are bent to form openings 20c and 20d to receive the gasket retaining assemblies 16, 16.
In the absence of mold member 14, gasket retaining assemblies 16, 16, are properly positioned and secured in the desired position by threaded members T1, T2, which extend through openings 12d and 12e in outer cylindrical mold member 12, in order to threadedly engage openings 16c, 16c which are tapped to provide a threaded engagement with threaded fastening members T1 and T2. The threaded fastening members are provided with enlarged flange portions T1a and T2a which rest against the exterior surface of outer cylindrical mold member 12 so that when tightened, the threaded fasteners T1 and T2 cause the adjacent edges of retainer members 16a, 16a, to be firmly urged against the interior surface of outer cylindrical mold member 12. Once the above-mentioned mold members of casting apparatus 10' are fully assembled, the casting operation is begun. The manhole base is cast "upside-down". The hollow interior region between the exterior surface of inner cylindrical mold member 18 and the interior surface of outer cylindrical mold member 12 form and define the sidewalls of the manhole base. The remaining interior region between the closed end 18d of mold member 18 and the mold member 12 extending thereabove form and define the bottom of the manhole base.
After the casting material has been poured into the mold apparatus, the casting material is allowed to set. To facilitate the setting of the casting material, the molding apparatus 10' may be covered with a housing or shroud (not shown for purposes of simplicity). Steam under pressure is then introduced into the shroud to raise the temperature level of the casting material and thereby accelerate the setting of the casting material.
Once the casting material has been set, hooks (not shown) coupled to an overhead crane (not shown) are connected to chains 15a, 15a, to lift the entire casting apparatus 10'. The apparatus 10' is lifted a distance above the ground sufficient to allow the entire casting apparatus to be turned "rightside-up", the casting apparatus being swung about the central axis of collars 15, 15. After being turned over, the casting apparatus 10' is then set upon the ground and threaded fasteners T1 and T2 are removed. The inner and outer mold members are then removed and the fastening means (not shown) coupling the gasket retaining members 16a and 16b of each gasket retaining assembly 16 are removed to remove member 16a and 16b from each of the sidewall openings which they form and define, thereby completing the casting operation.
Although the example of FIG. 4 shows a molding apparatus for forming a manhole base having two sidewall openings, it should be understood that three or more sidewall openings may be formed through the use of the apparatus 10' of FIG. 4, and through the use of additional gasket retaining assemblies 16 and threaded fastening members T, as well as appropriate openings provided in the sidewall of outer cylindrical mold member 12 to position and secure the gasket retaining members at desired locations.
FIG. 5 shows a manhole base 120 formed through the use of the molding apparatus 10' shown in FIG. 4, and being comprised of a bottom portion 122 and integral upwardly extending sidewall 124 having openings 126 and 128, each provided with a resilient compressible gasket 130 and 132, respectively. The step-like upper edge 134 is designed to receive and support a complementary step-like lower edge of an intermediate or riser member of a manhole assembly (not shown), as in conventional in manhole assembly technology.
The interior floor 136 of manhole base 120 is substantially flat and is positioned well below the lower ends of the sidewall openings 126, 128.
The second phase of the two pour technique, i.e. the formation of the invert, is performed through the use of the apparatus 140 shown in FIGS. 6 through 8b and comprised of an invert forming member 142 having a substantially cylindrical shaped portion 142a, a planar upper surface 142b, having an elongated flat bar 144 integrally joined thereto and having a substantially semi-circular shaped recess forming flange portion 142c provided at one end thereof and adapted to form the recess arranged between the outer end of the invert and the adjacent sidewall opening, such as for example the recesses 36a and 36b shown in FIG. 3a, and the recesses to be described hereinbelow in connection with FIG. 10.
Flange portion 142c has a planar end surface 142d provided with a tapped opening 142e which is coaxial with the longitudinal axis of semi-cylindrical portion 142a.
Dish-shaped registration member 146 forming part of the invert forming assembly 140 is comprised of a centrally located disc-shaped portion 146a and an integral flange 146b sloping outwardly therefrom. The disc-shaped central portion 146a has a curvature conforming to the curvature of gasket 17. A centrally located opening 146c is provided in disc-shaped portion 146a.
Dish-shaped registration member 146 is press-fitted into opening 126, so that the exterior surface of flange 146b rests upon tapered surface 126a of opening 126 and so that the marginal portion of disc-shaped central portion 146a rests against the right-hand surface 17f and conforms with the curvature of gasket 17.
An elongated threaded rod 148, also forming part of the invert forming apparatus 140, is extended through opening 146c and threadedly engages tapped opening 142e. The left-hand end of threaded rod 148 extends through an elongated slot 150a in rigid elongated plate 150 which is positioned to span opening 126 and rest against the exterior surface of sidewall 124. Elongated threaded rod 148 has a length sufficient to extend through elongated slot 150a. A butterfly fastener 152 is threaded on to the left-hand end of rod 148 and is adequately tightened an amount sufficient to cause dish-shaped registration member 146 to be pressed firmly against gasket 17 and to cause invert forming member 142 to be tightly drawn against dish-shaped registration member 146.
Opening 146c is located along an imaginary axis 154 which is precisely aligned with and passes through the center of opening 126, which is also the center of gasket 130. Opening 142e in member 142 is also coincident with imaginary axis 154 which coincides with the longitudinal axis of the invert forming portion 142a. By interconnecting all of the components of the invert forming assembly 140 shown in FIG. 6, precise alignment between the portion of the invert formed by member 142 and sidewall opening 126 is simply and yet positively assured.
An assembly substantially identical to the invert forming assembly 140 of FIG. 6 is secured in place in each of the sidewall openings 126 and 128. Obviously in embodiments in which three or more sidewall openings are provided, an appropriate number of assemblies 140 is provided for each such sidewall opening.
FIG. 9 shows a manhole base 120' substantially similar to the manhole base 120 of FIG. 5 and having three sidewall openings, each having an invert forming assembly 140, 140' and 140" mounted thereto in the manner described hereinabove in connection with FIG. 6.
In order to be assured that each of the assemblies 140 through 140" have their interior ends in the proper angular orientation and to further assure that the invert forming members 142, 142' and 142" are horizontally aligned, i.e. have their upper surfaces 142b, 142b' and 142b" lying in a common imaginary horizontal plane, elongated rigid bars are clamped in place to obtain such alignment. For example, FIG. 6 shows an elongated rigid bar 156 bent at 156a so that two straight portions 156b and 156c form an angle Φ which angle is precisely the desired angle to be formed between the invert forming portions so joined. Straight portion 156b is placed against elongated projection 144 and with its lower edge 156b-1 resting against planar top surface 142b. Suitable clamping means, such as, for example, the clamping means C1 and C2, are utilized to retain the portion 156b of bar 156 in position relative to elongated projection 144 and hence member 142. The remaining half 156c of bar 156 is placed against projection 144' of assembly 140' and resting on surface 142b ' and is similarly clamped into place by clamping members C3 and C4. This technique assures that the top surfaces 142b and 142b' of members 142 and 142' lie in a common horizontal plane, further assuring precise alignment and accurate registration as between the invert to be formed thereby and the associated sidewall openings in the manhole base 120'.
Precise alignment and orientation of invert forming assembly 140" is accomplished in a similar manner by utilization of a bent bar 156' having its linear portion 156a' clamped to projection 144" by clamping means C5 and C6 and having its linear half 156b' clamped to projection 144' by clamping means C4.
When the assemblies shown in FIG. 9 are fully assembled and interconnected to one another in the manner described hereinabove, the casting material is poured into the interior of manhole base 120' to fill the interior thereof to the proper height. The sloping surfaces surrounding the invert are manually shaped and formed by operators as the casting material is poured into manhole base 120'. The center portion 160d of the invert in the region of the gap G between the inner ends of the invert forming assemblies 140, 140' and 140" is manually formed by the operators during the casting operation. After the casting material has been poured and allowed to set, the assemblies 140, 140' and 140" are disassembled and removed from manhole base 120'. The completed manhole base 120" is shown in FIG. 10 as having an invert defined by three invert portions 160a, 160b and 160c. The flanges such as, for example, the flange portion 142c of FIGS. 6 and 8a, form the recess portions 162, 164 and 166 positioned between the outer end of each invert portion 160a, 160b and 160c and the associated sidewall opening 168, 170 and 172 respectively.
FIGS. 6a and 6b show a clamping bar assembly 180 which may be substituted for the clamping bar 156 shown, for example, in FIG. 6. The clamping bar assembly 180 is comprised of cooperating members 182 and 184, each being comprised of an elongated bar 182a, 184a and a dish-shaped coupling member 182b, 184b respectively, each said cup-shaped member being provided with a central opening 182b-1, 184b-1 for receiving fastening member 186 in the form of a threaded bolt adapted to threadedly engage nut 188. The exterior diagonally aligned surface portion 182b-2 of dish-shaped member 182b is knurled or otherwise roughened and the interior diagonally aligned surface 184b-3 of dish-shaped member 184b is likewise knurled or roughened and cooperates with knurled surface 182b-2 to lock the dish-shaped members 182b and 184b together when fastening members 186, 188 are suitably tightened. The dish-shaped members 182b, 184b and hence the bars 182a, 184a , may be arranged at any desired angular orientation in order to coincide with the angular orientation of the invert forming members such as, for example, member 142 in order to clamp the invert forming members at the proper angle. If desired, a marker 190 may be provided on dish-shaped member 182b and cooperating indicia may be placed about the exterior diagonally aligned surface 184b-2 to cooperate with marker 190 in order to facilitate setting of arms 182a, 184a at the desired angular orientation.
FIG. 11 shows a typical assembly 200 similar to the assembly 140 of FIG. 6 and which may be employed to form an invert in a relatively large size manhole base, the assembly 200 of FIG. 11 preferably being formed of a plastic material to minimize production costs, although any other suitable material may be employed if desired. The most prevalent size manhole base typically is designed to accomodate a pipe having an 8" outer diameter. However, manhole bases of relatively large size can be designed to accommodate a concrete pipe having an outer diameter of 2 feet or more. The invert forming assembly 200 is designed to form an invert of a very large size diameter and, as a result, is provided with a pair of dish-shaped registration members 202, 204 each adapted to be positioned within the interior half of a sidewall opening and having surfaces 202a, 204a arranged to rest against the tapered interior surface 126a of sidewall opening 126 (see FIG. 6) while the outer marginal portion of surfaces 202b, 204b are designed to rest against the surface 17f of gasket 17. As we described hereinabove, and especially due to the large diameter of the sidewall opening, each sidewall opening, such as sidewall opening 126, for example, has a curvature conforming to the radius of curvature of the manhole base gasket which conforms to the radius of curvature of the manhole base sidewall, said radius of curvature being measured in a horizontal plane which is perpendicular to the sidewall of the manhole base.
The invert defining members 206 and 208, similar to the invert defining member described in connection with FIG. 6, are each provided with a planar top surface 206a, 208a having an elongated linear projection 210, 212 and having the outer ends thereof provided with flange portions 206a, 208a for forming the aforementioned recesses arranged between the outer ends of the invert and the associated sidewall opening. The substantially semicircular shaped peripheries 206c, 208c form and define associated portions of the invert within the manhole base. The invert forming assembly 200 is mounted within a manhole base of the type shown in FIG. 9 in a manner substantially the same as and utilizing substantially the same apparatus as the invert forming assembly shown in FIG. 6. More specifically, each dish-shaped registration member 202, 204 is provided with a central opening 202c, 204c and, although not shown, the outer ends of invert forming members 206 and 208 are likewise provided with cooperating tapped openings for receiving a threaded rod such as, for example, the threaded rod 148 of FIG. 6. Openings 202c, 204c are coincident with the center of the openings 126, 128 in sidewall 124 (see FIG. 5). The openings (not shown) provided in members 206 and 208 are coincident with the longitudinal axis of the invert to be formed. These centers are simply and rapidly brought into precise axial alignment when the assembly 200 is mounted within manhole base 120 and fixedly secured in place through the additional means of the rigid plate 150 and fastener 152. As was described hereinabove, the gap G between the inner ends of members 206 and 208 is formed during the casting operation to conform to the shape of the invert by operators who remove sufficient casting material to provide the desired shape of the invert at the intermediate portion thereof. Similarly, the operators also move and/or shape the casting material in the region on opposite sides of the invert being formed to form surfaces 161a, 161b, 161c (see FIG. 10) which slope downwardly toward the invert in order to assure that any liquid falling upon such sloping surfaces flows downwardly along the sloping surfaces to be returned to the invert.
The horizontal alignment of the assembly 200 is obtained through the use of a clamping member 180 and clamping assemblies C9 and C10, by clamping member 180 to projections 210 and 212 in a manner described hereinabove in connection with the embodiment of FIG. 6. Forming the assembly 200 as shown in FIG. 11 of a suitable plastic material such as synthetic polyester, for example, greatly reduces production costs for producing assemblies 200 and yet provides apparatus which is sufficiently durable to withstand repeated use.
As was the case with the mold structure employed in the single-pour apparatus, the apparatus shown; for example, in FIGS. 6 and 11 may be modified to provide an intermediate flexible connector similar to that employed with the single-pour mold forming apparatus shown in FIG. 12 and provided for use in conjunction with the two-pour technique. For example, FIGS. 13 through 13b show invert forming apparatus 300 similar to that shown in FIGS. 6 and 11 and comprised of invert defining members 302 and 304 having planar top surfaces 302a, 304a; substantially semicylindrical invert forming surfaces 302b, 304b; elongated projections 302c, 304c; and recess forming flanges 302d, 304d. The invert forming members 302 and 304 are preferably hollow. Noting, for example, FIG. 13a, a portion of invert forming member 304 is shown therein and is provided with an open inner end 304e. A portion 304a-1 of top surface 304a is removed in order to accommodate the intermediate flexible coupling 306 comprised of a rugged and yet bendable material such as a rugged fabric 306a which is wrapped in a substantially helical fashion about a substantially helically wound wire reinforcement 306b to form a flexible duct having a planar top surface 306c and a substantially semicylindrical bottom surface 306d. The flexible ducting 306 is reinforced in the same manner as the flexible ducting 94 shown, for example, in FIG. 12b in that a D-shaped reinforcing member 308 is placed in the interior of the flexible duct 306. A strap 310 is placed along the exterior surface of the planar portion 306d and fastening means 312 are utilized to secure D-shaped reinforcing frame 308 and plate 310, with the planar section 306c of flexible ducting 306 sandwiched therebetween. FIGS. 13 through 13b show the manner in which the right-hand end of flexible duct 306 is positioned within the left-hand end of member 304, with clamping plate 310 being positioned within the cutaway portion 304a-1 of planar top 304a. The flexible ducting 306 is preferably force-fitted within the interior of member 304 and is further retained in place when clamping bar 314, which is arranged to engage projection 304c and to rest upon the top surface 304a of member 304 also overlies the top surface 306c of flexible ducting 306 and is clamped in position, as shown for example, in FIG. 13a so that bar 314 rests upon the surface of plate 310 and thereby serves to retain the flexible ducting 306 in position. The left-hand end of flexible ducting 306 is positioned within member 302 in a similar manner, plate 316 being positioned within a cutaway portion of top surface 302a. The invert forming assembly 300 of FIG. 13 is utilized in conjunction with dish-shaped registration members such as, for example, the dish-shaped members 320, 322 and 324, shown in FIG. 14 as being arranged within an associated sidewall opening within manhole base 326. A threaded rod of the type shown as rod 148 in FIG. 6 extends through central openings (not shown) provided within each of the dish-shaped registration members 320, 322 and 324 and threadedly engages tapped openings (not shown) in the outer ends of members 302 and 304, which tapped openings are similar to the tapped opening 142e, for example, shown in FIG. 6. Clamping bars such as, for example, the clamping bar 328 is provided along the exterior surface of the manhole base sidewall 326a and at each sidewall opening. Fastening means, such as, for example, the fastening member 152 shown in FIG. 6 threadedly engages the aforementioned threaded rod 148 and is tightened to firmly urge each dish-shaped registration member 320, 322 and 324 against the gasket 17 (see FIG. 6) within the associated sidewall opening. FIG. 14 shows a manhole base 326 having three sidewall openings and receiving assembly 300 shown in FIG. 13 as well as an additional assembly comprised of member 32 which is substantially identical to the members 302 and 304.
A clamping bar 330 bent at the proper angular orientation is positioned upon planar surfaces 302a and 304a so that it rests against projections 302c and 304c respectively. Clamping members, which have been omitted from FIG. 13 for purposes of simplicity, are utilized to secure clamping bar 330 to projections 302c and 304c. A second clamping bar 334 which is bent at the proper angle is placed upon planar surfaces 304a and 332a of invert forming members 304 and 332 and so that it rests against projections 304c and 332c. Clamping bar 334 is likewise secured to projections 332c and 304c by suitable clamping members of the type shown, for example, in FIG. 11. The assemblies 300 and 332 shown in FIG. 14 assure formation of an invert whose longitudinal axis is in precise alignment with the center of each associated sidewall opening. Horizontal alignment of the members 302, 304 and 332 is assured by the use of the clamping bars 330 and 334, secured in place by the aforementioned clamping members such as, for example, the clamping members C9 and C10 shown in FIG. 11. When the invert forming apparatus is fully assembled, the casting material is poured into the interior of manhole base 326 to a level sufficient to form the substantially T-shaped invert (160a, 160b, 160c - sec FIG. 10) defined by members 302, 304 and 332. Flexible duct 306 assumes a smooth curvature and eliminates the need for removing casting material in the region between the inner ends of members 302 and 304. Thus, when an invert having three branches of the type shown in FIG. 14 is to be formed (note also FIG. 10), casting material need only be removed in the gap region G between the inner end of invert forming 332 and the adjacent sides of members 302 and 304 and flexible ducting 306. The casting material is then allowed to set. In order to expedite the setting operation, a shroud (not shown) may be placed over the base member 326 and steam of a predetermined temperature and pressure may be introduced into the shroud to elevate the temperature of the casting material thereby expediting the setting operation. During casting, operators move and shape the casting material to form sloping surfaces on opposite sides on each of the invert portions to cause any liquid falling upon said sloping surfaces to drain into the invert.
Once the casting material is set, the fasteners 152 (see FIG. 6) are removed to disassemble the invert forming assemblies which are then removed from the manhole base 326, yielding a manhole base whose invert is precisely aligned with the sidewall openings in the base member.
FIG. 15 shows still another preferred embodiment of the present invention in which the invert forming assembly 400 shown in FIG. 15 comprises a main body portion 402 having a substantially semi-cylindrical cross-section. Bell ends 404 and 406 have an enlarged diameter for forming recesses within the manhole base to provide clearance for insertion of a conduit. End surfaces 408 and 410 have a curved configuration to conform to the curved contour of the interior surface of the manhole base side wall.
The top surface 402a of central portion 402 and the top surfaces 404a and 406a of end portions 404 and 406 are substantially flat and coplanar. Handles 412 and 414 extend upwardly from top surfaces 404a and 406a and are secured to the internal support structures as will be more fully described. Each of the handles comprise a substantially U-shaped member having a gripping portion 412a, 414a whose integral free ends 412b-412c and 414c-414d are welded to end plates such as 424. Gripping handles 412 and 414 facilitate the handling and transportation of the invert forming assembly 400.
Each of the curved end surfaces 408, 410 are provided with a tapped opening. Note the tapped opening 410a provided in end surface 410 for threaded engagement with a threaded member forming part of the centering assembly to be more fully described.
Inverted angle arms 416, 418 have their outer ends secured to the upper ends of plates 420, 422 whose lower ends extend into and are anchored within the ends of body portion 402 of the invert forming assembly. Angle arms 416 and 418 act as anti-flotation arms to prevent the invert forming member from being lifted by the concrete poured into the manhole base member during the casting operation, as will be more fully described hereinbelow.
The inner ends of arms 416 and 418 are joined, preferably by welding, to a hinged pin assembly comprised of hinge arms 415a, 415b and hinge pin 415c. Pin 415c moves in the direction of arrow 415d when the invert form 400 is deflected to the 30° deflection angle shown by dotted line 415e, the right-hand portion of invert form occupying the dotted line position P relative the left-hand portion of the invert form. Movement of the right-hand portion of invert form 400 in the direction opposite that shown by arrow 415f causes the pin 415c to move in a direction opposite that shown by arrow 415d.
The "skin" or shell of the invert forming assembly is formed of a flexible plastic material which is preferably urethane, providing a one piece invert form which is designed to create a smooth curved, accurate channel which reduces turbulence and flow contractions that adversely limit flow capacity of the formed invert between the openings in the manhole base. The shell does not form folds or creases along the inside curve C (see FIG. 19c) due to deflection of the invert form. This advantageous characteristic is derived from the fact that the shell is thin enough to prevent such folding or creasing, of either a temporary or permanent nature.
The internal structure of the unitary invert forming assembly is shown best in FIG. 16. Since the opposite ends of the construction are substantially identical in design, only one of said ends has been shown in FIG. 16, for purposes of simplicity.
The internal supporting structure is comprised of a semi-circular shaped end plate 424 which end plate has a curved contour to substantially conform to the contour of its adjacent end surface such as, for example, end surface 410 shown in FIG. 15.
End plate 424 is provided with an opening 424a, as shown in FIG. 16a. A hollow cylindrical member 426 has one open end 426b and one closed end 426a. The open end 426b extends through opening 424a while the closed end 426a projects away from the concave surface 424a of semi-circular plate 424. End plate 424 is also provided with a plurality of openings 424d. The liquid material used to form the shell enters these holes which serve to anchor the end plate 424 within the shell 402 when the shell material sets. An elongated rectangular shaped anchoring plate 422, also shown in FIG. 15, is provided with a rectangular shaped slot 422a extending inwardly from its right-hand edge 422b. Note also FIG. 16a which shows plate 424 and cylindrical member 426 in cross-section. The right-hand side 422a of plate 422 is welded to surface 424a of plate 424 and cylindrical member 426 is inserted within slot 422a and is welded to plates 422 and 424. Hollow cylindrical member 426 has its right-hand end 426a extending beyond the convex surface 424c of plate 424 and has its internal surface threaded as shown at 426c. Anchoring plate 422 is provided with a pair of openings for securing the angle arm 416 thereto as will be more fully described.
An elongated curved plate 428 has its right-hand end 428a positioned against and welded to the concave surface 424b of plate 424, the line of engagement being shown as dotted line 429. End 428a is appropriately curved or rounded to conform to the shape of concave surface 424b.
A pair of elongated rods 430, 432 of rectangular cross-section have their right hand ends 430a, 432a welded to the concave surface 424b of plate 424, the region of engagement being shown by dotted rectangles 431, 433. Two pairs of rectangular plates 434, 436 have their upper ends welded to adjacent sides 430b, 432b of rods 430, 432 and have their lower ends welded to the longitudinal sides 428b, 428c of curved plate 428. Pairs of plates 434 and 436 rigidify the supporting structure comprised of plates 424 and 428 and rods 430 and 432.
The ends 412b, 412c of handle 412 are welded to the concave surface of end plate 424.
An elongated leaf spring member 438 which is designed to flex in a direction shown by double headed arrows 439 and which is substantially inflexible and in fact rigid so as to prevent flexing in the directions shown by double headed arrows 441, which directions are perpendicular to arrows 439, is provided with a cut-away slot 438a at its right-hand end, said slot receiving the projecting portion of cylindrical member 426. The right-hand surface of flexible member 438 is positioned against and is welded to the left-hand surface 422c of anchor plate 422.
The leaf spring also acts as an anti-flotation member and further assures that the invert so formed by invert form 400 has a perfectly linear slope from the higher input opening to the lower input opening to prevent water from collecting along the invert.
A flexible conduit 440 formed of a suitable material such as for example, a coated fabric and having a helical wire 440a extending over its length and imbedded within the fabric cover, has its right-hand end 440b positioned to receive and encircle the leaf spring 438 secured to and projecting from plate 424. As can be seen in FIG. 16b, rods 430 and 432, curved plate 428 and reinforcing strap pairs 434, 436 encircle the right-hand end of flexible duct 440. The right-hand end of flexible duct 440 abuts against the adjacent end 422c of plate 422 (note also FIGS. 16 and 16a).
The right-hand end of flexible duct 440 is maintained in position by a pair of steel straps 442 and 444 which encircle the right-hand end of flexible duct 440 and which are provided with worm screw assemblies 442a, 444a for moving each of the free ends 442b, 444b of each steel strap relative to the opposing ends which are secured to assemblies 442a, 444a, to thereby tighten the steel straps and secure the right-hand end of flexible duct 440 to the supporting structure comprised of members 428, 430, 432, 434 and 436.
Flexible duct 440 has a length sufficient to extend substantially to the opposite end of the invert forming assembly 400 in order to be secured to the structural assembly provided at the opposite end. The structural assembly at the opposite end is substantially identical to the structural assembly of the right-hand end shown in FIG. 16 except that the left-hand end of flexible leaf spring member 438 is not welded to members 420, 424 and 426. Thus the internal structure at the left-hand end of the invert forming assembly 400 is free to be longitudinally displaced from the internal structure at the right-hand end of the invert forming assembly which has a significant advantage as will be understood when performing the casting operation as will be described more fully hereinbelow.
The flexible duct 440 significantly reduces the amount of material needed to form the shell and thus significantly reduces the overall weight of the invert form 400. The shell thickness is limited to prevent the shell from folding or creasing to when forced into a curved contour thus assuring the formation of a smooth invert of uniform cross-section throughout its length.
The internal structural assembly of the invert forming assembly is placed in a mold 450 shown in FIG. 17. Since the left and right-hand ends of the mold are substantially identical, only the right-hand end of the mold has been shown in FIG. 17 for purposes of simplicity.
The mold has a hollow substantially D-shaped central portion 452 and a pair of D-shaped end portions 454 of enlarged diameter such as end portion 454. End wall 456 is provided with opening 456a for receiving a threaded member, as will be more fully described. A pair of supporting brackets 458, 460 are integrally joined to the central portion 452 of the mold adjacent the upper edges 452a, 452b.
The method of molding a unitary invert forming assembly 400 is a follows:
The completed structural assembly having the configuration as shown for example in FIG. 16 is placed within mold 450 so that plate 424, for example, is received within the hollow end portion 462 of mold 450. Plate 424 is accurately positioned by insertion of a threaded member 462, having a threaded portion 462a, into opening 456a and into threaded engagement with tapped opening 426c in cylindrical member 426 (see FIG. 16a). The right-hand end of hollow cylindrical member 422a rests against the concave interior surface 456a of end 456 and is aligned so that its tapped opening 456a is aligned with opening 456a. Threaded member 462 is inserted into opening 456a and threadedly engages tapped opening 426a. When threaded member 462 is appropriately tightened so that the right-hand end of cylindrical member 426 rests against interior surface 456a, plate 424 and hence the entire internal structure is properly positioned within mold 450. It should be understood that the opposite end of the internal structure is inserted and properly positioned within the opposite end of the mold assembly in substantially the same fashion. Flexible duct 440 and leaf spring 438 extend through central portion 452 of mold 450.
After the invert forming assembly internal supporting structure has been inserted into and properly positioned within mold 450, bracket 464 is positioned upon the mold member so that its openings 464a and 464b are aligned with openings 458a and 460a in supporting brackets 458 and 460. Fastening members 466, 468 are used to secure the bracket 464 to supporting brackets 458, 460. Bracket 464 is provided with a pair of slender projections 464c, 464d which are integrally joined to bracket 464 and extend downwardly therefrom. When bracket 464 is properly mounted, the lower free ends 464c-1, 464d-1 of projections 464c and 464d engage the surface of flexible duct 440 in the manner shown best in FIG. 17a.
After the bracket 464 has been mounted in the manner described, liquid urethane is poured into the mold in an amount so that the surface of the liquid urethane is substantially flush with the top edges 452a, 452b of mold 450. Thus, the urethane completely surrounds the internal structure, since the internal structure is designed so as to be spaced inwardly from both the sides and the top open end of the mold so that the urethane, once it is set, substantially completely surrounds the supporting structure, except for the top ends of the anchor brackets 420, 422 and handles 412, 414, to preferably form a shell around the supporting structure, said shell having a thickness in the range from 0.5 to 2.5 inches and preferably in the range from 0.65 to 0.85 inches. In order to reduce the thickness of the shell, the flexible duct may be shaped so that its cross-section defines the letter "D". The D-shaped cross-section 440' is arranged in the mold 450 in the manner shown in FIG. 17.
Projections 464c and 464d engage the top of flexible duct 440 to hold flexible duct 440 in position and prevent the flexible duct from being lifted due to the buoyancy of the flexible duct resulting from the pouring of the liquid urethane into mold 450.
After the urethane has set, bracket 464 is removed. The projections 464c and 464d are sufficiently slender as to facilitate their removal and to have a negligible effect upon the molded urethane. As a practical matter, the urethane substantially fills the void left by the removed projections. Alternatively, liquid urethane may be placed in the voids resulting from removal of the projections 464c, 464d to avoid contamination and/or deterioration of the molded member even after long, continuous use.
The manner in which an invert is formed using the novel invert forming assembly of the present invention will now be described in connection with FIG. 18. The manhole base 480 which has previously been formed and is provided with side wall openings 480a, 480b will now have an invert formed therein by placing the invert forming assembly 400 into the interior of the manhole base. A self-centering cross 482 is inserted into side wall opening 480b, for example. The ends of centering cross 482 engage the side wall opening at 90° intervals. Centering pin 484 extends through an opening at the center of centering cross 482 and has a threaded end 484a which is inserted into opening 408a in bell end 408 of assembly 400. Centering pin 484 is coaxial with the center of the opening 480b. The bell end 408 is placed so that it is flush against the interior surface 480c of manhole base 480. Centering pin 484 is drawn tightly in threaded opening such as, for example, threaded opening 426a shown in FIG. 16a, drawing the invert form snugly against the interior concrete wall.
Assuming an application wherein in the openings 480a and 480b in manhole base 480 are arranged at an angle such that imaginary horizontal lines passing through the central axes of these openings form an angle of less than 180°, the right-hand end of the invert form is deflected as shown by dotted configuration 400' in FIG. 15. A centering cross and centering pin similar to that shown in FIG. 15 are inserted into opening 480a to maintain the invert form in the curved position shown in FIG. 18. The flexibility of the urethane shell allows the invert form to be deflected and locked at the proper angle. The one-piece construction minimizes the costly labor factor during assembly of the invert form into the manhole base and the formation of the invert. The dimensional accuracy of fall and curve of the invert form is assured by use of the novel invert form thus minimizing head loss and frictional resistance. The continuity of the invert diameter, width and finish reduces turbulance and flow contractions while offering maximum flows within the formed invert.
The length of the invert is preferably slightly less than the inner diameter of the manhole base enabling the invert to be slightly stretched when the bell ends 404, 406 of the invert form are snugly urged against the interior wall 480c of manhole base 480. This capability is enhanced by virtue of the fact that the flexible leaf spring member 438 (see FIG. 16) is not rigidly secured, i.e. welded to one of the end plates 424, enabling stretching of the invert form. Thus, the stretching capability of the invert form facilitates both insertion and removal of the invert form from the manhole base.
The angle arm 418 (see FIGS. 15, 16, 16a) is bolted to anchor plate 422 by means of threaded fasteners 419 which pass through openings 418c, 418d in vertical arm portion 418b of angle arm 418 and which threadedly engage one of the tapped openings 422c in anchor plate 422. The horizontal arm portion 418a of angle arm 418 rests upon the top surface 402a of body portion 402. The arcuate-shaped opening 418d allows angle arm 418 to be pivoted either clockwise or counterclockwise about the center axis of opening 418c, as shown by arrows 421a, 421b respectively. This angular orientation enables angle arm 418 to be adjusted to an angle which maintains the adjacent body portion at the desired angle within the manhole base. This is extremely useful in instances where the side wall openings 480a and 480b, for example, (see FIG. 18) are at different heights, necessitating the formation of an invert having a slope to facilitate the smooth flow of liquid downwardly from the higher opening to the lower opening. It should be understood that the angle arm 416 is designed to function in the identical manner.
After the invert form 400 has been placed within a manhole base in the manner described hereinabove. Concrete is poured into the manhole base to the required height and the top of the shelf is finished. The angle arms 416 and 418 serve as anti-flotation members which prevent the otherwise buoyant body portion 402 of the invert form from being lifted by the concrete due to the buoyancy of the invert form relative to the concrete poured into the manhole base. Thus, the light weight of the invert form, which contributes to its buoyancy, enhances the handling and use of the invert form while at the same time the form is prevented from being displaced upwardly by the concrete due to the use of the angle arms 416 and 418.
After the concrete reaches its initial set, invert form 400 may be removed by unscrewing the centering pins and removing them from the invert form and the manhole base. The invert form will contract somewhat to return to its normal length. The invert is easily aid effortlessly removed from the manhole base due to its smooth finish and the smooth continuous curve assumed by the invert form, in the event that the form is deflected as shown, for example, in the arrangement of FIG. 18, for purposes of forming an invert of an angle other than 180°.
In the preferred embodiment, the invert form is designed to deflect approximately 25° in either direction from its normal position. For example, FIG. 19a shows a 180° invert. The 180° invert form 400 is capable of forming any invert between 155° and 205°.
FIG. 19b shows a 135° invert produced by using an invert form 400' which is made using a mold having a 135° angular configuration as shown in FIG. 19b. A 135° invert form designed according to the present invention is capable of forming any invert from 110° to 160°.
FIG. 19c shows a 90° invert 400" which is formed using a 90° invert form. The 90° invert form is produced using an invert mold having the 90° invert shape shown in FIG. 19c. The invert form of FIG. 19c can be utilized to form inverts in the range from 65° to 115°. Thus, through the use of the three invert forms shown in FIGS. 19a through 19c, it is possible to produce every desired invert, and which inverts so formed produce a smooth, accurate channel which reduces turbulence and flow contractions that have an adverse effect upon the flow capacity.
The flexibility of the urethane shell enables the invert form to be deflected and locked to the proper angle within the manhole base by the centering assembly members 482, 484 (see FIG. 15), said angle being adjustable in both the horizontal and vertical plane. The adjustable center support ribs, i.e. angle arms, prevent flotation of the invert form during pouring operations.
FIG. 19d shows another invert form which is utilized to form an invert within a manhole base having three openings 480a, 480b and 480d. It should be understood that each of the individual arm portions 402b, 402c, 402d may be flexed or deflected in the horizontal direction as well as the vertical direction in the same manner as the inverts shown in FIGS. 19a through 19c.
It should further be understood that all of the invert forms of FIGS. 19a through 19d have an internal construction which is substantially similar. In the embodiment of FIG. 19d, two flexible leaf spring members 438 and 438' may be employed to provide the desired flexibility. The ends 438a and 438a' of flexible leaf springs 438 and 438' may be fixed to the associated end plates 424 while their opposite ends 438b nd 438b' may be secured only by the steel clamps 442 and 444 shown, for example, in FIG. 16. To produce the embodiment of FIG. 19c, one continuous section of flexible duct 440 may be provided, for example, between openings 480a and 480d. An opening is provided at a point intermediate the ends of the flexible duct and a section of flexible duct extending through form portion 402c may be placed within this arm so that its first end is adjacent to the end 438b' of leaf spring 438 and so that its opposite end extends into the aforementioned opening formed in the continuous flexible duct section provided within the invert form portions 402b and 402d. Other than these modifications, the remaining internal construction of the invert form shown in FIG. 19d is substantially identical in design and operation to the internal construction of the invert forms shown in FIGS. 19a through 19c. Each of the arms of the Y-shaped invert form of FIG. 19d have the same flexibility and ability to be deflected as is obtained from the invert forms of FIGS. 19a to 19c.
The invert form 400 of FIG. 15 may be mounted on member 53 (see FIG. 12c) in place of the invert form shown in FIG. 12c, with one end of the invert form 400 secured to member 52 and the opposite end being flexible to assume a curved contour, when needed.
A latitude of modification, change and substitution is intended in the foregoing disclosure, and in some instances, some features of the invention will be employed without a corresponding use of other features. Accordingly, it is appropriate that the appended claims be construed broadly and in a manner consistent with the spirit and scope of the invention herein. | Apparatus for forming inverts in a manhole base comprising at least one adjustably positionable channel-forming member for forming an invert which communicates between associated sidewall openings of a manhole base. Flexible members join the ends of the invert form. The adjustability of the channel-forming assembly extends over a range of angles which are both greater than and less than 180 degrees. | 4 |
CLAIM TO PRIORITY
[0001] This application claims the benefit of U.S. Provisional Patent Application No. 61/126,360 filed May 2, 2008, the contents of which are hereby incorporated into this application.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to a dispenser fixture for aromatic materials. More particularly, the present invention relates to a dispenser chamber having a tray for presenting a supply of aromatic materials to a flow of air passing from apertures positioned near or in the end wall of a fixture for dispersing aromatic vapors in a manner that a carrier arm supporting the dispenser orientates a motor driven fan to discharge a stream of air enriched with aromatic vapors in a generally horizontal direction.
[0004] 2. Description of the Prior Art
[0005] A dispenser for volatile fluid is disclosed in U.S. Pat. Nos. 5,533,705; 5,816,845; and 6,105,916. These dispensers provide a drive selectively using a large or small motor providing an air stream for generating vapor from a wick, ceramic wafers, or discs containing vaporizable deodorant and a reversible drive mounting mounted back-to-back. U.S. Pat. No. 6,957,779 discloses a framed fluid delivery device that includes a fluid delivery cartridge for the timed release delivery of a fluid. These known deodorant dispensers are commonly used and recognized by the public because of their use for dispersing fragrances in hostile environments such as restrooms where it is desirous to control the nature of the atmosphere.
[0006] A need exists for a deodorant or fragrant dispenser having a robust construction for discharging air streams within a large room such as a restaurant, coffee house and the like in a manner to produce a pleasant environment conducive to the sale of products on the premises.
[0007] A need also exists for providing a deodorant or fragrant dispenser that is designed so that it is not recognized as a traditional prior art dispenser in order to maintain the privacy of the source of the air stream.
SUMMARY OF THE INVENTION
[0008] The present invention has met these needs. The present invention provides a dispenser fixture for dispersion of aromatic vapors and includes an elongated dispenser chamber bounded by end walls, one end wall containing a fan driven by a motor and the other end wall containing fixtures for supplying and controlling electrical current to power the motor for driving the fan. The dispenser chamber contains one or more receptacles, for example rectangular trays, for presenting a supply of aromatic materials to a flow of air passing from apertures that are positioned near or in the end wall containing the fixtures such that a carrier arm supporting the dispenser fixture orientates the motor driven fan to discharge a stream of air enriched with aromatic vapors in a generally horizontal direction and out into the environment.
[0009] The elongated dispenser chamber further includes upstanding side walls joined with a floor wall containing a load bearing surface supporting at least one receptacle containing a replaceable supply of aromatic material and an inboard end wall supporting an electrical supply utility. In the embodiments of the present invention, the dispenser fixture has one or more apertures for admitting a flow of ambient air into the dispensing chamber. The elongated dispenser chamber includes an outboard end wall having an aperture aligned with an air flow path from a blower supported by the outboard end wall and connected by wiring that traverses the elongated dispenser chamber with the electrical supply utility for energizing the blower. The top wall or cover of the dispenser chamber is mounted by a hinge for pivotally fastening the top wall to one of the upstanding side walls in order to facilitate relative movement from an open position to a closed position. The top wall or cover overlies the upstanding side walls, the inboard end wall, and the outboard end wall.
[0010] The closed position of the dispenser chamber defines a condition in which ambient air supplied by the one or more apertures of the dispenser fixture is enriched with aromatic vapors in the dispenser chamber and is driven by the blower as an ambient exhaust. The open position of the dispenser chamber defines a condition in which the aromatic material supported in the receptacle or receptacles is accessible for replacement in the elongated dispenser chamber. A carrier arm has a mounting flange on a terminal end of the dispenser chamber and projects outwardly from a base adapted for attachment to a support. The mounting flange through suitable fasteners is attached to the dispenser fixture, for example the floor wall, to orientate the floor wall in a substantially horizontal direction and thus the dispenser fixture in a horizontal orientation. Additional fasteners secure the top wall or cover of the dispenser chamber to one of the upstanding side walls, to the inboard end wall and to the outboard end wall of the dispenser chamber.
[0011] It is therefore an object of the present invention to provide a dispenser fixture having a robust construction for discharging air streams within a large room such as a restaurant or a coffee house in a manner to produce a pleasant environment conducive to the sale of products on the premises.
[0012] It is a further object of the present invention to provide a dispenser fixture designed such that it is camouflaged so that it is not recognized as a traditional prior art dispenser and therefore the source of the fragrant air stream is not recognized.
[0013] These and other objects and advantages of the present invention will be better appreciated and understood when the following description is read in light of the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] FIG. 1 is a partial isometric schematic view of a retail establishment selling products and includes a dispenser fixture for the dispersion of aromatic vapors according to the present invention.
[0015] FIG. 2 is a frontal right side isometric view of a first embodiment of a dispenser fixture of the present invention.
[0016] FIG. 3 is a right side elevation view of the dispenser fixture of FIG. 2 .
[0017] FIG. 4 is a left side elevation view of the dispenser fixture of FIG. 2 .
[0018] FIG. 5 is a rear elevation view of the dispenser fixture of FIG. 2 .
[0019] FIG. 6 is an isometric view of the dispenser fixture of FIG. 2 with the top wall or cover pivotally displaced from a closed position.
[0020] FIG. 7 is a view similar to FIG. 6 with the dispenser fixture orientated in a 180 degree position.
[0021] FIG. 8 is a side elevation view of a second embodiment of a dispenser fixture of the present invention.
[0022] FIG. 9 is a frontal right side isometric view of the dispenser fixture of FIG. 8 .
[0023] FIG. 10 is a bottom view of the dispenser fixture of FIG. 8 .
[0024] FIG. 11 is an isometric view of the dispenser fixture of FIG. 8 with the top wall or cover pivotally displaced from a closed position.
DETAILED DESCRIPTION OF THE INVENTION
[0025] FIG. 1 illustrates a side wall 10 and an end wall 12 of a retail establishment or facility F engaged in the sale of a commodity or product, such as coffee, at a counter 14 supported by a floor 16 . A base 18 is mounted to the sidewall 10 and is adapted to be supported by side wall 10 . A carrier arm 22 has a terminal end 22 a which is mounted to base 18 , which in turn is mounted to side wall 10 , through suitable fasteners known to those skilled in the art. Carrier arm 22 further includes terminal end 22 b attached to a mounting flange 20 which in turn is structured to support and be fastened through suitable fasteners to a dispenser fixture 24 , 24 A outwardly from side wall 10 . Dispenser fixture 24 , 24 A is structured to disperse aromatic vapors into the facility and is orientated horizontally within the facility F via carrier arm 22 .
[0026] The structure of dispenser fixture 24 , 24 A and its location within the facility F is such that a high velocity air stream emitted by the facility enters one end of the dispenser fixture 24 , 24 A, is orientated in a substantially horizontal orientation within dispenser fixture 24 , 24 A, and exits the other end of dispenser fixture 24 , 24 A for emission of aromatic vapors out into the facility. Carrier arm 22 may be pivotally mounted to base 18 for pivotal movement with dispenser fixture 24 , 24 A relative to side wall 10 , in which instance, dispenser fixture 24 , 24 A preferably remains in a horizontal positioning relative to carrier arm 22 . Preferably, dispenser fixture 24 , 24 A is an electrical device and includes an electrical supply utility 36 , 114 whose outlet plug 38 , 116 is inserted into an electrical socket 19 in FIG. 1 , more about which is discussed herein below.
[0027] As shown in FIGS. 2-7 , a first embodiment of the present invention involves dispenser fixture 24 having several legs 23 a for supporting dispenser fixture 24 on a surface. Dispenser fixture 24 further includes upstanding side walls 26 and 27 which are joined with a floor wall 28 as best shown in FIG. 5 . As shown particularly in FIG. 7 , floor wall 28 has a load bearing surface 30 for supporting at least one rectangular tray 32 constructed to contain a replaceable supply of aromatic material. As shown best in FIG. 6 , an inboard end wall 34 supports the electrical supply utility 36 in the form of an electrical utility cable with the outlet plug 38 on its free end and a mounting fixture 40 at its entrance into the interior of dispenser fixture 24 .
[0028] Referring particularly to FIG. 6 , suitable wiring 41 is arranged within dispenser fixture 24 for electrically connecting a control switch 42 into a circuit for supplying electrical current by a feed line 44 to a blower 46 , preferably, in the form of an electric motor which is mounted in a fan assembly 47 . With particular reference to FIG. 6 , the fan assembly 47 is mounted to an outboard end wall 48 of the dispenser fixture 24 and has an aperture 50 as shown in FIG. 2 , which is aligned with an air flow path from blower 46 . As best shown in FIG. 2 , aperture 50 and blower 46 are located in the outboard end wall 48 of dispenser fixture 24 .
[0029] Referring again to FIG. 6 , feed line 44 traverses an elongated dispenser chamber 23 . Referring particularly to FIGS. 2 , 3 , 4 , and 5 , dispenser chamber 23 constitutes the volume contained within inboard end wall 34 , outboard end wall 48 , side walls 26 and 27 , floor wall 28 , and a top wall or cover 52 .
[0030] In the first embodiment of FIGS. 2 through 7 and as best shown in FIG. 5 , an end wall extension 34 a of top wall or cover 52 , which is adjacent to the inboard end wall 34 when dispenser fixture 24 is closed, contains spaced-apart parallel openings or apertures 54 for admitting a flow of ambient air from the surrounding environment into the dispenser chamber 23 ( FIGS. 7 and 8 ) of dispenser fixture 24 . Top wall 52 has a generally cross sectional shape in the form of an arc along its length and presents spaced-apart side wall extensions 26 a and 27 a, which are connected by an end extension 34 a as best shown in FIG. 5 . As best shown in FIG. 4 side wall extension 27 a is formed with a cooperating component forming hinges 56 that pivotally fasten top wall 52 to the upstanding side wall 27 in order to facilitate movement of top wall 52 relative to dispenser chamber 23 for an opened and closed position of dispenser fixture 24 . The top wall 52 overlies the upstanding side walls 26 and 27 , the outboard end wall 48 , and the inboard end wall 34 .
[0031] Particularly referring to FIG. 5 , in the closed position of dispenser fixture 24 , there is defined a condition in which ambient air supplied by the apertures 54 of extension 34 a of top wall 52 is enriched with aromatic vapors in the dispenser chamber 23 , which vapors are driven by blower 46 as an ambient exhaust. Referring particularly to FIG. 7 , the opened position of the dispenser fixture 24 , which involves top wall or cover 52 being positioned upward and away from dispenser chamber 23 , defines a condition in which the aromatic material is accessible for replacement in the rectangular tray 32 supported by support surface 30 of the elongated dispenser chamber 23 . Even though FIG. 7 only shows one tray 32 , it is to be appreciated that additional trays 32 may be provided in dispenser chamber 23 and supported by support surface 30 .
[0032] As best shown in FIGS. 3 and 7 , threaded fasteners 58 extend through openings 58 a in the upstanding side wall 26 to engage with threads formed in the side wall extension 26 a (not shown) for securing side wall extension 26 a to upstanding side wall 26 for maintaining dispenser fixture 24 in a closed position.
[0033] To enhance the appearance of dispenser fixture 24 , the outboard end wall 48 includes an upwardly and outwardly extending extension 48 a which joins with an extended part of the top wall 52 to provide an enhanced stream line appearance as best seen in FIGS. 2 , 3 and 4 .
[0034] FIGS. 8-11 illustrate a second embodiment of the present invention involving a dispenser fixture 24 A for dispersion of aromatic vapors according to the present invention. As best shown in FIG. 11 , dispenser fixture 24 A has an elongated dispenser chamber 100 with upstanding side walls 102 and 104 which are joined by a floor wall 106 containing a load bearing surface 108 , which receives and supports one or more rectangular trays 110 . FIG. 11 shows two such trays 110 which are constructed to contain and support a replaceable supply of aromatic material (not shown).
[0035] As best shown in FIG. 8 , an inboard end wall 112 supports an electrical supply utility in the form of an electrical utility cable 114 with an outlet plug 116 on its free end and a mounting fixture 118 at its entrance into the interior of the dispenser fixture 24 A. As best shown in FIG. 11 , suitable wiring within dispenser fixture 24 A is arranged to electrically connect a control switch 120 into a circuit for supplying electrical current by feed lines 122 to a blower 124 , preferably, in the form of an electric motor, which is mounted in a fan assembly 123 . In this embodiment, the upstanding side walls 102 and 104 have a plurality of spaced-apart apertures 126 for allowing a flow of ambient air into the dispenser chamber 100 .
[0036] Still referring to FIG. 11 , blower 124 is mounted to an outboard end wall 128 having an aperture 129 aligned with an air flow path from blower 124 . A top wall or cover 130 is formed with a side wall extension 104 a. Similar to that of dispenser fixture 24 , top wall or cover 130 of dispenser fixture 24 A is mounted by one or more hinges (not shown) to upstanding sidewall 104 . Thee hinges pivotally fasten top wall 130 to upstanding side wall 104 in order to facilitate movement of top wall 130 relative to dispenser chamber 100 from an open position to a closed position for dispenser fixture 24 A. Top wall 130 overlies each of the upstanding side walls 102 and 104 , the inboard end wall 112 , and the outboard end wall 128 when the dispenser fixture 24 A is in a closed position.
[0037] Referring to FIG. 10 , in the closed position of dispenser fixture 24 A, there is defined a condition in which ambient air supplied by apertures 126 located in sidewalls 102 and 104 is enriched with aromatic vapors in the dispenser chamber 100 and which aromatic vapors are driven by blower 124 as an ambient exhaust. In the opened position of dispenser fixture 24 A, a condition exists whereby the aromatic material is accessible for replacement in the elongated dispenser chamber 100 .
[0038] As shown in FIG. 11 , threaded fasteners 131 extend through openings 131 a in the upstanding side wall 102 to engage threads (not shown) formed in the side wall extension 102 a for securing top wall 130 to sidewall 102 for keeping dispenser fixture 24 A closed similar to that of dispenser fixture 24 .
[0039] As best shown in FIG. 9 , the appearance of dispenser fixture 24 A of the embodiment of FIGS. 8-11 is enhanced by the formation of a hood-like extension 160 at the top wall 130 which tapers rearward along side wall extensions 102 a and 104 a to provide an enhanced stream line appearance as best shown in FIG. 9 . Referring to FIG. 11 , top wall 130 extends downwardly along sidewall extensions 102 a and 104 a to form an extension 112 a for inboard end wall 112 . Extension 112 a overhangs inboard end wall 112 when dispenser fixture 24 A is closed as shown in FIG. 8 . It is to be appreciated that when top wall or cover 130 is in the position shown in FIG. 8 , that dispenser fixture 24 A is closed. Legs 136 support dispenser fixture 24 A.
[0040] It is to be further appreciated, that even though dispenser fixtures 24 and 24 A have legs 23 a and 136 , respectively, that in accordance with the present invention, these fixtures may be supported by carrier arm 22 , which may be mounted to a wall 10 of an establishment or facility F as discussed herein above and as shown in FIG. 1 . It is also to be appreciated that dispenser fixtures 24 and 24 A may be made of a relatively hard plastic material or metal and that this material in addition to the structure of the dispenser fixtures 24 and 24 A provide a robust construction.
[0041] While the present invention has been described in connection with the preferred embodiments of the various figures, it is to be understood that other similar embodiments may be used or modifications and additions may be made to the described embodiment for performing the same function of the present invention without deviating there from. Therefore, the present invention should not be limited to any single embodiment, but rather construed in breadth and scope in accordance with the recitation of the appended claims. | A dispenser fixture for dispersing aromatic vapors into a facility includes an elongated dispenser chamber bounded by end walls, one containing a motor driven fan and the other wall containing fixtures for supplying and controlling electrical current for powering the fan motor. The chamber, containing trays supporting a replaceable supply of aromatic material, presents the aromatic material to an air flow passing into apertures positioned near or in the other wall such that a carrier arm supporting the fixture orientates the fan motor to discharge air enriched with aromatic vapors in a horizontal direction into the facility. The fixture includes upstanding side walls joining the end walls, a floor wall joining the side walls and the end walls, and a top wall overlying the side and end walls for enclosing the aromatic materials in the chamber. The dispenser fixture may be made of a hard plastic or metal. | 8 |
FIELD OF THE INVENTION
The present invention relates to a circular knitting machine for knitted fabrics, with two needle beds, a plate and a cylinder, intended for the manufacture of lengths of outerwear, with separation pass, pattern effects and structural effects.
BACKGROUND OF THE INVENTION
The said type of machines are usually given the name "circular machines for sweaters," in which knitting takes place with an assembly of needles, conventionally mounted in rotary needle beds, with dial and cylinder.
The needles are functionally actuated by cam sections which act on the said needles, leading them selectively along alternative paths appropriate for the pattern which is to be knitted, in such a manner that before the action of the cams, each needle has been selected in each section of cams, to follow any of the possible paths in the said section.
In each knitting section, the needles which have been selected to work take up yarn from a yarn guide which, in its turn, receives the yarn from a feed mechanism (such as is known from U.S. Pat. No. 2,006,232), which can be programmed at each revolution of the machine to deliver one or more out of six possible yarns.
In the said circular machines, the fabric is conventionally produced in the form of a continuous tube, with a specific number of spirals of stitches, each fragment of spiral knitted in one revolution of the machine receiving the designation of "pass."
The number of passes which is knitted per revolution of the machine coincides with the number of sections of the machine, when in the revolution in question all the sections are configured as "Jacquard sections," and knit a plain fabric, each pass being knitted by all of the needles of the machine.
However, the number of passes knitted in one revolution decreases when there are inoperative sections and/or when a "Jacquard pattern" of various colors is knitted, and also when each section is configured as a transfer.
In the machines without feeds, the passes join together with no break in continuity, since there exists no beginning or end in the needle beds, because the needles are uniformly distributed over the whole perimeter.
In contrast, in conventional machines with feeds, the passes have a beginning and an end which are physically predetermined, in such a manner that the beginning determines the first needle which receives yarn after the change of yarn delivered by the feed, and the end determines the last needle which knits before a change of yarn is produced, both needles always being the same ones.
Between the last needle and the first needle there is in the needle beds a zone without needles, called a "needle-free zone," which corresponds to the space necessary for the feed to have, conventionally, the means necessary to withdraw, cut, and retain the yarn which has been knitted, and to present, deliver and dispense the yarn which is to be knitted as a continuation.
Fabric is not formed in the said needle-free zone, because there are no needles in it, and the yarn appears in the same in the form of floats, that is, without forming stitches, so that the floats extend between the last needle of the preceding pass and the first of that which follows, which correspond to the last and first physical needles of the needle bed.
Immediately after the needle-free zone, there is what is conventionally termed the "initial zone," which begins with the first needle after the needle-free zone and is formed by a very small number of needles (generally less than twelve) which knit what is called the "initial welt."
In the said initial welt, the needles simultaneously knit two yarns, which are the salient yarn and the recessed yarn, so that the process of fabric formation is given continuity, avoiding the production of a discontinuity when the yarn changes (change of feeds).
Before the needle-free zone, there is what is conventionally termed the "end zone," which is programmed for the needles to knit according to a selection which is suitable for forming the final welt.
The initial zone, needle-free zone and end zone form what is called the "change zone," while the initial and final welts give continuity to the knitted tube, counteracting and eliminating the discontinuity of the needle-free zone, so that to all intents and purposes the fabric is produced physically in the form of a tube, with the consistency and behavior of a homogeneous tube.
The said characteristics permit the actions of stretching, calendering, and rolling up the fabric, which can be effected in the same manner as in a circular machine without feeds. These three actions are exerted by the folding device of the machine, which receives the fabric produced in the form of a tube in the needle beds, and which calenders, flattens, and folds it in two, and which continuously receives it and rolls it up.
In flat bed knitting machines, the fabric is produced in a flat form, and there thus exist a physical beginning and end of the stroke, which permits the production of a fabric with variable width and/or with varied effects.
On the other hand, the effectiveness of the folder in flat bed machines is less, because of the discontinuity of the fabric (which has a beginning and end in each pass), aggravated by the transverse elasticity characteristic of knitted fabrics.
The advantages of variable width and structured fabrics, which the flat bed machines possess with respect to the circular machines, are distinguished by the following:
(a) The variable width consists of knitting with the exact number of needles which are necessary for obtaining the precise fabric width for making the garment which is to be knitted.
This feature eliminates waste in making up, because in each case it is the necessary knitted width which is produced, while in conventional circular machines this arrangement is not possible, due to the physical configuration, because the circular continuity of the needle bed favors and determines the continuity and magnitude of the width of the tube of fabric which is produced.
However, the discontinuity of the change zone in machines with feeds does not permit the said feature, because the first and last needles are always invariably determined.
(b) Structured fabrics are up to now an exclusive feature of flat bed machines, and are obtained by the controllable displacement of the relative position of the needle beds.
In one position, each needle of a needle bed is situated between two needles, which are always the same, of the opposed needle bed, in such a manner that in conventional circular machines the said position is unalterable and never changes, and the stitches of the knitted fabric are always produced in the same order; and in the case of stitch transfers, they are always produced between the same pairs of needles.
In contrast, in flat bed machines, the discontinuity of the process of knitting permits changing the relative position of the needle beds in the dead times which occur at the end of each stroke, and the order in which the stitches are produced can be varied and stitches transferred to different needles in different strokes.
This feature is facilitated in flat bed machines by the obligatory discontinuity of the knitting process at the end of each stroke; however, on the other hand, there is a reduction of the productive capacity, because the dead time always occurs, independently of whether or not the relative position of the needle beds changes in the stroke which develops.
SUMMARY OF THE INVENTION
Given all this, a circular knitting machine is proposed according to the present invention, of the "Sweaters" type, with multi-valued sections capable of producing fabrics of variable width and other effects, by the variation of the relative position of the needle beds.
According to the invention, there are included in the aforementioned machine improvements which affect the systems of feeds and yarn guides, by means of the incorporation of a set of levers which affect the functional behavior of the abovementioned systems, to deliver yarn, cancel feeds, and produce fancy effects.
On this basis, through simple means, a circular knitting machine capable of producing open fabric like that of flat bed machines and tubular fabric of variable width is obtained, thereby exhibiting a great advantage over conventional knitting machines.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a sectional elevation view of the needle bed zone of a circular knitting machine which incorporates the improvements of the invention.
FIG. 2 is a plan view of the general disposition of the elements which are involved in the variable width systems and dial variation in the machines already known.
FIG. 3 is an enlarged detail of the mechanism, shown open, which corresponds to the dial variator.
FIG. 4 is a diagram of a feed in which the portions which constitute the invention are shown detached and drawn with lighter lines, with the canceling lever in the inoperative position.
FIG. 5 is a diagram similar to the preceding one, but with the canceling lever in the operative position.
FIGS. 6-12 show the sequence of delivery of yarn by a feed which has been canceled and which returns to be canceled at the end of the corresponding revolution.
FIGS. 13-17 show the sequence of delivery of yarn from a canceled feed.
DETAILED DESCRIPTION
The invention has as its object a circular knitting machine for knitted fabrics, comprising a needle bed zone (FIG. 1) which comprises an upper ring (1), a cylinder support ring (2), an upper crown (3), a shaft (4) provided with a pinion (5, 6) at each end, a ring (7) termed a "tripod support," and a central shaft (8), with which are associated bearings (9) incorporated in the tripod support (7).
An arm (10) integral with the end of the shaft (8) is disposed in the upper part of this assembly; the said arm (10) faces a drive pin (12) integral with a mechanism (11) which is termed a "variator unit" and whose function is to vary, via interposed elements, the relative position of the needle cylinder (13) with respect to the needle dial (14).
The needle dial (14) is disposed on a support (15) and is provided with the cam sections (17) which in their turn have a support (18), so that the needle cylinder (13) includes cam sections (16) in its turn.
Cams and controls (19) are situated in the upper crown (3) in relation to the feeds, such as is shown by the reference numeral (20) in said FIG. 1.
In the same assembly, the reference numeral (21) indicates a body support ring for the cam sections (16), so that a crown (22) for actuation of the variator is integral with the tripod.
The needle beds of the needle cylinder (13) and of the needle dial (14) are conventionally rotatable, the movement being taken through the respective crowns (2, 3) so that the needle bed of the needle cylinder (13) rests directly on the crown (2), while the needle bed of the needle dial (14) is related to the crown (3) in the following manner:
The variator unit (11) is situated on the said crown (3), and acts through its drive pin (12) on the arm (10) integral in its turn with the support (15) on which the needle dial (14) is disposed.
The crowns (2, 3) receive movement through the pinions (5, 6) of the shaft (4), which is actuated by a motor (not shown); the central shaft (8) rotates on the bearings (9) incorporated into the tripod (7).
The cam sections (16) and (17) of the cylinder and needle dial are static and rest on their respective supports (21) and (18); the feeds (20) are mounted on the tripod (7) and are actuated by the cams and controls (19) situated on the crown (3).
FIG. 2 shows in plan the general disposition of the elements which take part in the systems of variable width and dial variator; a support (23), on which is situated an encoder (24), can be seen, united to the arm (10).
The said encoder (24) generates signals which permit determination of the absolute instantaneous angular velocity of the needle dial (14), corresponding to the sum of the velocity at which the crown (3) rotates, plus or minus the differential velocity at which the variator mechanism (11) displaces the drive arm (10) with respect to the upper crown (3).
Incorporated in its turn on the said upper crown (3) is a box (25) containing the electronic components which control the variator mechanism (11).
In this FIG. 2, the abovementioned upper crown (3) is shown partially cut away to show the openings (26) of the tripod (7) which serve to lodge the feeds (20) so that via said openings (26) the feeds (20) are in operative relation to the cams-and to the controls (19) situated in the lower portion of the crown (3).
The variator mechanism (11), which is shown in detail in FIG. 3, is made up of a support plate (27) on which is a direct current motor (28) having an encoder (36) coupled to its shaft, with which a pulley (29) is also integral, and is connected by a belt (35) to another pulley (34) integral with a spindle (32) which is mounted on one of the centering support bearings (33), while on the said shaft (32) there is mounted a movable nut (31) which slides along guides (30) and which incorporates an integral drive pin (12).
In this assembly, the movable nut (31) slides on the guides (30), driven by the spindle (32) which receives movement from the pulley (34) which in turn is driven by the belt (35) due to the rotation of the pulley (29) integral with the shaft of the motor (28).
Via the encoder (36), the control box (25) determines the position coordinate of the movable nut (31) with respect to its beginning position, and based on this, the main computer of the machine (not shown) sends to the said control box (25) the coordinate which corresponds to the position at which the nut (31) is to be situated and be maintained each time there is a dial variation operation.
On the other hand, the control box (25) furthermore determines, from the signals sent by the encoder (24), the absolute velocity at which the needle dial (14) is displaced, and as a function of the said box (25) controls, in its turn, the movement of the motor (28) in order to position the nut (31) at the selected coordinate in order to vary the position of the needle dial (14).
The action of the variator mechanism (11) on the needle dial (14) takes place in the following manner:
When the motor (28) rotates, the drive pin (12) is displaced, driving the arm (10) which, via the shaft (8) and the support (15), transmits its displacement to the needle dial (14), thereby varying the position of the said needle dial (14) with respect to the upper crown (3), and furthermore with respect to the cylinder support (2) of the needle cylinder (13), because the cylinder support (2) and the needle cylinder (13) are integral, in that the cylinder support (2) and the upper crown (3) always rotate in synchronism.
The operation of varying is carried out according to the following sequence:
#1--At the time for the needle-free zone, all the feeds (20) are canceled and yarn delivery ceases; the said cancellation is maintained during one revolution of the machine plus a fraction of 60°, because the first revolution of the machine is necessary to cut the yarns and put all the needles out of action on the periphery of the machine, while the following 60° is necessary to execute the action of varying.
#2--During the time that the feeds (20) remain canceled, the needles of the dial (14) and of the cylinder (13) are canceled, the cancellation being effected through a Jacquard selection system.
#3--The relative position of the needle cylinder (13) is varied with respect to the needle dial (14) by having the latter displace at a differential velocity with respect to the needle cylinder (13); in that the control box (25), through the information which is sent to it by the encoders (24) and (36), controls the movement in order for this to take place always in 60° of displacement of the needle beds, independently of the machine's velocity or whether it is in an acceleration, braking, or inoperative phase.
The said controller (25) likewise controls the absolute velocity of the needle dial (14) so that it is never negative, in such a manner that in case the position of the said dial (14) has to retrogress with respect to the needle cylinder (13), the relative displacement always occurs at a velocity less than the velocity of rotation of the machine, thus preventing the needles on the cam sections from going in a contrary direction.
#4--The operation of varying being completed, at its step for the needle-free zone, the feeds of the sections which are to form stitches again deliver yarn, and the corresponding needles are selected to receive it.
The operation of cutting yarn takes place automatically each time a yarn is introduced in substitution for a previous yarn, so that it is not possible to cease feeding with the conventional feeds, because to remove one yarn it is necessary to place another, so that it is not possible to cancel the feed.
The said form of operation is valid in machines with conventional feeds, in that it is necessary to insure the continuity of the knitting process, but it is not operative in the proposed machine according to the invention, because the knitting process is discontinuous in the latter, it being necessary to cease feeding yarn and, so, to cancel the feeds, while transferring or while varying the position of the needle dial (14).
Therefore, according to the invention, the feeds (20) are provided in a form which permits them to be selected to act according to two distinct work modes:
OPTION "A": in which the work mode is kept according to the conventional form, that is, the operation of cutting the yarn takes place automatically each time a yarn is introduced to substitute for the previous one.
OPTION "B": in which, without having to introduce a new yarn, the feed (20) can be canceled, cutting the yarn which was being fed.
A modified feed (20) according to the invention can be seen in FIGS. 4 and 5, in which the portions constituting the novelty are shown with lighter lines, and consist of a canceling lever (40) which can be pushed by a rod (41), the said lever (40) resting on a tilt cam (42) which can rotate about a point (43) and on which there is articulated at a point (45) another lever (44) which has a coupling (37) engaged by a spring (48), while the external portion (46) of the said coupling (37) faces a suitable lever (52) of the conventional feed, this lever (44) having at the other end portion a coupling (49) by means of which it is possible to engage on a fixed pin (47).
A feed (20) according to the OPTION "A" is shown in FIG. 4, that is, with the canceling lever (40) in the inoperative position, so that the feed (20) behaves according to the conventional form of actuation, because its operation does not become altered by the presence of new elements which are the object of the invention.
FIG. 5 shows a feed (20) selected according to OPTION "B", related to which in the upper part are shown the canceling control (59) and a scissors cam (53), for variable width, which are integral with the upper crown (3) of the head of the machine, with the canceling control (59) occupying a fixed position with respect to the said crown (3), so that the scissors cam (53) is displaceable and can be situated where suitable for the width of fabric to be produced in each case.
On each revolution of the machine, the canceling control (59), together with the conventional cams and controls, actuates each time one of the feeds (20) to produce sequences of change, or no change, of the yarn and the canceling of the feeds (20).
The canceling control (59) consists of a bistable electromagnet (56), with a core (55) which acts on the push rod (41) in order to situate this in a free position with respect to the canceling lever (40), as in FIG. 4, or in an active position with respect to the said lever (40), as in FIG. 5.
In this latter position, the rod (41) acts against the lever (40), displacing it downward, upon which the cam (42) tilts and causes the lever (44) to advance and become engaged by means of its end coupling (49)) on the fixed pin (47), being maintained in this position by the action of the spring (48).
This displacement of the lever (44) causes the tilting of the lever (52) toward the left, situating it in exactly the same position that corresponds to when there is a yarn change in a conventional feed.
In the said position, the feed (20) becomes potentially canceled, the cancellation being finished at the moment at which the scissors cam (53) is actuated and acts on the lever (57) which causes the cam (58) to tilt, pushing this to the rod (50) which comes into contact with the projection (51) of the movable yarn guide (54), resulting in the cutting and clamping of the yarn in the same form as when there is a yarn change. When this occurs without the delivery of a new yarn, the feed (20) is canceled.
Starting from the position described, when a new operation of yarn delivery occurs, the lever (44) automatically disengages from the pin (47), whereupon the feed (20) changes over to working in the standard manner, until the canceling lever (40) returns to being actuated.
The scissors cam (53) acts on all the feeds (20) on each revolution of the machine, with three possible results as a function of the configuration and selection of each feed (20):
(I) In a feed configured according to OPTION "A", that is, without yarn change, according to FIG. 3, the scissors cam (53) acts on the lever (57), this causes the cam (58) to tilt and the rod (50) descends, without as a result [sic] (51) coming into contact with the yarn guide (54), so that no action takes place as regards cutting and clamping of yarn.
(II) In a feed configured according to OPTION "A", but with a yarn change, the yarn change causes the lever (52) to tilt to the left, in the same way as in FIG. 4, so that the action of the scissors cam (53) on the lever (57) causes the cam (58) to tilt, upon which the rod (50) descends and deviates for the lever (52) to come into contact with the projection (50) of the yarn guide (54), the action of cutting and clamping the yarn therefore taking place.
(III) In a feed configured according to OPTION "B", that is, in a disposition of cancellation, without a yarn change, as in FIG. 4, the scissors cam (53) acts on the lever (57), which causes the cam (58) to tilt, whereupon the rod (50) descends, deviated by the lever (52), to come into contact with the projection (51) of the yarn guide (54), the action of cutting and clamping the yarn which was fed therefore taking place without substituting a new yarn, so that the feed (20) is canceled.
As has already been indicated, the scissors cam (53) is displaceable, able to be situated in the place which is appropriate for cutting the yarn at the level of what in each case is to be the "last needle" corresponding to the fabric width programmed.
According to the result of the actuation of the said scissors cam (53), as previously described, the fabric can be produced in three different forms:
Canceling all the feeds (20) at the end of each revolution, in order to change over to yarn delivery at the beginning of the next respective revolution. In this manner, the fabric which results is open, not tubular, analogously to that produced on a flat bed machine, with variable width.
Without canceling any of the feeds in any revolution. In this manner, the result is a tubular fabric, analogous to what is produced on a conventional feeder machine, with the difference that the dimension of the zone of floats (without stitches) is greater or less, as a function of the situation of the movable scissors cam (53), of variable width.
Combining cancellations of feeds with conventional changes of feeds. The fabric obtained in this manner is tubular and of variable width, partially united by floats.
FIGS. 6-12 represent the sequence of yarn delivery of a feed (20) which was canceled and which returns to be canceled at the end of the corresponding revolution; while FIGS. 13-17 reflect the sequence of the delivery of a yarn after a feed (20) is canceled.
In the said group of diagrams, the reference (60) corresponds to the principal yarn guide, provided with two grooves, the groove (61) for the reception of a single effect yarn (64) coming from the tilting yarn guides (65a), (65b), (65c), (65d) or (65e), and the groove (62) for the conventional reception of any yarn (64) delivered by the feed (20).
In the same diagrams, the reference (63) denotes a conventional cam for delivery of yarn (64), integral with the needle cylinder (13); while reference (66) corresponds to the first needle of the cylinder (13) which receives yarn (64), while (67) is the span of cylinder needles which receive yarn (64), and (68) is the last needle which receives and knits yarn (64).
The reference (69) indicates the needle-free zone between the last needle (68) and the first needle (66) of the needle bed, (70) being a conventional tongue opener; (71) denotes a conventional float guide, (72) a conventional stitch presser, (38) the end of the yarn (64) retained by the feed (20), and (39) a deflecting rod which intervenes over the yarn (64) which one of the tilting yarn guides (65a-e) delivers and conducts to the groove (62).
According to the sequence of FIGS. 6-12, the feed (20) which was canceled, that is, which was delivering no yarn to the needles, is selected for the delivery of the yarn (64) retained by the tilting yarn guide (65e). The cam (63) receives, in a conventional manner, the end (38) of the yarn (64) presented by the tilting yarn guide (65e) and conducted to the groove of the principal yarn guide (60), from where it is received, in a conventional manner, by the first needle (66).
The needles which follow this first one (66) likewise receive the yarn (64) following the sequence (67) of FIG. 11, so that when the last needle (68) receives the yarn (64), the cutter bar (50) descends, actuated by the intermediate levers which connect it to the scissors cam (53), cutting and clamping the yarn (64) in accordance with what was described herein above.
In FIGS. 13-17, the sequence of delivery of a yarn (64) from a canceled feed (20) is repeated; in this case, however, delivery of the yarn (64) is by the tilting yarn guide (65e), but the presence of the deflecting rod (39) leads it to the groove (62) of the principal yarn guide (60).
The yarns (64) delivered to the needles through the grooves (61) or (62) are received by the needles in different positions in the interior of their hooks, to be knitted in a regular manner so that one of the yarns (64) appears on one face of the fabric and the other yarn on the other face. | Circular knitting machine for knitted fabrics, comprising an assembly of needles which are mounted in rotary needle beds provided with cam sections which act on the needles to conduct them selectively according to alternative trajectories, while the yarns to be knitted are delivered in each section in a selective manner by a programmable feed mechanism, which incorporates a complementary assembly which comprises a lever (40) which can be actuated in connection with a tiltable cam (42), which incorporates another associated lever (44) able to be positioned in order to effect the actuation of a rod (50) which actuates cutting and clamping of the yarn being fed, independently of the introduction of a new yarn substituting for the previous one. | 3 |
BACKGROUND OF THE INVENTION
The present invention is directed to a safety surgical scalpel for medical use, having an automatically retractable blade. The present invention can be applied both to disposable scalpels and reusable scalpels.
Many scalpels presently on the market, both of the single-use and the reusable type, are provided with an exposed fixed or interchangeable blade. The exposed blade of such devices exposes the surgeon and those in the operating theater to the risk of serious diseases, such as HIV or vital hepatitis, since the hand-to-hand passing of the bare blade, often contaminated with the blood of the patient, during surgical procedures can cause accidental injury.
To reduce this risk, several blade protection systems have been proposed. For example, WO-90-11725 describes a surgical scalpel which includes a complex mechanism for moving the sheath relative to the blade, to expose the blade in operation. The complexity of this scalpel renders it unsuitable for disposable applications, as well as resulting in a complex manufacturing process. Similarly, EP217638 describes a highly-specialized and complex instrument. However, even in this instrument, the blade must be changed before use, which in itself creates a dangerous situation. PCT/EP93/01458 describes a disposable scalpel provided with a relatively simple mechanical system for retracting the blade. While this scalpel has some advantages, it still has not been completely successful in terms of the ease of its use, so that further improvement has been desired. Retractable blades have also been considered in the context of hand tools such as utility knives (see U.S. Pat. No. 4,028,758, DE-A-3725294 and B-8801175). Such hand tools bear little relationship to the problems faced in designing a surgical scalpel suitable for use in the operating theater.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a surgical scalpel having a blade which is automatically retractable, which can be operated by the hand holding the scalpel to move the blade between a protected and an exposed position, where the blade is automatically retracted when the surgeon's finger is removed.
It is a further object of the present invention to provide such a scalpel in which the finger pressure required to maintain the blade in the exposed position is similar to the finger pressure required to hold the scalpel while in use.
It is a still further object of the present invention to provide a scalpel which fits comfortably within the hand of the surgeon, is capable of precise manipulation and does not obstruct the surgeon's view of the blade while in use.
It is a still further object of the present invention to provide a scalpel with an automatically retractable blade which can be used by right-handed and left-handed surgeons.
It is a still further object of the present invention to provide a scalpel with an automatically retractable blade which can be used by holding the posterior extremity of the scalpel to maintain the blade in an exposed position, so as to permit use of the scalpel in deep surgical fields.
It is a still further object of the present invention to provide a scalpel with an automatically retractable blade which is of simple and inexpensive construction.
BRIEF DESCRIPTION OF THE DRAWINGS
The foregoing and other objects, features and advantages of the present invention will be understood more completely from the following detailed description of the present invention, with reference being had to the accompanying drawings, in which:
FIG. 1 illustrates perspective views of the scalpel of the present invention with the blade in a protected position and in an exposed position;
FIGS. 2A-C illustrate perspective views of the scalpel of the present invention being grasped by a surgeon's hand, with FIG. 2A showing the scalpel with the blade in the protected position, FIG. 2B showing the scalpel with the blade in the exposed position and FIG. 2C showing the scalpel with the blade in the exposed position, but being grasped for use in a deep surgical field;
FIGS. 3, 4 and 5 are sectional views showing the sheath, blade holder and piston of the scalpel of the present invention; and
FIGS. 6, 7 and 8 are sectional views of the scalpel of the present invention, showing the scalpel with the blade in the protected position, an exposed position, and an exposed position for operating on a deep surgical field, respectively.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to FIGS. 1, 3, 4 and 5, the scalpel of the present invention includes three main components, namely sheath 1, blade holder 7 and piston 14.
Referring to these figures and further to FIGS. 6-8, it can be seen that the sheath 1 is a hollow, elongated cylinder having ends 5 and 6. The scalpel blade 8 extends through open end 5 of the sheath in use. The side wall of the sheath is interrupted by lateral windows 2 and 3. These permit access to the interior of the sheath.
Blade support 7 is also in the form of an elongated cylinder. The blade support 7 has a first end 9 which grips the scalpel blade 8. The second end 11 of the blade holder 7 can be hollow to define a vacuum chamber 12 in a manner discussed below. The blade support 7 is provided with a gripping surface 10, which can be defined by two opposed flattened portions on a side of the blade support. It is preferable that the portions 10 are accessible through opening 2, especially when the blade support is in the position where the blade is exposed. It is preferable to provide the portions 10 with gripping aids, which can be in the form of a plurality of ribs extending in the direction perpendicular to the longitudinal direction of the blade support.
The second end 6 of the sheath is closed by cap end 17 on piston 14. Piston 14 is disposed in vacuum chamber 12, with hollow end 11, and thus blade support 7, being allowed to move forward, to expose the blade, and backward, to retract the blade. A groove 15 is provided at the internal end of the piston, for carrying O-ring 16. The O-ring 16 permits sliding movement of the blade support, while maintaining a substantially air-tight seal. That is, the seal is sufficient to permit the development of a vacuum in chamber 12 when the blade is exposed which will retract the blade support upon release of gripping pressure on the blade support. The cap end 17 can be provided with an arm 18 which extends longitudinally in the direction of the first end of the sheath 5, and which is in turn provided with a detent 19 which is able to extend through second opening 3 on the sheath, to maintain the blade support and the blade in the exposed position, for use in deep surgical fields.
The vacuum system is generated by inserting the piston 14 with the O-ring into the chamber 12, and at the same time pushing out the air present in the chamber. This can be accomplished by interrupting the seal between the O-ring and the wall of the chamber 12 with a small diameter synthetic thread (for example, monofilament fishing line) between the O-ring and the wall of chamber 12 when the piston is inserted into the chamber. When the piston has been fully inserted into the chamber 12, the fishing line can be removed to permit the full establishment of the seal.
The use of the present scalpel will now be described, with reference to FIGS. 2A-C and FIGS. 6-8. As can be seen in FIGS. 2A and 6, the blade holder is initially in a position with the blade protected. To use the scalpel, the surgeon uses his finger or thumb to slide the blade holder 7 in the direction of the open end 5 of the sheath. This puts blade 8 in an exposed position. It is preferable for the exposed position for the blade to be defined by the engagement of inwardly-extending lip 4 at the open end 5 of the sheath (see FIG. 3) with end surface 13 of the blade support 7 (see FIG. 4).
Since O-ring 16 forms a substantially air-tight seal with the wall of the chamber 12, the movement of the blade support 7, which causes relative movement between the chamber wall and the fixed piston 14 and greatly expands the effective volume of chamber 12, creates a vacuum in chamber 12. When the surgeon is done with the scalpel and releases the pressure of his finger or thumb, the vacuum created in chamber 12 automatically will return blade support 7 to the original position, i.e. with the blade in the protected position.
To permit use of the scalpel in a deep surgical field, arm 18 is positioned so that detent 19 can extend through the second opening 3 in the side wall of the sheath. Thus, with the blade in the exposed position, pressure on arm 18 urges detent 19 to extend through the opening 3 to provide a stop which engages the end 20 of the blade support, preventing the retraction of the blade from the exposed position. Again, when the surgeon releases the clip (i.e., arm 18), the vacuum in chamber 12 retracts the blade support so that the blade is again in the protected position. It will, of course, be understood that the surgeon will be required to use his other hand to hold the blade in the exposed position through opening 2 while detent 19 is moved into position.
It also is preferred that the blade support 7 be rotatable about its longitudinal axis within the sheath 1. This permits the same scalpel to be used by left-handed or right-handed surgeons. To change between the two, it is necessary only to rotate the blade support through 180° of rotation. Longitudinally-extending ribs 21 can be provided to aid this operation. The provision of the two opposed flattened portions 10 provides the same gripping surface for both right- and left-handed use.
It should be noted that the configuration of lip 4 can be changed to fit various needs also. For example, in one case it may be desirable to configure lip 4 and blade support 7 so that rotation of the blade support is prevented when the blade is in the exposed position. In other cases, for example, when the blade is small or in microsurgery use, the lip can be circular in nature, since in these cases some rotation of the blade is sometimes required during use.
By way of example, the sheath may have a length of about 15 cm and a diameter of about 1 cm. Cylinder 11 may have a length of about 5 cm. The opening 2 may have a length of about 4.5 cm, and may start at a point about 3 cm from the first end 5 of the sheath. The second opening 3 may be located about 3 cm from the end 6 of the sheath.
The present invention is applicable both to disposable scalpels and reusable scalpels (e.g. a diamond-blade scalpel). In the case of the disposable scalpel, the sheath, blade holder and piston can be made of plastic materials. For example, clear 7 polycarbonate can be used for the sheath and polypropylene or polyvinylchloride (PVC) for the blade support and piston, such as a colored polymeric material known by the name MOPLEN. The O-ring can be made of rubber or silicone. In the case of the reusable scalpel, of course the parts of the scalpel usually will be made of stainless steel, except for the O-ring, which again can be made of rubber or silicone.
In addition, while the illustrated embodiment is provided with a fixed piston 14 secured to the second end 6 of the sheath and a hollow-ended blade support 7, it also would be possible to mount cylinder 11 on the end of the sheath and provide the piston 14 on the second end of blade support 7.
Although a detailed description of the present invention has been provided above, those skilled in the art will understand that variations may be made without departing from the principles disclosed herein. Thus, the present invention is not limited to the disclosed embodiments, but rather is defined by the appended claims. | A surgical scalpel includes a blade carried by a blade support, which is slidable within an outer sheath. The blade support is movable from a first position in which the blade is within the sheath to a second position in which the blade is exposed. One end of the blade support has a hollow cylinder, in which a stationary piston is disposed. Movement of the blade support from the first position to the second position creates a vacuum within the hollow cylinder, so that when the surgeon releases his or her grip on the scalpel, the blade support is quickly and automatically retracted to the first position. | 0 |
This is a Continuation, of application Ser. No. 08/672,039 filed on Jun. 26, 1996, U.S. Pat. No. 5,697,038 which is a continuation of application Ser. No. 08/177,318 filed on Jan. 4, 1994, U.S. Pat. No. 5,555,081.
BACKGROUND OF THE INVENTION
The present invention relates to a cleaning device and a developing device incorporated in a facsimile apparatus, printer or similar electrophotographic apparatus. More particularly, the present invention is concerned with a cleaner and toner magazine (abbreviated as CTM hereinafter) having a cleaning unit and a developing unit constructed integrally with each other. The cleaning unit has a cleaning blade for removing a toner left on a photoconductive element after image transfer, and a waste toner tank for collecting it while the developing unit has a fresh toner tank storing a fresh toner.
It is a common practice with an electrophotographic apparatus to form a latent image electrostatically on an image carrier, e.g., photoconductive element, develops the latent image with a developer, i.e., toner to produce a corresponding toner image, and then transfer the toner image to a paper. The paper has the toner image fixed by heat and then driven out of the apparatus as a recording. The toner left on the photoconductive element after the image transfer is scraped off by a cleaning blade and then collected in a waste toner tank. A discharge lamp illuminates the cleaned surface of the photoconductive element to dissipate charges also left on the element. The current trend in the electrophotographic apparatuses art is toward user-oriented maintenance including replenishment of a fresh toner and the collection of a waste toner. For this purpose, the manipulation for maintenance should be simplified. However, a fresh toner tank and the waste toner tank have customarily been constructed separately from each other forcing the user to replace them one by one by a troublesome procedure. Further, in the conventional apparatus, the waste toner tank has to be provided with a sensor responsive to a condition wherein the tank has been filled up with the waste toner.
To eliminate the above problems there has been proposed a system in which the photoconductive element, developing device fresh toner tank, cleaning device and waste toner tank are constructed into a unit; when, for example, the fresh toner tank runs out of toner, the unit is bodily replaced. This, however, increases the cost of the unit as well as the running cost per paper since, for example, the photoconductive element, developing device, cleaning device and waste toner tank which are still usable have to be discarded together with the empty fresh toner tank. Moreover, toxic substances are contained in the unit and apt to invite environmental pollution when the unit is discarded.
Although the manufacture may collect and refill the fresh toner tank even the photoconductive element, developing device, cleaning device and waste toner tank not directly contributing to toner replenishment have to be transported, resulting in an extra transport cost.
In the light of the above there has also been proposed a CTM in which the fresh toner tank and waste toner tank are constructed integrally with each other. The CTM, which is bodily replaceable, simplifies maintenance, eliminates the need for the sensor responsive to the full state of the waste toner tank and solves the environmental pollution problem. In the conventional CTM, the fresh toner tank is fully independent of the developing device and replenishes it with a toner via a long transport path implemented by a motor, screw, guide, agitator, etc.
With an electrophotographic apparatus using such a CTM, the user is expected to perform maintenance including the replenishment of a fresh toner and the collection of a waste toner. It is, therefore, preferable that the manipulation for maintenance be simple, and the frequency of replacement of the CTM be low. To reduce the frequency of replacement, each of the fresh toner tank and waste toner tank should advantageously be provided with a great capacity. However, such bulky tanks are disadvantageous from a space saving standpoint. Further, the fresh toner tank run out of toner simply wastes the space and, in addition, degrades cost performance of the apparatus since it is made up of a number of members for effecting efficient replenishment. Moreover, since the toner is transported over a long transport path, the quality thereof and, therefore, image quality is apt to fall.
On the other hand, an electrophotographic apparatus of the type described is practicable with one of two different charging methods, i.e., a corona charging method and a contact charging method. The corona charging method, which uses a corona charger is predominant today since it is capable of charging the photoconductive element uniformly over a long period of time. By contrast, the contact charging method holds a charger in contact with the photoconductive element. This kind of method is susceptible to the contact condition of the charger with the photoconductive element and the surface condition of the element. With the contact charging method, therefore, it is difficult to charge the photoconductive element uniformly over a long period of time. For example, it is likely that toner particles, paper dust and other impurities deposited on the photoconductive element are transferred to the charger, e.g., charge roller, lowering the charging ability of the charger due to contamination.
However, the contact charger is advantageous over the corona charger in that it produces a minimum of ozone during operation, and in that it is operable with a low voltage. The reduction of ozone, among others, meets the increasing demand for improved office environments. For this reason, the increase in the cost of equipment to be operated in offices is generally accepted. In this situation, the prerequisite is that the contact charger be replaced periodically, and that the deterioration of such a charger due to aging be slowed down.
SUMMARY OF THE INVENTION
It is therefore, an object of the present invention to provide a CTM easy to replace and handle and facilitating maintenance.
It is another object of the present invention to provide a CTM providing a fresh toner tank with a great capacity.
It is another object of the present invention to provide a CTM having a simple construction, increasing the size of a fresh toner tank, reducing the overall size, and saving space.
It is another object of the present invention to provide a CTM which can be mounted to and positioned on an electrophotographic apparatus with ease.
It is another object of the present invention to provide a CTM constructed integrally with a contact charger and slowing down the fall of the ability of the charger.
It is another object of the present invention to provide a CTM promoting stable and sure collection of a remaining toner over a long period of time.
A CTM for replenishing a developing device of an electrophotographic apparatus with a toner of the present invention comprises a waste toner tank for removing a toner left on a photoconductive element of the electrophotographic apparatus after image transfer and collecting the toner, a fresh toner tank constructed integrally with the waste toner tank for replenishing the developing device with a fresh toner, and a connecting mechanism for connecting the waste toner tank and fresh toner tank such that the fresh toner tank is movable to the developing device.
BRIEF DESCRIPTION OF THE DRAWINGS
The above and other objects, features and advantages of the present invention will become more apparent from the following detailed description taken with the accompanying drawings in which:
FIG. 1 is a section of an electrophotographic apparatus implemented with a first embodiment of the CTM in accordance with the present invention;
FIG. 2 is a perspective view of the CTM shown in FIG. 1;
FIG. 3 is a section of the CTM shown in FIG. 1;
FIG. 4 is a section showing an electrophotographic apparatus incorporating a second embodiment of the present invention;
FIG. 5 is a section of a developing device included in the apparatus of FIG. 4;
FIG. 6 is a fragmentary section of the second embodiment;
FIG. 7 is a section demonstrating the operation of a third embodiment of the present invention;
FIG. 8 is a section of an electrophotographic apparatus implemented with the third embodiment;
FIG. 9 is a section of an electrophotographic apparatus incorporating a fourth embodiment of the present invention;
FIG. 10 is a section of an electrophotographic apparatus implemented with a fifth embodiment of the present invention;
FIG. 11 is an exploded perspective view of the embodiment shown in FIG. 10;
FIG. 12 is a perspective view of a connecting member shown in FIG. 11;
FIG. 13 is a plan view showing a seat and a boss included in the connecting member of FIG. 12 and resting on the seat;
FIG. 14 is a section of an electrophotographic apparatus incorporating a sixth embodiment of the present invention;
FIG. 15 is a perspective view of the embodiment shown in FIG. 14;
FIG. 16 is a plan view of the embodiment of FIG. 14 mounted to the electrophotographic apparatus;
FIG. 17 is a section of a cleaning device included in the embodiment of FIG. 14 and disposed in a waste toner tank;
FIG. 18 is a section showing a seventh embodiment of the present invention;
FIG. 19 is a fragmentary section of a conventional CTM;
FIG. 20 is a section of a waste toner tank representative of an eighth embodiment of the present invention;
FIGS. 21A and 21B are perspective views each showing a rotary magnet body included in the eighth embodiment in a particular condition of magnetization;
FIG. 22 is a section of a modification of the eighth embodiment; and
FIG. 23 is a section showing another modification of the eighth embodiment.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Preferred embodiment of the CTM in accordance with the present invention will be described hereinafter.
1st Embodiment
Referring to FIG. 1 of the drawings, an electrophotographic apparatus implemented with a CTM embodying the present invention is shown. As shown, the apparatus has an image carrier in the form of a photoconductive drum 1, a charge roller, or contact charger, 2, and a developing device 3 including a toner reservoir 4, a toner supply roller 5, a developing roller 6, and a blade 7. There are also shown in the figure an image transfer roller 8, a paper separator 9, a CTM 10 embodying the present invention, a discharge lamp 11, a registration roller pair 12, a fixing roller pair 13, and an outlet roller pair 14.
As shown in FIGS. 2 and 3, the CTM 10 has a waste toner tank 21 provided with a cleaning blade 20 which removes a toner remaining on the drum 1 in contact with the drum 1. A fresh toner tank 24 stores a fresh toner and has an opening 23 which is selectively opened or closed by a shutter 22. An agitator 26 is disposed in the fresh toner tank 24. The waste toner tank 21 and fresh toner tank 24 are movably connected to each other by a lever 25. Specifically, a leg 28 extends out from the side wall of the waste toner tank 21 and is engaged with a rotary shaft 27 on which the drum 1 is mounted. One end 25a of the lever 25 is rotatably mounted on the leg 28 while the other end 25b is mounted on a shaft 29 which supports the fresh toner tank 24. As shown in FIG. 2, a lock arm, or retaining member, 30 is rotatably connected to the leg 28 at one end 30a and movable into and out of engagement with the shaft 29 at the other end 30b.
The electrophotographic apparatus has a body or casing 35. As shown in FIG. 2, an elongate slot 36 is formed through the casing 35 in the vertical direction. A liftable member, or returning member, 37 is movable up and down by being guided by the slot 36. The liftable member 37 has an arm 38 extending to a position where it can contact the lower portion of the shaft 29, a guide lug 39 movably received in the slot 36, and a grip 40 extending out to the outside of the casing 35.
The operation of the CTM 10 will be described hereinafter. The image forming procedure implemented by the drum 1, charge roller 2, developing device 3, transfer roller 8 and discharge lamp 11 is conventional and will not be described specifically. In the position indicated by solid lines in FIGS. 1 and 2 and a dash-and-dots line in FIG. 3, the CTM 10 has the waste toner tank 21 and fresh toner tank 24 held in an unmovable condition. The end 30b of the lock arm 30 is held in engagement with the shaft 29 of the fresh toner tank 24. In this condition, the CTM 10 can be removed and replaced easily. The CTM 10 may even be put on the market alone in such an unmovable condition. The CTM 10 is set in a predetermined position within the casing 35 with the leg 28 thereof engaged with the shaft 27 of the drum 1. When the lock arm 30 is rotated, it is released from the shaft 29 of the fresh toner tank 24. As a result, the tank 24 is rotated clockwise, as viewed in FIG. 3, about the end 25a of the lever 25 and brought into the toner reservoir 4 of the developing device 3. Subsequently, the shutter 22 is moved by drive means, not shown, to uncover the opening 23 of the tank 24. Then, the agitator 26 disposed in the tank 24 is rotated to force the fresh toner into the toner reservoir 4.
In the waste toner tank 21, the cleaning blade 20 scrapes off the toner left on the drum 1 after image transfer, as conventional. The toner removed from the drum 1 is collected in the tank 21.
Assume that the fresh toner tank 24 has run out of toner, requiring the user to replace the CTM 10 with a new CTM. Then, the grip 40 protruding from the liftable body 37 to the outside of the casing 35 is lifted along the slot 36 manually. Consequently, the arm 38 of the body 37 is brought into contact with the lower portion of the shaft 29 of the fresh toner tank 24, causing the tank 24 to return to the position where it adjoins the waste toner tank 21. As a result, the lock arm 30 is again engaged with the shaft 29 to prevent the two tanks 21 and 24 from moving. In this condition, the CTM 10 can be bodily removed and replaced with ease.
As stated above, the fresh toner tank 24 replenishes the fresh toner while being received in the toner reservoir 4 of the developing device 3. The tank 24, therefore, plays the role of a conventional toner hopper at the same time. This eliminates the need for a motor, screw and guide otherwise incorporated to convey the toner and, therefore, simplifies construction, reduces size, and saves space. In addition, the CTM 10 is easy to replace since the waste toner tank 21 and fresh toner tank 24 are joined with each other before the replacement.
2nd Embodiment
FIG. 4 shows an electrophotographic apparatus incorporating an alternative embodiment of the present invention. As shown, the apparatus has a photoconductive drum 51 made up of a metallic core and a photoconductive layer formed on the core. A charge roller, or contact charger, 52 uniformly charges the surface of the drum 51 during image forming operation. Optics 53 exposes the surface of the drum 51 imagewise to form a latent image thereon electrostatically. A fresh toner tank 64 and a waste toner tank 62 constitute a CTM as will be described. A developing device 54 develops the toner image formed on the drum 1 by depositing a toner thereon. A transfer roller 55 transfers the resulting toner image from the drum 1 to a paper 56. A fixing roller 57 fixes the toner image on the paper 56 by pressure and heat. An outlet roller 58 drives the paper 56 carrying the toner image thereon out of the apparatus. A pick-up roller 59 picks up the paper 56 and feeds it toward a registration roller 61 via a conveyor roller 60. The registration roller 61 drives the paper 56 toward the transfer roller 55 at a predetermined timing. The developing unit 54 has a hopper 54a on which the fresh toner tank 64 is mounted, a toner supply roller 54b, a developing roller 54c on which the fresh toner from the supply roller 54b is deposited in a layer, and a transfer roller 54d held in contact with the roller 54c. The toner is transferred from the roller 54c to the roller 54d and then to the drum 51.
As shown in the figure, the waste toner tank 62, forming part of the CTM, has thereinside a brush roller 62a for collecting the toner remaining on the drum 51 after image transfer, a flicker 62b held in contact with the brush roller 62a, a cleaning blade 62c held in contact with the drum 51 for scraping off the toner from the drum 51, a magnet roller 62d rotatable while attracting the toner removed from the drum 51, a scraper 62e held in contact with the magnet roller 62d. The reference numeral 63 designates a discharge lamp for dissipating charges left on the surface of the drum 51 after image transfer, thereby restoring it to the initial condition.
As shown in FIG. 5, the fresh toner tank 64 stores a toner T and accommodates an agitator 64a. The agitator 64a is rotatable about a shaft 64e to agitate the toner T and provided with an elastic member 64b on the free end thereof. The agitator 64a and elastic member 64b constitute a conveying mechanism in combination. The elastic member 64a is rotatable to scrape off the toner deposited on the inner periphery 64A of the tank 64. At the same time, this member 64a scoops up the fresh toner T and feeds it into an outlet opening 64c formed in a part of the tank 64. A shutter 64d selectively opens or closes the outlet opening 64c in interlocked relation to the tank 64 which is removable from the apparatus.
As shown in FIG. 6, the waste toner tank 62 and fresh toner tank 64 are linked to each other by a connecting mechanism 68 to constitute a single unit, i.e., CTM 65. As shown, the connecting mechanism 68 has a first arm 66 and a second arm 67. The first arm 66 is mounted on the waste toner tank 62 at one end 66a and bifurcated at the other end 66b. The second arm 67 is mounted on the fresh toner tank 64 at one end 67a and bifurcated at the other end 67b. The two tanks 62 and 64 are joined together by a seal member or similar connecting member, not shown, in the event of packing, such that their contact portions A meet each other.
As shown in FIG. 7, the CTM 65 is mounted to the apparatus body such that the brush roller 62a and cleaning blade 62c, FIG. 4, contact the drum 51 at a position preceding the position where the discharge lamp 63 illuminates the drum 51. At this instant, the bifurcated ends 66b and 67b of the arms 66 and 67, respectively, are engaged with the shaft 51a on which the drum 51 is mounted. After the connecting member has been removed from the CTM 65, the CTM 65 is inserted into the apparatus body. As the fresh toner tank 64 is mounted to the hopper 54a, the shutter 64d is opened while, at the same time, the shaft 64e of the agitator 64a is connected to a drive gear or similar drive source, not shown. During image formation, the agitator 64a is rotated to scoop up the fresh toner T with the free end and elastic member 64b thereof. This part of toner is brought to the outlet opening 64c. The toner T from the opening 64c is deposited on the supply roller 54b and conveyed by the roller 54b to the developing roller 54c. Subsequently, the toner T is transferred from the roller 54c to the transfer roller 54d and then to the drum 51, thereby developing a latent image formed on the drum 51. The resulting toner image is transferred from the drum 51 to a paper.
In a modification of the illustrative embodiment, the two tanks 62 and 64 are not connected by the connecting mechanism 68 and are inserted into the apparatus body in a separated state, as shown in FIG. 4.
As stated above, in the embodiment and modification thereof, the waste toner tank 62 and fresh toner tank 64 of the CTM 65 are separable from each other. Further, since the tank 64 is mounted to the hopper 54a by being rotated, it occupies a minimum of space. Consequently, the tank 64 can be provided with a great volume, and the overall size of the apparatus can be reduced.
3rd Embodiment
Another alternative embodiment of the present invention is shown in FIG. 8. As shown, the CTM 65 is similar to the CTM 65 of FIG. 7 except that the discharge lamp 63 is mounted on the waste toner tank 62. Hence, the discharge lamp 63 is removable from the apparatus body together with the CTM 65.
4th Embodiment
FIG. 9 shows another alternative embodiment of the present invention. As shown, the CTM 65 is similar to the CTM 65 of FIG. 8 except that the charge roller 52 is mounted on the waste toner tank 62. This allows the discharge lamp 65 and charge roller 52 to be removed from the apparatus body together with the waste toner tank 62.
5th Embodiment
Referring to FIG. 10, another alternative embodiment of the present invention will be described. Since this embodiment is essentially similar to the second embodiment of FIGS. 4 and 5, the same constituent parts as the parts of the second embodiment are designated by the same reference numerals. As shown, the CTM, generally 70, is made up of a waste toner tank 71 and a fresh toner tank 72. The waste toner tank 71 is provided with a grip 73 and a bifurcated engaging portion 71 which is engageable with the shaft 51a of the drum 51. To mount the CTM 70 to the apparatus body, the operator holds the grip 73, brings engaging portions 74 into engagement with the shaft 51a, and positions the fresh toner tank 72 on the hopper 54a of the developing unit 54. At the same time as the CTM 70 is mounted to the apparatus body, various constituents disposed in the waste toner tank 71 are each brought to a particular position relative to the drum 51. In the case where the discharge lamp 63 and/or the charge roller 52 are mounted on the CTM 70 as in the previous embodiments, they will also be located in predetermined positions relative to the drum 51.
As shown in FIG. 11 in an exploded view, the CTM 70 has connecting members 75 connecting the waste toner tank 71 and fresh toner tank 72. Each connecting member 75 is implemented as a stepped plate 75a. A relatively long projection or guide 75b is formed on the outer surface of each stepped plate 75a and extends in the direction for mounting the CTM 70 to the apparatus body. As shown in FIGS. 12 and 13, seats 75c for receiving bosses, which swill be described, are formed on the inner surface of each plate 75a.
As shown in FIG. 11, the fresh toner tank 72 is provided with two bosses 72a in an upper portion of each end thereof, and a relatively long projection or guide 72b at substantially the center of each end. The connecting members 75 are affixed to the tank 71 with the seats 75c thereof each supporting the respective boss 72a, thereby completing the CTM 70. As shown in FIG. 13, the fresh toner tank 72 is held integrally with the waste toner tank 71 with some play. The hopper 54a is formed with groove-like guide rails 54e at opposite sides thereof for guiding the guides 72b of the tank 72. A groove-like guide rail 76 is formed in the apparatus body outside of each guide rail 54e in order to guide the respective guide 75b of the connecting member 75.
To mount the CTM 70 to the apparatus body, the guides 75b are slowly inserted into the guide rails 76 while being guided by the latter. At the same time, the guides 72b are inserted into the guide rails 54e. As soon as the engaging portions 74 are brought into engagement with the shaft 51a, the fresh toner tank 72 is positioned in the hopper 54a. The tank 72 has some play, as mentioned above, and can be positioned in the hopper 54a even if the guide rails 54e have some dimensional error.
As stated above, the guides 75b and 72b provided on the CTM 70 and the corresponding guide rails 76 and 54e allow the CTM 70 to be positioned accurately relative to the drum 51 and developing unit 54. In addition, the grip 73 promotes easy handling of the CTM 70.
6th Embodiment
FIG. 14 shows an electrophotographic apparatus implemented with another alternative embodiment of the present invention. As shown, the apparatus has a photoconductive drum 82, a laser unit 84 for scanning the drum 82 with a laser beam, a developing device 86, a transfer roller 88, and a CTM 80. The CTM 80 has a waste toner tank 90 and a fresh toner tank 92 constructed integrally with each other. A cleaning blade 90a and a blade holder 90b are disposed in the waste toner tank 90. When the CTM 80 is mounted to the apparatus body, as shown in the figure, a charge roller 94 contacts the surface of the drum 82. A mechanism, which will be described, causes the charge roller 94 to rotate in association with and at the same linear velocity as the drum 82. When a charge voltage is applied to the roller 94, the roller 94 charges the surface of the drum 82 uniformly to a predetermined polarity. The laser unit 84 scans the charged surface of the drum 82 with a laser beam to form an electrostatic latent image thereon. The developing device 86 develops the latent image with a toner to form a corresponding toner image. As a paper P is transported to an image forming region where the transfer roller 88 is located, the roller 88 transfers the toner image from the drum 82 to the paper P while nipping it in cooperation with the drum 82. After the image transfer, the cleaning blade 90a removes the toner remaining on the drum 82 and collects it in the waste toner tank 90. The fresh toner tank 92 replenishes the developing device 86 with a fresh toner via a duct 86a such that the amount of toner in the device 86 remains constant. When the waste toner tank 90 is filled with the collected toner or when the fresh toner tank 92 runs out of toner, a message for urging the user to replace the CTM 80 is displayed. The user, therefore, can replace the CTM 80 periodically.
FIGS. 15 and 16 show the CTM 80 more specifically. As shown the waste toner tank 90 is formed with an elongate slot 100 in each of opposite ends thereof. The charge roller 94 is mounted on a rotary shaft 94a which is made of a conductive material and rotatably supported by bearings 96. The bearings 96 are each received in the respective slot 100 of the tank 90 together with a spring 98 and constantly biased toward one end of the slot 100 by the spring 98. A drive gear 102 is affixed to one end of the shaft 94a.
As shown in FIG. 16, when the CTM 80 is mounted to the apparatus, a brush 104 contacts the periphery of the shaft 94a. At the same time, the drive gear 102 is brought into mesh with a gear 106 which is connected to a drive motor, not shown. Connected to the brush 104 are a DC power source 108 for generating a DC voltage in association with the drive motor, and a DC/AC converter 110 for converting the DC voltage to an AC charge voltage. In the position shown in the figure, the charge roller 94 is urged against the drum 82 by the springs 98.
During the course of image formation, the charge roller is rotated at the same linear velocity as the drum 82 by the motor via the gears 106 and 102. As a result, the surface of the drum 82 is uniformly charged and prepared for the formation of a latent image using a laser beam.
FIG. 17 shows a device for cleaning the waste toner tank 90 of the illustrative embodiment. As shown, the cleaning device has a stay 112 fixed in place in the tank 90, and a cleaning member 114 fitted on the free end of the stay 112. The cleaning member 114 may be constituted by felt and silicone oil applied thereto. Generally, it is likely that the toner left on the drum 82 after image transfer, paper dust and other impurities are transferred to the charge roller 94, and that the toner scattered around in the apparatus deposits on the charge roller 94. Such deposits on the roller 94, even if a little, prevent the roller 94 from contacting the drum 82 stably. Then, the roller 94 fails to charge the drum 82 uniformly. The cleaning member 114 in rotation slides on the surface of the roller 94 to remove such deposits from the roller 94 and collects them in the tank 90. This is successful in preserving the charging ability of the roller 94 over a long period of time and preventing the interior of the apparatus from being contaminated.
In this embodiment, the charge roller 94 is replaced together with the CTM 80, i.e., the roller 94 whose charging ability lowers due to aging is replaced periodically. Hence, the roller 94 is maintained in a desirable state at all times. It follows that the drum 82 can be uniformly charged by a contact charger which produces a minimum of ozone.
7th Embodiment
FIG. 18 shows another alternative embodiment of the present invention. As shown, the waste toner tank 90 of the CTM 80 is similar to the tank 90 of the sixth embodiment except that a charge brush 116 is substituted for the charge roller 94. The charge brush 116 has a roller portion 118 and a brush portion 120 implanted in the roller portion 118. Assume that the CTM 80 is mounted to the apparatus body, and an image forming operation is effected. Then, a shaft 118a, on which the roller portion 118 is mounted, is driven by a drive motor, not shown, with the result that the roller portion 118 is rotated in the same direction as the drum 82. Further, a charge voltage is applied from the apparatus body to the brush portion 120 via the roller portion 118. In this condition, the outer periphery of the brush portion 120 charges the surface of the drum 82 uniformly while sliding thereon. The tank 90 is provided with a cleaning device, as in the sixth embodiment. The cleaning device is implemented by a thin elastic cleaning sheet 122 which is held in contact with the brush portion 120 at the free end thereof. While the charge brush 116 is in rotation, the cleaning sheet 122 causes the brush portion 120 to elastically deform and vibrate, thereby causing the deposits tofall from the brush portion 120. The deposits so removed from the brush 120 are collected in the tank 90. Again, this is successful in preserving the charging ability of the charge brush 116 for a long time and preventing the interior of the apparatus from being contaminated.
In this embodiment, the charge brush 116 is replaced together with the CTM 80, i.e., the brush 116 whose charging ability lowers due to aging is replaced periodically. Hence, the roller brush 116 is maintained in a desirable state at all times. It follows that the drum 82 can be uniformly charged by a contact charger which produces a minimum of ozone.
8th Embodiment
Another alternative embodiment of the present invention to be described is similar to the embodiment FIG. 14, but it allows the cleaning blade 90a of the waste toner tank 90 to effect more efficient cleaning. As shown in FIG. 19, there has been proposed an arrangement wherein the cleaning blade 90a removes the toner T left on the drum 82 after image transfer with the edge 90'a thereof, while a rotatable brush 124 scrapes it off into the tank 90. This kind of arrangement can collect the toner into the tank 90 more efficiently than the traditional arrangement wherein the blade 90a simply removes the remaining toner from the drum 82. However, the prerequisite for the brush 124 to scrape the toner into the tank 90 is that it be bent to some degree beforehand. In the initial stage of operation, such a bent form of the brush 124 does not matter at all. However, the problem is that the since the tank 90 is usually located in the vicinity of a fixing section, not shown, the brush 124 is apt to deform due to, among others, thermal stresses, resulting in the decrease in toner collecting ability. This embodiment is constructed and arranged to eliminate this problem.
As shown in FIG. 20, the waste toner tank 90 of this embodiment is provided with a holder 126 made up of an arm 126a and a rotatable portion 126b contiguous with the arm 126a. The holder 126 is located in close proximity to the cleaning blade 90a which removes the toner T from the drum 82 in contact with the drum 82. A magnet 128 is affixed to the arm 126a of the holder 126' by a two-sided adhesive tape or hot melt adhesion by way of example. A scraper 130 is located in the range of rotation of the magnet 128 so as to scrape off the toner T from the magnet 128. The holder 126 and magnet 128 constitute a rotatable magnet body 132. In operation, when the magnet body 132 is rotated counterclockwise, as viewed in the figure, about the rotatable portion 126b of the holder 126, the toner T removed by the cleaning blade 90a from the drum 82 is magnetically attracted by and deposited on the magnet 128. As the holder 126 is further rotated, the scraper 130 scrapes off the toner T from the magnet 128 into the tank 90.
FIG. 21A and 21B each shows a particular manner of deposition of the toner T on the magnet 128 which depends on the direction of magnetization. Specifically, FIG. 21A shows a magnet 128a magnetized in the direction perpendicular to the main scanning direction (arrow A) of the drum 82, while FIG. 21B shows a magnet 128b magnetized in the direction parallel to the direction A. The toner T is deposited on the polar portions of the magnets 128a and 128b, depending on the polarity. Hence, the magnet 128b of FIG. 21B can attract the toner T uniformly in the main scanning direction A. The magnet 128a of FIG. 21A cannot attract the toner T in the direction A in the same manner as the magnet 128b unless it is capable of exerting a great magnetic force.
FIGS. 22 and 23 show a modification of the eighth embodiment. As shown, the waste toner tank 90 is also provided with the cleaning blade 90 held in contact with the drum 82 at the edge 90'a thereof for removing the toner T, and the holder 90b. A cylindrical rotatable magnet body 136 is located in close proximity to the blade 90a and provided with a plurality of (four in the modification) magnets 128b each being magnetized as shown in FIG. 21B. The scraper 138 is located in the range of rotation of the magnet body 136, as in the eighth embodiment. It will be seen that the modification has a greater number of magnets and can, therefore, attract a greater amount of toner than the eighth embodiment for a single rotation of the magnet body.
In the eighth embodiment and modification thereof, assume that the amount of toner left on the drum 82 for a unit time is w a (g/sec), that the rotation speed of the magnet body 132 or 136 is n (r.p.m), and that the the amount of toner to deposit on the magnet body 132 or 136 is w b (g). Then, since the ability to remove the remaining toner should exceed the amount of remaining toner to occur, the following relation has to be satisfied: ##EQU1## Therefore, ##EQU2##
The amount w a of remaining toner increases with the increase in the linear velocity of the drum 82. In the light of this, the lower limit of the rotation speed n of the magnet body 132 or 136 may be increased. Specifically, a motor for driving the magnet body 132 or 136 may be rotated at a higher speed, or the gear ratio of the gearing may be changed. This kind of approach, however, would increase the cost or require a different layout. In the illustrative embodiment, the number of magnets on the magnet body 132 or 136 may be increased to increase the amount of toner deposition to twice, three times or even more, thereby lowering the lower limit of the rotation speed n. Further, when the linear velocity of the drum 82 is low, the number of magnets may be reduced. The gist is that the number of magnets of the magnet body 132 or 136 be changed in matching relation to the linear velocity of the drum 82.
Moreover, as shown in FIG. 2, the magnet body 136 blocks an opening 140 formed through the tank 90. When the body 136 is brought to a stop, the magnets 128b are located in the vicinity of a paths N and M along which the toner T flows to the outside. In this configuration, the toner T forming columns on the magnets 128b obstructs the paths N and M so as to prevent the toner T collected in the tank 90 from flowing out.
In summary, it will be seen that the present invention has various unprecedented advantages, as enumerated below.
(1) Since a fresh toner tank included in a CTM is movable to a developing unit, the construction is simplified, the size is reduced, and the space is saved. In addition, the tank can be provided with a great capacity.
(2) When the fresh toner tank is located in the vicinity of a waste toner tank it is held in an unmovable state. In the event of replacement of the CTM, the two tanks can be returned to the position where they adjoin each other. Further, since the two tanks can be replaced in an integral configuration, maintenance is facilitated.
(3) The CTM can be mounted to an electrophotographic apparatus accurately in a predetermined position, simplifying maintenance.
(4) A contact charger, whose ability falls due to aging, can be replaced periodically with the waste toner tank included in the CTM.
(5) A charge roller, or contact charger, remains in contact with the surface of a photoconductive drum stably and uniformly and can, therefore, charge the drum uniformly. This can be done without exerting an extra load on the drum while the drum is in rotation.
(6) A toner left on the drum after image transfer can be collected stably over a long period of time only if the number of magnets carried on a magnetic body is so selected as to set up an adequate toner collecting ability.
Various modifications will become possible for those skilled in the art after receiving the teachings of the present disclosure without departing from the scope thereof. | In a cleaning device and a eveloping device installed in an electrophotographic device, a cleaner and toner magazine (CTM) has a cleaning unit including a cleaning blade for removing a toner left on a photoconductive element after image transfer and a waste toner tank for collecting it, and a developing unit accommodating a fresh toner tank storing a fresh toner. The waste toner tank and fresh toner tank are connected together such that the fresh toner tank is movable relative to the developing device independently of the waste toner tank. | 6 |
FIELD OF THE INVENTION
[0001] The present invention relates to online search services for content published by users in a digital social network.
BACKGROUND TO THE INVENTION
[0002] Conventionally, a number of reference tools have existed to enable people to identify the information they need. Directories, dictionaries and encyclopaedias have come to be replaced by electronic technologies, in particular online search technology.
[0003] Existing search engines index content on the internet and allow users to obtain answers to questions asked in the form of search queries input into a search box. These search engines have adapted to manage the ever larger volumes of information stored on the world wide web (WWW).
[0004] Notwithstanding the growth of online search engines, users still often resort to alternative forms of information management. For example, classified advertisements, both on and offline, and even listings on physical, local notice boards, remain popular ways for individuals to both source and offer goods and services.
[0005] As a result of the large amount of information available in the modern world, both classified advertisement systems and search engines face the problem of delivering information to users that is most relevant to each user's particular needs and circumstances.
[0006] Using existing search engine technology known in the prior art, a typical query entered into a search engine will return more results than a reasonable person could ever sort through or digest. For example, a search for ‘holiday’ entered into two of the four most popular existing search engines returned between 146 million and 377 million results. A query for ‘used car’ returns between 52 million and 74 million results.
[0007] Of these, typically only the first 10 entries generated will be displayed on the first page of results, with just 4 or as few as 2 of these results visible ‘above the fold’ (that is, in the viewable area available to the user) on the most commonly used PC screen.
[0008] Search engines are therefore required to order the results requested in such a manner as to ensure that the most useful or desired results appear first. However, regardless of what algorithm or complex weighting system is adopted, the search engine will return the same results regardless of the individual user's needs.
[0009] Similarly, classified advertisement systems may offer simple search facilities, in addition to ordering results by relevant characteristics such as price, to allow users to navigate the available goods. However, existing classified listings are again not optimised for the individual user and inherently provide the same results regardless of need. As for conventional search engines, currently available classified advertisement systems will return the same results whether the user is a 21 year old male or a 50 year old woman, regardless of their level of knowledge or their circumstances.
[0010] Classified advertisements also suffer from a lack of trust, particularly online. Users are wary about the reliability of those involved in the process. Although online schemes have attempted to address this by incorporating various rating systems to allow users to rate buyers and sellers, these schemes are unsatisfactory in that they have not convinced users that they have sufficient information to be able to judge the reliability of a buyer or seller involved in a given transaction.
[0011] Digital social networks are very popular on the internet, with almost ten percent of all internet time spent on social networking sites such as Facebook®, LinkedIn®, Twitter® and MySpace®. These sites allow users to share content and information within communities of online users and provide a variety of ways for users to interact with each other. Users typically make connections with other users in order to receive content or updates on their ‘friends’ activities. However, existing social networks are primarily communication systems.
[0012] Ineffective scalability has crippled many growing social network based sites and therefore it is important to ensure the system architecture is specifically designed to provide the performance and scalability critical to success.
SUMMARY OF THE INVENTION
[0013] According to a first aspect of the present invention, there is provided a computer implemented method of retrieving published content from a social network of users in which each user has connections to one or more other users, and in which the degree of separation between users within the social network is defined as the number of connections required to connect two given users, the method comprising the steps of:
storing a plurality of content assets published by users in a storage system, each content asset being indexed against one or more users in the network; maintaining a network user map which, for each user, identifies degrees of separation between that user and other users in the social network; receiving an online search request from a first user; searching the stored content assets to identify one or more content assets that match the search request; filtering the matching content assets to identify content assets indexed against users within the first user's network user map; and, generating search results for matching content assets which are ranked in dependence on the degree of separation between the first user and the user or users associated with the one or more matching content assets.
[0020] According to a second aspect of the present invention, there is provided a computer system for retrieving published content from a social network of users in which each user has connections to one or more other users, and in which the degree of separation between users within the social network is defined as the number of connections required to connect two given users, the system comprising:
a database for storing a plurality of content assets published by users, each content asset being indexed against one or more users in the network; a network user map stored in memory which, for each user, identifies degrees of separation between that user and other users in the social network; an application interface for receiving an online search request from a first user; a search engine having a system index for identifying one or more stored content assets that match the search request; and, a processor for filtering the matching content assets to identify content assets indexed against users within the first user's network user map and generate search results ranked in dependence on the degree of separation between the first user and the user or users associated with the one or more matching content assets.
[0026] The present invention provides a content searching service allowing users to search for and retrieve stored content according to their personal relationships with other users who are part of their social network. Unlike conventional methods, the present invention does not provide the same content to every user regardless of context, but rather presents the content according to their relationship with the user(s) associated with (indexed against) that content. People are far more willing to trust content derived from those they know and trust already, and the present invention presents this in accordance with this natural impulse. As a result, the information provided by the present invention is of significantly higher value to users than that provided by prior art arrangements.
[0027] In addition to searching for stored content assets within the storage system accessible by users, the search engine of the system may also include a web index thereby to facilitate searching of the world wide web (WWW) to identify web content that matches the search request.
[0028] Preferably, the content assets are digital content selected from a group including: answers, attachments, categories, classifieds, comments, feedbacks, geocodes, groups, invitations, messages, offers, photo albums, questions, relationships, scrapbook folders, scrapbook items, subscriptions, users and web links. Two or more stored content assets can be linked to create associated content assets which can be retrieved as a single search result.
[0029] Preferably, content assets that are indexed by the search engine are stored within polymorphic tables.
[0030] Each content asset may have associated viewing permissions and therefore preferably the system first determines whether the first user has permission to view a matching content asset before adding the matching content to the search results.
[0031] The connections between users define degrees of separation between them. For example, a first user and a second user who are directly connected are one degree of separation (1-step) apart, while if they are connected via a third party then they are two degrees of separation (2-steps) apart. If two third parties are required to connect the users then they are three degrees of separation (3-steps) apart, and so on. Preferably, the search results indicate the degree of separation. More preferably, the search results identify the one or more users associated with (indexed against) the one or more matching content assets.
[0032] Preferably, the stored network user map is dynamically updated when a new 1-step connection is created between a user and another user in the social network. Preferably the network user map is also dynamically updated when an existing 1-step connection is deleted between a user and another user in the social network.
[0033] Preferably, the network user map is derived from a stored network file which has a list of all user connections with just one degree of separation (1-step apart).
[0034] Preferably, the network user map is created by parsing the network file to identify all connected users with n degrees of separation, where n is greater than or equal to two, and preferably n is equal to 3. The network user map stores all connections between users by degrees of separation. It is stored in volatile memory to ensure that the data is current, the system is scaleable and the performance optimal.
[0035] The search results may also be ranked or filtered in dependence on other criteria such as: the date of origin, geographical proximity, or indications of relevance of the content items.
BRIEF DESCRIPTION OF THE DRAWINGS
[0036] A preferred embodiment of the present invention will now be described in detail with reference to the accompanying drawings, in which:
[0037] FIG. 1 shows a schematic overview of a communications system incorporating an embodiment of the present invention;
[0038] FIG. 2 shows a schematic view of a system architecture in accordance with an embodiment of the present invention;
[0039] FIGS. 3 a - 3 d illustrate an exemplary process of creating a network user map in accordance with an embodiment of the present invention;
[0040] FIG. 4 illustrates an exemplary process of updating a network user map in accordance with an embodiment of the present invention;
[0041] FIG. 5 illustrates an exemplary process of saving a content asset to a user's scrapbook; and,
[0042] FIG. 6 illustrates an exemplary sequence of events that occurs when the embodiment is used as classified advertisement service;
DETAILED DESCRIPTION
[0043] The preferred embodiment of the present invention takes the form of a computer system 10 , as shown in FIG. 1 , providing a website 11 incorporating a social network of users 17 . However, the present invention could equally be incorporated into existing social networks of users. Registered 17 and non-registered users 18 can access the website 11 through the internet 16 and using a conventional web browser or mobile browser, however non-registered users 18 will not be offered full functionality until they register.
[0044] The users' web browsers access the system via the application module 12 . Content published by registered users 17 of the system 10 is stored within a database 14 which is indexed by a search engine 15 , enabling efficient and effective access.
[0045] FIG. 2 expands upon the system 10 of FIG. 1 , and schematically illustrates the software implementation of a preferred embodiment of the present invention. The system is implemented on two Linux® based servers, in which one server houses the application module 12 and the database 15 , and the other server houses the search engine 15 and the network user map 13 . Although in this example, the system is implemented using two co-located Linux® based servers, the skilled person would understand that the system could be implemented using a distributed computer system environment in a number of geographical locations using a number of different servers and configurations.
[0046] Users of the preferred embodiment of the present invention choose to form connections with other users which are stored in the network user map 13 . This provides a number of facilities, only some of which relate directly to the present invention. For example, users may be able to organise social events with, or send messages to, those users with which they have established connections.
[0047] The present invention enables users to obtain information from other users with which they have established connections (their ‘1-step’ contacts), users directly connected to their 1-step contacts (their ‘2-step’ contacts), users directly connected to their 2-step contacts (their ‘3-step’ contacts) and so on. The user is therefore able to make a judgement on the value of the retrieved information according to the degree of separation of the source of that information from themselves. Users can dynamically expand or decrease their filter criteria by varying the degrees of separation used when searching. They may also apply other filter criteria such as geographical location.
[0048] Users may establish connections by sending a request to people who may or may not be registered users of the system themselves at the time of the request. Typically, this request will take the form of an email asking the other person to connect.
[0049] This invitation to connect could take various forms: for example, a simple invitation to connect, or an invitation to connect as a means to answer a specific question, or to help with a specified task.
[0050] By connecting to a series of people, each user would build up their own, unique social network of direct (1-step) connections, likely to comprise people they know from various walks of life, including from their work, their geographical neighbourhood, people they know from school or college, or from a social, sport or special interest club.
[0051] Given each of their own 1-step connections would also invite or be invited to connect with their own 1-step contacts, the original user would gradually build a wider social network of 1, 2, 3 step contacts and so on. Assuming each user connects with 75 users, they would build a social network of 5,625 2-step contacts, 421,000 3-step, 31 million 4-step, and 2.3 billion 5-step connections.
[0052] The user has various options to exploit this network of direct and indirect contacts. For example, a user may ask questions of their direct and indirect network of connections. Such functionality allows users to interact with people they know and with whom they share a sufficient degree of mutual trust for them to be willing and able to ask and answer questions, mimicking real life situations and behaviours.
[0053] The application module 12 of the website 11 incorporates messaging and organisational tools to enable users to set up and manage a group. An example would be a sports club wishing to share information and content between the members of the club. The site stores the ‘network’ of relationships, along with the content entered by each member of that group—in this case, all members of the sports club. A user of the system can be an individual or a representative of a group of individuals.
[0054] At the time of publishing content to the site, the user is offered the choice to make the content ‘private’, which restricts the visibility of that content to the chosen group of individuals, or to leave the content ‘public’ and available for all.
[0055] All of the content published by members of that sports club that is not marked as private is made available to all users of the site (unless the group itself is private).
[0056] In this application, published content shall be referred to as individual ‘content assets’ to aid understanding. The content assets can be associated to multiple individuals or groups within the social network in a variety of ways. Users can be associated with the content assets by interacting with it, such as commenting, saving to a scrapbook (described in detail below), making an offer in response to a classified advert or sharing content assets with a connected user. The system 10 also enables users to control their ongoing association with a content asset and have certain controls over how that content asset interacts with other users, for example, visibility, alerts and update subscriptions.
[0057] A content asset may take a variety of forms. A primary content asset is original content created by a user. All users can create primary content assets using the functionality provided, for example, classified advertisements for products and services, questions, photo albums, personal and group user profiles, invitations between users and scrapbook folders. These original content assets are automatically indexed by, and thereby associated with, the user who created them. The user who created the content asset has a variety of controls over their association to the original content asset which determines how others can interact with the content and the original creator of the content.
[0058] The system 10 enables an individual content asset to be associated with other content assets, known as associated content assets. Users can interact with primary content assets created by themselves or other users, thereby creating further content assets that are associated with the primary content assets. For example, messages and resulting message streams, comments associated with other content assets, offers in response to classified adverts and answers to questions. This collection of content assets is subsequently indexed and made available to other users as a single content asset along with the identity of the creator of the primary content asset and the identities of the creators of the associated content assets.
[0059] In addition, the content asset may be a scrapbook item. Any content asset can be saved by any user into their own or their groups' scrapbooks and optionally within scrapbook folders that the user can create. By saving a content asset the user creates a new asset that refers to the content asset being saved. In addition, users can save websites into their scrapbooks that they find by searching the separate web index. Scrapbook items are effectively associated content assets in functional terms. The system indexes all the scrapbook items, scrapbooks and folders that are stored on the server, thereby allowing users to search the collective scrapbooks and folders of all users.
[0060] Content assets can also include references to and copies of external documents, including PDFs, images, web URLs and associated thumbnails, audio and video files and a variety of third party documents such as Microsoft Word. These documents are always referenced to a primary or associated asset, such as a classified advert or an answer to a question, a scrapbook asset, photo album or a group profile. Preferably, the search engine 15 can also index the content of external documents.
[0061] Over time, the site accrues a rich variety and depth of content as users register, connect with friends and share information through the site.
[0062] All data and content assets are stored in a database 14 , which is implemented using MySQL®. Content assets that are indexed by the search engine 15 are stored within polymorphic tables 19 . These polymorphic tables 19 contain the data to enable users to interact with content and one another through the functionality provided within the application module 12 . By storing the data in polymorphic tables 19 , content assets of different types can be handled in a common manner by the database 14 and content assets can be associated with other content assets. Each table contains the references and content for a specific class of content. The classes of content can comprise: answers, attachments, categories, classifieds, comments, feedback, geocodes, groups, invitations, messages, offers, photo albums, questions, relationships, scrapbook folders, scrapbook items, subscriptions, users and weblinks.
[0063] In the case of a classified advertisement, for example, the content asset would comprise: its ID number and that of its creator user, the category of subject it belongs to (e.g. sports equipment), the owner type (including individual and group), descriptors (including description, price, expiry details etc.), location, comment and offer status and any attachments, together with visibility permissions and alert targets (one or more users who are targeted to receive the advertisement).
[0064] Once information has been indexed, users may search for it as required. If stored information (such as a question/answer, classified advert or saved website) matches the query, that piece of content is returned to the user who has initiated the search.
[0065] When content assets are presented to a searching user, they are presented once only, with all associated users' information and interactions with the content asset clustered or nested. Typically, the content asset presented to the user includes the title and descriptive information of the returned content. In the case of an external website being returned, the URL and thumbnail graphic of that site would be returned also. Advantageously, information indicating the relationship between the user making the search and the user that is the source of the returned content is also shown. For example, the searching user may be informed that the answer came from someone who is a 2-step contact, and who is a 1-step connection of their sister even though the searching user is not connected to the creator.
[0066] Users adding content to the system may ‘target’ it towards specific individuals or groups of users (for example, their 1-step contacts, or members of a particular group). Moreover, search queries may also be targeted in this way. For example, a question could be targeted to all of their 1-step contacts or a specified sub-set of their 1-step contacts, or a classified advert for a child's bicycle could be targeted to those contacts that a user knows has suitably aged children.
[0067] Answers given to questions are typically available to be included in the results of any subsequent, relevant question asked by another user. Similarly, comments on a classified advertisement (such as asking the frame size of the bicycle, for example) are also made publicly available. However, users may designate content as private if they would prefer information they add not to be available to others and users can send private messages to the seller. Users may also designate that only certain other users (such as their 1-step contacts) may see any particular content they add.
[0068] All user interaction with the system is controlled and enabled by the application module 12 , which in this preferred embodiment is implemented using ‘Ruby on Rails’® and comprises multiple functional tools and applications. These include:
communications functionality such as messaging, email, comments and content asset sharing; content asset creation such as tools to create, publish and maintain classified adverts, questions and photo albums; user relationship management including the ability to send and receive invitations to connect with other users, search and browse user profiles and create groups of users; content asset upload such as photo/audio/video file uploads, the ability to attach and index external documents, the search function to search for websites and save links in the system; and, find, save and share including tools, such as the scrapbook, to save and share any content assets with other users and to apply permissions that control the visibility or identity of content and its creators.
[0074] The provision of tools and functionality within the application module 12 allows information to be captured for later searches. Users may make use of the following features to create individual content assets, amongst others:
web-based messaging; a question and answer facility, allowing a question to be targeted to a given set of users to solicit their opinion, either privately or publicly. The questions and related answers may be stored for other users to access subsequently; a classifieds implementation, allowing users to offer items for sale/trade or to source items or services; scrapbooking—the ability to store and group together links to content, whether they be a local item or an external website, as discussed in more detail below; a web search engine—users can make use of this facility, and then subsequently store the results in their scrapbook or the scrapbook of a group they belong to if they wish; and, attachments—uploaded documents or pictures that can be attached to questions and classifieds or stored in a scrapbook.
[0081] The search engine 15 , a third party application, indexes the polymorphic tables 19 in the database 14 and attached documents periodically (at a certain frequency) to ensure acceptable latency for users. For example, the search engine 15 could index the tables 19 every 30 seconds. Any new data, users or content added to the database 14 would then be immediately indexed. This then enables the user to search the index for content assets, according to any combination of application type (e.g. classifieds), content category (e.g. sports equipment) and keyword or search term, in order to retrieve all of the related content in the database from the full range of available content assets.
[0082] In addition, the search engine 15 may comprise an index of internet websites that allows users to implement a standard web search but then allows them to easily save those websites to their personal scrapbook and to share those saved websites with any connected users. The personal scrapbook is indexed by the search engine along with the other content assets. A scrapbook item is associated with the user who saves it.
[0083] Results from a content asset search are preferably displayed with the associated user's name and their relationship to the user asking the question attached to the content asset, allowing the user to make a trust/value judgement on the returned content asset.
[0084] To quickly and easily indicate to the user the degree of separation between them and another user, a colour coding system is used. In this example, the relationship proximities are represented by red for 1-step, orange for 2-step, green for 3-step and blue for not connected.
[0085] The results returned to the user after a content asset search, are presented in dependence on the relationship between the searching user and those users with whom the content is associated. Indeed, in particular examples, the searching user may filter the results according to the degree of separation (1-step contacts, 2-step contacts, and so on) between themselves and the originator of the content.
[0086] The polymorphic table 19 entries are also parsed to determine all users associated with a matched content asset. The results and users may also be weighted at this time to select the most relevant asset to present when there is more than one relevant asset. For example, if a 1-step user has commented on the same asset as a 2-step user, the system will determine which result to present in the collapsed results list based on a set of weightings including date, relationship proximity, user status and geographical proximity.
[0087] Associated search results are then collapsed according to this weighting, in order to deliver only one result for any one classified advertisement to the searching user. For instance, a users comment on a classified advertisement will be collapsed alongside the original classified title and the users photo and orange badge indicating that they are in the 2-step network appended to it. The results will also reference the original creator of the classified advertisement along with the number of offers and comments that exist.
[0088] In order to filter the results, the search engine 15 retrieves from the network user map 13 all user connections for the searching user, whenever a search occurs.
[0089] The network user map 13 stores all connections between users by degrees of separation. It is stored in volatile memory, in this case Random Access Memory (RAM) to ensure that the data is current, the system is scaleable and the performance optimal. In this example, it is limited to 3-step relationships only.
[0090] FIG. 3 a shows the creation of the network user map for an exemplary user.
[0091] The relationships table of the database 14 permanently stores all the user connection information and comprises a row for each user connection (step 30 and FIG. 3 b ). Upon request by the application module 12 , typically at start-up, a network file is created from the table, translating the rows of the database table into an array per user of their direct, primary or 1-step connections (step 31 and FIG. 3 c ).
[0092] A network user map 13 is derived from the network file, by parsing the network file to identify all users within three (in this example) degrees of separation (step 32 and FIG. 3 d ). The network user map 13 is created by de-duping the shared connections between the two 1-step connections of the first user. Finally, the first user is removed from the resulting map to derive a map of all the users connected to the first user. The software used to create the network user map 13 is implemented using the ‘C’ programming language. The network user map 13 is stored in volatile memory (step 33 ), and is retrieved by the search engine 15 for each search, based on the identity of each searching user. The application module 12 enables a user to find other users in the network and invite them to make a connection with them. When an invitation is sent, a new row is created in the invitations table in the database. When the invitation is accepted, a new row is created in the relationships table in the database 14 . This new connection made between two users, triggers the process shown in FIG. 4 . The application module 12 updates any changes to both users' network connections in the network user map 13 , to ensure both the network user map 13 and the database 14 are correct and up-to-date at all times (steps 40 to 43 ).
[0093] As shown in FIG. 5 and briefly discussed above, any content asset can be saved by a user into their personal or group scrapbook. This is then known as a scrapbook asset or item. The user can also create scrapbook folders to contain collections of scrapbook items into useful themes. A scrapbook item is an asset type with its own table in the database which comprises a title, text descriptor, creator and links to the content asset it ‘contains’. Creators of scrapbook items and folders can set permissions to determine their visibility subject to other users' degree of separation from the creating user. The same ‘collapsing’ functions apply to scrapbook items and scrapbook folders as all other content assets.
[0094] The user first requests to ‘save’ a content asset as a scrapbook item in their scrapbook (steps 50 and 51 ). The user is then given options to define the scrapbook item descriptors and visibility permissions. The application module 12 then creates a new scrapbook item in the scrapbook item table in the database 14 . The application module 12 then provides the user with the option to store the scrapbook item within a scrapbook folder (step 52 ). If the user does not, it is stored in the database 14 (step 56 ). If the user wants to store the scrapbook item in a scrapbook folder they are given the option to create a new scrapbook folder or store in an existing scrapbook folder (step 53 ). The scrapbook item is then associated with an existing folder entry in the scrapbook folder table within the database 14 (step 54 ) or a new scrapbook folder entry is created in the database 14 and the scrapbook item associated with it (step 55 ).
[0095] As with all other content assets, scrapbook items and scrapbook folders are indexed by the search engine and can be searched for, ‘scrapbooked’ or shared between users in dependence on a viewing users network associations.
Example
Classified Advertisements
[0096] This example is described with reference to FIG. 6 . In this sequence, the system is used by a specific user to either a) list a product or service for sale, to swap or give away; or b) to seek a product or service to buy, swap or source for free.
[0097] When the system is used by a user to make a product or service available for sale, to swap or give away to others, the user is prompted to select which group of people they would like to be able to see the specific product or service.
[0098] The default selection is everyone who is registered with the system, including but not limited to those people the user is either directly or indirectly connected with, that is everyone who is either a 1-step, 2-step connection and so on.
[0099] Assuming the user chooses to offer the product or service to everyone registered on the system, the sequence of actions is as follows:
[0100] The system adds the user's listing to the database of products and services available, and indexes it.
[0101] Once indexed, that product or service will be included and presented within the results when it meets the selection criteria of any selections made by other users.
[0102] It will also be presented by default to all users on the home page by recency, subject to viewing permissions.
[0103] The user's specific product or service will be made visible to all users who that user selects for that question to be visible to. Also, all categories of user who the specific user selects to be made aware of their specific product or service listing will be subsequently made aware of it via system and email alerts.
[0104] The specific product or service will be presented in the results when other users use the system's search functionality to search or browse for a product or service that matches the user's specific product or service.
[0105] When the system is used by a user to seek a product or service, the user is prompted to select which group of people they would like to see results from. The default selection is everyone registered with the present invention including but not limited to those people they are directly or indirectly connected with, that is everyone who is either a 1-step, 2-step connection and so on.
[0106] The system matches the user's query against the index of classified content assets already indexed from the universe that the user has selected that best match that individual user's question. Again, the user can filter results by the degrees of connectedness between themselves and the user offering the item.
[0107] Each product or service indexed will have a named creator user.
[0108] All classified content assets are displayed with the named creator's identity attached. The order of presentation (i.e. the ranking) is based on a number of criteria including the degrees of separation between the user and the source of each product or service.
[0109] A key feature of the site is the ability to filter these products or services available by the degrees of separation between the specific user requesting the information and the named source of the specific result.
[0110] If the contact network specific to the individual user changes (i.e. if the user adds or deletes a 1-step contact, or if someone who is a one step connection to them adds to deletes a 1-step contact, and so on) then for any search query that is requested subsequent to that user's contact network being updated, results will be filtered by that user's most up to date contact network. Users can dynamically expand or decrease their filter criteria by varying the degrees of separation used when searching. They may also apply other filter criteria such as geographical location.
Step 1 User A Posting a New Classified Advert
[0111] Upon clicking the link to post a new Classified, User A is presented with a form to complete with a short description, full description, desired price of item, category (to allow browsing of Classifieds by similar objects/services) and an expiry date (after which Comments and Offers will not be accepted). The user can upload a photo to aid description/visualisation or upload a document to provide more detailed information.
[0112] The user then selects which group of people they would like to notify about the new Classifieds listing, choosing from all their 1-step friends, an ad-hoc selection of their 1-step friends, their 1 and 2-step friends combined, or groups they are a member of.
[0113] The final option on the form is to limit the visibility of the Classified to those selected in the notification stage, thus preventing users outside of this selection from seeing the Classified or any of its associated Comments.
[0114] Assuming the user chooses to make the classified advert available to everyone registered on the system, the sequence of actions is as follows:
[0115] The Classified details (descriptions and any attached assets or documents) are stored in the database and indexed by the search engine.
[0116] Notification Messages are sent to the users selected as the ‘target’ for this Classifieds listing. These messages are presented to each user in their ‘Message Inbox’ and via email provided by the system, and the message contains a link to go directly to the particular Classifieds listing.
[0117] The creator user can edit or close the classified at any stage.
Step 2. User B Commenting on the Classified Listing
[0118] Clicking this link displays the Classified listing and any Comments to-date. User B can submit a Comment to the Classified advert from this screen; this Comment is then stored in the database and indexed by the search engine.
[0119] A Notification Message is sent to User A whenever a Comment is posted to their Classified. The commenting User B is automatically subscribed to subsequent alerts. User B can opt out at any time.
Step 3. User C Making an Offer for the Classified Item
[0120] If User C is interested in making an offer for the item being advertised they can enter an amount, or details of another item they are offering to exchange, into a form. Additionally, they can accompany the offer with a private message containing conditions/caveats of offer etc.
[0121] The Offer details are then stored in the database and a Notification Message is sent to User A informing them of the Offer. User A and C can then agree collection/despatch details between themselves. The offer price without the user's identity is then displayed within the classified detail page.
[0000] Step 4. User D Saving the Classified Advert to their Scrapbook
[0122] The latest Classifieds submitted to the site are presented for the user to browse. They are also given the option to browse by Category.
[0123] In each of these cases, the results are obtained by performing a search for the latest Classified listings. The search engine checks to see that User D is allowed to see each document before including it in the result set, and it uses the NetworkMap to calculate the degree of separation between the Classified owner and User D so that a suitable graphic can be presented back to the user to signify the degree of separation.
[0124] Upon clicking one of the links, User D is presented with the Classified details in full, along with any Comments and offers to-date. Links are presented here to allow User D to reply with her own Comment or Offer, Save to her Scrapbook, or Share with a Friend.
[0125] Clicking “Save to Scrapbook” opens a form to allow the user to add a category and description, and the system then stores a link to the content in the user's account. This content is indexed by the search engine, and becomes another content asset that can be searched for and presented to other users.
[0126] “Share with a Friend” sends a link to the content in a Message to a selected friend or friends, allowing users to share discoveries and information.
[0127] Step 5. User E Searching for Information and being Presented with Results that they Subsequently Filter by their Network
[0128] When User E enters a search term into the ‘Search Classifieds’ input field on the site, the search engine first finds all matching Classifieds listings based on keyword-matching.
[0129] If any of the results found are marked as “Private” it then checks to see if User E is within the target permission network selected at the time the Classified was listed and discards the result if not.
[0130] For each of the results, the search engine then calculates the degree of separation between the Classified creator and User E, returning this to the Application along with the result summary.
[0131] If User E chooses to filter the results by their 1, 2 or 3-step network, the previous lookup is also used to control which results are included or discarded from the result set.
[0132] Two further filtering options are available to User E:
1) Geographical filtering—using geo-location technology to pinpoint User E with a location they specify, and comparing this to the location associated with the Classified advert.
In this way, a filter can be applied to present only those Classifieds posted by users within a given radius of a point.
2) Groups—filtering the displayed Classifieds to show those posted by the members of a Group that User E is also a member of. Classifieds can also be posted “on behalf of” a Group by the Administrator of that Group, allowing a cricket club to sell their old practice nets, for example.
[0136] If User B is in User E′s 1-step network but User A is not, User E will then be presented with a collapsed comment asset detailing the comment made by User B. In this way, User E is able to view the comment and the original classified advert (if the permissions allow) even though User A, the original creator of the content asset, is not in User E′s 1, 2, or 3-step network.
[0137] It is important to note that while the present invention has been described in a context of a fully functioning data processing system, those of ordinary skill in the art will appreciate that the processes of the present invention are capable of being distributed in the form of a computer readable medium of instructions and a variety of forms and that the present invention applies equally regardless of a particular type of signal bearing media actually used to carry out distribution. Examples of computer readable media include recordable-type media such as floppy disks, a hard disk drive, RAM and CD-ROMs as well as transmission-type media such as digital and analogue communications links. The illustrated separation of components and functions into distinct units may reflect an actual physical grouping and allocation of such software and/or hardware, or can correspond to a conceptual allocation of different tasks performed by a single software program and/or hardware unit. | In the present invention, there is provided a computer system ( 10 ) for retrieving published content from a social network of users in which each user has connections to one or more other users, and in which the degree of separation between users within the social network is defined as the number of connections required to connect two given users. The system ( 10 ) comprises a database ( 14 ) for storing a plurality of content assets published by users, each content asset being indexed against one or more users in the network, a network user map ( 13 ) stored in memory which, for each user, identifies degrees of separation between that user and other users in the social network, an application interface ( 12 ) for receiving an online search request from a first user, a search engine ( 15 ) having a system index for identifying one or more stored content assets that match the search request; and a processor for filtering the matching content assets to identify content assets indexed against users within the first user's network user map and generate search results ranked in dependence on the degree of separation between the first user and the user or users associated with the one or more matching content assets.
The present invention provides a content searching service allowing users to search for and retrieve stored content according to their personal relationships with other users who are part of their social network. Unlike conventional methods, the present invention does not provide the same content to every user regardless of context, but rather presents the content according to their relationship with the user(s) associated with (indexed against) that content. | 6 |
BACKGROUND OF THE INVENTION
The present invention relates to a process to cool melt-extruded filaments made of thread-forming polymers, as well as a device to carry out the process.
Filament yarns and extruded fibers made of thread-forming polymers such as polyester, polyamide or polyolefine are conventionally produced in the melt-extrusion process. In this process, a molten mass of polymer is fed to a viscose pump which conveys the molten mass through the extrusion nozzles in the so-called extrusion block. The molten mass emerging from the nozzles in the form of liquid filaments congeal as they emerge in a cooling shaft. Subsequently simultaneous preparation, i.e. humidification of the equipment with an antistatic preparation and similar products also takes place before the filaments are conveyed to a further process. Cooling of the liquid filaments emerging from the extrusion nozzle has here a great influence on the titer uniformity (Ust value) and on the technological textile properties of the fiber and yarn in the end products. In some applications, e.g. with high individual titers, the yarn strength drops off as the production speed is increased (g/min/hole) (U.S. Pat. No. 4,973,236). The reason for this, among other things, is insufficient cooling of the molten stream coming out of the nozzle opening.
As a rule air, but sometimes also water is used as the cooling medium.
Air cooling has the advantage that the air exerts little friction on the emerging filaments so that undesirable drafting is avoided. However, the insufficient cooling action of the air is a disadvantage, so that a long cooling distance is necessary. However, a long cooling distance means slow cooling. Slow cooling favors the formation of crystallite in the yarn, and this causes problems in subsequent drafting. A high through-put capacity (g/min/opening) or thicker individual filaments require an especially long cooling distance, since the cooling speed is low. As mentioned above, this involves the danger of crystal formation in particular with this spun material.
Cooling is usually effected by blowing across the filaments. The air stream must be relatively free of turbulence here, and must move at a uniform speed over the funnel width so that every filament may be subjected to the same amount of cooling at the same time and location. Perforated metal sheets or sieve webs in combination with honeycombs are used in order to produce the required flow conditions. It is also possible to provide a speed profile over the height of the cooling funnel. In spite of these measures, which are expensive at this time, even cooling of all individual filaments is not ensured in case of a high number of filaments per surface. With lateral blowing, a temperature gradient is produced from filament to filament, so that the number opening rows provided for in the air stream is limited.
From U.S. Pat. No. 4,425,293 it is also known to use water as the cooling medium. The advantage of water cooling is rapid removal of the heat and therefor avoidance of extrusion crystallization. However a high degree of friction between water and filament is a disadvantage in water cooling. This may lead to undesirable drafting of the filaments. It has already been tried to calculate and design the undesirable drafting during water cooling so that a desired drafting takes place (U.S. Pat. No. 5,268,133 and WO 91/181 133). However such measures have been shown to be complicated and not without problems.
OBJECTS AND SUMMARY OF THE INVENTION
It is a principal object of the present invention to create a process which improves the cooling of the molten extrusion mass emerging from the nozzles and thereby to also make the spinning of stronger filaments at higher speed possible without crystal formation in these filaments which would have a disadvantageous influence on the subsequent drafting or drafting/extruding process. Additional objects and advantages of the invention will be set forth in part in the following description, or may be obvious from the description, or may be learned through practice of the invention.
It has been shown that by using foam, the cooling action is surprisingly increased considerably without producing the great hydrodynamic frictional force of the filaments which is known to take place with water. The formation of a liquid film on the filament surface achieves however the nearly identical cooling effect as water. The process according to the invention also avoids the disadvantage of the lateral blowing.
Further advantages of the invention result from the fact that the construction of extrusion installations can be achieved with very low constructive height because of the drastically reduced cooling distance. This results in considerable savings. Further details of the invention are described through the figures.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 schematically shows an installation for the spinning of melt-extruded filaments made of yarn-forming polymers, whereby the parts of the installation which are not essential to the invention have been omitted;
FIG. 2 shows another embodiment of the foam equipment; and
FIG. 3 is a graphic representation of the cooling process according to the state of the art and according to the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Reference will now be made in detail to the presently preferred embodiments of the invention, one or more examples of which are illustrated in the drawings. Each example is provided by way of explanation of the invention, and not as a limitation of the invention. For example, features illustrated or described as part of one embodiment can be used on another embodiment to yield still a third embodiment. It is intended that the present invention cover such modifications and variations.
Extrusion nozzles 2 from which the filaments F emerge are installed on an extrusion block 1. Before these filaments F leave the nozzles 2 in liquid form and can be conveyed to any further processing step, they must be congealed by cooling so that they can be wound up on bobbins, for example, or be deposited in the form of yarn bundles in cans. For this reason, the run through a so-called cooling path SK (FIG. 3) on which the yarns are conveyed freely, without touching each other or other objects, and where they are cooled down from the usual melting temperature of approximately 300° C. to a limit temperature t G which is around 70° C. Only when this limit temperature t g has been reached or when the temperature has fallen below it, are the filaments F allowed to make contact. In FIG. 3, the temperature t of the spun material is shown at distances in meters (m) in degrees centigrade over the path SK which the spun material must cover until it has been cooled down to a given temperature. This line t g indicates the temperature to which the spun material must be at least cooled before any contact is made (limit temperature). The cooling conditions for a polyester POY monofilaments of titer 22-35 dtex for example, are represented by the curve A. In this case cooling takes place as usually by air with its own temperature corresponding to the room temperature of approximately 20° C. The course of cooling shows that, in this type of cooling and at a production speed of 3600 m/min, the limit temperature of approximately 70° C. is reached only after a cooling path SA of approximately 3.5 m. Only at this distance from the nozzle have the filaments reached sufficient strength through cooling so that they may come into contact with each other or also with yarn guiding elements etc.
If the product speed is increased or a thicker titer is spun, an even longer cooling path SK which may be as long as 5 or even 6 meters is required. The disadvantage of such a long cooling path have been mentioned earlier. Since a first contact of the filaments F may only occur at this distance from the nozzle, this means that the entire installation reaches a great constructive height. Because of these dimensions, the installations becomes more expensive, aside from the fact that the filaments F are also exposed to uncontrolled influences on the cooling path.
The use of water would certainly shorten the cooling path due to good heat transfer. However, great disadvantages occur because of the strong friction between water and filaments. Surprisingly it has now been shown that with foam a similarly strong cooling action can be reached as with water. However, the damaging friction between filament and foam does not occur as with water.
The cooling conditions for foam with different shares in volume of liquid are shown in curves B and C in FIG. 3. From this it can be seen that for a foam with a liquid volume share of 5%, the cooling path is shortened to approximately 1.1 to 1.2 meters under the same conditions as for curve A. With a higher share in volume the cooling path is further shortened because heat transfer also increases considerably as a function of the volume share of liquid in the foam. Thus, curve C for example shows the cooling course for a foam with approximately 10% of liquid volume share. Here the cooling path SK is shortened to the length of path SC which is less than 1 meter long, in order to reach the limit temperature.
In FIG. 3 the overall cooling course is shown, from the emergence from the extrusion nozzles to the preparation for the next treatment process. In air gap S between nozzle plate 2 and foam container 3 a relatively flat course of the temperature drop is noted. With entry into the foam, the cooling curve becomes noticeably steeper than if cooling were to be effected only by air, and thus reaches the limit temperature t g after only a short distance.
It need not be said that this considerable shortening of the cooling path SK not only improves the technological characteristics and production conditions considerably for heaver titer, but that also much smaller dimensions of the spinning installation can be achieved. The heights can easily be reduced to one half to one third, and this leads to considerable savings in the installation of such equipment.
As appears from FIGS. 1 and 2, a foam container 3 or 30 is installed below the extrusion block 1 and the nozzle plate 2, at a distance S. The distance S may be very short, e.g. only 1-2 cm. Its size depends on the filament thickness and on production speed. Since the filaments F emerge in liquid form from the nozzles 3, a certain amount of congealing is necessary before they dip into the foam. This congealing is considerably quicker with thin filaments than with thicker titers, where this distance from the foam may be up to 1.5 m, depending on production speed.
The foam container 3 is supported by a frame 32 and has on additional input opening 31 at its upper end so that the filaments F cannot touch the sides of the foam container 3, while an opening 35 through which the filaments F leave the foam container is provided at its lower end. Due to the widening cross-section of the foam container 3, the speed of flow of the foam is reduced and the formation and separation of the liquid is thus promoted so that the spun material conveyed in the counter-current through the foam is wetted and cooled intensively. Since the filaments F fill out this narrow opening 35 to a great extent and in order to avoid any contacts, the limit temperature t g must have been reached with certainty by this point in time. As can be seen in FIG. 3, this determines also the height of the foam container 3.
At the lower end, close by the output opening 35, a foam producer 5 is installed which has an air feed 51 and a cooling liquid feed 52 and which feeds the foam directly into the lower part of the foam container 3. While the foam rises continuously due to the continuous foam production, the filaments F are conveyed in the counter-current from the top down through the foam container 3 and emerge from the foam container 3 at the output opening 35 to be then conveyed to a further process. The rising foam is controlled by a sensor 4 which regulates the level, in some cases via level regulator 41. The edge of the upper input opening 31 of the foam container 3 is made as an overflow spillway so that the liquid which forms again may flow off over the edge if necessary. The overflowing liquid as well as the liquid produced in the foam container 3, because it forms again and flows downward, is collected in a collecting trough 33 and is fed back to the circulation pump 7 via discharge line 36.
The foam producer 5 is fed continuously by the circulation pump 7 which also products the circulation of the liquid fed back from the foam container 3. Water is brought into the circuit by the dosage pump 72, to the extent that liquid is consumed by foam production and cooling of the filaments F. A second pump 71 feeds preparation oil to the liquid. Both are then pumped by the circulation pump 7 through a mixer 6 and are thus added to the liquid which is fed via line 52 to the foam producer 5. In the foam producer 5, air is added to the liquid through air feed 51 and foam is thus produced which is delivered in the lower part of the foam container 3.
At the beginning of spinning, the foam container 3 is at first empty. The filaments F emerging from the nozzle 2 fall down into the foam container 3 and are introduced into the output opening 35. For this, a shutter 34 is used which makes the lower part of the foam container 3 accessible. After introduction of the filaments F the shutter 34 is closed again and the foam is brought in. The sensor 4 checks the rising foam and regulates via a regulator 41 the motor 42 which drives the water dosage pump 72 for water arrival. Thus, the level in the foam container which is controlled by the sensor 4 also determines the cooling path length SK which the filaments require as they go through the foam.
In the process of filament cooling by foam according to the invention, the foam bath is used simultaneously to apply the preparation solution on the filaments F. The installation according to the invention thus also contains the necessary preparation device. Below the foam container 3, the emerging filaments are scanned by two electrodes 8. The constancy of the preparation coat is thus measured by means of a resistance measurement, and if necessary by means of a desired value/actual value comparison in the concentration regulator 81 and a frequency converter which drives the motor 83 of the dosage pump 71 for the preparation oil.
In the embodiment of FIG. 2, the foam container is somewhat different in design from FIG. 1. The foam container 30 is made in the form of a rectangular or cylindrical funnel to which the foam producer 50, 50' is connected in continuation of its external form, but separated by a commissure 38. The narrow output opening 35 of the foam container 3 is here included into the foam producer 50, 50', so that the foam container 3 is open over the full cross-section at the commissure 38.
The foam producer consists of two half-cups 50, 50' which are able to move apart in horizontal direction, along the commissure 38. As a result, the lower part of the foam container 30 becomes accessible for spinning, so that the dropping filaments F can be seized and be inserted into the yarn guide for further processing. Once this has been accomplished, the two half-cups 50, 50' of the foam producer are again joined together so they enclose the filaments F and so that the foam container 30 is closed with the exception of the output opening 35 for the filaments F.
Either of the two half cups 50, 50' is made as an independent foam producer and is connected to an air feed 51 as well as to a liquid feed 52. These feed lines are advantageously elastic so that the two half-cups 50, 50' can be moved apart. The two half-cups 50, 50' are mounted advantageously on an axis vertically to the commissure 38 at their one end for this, so that the half-cups 50, 50' can be opened for the insertion of the filaments F. In each of the half-cups 50, 50', sintered metal plugs 52 are installed through which the air and the liquid are fed. Instead of going through the sintered metal plugs 53, the air can also be fed through a plate or any other form of a body made of sintered metal. Preferably however, the commercially available sintered metal plugs are used for the air arrival.
The utilization of sintered material produces extremely good mixing of the liquid with gas, preferably air, into foam. Other fine-porous elements can of course also be used for the gas arrival into the liquid, such as sieves, nozzle plates, etc.
The liquid level 54 in the foam producer 50, 50' is controlled by a level limiter 37 to ensure uniform foam production. The simplest type of such a level limiter 37 is shown in FIG. 2 in the form of an overflow spillway. Instead of the overflow spillway 37, a probe can be provided which controls the arrival of liquid. The foam produced in this manner rises into the foam container 30 while the filaments F run through the foam container in the counter-current and leave through the output opening 35.
The upper part of the foam container 30 is made in similar manner as in the described embodiment according to FIG. 1. Here too, the edge of the opening 31 is made in the form of an overflow spillway so that the liquid forming again collects and is able to drip off over this edge to be caught and to be reintroduced into the circuit for foam production.
The sensor 4 regulates the level of the foam inside container 30, but it may become necessary to take further measures so that the foam surface is even and so that thus all the filaments F go through the same cooling path SB through the foam. To avoid the formation of a foam mound at the input opening 31 of the foam container, a device for the smoothing of the foam surface can be provided additionally. In the embodiment shown, a suction channel 21 is provided which removes such a foam mound or prevents the formation of such a foam mound by means of a slight air stream.
The distance S from the nozzle plate 2 is shown substantially shorter than in FIG. 1. As mentioned earlier, this distance depends on the filament speed and the titer of filaments F. A certain distance S must however be respected, since the foam must not touch the nozzle plate 2 in order to avoid undesirable cooling of same by the foam. Such a device 21 for the smoothing of the foam surface also makes a certain distance from the nozzle plate necessary.
It should be appreciated by those skilled in the art that various modifications and variations can be made in the present invention without departing from the scope and spirit of the invention. It is intended that the present invention cover such modifications and variations as come within the scope of the appended claims and their equivalents. | For the cooling of melt-extruded filaments of fiber-forming polymers spun from nozzle in molten form, said filaments are exposed to a medium prepared in foam form. The filaments emerging from the spinning nozzle are taken to the cooling area through said foam before passing on to a further process. The cooling medium, consisting of a liquid, is prepared by the addition of a gas. | 3 |
RELATED APPLICATION DATA
This application claims priority of U.S. Provisional Application No. 60/891,794 filed on Feb. 27, 2007, which is incorporated herein by reference in its entirety.
FIELD OF THE INVENTION
The present invention relates to medical markers and, more particularly, to a deformable marker device that can be adapted to a surface of a human or animal body and/or placed onto said body.
BACKGROUND OF THE INVENTION
In medical navigation, markers are typically attached to an object to be tracked. These medical markers may be passive markers (e.g., light reflecting markers), active markers (e.g., light generating markers), or magnetic markers (e.g., coils). By tracking a location of the marker, the location of the object attached thereto also can be tracked.
Conventional marker devices are not deformable. Instead, the individual marker elements of the marker device have a fixed position relative to each other, such as is for example known from so-called reference stars.
SUMMARY OF THE INVENTION
A deformable marker device in accordance with the present invention preferably comprises a plurality of marker elements connected to each other, wherein the marker elements can be moved relative to each other. The markers can be configured such that they are impermeable to waves and/or radiation used in medical analysis (e.g., x-ray radiation), reflect said waves and/or radiation (e.g., infrared light or ultrasound) or emit waves and/or radiation themselves (e.g., light or infrared light). Images obtained using such imaging techniques (x-ray imaging, infrared light, ultrasound, etc.) are referred to herein as a medical image. The interaction between the marker elements and the waves and/or radiation can be verified by detection devices (e.g., x-ray radiation detectors or light-sensitive sensors).
The deformability of the marker device is preferably achieved using a connecting means that connects the marker elements. The connecting means, for example, can be flexible (e.g., a material) and/or jointed (e.g., a mechanical joint connection between the marker elements). The distance between at least some of the marker elements can be variable. This is the case, for example, if the connecting means is a flexible cloth. The connecting means can, but need not, be elastic. The term “can be moved” means that the marker spheres can be moved relative to each other by a person, without a tool, by applying a minor or normal force, without destroying or damaging the connecting means.
The marker device is preferably used to simplify the determination of a three-dimensional model of an anatomical structure from two two-dimensional images. In particular, the marker device can simplify the determination of correspondence points, wherein correspondence points can be used to determine the three-dimensional position of object points of a structure from two two-dimensional images of the structure from two different directions (in accordance with the principles of epipolar geometry). In particular, the marker device in accordance with the invention can enable the determination of a so-called fundamental or essential matrix (or also localization matrix), which describes properties of the geometry forming the basis of the at least two images. Further information regarding epipolar geometry and determining correspondence points can be found in co-pending U.S. application Ser. No. 12/029,716 filed on Feb. 12, 2008 and titled “Determining a Three-dimensional Model of a Rim of an Anatomical Structure”, the contents of which is hereby incorporated by reference in its entirety.
Conventional localization techniques for determining a localization matrix use rigid objects for which the geometric relationship between the markers is exactly known. A deformable, in particular flexible marker device can be used in accordance with the invention as a localizer, wherein in accordance with one embodiment, the marker elements are visible in x-ray images. For a localization method, in particular for determining the localization matrix in accordance with the principles of epipolar geometry, the relative position between the marker elements should remain the same in the images. Knowledge of the exact geometric relationship between all of the marker elements is not compulsory.
A localization algorithm can be used to determine the localization matrix, for example, by extracting relative camera movement from pairs of correspondence points, as is known from the field of “stereovision”. Such algorithms are known and can be used to extract three-dimensional information from video scenes (i.e., a sequence of images recorded by a moving camera), satellite images or images achieved by a specific stereo configuration (e.g., two cameras aligned in parallel that simultaneously capture images). Examples of such algorithms include the eight-point algorithm (Longuit-Higgins) or the five-point algorithm (Stewénius/Engels/Nistér), which is preferably used. If the algorithms are used for video recordings or other “actual” images captured by a conventional lens system, image features such as edges and grey-color values are typically used to automatically find the matching correspondences (e.g., an edge of a traffic sign in a first image will correspond to the same edge in a second image). A different approach is preferred for x-ray images, since edge information is usually difficult to determine or unreliable because the images have a translucent or transparent property and/or because organic objects are rounded. The latter is in contrast to typical video recordings, which, for example, show buildings or cars that have identifiable edges.
In accordance with an aspect of the invention, marker elements are inserted into the image so as to artificially produce “prominent” image portions that can be used as correspondence points. In particular, this enables the correspondence points to be automatically detected.
When analogously using the marker device (e.g., the marker device is attached or adapted to a human or animal body), at least some (preferably most) of the marker elements are preferably spaced apart from each other, while the marker elements also can be moved relative to each other. The connecting means can be configured such that the marker elements assume predetermined positions when the marker device is spread out. The marker device preferably is designed flat.
Preferably, at least two of the marker elements are held at a fixed distance by the connecting means. To this end, the connecting means can be stiffened between these two marker elements or can comprise a rigid connecting member having a marker element attached to each of its ends. The known, fixed distance is preferably used to calibrate, in particular gauge, the geometry of the imaged object. The localization matrix can be gauged in this way. The distance between the remaining marker elements can be variable.
The markers preferably have differing shapes and/or sizes. There can be at least two groups of markers, wherein the shape and/or size within the group is the same and the markers belonging to different groups differ in shape and/or size. Preferably, the at least two markers that are fixedly spaced apart from each other differ in shape and/or size from the remaining markers, or belong to a group of markers that differ in shape and/or size from the majority of the marker elements.
The deformable marker device is preferably wound or attached at least partially around a part of a human or animal body. This means that when said part of the body is recorded, a first portion of the marker elements are then situated in front of the part of the human or animal body from the viewing direction of the imaging apparatus, and a second portion of the marker elements are situated behind the part of the human or animal body. The marker elements are preferably characteristically different in their shape, size and/or arrangement, such that it is possible to tell from the image which marker elements are in front of the part of the body and which are behind the part of the body. For instance, a different arrangement is given if a location of a foreground marker element relative to neighboring foreground marker elements differs from a location of a background marker element relative to neighboring background marker elements. The surrounded part of the body is also referred to as the “inner region”, since it lies within the region surrounded by the marker device. A characteristic arrangement, for example, would be an arrangement in lines, wherein the upper and lower line are in the foreground and the middle line is in the background. Alternatively or additionally, the marker elements in the foreground, for example, may be arranged in a zigzag shape, while the marker elements in the background may be arranged linearly. Another alternative would be for the marker elements arranged in the foreground to be cube-shaped, while the marker elements arranged in the background can be spherical, resulting in square or round areas in the image that allow the markers to be identified as foreground markers or background markers. Lastly, the marker elements arranged in the background, for example, can have a significantly different size relative to the marker elements arranged in the foreground.
The connecting means also can be designed such that movement of the marker elements in a first direction is easier than movement of the marker elements in a direction perpendicular to the first direction. The marker device, for example, can be designed such that it is easy to deform the marker device into the shape of a cylindrical cloak, while a relative movement of the marker elements in the direction of the cylindrical axis requires a greater force to be applied. This increases the stability of the marker device.
BRIEF DESCRIPTION OF THE DRAWINGS
The forgoing and other features of the invention are hereinafter discussed with reference to the drawing.
FIG. 1 shows an exemplary arrangement of marker elements in a marker device in accordance with the invention.
FIG. 2 shows an exemplary x-ray recording of a pelvis, around which a marker device in accordance with the invention has been wound.
FIG. 3 shows another exemplary x-ray recording under the same conditions as FIG. 2 but from a different direction.
DETAILED DESCRIPTION
FIG. 1 shows a schematic arrangement of exemplary marker elements, which are shown as black circular areas 10 and 20 attached along strips a, b and c. The marker elements are preferably designed as marker spheres that are divided into two groups of different diameters. In the given example, the diameters measure 5 millimeters and 9 millimeters, and the marker spheres along a strip are each spaced apart by 2.5 centimeters. The sizes (diameters) of the marker elements can be arbitrarily selected. They can be larger than 1 millimeter and smaller than 3 centimeters. The distance between the marker elements within a strip can be larger than 2 millimeters and smaller than 10 centimeters. In the given example, the distance between the center points of the marker elements in the upper strip a and lower strip c measures 16.7 centimeters. This is purely by way of example. The distance can be greater than 3 centimeters and less than 30 centimeters. The outer dimensions of the arrangement shown in FIG. 1 measure approximately 20×30 centimeters and are also purely by way of example.
In accordance with one embodiment of the invention, marker elements are arranged flat and connected via a flat cloth 30 . The marker elements can be attached to predetermined positions on the flat cloth. Alternatively or in addition to cloth 30 , the marker elements may be connected to one another via a mechanical joint 31 (e.g., a hinge joint or other joint that enables movement in a first direction, but not in a direction perpendicular to the first direction, etc.). A hinge joint, for example, can include connecting elements (e.g., a first part and a second part) that are coupled together by a common shaft or the like. Such joints are well know and will not be further described herein.
The cloth comprising the marker elements can be wound around a part of the body of a (human or animal) patient in the manner of a kidney belt or in the manner of a cuff. The flat cloth 30 shown in FIG. 1 , for example, can be shaped into a cylindrical cloak, wherein the strips a and c should be on the front half of the cylindrical cloak, while the strip b should be on the rear half of the cylindrical cloak. The cloth shown in FIG. 1 thus can be double-layered, wherein the strips a and c form part of the front layer and the strip b forms part of the rear layer. In other words, the strips a and c represent a view of the cuff-shaped marker device from the front, and the strip b represents a view from the rear.
FIG. 2 is an x-ray recording of a pelvis. In front of the x-ray recording, a belt configured in accordance with the device of FIG. 1 has been wound around the patient's pelvis and attached to the human body (e.g., by a waistband, buttons and/or by designing the cloth to be elastic) and/or is held on the human body by tension. The marker elements 10 and 20 , which are visible in the x-ray recordings, can again be seen as black circles in FIG. 2 in their characteristic arrangement known from FIG. 1 . They are arranged along the lines a, b and c, which correspond to the strips a, b and c in FIG. 1 . The lines are clearly identifiable, since the distance between the marker elements within a line is preferably less than the distance between the lines. Further, the strips a, b and c are arranged such that marker elements do not lie one directly behind the other when the device is formed as a closed area (e.g., when formed as an area resembling a cylinder or elliptic cylinder, or other shape that conforms to an outer surface of the patient's body).
The larger marker spheres 20 are conspicuous and clearly distinguished from the smaller marker spheres 10 . A rod 40 also can be seen, which is not shown in FIG. 1 . The rod 40 preferably consists of a material that is at least partially permeable to x-rays, e.g., a plastic such as PVC. The rod 40 is preferably designed rigid and defines a fixed distance between two marker spheres situated on the same side of the part of the body. In the given example, this is the connection between the two large marker spheres 20 a and 20 c situated on the front side of the pelvis. Using a spacer 40 allows the localization matrix to be calibrated or gauged in terms of size.
While FIG. 2 shows a frontal recording of the pelvis, FIG. 3 is an x-ray recording taken from the view of the observer from obliquely front-right. In other words, the right-hand hip joint has been rotated forwards while the recording apparatus remains stationary.
The marker spheres corresponding to each other in FIGS. 2 and 3 can be easily determined. The large marker spheres 20 can serve as starting points. The large marker sphere 20 a , for example, has five small marker spheres 10 a located to its right. Each of the identical marker spheres have been provided with reference signs in FIGS. 2 and 3 . The left-hand marker sphere of the two large marker spheres 20 b in FIG. 2 can be seen in the middle row b in FIG. 3 . The large marker spheres 20 a and 20 c are shown in both images. The translucently visible spacer 40 provides an additional identification aid.
Due to the relative shift in position between the marker spheres, it is possible when comparing FIGS. 2 and 3 to determine the different recording geometry in each case. As can be seen, the middle group of markers ( 10 b , 20 b ) is shifted to the right from FIG. 2 to FIG. 3 relative to the upper ( 10 a , 20 a ) and lower ( 10 c , 20 c ) group of markers. This is due to the fact that the marker spheres of the strip b are behind the imaged pelvis, while the marker spheres of the strips a and c are in front of the imaged pelvis. Changing the imaging direction appears to shift the position of the marker spheres in the images. In reality, however, the marker spheres are stationary relative to the anatomical structure while the two x-ray recordings are taken, since the marker device is fixedly strapped to the patient.
The changed imaging direction can be determined from the relative shift from FIG. 2 to FIG. 3 . For example the imaging direction can be determined based on the shift of the spheres 20 b relative to the spheres 20 a and 20 c , and on the known distance between the marker spheres 20 a and 20 c . The distances between the marker spheres within a group or “line” also can be adduced, particularly if the cloth is a flexible but inelastic cloth.
In summary, it is possible to determine information on the change in the imaging conditions from image to image, in particular on the change in the imaging direction, from the images of the marker elements. The so-called essential matrix or localization matrix can be determined, which contains essential information on the imaging geometry that changes from image to image. If this matrix is determined, then it is possible to produce three-dimensional models of the imaged anatomical structure from the two images, based on the principle of epipolar geometry.
As shown in FIG. 2 , the middle row b of markers contains two large marker spheres 20 b . This is only one example embodiment. In accordance with another embodiment, one larger marker sphere is also sufficient. Arranging the larger marker spheres 20 b to the left and right of the center lying at the rod 40 simplifies handling. In particular, the belt does not have to be rotated about an axis running normal to and through the center in FIG. 1 , depending on whether the left-hand or right-hand side of the anatomical structure is to be more precisely examined.
If a recording protocol is defined for the x-ray recording in which the part to be treated is to be rotated forwards or backwards, then it is possible to automatically determine which side is the side to be treated from the shift in the rows of marker spheres relative to each other. In other words, due to the recording protocol, the side which is to be treated can be deduced from the polarity of the rotational angle between the two images, as determined from the images. This can be utilized within the framework of an evaluation software.
Although the invention has been shown and described with respect to a certain preferred embodiment or embodiments, it is obvious that equivalent alterations and modifications will occur to others skilled in the art upon the reading and understanding of this specification and the annexed drawings. In particular regard to the various functions performed by the above described elements (components, assemblies, devices, compositions, etc.), the terms (including a reference to a “means”) used to describe such elements are intended to correspond, unless otherwise indicated, to any element which performs the specified function of the described element (i.e., that is functionally equivalent), even though not structurally equivalent to the disclosed structure which performs the function in the herein illustrated exemplary embodiment or embodiments of the invention. In addition, while a particular feature of the invention may have been described above with respect to only one or more of several illustrated embodiments, such feature may be combined with one or more other features of the other embodiments, as may be desired and advantageous for any given or particular application. | A deformable marker device for adapting to a human or animal body includes a plurality of marker elements, and a connecting device that connects at least some marker elements of the plurality of marker elements to each other. The connecting device enables the at least some marker elements to be moved relative to each other so as to adapt a shape of the marker device to a course of a curved surface. | 0 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a continuation of U.S. patent application Ser. No. 12/773,504, filed May 4, 2010, the entire contents of which are hereby incorporated by reference.
TECHNICAL FIELD
This invention relates to managing power delivery, and more particularly to managing power generated from renewable resources.
BACKGROUND
Renewable resources, such as wind, wave, and solar energy, are an attractive alternative to the use of fossil fuels in generating power due to their renewable nature and clean operation. However, unlike thermal power plants (e.g., coal-fired or natural gas fired plants), generally, the amount of wave, wind, or solar energy available at any given time can not be controlled or reliably predicted. Further, due to the inherent variability of these renewable energy sources, (e.g., wind gusts and/or directional changes, weather conditions, etc.), the instantaneous power output of an associated power generator (e.g., a wind turbine) may vary significantly from one second to the next.
SUMMARY
In a first aspect, a power delivery rate from a renewable power source to a load is managed by determining, by processing circuitry, a change in a power generation rate, determining, by the processing circuitry, whether the change in the power generation rate exceeds a limit, and then, adjusting, by control circuitry, a power transfer rate to or from a power storage device, such that the adjusting is sufficient to prevent the power delivery rate from exceeding the limit. Other implementations of this aspect include corresponding systems, apparatus, and computer programs, configured to perform the actions of the methods, encoded on computer storage devices.
In another aspect, a control system for a bidirectional power device coupled to a dynamic power source converting renewable energy into electrical power includes: a storage device having stored thereon machine-readable instructions specifying a ramp rate control operation; a set of I/O ports configured to receive information regarding the bidirectional power device and the dynamic power source; a processor coupled to the set of I/O ports and the storage device and configured to execute the machine-readable instructions to perform operations including: determining a change in a power generation rate; determining whether the change in the power generation rate exceeds a limit; and then, adjusting a power transfer rate to or from the bidirectional power device, wherein the adjusting is sufficient to prevent the power delivery rate from exceeding the limit.
These and other embodiments can each optionally include one or more of the following features. Managing the power delivery rate can include determining, by the processing circuitry, a present state-of-charge of the power storage device, and adjusting the limit, by the processing circuitry, based on the present state-of-charge of the power storage device. The limit can include a ramp rate limit associated with increases in the power generation rate and adjusting the limit can include: setting the ramp rate limit to a minimum value if the present state-of-charge is less than a minimum state-of-charge; setting the ramp rate to a maximum value if the present state-of-charge is greater than a maximum state-of-charge; and setting the ramp rate to a value between the minimum value and the maximum value if the present state-of-charge is neither less than the minimum state-of-charge nor greater than the maximum state-of-charge. The limit can include a ramp rate limit associated with decreases in the power generation rate and adjusting the limit can include: setting the ramp rate limit to a minimum value if the present state-of-charge is greater than a maximum state-of-charge; setting the ramp rate to a maximum value if the present state-of-charge is less than a minimum state-of-charge; and setting the ramp rate to a value between the minimum value and the maximum value if the present state-of-charge is neither less than the minimum state-of-charge nor greater than the maximum state-of-charge. The limit can include a first ramp rate associated with increases in the power generation rate and a second ramp rate associated with decreases in the power generation rate, and adjusting the limit can include: setting the first ramp rate to a maximum value and the second ramp rate to a minimum value if the present state-of-charge exceeds a maximum state-of-charge. Adjusting the power transfer rate to or from the power storage device can include: increasing the power transfer rate from the power storage device to match a decrease in the power generation rate in excess of the second ramp rate; and setting the power transfer rate to the power storage device to match the increase in the power generation rate in excess of the first ramp rate. The limit can include a first ramp rate associated with increases in the power generation rate and a second ramp rate associated with decreases in the power generation rate, and adjusting the limit can include: setting the first ramp rate to a minimum value and the second ramp rate to a maximum value if the present state-of-charge falls below a minimum state-of-charge. Adjusting the power transfer rate to or from the power storage device can include: increasing the power transfer rate to the power storage device to match an increase in the power generation rate in excess of the first ramp rate; and setting the power transfer rate from the power storage device to match the decrease in the power generation rate in excess of the second ramp rate.
The details of one or more embodiments of the invention are set forth in the accompanying drawings and the description below. Other features, objects, and advantages of the invention will be apparent from the description and drawings, and from the claims.
DESCRIPTION OF DRAWINGS
FIG. 1 illustrates a wind farm including a power management system.
FIG. 2 illustrates an exemplar power management system.
FIG. 3 illustrates an exemplar control system for a power management system.
FIG. 4 illustrates a graphical user interface.
FIG. 5 illustrates an exemplar ramp rate bias control function.
FIG. 6 illustrates an exemplar photovoltaic park including a power management system.
FIG. 7 illustrates an exemplar wave park including a power management system.
Like reference symbols in the various drawings indicate like elements.
DETAILED DESCRIPTION
Rapid increases in power output can be managed to some degree by manipulating the wind turbine and/or its controls (e.g., yawing or tilting the plane of rotation, varying the blade pitch, using a passive/active stall mechanism, controlling the output of a variable-speed generator, etc.). However, intentionally reducing power output despite the availability of wind energy (i.e., curtailment) decreases the overall energy efficiency of the system. Similarly, preemptively reducing the power output of a wind turbine generator so that a sudden decrease in wind energy appears less abrupt also decreases the overall energy efficiency of the system. Such reductions in power output may be necessary to avoid exceeding a ramp rate limit for delivering power to a load (e.g., a utility grid) and/or for accommodating a power generation schedule based on expected demand.
FIG. 1 illustrates a wind farm 100 including a power management system (PMS) 110 . As described in more detail below, PMS 110 provides energy storage and management to automatically buffer the output of wind turbine generators (WTGs) 120 to distribution network 160 (e.g., a utility grid). In particular, PMS 110 is operable to minimize or eliminate curtailment, smooth overall power output, limit power ramps, and buffer large wind speed excursions (i.e., wind gusts). In instances where frequent wind gusts cause WTGs 120 to trip or go off-line (i.e. a fault event), PMS 110 is further operable to compensate for the sudden disruption in power output by supplementing the power output to avoid or mitigate a ramp rate violation associated with the negative power ramp.
The exemplar wind farm configuration illustrated in FIG. 1 shows PMS 110 coupled to substation 130 through radial feeder 140 of substation main bus 150 (e.g., a 34.5 KV or medium voltage electrical network). WTGs 120 are also coupled to substation main bus 150 through corresponding radial feeders 141 , 142 . Substation 130 couples PMS 110 and WTGs 120 to distribution network 160 (e.g., a high voltage electrical network) via protective relays 131 , 134 , AC switchgears 132 , 135 , and step-up power transformer 133 . Protective relays 131 , 134 and AC switchgears 132 , 135 provide a first level of protection from excessively high voltage or current conditions. In some implementations, substation 130 may also include multiple step-up transformers, breakers, relays, current transducers (CT), potential transducers (PT), communication equipment, etc.
In general, PMS 110 monitors the instantaneous power output from each WTG 120 and adjusts the amount of power delivered to distribution network 160 by storing or supplying power such that the net amount of power delivered to network 160 remains within predetermined limits. In addition, PMS 110 is operable to condition the generated power so as to reduce the variability typically associated with wind generated power (i.e., smoothing). In some implementations, PMS 110 provides a second level of protection to the wind farm components, and/or distribution network 160 and components coupled to the transfer network. For example, in a first implementation, PMS 110 is configured to monitor the quality and characteristics of power being distributed on network 160 and responsive to detecting an out-of-limit condition (e.g., overvoltage, fault, voltage sag, etc.), PMS 110 attempts to compensate by adjusting the transfer of power to distribution network 160 . These and other features are described in further detail below.
Referring now to FIG. 2 , an exemplar implementation of PMS 110 includes intertie skid 210 and control system 200 coupled to inverter/charger 220 for controlling the transfer of power to and from battery bank 230 responsive to the control algorithms executed by the control system. Control system 200 is also coupled to protective relays 240 and AC switchgear 250 to monitor fault conditions and alarms. Control system 200 coordinates the operation of the system components, including inverter/charger 220 and battery bank 230 , monitors the operating environment, provides diagnostic capabilities, and manages the overall system operation in response to setup parameters entered via a status and control interface or human-machine interface (HMI). In some implementations, control system 200 includes remote operation terminals for receiving user programmable parameters related to the wind farm power output and for displaying information related to various monitored parameters. The programmable parameters include, for example, limits and targets associated with power smoothing, power storage, target state-of-charge and corresponding limits, etc.
Intertie skid 210 includes a 34.5 KV to 480/277 V substation transformer 211 , a high voltage fused switch 212 , and a low voltage switchboard 213 and serves to couple the rest of PMS 110 to substation 130 via substation main bus 150 . The 34.5 KV power is provided to intertie skid 210 from a fuse cutout 214 attached to substation main bus 150 . Three #4/0 35 KV shielded cables 215 are protected by the fuse element in fuse cutout 214 and are terminated in a high voltage (HV) fused switch 212 . Fused switch 212 includes station type lightning arrestors on the incoming feed. The fuses in fused switch 212 are sized to protect transformer 211 . The primary of transformer 211 is fed by three #1/0 35 KV shielded cables 217 . The secondary of transformer 211 is connected to low voltage switchboard 213 via fifteen 750 kcmil 600 V cables (5 per phase) and a 300 Amp trip (100% rated) main breaker.
As illustrated in FIG. 3 , control system 200 includes supervisory control and data acquisition (SCADA) system 310 , user interface PC (UI-PC) 330 , real-time control processor (RT-PC) 340 , and various controllers and sensors. UI-PC 330 provides a primary user interface to accept user requests, provide warning or error indications, and to receive user programmable control parameters. RT-PC 340 coordinates the remaining elements of PMS 110 . Various control elements are responsible for controlling and monitoring specific system sub-functions. The various control elements are connected via Ethernet network 305 . Each link is monitored for correct operation via the use of semaphores which include “deadman” timers. If a link becomes impaired or fails, the system takes appropriate action, including, for example, shutting down PMS 110 if the control operation is compromised.
RT-PC 340 controls inverter/charger 220 using the parameters received from the user via UI-PC 330 , data from inverter/charger 220 , and data from the other components, including, for example, current transducers, potential transducers, curtailment signals, etc. A curtailment signal represents a request from the utility operator to curtail power output from the wind farm via a curtailment interface 341 and/or serial interface 342 . For example, curtailment interface 341 is coupled to a 4-20 mA current loop interface to receive a curtailment request. The detected current level at the interface is proportional to the total power output from the wind farm such that a 20 mA signal represents a request for full power output and 4 mA represents a request for full curtailment. RT-PC 340 also receives an Inter-Range Instrumentation Group (IRIG) signal via serial interface 342 . The IRIG signal provides a reliable time reference.
RT-PC 340 also includes input-output (I/O) modules 343 (e.g., I/O FPGA cards) for receiving currents and potentials from corresponding transducers via optically-isolated signal conditioners (OISC) 344 . I/O modules 343 are coupled together to allow data to be transmitted and received between the modules, and thus, allow them to perform as a single unit. I/O modules 343 are also coupled directly to inverter/charger 220 via fiber optic Ethernet interface 345 .
Battery bank 230 includes multiple dry cell battery packs connected in a parallel/series configuration to create a single battery bank having a predetermined nominal voltage and Amp-Hour capacity. For example, in some implementations the battery bank includes 72 12-Volt battery packs connected in series to create a battery bank having a nominal voltage of 864 Volts. Each battery pack includes 15 12-Volt dry cell batteries connected in parallel. The batteries are connected in such a way as to ensure that each battery in each battery pack receives a similar or equal voltage at a positive terminal of the respective battery relative to a single reference point. In some implementations, connections are made using precision cabling to provide a uniform DC environment. For example, U.S. patent application Ser. No. 11/549,013, incorporated herein by reference, describes batteries connected in parallel via respective and distinct conductive paths, each conductive path having an under-load resistance differing from an under-load resistance of each other path by less than about 1 milli-ohm.
Battery bank 230 is monitored by programmable automation controller (PAC) 320 . PAC 320 includes multiple I/O modules 321 coupled to the outputs of signal conditioning boards 323 . Signal conditioning boards 323 provide optical isolation for multiple battery sense points in battery bank 230 . For example, each battery pack (i.e., parallel string of batteries) includes a voltage sensor 322 coupled in parallel with the battery pack. The output of each voltage sensor 322 is coupled to a corresponding one of eight signal conditioning boards 323 , each board having nine or more differential input channels and one or more outputs. PAC 320 monitors battery bank 320 gathering battery data and sending it to RT-PC 340 periodically (e.g., once per second). In some implementations, PAC 320 includes a compact chassis housing a single-board computer, multiple FPGA-based data acquisition modules, serial interfaces, and Ethernet interfaces (e.g., a National Instruments Corp. CompactRIO system).
Inverter/Charger 220 includes a three-phase sinusoidal pulse-width modulated inverter operating in current-controlled mode to generate three-phase sinusoidal output currents with low total harmonic distortion (THD). Insulated-gate bipolar transistor (IGBT) modules 221 are used as switching devices and are coupled to battery bank 230 via an LF/CF-filter 222 to reduce the ripple current in the DC-source. Inverter/Charger 220 enables the bidirectional transfer of power between battery bank 230 and distribution network 160 via intertie skid 210 and substation 130 . For example, depending upon the wind farm grid status, battery status, and the operating parameters, inverter/charger 230 transfers power between a 480 VAC three phase interface with intertie skid 210 and battery bank 230 . Inverter/Charger control signals are received from Embedded Control and Acquisition Device (ECAD) 350 which is coupled to RT-PC 340 via an Ethernet link. ECAD 350 receives input commands, including, for example, target levels for active (P) and reactive (Q) power, wind farm grid status information, from control points in the grid and intertie skid. ECAD 350 is configured to respond directly to grid disturbances requiring immediate action without any intervention from other components within control system 200 to minimize response time.
Referring now to FIG. 4 , an exemplary setup/administration screen 400 of UI-PC 330 is illustrated. This screen enables the user to configure system parameters including, for example, the target percent of storage capacity to use in smoothing 410 and curtailment 420 operations and the maximum rates at which the power flow to the grid is allowed to change during smoothing 430 and excursion 440 control operations.
The wind smoothing parameters define the operating limits for smoothing operations including threshold rates of change and a percent of storage capacity to use. For example, if 10% is selected for “% Storage,” battery bank 230 will be charged or discharged 5% around the nominal operating point (i.e., target state-of-charge) to provide smoothing operations. Further, if the “Smoothing Rate” parameter is set to 0.1 MW/min, the system will not attempt to smooth transitions which occur below this rate. The ramp control parameters define the maximum rate at which the net power output to distribution network 160 is allowed to change in any direction. In some implementations, a single value sets both positive (increasing output) and negative (decreasing output) ramp rate limits. As described in more detail below, the wind smoothing and ramp control algorithms in some implementations include control mechanisms to keep the batteries in the normal operating range, limiting the smoothing and excursion operations as the battery state of charge nears normal operating limits (including, for example, maximum charge capacity and/or maximum depletion).
In addition to smoothing and ramp rate parameters, screen 400 , in some implementations, enables the user to configure a curtailment capture parameter 420 to set the percent storage capacity to be used for storing power that would otherwise be curtailed by the wind turbine generators. For example, setting the capture parameter 420 to 10% reserves 10% of battery bank capacity to store energy in response to curtailment requests from a utility operator or utility grid control system. Power that would otherwise be curtailed is stored by PMS 110 within predetermined operating parameters (i.e., maximum capacity and current battery state-of-charge).
FIG. 5 illustrates an exemplar implementation of PMS 110 operating under a first set of conditions. For example, PMS 110 is configured to buffer wind power variability by providing a steady output of power at rates changing no more than a maximum allowable ramp rate for excursion control (e.g., sudden ramps in power due to, for example, wind gusts) and a smoothing ramp rate during smoothing control, thus improving output reliability while enabling more effective grid management and creating more easily dispatchable power. In this implementation, the algorithms implemented by control system 200 are based on parameters that represent the second to second power output of the wind farm. Other time scales may be used for power sources having more or less variability or for coarser control of power output.
The WTG parameter represents the total wind turbine output (WTG.sub.1+WTG.sub.2+ . . . +WTG.sub.n) at time t (seconds). The upward-ramp-rate (UpRR) and the downward-ramp-rate (DownRR) parameters represent the maximum allowable rate of change in power output (e.g., KW/sec) from wind farm 100 . In some implementations, the UpRR and DownRR values are fixed (e.g., for excursion mitigation without smoothing or for constant smoothing). In other implementations, such as the present example, the UpRR and DownRR values are variable between a minimum (e.g., zero, a smoothing limit (SmthRR), a percentage of the maximum, etc.) and a maximum (e.g., a maximum input rate of PMS 110 , an Excursion ramp rate limit (ExcRR), a percentage thereof, etc.) and depend on the available capacity of PMS 110 . The XP parameter represents the amount of power required (in or out) from PMS 110 to mitigate UpRR or DownRR violations. The SystemOut parameter represents the sum of WTG and XP at time t (WTG.sub.t+XP.sub.t).
The DeltaP parameter represents the difference between WTG at time t and SystemOut at time t−1 (WTG.sub.t−SystemOut.sub.t−1). DeltaP can also be understood to represent the potential net change in SystemOut assuming PMS 110 stopped contributing at time t (i.e., DeltaP.sub.t=WTG.sub.t−WTG.sub.t−1−XP.sub.t−1). A negative DeltaP indicates a potential decrease in system output and a positive DeltaP indicates a potential increase in system output. If the potential increase/decrease in system output would not violate either UpRR or DownRR, no contribution by XP is necessary at time t. However, if |DeltaP| is greater than UpRR or |DownRR|, PMS 110 will contribute by absorbing or providing the difference in magnitude to avoid or mitigate ramp rate violations and/or to smooth power output, depending on available system capacity.
In some implementations, the maximum amount of power absorbed or supplied by PMS 110 is gradually reduced as battery bank 230 approaches a maximum state of charge or minimum state of charge. In such a case, XP is limited to the lesser of the scaled maximum output/input and the required contribution to avoid the ramp rate violation (i.e., |XP|=MIN(|ScaledPowerLimit|, |DeltaP−Up/DownRR|)). Such an approach may be useful, for example, to mitigate the ramp rate violations over a longer period of time than would otherwise be possible due to capacity limitations and/or to extend the useful life of PMS 110 .
The XP_Energy parameter represents the amount of energy required to be transferred to/from PMS 110 at time t to absorb/supply XP. In some implementations, XP_Energy is determined using trapezoidal integration to find the area under the curve: [XP.sub.t−1+XP.sub.t]/2*(1/3600). Finally, the SOC.sub.t parameter represents the state of charge of battery bank 230 at time t (SOC.sub.t−1−(XP_Energy/1000*SystemSize), where SystemSize represents the capacity of battery bank 230 in MWh).
The following pseudo-code illustrates an example algorithm for controlling the amount of power (XP) absorbed or supplied by PMS 110 . Other pseudo-code, languages, operations, orders of operations, and/or numbers may be used.
PMS Power Transfer Control Logic
XP =
power required from XP system at time t (positive = sourcing; negative =
absorbing) to maintain UpRR or DownRR
DeltaP =
Difference of total system output from time t−1 and total turbine output at
time t (positive indicates a potential net increase in total system output if XP
contribution = 0; negative indicates a potential net decrease in total system
output if XP contribution = 0)
UpRR =
Up ramp rate limit (function of SOC t−1 )
DownRR =
Down ramp rate limit (function of SOC t−1 )
SystemMax =
maximum power input/output for XP system
Power_In =
Scaling factor for maximum power input
Power_Out =
Scaling factor for maximum power output
SOCt =
State of Charge at time t
SOC_Max =
Maximum allowable state of charge
SOC_Min =
Minimum allowable state of charge
Rech_DB =
value used to set the upper limit to begin scaling power input
Disch_DB =
value used to set the lower limit to begin scaling power output
Rech_Exp =
exponent used to define curve for allowable power input after SOC t exceeds
Rech_DB
Disch_Exp =
exponent used to define curve for allowable power output after SOC t exceeds
Disch_DB
IF DeltaP > UpRR THEN
IF SOC t > SOC_Max THEN
Power_In = 0
ELSEIF SOC t < Rech_DB THEN
Power_In = 1
ELSE
Power_In = 1 − [(SOC t − Rech_DB)/(SOC_Max − Rech_DB)]{circumflex over ( )}Rech_Exp
ENDIF
IF (DeltaP − UpRR) > Power_In*SystemMax THEN
XP = − Power_In*SystemMax
ELSE
XP = −(DeltaP − UpRR)
ENDIF
ELSEIF DeltaP < DownRR THEN
IF SOC t < SOC_Min THEN
Power_Out = 0
ELSEIF SOC t > Disch_DB THEN
Power_Out = 1
ELSE
Power_Out = 1 − [(Disch_DB − SOC t )/(Disch_DB − SOC_Min){circumflex over ( )}Disch_Exp
ENDIF
IF (DownRR − DeltaP) > Power_Out*SystemMax THEN
XP = Power_Out*SystemMax
ELSE
XP = (DownRR − DeltaP)
ENDIF
ELSE
XP = 0
ENDIF
Thus, if, without contribution from PMS 110 , the net change in system output from time t−1 to time t would be greater than the up ramp rate limit, PMS 110 absorbs (i.e., negative XP value): (i) nothing if SOC.sub.t is greater than the maximum allowable state of charge (i.e., XP=Power_In*SystemMax=0 since DeltaP−UpRR would be greater than zero) and the ramp rate violation is allowed to occur; (ii) the required amount to prevent a violation, up to the system maximum if SOC.sub.t is less than the set point for scaling down power input; or (iii) the required amount to prevent a violation, up to the scaled system maximum (i.e., Power_In*SystemMax).
Further, if, without contribution from PMS 110 , the net change in system output from time t−1 to time t would be less than the down ramp rate limit (i.e., exceeding a negative rate of change limit), PMS 110 provides (i.e., positive XP value): (i) nothing if SOC.sub.t is less than the minimum allowable state of charge (i.e., XP=Power_Out*SystemMax=0 since DownRR−DeltaP would be greater than zero); (ii) the required amount to prevent a violation, up to the system maximum if SOC.sub.t is greater than the set point for scaling down power output; or (iii) the required amount to prevent a violation, up to the scaled system maximum (i.e., Power_Out*SystemMax).
As described above, in some implementations, the values for UpRR and DownRR depend on the state-of-charge (SOC) of the battery bank at time t. FIG. 5 illustrates an exemplary ramp rate control chart 500 for adjusting UpRR and DownRR according to the current SOC of the battery bank (e.g., battery bank 230 of FIG. 2 ). In this example, a target SOC value 530 (e.g., 50%) serves as a reference point for the UpRR and DownRR control algorithms. Deadband limits define an area or band where no change is made to the corresponding values (e.g., UpRR 510 and/or DownRR 520 ). Transition limits define the upper and/or lower bounds beyond which the corresponding limit is set to the MinRR or MaxRR value. The ramp rate control algorithms attempt to keep the current SOC within +/−DB of the target SOC by adjusting UpRR and DownRR to increase charging/discharging of the battery bank.
Referring first to positive rates of change in power output from the renewable energy source, UpRR 510 is assigned a value between a minimum ramp rate (MinRR) 511 (e.g., 0% of the maximum desired ramp rate), a secondary ramp rate (SecRR) 512 (e.g., 10% of the maximum desired ramp rate), and a maximum ramp rate 513 (MaxRR) (e.g., 100% of the maximum desired ramp rate) based on the current SOC value. Setting MinRR, SecRR, and MaxRR to pre-programmed percentages of the maximum desired ramp rate allows the ramp rates to be automatically defined based on a single value (e.g., an excursion ramp rate limit, a desired smoothing ramp rate, etc.).
In some implementations, the percentage settings for each of the ramp rates (MinRR, SecRR, MaxRR) and/or the ramp rate values themselves may be entered directly, providing more advanced control. Further, in some implementations, target SOC 530 , and the SOC limits associated with the corresponding ramp rate limits (e.g., UpRR and/or DownRR) are individually configured for up ramp rates and for down ramp rates to provide for additional customization. For example, ramp rate controls and/or limits may be implemented to mitigate only one type of ramp rate violation, such as, for example, an up ramp rate. Such implementations may include an additional PMS 110 , battery bank 230 , or alternate power source, for example, to supplement power output during decreases in WTG total power output.
Referring to UpRR 510 in FIG. 5 , when the current SOC is exactly equal to target SOC 530 , UpRR is equal to SecRR 512 . In this example, UpRR deadband limits 532 and 533 are −5% and 0% of target SOC 530 , respectively. Therefore, while the current SOC remains within this range, UpRR remains equal to SecRR 512 . Beyond this range, UpRR 510 transitions to MinRR 511 or MaxRR 513 depending on the current SOC. For example, if the current SOC drifts below lower DB limit 532 , UpRR 510 will be set to a value between SecRR 512 and MinRR 511 . As a result, PMS 110 will absorb a larger portion of any positive increases in generated power to increase the current SOC. Once the current SOC drifts below lower transition limit 531 , UpRR 510 is set to MinRR 511 . In this example, MinRR 511 is equal to 0% of the allowable ramp rate limit which allows any positive increase in generated power to be redirected to or absorbed by battery bank 230 , increasing the current SOC and resulting in no net increase in power output to the load.
If, however, the current SOC drifts beyond the upper DB limit 533 (which is also the target SOC 530 in this example), UpRR 510 will be set to a value between SecRR 512 and MaxRR 513 . As a result, PMS 110 will absorb less charge during any positive increases in generated power to slow the increase in the current SOC. Consequently, greater increases in generated power or up ramp rates will be seen by the load. Once the current SOC drifts past upper transition limit 534 , UpRR 510 is set to MaxRR 513 . In this example, MaxRR 513 is set to 100% of the allowable ramp rate limit. Some implementations include additional upper DB limits 533 and/or transition limits 534 . For example, in some implementations, MaxRR 513 is set to a value between SecRR and 100% of the allowable ramp rate limit when the current SOC drifts past the first upper transition limit 534 . Once the current SOC drifts past a second upper transition limit 534 (not shown), MaxRR is set to 100% of the allowable ramp rate. In this way, the UpRR control algorithm provides for multiple levels of SOC control and/or ramp rate control.
Referring now to DownRR 520 in FIG. 5 , when the current SOC is exactly equal to target SOC 530 , DownRR is equal to SecRR 522 . In this example, DownRR deadband limits 537 and 536 are 0% and 4% of target SOC, respectively. Therefore, while the current SOC remains within this range, DownRR remains equal to SecRR 522 . Beyond this range, DownRR 520 transitions to MinRR 521 or MaxRR 523 depending on the current SOC. For example, if the current SOC drifts beyond the upper DB limit 536 , DownRR 520 will be set to a value between SecRR 522 and MinRR 521 . As a result, PMS 110 will provide (i.e., discharge) more and more supplemental power to decrease the current SOC by limiting any negative change in power delivered to the load. Once the current SOC drifts past upper transition limit 535 , DownRR 520 is set to MinRR 520 . In this example, MinRR 520 is equal to 0% of the allowable ramp rate limit which allows any decrease in generated power output to be supplied by battery bank 230 , decreasing the current SOC and resulting in no net decrease in power output to the load.
If, however, the current SOC drifts below lower DB limit 537 , DownRR 520 will be set to a value between SecRR 522 and MaxRR 523 . Consequently, PMS 110 will allow greater negative ramp rates to be seen by the load as the current SOC continues to decline. Once the current SOC drifts below lower transition limit 538 , DownRR 520 is set to MaxRR 523 . In this example, MaxRR 523 is set to 100% of the allowable ramp rate limit. Some implementations include additional lower DB limits 538 and/or transition limits 538 . For example, in some implementations, MaxRR 523 is set to a value between SecRR and 100% of the allowable ramp rate limit when the current SOC drifts past the first lower transition limit 538 . Once the current SOC drifts past a second transition limit 538 (not shown), MaxRR 523 is set to 100% of the allowable ramp rate. In this way, the DownRR control algorithm provides for multiple levels of SOC control and/or ramp rate control.
The various combinations of ramp rate limits and SOC limits allow PMS 110 to maximize charge/discharge in the direction that will aggressively push the SOC of battery bank 230 back towards the target SOC while mitigating any ramp rate violations. Further, the UpRR and DownRR control algorithms effectively help maintain system stability and prevent large depth of discharge cycles. Additionally, the probability of violating a ramp rate limit and the severity of any ramp rate violations are greatly reduced assuming PMS 110 is appropriately sized based on the power generation capability of the power source and the associated variability.
In some implementations, the non-transitioning ramp rate is set to zero before the transitioning ramp rate reaches MaxRR. This provides more aggressive control of SOC by maintaining a constant power output during any change in the total generated output opposite the transitioning direction. For example, if UpRR is transitioning towards MaxRR (i.e., current SOC is increasing), DownRR is set to zero such that any decrease in generated power (e.g., WTG) is immediately supplemented by power from PMS 110 (effectively decreasing SOC). Similarly, if DownRR is transitioning towards MaxRR (i.e., current SOC is decreasing), UpRR is set to zero such that any increase in generated power is transferred to PMS 110 (effectively increasing SOC).
The following pseudo-code illustrates another example algorithm for up and down ramp rate control. In this example, the upper DB limit for UpRR is given by SOCTgt+DB and the lower DB limit for DownRR is given by SOCTgt−DB. The lower DB limit for UpRR and the upper DB limit for DownRR are both equal to the target SOC. In addition, MaxRR, SecRR, and MinRR limits are applied to both UpRR and DownRR with corresponding sign notations as appropriate. Determinations are made based on the state of charge at time t−1 rather than the current state of charge so that the results for UpRR and DownRR at time t can be fed forward to the PMS Power Transfer Control Logic described above. Other pseudo-code, languages, operations, orders of operations, and/or numbers may be used.
Up and Down Ramp Rate Control Logic
SOCTgt =
Target SOC
SOCt−1 =
SOC at previous second or t−1
DB =
deadband limit
UpRR =
ramp rate limit applied when the power output from the wind farm is increasing
DownRR =
ramp rate limit applied when the power output from the wind farm is
decreasing
MaxRR =
ramp rate applied if SOC passes outside DB limit
SecRR =
ramp rate used if SOC within DB limit
DroopGain =
gain used when SOC is between SOCTgt and DB; equal to
(MaxRR − SecRR)/DB
IF SOC t−1 < (SOC Tgt − DB) THEN
DownRR = −MaxRR
UpRR = 0
ELSEIF (SOC Tgt − DB) < SOC t−1 < SOC Tgt THEN
DownRR = −(SecRR + (SOC Tgt − SOC t−1 )*DroopGain)
UpRR = SecRR
ELSEIF SOC Tgt < SOC t−1 < (SOC Tgt + DB) THEN
DownRR = −SecRR
UpRR = SecRR + (SOC t−1 − SOC Tgt )*DroopGain
ELSEIF (SOC Tgt + DB) < SOC t−1 THEN
DownRR = 0
UpRR = MaxRR
ENDIF
Additional or fewer ramp rate limits are used in different implementations, depending on the intended purpose and configuration of PMS 110 and/or the renewable power source serviced by PMS 110 . For example, in at least one implementation, MinRR corresponds to 5% of an excursion limit (ExcRR), SecRR corresponds to 10% of ExcRR, and MaxRR corresponds to 70% of ExcRR. UpRR and DownRR are stepped up or down to equal the appropriate ramp rate limit based on the SOC at time t−1. The table below provides an exemplary algorithm for assigning UpRR and DownRR based on the SOC at time t−1, the target SOC, and deadband limits+/−DB1 and +/−DB2.
SOC Region
DownRR
UpRR
SOC t−1 < SOC Tgt − DB2
−ExcRR
0
SOC Tgt − DB2 < SOC < SOC Tgt − DB1
−SmthRR
MinRR
SOC Tgt − DB1 < SOC < SOC Tgt + DB1
−SecRR
SecRR
SOC Tgt + DB1 < SOC < SOC Tgt + DB2
−MinRR
SmthRR
SOC t−1 > SOC Tgt + DB2
0
ExcRR
In other implementations, the ramp rates are individually assigned a value and transition regions are defined to smooth the ramp rate transition from a first value to the next. In addition, some implementations include logic and/or routines for handling certain types of events. For example, frequent and/or severe wind gusts may cause one or more wind turbine generators to trip or go offline to avoid component damage. This event is recognized as a fault event to which PMS 110 responds by providing sufficient power to maintain the current operation (e.g., smoothing and/or ramp rate control). A determination may be made that normal operation will resume momentarily based on information, such as, for example, average sustained wind speeds, frequency of wind gusts, expected changes in weather, and other meteorological data). Based on the determination, the normal ramp rate control algorithm may be suspended allowing the current SOC to drop below the deadband limit without decreasing the power provided. In some implementations, the target SOC is adjusted temporarily according to the weather conditions.
In some implementations, PMS 110 is configured to generate a curtailment signal based on the current SOC of battery bank 230 . For example, in addition to limiting the amount of power absorbed when SOC t-1 >SOC Tgt +DB2, PMS 110 generates a curtailment signal which when received by WTGs 120 causes the WTGs to implement curtailment measures, such as, e.g., yawing or tilting the plane of rotation, varying the blade pitch, etc., further reducing the probability of an UpRR violation. This may be useful, for example, for re-enabling or maintaining power smoothing operations during periods of frequent excursions.
As described above, in addition to ramp control and smoothing operations, PMS 110 also provides the ability to capture curtailed wind power in order to increase operating efficiency and overall wind farm capacity. For example, during low demand periods (typically late at night and/or early in the morning), the utility may constrain the output of the wind turbine generators to balance the grid supply with demand. Depending on the value of the curtailment signal and the strength of the wind, the operating efficiency of the wind farm can be significantly reduced during curtailment periods. PMS 110 is operable to absorb the excess capacity without modifying any curtailment mechanisms that may already be in place.
For example, WTGs 120 and PMS 110 are each configured to detect when the curtailment signal value decreases below the wind farm's potential output. Responsive to the detection, WTGs 120 immediately adjust to reduce the net output of the wind farm to a value below or equal to the curtailment value. Once PMS 110 determines the net output of the wind farm is equal to the curtailment value, it begins to absorb power from the wind farm at a user programmable rate (e.g., 600 kW/min or 10 kW/sec) slightly reducing the total output of the wind farm. If additional wind energy is available, WTGs 120 increase net power output until the curtailment level is reached once again. During this time the power absorbed by PMS 110 remains constant. The process repeats as long as there is excess wind power to be gathered and the curtailment signal value is less than the wind farm's potential output (based on current wind speeds). If, during the curtailment period, the wind power suddenly decreases below the curtailment signal value, PMS 110 stops absorbing power and immediately begins supplying power to maintain a net output having a rate of change less than or equal to the maximum ramp rate (e.g., −ExcRR).
Each time the process is repeated, the amount of power absorbed by PMS 110 (PAbsorbed) increases and the excess amount of available wind power (PAvailable) decreases. The “potential wind power” (PPotential) is equal to the power that could be generated by the wind farm if there were no curtailment restrictions and no power was absorbed by PMS 110 . PLimit represents the curtailment signal value. Thus, PAvailable=PPotential−PLimi PAbsorbed. Once PAvailable is equal to zero, no additional power is available for PMS 110 to absorb. If PAvailable becomes less than zero, PMS 110 stops absorbing power and immediately begins supplying power to maintain a net output having a rate of change less than or equal to the maximum ramp rate.
User programmable system parameters set the percentage of the storage capacity to be dedicated to capture curtailed wind power during certain periods of the day, week, year, etc., and the percentage of the storage capacity to be dedicated for smoothing and excursion control. When the storage capacity allocated for curtailment is full, PMS 110 will continue smoothing and excursion control. PMS 110 will release the energy stored during curtailment at the first available opportunity at the maximum allowable rate. The opportunity to release energy to the grid when not in curtailment (i.e., PLimit=PPotential) is determined by comparing PPotential with the total capacity of the wind farm.
FIGS. 6 and 7 illustrate exemplary implementations power management systems 610 , 710 (e.g., PMS 110 described above) for providing excursion, smoothing, and curtailment control/operations for photovoltaic (PV) parks including PV panels 621 in PV array 620 and for wave power parks including power generators 721 in wave power array 720 , respectively.
In the description above, for the purposes of explanation, numerous specific details have been set forth in order to provide a thorough understanding of the embodiments of the invention. It will be apparent however, to one skilled in the art, that one or more other embodiments may be practiced without some of these specific details. The particular embodiments described are not provided to limit the invention but to illustrate embodiments of the invention. The scope of the invention is not to be determined by the specific examples provided above but only by the claims below. In other instances, well-known circuits, structures, devices, and operations have been shown in block diagram form or without detail in order to avoid obscuring the understanding of the description. Where considered appropriate, reference numerals or terminal portions of reference numerals have been repeated among the figures to indicate corresponding or analogous elements, which may optionally have similar characteristics.
Certain operations may be performed by hardware components, or may be embodied in machine-executable instructions, that may be used to cause, or at least result in, a circuit or hardware programmed with the instructions performing the operations. The circuit may include a general-purpose or special-purpose processor, or logic circuit, to name just a few examples. The operations may also optionally be performed by a combination of hardware and software.
One or more embodiments include an article of manufacture that includes a tangible machine-accessible and/or machine-readable medium having stored thereon instructions, that if executed by a machine (e.g., an execution unit) causes the machine to perform the operations described herein. The tangible medium may include one or more solid materials. The medium may include, a mechanism that provides, for example stores, information in a form that is accessible by the machine. For example, the medium may optionally include recordable mediums, such as, for example, floppy diskette, optical storage medium, optical disk, CD-ROM, magnetic disk, magneto-optical disk, read only memory (ROM), programmable ROM (PROM), erasable-and-programmable ROM (EPROM), electrically-erasable-and-programmable ROM (EEPROM), random access memory (RAM), static-RAM (SRAM), dynamic-RAM (DRAM), Flash memory, and combinations thereof. Still other embodiments pertain to a computer system, embedded system, or other electronic device having an execution unit configured to perform one or more of the operations disclosed herein.
A number of embodiments of the invention have been described. Nevertheless, it will be understood that various modifications may be made without departing from the spirit and scope of the invention. For example, solar and/or geothermal energy may be used instead of or in addition to wind energy to provide renewable energy. Further, the capacity, measurement resolution, response time, and limits described above are merely exemplar values. Accordingly, other embodiments are within the scope of the following claims. | A power delivery rate from a renewable power source to a load is managed by determining, by processing circuitry, a change in a power generation rate, determining, by the processing circuitry, whether the change in the power generation rate exceeds a limit, and then, adjusting, by control circuitry, a power transfer rate to or from a power storage device, such that the adjusting is sufficient to prevent the power delivery rate from exceeding the limit. | 8 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a semiconductor memory device and, in particular, to a cell plate line driver circuit which can implement a strong drive power and rapid operability required in case of designing a RAM having a material of large electrostatic capacity as a memory device and a circuit for transferring an output of the cell plate line driver circuit to a cell plate line without loss.
2. Related prior art
A driver for driving a word line for controlling an In/Out of information in a memory device of DRAM memory semiconductor which is presently commercially available requires only a potential higher than or equal to a certain level.
Therefore, the word line driver plays a role of making ON/OFF the potential higher than or equal to the certain level and comprises, as shown in FIG. 1 a level shifter section 10 for shifting a voltage level, a driver section 30 for driving the output voltage of the level shifter section 10 to a word line, and a control section 40 for controlling the operation of the driver section 30.
In operation of the word line driver constituted as described above, when a control signal C1 applied to the control section 40 is enabled with a value "High", it turns on a N-MOS transistor N31 of the driver section 30 via each inverter INV41, 42 in the control section.
on the other hand, the control signal C1 is input to the level shifter section 10 via a delay 50 having a predetermined delay time, and thereafter operates the level shifter so as to apply a high voltage Vpp to the driver section 30 via a PMOS transistor P11, and eventually this voltage is applied to the word line.
FIG. 2 shows a voltage variation of each line varying in a process in which the above described operation is performed, and it can be seem from the drawing that the word line W/L gradually increases in its voltage to Vpp.
The word line driver operating as described above has small electrostatic capacity of memory device presently manufactured with silicon, and therefore, the driving capability of the driver is not very important.
However, when using a material of large electrostatic capacity including a ferroelectric materials instead of silicon which is a memory device of DRAM, in case of using a conventionally used word line driver structure as they are to a cell plate line drive, various problems occur.
In case of using the ferroelectric materials as a memory device, a certain level is required to the cell plate line.
In case of using the material of large electrostatic capacity as a memory device, since the material itself has very large electrostatic capacity in comparison to the silicon, it requires a strong driving capability.
Therefore, to commercialize a RAM using such material as a memory device, the word line driver circuit presently used in DRAM can not be used and new type of circuit is required.
SUMMARY OF THE INVENTION
In consideration of conventional requirements described above, an object of the present invention is to provide a driver circuit which satisfies the requirements required by the cell plate line driver when using the material of large electrostatic capacity including the ferroelectric material and a decoder circuit conforming to the driver circuit.
Other object of the present invention is to provide a semiconductor memory device which uses the cell plate line driver as the word line driver.
The constitution of the present invention to accomplish the object described above has a cell plate line driver circuit comprising: a high voltage application section for applying a high voltage Vpp to said cell plated line; an internal voltage application section for applying an internal voltage Vint to said cell plate line; a voltage comparison section for comparing a reference cell plate line CPL-ref potential and a potential of an internal voltage and for outputing to said each voltage application section; and a control section for controlling the operation of said each section.
The constitution of the present invention to accomplish the object described above has a decoder circuit including a decoder section and a cell array cooperating with a cell plate line driver comprising: a selection section for selectively applying to a cell of which a word line is enabled a cell plate line voltage inputted from said cell plate line driver circuit; and an output section for inputting a signal CPL-ref to a voltage comparison section of said cell plate line driver if said cell plate line voltage applied through said selection section is shifted to said reference cell plate line CPL-ref voltage through a cell array; and wherein switching devices constituting said selection section and output section prevent loss of I/O signal by using CMOS transistors.
In addition, a semiconductor memory device to accomplish the object described above comprises:
(A) a cell plate line driver circuit using a plurality of potentials to stabilize a potential of a cell plate line CPL comprising: a high voltage application section for applying a high voltage Vpp to said cell plate line; an internal voltage application section for applying an internal voltage Vint to said cell plate line; a voltage comparison section for comparing a reference cell plate line CPL-ref potential and a potential of an internal voltage and for outputing to said each voltage application section; and a control section for controlling the operation of said each section; and
(B) a decoder circuit comprising: a selection section for selectively applying to a cell of which a word line is enabled a cell plate line voltage inputted from said cell plate line driver circuit; and an output section for inputting a signal CPL-ref to a voltage comparison section of said cell plate line driver if said cell plate line voltage applied through said selection section is shifted to said reference cell plate line CPL-ref voltage through a cell array.
BRIEF DESCRIPTION OF THE DRAWINGS
The above object and other advantages of the present invention will become more apparent by describing in detail the preferred embodiment of the present invention with reference to the attached drawings in which:
FIGS. 1 shows a word line driver circuit diagram of DRAM using the conventional silicon as a memory device;
FIGS. 2 shows a graph showing a voltage variation of each node at the time of operation of circuit of FIG. 1:
FIGS. 3 shows a cell plate line drive circuit diagram of RAM of the present invention using as a memory device a material of large electrostatic capacity;
FIGS. 4 shows a graph showing a voltage variation of each node at the time of operation of circuit of FIG. 3; and
FIGS. 5 shows a decoder circuit diagram using an output of the cell plate line driver according to the present invention.
Similar reference characters refer to similar parts in the several views of the drawings.
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described in detail with reference to the accompanying drawings.
The concept of the present invention is to use an electric source having two different potentials at the cell plate line driver stage to supply a certain potential to the cell plate line in short time and is to drive initially by connecting the electric source of high potential and to stabilize the potential of cell plate line by connecting the electric source of low potential if a certain level is reached, and the scheme of decoding the cell plate line is to transfer the output produced by the cell plate line driver stage to the cell plate line without loss by connecting a switch to a decoder.
A cell plate line driver circuit according to the present invention as shown in FIG. 3 comprises:
a high voltage application section 60 for applying a high voltage Vpp to said cell plate line;
an internal voltage application section 70 for applying an internal voltage Vint to said cell plate line;
a voltage comparison section 80 for comparing a reference cell plate line CPL-ref potential and a potential of an internal voltage and for outputing to said each voltage application section; and
a control section 90 for controlling the operation of said each section.
The high voltage application section 60 comprises:
a plurality of inverting devices INV61 and INV62 for inverting the signal outputted from said voltage comparison section 80;
a PMOS transistor P61 for outputting the high voltage Vpp to said cell plate line CPL by being turned on/off by the signal outputted from said inverting device INV62; and
a N-MOS transistor N61 connected to one terminal of said P-MOS transistor P61 and turned on/off according to the signal outputted from said control section 90.
The internal voltage application section 70 comprises:
a NOR-gate NOR71 for operating a signal outputted from said inverting device INV61 in said high voltage application section 60 and a signal outputted from said control section 90;
an inverting device INV71 for inverting a signal outputted from said NOR-gate NOR71;
a PMOS transistor P71 for outputting an internal voltage Vint to said cell plate line CPL by being turned on/off by the signal outputted from said inverting device INV71.
The voltage comparison section 80 comprises: a differential amplifier 81 for receiving and differentially amplifying a reference cell plate line voltage CPL-ref and said internal voltage. applying the high voltage Vpp to CPL if said CPL-ref potential is lower than said internal voltage Vint and applying said internal voltage Vint to CPL if said CPL-ref potential is higher than said internal voltage Vint; and a plurality of PMOS transistors P81 and P82 and N-MOS transistors N81 and N82.
The control section 90 comprises a plurality of inverting device INV91 to INV94 for receiving and inverting a control signal C2 and NMOS transistors N91 and N92.
The operation of the cell plate line driver circuit implemented as described above will be explained. If the control signal C2 is enabled to a value "High" and input, the voltage comparison section 80 starts to operate and if a potential CPL-ref among signals inputted to the differential amplifier 81 is lower than a potential Vint, the voltage comparison section 80 outputs a "Low" value.
This Low value turn on the P-MOS transistor P61 via each inverting device INV61 and INV62 of the high voltage output section 60 so as to apply the high voltage to CPL.
At the same time, a "High" signal outputted from the inverting device INV61 is inputted to a terminal of NOR-gate NOR71 of internal voltage output section 70, and a "Low" value generated by inverting the control signal C2 by the inverter INV94 is inputted to the other terminal of the NOR-gate NOR71.
Therefore, "Low" value is output form the NOR-gate NOR71, and the P-MOS transistor P71 is turned off so as to prevent the internal voltage from being outputted to CPL.
On the other hand, if the potential CPL-ref at the differential amplifier 81 is higher than Vint, "High" value is outputted and this value turns off the P-MOS transistor P61 of high voltage output section 61 so as to prevent the high voltage from being outputted and turns on the P-MOS transistor P71 of internal voltage output section 70 so as to apply Vint to CPL.
At this time, Vpp is the electric source having higher potential than that actually supplied to CPL, and Vint is the electric source having same potential as that supplied to W/L.
CPL-ref being compared with Vint is the voltage value (refer to FIG. 5) of the porting to which the weakest electric source is supplied in case where the potential is connected to the cell plate line.
FIG. 4 shows a voltage variation of each line varying in the process in which the operation described above is performed. As shown in the drawing, the cell plate line CPL is fast driven up to Vint potential, and does not go up to Vpp potential but maintain Vint potential. In the drawing, control-Vpp is the gate stage b of the high voltage output section 60, and maintains the "Low" state until the cell plate line reaches Vint potential so as to supply Vpp to the cell plate line.
In the drawings, it can be seen that control-Vint is a gate stage c of the Vint application section 70 and is enabled to "Low" state to maintain the cell plate line to Vint potential after the Vpp application section 60 is turned off.
FIG. 5 shows a circuit which shows a condition in which CPL outputted from FIG. 4 is applied to a cell array and which shows a decoder section and a cell array.
FIG. 5 comprises:
a decoder section 100 for receiving and decoding a row address X-address;
a selection section 110 for enabling the word line by inverting a signal outputted from said decoder section 100 and, at the same time, for applying to a cell of which a word line is enabled the CPL applied from said cell plate line driver;
a cell array 120; and
an output section 130 for outputting CPL-ref which is CPL voltage having passed through said cell array 120.
At this time, all of the switching devices used in the selection section 110 and output section 130 use CMOS transistors so as to transfer the output generated at the cell plate line driver to the cell plate line without loss.
In operation of the cell array constructed as described above, if each of X-addresses X0 and X1, for example, is inputted as "Low" value, the uppermost decoder is selected and the output of this decoder becomes "Low" value.
This signal, in turn, becomes "High" through the inverting element of the selection section 110 so as to select the word line, and at the same time, the switch is turned on so that CPL voltage is applied to the cell.
Then, the CPL voltage is lowered down to some extent by resistors when the CPL voltage goes through the word line, thereafter outputted through the output section 130 as CPL-ref voltage, and inputted to the voltage comparison section 80 of FIG. 3.
At this time, the CPL-ref voltage is the voltage of presently enabled line among the lines which have been decoded to give outputs.
Although the cell array circuit of the present invention acting as described above is implemented to decode four cell plate lines, it is of course understood that the number of the lines can be extended to 8, 16 and even more.
As described above in detail, the present invention has advantages of stabilizing the potentia of the cell plate line by using two kinds of potentials for the cell plate line driver used in case of commercializing the RAM, which uses as the memory device the material having large electrostatic capacity including the ferroelectric materials, instead of the RAM which presently uses silicon as the memory device.
In addition, the decoder circuit cooperating with the cell plate driver circuit cooperating with the cell plate driver circuit eliminates the loss of signal input/output by using the CMOS transistor as the switching device.
The present invention has been described with reference to a particular embodiment in connection with a particular application. Those having ordinary skill in the art and access to the teachings of the present invention will recognize additional modifications and applications within the scope thereof.
It is therefore intended by the appended claims to cover any and all such applications, modifications, and embodiments within the scope of the present invention | The present invention relates to semiconductor memory device and more particularly, to a technique for stabilizing the potential of the cell plate line by using two kinds of potentials for the cell plate line driver to implement the powerful driving force and rapid operability required in case of designing the RAM using as the memory device the material having large electrostatic capacity, and for preventing the loss of I/O by using CMOS transistors in the decoder circuit which receives the cell plate line voltage by cooperating with the cell plate line driver circuit and feeds back the cell plate line voltage. | 6 |
BACKGROUND OF THE INVENTION
Field of the Invention
This invention relates to techniques for improving the efficiency of turbine engines and reduction of noxious components in the turbine exhaust gases. More particularly, the invention relates to a new and improved injector for turbine engines, which injector is characterized in a preferred embodiment by a shaped injector core fitted with an eccentric spinner inlet nozzle communicating with a cylindrical, annular spinner chamber, and a preheater or evaporator for preheating fuel and injecting the vaporized fuel at a selected temperature into the fuel spinner chamber through the eccentrically-positioned fuel spinner nozzle or opening, to effect a spinning fuel sequence around a fuel guidance pin extending through the fuel spinner chamber. Compressed air from the turbine compressors flows through the primary nozzle of an air guidance nozzle enclosing each injector core, into a shaped secondary nozzle and mixes with the spinning fuel in a flow focus zone at a selected mixing air flow angle to facilitate thorough and homogeneous mixing of the fuel as it is channeled into the annular turbine combustor. The unique spinning component applied to the preheated, vaporized fuel by the several injectors and the manner of introducing air into the spinning fuel from the respective secondary nozzles of the air guidance nozzles effects surprisingly good air-fuel mixing and facilitates excellent engine operating efficiency and reduction of undesirable "NOX" emissions in the turbine exhaust gases.
One of the problems which is arising in ever-increasing significance is that of noxious, air-polluting components in the exhaust gases of turbine engines, including jet airplane engines and such equipment as stationary engines, typically turbine-operated generators, pumps and refrigeration turbine engines, as well as other engines and systems utilizing fuel injecting equipment. Solutions to this problem have included both wet and dry "NOX" control techniques which are well known to those skilled in the art, for the purpose of lowering undesirable turbine exhaust gas emissions. These emissions are hereinafter collectively referred to as NOX and include such ingredients such as carbon monoxide, nitrogen dioxide and the like, and in light of current pollution control standards, new and improved techniques for reducing these undesirable NOX emissions from turbine and other system exhaust gases is necessary. The conventional use of wet NOX and dry NOX techniques for achieving this result require heavier and more complex turbine equipment and are therefore counterproductive in many installations, including aircraft, as well as industrial and other applications.
Accordingly, it is an object of this invention to provide a new and improved injector for turbine engines of various design, which injector not only increases the efficiency of the turbine engine with no increase in weight or complexity, but also reduces the emission of noxious, air-polluting components (NOX) from the turbine exhaust.
Another object of this invention is to provide a new and improved injector for turbine engines and other engines and systems utilizing fuel injection equipment of various design, which injector is characterized by an injector core shaped to define an internal, curved, annular fuel spinner chamber having a centrally-projecting fuel guidance pin to facilitate spinning of fuel vapor introduced into the fuel spinner from an evaporator through an eccentrically-positioned spinner inlet, such that a spiral of spinning, preheated and vaporized fuel is created in the fuel spinner chamber and mixes with incoming compressed air from the turbine compressors or alternative air source at a selected mixing angle to effect a surprisingly complete and homogeneous mixture of air and fuel channeled to the turbine or engine combustor system.
Still another object of this invention is to provide new and improved injectors for turbine engines, a selected design number of which injectors can be retrofitted to the annular combustion of existing turbine engines, as well as provided on new turbine engines and each injector including an air guidance nozzle enclosing a tapered injector core having an internal cylindrical, annular fuel spinner chamber defined around an outwardly-projecting fuel guidance pin having an enlarged end or tip, wherein preheated, vaporized fuel from a heat exchanger enters the fuel spinner chamber through an eccentrically-oriented spinner inlet to facilitate a spiral rotation of fuel in the annular fuel spinner chamber around the fuel guidance pin and from the fuel spinner chamber, guided by the fuel guidance pin tip, into an inwardly-directed, continuous, compressed air stream flowing through the corresponding air guidance nozzle, to create a significantly homogeneous, stoichiometric mixture of fuel and air prior to entrance of the combustible mixture into the annular turbine combustor.
SUMMARY OF THE INVENTION
These and other objects of the invention are provided in new and improved injectors for mounting in radially spaced relationship with respect to each other on the annular combustors of turbine engines, each of which injectors is characterized in a preferred embodiment by a shaped metal, ceramic or ceramic-coated injector core located in an air guidance nozzle, wherein compressed air from the turbine compressors is caused to flow between each injector core and the corresponding air guidance nozzle in inwardly-directed relationship to mix at a selected mixing angle with vaporized fuel introduced into a cylindrical fuel spinner chamber shaped in the injector core, through an eccentrically-located spinner inlet. The fuel is preheated as a vapor or vaporized in an evaporator or heat exchanger and is thus introduced along a selected chord of the circle defining the fuel spinner chamber and against the curved cylindrical wall of the fuel spinner chamber perpendicular to the longitudinal axis of the injector core, to impart a spinning and spiralling rotation of the fuel around a centrally-projecting fuel guidance pin that extends through the fuel spinner chamber, to mix with the air and create a significantly homogeneous, stoichiometric mixture of fuel and air, which is then delivered by the air stream to the annular combustor. This homogeneous mixing of preheated and vaporized fuel and air by the spiralling movement of the fuel into the air stream both increases the efficiency of the turbine and reduces the emission of NOX in the turbine exhaust gases.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be better understood by reference to the accompanying drawings, wherein:
FIG. 1 is a perspective view, partially in section, of a typical conventional gas turbine engine;
FIG. 2 is a sectional view of the gas turbine engine illustrated in FIG. 1, illustrating an injector of this invention installed therein;
FIG. 3 is a sectional, partially schematic view of a preferred embodiment of the injector of this invention; and
FIG. 4 is a sectional view, taken along line 4--4 of the air guidance nozzle and injector core elements of the fuel injector illustrated in FIG. 3.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring initially to FIGS. 1 and 2 of the drawings, a conventional turbine engine which is typical of the turbine engines in which the injectors of this invention may be mounted, is illustrated by reference numeral 1. The turbine engine 1 is characterized by an accessory drive assembly 2, which may be connected to various equipment such as a compressor, propeller or the like, for doing useful work. An air inlet assembly 3 is illustrated at the front of the turbine engine 1 and facilitates a flow of ambient air 4 into the turbine engine 1. The air 4 passes through a compressor rotor 5, which is fitted with multiple, radially-extending rotor blades 5a, located in a compressor case 6. A compressor variable vane assembly 7 extends from the compressor case 6 radially outwardly of the compressor rotor 5, as illustrated. A compressor diffuser 8 is provided on the inboard end of the compressor case 6 and a gas fuel manifold 9 encircles the combustor housing 35a, which encloses the annular combustor 35. Fuel lines 9a serve to channel fuel from the circular gas fuel manifold 9 to the conventional fuel injector 27, illustrated in FIG. 1, and identified by reference numeral 10 in FIG. 2, as a fuel injector of this invention. A bleed air valve 36, nozzle case 37, gas producer turbine rotor 38, power turbine rotor 39, output drive shaft assembly 40, turbine exhaust diffuser 41 and exhaust collector 42 complete the major components of the conventional, illustrative turbine engine 1 illustrated in FIGS. 1 and 2 of the drawings.
Each one of the multiple fuel injectors 10 of this invention is more particularly illustrated in FIGS. 2-4 of the drawings and includes a cylindrical air-guidance nozzle 11, illustrated in FIGS. 3 and 4, having a cylindrical nozzle housing 17 which is symmetrical about a longitudinal axis 10a and terminates in a nozzle bevel 11a. The air-guidance nozzle 11 includes a primary nozzle chamber 12, which receives compressed air from the compressor rotor 5 illustrated in FIGS. 1 and 2, and a secondary nozzle chamber 13, which channels and directs the compressed air from the primary nozzle chamber 12 into an annular, converging stream. The compressed air flow from the compressor rotor 5 is indicated by the arrows 14 in the primary nozzle chamber 12 and by the arrows 23, as a mixing air flow, in the secondary nozzle chamber 13, as shown in FIG. 3. An injector core 15, having a cylindrical core wall 18, is disposed inside each cylindrical air guidance nozzle 11 and is also symmetrical about each longitudinal axis 10a, to define the secondary nozzle chamber 13. That portion of the injector core 15 which faces the incoming compressed air flow 14 is most preferably characterized by a core taper 16, shaped to channel the compressed air flow 14 around the injector core 15 and into the inwardly-directed secondary nozzle chamber 13 to define the mixing air flow 23, as illustrated in FIG. 3. A wall bevel 19 encircles the opposite end of the injector core 15 from the core taper 16 and parallels the nozzle bevel 11a of the air guidance nozzle 11 to further define the secondary nozzle 13. An internal, cylindrical, annular fuel spinner chamber 20 is provided in the injector core 15 opposite the core taper 16 and receives an outwardly-extending, centrally-positioned fuel guidance pin 22, having an enlarged, flared end 22a, which is also symmetrical about the longitudinal axis 10a of each fuel injector 10. As further illustrated in FIGS. 3 and 4, a spinner inlet 21 is eccentrically provided in the curved wall of the cylindrical, annular injector core 15 and communicates with a fuel flow line 32, extending from an evaporator 28, hereinafter further described. Accordingly, fuel 32a which is injected into the annular space between the circular fuel spinner chamber 20 and the fuel guidance pin 22 from the eccentrically-oriented spinner inlet 21 is injected along a chord of the circle defining the spinner chamber 20, directly against the curved wall of the cylindrical fuel spinner chamber 20, thereby imparting a spinning component to the entering fuel, which has been preheated by heat exchange in the evaporator 28, as further hereinafter described. The spinning, vaporized and preheated fuel is identified by reference numeral 24 and the spinning fuel 24 spirals from the point of impingement in the spinner chamber 20, annularly around the fuel guidance pin 22 as illustrated in FIG. 4, to diffuse in the converging mixing air flow 23 flowing from the secondary nozzle chamber 13 at the wall bevel 19 of the core wall 18, in a flow focus zone 25, as illustrated in FIG. 3 and as further hereinafter described.
Referring again to FIGS. 3 and 4 of the drawings, the evaporator 28 is characterized by a first pass chamber 30 and a second pass chamber 30a, which direct the fuel 32a from the fuel inlet 31 through the evaporator 28. Application of external heat 29 from the combustor 35 of the turbine engine 1 vaporizes the incoming fuel 32a if it is introduced as a liquid and preheats the vaporized fuel 32a to the point of entry into the cylindrical, annular fuel spinner chamber 20, through the spinner inlet 21. Accordingly, the fuel 32a is preheated and vaporized when it exits the spinner inlet 21 and begins its spiralling annular flow as the spinning fuel 24 around the fuel guidance pin 22 and flared end 22a, into the mixing air flow 23, as heretofore described and illustrated.
In operation, liquid or gaseous fuel 32a from a suitable storage tank (not illustrated) is introduced into the gas fuel manifold 9 illustrated in FIGS. 1 and 2 and is continuously pumped from the gas fuel manifold 9 through the fuel lines 9a and into the fuel inlet 31 of the evaporator 28, illustrated in FIG. 3. Typical fuels which may be handled by the fuel injector 10 of this invention include methane, butane, propane, kerosene, alcohol, acetone, hydrogen and fluidized charcoal dust, in nonexclusive particular. If the fuel 32a is liquid when it enters the fuel inlet 31, it is quickly vaporized by application of the external heat 29 to the first pass chamber 30 and second pass chamber 30a. If gaseous fuel 32a is introduced into the fuel inlet 31, it is preheated to the desired injection temperature and in both cases, the fuel 32a exits as a preheated vapor at the spinner inlet 21 into the cylindrical, annular fuel spinner chamber 20. As illustrated in FIG. 4, the vaporized fuel 32a is directed longitudinally normal to the longitudinal axis 10a, along a chord of the circle defined by the circular fuel spinner chamber 20, against the curved wall of the fuel spinner chamber 20 and a spiralling spin having a fuel spinning velocity 24a, is thus imparted to the vaporized and preheated spinning fuel 24 as it rotates in the annular fuel spinner chamber 20, around the centrally-located and extending fuel guidance pin 22. The fuel spinning velocity 24a is a function of the speed of rotation of the vaporized fuel 32a and the diameter of the fuel spinner chamber 20. Accordingly, this spinning fuel 24 continuously spins toward the compressed mixing air flow 23, which continuously flows through the secondary nozzle chamber 13 at a selected mixing air flow angle 23a, measured with respect to the longitudinal axis 10a and is directed inwardly by the wall bevel 19 of the injector core 15 and the nozzle bevel 11a of the air guidance nozzle 11. The mixing air flow angle 23 typically ranges from 0 degrees to about 90 degrees, depending upon application. The enlarged, flared tip or end 22a of the fuel guidance pin 22 directs the spinning fuel 24 into the mixing air flow 23 at a desired angle, preferably about 80 to 90 degrees, in a flow focus zone 25 and the spinning fuel 24 is quickly and efficiently diffused into the mixing air flow 23 to create an extremely homogeneous, highly combustible stoichiometric air/fuel mixture 26 in the flow focus zone 25, carried into the combustor inlet 33 of the combustor 35 by an excess of air in the mixing air flow 23, where it is ignited in conventional fashion. Accordingly, the rotational spin imparted to the preheated, vaporized, spinning fuel 24, coupled with the inwardly-directed compressed mixing air flow 23 to thoroughly and homogeneously mix the fuel and air, effects combustion which facilitates optimum turbine engine operating efficiency and minimum discharge of NOX in the exhaust gases 43 emitted from the exhaust collector 42 of the turbine engine 1. This elevation of turbine engine efficiency and reduction of NOX is therefore effected by more efficient mixing and burning of the fuel with an excess of air to produce thorough, stoichiometric burning and minimum emission of undesirable exhaust components such as carbon monoxide.
It will be appreciated by those skilled in the art that the evaporator 28 is illustrated in FIG. 3 as a double-pass heat exchanger for purposes of illustration only. Accordingly, a multiple-pass or even a single-pass heat exchanger may be used to characterize the evaporator 28, according to the knowledge of those skilled in the art, depending upon the temperature and character of the incoming fuel 32a entering the fuel inlet 31. For example, if the fuel 32a entering the fuel inlet 31 is liquid at a low temperature, appropriate external heat 29 will be applied to the evaporator 28 and the evaporator 28 must be designed with the appropriate number of pass chambers to effectuate entry of an appropriately evaporated and preheated fuel 32a at the spinner inlet 21 of the injector core 15. Under circumstances where the incoming fuel 32a is already vaporized and is at a higher temperature, minimum application of external heat 29 and a single pass such as a first pass chamber 30 only, may be necessary in the evaporator 28 to effect the desired injection temperature at the spinner inlet 21. Furthermore, it will be further understood that the size of the nozzle housing 17 and internal injector core 15, including the secondary nozzle chamber 13, as well as the dimensions of the fuel spinner chamber 20 and fuel guidance spin 22 and flared end 23 and the other components of the fuel injector 10, may be varied and sized according to the dimensions of the turbine engine 1 in which the fuel injectors 10 are installed and used. Moreover, a selected number, typically 9 or 10, of fuel injectors 10 may be installed in annular, circumferentially-spaced fashion around the annular combustor 35, according to design requirements for the respective turbine engine 1. Also, various types of pumps, accessory equipment and the like, may be used in connection with the fuel injectors 10 to supply either liquid or gaseous fuel to the evaporator 28, according to the knowledge of those skilled in the art. It will be further appreciated that the fuel injectors 10 may be retrofitted to existing turbine engines and installed in new turbine engines, as desired.
The fuel injectors 10 of this invention may also be installed on burner systems and engines of non-turbine design. Since the application of one or more fuel injectors 10 operates to more efficiently disperse preheated, vaporized fuel into a directionally-controlled air stream, this application can be made to internal combustion engines, including reciprocating and rotary engines, as well as boiler systems and other systems requiring injection of fuel into a combustor or combustion chamber of various design and description. In any such engine or burner system, regardless of size, complexity or design, one or more of the injector cores and air guidance nozzles illustrated in FIGS. 2-4 may be mounted in the engine or burner at or near the combustion chamber. And a blower, or other air delivery system may be used to move air around the injector core through the air guidance nozzle, or, in the alternative, around the injector core in the angular relationship described above with respect to the longitudinal axis of the injector core, to create the desired stoichiometric mix of air and fuel for combustion and achieve the intents and purposes of the invention.
While the preferred embodiments of the invention have been described above, it will be recognized and understood that various modifications may be made in the invention and the appended claims are intended to cover all such modifications which may fall within the spirit and scope of the invention. | An injector for turbine engines which includes a shaped injector core fitted with an eccentric spinner inlet communicating with a cylindrical, annular fuel spinner chamber and a preheater or evaporator for preheating and vaporizing fuel, wherein the vaporized fuel is eccentrically injected into the fuel spinner chamber to effect a spinning fuel sequence around a fuel guidance pin extending through the center of the fuel spinner chamber. Compressed air from the turbine compressors flows through the primary nozzle of an air guidance nozzle surrounding the injector core into a shaped secondary nozzle, where the air mixes with the spinning fuel at a selected air flow angle to facilitate thorough mixing of the fuel and air as the combustible mixture is channeled into the annular turbine combustor. The unique spinning component applied to the preheated, vaporized fuel and manner of introducing the compressed air into the spinning fuel using multiple, spaced injectors and corresponding air guidance nozzles effects exceptionally good air-fuel mixing and facilitates increased turbine operating efficiency and reduction of NOX emissions in the turbine exhaust gases. | 5 |
BACKGROUND OF THE INVENTION
The present invention relates to a driving control method of a glow plug that is mainly used to aid the start of a diesel engine, and in particular, to improvement of the stability and reliability of temperature control.
In the vehicle using a diesel engine, a glow plug has been used for aiding the starting, and the stability and reliability of the temperature control have a large influence on the quality of combustion, in other words, the quality of the engine operation. Accordingly, it is an important issue how the stable power control can be realized.
Therefore, for power control of the glow plug, various control methods have been proposed and put into practical use from various points of view (for example, refer to JP-A-2009-168319 and WO2010/001888 and the like).
Incidentally, the actual temperature characteristics (heating characteristics) of the glow plug, that is, the heating temperature when a certain voltage is applied varies relatively in many cases depending on each glow plug even if a so-called production lot is the same. This is even more so if the production lot is different.
On the other hand, as power control of the glow plug in a vehicle, for example, a method is generally adopted frequently in which an appropriate driving voltage according to various kinds of engine speeds and the load conditions of the engine is set in advance on the basis of the conduction characteristics of the standard glow plug and is stored in an electronic control unit, which controls the operation of the vehicle, the driving voltage is read at any time during the actual operation of the vehicle, and the glow plug is driven by the read voltage.
However, as described above, when the variation in the temperature characteristics of the glow plug mounted in the vehicle appears great, a difference occurs between the target temperature and the actual temperature of the glow plug for the voltage applied as described above. This may cause a problem in that it becomes difficult to ensure an appropriate combustion state.
SUMMARY OF THE INVENTION
The invention has been made in view of the above-described situation, and it is an object of the invention to provide a glow plug driving control method and a glow plug driving control device by which the accuracy in controlling the heating temperature of a glow plug is improved and the stability and reliability of the control operation are improved.
According to a first aspect of the invention, there is provided a glow plug driving control method for controlling power application to a glow plug. The glow plug driving control method includes correcting a voltage applied to the glow plug, which is set according to operating conditions of an engine, using a correction coefficient, which is set in advance according to temperature characteristics of the glow plug, and applying the corrected voltage to the glow plug to perform driving control.
According to a second aspect of the invention, there is provided a glow plug driving control device including: an electronic control unit that performs driving control of a glow plug; and a power circuit that performs power application to the glow plug according to the glow plug driving control performed by the electronic control unit. The electronic control unit is configured such that a standard applied voltage for the glow plug is set according to operating conditions of an engine, and is configured to correct the standard applied voltage using a correction coefficient set in advance according to a temperature classification of a mounted glow plug and to apply the corrected voltage to the glow plug to perform driving control.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram showing an example of the configuration of a glow plug driving control device to which a glow plug driving control method according to an embodiment of the invention is applied;
FIG. 2 is a subroutine flowchart showing the procedure of glow plug driving control according to the embodiment of the invention performed by an electronic control unit that forms the glow plug driving control device shown in FIG. 1 ;
FIG. 3 is a schematic diagram that schematically shows an example of the normal distribution of variations in the heating temperature of a glow plug used in the glow plug driving control device shown in FIG. 1 ; and
FIG. 4 is a schematic diagram that schematically shows an example of the correction coefficient map stored in the electronic control unit that forms the glow plug driving control device shown in FIG. 1 .
DETAILED DESCRIPTION
Hereinafter, an embodiment of the invention will be described with reference to FIGS. 1 to 4 .
It will be noted that the members and arrangements described below are not intended to limit the present invention and can be variously modified within the scope of the gist of the present invention.
First, an example of the configuration of a glow plug driving control device to which a glow plug driving control method according to the embodiment of the invention is applied will be described with reference to FIG. 1 .
A glow plug driving device according to the embodiment of the invention is configured so as to be largely divided into an electronic control unit (in FIG. 1 , denoted as an “ECU”) 101 and a power circuit (in FIG. 1 , denoted as a “DRV”) 102 .
For example, the electronic control unit 101 includes a microcomputer (not shown) as a main component, which has a known configuration, and a storage element (not shown), such as a RAM or a ROM, and also includes an input/output interface circuit (not shown) for transmission and reception of a signal to and from an external circuit. The electronic control unit 101 performs engine control, fuel injection control, and the like of the vehicle and performs glow plug driving control processing to be described later.
The power circuit 102 has a known configuration for performing power application to a plurality of glow plugs 50 - 1 to 50 -n according to the glow plug driving control processing executed by the electronic control unit 101 .
The glow plugs 50 - 1 to 50 -n are provided corresponding to the number of cylinders of the engine (not shown), and one end of a heating element provided thereinside is connected to the output end of the power circuit 102 and the other end side of the heating element (not shown) is connected to the ground (vehicle body ground).
Next, the outline of a glow plug driving control method according to the embodiment of the invention will be described.
First, basic driving control of the glow plugs 50 - 1 to 50 -n that has been conventionally performed will be described.
The voltage applied when driving the glow plugs 50 - 1 to 50 -n is basically set to an appropriate value according to the operating conditions of the engine.
Here, the operating conditions of the engine are the concept indicating in which state the engine is, and includes both the conditions before the start of the engine and the conditions after the start of the engine.
First, before the start of the engine, a predetermined specified value as start mode according to the vehicle type or the engine type is used as the voltage applied to the glow plugs 50 - 1 to 50 -n.
On the other hand, after starting the engine, an appropriate value according to the engine speed Ne and the load conditions of the engine is set as an applied voltage. That is, for various combinations of the engine speed Ne and the load conditions of the engine, the relationship with a voltage (hereinafter, referred to as a “standard applied voltage” for convenience of explanation) to be applied when driving a glow plug having standard temperature characteristics (heating characteristics) is calculated as a map on the basis of test or simulation results, and is stored in advance in an appropriate storage region of the electronic control unit 101 . Then, an appropriate applied voltage is read from the map using the engine speed Ne and the load conditions of the engine when driving the glow plugs 50 - 1 to 50 -n as parameters, and the read applied voltage is applied to the glow plugs 50 - 1 to 50 -n. This is a conventional glow plug driving method.
In contrast, the glow plug driving control method according to the embodiment of the invention has been made in view of the fact that the standard applied voltage set on the basis of the standard glow plug is not necessarily a voltage value suitable for obtaining the desired temperature in the conventional driving control method described above.
That is, the glow plug driving control method according to the embodiment of the invention has been made taking into consideration that a certain amount of variation is inevitable to arise in the temperature characteristics of the glow plug during mass production.
Therefore, in the embodiment of the invention, when a glow plug mounted in a certain vehicle is determined, temperature characteristics are first measured for all glow plugs determined to be used, the glow plugs are classified according to the difference of the acquired temperature characteristics, a correction coefficient for correcting the standard applied voltage set on the basis of the standard glow plug is set for each classification, and the correction coefficient for each classification of the glow plug is stored in the electronic control unit 101 .
On the other hand, in the step where a glow plug used for each vehicle is specifically specified, a specific code indicating to which classification the glow plug belongs is input to the electronic control unit 101 , and the electronic control unit 101 recognizes to which classification the connected glow plugs 50 - 1 to 50 -n belong.
Then, when driving the glow plugs 50 - 1 to 50 -n, a correction coefficient corresponding to the glow plugs 50 - 1 to 50 -n is read from the storage region of the electronic control unit 101 , the standard applied voltage is corrected using the read correction coefficient, and the glow plugs 50 - 1 to 50 -n are driven with the corrected applied voltage (corrected applied voltage).
Hereinafter, the procedure of determining a correction coefficient will be specifically described.
First, FIG. 3 shows a schematic diagram, which schematically shows an example of the normal distribution of variations in the heating temperature of a glow plug. Hereinafter, explanation will be given with reference to FIG. 3 . In addition, in FIG. 3 , the vertical axis indicates the number of glow plugs.
As shown in FIG. 3 , assuming that the heating temperature when a voltage is applied in a specified condition is acquired by measurement for a plurality of glow plugs to be used, classification of the acquired heating temperature is performed according to the predetermined temperature classification criterion.
Here, the predetermined temperature classification criterion is a criterion for classifying the above-described glow plugs, for which heating temperature has been measured, into several temperature ranges.
In the example shown in FIG. 3 , for example, the glow plugs are classified into three ranges of a range of ±α around 1200° C. as a central value, a range equal to or higher than 1200° C.−β and lower than 1200° C.−α, and a range higher than 1200° C.+α and equal to or lower than 1200° C.+β. For convenience of explanation, a range where the temperature is equal to or higher than 1200° C.−β and lower than 1200° C.−α is referred to as a first classification (in FIG. 3 , denoted as “A”), a range of the temperature of 1200° C.±α is referred to as a second classification (in FIG. 3 , denoted as “B”), and a range where the temperature is higher than 1200° C.+α and equal to or lower than 1200° C.+β is referred to as a third classification (in FIG. 3 , denoted as “C”).
In addition, the magnitudes of α and β should be separately determined in consideration of the specific conditions, such as the specific conditions of each vehicle or the characteristics of each glow plug used.
In addition, although there are three classifications of A, B, and C in the classification example described above, the invention does not need to be limited to the three classifications, and the number of classifications can be appropriately set.
In addition, when glow plugs are classified as described above, upon identification of each piece of data, it is preferable to distinguish each piece of data by attaching the integer for classifying each piece of data, in ascending order from 1, after the above-described letters A, B, and C to distinguish the classification to which each piece of data belongs. Specifically, for example, these are A01, A02, B01, B02, . . . .
Here, for convenience of explanation, these A01, A02, B01, B02, . . . are referred to as “group codes”. In addition, reference signs A, B, and C when the above-described integer (01, 02, . . .) for identifying each piece of data is omitted are also referred to as “group codes” in the following explanation.
Then, a correction coefficient is set for each classification.
In the example shown in FIG. 3 , a correction coefficient is calculated for the first classification (in FIG. 3 , denoted as “A”) and the third classification (in FIG. 3 , denoted as “C”). That is, for the temperature median in each classification, a voltage correction value for obtaining the desired temperature can be calculated on the basis of test or simulation results.
On the other hand, for the second classification (in FIG. 3 , denoted as “B”), the correction coefficient is set to “1” in this example since the temperature is in a desired temperature range.
The correction coefficient for each classification calculated as described above is stored in the electronic control unit 101 as a correction coefficient map indicating the correspondence of a group code and a correction coefficient corresponding to the group code, for example, as shown in FIG. 4 . In addition, in FIG. 4 , it is assumed that Ka means a correction coefficient of a glow plug having a group code A, Kb means a correction coefficient of a glow plug having a group code B, and Kc means a correction coefficient of a glow plug having a group code C. In addition, in the example shown in FIG. 3 , Kb=1.
Next, the procedure of the glow plug driving control processing according to the embodiment of the invention executed by the electronic control unit 101 will be described with reference to a subroutine flowchart shown in FIG. 2 .
First, the glow plug driving control processing according to the embodiment of the invention is largely divided into processing executed only once when a glow plug driving control device is first started or when the glow plug driving control device performs driving first after the replacement of the glow plugs 50 - 1 to 50 - 1 (hereinafter, referred to as “initial processing” for convenience of explanation) and processing executed at any time when driving the glow plugs 50 - 1 to 50 - 1 (hereinafter, referred to as “repetitive processing” for convenience of explanation). FIG. 2(A) shows a subroutine flowchart showing the procedure of initial processing, and FIG. 2(B) shows a subroutine flowchart showing the procedure of repetitive processing.
First, the initial processing will be described with reference to the subroutine flowchart shown in FIG. 2(A) .
When the processing is started by the electronic control unit 101 , group (Gr) codes of the glow plugs 50 - 1 to 50 -n stored in advance in the appropriate storage region of the electronic control unit 101 are first read (refer to step S 102 in FIG. 2(A) ).
Then, correction coefficients corresponding to the read group codes are read from the correction coefficient map (refer to FIG. 4 ) stored in the electronic control unit 101 in advance as described above, and are stored in the appropriate storage region for arithmetic processing in order to be used in the calculation of a corrected applied voltage to be described later (refer to step S 104 in FIG. 2(A) ).
Since a correction coefficient that has been read once may be used unless the glow plugs 50 - 1 to 50 -n are replaced, a series of processes shown in FIG. 2(A) may be executed once when the operation is first started as a device as described above.
Next, the procedure of the repetitive processing will be described with reference to FIG. 2(B) .
When the processing is started by the electronic control unit 101 , a standard applied voltage is determined first (refer to step S 202 in FIG. 2(B) ). As the standard applied voltage, as described above, an appropriate value is set according to the operating conditions of the engine. That is, before the start of the engine, a predetermined specified value is used. Meanwhile, after the start of the engine, an appropriate value according to the engine speed Ne and the load conditions of the engine during the execution of this step is determined using a predetermined calculation expression or a map stored in advance in the appropriate storage region of the electronic control unit 101 .
In addition, since the engine speed and the load conditions of the engine are data acquired in the engine control processing executed in the same manner as in the related art by the electronic control unit 101 , it is sufficient to use the data, and it is not necessary to calculate the engine speed and the load conditions of the engine separately for the series of processes.
Then, on the basis of the previous correction coefficient and the above-described standard applied voltage Vdrv, an actual corrected applied voltage Vcorr applied to the glow plugs 50 - 1 to 50 -n is calculated (refer to step S 204 in FIG. 2(B) ).
That is, the corrected applied voltage Vcorr is calculated as Vcorr=K Vdrv. Here, K is a correction coefficient. If the glow plugs 50 - 1 to 50 -n belong to the first classification as shown in a previous example in FIG. 4 , the value is Ka.
After the corrected applied voltage is applied in the manner described above, the series of processes is ended, and the process returns to the main routine (not shown) to perform power control for the glow plugs 50 - 1 to 50 -n in the same manner as in the related art. In this case, the power control is performed using the corrected applied voltage calculated as described above.
In addition, as a method of inputting and storing the correction coefficient in the electronic control unit 101 , for example, it is possible to adopt a method of inputting and storing the correction coefficient in the electronic control unit 101 by stamping a barcode indicating the correction coefficient on a glow plug in advance and reading the bar code using a bar code reader connected to the electronic control unit 101 when the glow plug is mounted in a vehicle.
In addition, in the embodiment of the invention described above, the storage or the reading of a correction coefficient and control, such as power control, are performed by the electronic control unit 101 . However, for example, the power circuit 102 may be configured to include a microcomputer or a storage element, such as a RAM or a ROM, so that the storage or the reading of a correction coefficient and control, such as power control, are performed by the power circuit 102 .
According to the invention, compared with conventional cases, power driving compensating for variations in the temperature characteristics of a glow plug can be performed more finely. Therefore, since it is possible to obtain the heating temperature more stability and reliably, there is an effect that a glow plug driving control device with higher stability and reliability of control operation can be provided.
The invention is suitable for a glow plug driving control device of a vehicle for which further stability and reliability of the heating temperature when driving a glow plug are required. | The accuracy in controlling the heating temperature of a glow plug and the reliability of the control operation are improved.
An electronic control unit 101 is configured such that a standard applied voltage for glow plugs 50 - 1 to 50 -n is set according to the engine speed and the load conditions of the engine. In addition, a correction coefficient set in advance according to the temperature classification of the mounted glow plugs 50 - 1 to 50 -n is readably stored in the electronic control unit 101 as a correction coefficient map. By multiplying the standard applied voltage by a correction coefficient K read from the correction coefficient map and applying a voltage of the multiplication result to the glow plugs 50 - 1 to 50 -n as a driving voltage through the power circuit 102 to perform driving control, stable and reliable heating temperature control can be realized regardless of variations in the heating temperature characteristics. | 5 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of priority to U.S. Provisional Patent Application Ser. No. 61/246,085, filed 25 Sep. 2009 and entitled “GENETIC MANIPULATION OF THE AT-HOOK DOMAIN IN PLANT AHL GENES TO MODULATE CELL GROWTH,” which is incorporated herein by reference in its entirety.
STATEMENT REGARDING FEDERALLY-SPONSORED RESEARCH
[0002] This invention was made with government support under Contract No. DE-FG02-08ER15927 awarded by the Department of Energy (DOE). The Government has certain rights in the invention.
FIELD OF THE INVENTION
[0003] Particular aspects relate generally to modulation of cell growth in plants and plant parts, and in particular to compositions and methods comprising the use of plant (e.g., Camelina ) derived AHL genes and gene products for modulation of cell growth in plants. Particular aspects relate to manipulation of the AT-hook domain in plant (e.g., Camelina ) AHL genes, including manipulation of the AT-hook domain (e.g., AT-hook domain mutants and modifications including but not limited to nonsense, missence, deletions, substitutions, muteins, fusions, etc.) in novel exemplary sequences SEQ ID NOS:1-6, which have substantial utility for modulation of cell growth in plants. Additional aspects relate to modified plants, cells, or seeds comprising modified AHL genes (e.g., modified Camelina derived AHL genes) and gene products, and modified versions thereof.
BACKGROUND
[0004] The AT-hook motif nuclear localizing gene family. The Arabidopsis thaliana genome encodes 29 AHL gene members that are characterized by containing two conserved structural elements, the AT-hook motif and the PPC domain. These 29 AHL gene members have further evolved into two phylogenic clades (Street et al. 2008, FIG. 1 ). Clade I consists of intron-containing AHL genes with either one or multiple AT-hook motifs and a single PPC domain. Clade II members are intron-less with only a single AT-hook motif and PPC domain (Fujimoto et al., 2004; Street et al., Plant J, doi: 10.1111/j1365-313X.2007.03393.x (2008), hereby incorporated by reference in its entirety; FIG. 2 ). The Clade II genes SOB3 and ESC were initially characterized with previous DOE support (Street et al. 2008), as well as family members such as HRC.
[0005] The PPC Domain. The PPC domain consists of approximately 130 amino acids (Street et al. 2008, FIG. 2 ). The hydrophobic region at its C-terminus is essential for AHL1's nuclear localization (Fujimoto et al., 2004). However, no other biological function for this domain is known. The PPC domain exists as a single domain in proteins from Bacteria and Archaea. Whereas in plant species like Arabidopsis, it is intimately associated with the AT-hook motif (Fujimoto et al., 2004). This high conservation through evolution and the large number of family members identified in Arabidopsis suggests that this domain is important for plant development.
[0006] X-ray crystallography analysis of the thermophylic archea Pyrococcus horikoshii PPC domain at a 1.6 Å resolution reveals a trimer complex with the subunit-subunit contacting surface maintained by a hydrophobic region that is formed by several anti-parallel β-sheets (Lin et al., 2005; Lin et al., 2007). Secondary structure prediction of the SOB3 PPC domain suggests that it has the same arrangement of anti-parallel (β-sheets as in the P. horikoshii PPC protein. Herein, we conceived and have corroborated that Arabidopsis AHL proteins associate with each other in homo- or hetero-complexes and that the PPC domain is responsible for this interaction.
[0007] The AT-Hook Motif. The AT-hook motif has been shown to interact with A/T-rich stretches of DNA (Reeves and Nissen, 1990; Huth et al., 1997; Bewley et al., 1998). Three types of AT-hook motifs have been identified (Aravind and Landsman, 1998). The AHL proteins have the Type II AT-hook motif, with a central arginine-glycine-arginine (R-G-R) core element flanked by prolines (Street et al. 2008, FIG. 2 ). While the R-G-R core represents a concave surface and perfectly fits in the minor groove, the proline residues flanking this core region direct the rest of peptides out of the minor groove and provided millimolar-range binding affinity to DNA. The residues downstream of the R-G-R core provide additional affinity and specificity to DNA (Huth et al., 1997). The type II AT-hook motif in the AHL proteins has conserved sequences, glycine-serine-lysine-asparagine-lysine-x-lysine-x-proline, at carboxy end of the R-G-R core. This region is unique to the AHL protein family and has been suggested to provide extra DNA contact (Huth et al., 1997). During an EMS-induced sob3-D intragenic suppressor screen, a sob3-4 null allele and two missense alleles, sob3-5 and sob3-6 were identified to repress the suppression of hypocotyl growth (Street et al. 2008, FIG. 2 ). The sob3-6 mutation causes an R77>H conversion in the AT-hook motif whereas the sob3-5 lesion causes an adjacent G80>Q change demonstrating the importance of the AT-hook core and flanking conserved sequences for SOB3 function.
[0008] ESC has been shown to bind with A/T-rich DNA sequence in the promoter region of pea PRA gene (Lim et al., 2007). HRC, as well as AHL15, can bind the GNFEI (GA-negative feedback element I) of the gibberellins 3-oxidase (GA3ox) promoter, possibly as a means for regulating a GA-negative feedback loop (Matsushia et. al., 2007). AHL proteins in Catharanthus roseus have been found to bind the jasmonate-responsive element region in the promoter of ORCA3 (octadecanoid-derivative responsive Catharanthus AP2-domain) gene (Endt et al., 2007). In Specific Aim 3 we will examine the DNA binding properties of SOB3 and the sob3-5 and sob3-6 proteins with their mutated type II AT-hook motifs.
[0009] Over-expression of SOB3 and ESC represses hypocotyl growth in seedlings and induces robust plant growth in adults. Activation-tagging enhancer elements inserted upstream of the SOB3 promoter region generated the over-expressed dominant allele, sob3-D ( FIG. 3 ; Street et al., 2008). Over-expression of SOB3 represses light-grown hypocotyl elongation in both phyB-4 mutant and wild-type seedlings (Street et al. 2008, FIGS. 3A and B). Over-expression of ESC confers similar seedling phenotypes (Street et al. 2008, FIGS. 3C and D). In contrast, for adults, over-expression of SOB3, ESC, HRC, AHL18 and AHL22 results in more robust adult plants with elongated primary stem growth and expanded leaves ( FIG. 4 ; Jiang, 2004; Lim et al., 2007; Street et al., 2008; Xiao et al., 2009). Constitutive expression of AHL members also leads to delayed flowering and senescence (Lim et al., 2007; Street et al., 2008; Xiao et al., 2009). Long-day-grown sob3-D plants flowered approximately one week later than wild-type plants though the number of rosette leaves at flowering was similar for both genotypes. The same flowering phenotype is caused by over-expression of AHL22 and AHL18 (Xiao et al., 2009). ESC over-expression also delays flowering while enhancing photosynthesis in mature plants (Lim et al., 2007).
[0010] Analyzing the functions of AHL gene family based on gain-of-function studies hints at their roles in regulating various aspects of plant growth and development. Over-expression of AHL genes increases biomass via expanded leaf areas, enhanced primary stem growth and enlarged organ size together with enhanced photosynthesis capacity and delayed flowering and senescence. In fact, the HRC gene has been patented for increasing plant biomass (Jiang, 2004). However, focusing on these data can be misleading due to high levels and potential lack of specificity in gene expression. Therefore loss-of-function analysis must be coupled with over-expression studies in order to fully understand the genetic role of a given gene or (semi-) redundant gene family.
[0011] Loss-of-function analysis of SOB3 and ESC. The sob3-4 null allele (Q47>stop) was identified as an EMS-induced intragenic suppressor of the sob3-D short hypocotyl phenotype. The esc-8 null allele (Q43>stop) was obtained from the Seattle TILLING project (Till et al., 2003). Singe nulls are phenotypically wild-type as seedlings and adults. In contrast, the sob3-4 esc-8 double mutant has a significantly longer hypocotyl than the wild type in multiple fluence rates and wavelengths of light ( FIG. 5 ; Street et al., 2008). This loss-of-function analysis unequivocally demonstrates that SOB3 and ESC redundantly modulate light-mediating seedling development. Xiao et al. (2009) recently reported that RNAi-knockdown of SOB3 and AHL18 in an ESC- and AHL22-null background confers seedlings with longer hypocotyls than the wild type or ahl22 null, suggesting that all four AHL members may function redundantly to regulate hypocotyl growth.
[0012] Applicants have provided the most rigorous loss-of-function analysis for any members of the AHL gene family to date. Additional loss-of-function analysis will facilitate further understanding the biological roles of these DNA-binding proteins. According to certain embodiments, Applicants can generate and characterize higher order null alleles for AHL family members chosen based on previous studies and identified co-expression networks.
[0013] Two intragenic suppressor alleles, sob3-5 and sob3-6, confer dramatic long hypocotyl phenotypes. Double-null analysis of sob3-4 esc-8 demonstrates that SOB3 and ESC act redundantly to repress light-grown hypocotyl elongation. However, the relatively subtle long-hypocotyl phenotype suggests that other family members may also be involved in this process (Street et al. 2008). Two missense alleles, sob3-6 and sob3-5, confer much longer hypocotyls than the wild type or the sob3-4 esc-8 double null (Street et al. 2008, FIGS. 5 and 6 ). They both cause amino acid changes in and near the AT-hook motif respectively (Street et al. 2008, FIG. 2 ). The more severe allele of these two, sob3-6, is caused by a R77>H conversion in the first R of the R-G-R core region possibly abolishing the DNA binding capacity of this protein. The observation that this allele was originally identified as a heterozygous intragenic suppressor of sob3-D, coupled with a more severe phenotype than the sob3-4 esc-8 double mutant, suggests that the sob3-6 allele is acting as a dominant-negative mutation (Street et al. 2008). We present unpublished results that show the dominant-negative interpretation of the sob3-6 lesion.
SUMMARY OF EXEMPLARY EMBODIMENTS
[0014] Particular preferred aspects provide an isolated nucleic acid encoding a polypeptide comprising SEQ ID NO:3, SEQ ID NO:6, a polypeptide having at least 93% or at least 95% sequence identity with SEQ ID NO:3, or a polypeptide having at least 75% or at least 80% sequence identity with SEQ ID NO:6. In certain aspects, the nucleic acid comprises SEQ ID NO:1, SEQ ID NO:2, SEQ ID NO:4 or SEQ ID NO:5.
[0015] Additional exemplarly aspects provide an isolated polypeptide comprising SEQ ID NO:3, SEQ ID NO:6, a polypeptide having at least 93% or at least 95% sequence identity with SEQ ID NO:3, or a polypeptide having at least 75% or at least 80% sequence identity with SEQ ID NO:6.
[0016] Further exemplary aspects provide a Camelina AHL polypeptide having a mutation of the AT hook domain that confers a dominant negative phenotype as disclosed herein. In certain embodiments, the polypeptide comprises a mutation in the AT hook domain of SEQ ID NO:3, SEQ ID NO:6, of a polypeptide having at least 93% or at least 95% sequence identity with SEQ ID NO:3, or of a polypeptide having at least 75% or at least 80% sequence identity with SEQ ID NO:6. In particular aspects, the polypeptide lacks the AT hook domain thereof. In certain embodiments, the mutant polypeptide yet comprises an intact or functional PPC domain.
[0017] Yet additional exemplary aspects provide a method of generating modified plants, comprising introducing into, or engineering in a plant cell, a nucleic acid encoding a mutant AHL protein having a mutation of the AT hook domain that confers a dominant negative phenotype as disclosed herein, provided that if the mutant AHL protein comprises an Arabadodpis thaliana (AT) Sob3 mutant, that the plant cell is not an AT plant cell. In certain method embodiments, the mutant AHL protein comprises a mutant Sob3 or Esc polypeptide. In certain method embodiments, introducing into, or engineering in comprises at least one of plant breeding and recombinant DNA and/or transformation methods. In certain method aspects, the mutant AHL protein is based on, or derived from a Camelina, or Arabadodpis thaliana (AT) AHL protein. In certain embodiments of the methods, the plant cell is of Brassica, Arabidopsis, soybean ( Glycine max ), canola ( Brassica napus or B. rapa ), sunflower ( Helianthus annuus ), Crambe ( Crambe abysinnica ); Black Mustard; Yellow Mustard ( Sinapis alba ); Oriental Mustard ( Brassica juncea ); Broccoli ( Brassica oleracea italica ); Rapeseed ( Brassica napus ); Meadowfoam ( Limnanthes alba ), Radish ( Raphanus sativus ); Wasabi ( Wasabia japonica ); Horseradish ( Cochlearia Armoracia ); Cauliflower; Garden cress ( Lepidium sativum ); Watercress ( Nasturtium officinalis ); and Papaya ( Carica papaya ), canola (rape), wheat ( triticum ), rice, corn, or a monocot. In certain embodiment, the dominant negative phenotype comprises taller seedlings.
[0018] Yet further aspects, provide a recombinant or genetically modified plant or plant cell comprising a nucleic acid encoding a mutant AHL polypeptide having a mutation of the AT hook domain that confers a dominant negative phenotype as disclosed herein, provided that if the mutant AHL protein is an Arabadodpis thaliana (AT) Sob3 mutant, the plant or plant cell is not an AT plant or plant cell. In certain aspects, the mutant AHL protein comprises a mutant Sob3 or Esc polypeptide. In particular embodiments, the mutant AHL protein is based on, or derived from a Camelina, or Arabadodpis thaliana (AT) AHL protein. In certain aspects, the phenotype of the plant comprises taller seedlings. In certain aspects, the plant is derived using a method according to any one of claims 8 - 13 .
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] FIG. 1 shows sob3-6×sob3-D F1 generation plants partially suppress the sob3-D phenotype. (A) Hypocotyl length of F1 hybrids compared to sob3-D hypocotyls (B) Adult phenotype of sob3-6/sob3-D F1 hybrid, sob3-D, sob3-6 heterozygote and wild-type plants at 32 days after germination.
[0020] FIG. 2 shows over-expression of sob3-6 allele in wild-type Arabidopsis recapitulates the sob3-6 phenotype in seedlings and confers dwarfing in some adults. (A) Hypocotyl comparison of 5-day-old wild-type (Col-0), sob3-5, sob3-6 and six independent sob3-6 overexpression primary transformant lines. Scale bar=5 mm. (B)-(E) Various adult phenotypes observed in the sob3-6 primary transformant lines: similar to the wild type (B), semi-dwarf (C), dwarf (D) and severe dwarf (E).
[0021] FIG. 3 shows SOB3 and ESC interact with each other in Y2H assay. (A) SOB3 was used as prey(pACT2) and ESC was used as bait (pBTM116). Five individual colonies were picked and re-plated on SDII (selection medium containing leucine and histidine) or SDIV (selection medium without leucine and histidine). Pictures were taken 3 days after plating. (B) SOB3 was used as bait and ESC was used as prey.
[0022] FIG. 4 shows protein-protein interaction among SOB3, ESC and HRC proteins by BiFC. Onion epidermal cells were transformed with the indicated plasmid combination. A monomeric red fluorescent protein (pSAT6-mRFP) was used with each combination as a positive control. Each figure shows four channels observing the monomeric red fluorescent signal (I), yellow fluorescent signal (II), white field view (III) and overlapping view of I, II and III (IV).
[0023] FIG. 5 shows that a mutation in the AT-hook motif does not abolish the nucleus localization of AHL protein and protein-protein interaction. Onion epidermal cells were transformed with the indicated plasmid combination. A monomeric red fluorescent protein was also used with each pair for positive control. The esc-11 allele was created to harbor the same mutation as in sob3-6 allele.
[0024] FIG. 6A shows the phylogenic tree of AHL gene family taken from Street et al., 2008. AHL members that exist in each co-expression network are shown with symbols described in the legend table. AHL members that are not part of a co-expression network are marked with a cloud symbol. FIGS. 6B and 6C shows the co-expression pattern of the AHL gene family. (B) Co-expressed gene networks of AHL genes revealed by the ATTED-II database (Obayashi et al., 2007; Obayashi et al., 2009). Pairwise Pearson's correlation coefficients were indicated for each pair of co-expressed genes. (C) Thumbnail image of e-Northern results of indicated AHL genes generated by BAR (The Botany Array Resource) database (Toufighi et al., 2005). All publicly available micro-array data were used in this analysis.
[0025] FIG. 7 shows the effects of HERCULES (HRC1) overexpression in plants. Taken from Jiang 2004, U.S. Pat. No. 6,717,034, Method for modifying plant biomass.
[0026] FIG. 8 shows the hypocotyl length in cm of Camelina seedlings versus the days after planting. The graph shows the difference in hypocotyl length of Camelina seedlings between wildtype (non-transgenic; top panel) and Atsob3-6 overexpressing plants (transgenic; bottom panel).
[0027] FIG. 9 shows the hypocotyl length in cm of certain T2 generation Camelina seedlings.
[0028] FIG. 10 shows T3 generation Camelina seedlings over-expressing Atsob3-6 (right) compared to wild type syblings (left) after being planted on 1 cm of moist Palouse silt-loam and then covered with 8 cm of dry Palouse silt loam. Ten seedlings were placed in each pot. 30 to 50% of the transgenic seedlings emerged from this deep planting whereas no wild type plants did. After this experiment was completed, it was determined that both pots experienced 100% germination. Experiment has been repeated three times.
[0029] FIG. 11 shows that the weight of 100 T4 generation Camelina seeds over-expressing Atsob3-6 (right) is heavier when compared to a transgenic line expressing the empty-vector (left). The transformant line (right) also yields seedlings with longer hypocotyls than empty-vector control line.
[0030] FIG. 12 shows that the weight of 100 homozygous Arabidopsis sob3-6 mutant seeds (left) is heavier when compared to a wild-type control (right). Raw values are presented above the bars along with ±SEM.
[0031] FIG. 13 shows the weight of 100 T3 generation transgenic Arabidopsis seeds over-expressing Atsob3-6 compared to the wild type. Transformant-2 (far-right) is heavier when compared to the wild type (far-left) and Transformant-1 (center). Transformant-1 confers a hypocotyl phenotype that is the same as the wild type. Transformant-2 confers a longer hypocotyl than the wild-type. Raw values are presented above the bars along with ±SEM.
[0032] FIG. 14 shows that the esc-11 mutation also confers a long hypocotyl phenotype in Arabidopsis T1 transgenic seedlings. The esc-11 allele was created with the same mutation as sob3-6 using site-directed-mutagenesis. Wild-type (Col-0) were transformed with an empty vector control (far-left), the wild-type copy of ESC (ESCox1 and ESCox2) or with the esc-11 allele (esc-11ox1 to esc-11ox7). The ESCox and esc-11ox alleles were driven by the CaMV35S promoter. Scale bar=5 mm.
[0033] FIG. 15 shows that the overexpression of the SOB3 PPC domain and the linker region between the PPC domain and the AT-hook is sufficient to confer a long hypocotyl phenotype in T1 transgenic Arabidopsis seedlings. A wild-type (Col-0) seedling transformed with an empty vector control is shown on the left. A wild-type T1 seedling transformed with the linker region and the PPC domain driven by the CaMV35S promoter is shown on the right. Scale bar=2 mm.
DETAILED DESCRIPTION
[0034] Overview. Applicants generally use Arabidopsis seedling development as a barometer for exploring changes in plant growth in response to both external cues and internal signaling pathways. For example, to complement traditional loss-of-function genetic approaches, gain-of-function gene-over-expression strategies can be used to identify components which may be involved in light-mediated seedling development (Weigel et al., 2000). This activation tagging approach allows for identification of genes that are small and/or part of a functionally redundant family and thus, not easily identifiable in loss-of-function mutant screens (Neff et al., 1999; Turk et al., 2005; Ward et al., 2005; Ward et al., 2006; Zhang et al., 2006; Street et al., 2008).
[0035] sob3-D (ACTIVATION-TAGGED S UPPRESSOR O F PHYTOCHROME B -4, # 3 - D OMINANT) was identified in a screen for extragenic suppressors of the long-hypocotyl phenotype conferred by a weak photoreceptor mutation, phytochrome B-4 (Street et al., 2008). SOB3's closest family member, ESC AROLA (ESC), was identified in an independent activation-tagging screen (Weigel et al., 2000). These two genes belong to the A T- H OOK MOTIF NUCLEAR L OCALIZED (AHL) family which is defined by containing one or more AT-hook DNA-binding motif(s) and a P LANT AND P ROKARYOTE C ONSERVED/ D OMAIN OF U NKNOWN F UNCTION # 296 (PPC/DUF296) (Fujimoto et al., 2004).
[0036] Over-expression of SOB3/AHL29 or ESC/AHL27 confers repressed hypocotyl elongation for seedlings grown in the light but not in darkness. As adults, these gene-over-expression plants develop larger organs including expanded leaves and enlarged flowers and fruits together with delayed flowering and senescence (Street et al., 2008). Over-expression of other AHL gene members also enhances adult leaf and stem growth (Jiang, 2004; Lim et al., 2007; Xiao et al., 2009). Single loss-of-function mutants for either SOB3 (sob3-4) or ESC (esc-8) have phenotypes similar to the wild type. In contrast, the sob3-4 esc-8 double mutant confers enhanced seedling hypocotyl growth under continuous white, red, far-red and blue light. Taken together, SOB3, ESC, and possibly other AHL genes, such as the next closest family member H E RC ULES (HRC/AHL25), function in a redundant manner to regulate hypocotyl elongation in response to light at the seedling stage and possibly flowering time and biomass for adult plants. However, the mechanism of action for AHL proteins has until now remained unknown.
[0037] The present disclosure furthers knowledge of how SOB3, ESC, HRC and other related AHL gene family members regulate growth in seedlings as well as adult plants. Apoplicants' data indicates that the redundant relationship shared by SOB3, ESC and likely HRC results from physical interactions with each other in vivo. Further examination of the physical interactions between these and other AHL proteins is a key step towards understanding the biochemical mechanism by which the AHL gene family regulates plant growth. Structure/function analysis allows investigation of the roles of two conserved domains, the AT-hook motif and the PPC/DUF296 (PPC) domain, in protein-DNA and protein-protein interaction. Gain-of-function and loss-of-function analysis of a subset of AHL gene family members, accompanied with the study of the dominant-negative sob3-6 allele, allowed us to examine the role of this suite of genes in regulating hypocotyl growth, flowering time, adult stature, photosynthesis, senescence and other aspects of plant development. These present studies transform and extend the understanding of the mechanism by which the AHL gene family regulates plant growth and development.
[0038] The dominant-negative nature of sob3-6. The two missense alleles of Arabadopsis, sob3-5 and sob3-6, are quite interesting given that they each have more severe long-hypocotyl phenotypes than the sob3-4 esc-8 double mutant (Street et al. 2008; FIGS. 5 and 6 ).
[0039] SOB3 Over-Expression Suppresses the Long-Hypocotyl Phenotype of phyB-4.
[0000] SOB3 was identified in a gain-of-function activation-tagging mutant screen for novel, dominant suppressors of the long-hypocotyl phenotype conferred by the weak phyB allele, phyB-4 (Ward et al., 2005; Weigel et al., 2000). sob3-D phyB-4 T2 plants segregated as a single-locus T-DNA insertion and flanking genomic DNA was cloned by Kpn I-fragment plasmid rescue. Sequencing of the rescued plasmid and BLASTn analysis revealed that the transgene enhancer elements were inserted on chromosome I, 497 by upstream of the annotated open-reading-frame (ORF) Atlg76500. No other predicted ORFs were found in the 4.5 kb insert of the rescued plasmid. The accumulation of Atlg76500 transcript was elevated in sob3-D phyB-4 plants compared to the wild-type (Street et al. 2008, FIG. 1B ). Further, the over-expression seedling phenotypes were recapitulated by transforming phyB-4 plants with a transgene carrying a portion of the rescued plasmid containing the 35S enhancer elements, the Atlg76500 ORF, and flanking regions of genomic DNA (Street et al. 2008, FIG. 1 ). These results demonstrate that the sob3-D phenotype is caused by the over-expression of Atlg76500/SOB3 ( FIG. 1 ).
[0040] Although sob3-D hypocotyls were shorter when grown in white light in both wild-type (Col-0) and phyB-4 backgrounds, the hypocotyls elongated normally in the dark, indicating that the sob3-D mutant does not cause a general growth defect but perturbs development in a light-dependent manner (Street et al. 2008, FIG. 1A ). One possible explanation for the light dependency of the sob3-D seedling phenotype is that light regulates SOB3 expression. RT-PCR analysis of Atlg76500 from light- and dark-grown wild-type and phyB-4 seedlings, however, demonstrated similar levels of transcript accumulation, indicating that SOB3 is expressed in seedlings and is not light-regulated at the transcriptional level (Street et al. 2008, FIG. 1B ). The lack of light regulation of SOB3 points to the alternative possibility that SOB3 over-expression impinges on light-signaling pathways.
[0000] sob3-D Plants Exhibit Altered Cell Expansion Dynamics and Delayed Senescence
SOB3 over-expression also resulted in altered adult phenotypes. The first conspicuous adult sob3-D phenotype observed was the slower development of rosette structures relative to wild-type Col-0 plants. Fourteen-day-old long-day-grown (16 hrs light: 8 hrs dark) Col-0 plants were larger than sob3-D plants (Street et al. 2008, FIG. 2A ). This trend continued until 28 days after germination, when sob3-D leaves became larger than Col-0 (Street et al. 2008, FIG. 2A ). Though long-day-grown sob3-D plants flowered approximately one week later than wild-type plants, the number of rosette leaves at flowering was similar for both genotypes (Street et al. 2008, Supplemental FIG. 1 ). sob3-D phyB-4 plants showed a similar growth pattern as sob3-D plants (Street et al. 2008, Supplemental FIG. 2 ). sob3-D and sob3-D phyB-4 plants also senesced later than the wild-type. After 44 days of growth, phyB-4 and the wild-type began senescing, whereas sob3-D plants were still green and actively growing (Street et al. 2008, FIG. 2A , Supplemental FIG. 2 ). Eventually, sob3-D plants developed larger leaves and flowers than the wild-type (Street et al. 2008, FIG. 2B , C). The sob3-D mutation conferred similar phenotypes in a wild-type background (Street et al. 2008, FIG. 2 ).
[0041] The increased organ size caused by the sob3-D allele could result from increased cell proliferation, cell expansion, or a combination of both processes. To investigate the cause of increased organ size, epidermal imprints of 16, 23 and 30-day-old 4 th leaves of Col-0 and sob3-D were made and cell area determined. As shown in FIG. 2D (Street et al. 2008), sob3-D leaf epidermal cells were significantly smaller than Col-0 at 16 days. At 23 and 30 days, however, sob3-D epidermal cells were significantly larger than the wild-type (Street et al. 2008, FIG. 2D ). The increased leaf size can, therefore, be attributed to cell expansion, not cell proliferation. Taken together, SOB3 over-expression leads to a delay in cell expansion in the light, explaining the slower growth phenotypes exhibited in both seedlings and adult plants. SOB3 over-expression eventually leads to excessive cell expansion, leading to the over-growth phenotypes seen in sob3-D adult plants.
SOB3 is a Member of a Plant-Specific Protein Family
[0042] SOB3 encodes a protein containing a single AT-hook DNA-binding motif and a PPC (Plant and Prokaryotic Conserved) domain of unknown function (Fujimoto et al., 2004). A BLASTn analysis found one significant match in the Arabidopsis genome, Atlg20900/ESC (Weigel et al., 2000). There is synteny of several adjacent genes in the SOB3 and ESC chromosomal regions, suggesting that they may have arisen from a gene duplication event (Street et al. 2008, Supplemental FIG. 3 ). In addition, the ESC protein contains 74% (224/302) identical and 89% (270/302) similar amino acids when compared to SOB3 (Street et al. 2008, FIG. 3A ). SOB3 and ESC belong to a gene family in Arabidopsis designated AHL (AT-hook motif nuclear localized protein) with SOB3 and ESC being AHL29 and AHL27, respectively (Fujimoto et al., 2004). SOB3/AHL29 and ESC/AHL27 have identical AT-hook motifs and a highly conserved PPC domain, suggesting that these two proteins may have similar function (Street et al. 2008, FIG. 3A ). A BLASTp search revealed 28 annotated proteins similar to SOB3/AHL29 in Arabidopsis and homologs in plants with sequence data available (Street et al. 2008, Supplemental FIG. 4 ; Fujimoto et al., 2004). No SOB3/AHL29-like proteins containing both the AT-hook DNA-binding motif and the PPC domain were found in prokaryotes, fungi or animals, suggesting that SOB3/AHL29 is part of a conserved, plant-specific family of proteins (Fujimoto et al., 2004).
ESC Over-Expression Results in Phenotypes Similar to those Exhibited by sob3-D phyB-4 Plants
To determine whether ESC is similar to SOB3 in its gain-of-function state, transgenic plants over-expressing the ESC ORF (esc-OX) in the phyB-4 background were generated using a 5,044 by fragment of the rescued plasmid from the esc-1D activation tagged mutant (Weigel et al., 2000). Multiple independent T2 transgenic lines with increased levels of ESC transcript accumulation conferred short hypocotyls when compared to phyB-4 (Street et al. 2008, FIG. 3B , 3 C). esc-OX phyB-4 plants also had adult phenotypes similar to those displayed by sob3-D phyB-4 plants (Weigel et al., 2000). These data suggest that SOB3 and ESC can play similar roles in plant development.
SOB3 and ESC Proteins Accumulate in Hypocotyls
[0043] SOB3 and ESC transcripts were detected in seedlings (Street et al. 2008, FIG. 1B , 3 C, 3 D) but not adult leaves (Street et al. 2008, FIG. 3D ) using a RT-PCR assay. The Genevestigator public microarray resources indicated that SOB3 and ESC are expressed in seedlings as well as in root tissue and developing siliques (Zimmerman et al. 2004). To further explore the tissue-specific expression pattern of SOB3 and ESC in seedlings, transgenic plants harboring a reporter gene β-glucuronidase (GUS) translational fusion under control of the SOB3 or ESC native promoter were constructed (SOB3:SOB3-GUS and ESC:ESC-GUS). Multiple homozygous single-locus-insertion lines were analyzed. Homozygous lines had shorter hypocotyls compared to wild-type control plants under dim white light conditions, suggesting that the GUS-fusion transgenes are functional (Street et al. 2008, Supplemental FIG. 5 ).
[0044] GUS activity expressed from both SOB3:SOB3-GUS and ESC:ESC-GUS transgenes was observed primarily in the vascular systems of seedlings, including the hypocotyls, cotyledons and roots in both dark- and light-grown plants (Street et al. 2008, FIG. 4A-D ). In many lines, GUS activity was observed throughout the width of the hypocotyl (Street et al. 2008, FIG. 4A-D ). GUS activity was also observed in the tips of cotyledons. In root tissues, GUS activity was observed in the root vasculature as well as the budding lateral roots (Street et al. 2008, FIG. 4E , F). SOB3:SOB3-GUS and ESC:ESC-GUS lines were identical in their overall staining patterns in seedling tissues. These results support the hypothesis that SOB3 and ESC act in similar tissues during seedling development.
SOB3 and ESC Localize to the Nucleus
[0045] To determine the sub-cellular localization of SOB3 and ESC, transgenic lines expressing a YFP-SOB3 or YFP-ESC translational fusion driven by the 35S promoter were constructed and live root tissue observed under a UV light. Plants transformed with these constructs displayed the short-hypocotyl phenotype typical of sob3-D plants, indicating that the fusion protein is functional. As shown in FIG. 4G-H , the YFP-SOB3 signal was detected in the nucleus of root-hair cells as confirmed by Hoechst nuclear counterstain. Similar results were obtained for a 35S:YFP:ESC fusion construct (Street et al. 2008, Supplemental FIG. 6 ). These protein localization results are consistent with the hypothesis initially suggested by the presence of the AT-hook domain that SOB3 and ESC are nuclear proteins that likely interact with DNA.
Identification of SOB3 and ESC Loss-of-Function Alleles
[0046] Although gain-of-function/over-expression phenotypes and protein expression patterns provided clues as to SOB3 and ESC function, such as a possible role in light-dependent seedling development and a negative role in cell expansion processes, loss-of-function mutants were identified to further explore the role of these genes during seedling development. The SigNAL T-DNA insertion library contains three independent transgenic lines in which a T-DNA is inserted in the SOB3 promoter region (Alonso et al., 2003). Homozygous sob3-1, sob3-2, and sob3-3 plants carried T-DNAs inserted 4 bp, 3 bp and 50 bp upstream of the annotated start codon, respectively (Street et al. 2008, FIG. 5A ). No obvious morphological seedling or adult phenotype was observed in any of these sob3 T-DNA alleles (data not shown). The detection of SOB3 transcript in all of these T-DNA insertion mutants leaves open the possibility that they may not be null alleles (Street et al. 2008, FIG. 5B ).
[0047] Since none of the T-DNA insertion mutations could be confirmed as null alleles, an ethyl methanesulfonate (EMS) suppressor screen of sob3-D phyB-4 was undertaken to isolate loss-of-function alleles within the SOB3 ORF. M2-generation EMS-mutagenized pools of sob3-D phyB-4 plants were screened for the recovery of the phyB-4 long-hypocotyl phenotype. In a screen of approximately 100,000 M2 seedlings derived from 2500 M1 plants, three putative alleles within the SOB3 ORF were identified: sob3-4, sob3-5, and sob3-6 (Street et al. 2008, FIG. 5A , C). The sob3-4 allele caused a glutamine to a stop codon (Q47>stop) change before the two conserved domains in SOB3 (Street et al. 2008, FIG. 5A , C). In contrast, the sob3-5 and sob3-6 missense alleles caused amino acid changes near and within the putative AT-hook DNA-binding domain, respectively (Street et al. 2008, FIG. 5A , C). The sob3-5 allele caused a glycine to glutamine (G80>Q) change just outside the DNA-binding domain, whereas the sob3-6 allele caused an arginine to histidine (R77>H) change in the central amino acid of the AT-hook DNA-binding domain. The positions of the amino acid changes caused by the sob3-5 and sob3-6 alleles suggest that the AT-hook domain plays an important role in SOB3 function. Of the three new alleles generated in this intragenic suppressor screen, the sob3-4 nonsense allele was the best candidate for a null mutation based on gene structure and was chosen for further genetic characterization. As shown in Table I (Street et al. 2008), the sob3-4 mutation segregated in a Mendelian fashion in F2 populations generated from self-pollination of heterozygous SOB3/sob3-4 (sob3-D) parents (Table I, Street et al. 2008).
[0048] Nine mutant alleles of ESC were obtained from the Seattle TILLING project (Till et al., 2003). The esc-8 allele was chosen for further characterization as it contained a nonsense mutation (Q43>stop) before any of the conserved domains and was therefore likely to be a null allele ( FIG. 5D , Street et al. 2008). The esc-8 allele also segregated in a Mendelian fashion (Table I, Street et al. 2008).
Analysis of SOB3 and ESC Loss-of-Function Phenotypes
[0049] An F2 population segregating both alleles was used to generate the sob3-4 esc-8 double mutant, as well as wild-type, sob3-4, and esc-8 homozygotes as controls. None of the single or double mutants had a significant morphological phenotype in adult plants. For example, both sob3-4 and esc-8 single mutants, as well as the sob3-4 esc-8 double mutant, flowered at the same time as individuals in the wild-type sibling line (Supplemental FIG. 7 , Street et al. 2008).
[0050] The loss-of-function mutants, however, did exhibit a light-dependent hypocotyl length phenotype at the seedling stage, further supporting the hypothesis that SOB3 and ESC play a role in seedling development. Since sob3-D and esc-OX gain-of-function mutations conferred shorter hypocotyls in the light ( FIG. 1A , 3 B, Street et al. 2008), the loss-of-function lines were used to perform fluence-rate-response assays (FRRAs) to test the hypothesis that the loss-of-function single mutants and the sob3-4 esc-8 double mutant would have the opposite phenotype. Under low-fluence-rates of white light, sob3-4 esc-8 seedlings had longer hypocotyls when compared to the wild-type or either single mutant ( FIG. 6A , Street et al. 2008). A second double mutant using the sob3-2 T-DNA allele, sob3-2 esc-8, also exhibited a long-hypocotyl phenotype when grown in dim white light ( FIG. 6B , Street et al. 2008). These results suggest that SOB3 and ESC are functionally redundant negative modulators of hypocotyl elongation, acting in one or more light-signaling pathways.
[0051] Single mutants carrying the sob3-6 missense allele also had a long-hypocotyl phenotype in the light compared to wild-type plants ( FIG. 6C , Street et al. 2008), although sob3-4 nonsense mutants did not. The phenotype of the sob3-6 allele, which contains both the 35S enhancer and a missense mutation, suggests that over-expression of a protein with a mutated AT-hook domain confers a dominant-negative phenotype. Consistent with this hypothesis, a F1-generation cross between sob3-6 and sob3-D parents generated F1 hybrids with less severe sob3-D seedling and adult phenotypes, suggesting that the sob3-6 mutation suppresses the sob3-D allele ( FIG. 1 ).
[0000] Interaction of Photoreceptor Mutations with sob3 and esc Loss-of-Function Mutations
[0052] To determine whether a particular photoreceptor pathway is involved in the altered de-etiolation response of sob3-4 esc-8 double mutants, FRRAs were carried out in continuous far-red, red and blue light. A significant difference in the double mutant relative to the wild-type and single mutants was observed in all three monochromatic light conditions under all fluence rates tested (Street et al. 2008, FIG. 6D , 6 E, 6 F). Furthermore, RT-PCR analysis showed no differences for accumulation of PHYA, PHYB, and CRY1 transcripts in the sob3-4 esc-8 and wild-type genetic backgrounds, suggesting that expression of these major photoreceptors are not altered (data not shown).
[0053] Triple mutants were generated containing sob3-4, esc-8 and null alleles of the far-red (phyA-211), red (phyB-9) and blue (cry-103) photoreceptors. These mutants were grown in far-red, red, and blue light conditions in which the sob3-4 esc-8 double mutant conferred a long-hypocotyl phenotype. In far-red light, hypocotyls of the sob3-4 esc-8 phyA-211 triple mutant were not significantly longer than hypocotyls of phyA-211 siblings (Street et al. 2008, FIG. 7A ). This epistatic relationship suggests that SOB3 and ESC function downstream in the PHYA-far-red light pathway since PHYA is required to see the effect of sob3 and esc loss-of-mediated function mutations on hypocotyl elongation. In contrast, both the sob3-4 esc-8 phyB-9 and sob3-4 esc-8 cry-103 triple mutants had significantly longer hypocotyls than the single mutant photoreceptor lines (Street et al. 2008, FIG. 7B , 7 C). These additive effects support the interpretation that the SOB3 and ESC activity is not limited to the PHYB- or CRY-mediated light signaling pathways.
[0054] SOB3 and ESC are involved in seedling development. Both SOB3 and ESC were identified through activation tagging mutagenesis and have similar gain-of-function phenotypes ( FIG. 1 ; Weigel et al., 2000). The sob3-D and esc-OX adult phenotypes include slower development, delayed senescence and eventually larger organs with larger cell size, suggesting a role for SOB3 and ESC in cell expansion or differentiation (Street et al. 2008, FIGS. 1 and 2 ). The light-specific short-hypocotyl phenotype in these gain-of-function mutants suggests that SOB3 and ESC are involved in light-mediated seedling development (Street et al. 2008, FIGS. 1 and 3 ). It is possible to reconcile the seedling short hypocotyl phenotype with the adult large organs if sob3-D plants are slower growing than the wild-type in the light.
[0055] Furthermore, the similar gain-of-function phenotypes and the high DNA and protein sequence similarity between SOB3 and ESC suggest that these two genes are functionally redundant. The high degree of synteny around these two loci suggests that these genes are paralogs that have arisen via gene duplication (Street et al. 2008, Supplemental FIG. 3 ). This hypothesis is further supported by the observation that SOB3 and ESC are encompassed by larger regions predicted to arise by a chromosomal duplication event ( Arabidopsis Genome Initiative, 2000). Although gain-of-function analyses can provide clues to gene function, the results should also be supported with loss-of-function experiments.
[0056] Loss-of-function sob3-4 esc-8 double mutant seedlings were less sensitive to white and monochromatic red, far-red and blue light, demonstrating that SOB3 and ESC can act redundantly. Phytochromes A and B are the primary far-red and red photoreceptors involved in hypocotyl responsiveness to light, respectively, whereas cryptochromes mediate blue light response (for review see: Franklin et al., 2005; Liscum et al., 2003; Neff et al., 2000). The observed sob3-4 esc-8 mutant phenotype suggests that SOB3 and ESC are negative modulators of seedling hypocotyl elongation and act as downstream integrators of light signaling. Further supporting this hypothesis is the phenotype of the sob3-4 esc-8 phyA-211 triple mutants compared to the phyA-211 single mutant (Street et al. 2008, FIG. 7A ). This result suggests that PHYA is necessary to observe the sob3-4 esc-8 double mutant phenotype. Alternatively, since PHYA is the only far-red light receptor, it is also possible that light is required to see the effect of SOB3 and ESC loss-of-function. Native-promoter translational-GUS-fusion staining patterns were similar in light and dark grown seedlings (Street et al. 2008, FIG. 5 ). Since the protein distribution is similar in the light and dark, it is possible that SOB3/AHL29 and ESC/AHL27 protein activity is different in the light and dark. Taken together, these data support the hypothesis that SOB3 and ESC are downstream modulators of light-mediated hypocotyl responses.
[0057] Genetic and biochemical studies have revealed a complex network of individual interacting components necessary for a plant to properly interpret its light environment (for review see: Franklin et al., 2005; Moller et al., 2002; Neff et al., 2000). Phytochromes and cryptochromes have been shown to have partially redundant roles in seedling development (Lin et al., 1998; Neff and Chory, 1998; Ohgishi et al., 2004). The first downstream component identified, HY5, encodes a bZIP transcription factor that also has a long hypocotyl in multiple qualities of light, as well as other organ-development phenotypes, and may be an example of a downstream integrator of light and hormone responses (Cluis et al., 2004; Koornneef et al., 1980; Oyama et al., 1997). A HY5 homolog, HYH, was found to have some overlapping functions with HY5, particularly in blue light (Holm et al., 2002). SOB3 and ESC are similar in that they act partially redundantly in seedling development.
[0058] SOB3 and ESC are part of a conserved, plant-specific gene family. SOB3 and ESC are members of a family of genes that encode proteins containing an AT-hook motif (Fujimoto et al. 2004). AT-hook motifs are conserved in eukaryotes and some bacteria and are found in a wide variety of proteins involved in nuclear functions (Aravind and Landsman, 1998). The best characterized of this group are the High Mobility Group A (HMGA) proteins. HMGA proteins, which contain multiple AT-hook domains and are associated with cell proliferation or differentiation, are architectural transcription factors that recognize AT-rich stretches of DNA, (for review see: Grasser, 2003; Klosterman and Hadwiger, 2002; Reeves, 2001).
[0059] The Rice HMGA protein, PF1, is able to bind and enhance the activity of the Rice PHYA promoter suggesting a gene regulatory role for AT-hook proteins in photomorphogenesis (Martinez-Garcia and Quail, 1999). Single AT-hook domain containing proteins such as SOB3 and ESC are hypothesized to bind DNA and associate with the nuclear matrix (Fujimoto et al., 2004; Morisawa et al., 2000). A SOB3/ESC family member, AHL1, is suggested to encode a nuclear localized matrix attachment region (MAR) protein (Fujimoto et al., 2004). MARs are AT-rich sequences that attach chromosomal loops to the protein nuclear matrix and may play a role in transcriptional regulation (Paul and Ferl, 1998; Rudd et al., 2004). Recent work with other members of the SOB3/ESC gene family suggest that they are able to bind specific gene promoters involved in hormone responses (Matsushita et al., 2007; Vom Endt et al., 2007). These observations suggest that SOB3 and ESC act through DNA binding of AT-rich regions and act as accessory transcription factors.
[0060] SOB3 and ESC affect cell expansion. The opposite hypocotyl phenotypes of light-grown sob3-4 esc-8 and sob3-D mutants are most likely due to differential cell expansion, as hypocotyl growth in Arabidopsis involves cell elongation, not division (Gendreau et al., 1997). The capability of cells to expand in sob3-D mutants is not impaired as they elongate normally in the dark (Street et al. 2008, FIG. 1A ). This result suggests that there is a role for SOB3 and ESC as negative regulators of hypocotyl elongation in the light.
[0061] The sob3-D and esc-OX enlarged adult organ size phenotype is also likely to be due to cell expansion, since epidermal cell size is increased in these over-expressing plants (Street et al. 2008, FIG. 2A ). sob3-D and esc-OX plants take longer to develop compared to the wild-type and it is possible that this delay is due to an extended period of cell proliferation before cell differentiation and expansion. Leaves of sob3-D and esc-OX are twisted and not planar like a wild-type leaf, suggesting that the genetic program that determines wild-type leaf shape is disrupted in these plants. Genes such as the TCP (teosinte-branched, cycloidia, PCNA) family of transcription factors have been shown to be involved in this process by affecting cell proliferation and growth (Li et al., 2005; Nath et al., 2003; Palatnik et al., 2003).
[0062] Cell growth, division, expansion, endoreduplication, and differentiation are all factors involved in determining cell size, number and a plant's ultimate organ morphology (De Veylder et al., 2002; Grandjean et al., 2004; Li et al., 2005; Reddy and Meyerowitz, 2005; Sugimoto-Shirasu et al., 2005). It is an open question as to how all of these processes interrelate, though some progress has been made in identifying important components of cell state determinants and how this alters organ development. For example, loss-of-function of ANT plants have smaller aerial organs due to a lack of cell proliferation but have larger cells, due to a compensation mechanism (Mizukami and Fischer, 2000). ANT over-expression has the opposite phenotype, though unlike sob3-D and esc-OX plants, rosette leaf morphology is normal with wild-type cell size (Mizukami and Fischer, 2000). A gene hypothesized to act upstream of ANT, ARGOS, has a similar over-expression phenotype as ANT and is affected by auxin signaling (Hu et al., 2003). The closest paralog of SOB3/AHL29 and ESC/AHL27, H E RC ULES/AHL25 (HRC), also increases adult organ size when over-expressed (Jiang, 2004). SOB3, ESC and other gene family members can clearly affect adult organ morphology when over-expressed, suggesting an important role in plant architecture and a fundamental role in individual plant cells. The lack of an obvious adult phenotype in the sob3-4 esc-8 double mutant suggests that SOB3 and ESC may not play a role in adult development. Alternatively, other gene family members such as HRC may act redundantly with SOB3 and ESC in adult tissues.
[0063] Our studies facilitate determining the mechanisms by which SOB3 and ESC affect development. Without being bound by mechanism, it is possible that they act as transcription factors to regulate the expression of specific genes. The fact that SOB3 and ESC appear to act downstream of the photoreceptor network raises the possibility that they are part of a negative cell-expansion regulatory mechanism receiving input from the various signaling cascades of individual photoreceptors. Based on the GUS-fusion-expression data, SOB3/AHL29 and ESC/AHL27 are localized to the same tissues in seedlings in the light and the dark. Perhaps SOB3/AHL29 and ESC/AHL27 activity is mediated by post-translational modification in the light, or that SOB3/AHL29 and ESC/AHL27 proteins require the expression of genes specific to light-mediated development to affect hypocotyl elongation. Determining DNA binding sites and protein interacting partners as well as characterizing their loss-of-function phenotypes will shed more light on the roles the AHL gene family play in plant development.
Comparison of Camelina Seedlings Over-Expressing Atsob3-6 (Right) Compared to Wild Type Syblings
[0064] FIG. 10 shows T3 generation Camelina seedlings over-expressing Atsob3-6 (right) compared to wild type syblings (left) after being planted on 1 cm of moist Palouse silt-loam and then covered with 8 cm of dry Palouse silt loam. Ten seedlings were placed in each pot. 30 to 50% of the transgenic seedlings emerged from this deep planting whereas no wild type plants did. After this experiment was completed, it was determined that both pots experienced 100% germination. Experiment has been repeated three times.
[0065] FIG. 11 shows that the weight of 100 T4 generation Camelina seeds over-expressing Atsob3-6 (right) is heavier when compared to a transgenic line expressing the empty-vector (left). The transformant line (right) also yields seedlings with longer hypocotyls than empty-vector control line.
[0066] FIG. 12 shows that the weight of 100 homozygous Arabidopsis sob3-6 mutant seeds (left) is heavier when compared to a wild-type control (right). Raw values are presented above the bars along with ±SEM.
[0067] FIG. 13 shows the weight of 100 T3 generation transgenic Arabidopsis seeds over-expressing Atsob3-6 compared to the wild type. Transformant-2 (far-right) is heavier when compared to the wild type (far-left) and Transformant-1 (center). Transformant-1 confers a hypocotyl phenotype that is the same as the wild type. Transformant-2 confers a longer hypocotyl than the wild-type. Raw values are presented above the bars along with ±SEM.
[0068] FIG. 14 shows that the esc-11 mutation also confers a long hypocotyl phenotype in Arabidopsis T1 transgenic seedlings. The esc-11 allele was created with the same mutation as sob3-6 using site-directed-mutagenesis. Wild-type (Col-0) were transformed with an empty vector control (far-left), the wild-type copy of ESC (ESCox1 and ESCox2) or with the esc-11 allele (esc-11ox1 to esc-11ox7). The ESCox and esc-11ox alleles were driven by the CaMV35S promoter. Scale bar=5 mm.
[0069] FIG. 15 shows that the overexpression of the SOB3 PPC domain and the linker region between the PPC domain and the AT-hook is sufficient to confer a long hypocotyl phenotype in T1 transgenic Arabidopsis seedlings. A wild-type (Col-0) seedling transformed with an empty vector control is shown on the left. A wild-type T1 seedling transformed with the linker region and the PPC domain driven by the CaMV35S promoter is shown on the right. Scale bar=2 mm.
[0070] In the following Examples 1-19, Applicants have, inter alia, cloned novel Camelina derived AHL genes and gene products for modulation of cell growth in plants. Particular aspects provide for manipulation of the AT-hook domain in Camelina AHL genes, including manipulation of the AT-hook domain (e.g., AT-hook domain mutants and modifications including but not limited to nonsense, missence, deletions, substitutions, muteins, fusions, etc.) in novel sequences SEQ ID NOS:1-6, which have substantial utility for modulation of cell growth in plants. Additional aspects provide modified plants comprising Camelina derived AHL genes and gene products, and modified versions thereof.
Example 1
Multiple T1 Transgenic Events Expressing CaMV35S:sob3-6 Recapitulated the Elongated Phenotype of the Backcrossed sob3-6 allele, some of which are Shown to be Even More Severe than the Original sob3-6 Lesion
[0071] Applicants' initial focus was on sob3-6 since this lesion is in the absolutely conserved AT-hook core and the seedling phenotype is more severe than sob3-5. We backcrossed this mutant with the wild type two times. In each backcross, the sob3-6 long-hypocotyl phenotype behaves as a single-locus dominant/semi-dominant trait that is 100% linked to the adjacent activation-tagging T-DNA. We have also over-expressed, in wild-type plants using Agrobacterium strain GV3101 and the floral dipping transformation method (Clough and Bent, 1998), the sob3-6 cDNA driven by the constitutive cauliflower mosaic virus 35S (CaMV 35S) promoter. Multiple T1 transgenic events expressing CaMV35S:sob3-6 have recapitulated the elongated phenotype of the backcrossed sob3-6 allele, some of which are even more severe than the original sob3-6 lesion ( FIG. 2A ). The dominant nature of this allele and the fact that the resulting phenotype is more severe than the long-hypocotyl conferred by the sob3-4 esc-8 loss-of-function mutant strongly supports the hypothesis that this is indeed a dominant-negative allele caused by a disruption of a conserved amino acid in the AT-hook core.
[0072] According to particular aspects of the present invention, the nature of the sob3-6 allele coupled with the X-ray crystallography analysis of the P. horikoshii PPC domain at suggests a model where SOB3 interacts with itself, perhaps via the PPC domain, and that each interacting partner requires a functional AT-hook core to properly bind DNA. Given the relatively strong phenotype of the original sob3-6 allele and the even more severe phenotypes in some CaMV35S:sob3-6 recapitulation lines ( FIG. 2A-E ), we conceived that SOB3 also interacts with other AHL family members such as ESC or HRC and that these hetero-interaction complexes are being titrated out by the sob3-6 mutant protein. Alternatively SOB3 and other AHL members could share similar non-AHL interacting partners that are being titrated away by the sob3-6 mutant protein. In either case, the extreme dwarf phenotypes found in some CaMV35S:sob3-6 expressing lines suggest that the AHL family plays an important role in seedling and adult plant development.
Example 2
SOB3 was shown to Associate with ESC
[0073] Protein-protein interaction studies. We first tested the hypothesis that SOB3 can associate with ESC using a yeast two-hybrid (Y2H) approach. For the Y2H assay, a lexA-based system was used consisting of pBTM116-D9 as a bait plasmid and pACT2 (Clontech, Palo Alto, Calif.) as a prey plasmid, together with the yeast reporter strain L40ccU3. Coding sequences of SOB3 and ESC proteins were recombined into both the bait and prey vectors via Gateway® reactions (Invitrogen, Carlsbad, Calif.). Our preliminary Y2H results suggest that SOB3 can associate with ESC ( FIG. 3 ).
Example 3
SOB3, ESC and HRC were shown to Localize to the Nucleus and Physically Interact with Themselves and Each Other In Vivo
[0074] We further examined these interactions in planta using a transient Bimolecular Fluorescence Complementation (BiFC) Assay with onion epidermal cells biolistically transformed with Gateway® compatible vectors derived from pSAT4-DEST-n(1-174)EYFP-C1 and pSAT5-DEST-c(175-end)EYFP-C1(B) (Citovsky et al., 2006). The cDNAs for SOB3, ESC and HRC were cloned into each BiFC plasmid as in-frame translational fusions with either the N- or C-terminal half of a yellow fluorescent protein (YFP). Empty vectors were used as negative controls. Pairs of BiFC plasmids together with the pSAT6-mRFP plasmid encoding a red fluorescent protein (RFP) were co-bombarded into onion epidermal cells using a PDS-1000/He Biolistic transformation system (BIO-RAD). Reconstructed fluorescence was examined after 40 hours of incubation in the dark with a Zeiss LSM 510 META confocal microscope. The monomeric red fluorescence from the RFP was used to identify successful transformation into onion cells ( FIG. 4 ). The fluorescence from reconstructed YFP observed in FIG. 4 A-I shows that SOB3, ESC and HRC localize to the nucleus and physically interact with themselves and each other in vivo. In the BIFC assay using negative controls (data not shown), yellow fluorescence could not be observed.
Example 4
sob3-6 and esc-11 Were Shown to also Associate with Each Other and with Themselves
[0075] Mutations in the AT-hook core motif do not abolish nuclear localization or protein-protein interaction. The AT-hook motif of AHL1 is essential for its A/T-rich DNA binding ability (Fujimoto et al., 2004). However, the AT-hook motif also contributes to the nuclear localization for high mobility group proteins (Sgarra et al., 2006; Cattaruzzi et al., 2007). Thus, it is possible that the sob3-6 protein may be disrupting its own activity and/or that of other family members by abolishing nuclear localization. We used the BiFC assay to examine if this mutation in the AT-hook motif affects the sob3-6 protein nuclear localization and its association with wild-type SOB3 and ESC. In addition, we used site-directed mutagenesis to generate an ESC cDNA with the same conserved mutation as in sob3-6: esc-11. BiFC analysis demonstrates that both the sob3-6 and esc-11 proteins can enter the nucleus and associate with wild-type SOB3 and ESC proteins. Furthermore, sob3-6 and esc-11 can also associate with each other and with themselves ( FIG. 5 ). These results demonstrate that the sob3-6 and esc-11 mutations do not abolish nucleus localization or protein-protein interactions between AHL family members.
Example 5
Using PCR, Cloned cDNAs Similar to SOB3 and ESC were Obtained from Camelina, Demonstrating that the AHL Gene Family Exists in this Potential Oil-Seed Crop
[0076]
[0000]
Camelina ESC cDNA sequence 950 bp (SEQ ID NO: 1; coding
sequence):
TANAGCGGTGGACTTCTAGATCTTTCTAAACCTCTTCAGACCGGAGATTCACCACCA
GCACCTTCAACCGCAGGGTGGAATCAATCTTATTGACCAGCATCATCATCAGCATCA
GCAGCAACAACAACAACAACAACAGCMACCGTCGG ATG ATTCAAGAGAATCTGAA
CACTCAAACAAGGATCATCATCAACAGGGTCGACCCCGATTCAGACCCGAATACAT
CAAGCTCAACACCCGGGAAACGTCCACGTGGACGTCCGCCAGGATCTAAGAACAAA
GCAAAGCCACCGATCATAGTAACCCGTGACAGCCCCAACGCGCTTAGATCTCACGT
CCTTGAAGTATCTCCCGGAGCTGATATAGTTGAGAGTGTTTCCACTTACGCTAGGCG
GAGAGGGAGAGGCGTCTCCGTTTTAGGAGGGAACGGCACCGTTTCTAACGTCACTC
TCCGTCAGCCAGTCACTCCCGGAAACGGTGGTGGTGTGTCCGGAGGAGGAGGAGGA
GGAGTTGTGACTTTACATGGAAGATTTGAGATTCTTTCACTAACGGGGACTGTTTTG
CCACCTCCTGCGCCGCCTGGTGCAGGTGGTTTGTCAATATTTCTAGCCGGTGGGCAA
GGTCAGGTTGTTGGAGGAAGCGTGGTGGCTCCGCTTATTGCATCAGCTCCAGTTATA
CTAATGGCTGCTTCGTTCTCAAATGCGGTTTTCGAGAGACTACCAATGGAAGAGGA
AGAAGAAGAAGGTGCTGGTGCTGGCGGAGGGGGAGGAGGAGGACCACCGCAGATG
CAGCAAGCTCCCTCAGCATCGCCTCCGTCAGGCGTGACCGGTCAGGGACAGTTAGG
AGGTAATGTGGGTGGTTATGGGTTTTCTGGTGATCCTCATTTGCTTGGATGGGGAGC
TGGAACACCTTCAAGACCACTATTT TAA TCGAANTTAAANTCCNGAATT
Camelina Esc ORF 780 bp (SEQ ID NO: 2):
ATG ATTCAAGAGAATCTGAACACTCAAACAAGGATCATCATCAACAGGGTCGACCC
CGATTCAGACCCGAATACATCAAGCTCAACACCCGGGAAACGTCCACGTGGACGTC
CGCCAGGATCTAAGAACAAAGCAAAGCCACCGATCATAGTAACCCGTGACAGCCCC
AACGCGCTTAGATCTCACGTCCTTGAAGTATCTCCCGGAGCTGATATAGTTGAGAGT
GTTTCCACTTACGCTAGGCGGAGAGGGAGAGGCGTCTCCGTTTTAGGAGGGAACGG
CACCGTTTCTAACGTCACTCTCCGTCAGCCAGTCACTCCCGGAAACGGTGGTGGTGT
GTCCGGAGGAGGAGGAGGAGGAGTTGTGACTTTACATGGAAGATTTGAGATTCTTT
CACTAACGGGGACTGTTTTGCCACCTCCTGCGCCGCCTGGTGCAGGTGGTTTGTCAA
TATTTCTAGCCGGTGGGCAAGGTCAGGTTGTTGGAGGAAGCGTGGTGGCTCCGCTT
ATTGCATCAGCTCCAGTTATACTAATGGCTGCTTCGTTCTCAAATGCGGTTTTCGAG
AGACTACCAATGGAAGAGGAAGAAGAAGAAGGTGCTGGTGCTGGCGGAGGGGGAG
GAGGAGGACCACCGCAGATGCAGCAAGCTCCCTCAGCATCGCCTCCGTCAGGCGTG
ACCGGTCAGGGACAGTTAGGAGGTAATGTGGGTGGTTATGGGTTTTCTGGTGATCCT
CATTTGCTTGGATGGGGAGCTGGAACACCTTCAAGACCACTATTT TAA
Camelina Esc amino acid sequence (SEQ ID NO: 3):
MIQENLNTQTRIIINRVDPDSDPNTSSSTP GKRPRGRPPGSKNK AKPPIIVTRDSPNA LRSH
VLEVSPGADIVESVSTYARRRGRGVSVLGGNGTVSNVTLRQPVTPGNGGGVSGGGGGG
VVTLHGRFEILSLTGTVLPPPAPPGAGGLSIFLAGGQGQVVGGSVVAPLIASAPVILMAA
SFSNAVFE RLPMEEEEEEGAGAGGGGGGGPPQMQQAPSASPPSGVTGQGQLGGNVGG
YGFSGDPHLLGWGAGTPSRPLF*
Camelina sob3 cDNA sequence 873 bp (SEQ ID NO: 4; reverse
coding sequence):
CANANNGCGGNCANGAANGTGGATACTTTCACAACCTCTTTCAGACCTGACCTTCA
TCGCCAACTTCAACYTCAGCCTCATCTCCACCCTCTGCCTCAACCTCAACCTCAACC
TGAGCCTCAGCAACAACAATCAG ATG ATGAATCTGACTCCAACAAGGATCCGGGTT
CCGACCCGGTTACCTCGAGTTCAAACTCCTGGGAAGCGTCCACGTGGGCGTCCTCCG
GGATCTAAGAACAAGCCGAAGCCACCGGTGATAGTGACAAGAGATAGCCCCAACG
TGCTTAGATCTCATGTTCTTGAAATCTCATCTGGAGCCGACATAATTGAGTGCGTTA
ACACTTACGCTCGCCGGAGAGGGAAAGGTGTCTCCATTCTCAGTGGTAACGGCACG
GTAGCTAACGTCAGCATCCGTCAGCCGGCAACGGCTCATGCGACTAATGGTGGAGC
CGGAGGTGTTGTTTCTTTACATGGAAGGTTTGAGGTGCTTTCCATCACTGGTACGGT
GTTGCCACCACCTGCGCCCCCGGGATCCGGTGGTCTTTCTGTCTTTCTTGCCGGCAC
ACAAGGTCAGGTGGTCGGAGGACTCGCGGTGTCTCCGCTTGTGGCTTCGGGTCCAG
TGGTACTTATGGCTTCATCGTTCTCTAATGCAACTTTCGAACGGCTTCCGCTTGAGG
ATGAAGGAGGAGAAGGCGGAGGAGGAGAAGTTGGAGAGGGAGGTAGTGGAGCCG
GAGGTGGTGGTCCACCGCAGGCCACGTCGGCATCTTCACCACCGTCTGGAGCTGGT
CAAGGACAGTTAAGAGGTAACATGAGTGGTTATGATCAGTTTGCCGGTGATCCTCA
TGTGCTTGGTGGGAGCTCNGCCCTCCA GCC
Camelina Sob3 ORF 737 bp (SEQ ID NO: 5; reverse coding sequence):
ATG ATGAATCTGACTCCAACAAGGATCCGGGTTCCGACCCGGTTACCTCGAGTTCA
AACTCCTGGGAAGCGTCCACGTGGGCGTCCTCCGGGATCTAAGAACAAGCCGAAGC
CACCGGTGATAGTGACAAGAGATAGCCCCAACGTGCTTAGATCTCATGTTCTTGAA
ATCTCATCTGGAGCCGACATAATTGAGTGCGTTAACACTTACGCTCGCCGGAGAGG
GAAAGGTGTCTCCATTCTCAGTGGTAACGGCACGGTAGCTAACGTCAGCATCCGTC
AGCCGGCAACGGCTCATGCGACTAATGGTGGAGCCGGAGGTGTTGTTTCTTTACAT
GGAAGGTTTGAGGTGCTTTCCATCACTGGTACGGTGTTGCCACCACCTGCGCCCCCG
GGATCCGGTGGTCTTTCTGTCTTTCTTGCCGGCACACAAGGTCAGGTGGTCGGAGGA
CTCGCGGTGTCTCCGCTTGTGGCTTCGGGTCCAGTGGTACTTATGGCTTCATCGTTCT
CTAATGCAACTTTCGAACGGCTTCCGCTTGAGGATGAAGGAGGAGAAGGCGGAGGA
GGAGAAGTTGGAGAGGGAGGTAGTGGAGCCGGAGGTGGTGGTCCACCGCAGGCCA
CGTCGGCATCTTCACCACCGTCTGGAGCTGGTCAAGGACAGTTAAGAGGTAACATG
AGTGGTTATGATCAGTTTGCCGGTGATCCTCATGTGCTTGGTGGGAGCTCNGCCCTC
CA GCC
Camelina Sob3 amino acid sequence (SEQ ID NO: 6):
MMNLTPTRIRVPTRLPRVQTP GKRPRGRPPGSKNK PKPPVIVTRDSPNV LRSHVLEISSG
ADIIECVNTYARRRGKGVSILSGNGTVANVSIRQPATAHATNGGAGGVVSLHGRFEVLS
ITGTVLPPPAPPGSGGLSVFLAGTQGQVVGGLAVSPLVASGPVVLMASSFSNATFE RLPL
EDEGGEGGGGEVGEGGSGAGGGGPPQATSASSPPSGAGQGQLRGNMSGYDQFAGDPH
VLGGSSALQ*
[0077] According to additional aspects, Camelina AHL family polypeptides are provided that have at least one AT-hook motif/domain and a PPC domain (including c-terminal hydrophobic domain) (see above underlined exemplary AT-hook and PPC sequences in the Camelina Esc amino acid sequence (SEQ ID NO:3) and the Camelina Sob3 amino acid sequence (SEQ ID NO:6)), and wherein mutations of the AT hook domain confer a dominant negative phenotype as disclosed herein in the exemplary context of Arabidopsis thaliana AHL genes (Clade II and/or Clade I).
[0078] Particular aspects, therefore, relate to manipulation of the AT-hook domain in Camelina AHL polypeptides/AHL genes, including manipulation of the AT-hook domain (e.g., AT-hook domain mutants and modifications including but not limited to nonsense, missence, deletions, substitutions, muteins, fusions, etc.) in novel sequences SEQ ID NOS:1-6, which have substantial utility for modulation of cell growth in plants. Additional aspects relate to modified plants comprising Camelina derived AHL genes and gene products, and modified versions thereof.
[0079] According to yet further aspects, AHL family polypeptides of other plants, including but not limited to Oryza sativa (Rice); Sorghum bicolor (sorghum); and Zea mays (maize), Brassica rapa, Vitis vinifera, are provided that have at least one AT-hook motif/domain and a PPC domain, and wherein mutations of the at least one AT hook domain confer a dominant negative phenotype as disclosed herein in the exemplary context of Arabidopsis thaliana AHL genes (Clade II and/or Clade I) (see Tables 1 and 2 below).
[0000]
TABLE 1
SOB3 and ESC Homologous Genes in Crops: Oryza sativa (Rice); Sorghum
bicolo r (sorghum); and Zea mays (maize).
Oryza sativa (Rice)
Coding Sequence
Protein Sequence
Os02g0713700
NM_001054449.2
GI:297599833
NP_001047914.1
GI:115448269
SEQ ID NO: 63
SEQ ID NO: 64
Os06g0326900
NM_001187833.1
GI:297724796
NP_001174762.1
GI:297724797
SEQ ID NO: 65
SEQ ID NO: 66
Os02g0448000
NM_001053289.2
GI:297599146
NP_001046754.1
GI:115445949
SEQ ID NO:67
SEQ ID NO:68
Sorghum bicolor (sorghum)
Coding Sequence
Protein Sequence
XM_002438296
XM_002438296.1
GI:242095701
XP_002438341.1
GI:242095702
SEQ ID NO: 69
SEQ ID NO: 70
XM_002452609
XM_002452609.1
GI:242062729
XP_002452654.1
GI:242062730
SEQ ID NO: 71
SEQ ID NO: 72
Zea mays (maize)
Coding Sequence
Protein Sequence
NM_001157768
NM_001157768.1
GI:226502633
NP_001151240.1
GI:226502634
SEQ ID NO: 73
SEQ ID NO: 74
[0000]
TABLE 2
Arabidopsis thaliana AHL family member nucleic acid and protein
sequences.
DNA
Protein
AHL
ATG
Accession
Accession
Number
Number
Number
GI Number
Number
GI Number
AHL1
AT4G12080
NM_117278.3
GI:30682016
NP_192945.2
GI:22328578
SEQ ID NO: 13
SEQ ID NO: 14
AHL2
AT4G22770
NM_118406.3
GI:42567041
NP_194008.1
GI:15235790
SEQ ID NO: 15
SEQ ID NO: 16
AHL3
AT4G25320
BT003408.1
GI:28059576
AAO30071.1
GI:28059577
SEQ ID NO: 17
SEQ ID NO: 18
AHL4
AT5G51590
NM_124538.3
GI:42568466
NP_1999721
GI:15242131
SEQ ID NO: 19
SEQ ID NO: 20
AHL5
AT1G63470
NM_105026.3
GI:186492770
NP_176536.2
GI:30696854
SEQ ID NO: 21
SEQ ID NO: 22
AHL6
AT5G62260
NM_125620.2
GI:79544829
NP_201032.2
GI:79544830
SEQ ID NO: 23
SEQ ID NO: 24
AHL7
AT4G00200
NM_116237.3
GI:145339838
NP_191931.2
GI:145339839
SEQ ID NO: 25
SEQ ID NO: 26
AHL8
AT5G46640
BT015755.1
GI:52627130
AAU84692.1
GI:52627131
SEQ ID NO: 27
SEQ ID NO: 28
AHL9
AT2G45850
AY114678.1
GI:21387186
AAM47997.1
GI:21387187
SEQ ID NO: 29
SEQ ID NO: 30
AHL10
AT2G33620
NM_001124965.1
GI:186505051
NP_001118437.1
GI:186505052
SEQ ID NO: 31
SEQ ID NO: 32
AHL11
AT3G61310
BT008837.1
GI:31711839
AAP68276.1
GI:31711840
SEQ ID NO: 33
SEQ ID NO: 34
AHL12
AT1G63480
AY096576.1
GI:20466008
AAM20226.1
GI:20466009
SEQ ID NO: 35
SEQ ID NO: 36
AHL13
AT4G17950
AY081495.1
GI:20148332
AAM10057.1
GI:20148333
SEQ ID NO: 37
SEQ ID NO: 38
AHL14
AT3G04590
NM_180181.3
GI:79596509
NP 850512.2
GI:79596510
SEQ ID NO: 39
SEQ ID NO: 40
AHL15
AT3G55560
BT024777.1
GI:89001050
ABD59115.1
GI:89001051
SEQ ID NO: 41
SEQ ID NO: 42
AHL16
AT2G42940
BT010995.1
GI:38604059
AAR24773.1
GI:38604060
SEQ ID NO: 42
SEQ ID NO: 42
AHL17
AT5G49700
NM_124348.1
GI:18423057
NP_199781.1
GI:15240535
SEQ ID NO: 43
SEQ ID NO: 44
AHL18
AT3G60870
NM_115951.1
GI:18411756
NP_191646.1
GI:15232970
SEQ ID NO: 45
SEQ ID NO: 46
AHL19
AT3G04570
BT005882.1
GI:29028875
AAO64817.1
GI:29028876
SEQ ID NO: 47
SEQ ID NO: 48
AHL20
AT4G14465
NM_111328.2
GI:30679174
NP_566232.1
GI:18396925
SEQ ID NO: 49
SEQ ID NO: 50
AHL21
AT2G35270
NM_129079.1
GI:18403788
NP_181070.1
GI:15226945
SEQ ID NO: 51
SEQ ID NO: 52
AHL22
AT2G45430
BT020250.1
GI:56121925
AAV74244.1
GI:56121926
SEQ ID NO: 53
SEQ ID NO: 54
AHL23
AT4G17800
NM_117890.4
GI:42566907
NP_193515.1
GI:15236657
SEQ ID NO: 55
SEQ ID NO: 56
AHL24
AT4G22810
NM_118410.2
GI:30685940
NP_194012.1
GI:15235815
SEQ ID NO: 57
SEQ ID NO: 58
AHL25
AT4G35390
BT014971.1
GI:50198776
AAT70422.1
GI:50198777
SEQ ID NO: 11
SEQ ID NO: 12
AHL26
AT4G12050
NM_117275.3
GI:145340130
NP_192942.1
GI:15234404
SEQ ID NO: 59
SEQ ID NO: 60
AHL27
AT1G20900
BT006460.1
GI:30102699
AAP21268.1
GI:30102700
SEQ ID NO: 7
SEQ ID NO: 8
AHL28
AT1G14490
BT029503.1
GI:119360060
ABL66759.1
GI:119360061
SEQ ID NO: 61
SEQ ID NO: 62
AHL29
AT1G76500
NM_106300.3
GI:145337635
NP_177776.1
GI:15223074
SEQ ID NO: 9
SEQ ID NO: 10
Example 6
Expression of the Atsob3-6 cDNA (and other Similar AHL Mutations) were used to Alter Plant Cell Growth
[0080] Over-expression of Atsob3-6 cDNA in Arabidopsis demonstrates that this allele acts as a dominant-negative allele to enhance hypocotyl elongation in seedlings.
[0081] According to particular aspects, over-expression of this dominant-negative allele were also shown to affect adult growth and development suggesting that these types of alleles can be used for altering plant cell growth in general ( FIG. 2 ).
[0082] According to particular aspects, it is likely that this phenotype is caused by interaction between SOB3 and other members of this protein family such as ESC and those that are co-expressed with these two genes ( FIG. 6 ).
[0083] Co-expression analysis of AHL family members Twenty-five of the 29 Arabidopsis AHL genes are expressed in hypocotyls based on e-northern analysis using Affymetrix ATH1 microarray. However, no corresponding probe sets exist for the other four AHL genes. Coexpressed gene information of AHL members has been retrieved from ATTED-II ( Arabidopsis thaliana trans-factor and cis-element prediction database)(Obayashi et al., 2007; Obayashi et al., 2009). Various AHL members have been identified as components in co-expression networks. With this information we generated a network of AHL members with a correlation of co-expression. ( FIG. 6B ). Gene clustering analysis via the BAR (The Bio-Array Resource for Arabidopsis functional genomics) database based on current publicly available microarray data also suggests that the expression of these AHL gene family members are tightly related with each other ( FIG. 6C ; Toufighi et al., 2005). Therefore, among the 29 AHL genes encoded in Arabidopsis thaliana genome, these members are the best candidates for functional redundancy with SOB3 and ESC in seedling and adult plant development; for example, the subset of AHL genes: AHL19, AHL21, AHL22, AHL23 and AHL6, that locate within the co-expressed network I ( FIG. 6 ), which can be expanded to include AHL1, AHL18 and AHL25 (Fujimoto et al., 2004; Jiang, 2004; Lim et al., 2007; Xiao et al., 2009).
[0084] According to particular aspects, another interaction is with the next closest family member HRC ( FIGS. 6 and 7 ).
[0085] According to additional aspects, Applicants have now shown that SOB3, ESC and HRC can physically interact ( FIGS. 3 and 4 ).
Example 8
Transgenic Camelina Plants Expressing the Atsob3-6 cDNA were shown to have Longer Hypocotyls than the Wild Type Controls
[0086] According to further aspects, Applicants have now shown that transgenic Camelina plants expressing the Atsob3-6 cDNA have longer hypocotyls than the wild type controls for both primary (T1) transformants ( FIG. 8 ) and T2 plants in the next generation ( FIG. 9 ).
Example 9
Camelina Sob3 and Esc Sequences/Proteins have Utility to Modulate Cell Growth in Plants
[0087] According to further aspects, the novel sequences (SEQ ID NOS:1-6) shown in Example 5 above, have substantial utility for modulation of cell growth in plants.
[0088] According to further aspects, manipulation of the AT-hook domain in Camelina AHL genes, including manipulation of the AT-hook domain in the novel sequences (SEQ ID NOS:1-6) shown in Example 5 above, have substantial utility for modulation of cell growth in plants. For example AT-hook domain mutants and modification (e.g., nonsense, missence, deletions, substitutions, muteins, fusions, etc.) of SEQ ID NOS:1-6 have substantial utility for modulation of cell growth in plants.
Example 10
Antibodies are Raised Against Camelina SOB3 and ESC Proteins
[0089] According to further aspects, antibodies are raised against the Camelina SOB3 and ESC proteins using the service from Open Biosystem, Inc®. Due to the high similarity of SOB3 and ESC at the protein level (e.g., over 89%), antibodies are developed specifically against peptides from divergent regions in their C-termini. For SOB3 and ESC, the synthetic peptides ‘RGNMSGYDQFAGDPHL’ and ‘CLGWGAGTPSRPPF’ (including Camelina counterparts) are used, respectively. Antibody specificities can be confirmed using E.coli synthesized recombinant proteins. These gene-specific antibodies are used to confirm, for example, that SOB3 and ESC associate with each other by in vitro pull-down assays.
Example 11
Genetic Manipulation of the AT-Hook Domain in Plant AHL Genes to Modulate Cell Growth
[0090] According to further aspects, non-GM breeding approaches, as widely recognized in the art, are used for manipulation of the AT-hook domain in plant AHL genes to modulate cell growth.
Example 12
Targeted Expression of PPC/DUF Domains in Plant AHL Genes to Modulate Cell Growth
[0091] According to further aspects, targeted expression of PPC/DUF domains in plant AHL genes has utility for modulating plant cell growth. In particular aspects, targeted expression of PPC/DUF domains and including the spacer region between the PPC domain and the AT-hook domain, has utility for modulating plant cell growth.
Example 13
Additional Exemplary AHL Sequences
[0092]
[0000]
Arabidopsis thaliana ESC (ESCAROLA) (ESC) mRNA, complete cds
(SEQ ID NO: 7):
GGACCAAAAATTTATTGCAGAGTCGCACATGAATCTCAAGCTTCTCTCTCCTTTTTTT
CCCATAGCACATCAGAATCGCTAAATACGACTCCTATGCAAAGAAGAAGCTACTTC
TTTCTCTTGCCCTAATTAATCTACCTAACTAGGGTTTCCTCTTACCTTTCATGAGAGA
GATCATTTAACATAAGTCACCTTTTTTATATCTTTTGCTTCGTCTTTAATTTAGTTCTG
TTCTTGGTCTGTTTCTATATTTTGTCGGCTTGCGTAACCGATCACACCTTAATGCTTT
AGCTATTGTTTCCTCAAAATCATGAGTTTTGACTTCTCGATCTGAGTTTTCTTTTTCT
CTCTTTACGCTCTTCTTCACCTAGCTACCAATATATGAACGAGCAGGATCAAGAATC
GAGAAATTGATTTGAGCTGGCGAATAAGCAGTGGTGGGATAGGGAATTAGTAGATG
CGGCGGCGATGGAAGGCGGTTACGAGCAAGGCGGTGGAGCTTCTAGATACTTCCAT
AACCTCTTTAGACCGGAGATTCACCACCAACAGCTTCAACCGCAGGGCGGGATCAA
TCTTATCGACCAGCATCATCATCAGCACCAGCAACATCAACAACAACAACAACCGT
CGGATGATTCAAGAGAATCTGACCATTCAAACAAAGATCATCATCAACAGGGTCGA
CCCGATTCAGACCCGAATACATCAAGCTCAGCACCGGGAAAACGTCCACGTGGACG
TCCACCAGGATCTAAGAACAAAGCCAAGCCACCGATCATAGTAACTCGTGATAGCC
CCAACGCGCTTAGATCTCACGTTCTTGAAGTATCTCCTGGAGCTGACATAGTTGAGA
GTGTTTCCACGTACGCTAGGAGGAGAGGGAGAGGCGTCTCCGTTTTAGGAGGAAAC
GGCACCGTATCTAACGTCACTCTCCGTCAGCCAGTCACTCCTGGAAATGGCGGTGGT
GTGTCCGGAGGAGGAGGAGTTGTGACTTTACATGGAAGGTTTGAGATTCTTTCGCTA
ACGGGGACTGTTTTGCCACCTCCTGCACCGCCTGGTGCCGGTGGTTTGTCTATATTTT
TAGCCGGAGGGCAAGGTCAGGTGGTCGGAGGAAGCGTTGTGGCTCCCCTTATTGCA
TCAGCTCCGGTTATACTAATGGCGGCTTCGTTCTCAAATGCGGTTTTCGAGAGACTA
CCGATTGAGGAGGAGGAAGAAGAAGGTGGTGGTGGCGGAGGAGGAGGAGGAGGA
GGGCCACCGCAGATGCAACAAGCTCCATCAGCATCTCCGCCGTCTGGAGTGACCGG
TCAGGGACAGTTAGGAGGTAATGTGGGTGGTTATGGGTTTTCTGGTGATCCTCATTT
GCTTGGATGGGGAGCTGGAACACCTTCAAGACCACCTTTTTAATTGAATTTTAATGT
CCGGAAATTTATGTGTTTTTATCATCTTGTGGAGTCGTCTTTCCTTTGGGATATTTGG
TGTTTAATGTTTAGTTGATATGCATATTTTGGTTTCTCGTG
Arabidopsis thaliana ESC putative protein (SEQ ID NO: 8):
MEGGYEQGGGASRYFHNLFRPEIHHQQLQPQGGINLIDQHHHQHQQHQQQQQPSDDSR
ESDHSNKDHHQQGRPDSDPNTSSSAPGKRPRGRPPGSKNKAKPPIIVTRDSPNALRSHVL
EVSPGADIVESVSTYARRRGRGVSVLGGNGTVSNVTLRQPVTPGNGGGVSGGGGVVTL
HGRFEILSLTGTVLPPPAPPGAGGLSIFLAGGQGQVVGGSVVAPLIASAPVILMAASFSN
AVFERLPIEEEEEEGGGGGGGGGGGPPQMQQAPSASPPSGVTGQGQLGGNVGGYGFSG
DPHLLGWGAGTPSRPPF
Arabidopsis thaliana DNA-binding family protein (AT1G76500) mRNA,
complete cds (SEQ ID NO: 9):
CTGCCATGGACGGTGGTTACGATCAATCCGGAGGAGCTTCTAGATACTTTCACAACC
TCTTCAGGCCTGAGCTTCATCACCAGCTTCAACCTCAGCCTCAACTTCACCCTTTGCC
TCAGCCTCAGCCTCAACCTCAGCCTCAGCAGCAGAATTCAGATGATGAATCTGACTC
CAACAAGGATCCGGGTTCCGACCCAGTTACCTCTGGTTCAACCGGGAAACGTCCAC
GTGGACGTCCTCCGGGATCCAAGAACAAGCCGAAGCCACCGGTGATAGTGACTAGA
GATAGCCCCAACGTGCTTAGATCTCATGTTCTTGAAGTCTCATCTGGAGCCGACATA
GTCGAGAGCGTTACCACTTACGCTCGCAGGAGAGGAAGAGGAGTCTCCATTCTCAG
TGGTAACGGCACGGTGGCTAACGTCAGTCTCCGGCAGCCGGCAACGACAGCGGCTC
ATGGGGCAAATGGTGGAACCGGAGGTGTTGTGGCTCTACATGGAAGGTTTGAGATA
CTTTCCCTCACAGGTACGGTGTTGCCGCCCCCTGCGCCGCCAGGATCCGGTGGTCTT
TCTATCTTTCTTTCCGGCGTTCAAGGTCAGGTGATTGGAGGAAACGTGGTGGCTCCG
CTTGTGGCTTCGGGTCCAGTGATACTAATGGCTGCATCGTTCTCTAATGCAACTTTC
GAAAGGCTTCCCCTTGAAGATGAAGGAGGAGAAGGTGGAGAGGGAGGAGAAGTTG
GAGAGGGAGGAGGAGGAGAAGGTGGTCCACCGCCGGCCACGTCATCATCACCACC
ATCTGGAGCCGGTCAAGGACAGTTAAGAGGTAACATGAGTGGTTATGATCAGTTTG
CCGGTGATCCTCATTTGCTTGGTTGGGGAGCCGCAGCCGCAGCCGCACCACCAAGA
CCAGCCTTTTAGAATTGAAAATTATGTCCGTAACATAGCTGTAACCAAATTTCATTT
CTCAAAATTAAAAGAAAAAAAAAATCATCTTCATTGTTTGGGGATCGTTTGGTTTTT
AATTTAGTTGATCATATATG
Arabidopsis thaliana Sob3 putative protein (SEQ ID NO: 10)
MDGGYDQSGGASRYFHNLFRPELHHQLQPQPQLHPLPQPQPQPQPQQQNSDDESDSNK
DPGSDPVTSGSTGKRPRGRPPGSKNKPKPPVIVTRDSPNVLRSHVLEVSSGADIVESVTT
YARRRGRGVSILSGNGTVANVSLRQPATTAAHGANGGTGGVVALHGRFEILSLTGTVL
PPPAPPGSGGLSIFLSGVQGQVIGGNVVAPLVASGPVILMAASFSNATFERLPLEDEGGE
GGEGGEVGEGGGGEGGPPPATSSSPPSGAGQGQLRGNMSGYDQFAGDPHLLGWGAAA
AAAPPRPAF
Camelina ESC (SEQ ID NO: 1)
AATTCNGGANTTTAANTTCGATTAAAATAGTGGTCTTGAAGGTGTTCCAGCTCCCCA
TCCAAGCAAATGAGGATCACCAGAAAACCCATAACCACCCACATTACCTCCTAACT
GTCCCTGACCGGTCACGCCTGACGGAGGCGATGCTGAGGGAGCTTGCTGCATCTGC
GGTGGTCCTCCTCCTCCCCCTCCGCCAGCACCAGCACCTTCTTCTTCTTCCTCTTCCA
TTGGTAGTCTCTCGAAAACCGCATTTGAGAACGAAGCAGCCATTAGTATAACTGGA
GCTGATGCAATAAGCGGAGCCACCACGCTTCCTCCAACAACCTGACCTTGCCCACC
GGCTAGAAATATTGACAAACCACCTGCACCAGGCGGCGCAGGAGGTGGCAAAACA
GTCCCCGTTAGTGAAAGAATCTCAAATCTTCCATGTAAAGTCACAACTCCTCCTCCT
CCTCCTCCGGACACACCACCACCGTTTCCGGGAGTGACTGGCTGACGGAGAGTGAC
GTTAGAAACGGTGCCGTTCCCTCCTAAAACGGAGACGCCTCTCCCTCTCCGCCTAGC
GTAAGTGGAAACACTCTCAACTATATCAGCTCCGGGAGATACTTCAAGGACGTGAG
ATCTAAGCGCGTTGGGGCTGTCACGGGTTACTATGATCGGTGGCTTTGCTTTGTTCT
TAGATCCTGGCGGACGTCCACGTGGACGTTTCCCGGGTGTTGAGCTTGATGTATTCG
GGTCTGAATCGGGGTCGACCCTGTTGATGATGATCCTTGTTTGAGTGTTCAGATTCT
CTTGAATCATCCGACGGTKGCTGTTGTTGTTGTTGTTGTTGCTGCTGATGCTGATGAT
GATGCTGGTCAATAAGATTGATTCCACCCTGCGGTTGAAGGTGCTGGTGGTGAATCT
CCGGTCTGAAGAGGTTTAGAAAGATCTAGAAGTCCACCGCTNTA
Camelina Esc ORF (SEQ ID NO: 2)
ATGATTCAAGAGAATCTGAACACTCAAACAAGGATCATCATCAACAGGGTCGACCC
CGATTCAGACCCGAATACATCAAGCTCAACACCCGGGAAACGTCCACGTGGACGTC
CGCCAGGATCTAAGAACAAAGCAAAGCCACCGATCATAGTAACCCGTGACAGCCCC
AACGCGCTTAGATCTCACGTCCTTGAAGTATCTCCCGGAGCTGATATAGTTGAGAGT
GTTTCCACTTACGCTAGGCGGAGAGGGAGAGGCGTCTCCGTTTTAGGAGGGAACGG
CACCGTTTCTAACGTCACTCTCCGTCAGCCAGTCACTCCCGGAAACGGTGGTGGTGT
GTCCGGAGGAGGAGGAGGAGGAGTTGTGACTTTACATGGAAGATTTGAGATTCTTT
CACTAACGGGGACTGTTTTGCCACCTCCTGCGCCGCCTGGTGCAGGTGGTTTGTCAA
TATTTCTAGCCGGTGGGCAAGGTCAGGTTGTTGGAGGAAGCGTGGTGGCTCCGCTT
ATTGCATCAGCTCCAGTTATACTAATGGCTGCTTCGTTCTCAAATGCGGTTTTCGAG
AGACTACCAATGGAAGAGGAAGAAGAAGAAGGTGCTGGTGCTGGCGGAGGGGGAG
GAGGAGGACCACCGCAGATGCAGCAAGCTCCCTCAGCATCGCCTCCGTCAGGCGTG
ACCGGTCAGGGACAGTTAGGAGGTAATGTGGGTGGTTATGGGTTTTCTGGTGATCCT
CATTTGCTTGGATGGGGAGCTGGAACACCTTCAAGACCACTATTTTAA
Camelina putative Esc amino acid sequence (SEQ ID NO: 3)
MIQENLNTQTRIIINRVDPDSDPNTSSSTPGKRPRGRPPGSKNKAKPPIIVTRDSPNALRSH
VLEVSPGADIVESVSTYARRRGRGVSVLGGNGTVSNVTLRQPVTPGNGGGVSGGGGGG
VVTLHGRFEILSLTGTVLPPPAPPGAGGLSIFLAGGQGQVVGGSVVAPLIASAPVILMAA
SFSNAVFERLPMEEEEEEGAGAGGGGGGGPPQMQQAPSASPPSGVTGQGQLGGNVGG
YGFSGDPHLLGWGAGTPSRPLF
Camelina sob3 (SEQ ID NO: 4)
GGCTGGAGGGCNGAGCTCCCACCAAGCACATGAGGATCACCGGCAAACTGATCATA
ACCACTCATGTTACCTCTTAACTGTCCTTGACCAGCTCCAGACGGTGGTGAAGATGC
CGACGTGGCCTGCGGTGGACCACCACCTCCGGCTCCACTACCTCCCTCTCCAACTTC
TCCTCCTCCGCCTTCTCCTCCTTCATCCTCAAGCGGAAGCCGTTCGAAAGTTGCATTA
GAGAACGATGAAGCCATAAGTACCACTGGACCCGAAGCCACAAGCGGAGACACCG
CGAGTCCTCCGACCACCTGACCTTGTGTGCCGGCAAGAAAGACAGAAAGACCACCG
GATCCCGGGGGCGCAGGTGGTGGCAACACCGTACCAGTGATGGAAAGCACCTCAA
ACCTTCCATGTAAAGAAACAACACCTCCGGCTCCACCATTAGTCGCATGAGCCGTTG
CCGGCTGACGGATGCTGACGTTAGCTACCGTGCCGTTACCACTGAGAATGGAGACA
CCTTTCCCTCTCCGGCGAGCGTAAGTGTTAACGCACTCAATTATGTCGGCTCCAGAT
GAGATTTCAAGAACATGAGATCTAAGCACGTTGGGGCTATCTCTTGTCACTATCACC
GGTGGCTTCGGCTTGTTCTTAGATCCCGGAGGACGCCCACGTGGACGCTTCCCAGGA
GTTTGAACTCGAGGTAACCGGGTCGGAACCCGGATCCTTGTTGGAGTCAGATTCATC
ATCTGATTGTTGTTGCTGAGGCTCAGGTTGAGGTTGAGGTTGAGGCAGAGGGTGGA
GATGAGGCTGARGTTGAAGTTGGCGATGAAGGTCAGGTCTGAAAGAGGTTGTGAAA
GTATCCACNTTCNTGNCCGCNNTNTG
Camelina Sob3 ORF (SEQ ID NO: 5)
GGCTGGAGGGCNGAGCTCCCACCAAGCACATGAGGATCACCGGCAAACTGATCATA
ACCACTCATGTTACCTCTTAACTGTCCTTGACCAGCTCCAGACGGTGGTGAAGATGC
CGACGTGGCCTGCGGTGGACCACCACCTCCGGCTCCACTACCTCCCTCTCCAACTTC
TCCTCCTCCGCCTTCTCCTCCTTCATCCTCAAGCGGAAGCCGTTCGAAAGTTGCATTA
GAGAACGATGAAGCCATAAGTACCACTGGACCCGAAGCCACAAGCGGAGACACCG
CGAGTCCTCCGACCACCOTGACCTTGTGTGCCGGCAAGA AAGACAGAAAGACCACC
GGATCCCGGGGGCGCAGGTGGTGGCAACACCGTACCAGTGATGGAAAGCACCTCA
AACCTTCCATGTAAAGAAACAACACCTCCGGCTCCACCATTAGTCGCATGAGCCGTT
GCCGGCTGACGGATGCTGACGTTAGCTACCGTGCCGTTACCACTGAGAATGGAGAC
ACCTTTCCCTCTCCGGCGAGCGTAAGTGTTAACGCACTCAATTATGTCGGCTCCAGA
TGAGATTTCAAGAACATGAGATCTAAGCACGTTGGGGCTATCTCTTGTCACTATCAC
CGGTGGCTTCGGCTTGTTCTTAGATCCCGGAGGACGCCCACGTGGACGCTTCCCAGG
AGTTTGAACTCGAGGTAACCGGGTCGGAACCCGGATCCTTGTTGGAGTCAGATTCA
TCAT
Camelina Sob3 putative amino acid sequence (SEQ ID NO: 6):
MMNLTPTRIRVPTRLPRVQTPGKRPRGRPPGSKNKPKPPVIVTRDSPNVLRSHVLEISSG
ADIIECVNTYARRRGKGVSILSGNGTVANVSIRQPATAHATNGGAGGVVSLHGRFEVLS
ITGTVLPPPAPPGSGGLSVFLAGTQGQVVGGLAVSPLVASGPVVLMASSFSNATFERLPL
EDEGGEGGGGEVGEGGSGAGGGGPPQATSASSPPSGAGQGQLRGNMSGYDQFAGDPH
VLGGSSALQ
Sob 3 homologue in Brassica rapa sub Pekinese: [mRNA] 1 exon (s)
87-950 864 bp, chain +
(SEQ ID NO: 76):
ATGGACGGTGGTTATGATCAATCCGGTCACTCTAGATACTTCCATAACCTCTTTAGG
CCTGAGCTTCAACACCAGCTTCAGCCACAGCCGCAGCCTCAACCCCAGCCTCAGCCT
CAGCCTCAGCCTCAGTCTGATGATGAATCTGACTCCAACAACAAGTATCCGGGTCA
ACCTGATTCCGACCAGGTTACCTCGGGCTCAACTTCCGGGAAGCGTCCACGTGGAC
GTCCTCCAGGGTCTAAGAACAAGCCGAAGCCACCGGTGATAGTGACAAGAGATAGC
CCCAACGTGCTTAGATCTCATGTTCTTGAAGTCTCATCTGGAGCCGACATAATTGAG
AGCGTCAACAATTATGCTCGCCGGAGAGGGAGAGGTGTCTCCATTCTCAGTGGTAA
CGGCACGGTGGCTAACCTCACTCTCCGGCAGCCGGTGACGACTCATGGGAACAATG
GTGGAACTGAAGCCGGAGCCGGAGGAGTTGTGACTTTACGTGGAAGGTTTGAGATT
CTTTCCATCACTGGTACGGTGCTTCCGCCGCCCGCGCCGCCGGGATGCGGTGGTTTA
TCTATCTTTGTTGCTGGTGAACAAGGTCGGGTGATCGGAGGAAGAGTGGTGGCTCC
CCTTGTGGCTTCTGGTCCAGTGATACTGATGGCTGCATCGTTCTCCAACGCAACTTT
CGAAAGGCTTCCACTTGAAGAGGAGGGAGGTGAAGGTGGGGGAGACGTCGGAGGA
GGAGTTCCACCGCCAGCCACTTCAGAAACAGCGCCGTCTGGAGTCGCTCAGGGAGA
GCTAAGAGTTAATATGAGTGGTTATGATCAGTTTTCCGGCTGGGGAGCCGGAGCCG
CTTCAAGACCATCATTTTAG
Sob 3 homologue in Brassica rapa sub Pekinese: putative amino acid
sequence 1 exon (s) 87-950 287 aa, chain + (SEQ ID NO: 77):
MDGGYDQSGHSRYFHNLFRPELQHQLQPQPQPQPQPQPQPQPQSDDESDSNNKYPGQP
DSDQVTSGSTSGKRPRGRPPGSKNKPKPPVIVTRDSPNVLRSHVLEVSSGADIIESVNNY
ARRRGRGVSILSGNGTVANLTLRQPVTTHGNNGGTEAGAGGVVTLRGRFEILSITGTVL
PPPAPPGCGGLSIFVAGEQGRVIGGRVVAPLVASGPVILMAASFSNATFERLPLEEEGGE
GGGDVGGGVPPPATSETAPSGVAQGELRVNMSGYDQFSGWGAGAASRPSF
Esc homologue in Brassica rapa sub. Pekinese: [mRNA] 1 exon (s)
67-1002 936 bp, chain + (SEQ ID NO: 78):
ATGGAAGGCGGCTACGAGCAAGGCGGTGGAGCTTCTAGGTACTTCCATAACCTCTT
CAGACCAGAGATTCACCACCAACAGCTTCAACAACAAGGCGGGATCAATCTTTTTG
ACCAGCATCATCAACAGCAACAACATCAGCAGCAACAACAACAACAACCGTCAGA
TGATTCAAGAGAATCCGATCACTCAAACAAGGATCATCATCAACCGGGTCTACCCG
ATTCAGACCCGGCTACATCAAGCTCAGCACCTGGGAAACGTCCACGTGGACGTCCA
CCGGGATCTAAGAACAAAGCTAAGCCACCGATCATAGTGACGCGGGACAGCCCCA
ATGCGCTTAGATCTCACGTCCTTGAAGTATCTCCTGGAGCTGACATAGTTGAGTGTG
TGTCCACTTACGCTAGGCGGAGAGGGAGAGGGGTCTCCGTTTTAGGAGGAAACGGC
ACCGTTTCCAACGTCACTCTTCGTCAGCCAGTCACTCCCGGAAATAGCGGTGGTGGA
GCCGGAGGAGGAGTTGTGACTTTACATGGAAGGTTTGAGATTCTTTCGCTAACGGG
AACCGTTTTGCCACCACCTGCACCGCCAGGTGCTGGTGGTTTGTCAATATTTTTATC
CGGAGGGCAAGGTCAGGTGGTTGGGGGAAGCGTTGTGGCTCCGCTTGTTGCATCAG
CTCCGGTTATACTAATGGCTGCTTCCTTCTCAAACGCGGTTTTCGAGAGATTGCCTA
TTGAAGAGGAGGAAGAAAGAGGTGGTGGCGGTGTAGGAGAAGGAGAAGGACCACC
GCAGATGCAGCAAGCTCCATCACCATCTCCGCGGTCGGGGGTGACCGGTCAAGGAC
AGCTAGGAGGTAATGTGGGTGGTTATGGGTTTTCCAGTGATCCTCATTTGCTAGGAT
GGGGAGCTGGTACGCCTTCAAGACCACCTTTTACTTAA
Esc homologue in Brassica rapa sub. Pekinese: putative amino acid
sequence 1 exon (s) 67-1002 311 aa, chain + (SEQ ID NO: 79):
MEGGYEQGGGASRYFHNLFRPEIHHQQLQQQGGINLFDQHHQQQQHQQQQQQQPSDD
SRESDHSNKDHHQPGLPDSDPATSSSAPGKRPRGRPPGSKNKAKPPIIVTRDSPNALRSH
VLEVSPGADIVECVSTYARRRGRGVSVLGGNGTVSNVTLRQPVTPGNSGGGAGGGVVT
LHGRFEILSLTGTVLPPPAPPGAGGLSIFLSGGQGQVVGGSVVAPLVASAPVILMAASFS
NAVFERLPIEEEEERGGGGVGEGEGPPQMQQAPSPSPRSGVTGQGQLGGNVGGYGFSS
DPHLLGWGAGTPSRPPFT
DNA-binding family protein [ Arabidopsis thaliana ] (sob3)
(SEQ ID NO: 10):
MDGGYDQSGGASRYFHNLFRPELHHQLQPQPQLHPLPQPQPQPQPQQQNSDDESDSNK
DPGSDPVTSGSTGKRPRGRPPGSKNKPKPPVIVTRDSPNVLRSHVLEVSSGADIVESVTT
YARRRGRGVSILSGNGTVANVSLRQPATTAAHGANGGTGGVVALHGRFEILSLTGTVL
PPPAPPGSGGLSIFLSGVQGQVIGGNVVAPLVASGPVILMAASFSNATFERLPLEDEGGE
GGEGGEVGEGGGGEGGPPPATSSSPPSGAGQGQLRGNMSGYDQFAGDPHLLGWGAAA
AAAPPRPAF
ESC (ESCAROLA) [ Arabidopsis thaliana ] (SEQ ID NO: 8):
MEGGYEQGGGASRYFHNLFRPEIHHQQLQPQGGINLIDQHHHQHQQHQQQQQPSDDSR
ESDHSNKDHHQQGRPDSDPNTSSSAPGKRPRGRPPGSKNKAKPPIIVTRDSPNALRSHVL
EVSPGADIVESVSTYARRRGRGVSVLGGNGTVSNVTLRQPVTPGNGGGVSGGGGVVTL
HGRFEILSLTGTVLPPPAPPGAGGLSIFLAGGQGQVVGGSVVAPLIASAPVILMAASFSN
AVFERLPIEEEEEEGGGGGGGGGGGPPQMQQAPSASPPSGVTGQGQLGGNVGGYGFSG
DPHLLGWGAGTPSRPPF
PREDICTED: hypothetical protein [ Vitis vinifera ] (SEQ ID NO: 80):
MAGMEQGAGSRYIHQLFRPELQLERTPQQPHQPPQLNDSGDSPENEDRTDPDGSPGAA
TTSSRRPRGRPPGSKNKAKPPIIITRDSPNALRSHVLEISAGADIVESVSNYARRRGRGVCI
LSGGGAVTDVTLRQPAAPSGSVVTLHGRFEILSLTGTALPPPAPPGAGGLTIYLGGGQGQ
VVGGRVVGPLVASGPVLLMAASFANAVYDRLPLEEEEESPVQVQPTASQSSGVTGGGG
QLGDGGNGSTTTAGGGAGAGVPFYNLGPNMGNYPFPGDVFGWNGGATRPPF
PREDICTED: hypothetical protein [ Vitis vinifera ] (SEQ ID NO: 81):
MEGYEPGSGSRYVHQLLGPELHLQRPSSLPQHQATQQPSDSRDESPDDQEQRADTEEA
AAASSGGATTSSNRRPRGRPPGSKNKPKPPIIVTRDSPNALRSHVLEVAAGADVMESVL
NYARRRGRGVCVLSGGGTVMNVTLRQPASPAGSIVTLHGRFEILSLSGTVLPPPAPPSAG
GLSIFLSGGQGQVVGGSVVGPLMASGPVVLMAASFANAVFERLPLEEEEGAVQVQPTA
SQSSGVTGGGAGGQLGDGGGSGGGAGVPIYNMGASMGNFPFPGDLLRWGGSAPRPPF
DNA binding protein, putative [ Ricinus communis ] (SEQ ID NO: 25):
MAGYNNEQSATGTGSRYVHQLLRPELHLQRPSFPSQPSSDSKDNNISPQSKDHNKFSDS
EAAAATSSGSNRRPRGRPAGSKNKPKPPIIVTRDSPNALRSHVLEVSTGSDIMESVSIYAR
KRGRGVCVLSGNGTVANVTLRQPASPAGSVVTLHGRFEILSLSGTVLPPPAPPGAGGLSI
FLSGGQGQVVGGSVVGPLMASGPVVLMAASFANAVFERLPLDEEDGTVPVQSTASQSS
GVTGGGGGAGQLGDGGGGGGAGLFNMGGNVANYPFSGDLFGW GVNAARPPF
Oryza sativa (japonica cultivar-group) (SEQ ID NO: 68):
MAGMDPGGGGAGAGSSRYFHHLLRPQQPSPLSPLSPTSHVKMEHSKMSPDKSPVGEGD
HAGGSGSGGVGGDHQPSSSAMVPVEGGSGSAGGSGSGGPTRRPRGRPPGSKNKPKPPII
VTRDSPNALHSHVLEVAGGADVVDCVAEYARRRGRGVCVLSGGGAVVNVALRQPGA
SPPGSMVATLRGRFEILSLTGTVLPPPAPPGASGLTVFLSGGQGQVIGGSVVGPLVAAGP
VVLMAASFANAVYERLPLEGEEEEVAAPAAGGEAQDQVAQSAGPPGQQPAASQSSGV
TGGDGTGGAGGMSLYNLAGNVGGYQLPGDNFGGWSGAGAGGVRPPF
Example 14
T3 Generation Camelina Seedlings Over-Expressing Atsob3-6 Emerged from this Deep Planting Whereas no Wild Type Plants Did
[0093] FIG. 10 shows T3 generation Camelina seedlings over-expressing Atsob3-6 (right) compared to wild type syblings (left) after being planted on 1 cm of moist Palouse silt-loam and then covered with 8 cm of dry Palouse silt loam. Ten seedlings were placed in each pot. 30 to 50% of the transgenic seedlings emerged from this deep planting whereas no wild type plants did. After this experiment was completed, it was determined that both pots experienced 100% germination. Experiment has been repeated three times.
Example 15
The Weight of 100 T4 Generation Camelina Seeds Over-Expressing Atsob3-6 (Right) was Determined to be Heavier Compared to Controls
[0094] FIG. 11 shows that the weight of 100 T4 generation Camelina seeds over-expressing Atsob3-6 (right) is heavier when compared to a transgenic line expressing the empty-vector (left). The transformant line (right) also yields seedlings with longer hypocotyls than empty-vector control line.
Example 16
The Weight of 100 Homozygous Arabidopsis sob3-6 Mutant Seeds (Left) was Determined to be Heavier when Compared to Wild-Type Control
[0095] FIG. 12 shows that the weight of 100 homozygous Arabidopsis sob3-6 mutant seeds (left) is heavier when compared to a wild-type control (right). Raw values are presented above the bars along with ±SEM.
Example 17
The Weight of 100 T3 Generation Transgenic Arabidopsis Seeds Over-Expressing Atsob3-6 was Determined to be Heavier when Compared to the Wild Type, and Confers a Longer Hypocotyl than the Wild-Type
[0096] FIG. 13 shows the weight of 100 T3 generation transgenic Arabidopsis seeds over-expressing Atsob3-6 compared to the wild type. Transformant-2 (far-right) is heavier when compared to the wild type (far-left) and Transformant-1 (center). Transformant-1 confers a hypocotyl phenotype that is the same as the wild type. Transformant-2 confers a longer hypocotyl than the wild-type. Raw values are presented above the bars along with ±SEM.
Example 18
The esc-11 Mutation also Conferred a Long Hypocotyl Phenotype in Arabidopsis T1 Transgenic Seedlings
[0097] FIG. 14 shows that the esc-11 mutation also confers a long hypocotyl phenotype in Arabidopsis T1 transgenic seedlings. The esc-11 allele was created with the same mutation as sob3-6 using site-directed-mutagenesis. Wild-type (Col-0) were transformed with an empty vector control (far-left), the wild-type copy of ESC (ESCox1 and ESCox2) or with the esc-11 allele (esc-11ox1 to esc-11ox7). The ESCox and esc-11ox alleles were driven by the CaMV35S promoter. Scale bar=5 mm.
Example 19
Overexpression of the SOB3 PPC Domain and the Linker Region between the PPC Domain and the AT-Hook was Sufficient to Confer a Long Hypocotyl Phenotype in T1 Transgenic Arabidopsis Seedlings
[0098] FIG. 15 shows that the overexpression of the SOB3 PPC domain and the linker region between the PPC domain and the AT-hook is sufficient to confer a long hypocotyl phenotype in T1 transgenic Arabidopsis seedlings. A wild-type (Col-0) seedling transformed with an empty vector control is shown on the left. A wild-type T1 seedling transformed with the linker region and the PPC domain driven by the CaMV35S promoter is shown on the right. Scale bar=2 mm. | Provided are methods for generating modified plants, seedlings or seeds, comprising introducing into, or engineering in a plant cell, a nucleic acid encoding a mutant AHL protein having a mutation of the AT hook domain that confers a dominant negative phenotype as disclosed herein. Nucleic acids encoding a polypeptide comprising SEQ ID NO:3, SEQ ID NO:6, a polypeptide having at least 93% or at least 95% sequence identity with SEQ ID NO:3, or a polypeptide having at least 75% or at least 80% sequence identity with SEQ ID NO:6 are provided, along with such polypeptides having a mutation of the AT hook domain that confers a dominant negative phenotype as disclosed herein. In particular aspects, the polypeptide lacks the AT hook domain thereof. In certain aspects, the polypeptide comprises an intact or functional PPC domain, and preferably additionally comprises the linker region between the PPC domain and the AT-hook domain. | 2 |
BACKGROUND OF THE INVENTION
1. Technical Field of the Invention
The present invention relates to a lag correction technology of audio samples in which sample mismatching between nodes in a ring audio network system is corrected based on the positional relationship of the nodes.
The present invention also relates to a technology for a ring audio network system in which transmission delay times in the system are taken into consideration and the output times of audio signals from nodes are corrected, thereby correcting the phase difference of all the nodes in the system.
2. Description of the Related Art
Conventional technologies for audio signal communication in an audio network system used for PA such as plays and concerts, music production, and private broadcasting include CobraNet™ described in Non-Patent Reference 1, SuperMAC (registered trademark) described in Non-Patent Reference 2, and EtherSound (registered trademark) described in Non-Patent Reference 3. Any of them is a technology for transmitting audio signals over the Ethernet.
Conventional technologies used in a telephone line network include a ring communication network such as FDDI/TokenRing. In this scheme, a token (i.e., the right to transmit data) circulates through nodes connected in a ring so that only a node which obtains the token is permitted to transmit data.
One can consider an audio signal (audio sample data) transmission scheme using the conventional ring communication network. FIG. 13 illustrates an example of a ring audio network system. A signal circulates through nodes reciprocally along the nodes in the order of node 1301 node 1302 node 1303 node 1302 node 1301 . FIG. 14 illustrates another example of the same ring audio network system. In this example, nodes 1401 to 1406 are physically connected in a ring in the named order. A packet transmitted from the master node 1401 circulates once in one sampling cycle (or time) in the order of 1401 1402 1403 1404 1405 1406 . A storage region of audio sample data of a plurality of channels (Ch) is allocated in the packet and each node transmits data by loading it into a storage region of a suitable channel in the packet.
However, in the system in which data is transmitted in a ring as described above, sample data of the same sampling cycle in which corresponding sample data is stored in the circulated packet by the node 1404 is extracted from the node 1406 , while sample data of a different sampling cycle is extracted from the node 1403 . This is because, when the sample data stored in the node 1404 reaches the master node 1401 , the sample data is incorporated into a packet that circulates in the next sampling cycle, and the node 1403 then receives the packet. By such a manner, there is caused sample time mismatching between nodes in a conventional ring audio network system. Usually, such sample mismatching causes almost no problem. However, a variety of professional audio devices may not permit such sample mismatching.
Further in the conventional system in which data is transmitted in a ring as described above, it is difficult to accurately match output timings of audio signals of all nodes of the system. Particularly, as long as the system uses transmission lines, the system suffers from delay in signal transmission through the transmission lines. Processing in each node also causes a delay. Usually, such a small delay causes almost no problem. However, a variety of professional audio devices may not permit even such a small time delay, and there may be a desire to eliminate even the phase difference of audio signals output from all nodes. For example, in order to strictly design and set up a line array speaker system, it may be necessary to take into consideration even such a small delay.
SUMMARY OF THE INVENTION
It is a first object of the present invention to provide a sample mismatching correction technology for a ring audio network system in which, when audio sample data is transmitted while circulating a packet through nodes, sample mismatching is corrected so that signals input at an absolute time are output from all the nodes in the same sampling cycle (or time), regardless of the positional relationship of the nodes.
It is a second object of the present invention to provide a delay correction technology which ensures that a ring audio network system can output audio signals without any phase difference of nodes by taking into consideration a very small delay such as a delay on a transmission line when performing transmission of audio sample data while circulating a packet through the nodes.
In order to achieve the first object, the invention provides an audio network system that connects a plurality of nodes in a ring so as to allow loop transmission of data and that performs data transmission in one direction through the ring of the nodes to perform communication between any ones of the plurality of the nodes, wherein one of the plurality of the nodes is a master node and the other nodes are slave nodes, wherein the master node transmits a packet of frame data regularly every sampling cycle, such that the packet circulates through the plurality of the nodes connected in the ring during the sampling cycle, wherein the packet is provided with a plurality of regions for containing audio sample data in correspondence to a plurality of channels, and wherein each of the nodes includes: a reading part that reads audio sample data from a particular region of the packet, which corresponds to a particular channel allocated to the node, the audio sample data being written into the particular region by another node; a storage part that stores the read audio sample data of the channel allocated to the node, wherein the storage part stores a current one of the audio sample data read in a current sampling cycle and a previous one of the audio sample data read in one sampling cycle ago; an acquiring part that acquires positional information which indicates whether said another node which writes the audio sample data of the allocated channel into the packet is located upstream or downstream of the node along a stream of the packet which is transmitted from the master node, then flows through the nodes and returns to the master node; and an output part that outputs the audio sample data of the allocated channel stored in the storage part, wherein the output part outputs the previous one of the audio sample data of the allocated channel from the storage part if said another node which writes the audio sample data of the allocated channel into the packet is located upstream of the node, and the output part outputs the current one of the audio sample data of the allocated channel from the storage part if said another node is located downstream of the node.
In an extended form, the storage part stores n+1 number of the audio sample data ranging from a current one of the audio sample data read in a current sampling cycle to previous ones of the audio sample data read in 1 through n sampling cycles ago, where “n” is an integer equal to or greater than 1. The output part outputs a previous one of the audio sample data of the allocated channel which has been stored n sampling cycles ago if said another node which writes the audio sample data of the allocated channel into the packet is located upstream of the node, and the output part outputs another previous one of the audio sample data of the allocated channel which has been stored n−1 sampling cycles ago if said another node is located downstream of the node.
In order to achieve the second object, the invention provides an audio network system that connects a plurality of nodes in a ring so as to allow loop transmission of data and that performs data transmission in one direction through the plurality of the nodes to perform communication between any ones of the plurality of the nodes, wherein one of the plurality of the nodes is a master node and the other nodes are slave nodes, wherein the master node transmits a packet of frame data regularly every sampling cycle, such that the packet circulates through the plurality of the nodes connected in the ring during the sampling cycle, wherein the packet is provided with a plurality of regions for containing audio sample data in correspondence to a plurality of channels allocated to the respective nodes for performing transmission of the audio sample data between the respective nodes, wherein each of the nodes calculates a correction time that elapses until the master node receives the packet after the node receives the packet, and wherein, when each of the nodes outputs the audio sample data of the allocated channel to an external device, the node outputs the audio sample data at an output time which is adjusted by the correction time.
In a specific form, the inventive audio network system connects a plurality of nodes in a ring so as to allow loop transmission of data and performs data transmission in one direction through the plurality of the nodes to perform communication between any ones of the plurality of the nodes, wherein one of the plurality of the nodes is a master node and the other nodes are slave nodes, wherein the ring of the nodes is constructed such that a first part of the plurality of the slave nodes are connected in chains in a forward direction so that data is transmitted from the master node in the forward direction and the first part of the plurality of the slave nodes are connected in chains in a backward direction so that the data is transmitted from a terminal slave node of the forward direction in the backward direction until the data reaches the master node after the data turns around upon reaching the terminal slave node in the forward direction, and the second part of the plurality of the slave nodes are connected in chains in a backward direction so that data is transmitted from the master node in the backward direction and the second part of the plurality of the slave nodes are connected in chains in a forward direction so that the data is transmitted from a terminal slave node of the backward direction in a forward direction until the data reaches the master node after the data turns around upon reaching the terminal slave node in the backward-direction, wherein the master node transmits a packet of frame data regularly every sampling cycle, such that the packet circulates through the plurality of the nodes connected in the ring during the sampling cycle, wherein the packet is provided with a plurality of regions for containing audio sample data in correspondence to a plurality of channels which are allocated to the respective nodes, wherein the master node includes: an acquiring part that acquires delay information including a total network delay time during which the packet circulates through the ring of the nodes and then returns to the master node, a forward-side delay time that elapses until the packet returns to the master node in the backward direction after being transmitted in the forward direction, and a backward-side delay time that elapses until the packet returns to the master node in the forward direction after being transmitted in the backward direction; and a notifying part that notifies all the slave nodes of the acquired delay information including the total network delay time, forward-side delay time, and backward-side delay time, wherein each of the slave nodes includes: a first calculating part that calculates a reception time difference between a reception time of the packet received in the forward direction and another reception time of the packet received in the backward direction; a second calculating part that calculates a correction time that elapses from a time when the node receives the packet to another time when the master node receives the packet using the notified delay information from the master node and the calculated reception time difference; a reading part that reads the audio sample data from a particular region of the packet which corresponds to the allocated channel; a storage part that stores the read audio sample data of the allocated channel; and an output part that outputs the audio sample data stored in the storage part at a proper output time which is adjusted by the correction time.
According to the first aspect of the invention, it is possible to extract data of the same sampling cycle of all channels from every node in a synchronous ring audio network, without depending on the positional relationship of nodes to which data is input and nodes from which data is output.
According to the second aspect of the invention, even in an audio network having a transmission delay, it is possible to output audio signals from respective nodes at the same time and to output in-phase audio signals from all the nodes. Thus, the invention is suitable for application to an audio system (for example, a line array speaker system) in which the phase difference between output audio signals of nodes is seriously considered.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a module configuration diagram of an audio network system according to the present invention.
FIG. 2 is a hardware configuration diagram of each node.
FIG. 3 is a flow chart of an audio data input routine.
FIG. 4 is a flow chart of an audio data output routine.
FIG. 5 is a flow chart of a delay time calculation routine for a master node.
FIG. 6 is a flow chart of a delay time calculation routine for a slave node.
FIG. 7 is a flow chart of an audio data output routine for a slave node.
FIG. 8 illustrates a sample mismatching correction method.
FIG. 9 illustrates the definitions of delay and transmission/reception times.
FIGS. 10 a , 10 b and 10 c illustrate delay times calculated by a master node.
FIG. 11 illustrates delay times calculated by a slave node.
FIG. 12 illustrates an example of correction time calculation for each node.
FIG. 13 illustrates an example of a ring audio network system.
FIG. 14 illustrates another example of the ring audio network system.
FIGS. 15 a and 15 b illustrate an example occurrence of mismatching of samples.
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will now be described with reference to the drawings.
FIG. 1 illustrates a module configuration of an audio network system according to the invention. Reference numerals “ 101 ” to “ 104 ” denote four nodes that are connected so as to circulate a packet 150 in a ring as shown by a dotted line 151 . A microphone 112 is connected to the node 101 through an analog to digital converter (ADC) 111 . The node 101 can transmit audio data input through the ADC 111 to another node using a channel of the circulating packet 150 . The node 102 is connected to a mixer 121 . The node 102 can read audio data from a channel of the circulating packet 150 and transmit the audio data to the mixer 121 . The mixer 11 performs a variety of signal processing, such as mixing, audio volume level adjustment, and effecting, on the input audio data. The mixer 121 inputs the resulting audio data of the signal processing to the node 102 . The node 102 then can transmit the input audio data to another node using a channel of the circulating packet 150 . The node 103 is connected to a power amplifier 132 and a speaker 133 through a digital to analog converter (DAC) 131 . Similarly, the node 104 is connected to a power amplifier 142 and a speaker 143 through a DAC 141 . The node 103 can read audio data from a channel of the circulating packet 150 and transmit the audio data to the power amplifier 132 through the DAC and then output its sound through the speaker 133 . The same is true for the node 104 .
Each of the nodes 101 to 104 includes two-stage buffers (buffer A and buffer B). Each of the buffers stores audio data that can be read by a corresponding node. The purpose of providing the two-stage buffers is to store both sample data of one sampling cycle ago and latest sample data for each channel. Most recently read data is stored in one buffer (for example, 110 A) with the symbol “A” attached thereto and sample data of one sampling cycle ago is stored in another buffer (for example, 110 B) with the symbol “B” attached thereto.
FIG. 2 illustrates a hardware configuration of each node. One node includes a central processing unit (CPU) 201 , a random access memory (RAM) 202 , a read only memory (ROM) 203 , a communication interface (I/F) 204 , an audio I/O (input/output interface) 206 , and a communication bus 208 .
The CPU 201 is a processing unit that controls overall operations of the node. The RAM 202 is a volatile memory that is used as a loading region of programs executed by the CPU 201 or as a work region for setting a variety of buffers. The ROM 203 is a nonvolatile memory that stores a variety of programs to be executed by the CPU 201 , constant number data, and the like. The communication interface 204 is connected to another node 205 that is an external device. Since, for example, the node 102 is connected to both the nodes 103 and 101 although the node 205 is illustrated as one block in FIG. 2 , the node 102 includes a plurality of communication interfaces 204 for connection to the nodes 103 and 101 . The audio I/O 206 is an interface for connection with an external device such as an ADC, a DAC, a mixer, or the like.
A sample mismatching correction method or sampling cycle lag correction method for an audio network system of this embodiment will now be described. FIG. 8 illustrates the sample mismatching or sampling cycle lag correction method. Nodes A to D are connected in a ring allowing signals to reciprocate through the nodes. The node B is a master node. The master node B transmits a packet at the start time of one sampling cycle. Here, it is assumed that the node A stores data in a channel Ch 1 of the circulating packet, the node B stores data in a channel Ch 2 of the circulating packet, the node C stores data in a channel Ch 3 of the circulating packet, and the node D stores data in a channel Ch 4 of the circulating packet. It is also assumed that each of the nodes A to D reads data of all the channels Ch 1 to Ch 4 . Reference numeral “ 801 ” is data which has returned to the master node B in a sampling cycle “t−1” and which contains data set in each channel in the sampling cycle “t−1”. When a new sampling cycle “t” starts, the node B stores data of a cycle “t” in a Ch 2 region in the packet and transmits the packet as a packet 802 to the next node C. The node C receives the packet as a packet 803 and stores data of the cycle “t” in a Ch 3 region in the packet and then transmits it as a packet 804 to the next node D. The node D receives the packet as a packet 805 and stores data of the cycle “t” in a Ch 4 region in the packet and then transmits it as a packet 806 to the path of a backward line. The packet only passes through the nodes C and B on the backward line without change as shown by “ 807 ” and “ 808 ”. The next node A receives the packet as a packet 809 and stores data of the cycle “t” in a Ch 1 region in the packet and then transmits it as a packet 810 to the next node B. The master node B receives the packet as a packet 811 and waits until the next sampling cycle starts and then performs the same processes.
Each of the nodes includes buffers A and B as illustrated in FIG. 1 . For example, in the master node B, one row denoted by “ 822 A” is a buffer A which stores latest sample data of each channel and another row denoted by “ 822 B” is a buffer B which stores sample data of each channel of one sampling cycle ago. The same is true for other nodes. When transmitting a packet to the next node, each of the nodes A to D stores data of the channels Ch 1 to Ch 4 of the packet in the buffer A. Data that has been stored in the buffer until then is copied to the buffer B. The data storage in the buffer A is performed after the data copy is performed. Accordingly, each of the nodes A to D always contains a latest sample and a sample of one sampling cycle ago of each of the channels Ch 1 to Ch 4 in its buffers.
Each of the nodes A to D outputs sample data stored in the buffers A and B without causing mismatching of samples and, for example, delivers it to a mixer or outputs its sound through an amplifier. To prevent the sample mismatching, each node outputs data of one sampling cycle ago, which is stored in the buffer B, for channels which are subjected to writing at its upstream nodes (including a range of nodes from the master node to an immediately previous node) along the flow of data, which flows through the nodes in a ring, and outputs data of the current sampling cycle, which is stored in the buffer A, for channels which are subjected to writing at its downstream nodes (including a range of nodes from an immediately subsequent node to a node immediately prior to the master node). In the example of FIG. 8 , each node outputs data of a corresponding channel in the buffer B since the node stores data for writing of the current sampling cycle in the corresponding channel and thereafter writes it together with data of the other channels in the buffer A. Of course, each node may update data of a channel for writing at the node after storing its received packet in the buffer. When the procedure is performed in this order, the node outputs the data from the buffer A. In FIG. 8 , each item surrounded by an ellipse indicates a sample that each node outputs according to the rule described above. In this manner, mismatching of samples can be prevented and the samples of the cycle “t−1” can be output simultaneously.
Here, it is assumed that information of connection positions of the nodes and information about which channel is used for writing at each node are already shared among all the nodes. For example, when the system has started up, when a change has been made to the membership of nodes, or when a change has been made to channels set for writing or reading to or from a packet at each node, the nodes share this information, for example by exchanging control data with each other at the initiative of the master node.
Namely, the master node notifies all the slave nodes of control information representing at least a connecting position of each node in the audio network system and a channel allocated to each node, at the time when the audio network system starts up.
FIG. 3 is a flow chart of an audio data input routine that each of the nodes performs upon receiving a packet circulating through the nodes. At step 301 , audio data of a channel for inputting at the node is input to the node. In this process, for example, an audio signal from the microphone 112 is input to the node 101 of FIG. 1 through the ADC 111 or a digital audio signal output from the mixer 121 is input to the node 102 . At step 302 , data of the channel in the received packet is updated by overwriting the data of the channel with the latest sample input at step 301 . At step 303 , the node discards data of the channel in the buffer B in which samples of one sampling cycle ago have been stored. At step 304 , the data of the channel of the buffer B is overwritten with data of the channel of the buffer A in which samples of the current sampling cycle are stored. At step 305 , data of the channel of the buffer A is overwritten with data of the channel of the packet. When data of a plurality of channels is input, the node repeats the above procedure. The data discarding at step 303 is automatically performed by the overwriting at step 304 .
As described above, the node 101 is connected to a microphone 112 through an analog-to-digital converter 111 such that the analog-to-digital converter 111 converts an audio signal fed from the microphone 112 into audio sample data, and the node 101 writes the audio sample data fed from the analog-to-digital converter 111 into a region of a packet 150 so as to transmit the audio sample data to another node 102 .
FIG. 4 is a flow chart of an audio data output routine in which each node outputs sample data read into a buffer to an external device. In this procedure, for example, the node 102 of FIG. 1 outputs sample data to the mixer 121 or the node 103 or 104 outputs its sound through the DAC and the amplifier. At step 401 , the node determines whether or not output data of all channels, which will be output from the node, have been updated. This process is to determine whether or not all sample data of channels to be output has been gathered at a specific work area (for output data). If all the data has not yet been updated, the node (i.e., the current node) obtains, at step 402 , position information of a corresponding node at which a sample of the corresponding channel was stored. At step 403 , the current node determines whether the corresponding node is its upstream node (i.e., one in the range from the master node to its immediately previous node) or its downstream node (i.e., one in the range from its immediately subsequent node to a node immediately prior to the master node). If the corresponding node is an upstream node, the current node obtains sample data of the corresponding channel from the buffer B for one cycle ago at step 404 . If the corresponding node is a downstream node, the current node obtains sample data of the corresponding channel from the buffer A for the current cycle at step 405 . Then, the node updates the output data with the obtained data at step 406 and returns to step 401 . If the sample data of all channels to be output is gathered together as output data, the node proceeds from step 401 to step 407 and performs an audio data output time correction process which will be described later. Then, at step 408 , the node outputs audio data of channels, which is set to be output from the node, to a specified external device.
As described above, one node 102 is connected to a mixer 121 . The node 102 outputs the audio sample data of the allocated channel to the mixer 121 so that the mixer 121 applies a predetermined signal process to the audio sample data transmitted from the node 102 and feeds audio sample data applied with the predetermined signal process. The node 102 includes an updating part that writes the audio sample data fed from the mixer 121 a region of a packet 150 so as to transmit the audio sample data to another node 103 .
The node 103 is connected to an amplifier 132 of a speaker 133 through a digital-to-analog converter 131 . The node 103 outputs the audio sample data of the allocated channel to the digital-to-analog converter 131 so that the digital-to-analog converter 131 converts the outputted audio sample data to an analog audio signal, and the amplifier 132 amplifies the analog audio signal for driving the speaker 133 .
In the above manner, each node performs the sampling cycle lag correction described with reference to FIG. 8 and simultaneously outputs samples of the same sampling cycle.
Although 2-stage buffers are provided in FIG. 8 , (n+1)-stage buffers may be provided, where “n” is an integer equal to or greater than 1. In this case, n+1 audio sample data including a range of samples from samples read in the current sampling cycle to samples read in n sampling cycles ago are stored. When a sample in a packet is to be output from the current node which has received the packet, the current node may read and output a corresponding sample of n sampling cycles ago if a corresponding node which incorporated the sample into the packet is upstream of the current node and may read and output a corresponding sample of n−1 sampling cycles ago if the corresponding node is downstream of the current node.
The audio data output time correction process of step 407 will now be described in detail. The above sample deviation correction can match output timings on a sample basis. However, each transmission path between nodes on the ring network causes a delay since sample data of each channel is transmitted by incorporating the data into a packet that circulates through the ring network. Although this delay may be very small and thus be negligible, even such a small delay may not be permitted in professional audio devices. The audio data output time correction process is performed to correct the delay due to the transmission path, thereby very accurately matching the output timings of audio signals from the node.
The following is a detailed description of the audio data output time correction process. The following description will be given with reference to a network having a connection structure allowing signals to reciprocate through the network as shown in FIG. 13 . It is also assumed that each node performs writing and reading of data to and from a packet on a forward path and the packet only passes through each node on a backward path. In the following description, “t(a)” denotes a delay time for a line length “a”, “T FT ” and “T FR ” denote forward-side transmission/reception times of each of the nodes 901 and 902 , and “T BT ” and “T BR ” denote backward-side transmission/reception times as shown in FIG. 9 . In addition, “Total Delay” denotes a total delay time of the network, “Forward Delay” and “Backward Delay” denotes delay times of the forward and backward sides of the master node, and “Node (Name) Delay” denotes the difference between packet reception times of each node. That is, “Total Delay” is a delay time corresponding to a period of time during which the packet circulates through the network once. “Forward Delay” is a delay time corresponding to the time that elapses until the master node receives data at its forward side after the data is transmitted from the master node at its forward side. “Backward Delay” is a delay time corresponding to the time that elapses until the master node receives data at its backward side after the data is transmitted from the master node at its backward side.
The term “forward side” refers to one side of the master node at which the master node starts transmitting a packet at the start of a sampling cycle and the term “backward side” refers to the opposite side. In FIG. 9 , the right side is the forward side and the left side is the backward side. The same is true for FIGS. 10 and 11 .
FIGS. 10 a to 10 c illustrate delay times calculated by a master node. FIG. 10 a illustrates an example where a master node 1001 is disposed at a backward end of a network and a backward-side output of the master node 1001 is connected directly to a backward-side input thereof inside the master node 1001 . FIG. 10 b illustrates an example where a master node 1012 is connected between slave nodes 1011 and 1013 and the slave nodes 1011 and 1013 are connected respectively to a backward-side input and output and a forward-side input and output of the master node 1012 . FIG. 10 c illustrates an example where a master node 1023 is disposed at a forward end of a network and a forward-side output of the master node 1023 is connected directly to a forward-side input thereof inside the master node 1023 . The respective delay times “Total Delay”, “Forward Delay”, and “Backward Delay” of the examples are calculated as illustrated in FIGS. 10 a to 10 c . Although the delay time calculation is exemplified by three nodes in these examples, the delay times are calculated in the same manner also when a larger number of nodes are connected.
As described above, the master node determines the total network delay time, the forward-side delay time, and the backward-side delay time according to a length of lines “a” and “b” for connecting the nodes. The master node may determine either of the forward-side delay time and the backward-side delay time to be zero in case that either of the first part or the second part of the plurality of the slave nodes is not connected to the master node as depicted in FIGS. 10 a and 10 c.
FIGS. 11 a to 11 f illustrate delay times calculated by slave nodes. Each slave node calculates, as a delay time, the difference between packet data reception times of the forward and backward sides of the slave node. This delay time is calculated using different calculation methods depending on the positional relationship with the master node. For example, slave nodes 1102 and 1103 (entitled “S 3 ” and “S 4 ”) which are located on the forward side of the master node 1101 calculate the delay time as “T FR −T BR ” as shown in FIGS. 11 d and 11 e . On the other hand, slave nodes 1104 and 1105 (entitled “S 1 ” and “S 2 ”) which are located on the backward side of the master node 1101 calculate the delay time as “T BR −T FR ” as shown in FIGS. 11 b and 11 c . In the connection example of FIG. 11 a , the master node 1101 calculates delay times as shown in FIG. 11 f.
As described above, the terminal slave nodes S 1 and S 4 calculate their reception time difference to be zero as depicted in FIGS. 11 b and 11 e.
FIGS. 12 a to 12 c illustrate examples of calculation of a correction time for each node, which is the time by which the node delays the output time of sample data when outputting the sample data to an external device such as a mixer or an amplifier. The horizontal axis of FIG. 12 a represents elapsed time and symbols “S 1 ”, “S 2 ”, “M”, “S 3 ”, and “S 4 ” arranged along the vertical axis represent the master and slave nodes of FIG. 11 a . Arrows in “M S 3 S 4 S 3 M S 2 S 1 S 2 M” FIG. 12 a indicate that packet data circulates through the nodes along the arrows in the network structure of FIG. 11 a , where the right-down arrows indicate a forward path and the left-down arrows indicate a backward path. “ 1024 ” denotes delay times between the nodes when packet data circulates along the arrows. “ 1201 ” denotes the total delay, “ 1202 ” denotes the forward delay, and “ 1203 ” denotes the backward delay.
Reference numeral “ 1213 ” in FIG. 12 a denotes the timing when the slave node S 3 receives a packet transmitted from the master node M. Upon receiving the packet, the node S 3 performs the above procedure of FIG. 4 . Similarly, the node S 4 performs the procedure of FIG. 4 at timing 1214 , the node S 1 performs the procedure at timing 1211 , and the node S 2 performs the procedure at timing 1212 . If the nodes do not perform the output time correction of step 407 in the procedure of FIG. 4 , the nodes output audio data at different timings since the node S 3 outputs audio data at the timing 1213 , the node S 4 outputs audio data at the timing 1214 , and so on. Accordingly, in this embodiment, the timings 1213 , 1214 , 1211 , and 1212 of the nodes are delayed until the timing 1210 . The timing 1210 is the timing when the packet returns to the master node. If they wait until the timing 1210 , all the nodes gather together samples of the same sampling cycle. By simultaneously outputting the samples, it is possible to very accurately match the output timings of audio signals from the nodes. The delay time of each node until the timing 1210 is reached after it receives the packet is referred to as a correction time. In FIG. 12 a , “ 1221 ” to “ 1224 ” indicate respective correction time calculation methods of the nodes.
FIG. 12 b illustrates a correction time calculation method for the forward-side slave nodes. The forward-side slave nodes are for example the nodes S 3 and S 4 . The correction time of each of the nodes S 3 and S 4 can be basically calculated as the time that elapses until a packet returns to the master node after the packet is input to the node through its backward-side input (T BR ) so that it can be calculated as “Total Delay−{(Total Delay)−(Backward Delay)−(Node (Name) Delay)}/2”. This expression can be rearranged to obtain an expression of FIG. 12 b . Equations 1223 and 1224 are obtained by substituting the equations of FIG. 11 f into the expression of FIG. 12 b.
FIG. 12 c illustrates a correction time calculation method for the backward-side slave nodes. The backward-side slave nodes are for example the nodes S 1 and S 2 . The correction time of each of the nodes S 1 and S 2 can also be basically calculated as the time that elapses until a packet returns to the master node after the packet is input to the node through its backward-side input (T BR ) so that it can be calculated as “{(Total Delay)−(Forward Delay)−(Node (Name) Delay)}/2”. This expression can be rearranged to obtain an expression of FIG. 12 c . Equations 1221 and 1222 are obtained by substituting the equations of FIG. 11 f into the expression of FIG. 12 c.
FIG. 5 is a flow chart of a delay time calculation routine for a master node. At step 501 , the master node calculates a total delay time (Total Delay) of the network. At step 502 , the master node calculates a forward-side delay time (Forward Delay). At step 503 , the master node calculates a backward-side delay time (Backward Delay). At step 504 , the master node notifies all nodes of the calculation information. Through this procedure, the master node calculates each delay time described above with reference to FIG. 10 .
FIG. 6 is a flow chart of a delay time calculation routine for each slave node. At step 601 , each slave node obtains total network, forward-side, and backward-side delay time information (Total Delay, Forward Delay, and Backward Delay). At step 602 , the node determines whether it is located on the forward side or the backward side. If it is located on the forward side, the node obtains its packet time reception difference at step 603 and calculates a correction time using the mathematical expression of FIG. 12 b at step 604 . If it is located on the backward side, the node obtains its packet time reception difference at step 605 and calculates a correction time using the mathematical expression of FIG. 12 c at step 606 .
Through the procedures of FIGS. 5 and 6 , the nodes can calculate their delay times described above with reference to FIGS. 10 and 11 . Before audio data transmission is initiated, the slave nodes perform the procedures of FIGS. 5 and 6 and calculate their correction times.
FIG. 7 is a flow chart of an audio data output routine for a slave node. The node performs this procedure at step 407 of FIG. 4 . The node resets a timer at step 701 and waits, at steps 702 and 703 , until the timer value exceeds the correction time which the node has calculated at step 604 or 606 . If the timer value has exceeded the correction time, the node returns to the procedure of FIG. 4 . Thereafter, the node outputs audio data at step 408 of FIG. 4 . In this manner, each node outputs audio data by delaying it by a correction time for the node as described above with reference to FIG. 12 , thereby matching the output timings of all the nodes.
While the above embodiments have been exemplified by the audio network system having the connection relationship as shown in FIG. 13 , the invention can be applied to any audio network system which connects a plurality of nodes in a ring to circulate a packet through the nodes. In this case, each node obtains the time that elapses from when the node receives a packet to when the master node receives the packet and determines it to be a correction time. For example, when the system starts up, it may circulate a correction time measurement packet so that each node obtains, as a correction time, the time that elapses from a time when the node receives a packet to another time when the master node receives the packet.
Lastly, the following is a detailed mechanism of time lags of samples created among the nodes. This description is simply intended to facilitate better evaluation of the invention. FIG. 15 b illustrates a ring audio network system in which nodes A to D are connected in such a manner that a signal reciprocates along the nodes as shown in FIG. 13 . The node B is a master node. The master node B transmits a packet at the start time of one sampling cycle.
Here, it is assumed that, as shown in FIG. 15 a , the node A stores data in a channel Ch 1 of the circulating packet, the node B stores data in a channel Ch 2 of the circulating packet, the node C stores data in a channel Ch 3 of the circulating packet, and the node D stores data in a channel Ch 4 of the circulating packet. It is also assumed that each of the nodes A to D reads data of all the channels Ch 1 to Ch 4 . Reference numeral “ 1501 ” is data which has returned to the master node B in a sampling cycle “t−1” and which contains data set in each channel in the sampling cycle “t−1”. When a hew sampling cycle “t” starts, the node B stores data of a cycle “t” in a Ch 2 region in the packet and transmits the packet as a packet 1502 to the next node C. The node C receives the packet as a packet 1503 and stores data of the cycle “t” in a Ch 3 region in the packet and then transmits it as a packet 1504 to the next node D. The node D receives the packet as a packet 1505 and stores data of the cycle “t” in a Ch 4 region in the packet and then transmits it as a packet 1506 to the path of a backward line. The packet only passes through the nodes C and B on the backward line without change as shown by “ 1507 ” and “ 1508 ”. The next node A receives the packet as a packet 1509 and stores data of the cycle “t” in a Ch 1 region in the packet and then transmits it as a packet 1510 to the next node B. The master node B receives the packet as a packet 1511 and waits until the next sampling cycle starts and then performs the same processes.
While the packet circulates in the above manner, the nodes A to D read data of the channels Ch 1 to Ch 4 of the packets 1510 , 1511 , 1504 , and 1506 surrounded by ellipses, respectively. In this case, while the master node A and its immediately previous node B obtain samples of the cycle “t”, sample mismatching occurs in the nodes C and D. That is, each of the nodes C and D reads a mix of samples of the cycle “t−1” and samples of the cycle “t”. The sample mismatching occurs for the following reason. In the case where a packet circulates through nodes on a network, starting from a master node, once in a sampling cycle, data stored in a node in a sampling cycle “t” may be extracted from one different node in the sampling cycle “t” while it may be extracted from another different node in the next sampling cycle, depending on the arrangement of the nodes on the network (i.e., depending on the positional relationship of nodes in which data is stored and nodes from which data is extracted). | In an audio network system connecting a plurality of nodes in a ring form, a master node transmits a packet of frame data regularly every sampling cycle, such that the packet circulates through the nodes during the sampling cycle. The packet is provided with a plurality of regions for containing audio sample data in correspondence to a plurality of channels. A first node reads audio sample data from a particular region of the packet, which corresponds to a particular channel allocated to the first node, and stores the read audio sample data in a buffer. The first node acquires positional information indicating whether a second node which has written the audio sample data into the particular region is located upstream or downstream of the first node. The first node reads and outputs a previous one of the audio sample data from the buffer if the second node is located upstream of the first node, and outputs a current one of the audio sample data if the second node is located downstream of the first node. | 7 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a method for repairing asphalt roads, parking lots, driveways, and other structures which may utilize a stratum of asphalt, bituminous, concrete, or similar material. More particularly, the invention comprises a method of forming a patch or filling of a hole in such a road, lot, driveway, or structure. The method includes a step of accelerating curing or hardening of hot asphalt mix employed to fill the hole by application of a cryogenic material.
2. Description of the Prior Art
Asphalt surfaces, such as roads, parking lots, alleys, driveways, and the like are subject to deterioration over time. This may occur as a result of freezing and expansion cycles, ground heaving, overweight vehicles, and other causes. Limited areas of the surface may break or exhibit holes, which then must be repaired. Typically, pavement is repaired by filling holes with asphalt or concrete alone. While this method is relatively quickly performed, the resulting patches lack durability. The original problem may recur within one or two years.
The prior art has suggested modifications to methods of constructing or patching asphalt roads by merely laying down and rolling a stratum of asphalt. For example, the asphalt stratum may be reinforced. In U.S. Pat. No. 4,699,542, issued to Roy Shoesmith on Oct. 13, 1987, there is described a method of reinforcing roadway by placing a filament fiberglass mesh in the asphalt. However, unlike the present invention, there is no chilling of the asphalt. Nor does Shoesmith lay down a water barrier nor interweave partially rigid rods through the mesh, both steps being features of the present invention.
U.S. Pat. No. 5,405,212, issued to George W. Swisher on Apr., 11, 1995, describes apparatus for paving with concrete, there being provision for inserting a dowel rod into uncured concrete. But because Swisher addresses concrete construction and not asphalt, chilling is inappropriate in Swisher's method. In further contrast to the present invention, Swisher fails to teach use of a water barrier and interweaving reinforcing rods into a mesh.
Pavelek, II describes a road construction incorporating an internal stratum of asphalt roofing shingle material which, among other properties, serves as a liquid barrier. However, Pavelek, II fails to teach chilling of asphalt and placing of a reinforcing mesh in asphalt.
My prior U.S. Pat. No. 5,464,303, issued on Nov. 7, 1995, describes mesh reinforcement of asphalt repairs and reinforcing rods, but lacks improvements disclosed herein. These improvements include forming flat surfaces on the reinforcing rods, and utilizing chilling of the asphalt fill material.
None of the above inventions and patents, taken either singly or in combination, is seen to describe the instant invention as claimed.
SUMMARY OF THE INVENTION
The present invention greatly improves upon current patching and repairing methods applied to asphalt and concrete surfaces of roads and the like. These surfaces will hereinafter collectively be termed road surfaces for brevity. The patch is protected by a water barrier placed first in the hole or area being repaired. A water barrier is preferably a flexible sheet of material having a nominal thickness and preventing passage therethrough of water in either liquid or gaseous form. Next, a mesh having rods laid on the mesh or interwoven therethrough is placed over the water barrier. Then, the hole is filled with hot asphalt mix, which is then compacted by tamping or rolling.
At or towards the end of the compacting step, the asphalt is subjected to extreme chilling. Preferably, the temperature of the chilled medium contacting the asphalt is in a cryogenic range of temperatures, that being below any temperature naturally encountered on Earth. However, benefits from chilling will still be present even if the temperature of the chilling medium is above the cryogenic range. Therefore, methods similar to the preferred novel repair method may be employed without resorting to handling cryogenic materials.
An illustration of a preferred chilling medium is liquid nitrogen. Liquid nitrogen is among the least expensive of commercially available cryogenic materials, and also among the most user friendly. It can therefore be handled and employed with minimal risk of damage to equipment and injury to personnel. Of course, some care is necessary in handling any cryogenic material.
The liquid nitrogen, or cold vapors resulting from evaporation of liquid nitrogen, may be directly discharged onto freshly compacted asphalt. Alternatively, the roller of a power rolling machine may be chilled with liquid or vaporous nitrogen. It would even be possible to inject a cryogenic substance into the asphalt.
A preferred material for fabricating the water barrier, the reinforcing mesh, and the reinforcing rods woven through the mesh is recycled plastic. This is both an efficient use of an otherwise waste material, and also a convenient, cooperative constituent material for the components of the repair. Melting and softening temperatures of recycled plastic are above temperatures conventionally attained by asphalt mix, i.e., up to 325° Fahrenheit. However, if desired, the water barrier may be fabricated from commercially available cross linked or cross laminated virgin plastic sheet material, preferably in the range of 3 to 7 mils in thickness.
At these temperatures, the water barrier will become quite flexible, but is unlikely to rupture. Flexibility is desirable in repairs since the water barrier will exhibit a greater tendency to conform to the exposed or upper surface of the untreated hole than would otherwise occur.
The water barrier promotes deterrence of permeation of water through the repaired road surface. This feature alone will improve longevity of the repair and of the road surface.
Chilling hastens and improves internal bonding within the repair patch and of the repair patch to the original road surface. In particular, deformation of the new repair by traffic employing the road surface shortly after completion of the repair is minimized. This also improves longevity of the repair.
Placement of reinforcing members in the asphalt serves several purposes. One is that loads imposed on the repair or patch are distributed and absorbed throughout greater area of asphalt. This reduces peak loading of local areas, and slows deformation of the asphalt surface. Mass movement or shifting of material of the road responsive to forward and lateral loads imposed by traffic is prevented. The overall coherence of the patch is improved, and sections are less likely to break away over time.
In an improvement over the rods shown in my previous patent, the rods are formed with a flat portion formed in the external circumferential surface. This reduces tendency to roll when the rods are merely laid on the mesh rather than interwoven therethrough.
Also, structural reinforcing members may be exploited to contain sensors for sensing passing traffic. This enables installation of sensors at the same time as performing repairs. Also, supporting members for the sensors are provided, so that a network of sensors is more quickly and expediently located in an asphalt surface.
Thus, it will be seen that improved repair to asphalt may be performed quickly and conveniently. The improved method of repair employs generally conventional equipment and procedures for distribution of hot asphalt, and hence entails no highly unusual steps requiring retraining of personnel or expensive purchases of equipment. Yet the repair will enjoy benefits of greatly improved longevity and strength.
It would also be feasible to construct new roads or other asphalt surfaces by employing the principles disclosed herein. The invention may be regarded as repairing existing asphalt surfaces and also constructing new asphalt surfaces not associated with pre-existing asphalt surfaces. Therefore, it will be understood that references to repair will apply equally to new construction.
Accordingly, it is a principal object of the invention to provide a method of repairing an asphalt surface which improves longevity of the repair over that of conventional repair methods.
It is another object of the invention to provide immediate internal bonding of asphalt material upon compacting this material when repairing an asphalt surface.
It is a further object of the invention to provide a water barrier promoting deterrence of water permeation through the repaired asphalt surface.
Still another object of the invention is to provide reinforcement members in the improved or repaired asphalt surface.
An additional object of the invention is to make use of recycled plastic scrap material.
It is again an object of the invention to provide a quickly performed and economical method of repairing asphalt surfaces.
Yet another object of the invention is to enable convenient placement of traffic sensors in a roadway.
A still further object of the invention is to prevent reinforcing rods from rolling when laid on reinforcing mesh.
It is an object of the invention to provide improved elements and arrangements thereof in an apparatus for the purposes described which is inexpensive, dependable and fully effective in accomplishing its intended purposes.
These and other objects of the present invention will become readily apparent upon further review of the following specification and drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
Various other 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 an environmental, cross sectional, partly exploded view of the invention.
FIG. 2 is a top plan detail view of reinforcing mesh and rods shown at the center of FIG. 1.
FIG. 3 is a block diagram of steps of a method of practicing the invention.
FIG. 3A is a partial block diagram illustrating an alternative step of the method of FIG. 3.
FIG. 4 is an environmental, side elevational, partly cross sectional view illustrating an optional method of chilling asphalt.
FIGS. 5, 6, and 7 are block diagrams each illustrating an optional step which may be practiced with the method of FIG. 3.
FIG. 8 is an end elevational, cross sectional view of a rod, taken at line 8--8 of FIG. 2.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Turning now to FIG. 1 of the drawings, the novel method of repairing an asphalt surface 10 having a hole 12 is illustrated by showing hole 12 in a condition prepared for hot asphalt fill material 14 to be discharged into hole 12. Hole 12 is merely representative of different forms of voids formed in asphalt surface 10, which voids are to be filled in order to restore a generally flat upper surface 16 of asphalt surface 10. For brevity, all such voids will be referred to as hole 12.
Hole 12 is suitably prepared for repair. Preparation may include removing loose debris, accumulated water, and other materials which will interfere with bonding of fill material 14 or which may impair desirable properties of asphalt surface 10 in any way. This step is completely conventional. Asphalt fill material 14 is also of conventional constituents, and may be poured in conventional manner. Conventional asphalt distributing equipment is represented by chute 18.
A first novel step in the repair method is lining hole 12 with a water or vapor barrier 20. The second novel step is placing a reinforcing mesh 22 in the hole. FIG. 2 shows a preferred reinforcing mesh 22 and rods 24 which are interwoven through mesh 22. It will be seen in FIG. 2 that rods 24 are oriented at oblique angles 26, 28 to the linear dimensions 30, 32 of mesh 22. Preferably, rods 24 are disposed to intersect with other rods 24 which are also oriented at oblique angles 34, 36 to dimensions 30, 32 of mesh 22.
Mesh 22 is preferably includes linear structural members 38 and 40 disposed perpendicularly to one another, being fused or joined at intersections 42. Preferred construction of mesh 22 and of rods 24 is more fully discussed in my prior U.S. Pat. No. 5,464,303, issued on Nov. 7, 1995, Ser. No. 08/175,933, filed Dec. 30, 1993, which is incorporated herein by reference.
Returning now to discussion of the novel method, and with reference to FIG. 3 as well as FIGS. 1 and 2, the first novel step of lining hole 12 with liner 20 is designated 50. The second step of placing mesh 22 in hole 12 is designated 52. A third step 54 is interweaving rods 24 through mesh 22. Step 56 is orienting rods 24 at an oblique angle to linear structural members 38 and 40 of mesh 22.
Rods 24 are of any cross sectional configuration other than round or circular, so that they will not roll when place on or in mesh 22. Additional advantages of non-round or non-circular configuration are that rods 24 are easier to bend when interweaving through mesh 22, and are easier to grasp when interweaving. A preferred embodiment of a flattened rod 22 is shown in FIG. 8.
To reduce time of installation, rods 24 are optionally laid on mesh 22 rather than interwoven therethrough. The term "on" will be understood to signify that each rod 24 is entirely above, although possibly in contact with, mesh 22. This is in contrast to interwoven therethrough, wherein sections of a rod 24 periodically pass over a member of mesh 22.
Incorporation of rods 24 provides reinforcement which is particularly useful in cases wherein the repair is subjected to tangential forces from braking vehicles. Bus stops are frequently the subject of repairs, and also are highly susceptible to tangential forces arising from busses as they brake to a stop. Rods 22 reduce tendency of the repair from eventually being broken away from effective bonding with surface 10.
The method summarized in FIG. 3 may be modified by omitting step 54, and substituting step 54A illustrated in FIG. 3A.
Hole 12 is then filled with hot asphalt fill material 14 in the next step 58. A subsequent step 60 is compacting hot asphalt fill material 14. Steps 58 and 60 may be performed with conventional materials and equipment.
A further novel step 62 is chilling hot asphalt fill material 14. Chilling asphalt material 14 will be understood to signify active steps to reduce temperature of asphalt at working temperatures. Mere neglect of laid asphalt at working temperatures, typically in the range of 275°-325° Fahrenheit, will result naturally in heat transfer to the environment by radiation, convection, and conduction. This is a purely passive process as related to human effort. Therefore, for purposes of defining the novel process, the step of chilling is differentiated from passive heat loss by actual steps to reduce temperature of laid asphalt by subjecting the laid asphalt to temperatures below those encountered under normal working conditions.
Normal working conditions may include discharging of water onto rollers of compaction equipment. Cooling obtained by contact of water with asphalt is inadequate for the purposes of this invention. Cooling will be understood to encompass provision of a chilling medium having temperatures below freezing. This is best accomplished when the temperature difference between the chilling medium and the freshly laid asphalt is maximal. This condition is produced by employing cryogenic substances, with or without phase change of the cryogenic substance. However, since economics has great impact upon asphalt repair, if an inexpensive or convenient source of a chilled medium is at hand, then it may be preferable to employ a chilling medium above cryogenic temperatures, as discussed prior.
Step 62 of chilling asphalt fill material 14 may be accomplished in several ways. Obviously, a chilled medium may be poured, sprayed, or otherwise discharged onto laid asphalt (this process is not shown). A preferred method is illustrated in FIG. 4. It is preferred that a cryogenic substance be introduced into heat exchange relation to a surface 44 of compaction equipment, such as powered roller 46, contacting the new patch 48. This method is summarized as step 64 in FIG. 5. Step 64 is a modification or variation of step 62 of FIG. 3.
Preferred chilling media include liquid nitrogen and liquid carbon dioxide. These materials may be stored within roller 46, as shown by tank 66 in FIG. 4. Steps of employing liquid nitrogen and liquid carbon dioxide are modifications or variations of step 62 of FIG. 3, and are shown as step 68 of FIG. 6 and step 70 of FIG. 7, respectively.
It will be appreciated that provision of water barrier 20, mesh 22, and rods 24 are independent of the step 62 of chilling newly laid asphalt fill material 14. Also, provision of water barrier 20 is independent of provision of structural reinforcing members, such as mesh 22 and rods 24.
The essence of the present invention is to chill newly laid asphalt, as described prior. Steps of the essential invention include the step 58 of filling hole 12 with hot asphalt fill material 14, step 60 of compacting hot asphalt fill material 14, and step 62 of chilling asphalt fill material 14 after filling hole 12.
Not absolutely essential, but regarded as significantly improving longevity of the repair in environments subject to presence of water in any form, is step 50, lining hole 12 with water barrier 20. Also not essential, but regarded as effective in distributing loads over greater area, is reinforcing new patch 48 (see FIG. 4). Additional steps of the essential method of steps 58, 60, and 62, or of the improved method incorporating step 50, are step 52 of placing reinforcing mesh 22 in hole 12, step 54 of interweaving rods 24 through mesh 22, and step 56 of orienting rods 22 at oblique angles 26, 28, 34, or 36 to linear members 38, 40 of mesh 22. Of course, steps 52, 54, and 56 may be utilized without utilizing step 52.
In variations of step 62, or in subsequent steps, any of the above methods may be practiced by including a further step of subjecting asphalt fill material 14 to heat exchange relationship with a cryogenic temperature. This may be accomplished, illustratively but not exclusively, by step 68 of FIG. 6, utilizing liquid nitrogen as a chilling medium, or by step 70 of FIG. 7, utilizing liquid carbon dioxide as the chilling medium.
Obviously, it is the temperature and not the actual phase of the chilling medium that is crucial to the invention. When employed for cryogenic purposes, nitrogen may be in the liquid state, gaseous or vapor state, or both when transferring heat from the contact surface 44 of compaction equipment 46 (see FIG. 4). The same holds true for other cryogenic substances or mixtures of several cryogenic substances. In the case of liquid carbon dioxide and other materials subject to sublimation, it is possible that solid and gaseous states only be encountered.
Regardless of temperature of the chilling medium, it is regarded as most practical to subject material 14 to reduced temperature by step 64 of FIG. 5, chilling contact surface 44 (see FIG. 4) of compaction equipment 46. Of course, chilling media (not shown) may be introduced to patch 48 in other ways, such as by injection thereinto.
It is to be understood that the present invention is not limited to the embodiments described above, but encompasses any and all embodiments within the scope of the following claims. | A method of repairing asphalt or concrete surfaces such as roads and parking lots which have developed pot holes therein. The hole is cleaned of loose debris, lined with a water barrier sheet, provided with a reinforcing mesh, and filled with hot asphalt mix. The asphalt mix is compacted by a roller which has been chilled by exposure to a cryogenic substance, such as liquid nitrogen. Alternatively, the cryogenic substance directly contacts the asphalt mix. Preferably, the reinforcing mesh is further reinforced by flattened rods woven through the mesh or alternatively, laid thereon, with the rods oriented at angles of approximately forty-five degrees to linear structural members of the mesh. The water barrier, reinforcing mesh, and reinforcing rods are preferably formed from recycled plastic materials. | 4 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present regular United States Patent Application claims the benefits of U.S. Provisional Application Ser. No. 60/736,209, filed on Nov. 14, 2005.
FIELD OF THE INVENTION
[0002] The present invention relates generally to movement dampers and, more particularly, the invention pertains to linear dampers providing high resistance.
BACKGROUND OF THE INVENTION
[0003] Movement dampers have many applications and uses for controlling the movement of things. Dampers are used extensively in automotive applications for controlling the movement of glove box doors, cup holders, assist handles and the like. Dampers are often used to control the natural gravitational movement of such components, and to provide a desired feel to the movement of the component being controlled. Uses for dampers in assemblies other than automobiles are also known widely, such as, for example, and not by way of limitation, furniture doors and drawers, appliances, electronic components and other assemblies that have doors, drawers and other components that open or close, move in and out, fold up and down, etc.
[0004] It is known to provide center consoles between occupant seats in automobiles, trucks, SUV's and the like. In larger vehicles, the center console can be quite large. Often a door is provided on the top of the console having a hinge at the back and a latch at the front. The door is opened by lifting the front edge upward, thus pivoting the door on the hinge at the back. Such console doors can be both bulky and heavy. Opening can be assisted by springs or the like so that the vehicle occupant is not burdened with lifting the entire weight of the door. Movement dampers can be used to lessen the closing force from the weight of the door, thereby preventing the door or cover from falling shut forcefully, potentially causing damage.
[0005] It is often desirable for dampers of this type to work in confined spaces, yet provide significant resistance to the gravitational movement of the object. Limited space can require straight line movement. It is known for damping requirements to be in one direction only, with the damper providing significant resistance in the desired direction and with little or no resistance or damping effect in the opposite direction.
[0006] In automobile applications it is desirable for a damper to work effectively without adjustment and to perform satisfactorily through many cycles without failing. Also, it is desirable for the damper to be small and operate effectively in a confined space, to minimize the intrusion in the occupant space of the vehicle.
[0007] Accordingly, there is need for improved linear dampers.
SUMMERY OF THE INVENTION
[0008] The present invention provides a linear damper with an engaging/disengaging structure whereby the damper provides significant resistance to the movement of a rod in one direction but little resistance to movement of the rod in the opposite axial direction.
[0009] In one aspect thereof, the present invention provides a linear damper with a damping assembly and a rod extending through the damping assembly, the damping assembly and the rod configured and arranged for relative axial movement therebetween. The damping assembly includes a friction member therein disposed adjacent the rod. The friction member is actuated by movement of the rod in one axial direction to provide clamping force against the rod and by movement in an opposite axial direction to release clamping force applied against the rod.
[0010] In another aspect thereof, the present invention provides a linear damper with a conical housing, a friction cone disposed for axial movement in the housing and a rod extending through the friction cone and the housing. The friction cone is expandable and contractible upon axial movement in the conical housing to apply and release clamping pressure against the rod when relative axial movement occurs between the rod and the housing.
[0011] In a further aspect thereof, the present invention provides a linear damper with a damping assembly including a conical housing and a cap defining an axial opening therethrough. A friction cone is disposed in the housing and axially movable therein. The friction cone has an axial slit from one end thereof to the other end thereof. A rod extends through the housing, the cap and the friction cone in the housing, and is movable axially relative to the friction cone.
[0012] An advantage of the present invention is providing a linear damper that operates in a small space.
[0013] Another advantage of the present invention is providing a linear damper that is simple and inexpensive to manufacture and supply.
[0014] Still another advantage of the present invention is providing a linear damper that provides damping in one direction for movement of a rod, with little or no damping in an opposite direction of movement.
[0015] Yet another advantage of the present invention is providing a linear damper that requires little or no adjustment and can operate through many cycles of operation.
[0016] Other features and advantages of the invention will become apparent to those skilled in the art upon review of the following detailed description, claims and drawings in which like numerals are used to designate like features.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] FIG. 1 is a perspective view of a linear damper in accordance with the present invention;
[0018] FIG. 2 is a longitudinal cross-sectional view of the linear damper shown in FIG. 1 ;
[0019] FIG. 3 is a perspective view of a friction cone for the linear damper of the present invention; and
[0020] FIG. 4 is a perspective view of an automobile console having linear dampers in accordance with the present invention.
[0021] Before the embodiments of the invention are explained in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangements of the components set forth in the following description or illustrated in the drawings. The invention is capable of other embodiments and of being practiced or being carried out in various ways. Also, it is understood that the phraseology and terminology used herein are for the purpose of description and should not be regarded as limiting. The use herein of “including”, “comprising” and variations thereof is meant to encompass the items listed thereafter and equivalents thereof, as well as additional items and equivalents thereof.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0022] Referring now more specifically to the drawings and to FIG. 1 in particular, numeral 10 designates a linear damper in accordance with the present invention. While linear dampers of the present invention are expected to have a variety of advantageous applications and uses, one particularly advantageous use is to control the closing movement of automobile console doors. FIG. 4 illustrates an automobile console 12 having a base or bin 14 and a cover 16 . Cover 16 is connected to bin 14 by a hinge 18 . Two linear dampers 10 of the present invention are illustrated to control closing movement of cover 16 . Console 12 is merely one example of a suitable use, and the description thereof to follow should not be considered as a limitation on the application and use of the present invention.
[0023] Damper 10 includes a damping assembly 20 and a rod 22 axially movable relative to damping assembly 20 .
[0024] Rod 22 is a substantially linear, elongate body having a base 24 at one end thereof and a head 26 at an opposite end thereof. The shapes, sizes and the like of base 24 and head 26 , as well as the length and thickness of rod 22 , can be selected for the particular application and use of the present invention. For example, head 26 can be configured with a curved surface as shown for rolling type engagement with a surface pushing thereagainst in a pivotally rotational movement, such as the engagement of damper 10 with cover 16 of console 12 . Further, base 24 and head 26 can be configured to limit axial movement of rod 22 , so that rod 22 cannot slide completely through damping assembly 20 inadvertently. Rod 22 , base 24 and head 26 can be made of injected molded plastic or the like.
[0025] Damping assembly 20 includes a housing 30 and a cap 32 . A friction cone 34 is disposed in housing 30 . Housing 30 and cap 32 can be injection molded plastic or other suitable material, assembled in known manner.
[0026] Housing 30 is a conically shaped structure, at least with respect to the inside thereof, and has a tapered sidewall 36 defining an opening 38 at the bottom there of. In the exemplary embodiment, several flanges 40 , 42 and/or mounting tabs 44 , 46 are provided for installation and securement of damper 10 in its operating position within an assembly, and for providing desired levels of rigidity and strengthening.
[0027] Cap 32 closes an open top of the conically shaped housing sidewall 36 , and has an opening 50 in alignment with opening 38 in housing 30 . Rod 22 is extended slidably through openings 38 and 50 . Various configurations for attaching cap 32 to housing 30 can be used, and in the exemplary embodiment a channel 52 in cap 32 receives an upper edge 54 of housing 30 . Sonic welding, adhesive, frictional engagement and the like all can be used to secure cap 32 to housing 30 .
[0028] Friction cone 34 includes an outer shell 60 and an inner liner 62 . Shell 60 can be made of a plastic or other similar material and is shaped to fit in conically shaped housing 30 . Liner 62 is rubber, either natural or synthetic such as a thermoplastic or neoprene, with a high coefficient of friction relative to the material of rod 22 . Liner 62 is also conically shaped so as to fit within shell 60 .
[0029] Shell 60 and liner 62 have axial slots 64 , 66 , respectively extending from one end thereof to the other end thereof. In the exemplary embodiment shown, slots 64 and 66 are aligned one with the other. An axial length of friction cone 34 is slightly less than a length of an interior volume 68 defined by housing 30 so that friction cone 34 can move axially slightly in housing 30 , either toward or away from the narrow end of conically shaped volume 68 .
[0030] The operation of damper 10 will now be described with reference particularly to FIG. 2 . With damping assembly 20 in a substantially fixed position, such that housing 30 and cap 32 are relatively immovable, rod 22 is moved axially by apparatus to which it is operatively connected. For example, as cover 16 of console 12 is closed, a portion of the cover pushes against rods 22 of the two dampers 10 shown in FIG. 4 . As rod 22 moves downwardly in conically shaped housing 30 , moving in a direction from opening 50 in cap 32 toward opening 38 in housing 30 , friction cone 34 is dragged downwardly in conically shaped housing 30 . Accordingly, as each moves more deeply into the narrowed end of interior volume 68 , shell 60 and liner 62 are squeezed, narrowing slightly the openings defined by slits 64 , 66 . Greater clamping force is applied against rod 22 , and the friction of rod 22 against liner 62 resists axial movement of rod 22 . Accordingly, damping effect is provided on an object or thing that pushes against rod 22 , urging it downwardly in conical housing 30 .
[0031] When rod 22 is moved in an axial direction opposite to that just described, that is with rod 22 being moved from opening 38 of housing 30 toward opening 50 of cap 32 , friction cone 34 is moved upwardly within conical housing 30 . Accordingly, shell 60 and liner 62 are each allowed to expand slightly in the wider area of housing volume 68 , thereby increasing the widths of slots 64 and 66 . Clamping force against rod 22 is released, and minimal resistance to axial movement of rod 22 is provided.
[0032] Springs or other return means can be used to move rod 22 to a desired home location. For example, a spring can be used surrounding rod 22 between head 26 and cap 32 . Alternatively or conjunctively, a spring can be used operating against base 24 from beneath to move rod 22 upwardly. Other configurations also can be used. For example, the axial end of the rod, such as head 26 , can be secured to the device being controlled so that damper 10 provides damping in one direction and in the opposite direction provides little or no damping while rod 22 is being pulled to a desired start position.
[0033] Further, while described herein as having damping assembly 20 fixed and rod 22 movable, it should be understood that operation and function of damper 10 requires only relative movement between damping assembly 20 and rod 22 . Accordingly, in some installations and uses it may be advantageous for rod 22 to be fixed and for damping assembly 20 to move relative to rod 22 . As a further alternative, each damping assembly 20 and rod 22 can move either in opposite directions or in a same direction but at different speeds, such that relative movement occurs between damping assembly 20 and rod 22 .
[0034] It should be understood that the use of slits 64 , 66 and the enablement of axial movement of friction cone 34 in housing 30 enhance both the damping effect that can be generated from clamping forces of liner 62 against rod 22 , and the rapid disengagement of clamping force. However, a damper of the present invention can be configured and used with other means for applying a compressive or clamping force of inner liner 62 against rod 22 .
[0035] Variations and modifications of the foregoing are within the scope of the present invention. It is understood that the invention disclosed and defined herein extends to all alternative combinations of two or more of the individual features mentioned or evident from the text and/or drawings. All of these different combinations constitute various alternative aspects of the present invention. The embodiments described herein explain the best modes known for practicing the invention and will enable others skilled in the art to utilize the invention. The claims are to be construed to include alternative embodiments to the extent permitted by the prior art.
[0036] Various features of the invention are set forth in the following claims. | A linear damper includes a conical housing with a friction cone in the housing and a rod extending therethrough and axially moveable relative thereto. The friction cone is axially moveable in the housing and radially expandable and contractible to provide clamping force against a rod when the rod is moved in one axial direction and to relieve clamping force from the rod when the rod is moved in the opposite axial direction. | 5 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
Activated carbons are high porosity, high surface area materials used in industry for purification and chemical recovery operations as well as environmental remediation. Toxic metal contamination of various water sources is a significant problem in many parts of the United States. Activated carbons, which can be produced from a number of precursor materials including coal, wood and agricultural wastes, are now being actively utilized for remediation of this problem. Carbon production is an expanding industry in the United States, with a present production rate of over 300 million pounds a year and a growth rate of over 5% annually. The present invention relates to the development of specifically modified carbons from low-density agricultural waste products that possess enhanced adsorption properties with regard to the uptake of metal ions.
2. Description of the Prior Art
The production of carbon, in the form of charcoal, is an age-old art. Carbon, when produced by non-oxidative pyrolysis, is a relatively inactive material possessing a surface area limited to several square meters per gram. In order to enhance its activity, a number of protocols have been developed. These include chemical treatment of the carbonaceous material with various salts or acids prior to pyrolysis, or a reaction of the already pyrolyzed product with high temperature carbon dioxide or steam. Activated carbon is able to preferentially adsorb organic compounds and non-polar materials from either liquid or gaseous media. This property has been attributed to its possession of a form which conveys the desirable physical properties of high porosity and large surface area.
Usmani et al., in their paper entitled “Preparation and Liquid-Phase Characterization of Granular Activated-Carbon from Rice Husk”, [ Bioresource Technology, 48, (1994), pp.31-35] teach a process for the preparation of granular activated carbons from both high- and low-ash rice husks by the use of zinc chloride in the dual functions of an activating agent and a binder.
Morgan et al., in a publication entitled “Binders and Base Materials for Active Carbon”, [ Industrial and Engineering Chemistry , Vol. 38, No. 2, (1946), pp.219-227] disclose that various glucose carbohydrates differ markedly as materials for activated carbons; with dextrose behaving as a binder, cellulose as a base material, and starch having properties intermediate to either.
Arida et al., in “Production of High Quality Adsorbent Charcoal from Phil. Woods II. Granulated Activated Carbon”, [ Philippine Journal of Science , Vol. 121, No.1, pp.31-52], disclose the formation of good quality granulated activated carbons from coconut coir and ipil-ipil when utilizing molasses as a binder.
In Release No. 0483.95 from the Office of Communications, United States Department of Agriculture, (1995), it is disclosed that granular activated carbons effective in the removal of metals may be created from agricultural wastes such as sugarcane bagasse as well as the ground hulls of soybean, cottonseed and rice. The process disclosed utilized black strap molasses as a binding agent and includes the steps of creating charcoal from briquettes in an oxygen-free furnace at over 480° C. and subsequent roasting in the presence of steam at 700° C. to create enhanced surface area.
Rivera-Utrilla et al., in a paper entitled “Effect of Carbon-Oxygen and Carbon-Nitrogen Surface Complexes on the Adsorption of Cations by Activated Carbons”, [ Adsorption Science & Technology , (1986), 3, pp.293-302] details adsorption studies of Na + , Cs + , Ag + , Sr 2+ and Co 2+ utilizing carbons prepared from almond shells that had been activated with CO 2 at 850° C. for 8 hours and oxidized with air at 300° C. for 45 hours.
Molina-Sabio et al. in their paper entitled “Modification in Porous Texture and Oxygen Surface Groups of Activated Carbons by Oxidation”, [ Characterization of Porous Solids II, Rodriguez-Reinoso et al. (edit.), 1991, Elsevier Science Publishers B. V., Amsterdam] disclose that while oxidation treatment of fruit pits by either air or chemical means (HNO 3 or H 2 O 2 ) does not substantially modify the microporosity of the carbon structures created, the chemical nature of the carbon surface is changed considerably. No projected uses for these carbons are set forth.
Periasamy et al., in an article entitled “Process Development for Removal and Recovery of Cadmium from Wastewater by a Low-Cost Adsorbent: Adsorption Rates and Equilibrium Studies”, Ind. Eng. Chem. Res., 33, pp.317-320, (1994), show that at a concentration of 0.7 g/L, activated carbon produced from peanut hulls was able to achieve an almost quantitative removal of Cd(II) present at a concentration of 20 mg/L in an aqueous solution at a pH range of 3.5-9.5.
Moreno-Castilla et al., in an article entitled “Activated Carbon Surface Modifications by Nitric Acid, Hydrogen Peroxide, and Ammonium Peroxydisulfate Treatments” ( Langmuir, 1995, 11, pp.4386-4392), disclose the principle that acidic oxygen surface complexes are formed on activated carbons as a result of their treatment with either gas or solution phase oxidizing agents; and that inclusion of these complexes effect changes in the behavior of activated carbons when used either as adsorbents or catalysts.
While various methodologies for the creation of activated carbons exist, there remains a need for the creation of alternate viable and cost-effective products possessing enhanced adsorption characteristics.
SUMMARY OF THE INVENTION
We have now developed a novel process, which when carried out within specific operational parameters, effects the creation of activated carbons from low-density lignocellulosic agricultural waste possessing enhanced activity for the adsorption of metal ions. This method involves activation with either carbon dioxide or steam followed by atmospheric oxidation. It has now been discovered that the utilization of a relatively low temperature atmospheric oxidation step in conjunction with carbon dioxide or steam activation of the low-density agricultural waste carbon produces metallic binding oxygen functions in the mesopore and macropore regions of the carbon. Carbons produced by this process show metal adsorption capacities greater than that possessed by existing commercial carbons.
In accordance with this discovery, it is an object of the invention to provide a means for the creation of high quality metals-adsorbing carbons.
Another object is to provide activated carbon materials having high metal-adsorbing capacity.
Other objects and advantages of the invention will become readily apparent from the ensuing description.
DETAILED DESCRIPTION OF THE INVENTION
The present invention involves the creation of activated carbons from low-density lignocellulosic agricultural wastes, which possess enhanced adsorption ability with regard to metal cations. The carbon source for the activated carbons of the present invention may be any lignocellulosic material of plant origin having a combined cellulose and hemicellulose content greater than or equal to fifty percent (dry weight) and possessing a bulk density of less than 0.5 grams per cubic centimeter when measured for particles possessing a size range of 10 to 20 U.S. mesh. Exemplary materials include soybean hulls, rice hulls, cottonseed hulls, rice straw, wheat straw, oat straw, barley straw, sugarcane bagasse, corn cobs and peanut shells; with soybean hulls, peanut shells, rice straw and sugarcane bagasse being preferred.
According to the present invention, should a granular carbon product be desired, the low-density agricultural waste may optionally first be formed into pellets, briquettes, or extrudates by combination with a binder such as molasses, coal tar, or wood tar, before their conversion into a char. Relative ratios of the agricultural waste:binder may range from about 1:1 to about 6:1 (w/w), with a range of about 2:1 to about 4:1 being preferred. These formed precursor products are then carbonized in an inert atmosphere at temperatures ranging from about 700° C. to about 750° C. for a time ranging from about 1 hour to about 2 hours. The briquetted chars resulting from this process are then mechanically milled to a particle size no larger than about US 10 mesh so as to ensure their complete activation and oxidation under the conditions utilized in this invention. Chars resulting from pellets and extrudates, possessing maximal dimensions of 3 mm diameter and 10 mm length, are subjected to activation and oxidation without further size reduction. There is no effective limit to the minimum useable particle size, however, if a granular type product is desired, then it should be no smaller than about US 80 mesh.
Activation of the carbons is carried out by contact of the char material with carbon dioxide or steam under conditions and for sufficient time such that activation has been effected throughout the matrix of the particles of lignocellulosic material. The reaction is largely governed by transport phenomena involving diffusive processes. Particle size of the char material utilized affects the rate and degree of achievable activation. In order to achieve activation throughout the char material, particle size for the char should be no larger than about US 10 mesh, or possess cylindrical dimensions in excess of 3 mm diameter or 10 mm length. There is no effective limit to the minimum useable particle size, however, if a granular type product is desired, then it should be no smaller than about US 80 mesh. With this in mind, useable temperatures for the activation reaction may range from about 800° C. to about 950°C., and for times ranging from about 3 to about 12 hours in the case of granular carbon particles in the size range of US 10 mesh to US 80 mesh. For the case of smaller carbon particles, the skilled artisan would be able to readily determine the appropriate temperature and time conditions that would effect the activation process. The charring and activation reactors may be operated under a slight positive pressure to ensure that no atmospheric air takes part in these reactions. During activation, burn-offs ranging from about 20% to about 60% are envisioned as necessary for producing the products of the instant invention. The exact level of burnoff utilized is within the purview of the skilled artisan, and is dependent upon the specific materials and reaction conditions employed. “Burn-off” is defined as the weight loss of carbon source, as determined on a dry weight basis, that occurs during the activation process. Burn - off = Wt ba - Wt aa Wt ba × 100
where:
Wt ba =dry weight before activation
Wt as =dry weight after activation
Burn-off can only be between 0 and 100%. Too little burn-off (e.g., less than about 20%) is indicative of inadequate surface area and porosity development during activation. Burn-offs in excess of about 60% generally cause concomitant decreases in product surface area and functionality due to excessive pore enlargement. In addition, larger burn-offs become uneconomical due to the reduction in the amount of product produced.
The activated carbon is then oxidized by exposure to air at a temperature ranging from about 260° C. to about 400° C. for a time ranging from about 3 to about 6 hours. Oxidation of the carbon brings about the formation of polar functional groups on the surface of the meso- and macropores of the carbonized material. It is theorized that these are instrumental in the ability of the carbon to adsorb metal cations and anions such as those selected from the group consisting of Cu(II), Zn(II), Ni(II), Cd(II), Pb(II), Cr(III, VI), Hg(II), Fe(II, III), Au(I), Ag(I), V(IV,V), U(IV), Pu(IV), Cs(I), Sr(II), Al(III), Co(II), and Sn(II,IV).
The following examples are intended to further illustrate the invention and are not intended to limit the scope of the invention which is defined by the claims.
All percentages herein disclosed are by weight unless otherwise specified.
EXAMPLE 1
Unground soybean hulls were mixed with crude sugarcane molasses preheated to 60° C. in a 3:1 ratio (wt:wt). The mixture was allowed to dry until stiff, at which time it was pelletized into 3 mm diameter×6 mm length particles using a Kahl Model 14-175 pellet press (LCI Corp., Charlotte, N.C.). Conditions included an operating pressure of approximately 5000 pounds per square inch and a temperature of approximately 65° C. The pellets thus formed were allowed to cool to air temperature and dry in a vacuum oven at 30° C. The pellets were then placed in an inert atmosphere, Grieve Model BAF-8128 bench furnace with retort (Grieve Corporation, Round Lake, Ill.), and using a nitrogen atmosphere, heated to 210° C. for 30 minutes (to remove sorbed water) then increased to 750° C. for one hour. Activation was carried out by then further increasing the reactor temperature to 850° C. and injecting low pressure steam into the nitrogen atmosphere so as to create within the retort reactor a partial pressure of steam of about 0.1 bar. Steam flow into the retort was adjusted to give a residence time of 3-4 minutes per retort volume. The activation time was 12 hours. After activation, the materials were allowed to cool to 300° C. then exposed to flowing air whose residence time was 3-4 minutes per retort volume. Air exposure at 300° C. was for 4 hours. The resultant carbons were then washed in 0.05 M HCl to remove ash, then washed with distilled water until free of measurable chloride. They were dried at 110° C. for 6 hours.
The activated carbon pellets thus produced were utilized in the following test protocol. Char yield and percent burnoff were determined by the following formulas:
Char Yield (%)=(weight of pellets after heating to 750° C. but prior to activation/Original weight of soybean pellets)×100. Burn - off = Wt ba - Wt aa Wt ba × 100
where:
Wt ba =dry weight before activation
Wt aa =dry weight after activation
The BET surface area was determined by using a Micromeritics Gemini III 2375 surface area analyzer (Micromeritics Instrument Corp., Norcross, Ga.). Surface area measurements were obtained from N 2 adsorption at 77 degrees Kelvin and application of the Brunauer-Emmett-Teller (BET) gas adsorption method. Bulk density was determined by a tamping procedure using a 25 ml graduated glass cylinder as described by the American Water Works Association, 1991, Bulletin 604-90, AWWA Standard for Granular Activated Carbon. Adsorption capacity of the granular activated carbons with regard to copper was determined using a 0.01 M CuCl 2 solution buffered at pH 5.05 with 0.035 M Na acetate and 0.011 M acetic acid. This test used 0.5 g GAC in 50 ml solution with the solution stirred (250 rpm) for 24 hr at 23° C. Afterwards, an aliquot was drawn off in a disposable syringe and filtered through a Durapore membrane 0.22 μm filter (Millipore, Bedford, Mass.). The amount of Cu (II) remaining in solution was measured by inductively coupled plasma (ICP) spectrometry (Model PS 1, Leeman Labs Inc., Lowell, Mass.). The amount of Cu(II) adsorbed was determined from the difference between these readings.
Results:
Char Yield−25%
Burn-off−57%
BET surface area−700 m 2 /g
Bulk Density−0.35 g/cm 3
Copper adsorption−0.70-0.80 mmol Cu/g carbon
EXAMPLE 2
The activation atmosphere was a gas mixture with carbon dioxide at 13% (wt) and the remainder nitrogen gas. Flow volumes of retort reactor atmosphere should be adjusted to 15-20 reactor volumes per hour. Results were determined using methods and equipment identical to Example 1.
Results:
Char Yield−25%
Burn-off−22%
BET surface area−500 m 2 /g
Bulk Density−0.42 g/cm 3
Copper adsorption−0.80-0.85 mmol Cu/g carbon
EXAMPLE 3
Following the protocols of Example 1, soybean hull, peanut shell, sugarcane bagasse, and rice straw were made into briquettes comprising 1 part lignocellulosic material to 1 part crude sugarcane molasses (wt/wt). The briquettes were 5.7 cm in diameter and about 3 cm in thickness. They were made with a Carver Model C laboratory press (Fred S. Carver, Inc., Wabash, Ind.) utilizing a 5.7 cm inner diameter molding cylinder. An excess of the 1:1 lignocellulosic-molasses mixture was placed inside the mold and pressed for five minutes at 5000 psi. The briquettes were then charred as described in Example 1, then crushed and sieved to a size range of 10 to 20 US mesh. Activation, oxidation, wash, and dry steps were carried out according to the protocols of Example 1, except that activation was done at 800° C. temperature. A competitive adsorption study involving the five metals Cu, Cd, Ni, Pb, and Zn in a mixture were employed. These five metals are high frequency pollutants from municipalities and specific industries throughout the United States. The metal mixture contained 2.5 mM each of Pb(II) from Pb(NO 3 ) 2 , Cu(II) from CuCl 2 . 2H 2 O, Cd(II) from Cd(NO 3 ) 2 . 4H 2 O, Zn(II) from ZnCl 2 , and Ni(II) from Ni(NO 3 ) 2 .6H 2 O. The pH of the metal mixture was 5.0 (unbuffered). This assay used 0.5 g GAC in 50 ml of metal mixture. The mixture was stirred (250 rpm) for 2 hr at room temperature (23° C.). After stirring, an aliquot was drawn off in a disposable syringe and filtered through a Durapore Membrane 0.22 μm filter (Millipore, Bedford, Mass.). The aliquot was then analyzed for metals in the filtrate using inductively coupled plasma (ICP) spectrometry (Model PS 1, Leeman Labs Inc., Lowell, Mass.) and the amounts of metals adsorbed by the GACs were determined by difference. The BET surface area was determined by the protocol of Example 1. Comparisons were made between the metal adsorption properties of these carbons and several commercially available carbon materials; the results of which are illustrated in Table 1.
TABLE 1
Competitive Adsorption from a Solution
Containing 2.5 mM of Each Metal 1
BET Surface
-----μmoles of metal adsorbed per 1 g
Area
of GAC-----
GAC 2
(m 2 /g)
Ni 2+
Cu 2+
Zn 2+
Cd 2+
Pb 2+
Total
Calgon
783
0
97
0
30
113
240
GRC 3
Norit RO
827
0
117
0
11
67
195
3515 3
Norit
876
0
98
0
4
66
168
Vapure 3
Soybean
479
14
127
29
36
190
396
Hulls
Peanut
275
9
195
31
39
236
510
Shells
Sugarcane
162
7
132
21
29
206
395
Bagasse
Rice
460
2
144
24
32
174
376
Straw
1 0.5 g GAC in 50 mL solution, initial pH 5.0, 23° C., 2 hr. stirring.
2 Non-commercial GACs using agricultural by-products were charred as briquettes followed by crushing/sieving into granules for activation.
3 Commercial GACs which are Calgon GRC (Calgon Carbon Corporation, Pittsburgh, PA) and Norit RO 3515 and Vapure (American Norit Company, Inc., Atlanta, GA).
EXAMPLE 4
Rice straw, sugarcane bagasse, soybean hull, cottonseed hull and rice hull were made into granular activated carbons according to the protocols used in Example 3. Disclosed in Table 2 are results of a study using both a laboratory prepared solution of three metals for measurement of adsorption capacity and a sample of actual industrial wastewater for measurement of removal efficiency. The laboratory prepared solution was prepared using a metal mixture contained 1000 ppm each of Cu(II) from CuCl 2 .2H 2 O, Zn(II) from ZnCl 2 , and Ni(II) from Ni(NO 3 ) 2 .6H 2 O. The pH of the metal mixture was 5.0 (unbuffered). One gram of activated carbon was used with 100 mL of this solution and the solution was stirred for 2 hr at 250 rpm. The industrial wastewater, resulting from an electroplating process, contained 74.1 ppm Cu(II), 2.13 ppm Zn(II), and 41.0 ppm Ni(II) at pH 4.8. One gram of granular activated carbon was placed in a beaker along with 20 mL of the metal containing wastewater and stirred for 2 hr at 250 rpm with a Teflon™ stirring bar. For both the laboratory prepared wastewater and the actual industrial wastewater, an aliquot was removed after stirring, filtered, and analyzed identical to the protocol in Example 3. Table 2 presents the results, which illustrate the high capacity and high removal efficiencies of the instantly claimed carbons with regard to capacity and removal of metals as compared to existing commercial products.
TABLE 2
GAC Capacity, Removal Efficiency, Both by Competitive
Adsorption of Cu, Zn, and Ni
Adsorption
Percent Removal from Metal
Capacity 1
Plating Wastewater 2
GAC
(meq/g)
Cu (II)
Zn (II)
Ni (II)
Calgon
0.4
99.8
100
97.6
GRC 3
Darco LI
0.1
94.3
40.5
24.3
(12 × 20) 3
Rice straw
1.1
99.9
100
99.5
Sugarcane
0.7
99.9
100
99.3
Bagasse
Soybean hulls
1.3
99.9
100
99.5
Cottonseed
0.7
98.4
100
94.0
hulls
Rice hulls
0.5
99.9
100
96.0
1 By use of the laboratory prepared metal solution described in the narrative above.
2 Industrial wastewater from Albuquerque, NM, and methods described in the narrative above.
Commercial GACs were Calgon GRC (Calgon Carbon Corporation, Pittsburgh, Pa.), and Darco LI (12×20) (American Norit Company, Inc., Atlanta, Ga.).
EXAMPLE 5
Soybean and cottonseed hulls were used without grinding and made into pellets as described in Example 1. The molasses-hull ratio was 1:3(wt:wt). These pellets were made into granular activated carbons using the processes described in Example 1. Metal adsorption capacity was determined by copper (II) adsorption exactly using the parameters described in Example 1, except the copper concentration was 0.02 M. A commercial GAC, Calgon GRC (Calgon Carbon Company, Pittsburgh, Pa.) was similarly tested as a comparison. Results, based on the average of three replicate runs, were as follows:
Results:
Calgon PCB copper adsorption−0.45 mmol Cu/g carbon
Soybean hull based GAC copper adsorption−0.94 mmol Cu/g carbon
Cottonseed hull based GAC copper adsorption−0.56 mmol Cu/g carbon. | Activated carbons derived from low-density lignocellulosic agricultural waste, and for use in absorption of metals, are prepared utilizing carbon dioxide or steam activation at 800° C. to 950° C. for 3 to 12 hours and subsequent oxidation with air at 260° C. to 400° C. for 3 to 6 hours. Granular carbons are formed by the inclusion of a preliminary two-step process involving the admixture of a binder selected from molasses, coal tar or wood tar to form pellets, briquettes or extrudates and converting them into a char under an inert atmosphere at 700° C. to 750° C. for 1 to 2 hours. | 2 |
RELATED APPLICATIONS
[0001] This application is a continuation of U.S. Ser. No. 10/060,556 filed Jan. 30, 2002, which is a continuation of U.S. Ser. No. 09/803,647 filed Mar. 9, 2001, now U.S. Pat. No. 6,433,026, which is a continuation of U.S. Ser. No. 09/532,984 filed Mar. 22, 2000, which is a continuation of U.S. Ser. No. 09/388,876 filed Sep. 2, 1999, now U.S. Pat. No. 6,066,678, which is a continuation of U.S. Ser. No. 09/288,357 filed Apr. 8, 1999, now U.S. Pat. No. 5,981,693, which is a continuation of U.S. Ser. No. 09/129,286 filed Aug. 5, 1998, now U.S. Pat. No. 5,917,007, which is a continuation of U.S. Ser. No. 08/910,692 filed Aug. 13, 1997, now abandoned, which is a divisional of U.S. Ser. No. 08/460,980 filed on Jun. 5, 1995, now U.S. Pat. No. 5,679,717, which is a continuation-in-part of U.S. Ser. No. 08/258,431 filed Jun. 10, 1994, now abandoned, the entire teachings of all of which are incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] This invention relates to removing bile salts from a patient.
[0003] Salts of bile acids act as detergents to solubilize and consequently aid in digestion of dietary fats. Bile acids are precursors to bile salts, and are derived from cholesterol. Following digestion, bile acids can be passively absorbed in the jejunum, or, in the case of conjugated primary bile acids, reabsorbed by active transport in the ileum. Bile acids which are not reabsorbed by active transport are deconjugated and dehydroxylated by bacterial action in the distal ileum and large intestine.
[0004] Reabsorption of bile acids from the intestine conserves lipoprotein cholesterol in the bloodstream. Conversely, blood cholesterol level can be diminished by reducing reabsorption of bile acids.
[0005] One method of reducing the amount of bile acids that are reabsorbed is oral administration of compounds that sequester the bile acids and cannot themselves be absorbed. The sequestered bile acids consequently either decompose by bacterial action or are excreted.
[0006] Many bile acid sequestrants, however, bind relatively hydrophobic bile acids more avidly than conjugated primary bile acids, such as conjugated cholic and chenodeoxycholic acids. Further, active transport in the ileum causes substantial portions of sequestered conjugated primary bile acids to be desorbed and to enter the free bile acid pool for reabsorption. In addition, the volume of sequestrants that can be ingested safely is limited. As a result, the effectiveness of sequestrants to diminish blood cholesterol levels is also limited.
[0007] Sequestering and removing bile salts (e.g., cholate, glycocholate, glycochenocholate, taurocholate, and deoxycholate salts) in a patient can be used to reduce the patient's cholesterol level. Because the biological precursor to bile salt is cholesterol, the metabolism of cholesterol to make bile salts is accompanied by a simultaneous reduction in the cholesterol in the patient.
[0008] Cholestyramine, a polystyrene/divinylbenzene ammonium ion exchange resin, when ingested, removes bile salts via the digestive tract. This resin, however, is unpalatable, gritty and constipating. Resins which avoid (totally or partially) these disadvantages and/or possess improved bile salt sequestration properties are needed.
SUMMARY OF THE INVENTION
[0009] The invention relates to the discovery that a new class of ion exchange resins have improved bile salt sequestration properties and little to no grittiness, thereby improving the palatability of the composition.
[0010] The resins comprise cross-linked polyamines which are characterized by one or more hydrophobic substituents and, optionally, one or more quaternary ammonium containing substituents.
[0011] In general, the invention features resins and their use in removing bile salts from a patient that includes administering to the patient a therapeutically effective amount of the reaction product of:
[0012] (a) one or more crosslinked polymers, salts and copolymers thereof characterized by a repeat unit selected from the group consisting essentially of:
[0013] where n is a positive integer and each R, independently, is H or a substituted or unsubstituted alkyl group (e.g., C 1 -C 8 alkyl); and
[0014] (b) at least one alkylating agent. The reaction product is characterized in that: (i) at least some of the nitrogen atoms in the repeat units are unreacted with the alkylating agent; (ii) less than 10 mol % of the nitrogen atoms in the repeat units that react with the alkylating agent form quaternary ammonium units; and (iii) the reaction product is preferably non-toxic and stable once ingested.
[0015] Suitable substituents include quaternary ammonium, amine, alkylamine, dialkylamine, hydroxy, alkoxy, halogen, carboxamide, sulfonamide and carboxylic acid ester, for example.
[0016] In preferred embodiments, the polyamine of compound (a) of the reaction product is crosslinked by means of a multifunctional crosslinking agent, the agent being present in an amount from about 0.5-25% (more preferably about 2.5-20% (most preferably 1-10%)) by weight, based upon total weight or monomer plus crosslinking agent. A preferred crosslinking agent is epichlorohydrin because of its high availability and low cost. Epichlorohydrin is also advantageous because of it's low molecular weight and hydrophilic nature, increasing the water-swellability and gel properties of the polyamine.
[0017] The invention also features compositions based upon the above-described reaction products.
[0018] The invention provides an effective treatment for removing bile salts from a patient (and thereby reducing the patient's cholesterol level). The compositions are non-toxic and stable when ingested in therapeutically effective amounts.
[0019] Other features and advantages will be apparent from the following description of the preferred embodiments thereof and from the claims.
DETAILED DESCRIPTION OF THE INVENTION
[0020] Compositions
[0021] Preferred reaction products include the products of one or more crosslinked polymers having the formulae set forth in the Summary of the Invention, above, and one or more alkylating agents. The polymers are crosslinked. The level of crosslinking makes the polymers completely insoluble and thus limits the activity of the alkylated reaction product to the gastrointestinal tract only. Thus, the compositions are non-systemic in their activity and will lead to reduced side-effects in the patient.
[0022] By “non-toxic” it is meant that when ingested in therapeutically effective amounts neither the reaction products nor any ions released into the body upon ion exchange are harmful. Cross-linking the polymer renders the polymer substantially resistant to absorption. When the polymer is administered as a salt, the cationic counterions are preferably selected to minimize adverse effects on the patient, as is more particularly described below.
[0023] By “stable” it is meant that when ingested in therapeutically effective amounts the reaction products do not dissolve or otherwise decompose in vivo to form potentially harmful by-products, and remain substantially intact so that they can transport material out of the body.
[0024] By “salt” it is meant that the nitrogen group in the repeat unit is protonated to create a positively charged nitrogen atom associated with a negatively charged counterion.
[0025] By “alkylating agent” it is meant a reactant which, when reacted with the crosslinked polymer, causes an alkyl group or derivative thereof (e.g., a substituted alkyl, such as an aralkyl, hydroxyalkyl, alkylammonium salt, alkylamide, or combination thereof) to be covalently bound to one or more of the nitrogen atoms of the polymer.
[0026] One example of preferred polymer is characterized by a repeat unit having the formula
[0027] or a salt or copolymer thereof; wherein x is zero or an integer between about 1 to 4.
[0028] A second example of a preferred polymer is characterized by a repeat unit having the formula
(NH—CH 2 CH 2 ) n (6)
[0029] or a salt or copolymer thereof.
[0030] A third example of a preferred polymer is characterized by a repeat unit having the formula
(NH—CH 2 CH 2 —NH—CH 2 CH 2 —NH—CH 2 CHOH—CH 2 ) n (7)
[0031] or a salt or copolymer thereof.
[0032] The polymers are preferably crosslinked prior to alkylation. Examples of suitable crosslinking agents include acryloyl chloride, epichlorohydrin, butanedioldiglycidyl ether, ethanedioldiglycidyl ether, and dimethyl succinate. The amount of crosslinking agent is typically between 0.5 and 25 weight %, based upon combined weight of crosslinking agent and monomer, with 2.5-20%, or 1-10%, being preferred.
[0033] Typically, the amount of crosslinking agent that is reacted with the amine polymer is sufficient to cause reaction of between about 0.5 and twenty percent of the amines. In a preferred embodiment, between about 0.5 and six percent of the amine groups react with the crosslinking agent.
[0034] Crosslinking of the polymer can be achieved by reacting the polymer with a suitable crosslinking agent in an aqueous caustic solution at about 25° C. for a period of time of about eighteen hours to thereby form a gel. The gel is then combined with water and blended to form a particulate solid. The particulate solid can then be washed with water and dried under suitable conditions, such as a temperature of about 50° C. for a period of time of about eighteen hours.
[0035] Alkylation involves reaction between the nitrogen atoms of the polymer and the alkylating agent (which may contain additional nitrogen atoms, e.g., in the form of amido or ammonium groups). In addition, the nitrogen atoms which do react with the alkylating agent(s) resist multiple alkylation to form quaternary ammonium ions such that less than 10 mol % of the nitrogen atoms form quaternary ammonium ions at the conclusion of alkylation.
[0036] Preferred alkylating agents have the formula RX where R is a C 1 -C 20 alkyl (preferably C 4 -C 20 ), C 1 -C 20 hydroxy-alkyl (preferably C 4 -C 20 hydroxyalkyl), C 7 -C 20 aralkyl, C 1 -C 20 alkylammonium (preferably C 4 -C 20 alkyl ammonium), or C 1 -C 20 alkylamido (preferably C 4 -C 20 alkyl amido) group and X includes one or more electrophilic leaving groups. By “electrophilic leaving group” it is meant a group which is displaced by a nitrogen atom in the crosslinked polymer during the alkylation reaction. Examples of preferred leaving groups include halide, epoxy, tosylate, and mesylate group. In the case of, e.g., epoxy groups, the alkylation reaction causes opening of the three-membered epoxy ring.
[0037] Examples of preferred alkylating agents include a C 1 -C 20 alkyl halide (e.g., an n-butyl halide, n-hexyl halide, n-octyl halide, n-decyl halide, n-dodecyl halide, n-tetradecyl halide, n-octadecyl halide, and combinations thereof); a C 1 -C 20 dihaloalkane (e.g., a 1,10-dihalodecane); a C 1 -C 20 hydroxyalkyl halide (e.g., an 11-halo-1-undecanol); a C 1 -C 20 aralkyl halide (e.g., a benzyl halide); a C 1 -C 20 alkyl halide ammonium salt (e.g., a (4-halobutyl) trimethylammonium salt, (6-halohexyl)trimethyl-ammonium salt, (8-halooctyl)trimethylammonium salt, (10-halodecyl)trimethylammonium salt, (12-halododecyl)-trimethylammonium salts and combinations thereof); a C 1 -C 20 alkyl epoxy ammonium salt (e.g., a (glycidylpropyl)-trimethylammonium salt); and a C 1 -C 20 epoxy alkylamide (e.g., an N-(2,3-eoxypropane)butyramide, N-(2,3-epoxypropane) hexanamide, and combinations thereof).
[0038] It is particularly preferred to react the polymer with at least two alkylating agents, added simultaneously or sequentially to the polymer. In one preferred example, one of the alkylating agents has the formula RX where R is a C 1 -C 20 alkyl group and X includes one or more electrophilic leaving groups (e.g., an alkyl halide), and the other alkylating agent has the formula R′X where R′ is a C 1 -C 20 alkyl ammonium group and X includes one or more electrophilic leaving groups (e.g., an alkyl halide ammonium salt).
[0039] In another preferred example, one of the alkylating agents has the formula RX where R is a C 1 -C 20 alkyl group and X includes one or more electrophilic leaving groups (e.g., an alkyl halide), and the other alkylating agent has the formula R′X where R′ is a C 1 -C 20 hydroxyalkyl group and X includes one or more electrophilic leaving groups (e.g., a hydroxy alkyl halide).
[0040] In another preferred example, one of the alkylating agents is a C 1 -C 20 dihaloalkane and the other alkylating agent is a C 1 -C 20 alkylammonium salt.
[0041] The reaction products may have fixed positive charges, or may have the capability of becoming charged upon ingestion at physiological pH. In the latter case, the charged ions also pick up negatively charged counterions upon ingestion that can be exchanged with bile salts. In the case of reaction products having fixed positive charges, however, the reaction product may be provided with one or more exchangeable counterions. Examples of suitable counterions include Cl − , Br − , CH 3 OSO 3 − , HSO 4 − , SO 4 2− , HCO 3 − , CO 3 − , acetate, lactate, succinate, propionate, butyrate, ascorbate, citrate, maleate, folate, an amino acid derivative, a nucleotide, a lipid, or a phospholipid. The counterions may be the same as, or different from, each other. For example, the reaction product may contain two different types of counterions, both of which are exchanged for the bile salts being removed. More than one reaction product, each having different counterions associated with the fixed charges, may be administered as well.
[0042] The alkylating agent can be added to the cross-linked polymer at a molar ratio between about 0.05:1 to 4:1, for example, the alkylating agents can be preferably selected to provide hydrophobic regions and hydrophilic regions.
[0043] The amine polymer is typically alkylated by combining the polymer with the alkylating agents in an organic solvent. The amount of first alkylating agent combined with the amine polymer is generally sufficient to cause reaction of the first alkylating agent with between about 5 and 75 of the percent of amine groups on the amine polymer that are available for reaction. The amount of second alkylating agent combined with the amine polymer and solution is generally sufficient to cause reaction of the second alkylating agent with between about 5 and about 75 of the amine groups available for reaction on the amine polymer. Examples of suitable organic solvents include methanol, ethanal, isopropanol, acetonitrile, DMF and DMSO. A preferred organic solvent is methanol.
[0044] In one embodiment, the reaction mixture is heated over a period of about forty minutes to a temperature of about 65° C., with stirring. Typically, an aqueous sodium hydroxide solution is continuously added during the reaction period. Preferably, the reaction period at 65° C. is about eighteen hours, followed by gradual cooling to a room temperature of about 25° C. over a period of about four hours. The resulting reaction product is then filtered, resuspended in methanol, filtered again, and then washed with a suitable aqueous solution, such as two molar sodium chloride,and then with deionized water. The resultant solid product is then dried under suitable conditions, such as at a temperature of about 60° C. in an air-drying oven. The dried solid can then be subsequently processed. Preferably, the solid is ground and passed through an 80 mesh sieve.
[0045] In a particularly preferred embodiment of the invention, the amine polymer is a crosslinked poly(allylamine), wherein the first substituent includes a hydrophobic decyl moiety, and the second amine substituent includes a hexyltrimethylammonium. Further, the particularly preferred crosslinked poly(allylamine) is crosslinked by epichlorohydrin that is present in a range of between about two and six percent of the amines available for reaction with the epichlorohydrin.
[0046] The invention will now be described more specifically by the examples.
EXAMPLES
A. Polymer Preparation
[0047] 1. Preparation of Poly(vinylamine)
[0048] The first step involved the preparation of ethylidenebisacetamide. Acetamide (118 g), acetaldehyde (44.06 g), copper acetate (0.2 g), and water (300 mL) were placed in a 1 L three neck flask fitted with condenser, thermometer, and mechanical stirred. Concentrated HCl (34 mL) was added and the mixture was heated to 45-50° C. with stirring for 24 hours. The water was then removed in vacuo to leave a thick sludge which formed crystals on cooling to 5° C. Acetone (200 mL) was added and stirred for a few minutes, after which the solid was filtered off and discarded. The acetone was cooled to 0° C. and solid was filtered off. This solid was rinsed in 500 mL acetone and air dried 18 hours to yield 31.5 g of ethylidenebis-acetamide.
[0049] The next step involved the preparation of vinylacetamide from ethylidenebisacetamide. Ethylidenebisacetamide (31.05 g), calcium carbonate (2 g) and celite 541 (2 g) were placed in a 500 mL three neck flask fitted with a thermometer, a mechanical stirred, and a distilling heat atop a Vigroux column. The mixture was vacuum distilled at 24 mm Hg by heating the pot to 180-225° C. Only a single fraction was collected (10.8 g) which contained a large portion of acetamide in addition to the product (determined by NMR). This solid product was dissolved in isopropanol (30 mL) to form the crude vinylacetamide solution used for polymerization.
[0050] Crude vinylacetamide solution (15 mL), divinylbenzene (1 g, technical grade, 55% pure, mixed isomers), and AIBN (0.3 g) were mixed and heated to reflux under a nitrogen atmosphere for 90 minutes, forming a solid precipitate. The solution was cooled, isopropanol (50 mL) was added, and the solid was collected by centrifugation. The solid was rinsed twice in isopropanol, once in water, and dried in a vacuum oven to yield 0.8 g of poly(vinylacetamide), which was used to prepare poly(vinylamine as follows).
[0051] Poly(vinylacetamide) (0.79 g) was placed in a 100 mL one neck flask containing water (25 mL) and conc. HCl (25 mL). The mixture was refluxed for 5 days, after which the solid was filtered off, rinsed once in water, twice in isopropanol, and dried in a vacuum oven to yield 0.77 g of product. Infrared spectroscopy indicated that a significant amount of the amide (1656 cm −1 ) remained and that not much amine (1606 cm −1 ) was formed. The product of this reaction (˜0.84 g) was suspended in NaOh (46 g) and water (46 g) and heated to boiling (˜140° C.). Due to foaming the temperature was reduced and maintained at ˜100° C. for 2 hours. Water (100 mL) was added and the solid collected by filtration. After rinsing once in water the solid was suspended in water (500 mL) and adjusted to pH 5 with acetic acid. The solid was again filtered off, rinsed with water, then isopropanol, and dried in a vacuum oven to yield 0.51 g of product. Infrared spectroscopy indicated that significant amine had been formed.
[0052] 2. Preparation of Poly(ethyleneimine)
[0053] Polyethyleneimine (120 g of a 50% aqueous solution; Scientific Polymer Products) was dissolved in water (250 mL). Epichlorohydrin (22.1 mL) was added dropwise. The solution was heated to 60° C. for 4 hours, after which it had gelled. The gel was removed, blended with water (1.5 L) and the solid was filtered off, rinsed three times with water (3 L) and twice with isopropanol (3 L), and the resulting gel was dried in a vacuum oven to yield 81.2 g of the title polymer.
[0054] 3. Preparation of Poly(allylamine) hydrochloride
[0055] To a 2 liter, water-jacketed reaction kettle equipped with (1) a condenser topped with a nitrogen gas inlet, (2) a thermometer, and (3) a mechanical stirrer was added concentrated hydrochloric acid (360 mL). The acid was cooled to 5° C. using circulating water in the jacket of the reaction kettle (water temperature=0° C.). Allylamine (328.5 mL, 250 g) was added dropwise with stirring while maintaining the reaction temperature at 5-10° C. After addition was complete, the mixture was removed, placed in a 3 liter one-neck flask, and 206 g of liquid was removed by rotary vacuum evaporation at 60° C. Water (20 mL) was then added and the liquid was returned to the reaction kettle. Azobis(amidinopropane) dihydrochloride (0.5 g) suspended in 11 mL of water was then added. The resulting reaction mixture was heated to 50° C. under a nitrogen atmosphere with stirring for 24 hours. Additional azobis(amidinopropane) dihydrochloride (5 mL) suspended in 11 mL of water was then added, after which heating and stirring were continued for an additional 44 hours.
[0056] At the end of this period, distilled water (100 mL) was added to the reaction mixture and the liquid mixture allowed to cool with stirring. The mixture was then removed and placed in a 2 liter separatory funnel, after which it was added dropwise to a stirring solution of methanol (4 L), causing a solid to form. The solid was removed by filtration, re-suspended in methanol (4 L), stirred for 1 hour, and collected by filtration. The methanol rinse was then repeated one more time and the solid dried in a vacuum oven to afford 215.1 g of poly(allylamine) hydrochloride as a granular white solid.
[0057] 4. Preparation of Poly(allylamine) hydrochloride Crosslinked with epichlorohydrin
[0058] To a 5 gallon vessel was added poly(allylamine) hydrochloride prepared as described in Example 3 (1 kg) and water (4 L). The mixture was stirred to dissolve the hydrochloride and the pH was adjusted by adding solid NaOH (284 g). The resulting solution was cooled to room temperature, after which epichlorohydrin crosslinking agent (50 mL) was added all at once with stirring. The resulting mixture was stirred gently until it gelled (about 35 minutes). The crosslinking reaction was allowed to proceed for an additional 18 hours at room temperature, after which the polymer gel was removed and placed in portions in a blender with a total of 10 L of water. Each portion was blended gently for about 3 minutes to form coarse particles which were then stirred for 1 hour and collected by filtration. The solid was rinsed three times by suspending it in water (10 L, 15 L, 20 L), stirring each suspension for 1 hour, and collecting the solid each time by filtration. The resulting solid was then rinsed once by suspending it in isopropanol (17 L), stirring the mixture for 1 hour, and then collecting the solid by filtration, after which the solid was dried in a vacuum oven at 50° C. for 18 hours to yield about 677 g of the cross linked polymer as a granular, brittle, white solid.
[0059] 5. Preparation of Poly(allylamine) hydrochloride Crosslinked with butanedioldiglycidyl ether
[0060] To a 5 gallon plastic bucket was added poly(allylamine) hydrochloride prepared as described in Example 3 (500 g) and water (2 L). The mixture was stirred to dissolve the hydrochloride and the pH was adjusted to 10 by adding solid NaOH (134.6 g). The resulting solution was cooled to room temperature in the bucket, after which 1,4-butanedioldiglycidyl ether crosslinking agent (65 mL) was added all at once with stirring. The resulting mixture was stirred gently until it gelled (about 6 minutes). The crosslinking reaction was allowed to proceed for an additional 18 hours at room temperature, after which the polymer gel was removed and dried in a vacuum oven at 75° C. for 24 hours. The dry solid was then ground and sieved to −30 mesh, after which it was suspended in 6 gallons of water and stirred for 1 hour. The solid was then filtered off and the rinse process repeated two more times. The resulting solid was then air dried for 48 hours, followed by drying in a vacuum oven at 50° C. for 24 hours to yield about 415 g of the crosslinked polymer as a white solid.
[0061] 6. Preparation of Poly(allylamine) hydrochloride Crosslinked with ethanedioldiglycidyl ether
[0062] To a 100 mL beaker was added poly(allylamine) hydrochloride prepared as described in Example 3 (10 g) and water (40 mL). The mixture was stirred to dissolve the hydrochloride and the pH was adjusted to 10 by adding solid NaOH. The resulting solution was cooled to room temperature in the beaker, after which 1,2-ethanedioldiglycidyl ether crosslinking agent (2.0 mL) was added all at once with stirring. The resulting mixture was stirred gently until it gelled (about 4 minutes). The crosslinking reaction was allowed to proceed for an additional 18 hours at room temperature, after which the polymer gel was removed and blended in 500 mL of methanol. The solid was then filtered off and suspended in water (500 mL). After stirring for 1 hour, the solid was filtered off and the rinse process repeated. The resulting solid was rinsed twice in isopropanol (400 mL) and then dried in a vacuum oven at 50° C. for 24 hours to yield 8.7 g of the crosslinked polymer as a white solid.
[0063] 7. Preparation of Poly(allylamine) hydrochloride Crosslinked with dimethylsuccinate
[0064] To a 500 mL round bottom flask was added poly(allylamine) hydrochloride prepared as described in Example 3 (10 g), methanol (100 mL), and triethylamine (10 mL). The mixture was stirred and dimethylsuccinate crosslinking agent (1 mL) was added. The solution was heated to reflux and the stirring discontinued after 30 minutes. After 18 hours, the solution was cooled to room temperature, and the solid filtered off and blended in 400 mL of isopropanol. The solid was then filtered off and suspended in water (1 L). After stirring for 1 hour, the solid was filtered off and the rinse process repeated two more times. The solid was then rinsed once in isopropanol (800 mL) and dried in a vacuum oven at 50° C. for 24 hours to yield 5.9 g of the crosslinked polymer as a white solid.
[0065] 8. Preparation of Poly(ethyleneimine) Crosslinked with acryloyl chloride
[0066] Into a 5 L three neck flask equipped with a mechanical stirred, a thermometer, and an addition funnel was added poly(ethyleneimine) (510 g of a 50% aqueous solution, equivalent to 255 g of dry polymer) and isopropanol (2.5 L). Acryloyl chloride crosslinking agent (50 g) was added dropwise through the addition funnel over a 35 minute period while maintaining the temperature below 29° C. The solution was then heated to 60° C. with stirring for 18 hours, after which the solution was cooled and the solid immediately filtered off. The solid was then washed three times by suspending it in water (2 gallons), stirring for 1 hour, and filtering to recover the solid. Next, the solid was rinsed once by suspending it in methanol (2 gallons), stirring for 30 minutes, and filtering to recover the solid. Finally, the solid was rinsed in isopropanol as in Example 7 and dried in a vacuum oven at 50° C. for 18 hours to yield 206 g of the crosslinked polymer as a light orange granular solid.
[0067] 9. Alkylation of Poly(allylamine) Crosslinked with butanedioldiglydicyl ether with 1-iodooctane alkylating Agent
[0068] Poly(allylamine) crosslinked with butanedioldiglycidyl ether prepared as described in Example 5 (5 g) was suspended in methanol (100 mL) and sodium hydroxide (0.2 g) was added. After stirring for 15 minutes, 1-iodooctane (1.92 mL) was added and the mixture stirred at 60° C. for 20 hours. The mixture was then cooled and the solid filtered off. Next, the solid was washed by suspending it in isopropanol (500 mL), after which it was stirred for 1 hour and then collected by filtration. The wash procedure was then repeated twice using aqueous sodium chloride (500 mL of a 1 M solution), twice with water (500 mL), and once with isopropanol (500 mL) before drying in a vacuum oven at 50° C. for 24 hours to yield 4.65 g of alkylated product.
[0069] The procedure was repeated using 2.88 mL of 1-iodooctane to yield 4.68 g of alkylated product.
[0070] 10. Alkylation of Poly(allylamine) Crosslinked with epichlorohydrin with 1-iodooctane alkylating Agent
[0071] Poly(allylamine) crosslinked with epichlorohydrin prepared as described in Example 4 (5 g) was alkylated according to the procedure described in Example 9 except that 3.84 mL of 1-iodooctane was used. The procedure yielded 5.94 g of alkylated product.
[0072] 11. Alkylation of Poly(allylamine) Crosslinked with epichlorohydrin with 1-iodooctadecane alkylating Agent
[0073] Poly(allylamine) crosslinked with epichlorohydrin prepared as described in Example 4 (10 g) was suspended in methanol (100 mL) and sodium hydroxide (0.2 g) was added. After stirring for 15 minutes, 1-iodooctadecane (8.1 g) was added and the mixture stirred at 60° C. for 20 hours. The mixture was then cooled and the solid filtered off. Next, the solid was washed by suspending it in isopropanol (500 mL), after which it was stirred for 1 hour and then collected by filtration. The wash procedure was then repeated twice using aqueous sodium chloride (500 mL of a 1 M solution), twice with water (500 mL), and once with isopropanol (500 mL) before drying in a vacuum oven at 50° C. for 24 hours to yield 9.6 g of alkylated product.
[0074] 12. Alkylation of Poly(allylamine) Crosslinked with butanedioldiglycidyl ether with 1-iodododecane alkylating Agent
[0075] Poly(allylamine) crosslinked with butanedioldiglycidyl ether prepared as described in Example 5 (5 g) was alkylated according to the procedure described in Example 11 except that 2.47 mL of 1-iodododecane was used. The procedure yielded 4.7 g of alkylated product.
[0076] 13. Alkylation of Poly(allylamine) Crosslinked with butanedioldiglycidyl ether with benzyl bromide alkylating Agent
[0077] Poly(allylamine) crosslinked with butanedioldiglycidyl ether prepared as described in Example 5 (5 g) was alkylated according to the procedure described in Example 11 except that 2.42 mL of benzyl bromide was used. The procedure yielded 6.4 g of alkylated product.
[0078] 14. Alkylation of Poly(allylamine) Crosslinked with epichlorohydrin with benzyl bromide alkylating Agent
[0079] Poly(allylamine) crosslinked with epichlorohydrin prepared as described in Example 4 (5 g) was alkylated according to the procedure described in Example 11 except that 1.21 mL of benzyl bromide was used. The procedure yielded 6.6 g of alkylated product.
[0080] 15. Alkylation of Poly(allylamine) Crosslinked with epichlorohydrin with 1-iododecane alkylating Agent
[0081] Poly(allylamine) crosslinked with epichlorohydrin prepared as described in Example 4 (20 g) was alkylated according to the procedure described in Example 11 except that 7.15 g of 1-iododecane and 2.1 g of NaOH were used. The procedure yielded 20.67 g of alkylated product.
[0082] 16. Alkylation of Poly(allylamine) Crosslinked with epichlorohydrin with 1-iodobutane alkylating Agent
[0083] Poly(allylamine) crosslinked with epichlorohydrin prepared as described in Example 4 (20 g) was alkylated according to the procedure described in Example 11 except that 22.03 g of 1-iodobutane and 8.0 g of NaOH were used. The procedure yielded 24.0 g of alkylated product.
[0084] The procedure was also followed using 29.44 g and 14.72 g of 1-iodobutane to yield 17.0 g and 21.0 g, respectively, of alkylated product.
[0085] 17. Alkylation of Poly(allylamine) Crosslinked with epichlorohydrin with 1-iodotetradecane alkylating Agent
[0086] Poly(allylamine) crosslinked with epichlorohydrin prepared as described in Example 4 (5 g) was alkylated according to the procedure described in Example 11 except that 2.1 mL of 1-iodotetradecane was used. The procedure yielded 5.2 g of alkylated product.
[0087] The procedure was also followed using 6.4 mL of 1-iodotetradecane to yield 7.15 g of alkylated product.
[0088] 18. Alkylation of Poly(allylamine) Crosslinked with epichlorohydrin with 1-iodooctane alkylating Agent
[0089] Poly(allylamine) crosslinked with epichlorohydrin prepared as described in Example 8 (5 g) was alkylated according to the procedure described in Example 11 except that 1.92 mL of 1-iodooctane was used. The procedure yielded 5.0 g of alkylated product.
[0090] 19. Alkylation of a Copolymer of diethylene triamine and epichlorohydrin with 1-iodooctane alkylating Agent
[0091] A copolymer of diethylene triamine and epichlorohydrin (10 g) was alkylated according to the procedure described in Example 11 except that 1.92 mL of 1-iodooctane was used. The procedure yielded 5.3 g of alkylated product.
[0092] 20. Alkylation of Poly(allylamine) Crosslinked with epichlorohydrin with 1-iodododecane and glycidyl-propyltrimethylammonium chloride alkylating Agents
[0093] Poly(allylamine) crosslinked with epichlorohydrin prepared as described in Example 4 (20 g) was alkylated according to the procedure described in Example 11 except that 23.66 g of 1-iodododecane, 6.4 g of sodium hydroxide, and 500 mL of methanol were used. 24 grams of the alkylated product was then reacted with 50 g of 90% glycidylpropyltrimethylammonium chloride in methanol (1 L). The mixture was stirred at reflux for 24 hours, after which it was cooled to room temperature and washed successively with water (three times using 2.5 L each time). Vacuum drying afforded 22.4 g of dialkylated product.
[0094] Dialkylated products were prepared in an analogous manner by replacing 1-iodododecane with 1-iododecane and 1-iodooctadecane, respectively, followed by alkylation with glycidylpropyltrimethylammonium chloride.
[0095] 21. Alkylation of Poly(allylamine) Crosslinked with epichlorohydrin with glycidylpropyltrimethylammonium chloride alkylating Agent
[0096] Poly(allylamine) crosslinked with epichlorohydrin prepared as described in Example 4 (5 g) was reacted with 11.63 g of 90% glycidylpropyltrimethylammonium chloride (1 mole equiv.) in methanol (100 mL). The mixture was stirred at 60° C. for 20 hours, after which it was cooled to room temperature and washed successively with water (three times using 400 mL each time) and isopropanol (one time using 400 mL). Vacuum drying afforded 6.93 g of alkylated product.
[0097] Alkylated products were prepared in an analogous manner using 50%, 200%, and 300% mole equiv of 90% glycidylpropyltrimethylammonium chloride.
[0098] 22. Alkylation of Poly(allylamine) Crosslinked with epichlorohydrin with (10-bromodecyl)trimethylammonium bromide alkylating Agent
[0099] The first step is the preparation of (10-bromodecyl) trimethylammonium bromide as follows.
[0100] 1,10-dibromodecane (200 g) was dissolved in methanol (3 L) in a 5 liter three neck round bottom flask fitted with a cold condenser (−5° C.). To this mixture was added aqueous trimethylamine (176 mL of a 24% aqueous solution, w/w). The mixture was stirred at room temperature for 4 hours, after which is was heated to reflux for an additional 18 hours. At the conclusion of the heating period, the flask was cooled to 50° C. and the solvent removed under vacuum to leave a solid mass. Acetone (300 mL) was added and the mixture stirred at 40° C. for 1 hour. The solid was filtered off, resuspended in an additional portion of acetone (1 L), and stirred for 90 minutes.
[0101] At the conclusion of the stirring period, the solid was filtered and discarded, and the acetone fractions were combined and evaporated to dryness under vacuum. Hexanes (about 1.5 L) were added and the mixture then stirred for 1 hour, after which the solid was filtered off and then rinsed on the filtration funnel with fresh hexanes. The resulting solid was then dissolved in isopropanol (75 mL) at 40° C. Ethyl acetate (1500 mL) was added and the temperature raised to about 50° C. to fully dissolve all solid material. The flask was then wrapped in towels and placed in a freezer for 24 hours, resulting in the formation of solid crystals. The crystals were filtered off, rinsed in cold ethyl acetate, and dried in a vacuum oven at 75° C. to yield 100.9 g of (10-bromodecyl) trimethyl-ammonium bromide as white crystals.
[0102] Poly(allylamine) crosslinked with epichlorohydrin prepared as described in Example 4 (10 g) was suspended in methanol (300 mL). Sodium hydroxide (3.3 g) was added and the mixture stirred until it dissolved. (10-bromodecyl) trimethylammonium bromide (20.7 g) was added and the mixture was refluxed with stirring for 20 hours. The mixture was then cooled to room temperature and washed successively with methanol (two times using 1 L each time), sodium chloride) two times using 1 L of 1 M solution each time), water (three times using 1 L each time), and isopropanol (one time using 1 L). Vacuum drying yielded 14.3 g of alkylated product.
[0103] 23. Alkylation of Poly(allylamine) Crosslinked with epichlorohydrin with (10-bromodecyl)trimethylammonium bromide and 1,10-dibromodecane alkylating Agents
[0104] 1,10-dibromodecane (200 g) was dissolved in methanol (3 L) in a 5 liter round bottom flask fitted with a cold condenser (−5° C.). To this mixture was added aqueous trimethylamine (220 mL of a 24% aqueous solution, w/w). The mixture was stirred at room temperature for 4 hours, after which it was heated to reflux for an additional 24 hours. The flask was then cooled to room temperature and found to contain 3350 mL of clear liquid.
[0105] Poly(allylamine) crosslinked with epichlorohydrin prepared as described in Example 4 (30 g) was suspended in the clear liquid (2 L) and stirred for 10 minutes. Sodium hydroxide (20 g) was then added and the mixture stirred until it had dissolved. Next, the mixture was refluxed with stirring for 24 hours, cooled to room temperature, and the solid filtered off. The solid was then washed successively with methanol (one time using 10 L), sodium chloride (two times using 10 L of a 1 M solution each time), water (three times using 10 L each time), and isopropanol (one time using 5 L). Vacuum drying afforded 35.3 g of dialkylated product.
[0106] 24. Alkylation of Poly(allylamine) Crosslinked with epichlorohydrin with (10-bromodecyl)trimethylammonium bromide and 1-bromodecane alkylating Agents
[0107] Poly(allylamine) crosslinked with epichlorohydrin prepared as described in Example 4 (10 g) was suspended in methanol (300 mL). Sodium hydroxide (4.99 g) was added and the mixture stirred until it dissolved. (10-bromodecyl) trimethylammonium bromide prepared as described in Example 22 (20.7 g) and 1-bromodecane were added and the mixture was refluxed with stirring for 20 hours. The mixture was then cooled to room temperature and washed successively with methanol (two times using 1 L each time), sodium chloride (two times using 1 L of a 1 M solution each time), water (three times using 1 L each time), and isopropanol (one time using 1 L). Vacuum drying yielded 10.8 g of dialkylated product.
[0108] Dialkylated products were also prepared in analogous fashion using different amounts of 1-bromodecane as follows: (a) 3.19 g 1-bromodecane and 4.14 g sodium hydroxide to yield 11.8 g of dialkylated product; (b) 38.4 g 1-bromodecane and 6.96 g sodium hydroxide to yield 19.1 g of dialkylated product.
[0109] Dialkylated products were also prepared in analogous fashion using the following combinations of alkylating agents: 1-bromodecane and (4-bromobutyl)trimethylammonium bromide; 1-bromodecane and (6-bromohexyl)trimethylammonium bromide; 1-bromodecane and (8-bromooctyl)trimethylammonium bromide; 1-bromodecane and (2-bromoethyl)trimethylammonium bromide; 1-bromodecane and (3-bromopropyl)trimethylammonium bromide; 1-bromohexane and (6-bromohexyl)trimethylammonium bromide; 1-bromododecane and (12-bromododecyl)trimethyl-ammonium bromide; and 1-bromooctane and (6-bromohexyl) trimethylammonium bromide.
[0110] 25. Alkylation of Poly(allylamine) Crosslinked with epichlorohydrin with 11-bromo-1-undecanol alkylating Agent
[0111] Poly(allylamine) crosslinked with epichlorohydrin prepared as described in Example 4 (5.35 g) was suspended in methanol (100 mL). Sodium hydroxide (1.10 g) was added and the mixture stirred until it dissolved. 11-bromo-1-undecanol (5.0 g) was added and the mixture was refluxed with stirring for 20 hours, after which it was cooled to room temperature and washed successively with methanol (one time using 3 L), sodium chloride (two times using 500 mL of a 1 M solution each time), and water (three times using 1 L each time). Vacuum drying yielded 6.47 g of alkylated product.
[0112] The reaction was also performed using 1.05 g sodium hydroxide and 10 g 11-bromo-1-undecanol to yield 8.86 g of alkylated product.
[0113] 26. Alkylation of Poly(allylamine) Crosslinked with epichlorohydrin with N-(2,3-epoxypropane)butyramide alkylating Agent
[0114] The first step is the preparation of N-allyl butyramide as follows.
[0115] Butyroyl chloride (194.7 g, 1.83 mol) in 1 L of tetrahydrofuran was added to a three neck round bottom flask equipped with a thermometer, stir bar, and dropping funnel. The contents of the flask were then cooled to 15° C. in an ice bath while stirring. Allylamine (208.7 g, 3.65 mol) in 50 mL of tetrahydrofuran was then added slowly through the dropping funnel while maintaining stirring. Throughout the addition, the temperature was maintained at 15° C. After addition was complete, stirring continued for an additional 15 minutes, after which the solid allylamine chloride precipitate was filtered off. The filtrate was concentrated under vacuum to yield 236.4 g of N-allyl butyramide as a colorless viscous liquid.
[0116] N-allyl butyramide (12.7 g, 0.1 mol) was taken into a 1 L round bottom flask equipped with a stir bar and air condenser. Methylene chloride (200 mL) was added to the flask, followed by 3-chloroperoxybenzoic acid (50-60% strength, 200 g) in five portions over the course of 30 minutes and the reaction allowed to proceed. After 16 hours, TLC analysis (using 5% methanol in dichloromethane) showed complete formation of product. The reaction mixture was then cooled and filtered to remove solid benzoic acid precipitate. The filtrate was washed with saturated sodium sulfite solution (two times using 100 mL each time) and then with saturated dosium bicarbonate solution (two times using 100 mL each time). The dichloromethane layer was then dried with anhydrous sodium sulfate and concentrated under vacuum to yield 10.0 g of N-(2,3-epoxypropane) butyramide as a light yellow viscous liquid.
[0117] Poly(allylamine) crosslinked with epichlorohydrin prepared as described in Example 4 (10 g, −80 sieved) and methanol (250 mL) were added to a 1 L round bottom flask, followed by N-(2,3-epoxypropane) butyramide (0.97 g, 0.0067 mol, 5 mol %) and then sodium hydroxide pellets (0.55 g, 0.01375 mol). The mixture was stirred overnight at room temperature. After 16 hours, the reaction mixture was filtered and the solid washed successively with methanol (three times using 300 mL each time), water (two times using 300 mL each time), and isopropanol (three times using 300 mL each time. Vacuum drying at 54° C. overnight yielded 9.0 g of the alkylated product as a light yellow powder.
[0118] Alkylated products based upon 10 mol %, 20 mol %, and 30 mol % N-(2,3-epoxypropane) butyramide were prepared in analogous fashion except that (a) in the 10 mol % case, 1.93 g (0.013 mol) N-(2,3-epoxypropane) butyramide and 1.1 g (0.0275 mol) sodium hydroxide pellets were used to yield 8.3 g of alkylated product, (b) in the 20 mol % case, 3.86 g (0.026 mol) N-(2,3-epoxypropane) butyramide and 2.1 g (0.053 mol) sodium hydroxide pellets were used to yield 8.2 g of alkylated product, and (c) in the 30 mol % case, 5.72 g (0.04 mol) N-(2,3-epoxypropane) butyramide and 2.1 g (0.053 mol) sodium hydroxide pellets were used to yield 8.32 g of alkylated product.
[0119] 27. Alkylation of Poly(allylamine) Crosslinked with epichlorohydrin with N-(2,3-epoxypropane) hexanamide alkylating Agent
[0120] The first step is the preparation of N-allyl hexanamide as follows.
[0121] Hexanoyl chloride (33 g, 0.25 mol) in 250 mL of tetrahydrofuran was added to a three neck round bottom flask equipped with a thermometer, stir bar, and dropping funnel. The contents of the flask were then cooled to 15° C. in an ice bath while stirring. Allylamine (28.6 g, 0.5 mol) in 200 mL of tetrahydrofuran was then added slowly through the dropping funnel while maintaining stirring. Throughout the addition, the temperature was maintained at 15° C. After addition was complete, stirring continued for an additional 15 minutes, after which the solid allylamine chloride precipitate was filtered off. The filtration was concentrated under vacuum to yield 37 g of N-allyl hexanamide as a colorless viscous liquid.
[0122] N-allyl hexanamide (16 g, 0.1 mol) was taken into a 1 L round bottom flask equipped with a stir bar and air condenser. Methylene chloride (200 mL) was added to the flask, followed by 3-chloroperoxybenzoic acid (50-60% strength, 200 g) in five portions over the course of 30 minutes and the reaction allowed to proceed. After 16 hours, TLC analysis (using 5% methanol in dichloromethane) showed complete formation of product. The reaction mixture was then cooled and filtered to remove solid enzoic acid precipitate. The filtrate was washed with saturated sodium sulfite solution (two times using 100 mL each time) and then with saturated sodium bicarbonate solution (two times using 100 mL each time). The dichloromethane layer was then dried with anhydrous sodium sulfate and concentrated under vacuum to yield 14.2 g of N-(2,3-epoxypropane) hexanamide as a light yellow viscous liquid.
[0123] Poly(allylamine) crosslinked with epichlorohydrin prepared as described in Example 4 (10 g, −80 sieved) and methanol (250 mL) were added to a 1 L round bottom flask, followed by N-(2,3-epoxypropane) hexanamide (4.46 g, 0.026 mol, 20 mol %) and then sodium hydroxide pellets (2.1 g, 0.053 mol). The mixture was stirred overnight at room temperature. After 16 hours, the reaction mixture was filtered and the solid washed successively with methanol (three times using 300 mL each time), water (two times using 300 mL each time), and isopropanol (three times using 300 mL each time. Vacuum drying at 54° C. overnight yielded 9.59 g of the alkylated product as a light yellow powder.
[0124] An alkylated product based upon 30 mol % N-(2,3-epoxypropane) hexanamide was prepared in analogous fashion except that 6.84 g (0.04 mol) N-(2,3-epoxypropane) hexanamide was used to yield 9.83 g of alkylated product.
[0125] 28. Alkylation of Poly(allylamine) Crosslinked with epichlorohydrin with (6-Bromohexyl)trimethylammonium bromide and 1-bromodecane alkylating Agent
[0126] To a 12-1 round bottom flask equipped with a mechanical stirrer, a thermometer, and a condenser is added methanol (5 L) and sodium hydroxide (133.7 g). The mixture is stirred until the solid has dissolved and crosslinked poly(allylamine) (297 g; ground to −80 mesh size) is added along with additional methanol (3 L). (6-Bromohexyl) trimethylammonium bromide (522.1 g) and 1-bromodecane (311.7 g) are added and the mixture heated to 65° C. with stirring. After 18 hours at 65° C. the mixture is allowed to cool to room temperature. The solid is filtered off and rinsed by suspending, stirring for 30 minutes, and filtering off the solid from: methanol, 12 L; methanol, 12L; 2 M aqueous NaCl, 22 L; 2 M aqueous NaCl, 22 L; deionized water, 22 L; deionized water, 22 L; deionized water, 22 L and isopropanol, 22 L. The solid is dried in a vacuum oven at 50° C. to yield 505.1 g of off-white solid. the solid is then ground to pass through an 80 mesh sieve.
[0127] Testing of Polymers
[0128] Preparation of Artificial Intestinal Fluid
[0129] Sodium carbonate (1.27 g) and sodium chloride (1.87 g) were dissolved in 400 mL of distilled water. To this solution was added either glycocholic acid (1.95 g, 4.0 mmol) or glycochenodeoxycholic acid (1.89 g, 4.0 mmol) to make a 10 mM solution. The pH of the solution was adjusted to 6.8 with acetic acid. These solutions were used for the testing of the various polymers.
[0130] Polymers were tested as follows.
[0131] To a 14 mL centrifuge tube was added 10 mg of polymer and 10 mL of a bile salt solution in concentrations ranging from 0.1-10 mM prepared from 10 mM stock solution (prepared as previously described) and buffer without bile salt, in the appropriate amount. The mixture was stirred in a water bath maintained at 37° C. for three hours. The mixture was then filtered. The filtrate was analyzed for total 3-hydroxy steroid content by an enzymatic assay using 3a-hydroxy steroid dehydrogenase, as described below.
[0132] Enzymatic Assay for Total Bile Salt Content
[0133] Four stock solutions were prepared.
[0134] Solution 1—Tris-HCl buffer, containing 0.133 M Tris, 0.666 mM EDTA at pH 9.5.
[0135] Solution 2—Hydrazine hydrate solution, containing 1 M hydrazine hydrate at pH 9.5.
[0136] Solution 3—NAD solution, containing 7 mM NAD+ at pH 7.0.
[0137] Solution 4—HSD solution, containing 2 units/mL in Tris-HCl buffer (0.03 M Tris, 1 mM EDTA) at pH 7.2.
[0138] To a 3 mL cuvette was added 1.5 mL of Solution 1, 1.0 mL of Solution 2, 0.3 mL of solution 3, 0.1 mL of Solution 4 and 0.1 mL of supernatant/filtrate from a polymer test as described above. The solution was placed in a UV-VIS spectrophotometer and the absorbance (O.D.) of NADH at 350 nm was measured. The bile salt concentration was determined from a calibration curve prepared from dilutions of the artificial intestinal fluid prepared as described above.
[0139] All of the polymers previously described were tested in the above manner and all were efficacious in removing bile salts from the artificial intestinal fluid.
[0140] Use
[0141] The polymers according to the invention may be administered orally to a patient in a dosage of about 1 mg/kg/day to about 10 g/kg/day; the particular dosage will depend on the individual patient (e.g., the patient's weight and the extent of bile salt removal required). The polymer may be administrated either in hydrated or dehydrated form, and may be flavored or added to a food or drink, if desired to enhance patient acceptability. Additional ingredients such as other bile acid sequestrants, drugs for treating hypercholesterolemia, atherosclerosis or other related indications, or inert ingredients, such as artificial coloring agents may be added as well.
[0142] Examples of suitable forms for administration include pills, tablets, capsules, and powders (e.g., for sprinkling on food). The pill, tablet, capsule, or powder can be coated with a substance capable of protecting the composition from the gastric acid in the patient's stomach for a period of time sufficient to allow the composition to pass undisintegrated into the patient's small intestine. The polymer may be administered alone or in combination with a pharmaceutically acceptable carrier substance, e.g., magnesium carbonate, lactose, or a phospholipid with which the polymer can form a micelle.
[0143] While this invention has been particularly shown and described with references to preferred embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims. | The invention relates to a method for removing bile salts from a patient in need thereof and compositions useful in the method. The method comprises administering to the patient a therapeutically effective amount of a salt of an alkylated and crosslinked polymer. The alkylated and crosslinked polymer salt comprises the reaction product of crosslinked polymers, or salts and copolymers thereof having amine containing repeat units, with at least one aliphatic alkylating agent. | 2 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a circuit for distributing an ignition signal on every cylinder individually of a multicylinder engine principally for automobile.
2. Description of the Prior Art
FIG. 1 shows a configuration of a conventional ignition signal distributing circuit for a multicylinder engine.
FIG. 1, numeral 1 designates an RS flip-flop having a reset input terminal R of negative logic. An output signal S G of a cylinder identifying sensor 50 of an engine (not shown) is inputted to an input terminal S of this RS flip-flop 1, and an output signal S CR of a crank angle sensor 51 is inputted to a reset input terminal R thereof, respectively.
The cylinder identifying sensor 50 identifies that a first cylinder and a fourth cylinder of the engine are to be ignited, and at this time, outputs a cylinder identification signal by turning the output signal S G to the logic level "1".
Also, the crank angle sensor 51 outputs a crank angle signal by turning the output signal S CR to "1" when each cylinder of the engine is positioned in a predetermined crank angle section.
In FIG. 1, numeral 2 designates an ignition signal arithmetic unit, which inputs the output signal S G of the cylinder identifying sensor 50 and the output signal S CR of the crank angle sensor 51, and operates and outputs signals for ignition signal Sc and Sd on the basis of information on the both signals.
Numeral 3 designates a two-input NAND gate, which inputs the output signal S CR of the crank angle sensor 51 and an output signal Sa from an inversion output terminal Q of the RS flip-flop 1, and outputs a signal Sb.
Numerals 4 and 5 designate two-input NOR gates, and numerals 6 and 7 designate AND gates of one-inversion-input type, and to one input terminal of each gate, a cranking switch signal S SW is inputted. Also, an output signal Sc of the ignition signal arithmetic unit 2 is inputted to the other input terminal of the NOR gate 4, and an output signal Sd of the ignition signal arithmetic unit 2 is inputted to the other input terminal of the NOR gate 5, respectively. The output signal Sa of the RS flip-flop 1 is inputted to the inversion input terminal of the one-inversion-input type AND gate 6, and the output signal Sb of the NAND gate 3 is inputted to the inversion input terminal of the one-inversion-input type AND gate 7, respectively.
Numeral 8 designates a two-input OR gate, whereto each output signal of the NOR gate 4 and the AND gate 6 is inputted. This OR gate 8 distributes a first ignition signal S IG1 to the first cylinder #1 and the fourth cylinder #4 of the engine.
Also, numeral 9 designates a two-input OR gate, whereto each input signal of the NOR gate 5 and the AND gate 7 is inputted. This OR gate 9 distributes a second ignition signal S IG2 to the second cylinder #2 and the third cylinder #3 of the engine.
FIG. 2 is a table showing the state of the inversion output terminal Q responding to the both inputs of the RS flip-flop 1, that is, the state of the output signal Sa. Note that a mark "*" in the Q column shows that the state is the same as the previous state.
FIG. 3 is a waveform diagram showing a signal waveform at each position of the conventional ignition signal distributing circuit for engine shown in FIG. 1.
When power is turned on at a time t1, a cranking switch (not shown) for supplying power to a starter (not shown) is operated from OFF to ON at a time t2, and the cranking switch signal S SW is turned to "1". When the output signal S CR of the crank angle sensor 51 is kept intact at the level "0" at this time, thereafter the first and the second ignition signals S IG1 and S IG2 are outputted alternately at a predetermined timing from the OR gates 8 and 9.
Hereinafter, detailed description is made thereon.
In the case where the output signal S G of the cylinder identifying sensor 50 and the output signal S CR of the crank angle sensor 51 are both "0", the Q output signal Sa of the RS flip-flop 1 whereto the both signals are inputted is turned to "1". Thereafter, the signal Sa is not changed even when the output signal S CR of the crank angle sensor 51 is turned to "1".
In th case where the cranking switch signal S SW is "1", the NOR gates 4 and 5 are disabled, and the one-inversion-input type AND gates 6 and 7 are enabled. Also, the output signal Sb of the NAND gate 3 is turned to "0" only when both of the Q output signal Sa of the RS flip-flop 1 and the output signal S CR of the crank angle sensor 51 are "1". Accordingly, the output signal of the one-inversion-input type AND gate 7 turning the signal Sb from "0" to "1" is turned to "1", and the second ignition signal S IG2 is outputted from the OR gate 9.
Also, in the case where the cranking switch signal S SW is "0", the NOR gates 4 and 5 are enabled, and the one-inversion-input type AND gates 6 and 7 are disabled. Accordingly, when the signal Sd is "0", the output of the NOR gate 5 is turned to "1", and the second ignition signal S IG2 is outputted from the OR gate 9.
The signal Sd has nearly the same phase and the same waveform as those of the signal Sb.
Also, the Q output signal Sa of the RS flip-flop 1 is turned to "1" when both of the signals S G and S CR to the RS flip-flop 1 are "0", and thereafter it is turned to "0" when the output signal S G of the cylinder identifying sensor 50 and the output signal S CR of the crank angle sensor 51 are both turned to "1", and is turned again to "1" when the output signal S CR of the crank angle sensor 51 is turned to "0".
In the case where the cranking switch signal S SW is " 1", when the output signal Sa of the RS flip-flop 1 is "0", the output of the one-inversion-input type AND gate 6 is turned to "1", and the first ignition signal S IG1 is outputted from the OR gate 8.
Also, in the case where the cranking switch signal S SW is "0", if the signal Sc is "0", the output signal of the NOR gate 4 is turned to "1", and the first ignition signal S IG1 is outputted from the OR gate 8.
The signal Sc has nearly the same phase and the same waveform as those of the signal Sa.
The conventional ignition signal distributing circuit for engine is constituted as described above, and therefore, for example, as shown in FIG. 4, power is turned on at a timer t3, and thereafter the cranking switch signal S SW is turned to ON ("1") at a time t5 before a time t6, and the output signal S CR of the crank angle sensor 51 is turned to "1" between the time t3 and the time t6. Between the time t3 and the time t6, "0" is inputted to the set input terminals of the RS flip-flop 1, and "1" is inputted to the inversion reset input terminal R thereof. In this case, the Q output signal Sa of the RS flip-flop 1 becomes *, and can take either value, "0" or "1". Assuming that it is turned to "0", since the output signal of the one-inversion-input type AND gate 6 depends on the cranking switch signal S SW , it is turned to "1" between the time t5 and the time t6. Consequently, the first ignition signal S IG1 of "1" is outputted from the OR gate 8, and thereafter at the time t6, the both input signals S G and S CR of the RS flip-flop 1 are turned to "0", and therefore the Q output signal Sa is turned to "1", and the output of the one-inversion-input type AND gate 6 is turned to "0", and therefore the output of the OR gate 8 is turned to "0". For this reason, a problem is raised that the first ignition signal S IG1 is generated during a duration of time between t5 and t6 when normally operating, the first ignition signal S IG1 must not be generated.
SUMMARY OF THE INVENTION
The present invention has been achieved in the light of such circumstances, and a principal object thereof is to provide an ignition signal distributing circuit for engine capable of avoiding an occurrence of an error ignition signal of an engine.
An ignition signal distribution circuit for a multicylinder engine in accordance with the present invention comprises a cylinder identifying sensor which identifies that predetermined cylinder of the engine is to be ignited and outputs a cylinder identification signal, a crank angle sensor which detects that the crank angle of the engine is a predetermined angle and outputs a crank angle signal, a flip-flop which is inputted output signals of the both sensors, an arithmetic circuit which distributes ignition signals to the engine every cylinder individually on the basis of based on output signals of the both sensors, output signals of the flip-flop and engine starting information, and a delay circuit which delays the output signal of the crank angle sensor or the starting information for the duration from the starting of power supplying to the to completion of the above-mentioned first output signal of the crank angle sensor. In accordance with such a configuration, in the case where the crank angle signal is generated at the starting of power supplying, the signal is delayed by the delay circuit, so that no error signal is generated at all.
The above and further objects and features of the invention will more fully be apparent from the following detailed description with accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a circuit diagram showing a configuration of a conventional ignition signal distributing circuit for engine.
FIG. 2 is a truth table of a flip-flop thereof.
FIG. 3 and FIG. 4 are waveform graphs of signals of a conventional apparatus.
FIG. 5 is a circuit diagram showing a first embodiment of a configuration of an ignition signal distributing circuit for engine in accordance with the present invention.
FIG. 6 and FIG. 7 are waveform graphs of signals thereof.
FIG. 8 is a circuit diagram of a second embodiment of the configuration of the ignition signal distributing circuit for engine in accordance with the present invention.
FIG. 9 and FIG. 10 are waveform graphs of signals thereof.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Hereinafter, detailed description is made on the present invention in reference to drawings showing embodiments thereof.
FIG. 5 shows a first embodiment of a configuration of an ignition signal distributing circuit for a multicylinder engine in accordance with the present invention. In addition, the same reference symbols are given to the portions being same as or corresponding to those of the conventional example as shown in the above-mentioned FIG. 1.
In FIG. 5, numeral 1 designates an RS flip-flop having a negative-logic reset input terminal R.
An output signal S G of a cylinder identifying sensor 50 of a multicylinder engine (not illustrated) is inputted to a set input terminal S of this RS flip-flop 1 and an output signal S CR of a crank angle sensor 51 is inputted to the reset input terminal R through a delay circuit 10 as described later, respectively.
The cylinder identifying sensor 50 identifies that a first cylinder and a fourth cylinder of the engine are to be ignited, and at that time, turns the output signal S G to the logic level "1" to output a cylinder identifying signal.
Also, the crank angle sensor 51 outputs a crank angle signal by turning the output signal S CR thereof to "1" in the case where each cylinder of the engine is positioned in a predetermined crank angle section.
In FIG. 5, numeral 2 designates an ignition signal arithmetic unit, which inputs the output signal S G of the cylinder identifying sensor 50, inputs the output signal S CR of the crank angle sensor 51 through the delay circuit 10, and operates and outputs signals for ignition signals Sc and Sd on the basis of information on the both signals.
Numeral 3 designates a two-input NAND gate, which inputs the output signal S CR of the crank angle sensor 51 and the output signal Sa from an inversion-output terminal Q of the RS flip-flop 1, and outputs a signal Sb.
Numerals 4 and 5 designate two-input NOR gates, and numerals 6 and 7 designate one-inversion input type AND gates, and a cranking switch signal S SW outputted from a cranking switch signal output means is inputted to a one-input terminal of each gate. Also, an output signal Sc of the ignition signal arithmetic unit 2 is inputted to the other input terminal of the NOR gate 4, and an output signal Sd of the ignition signal arithmetic unit 2 is inputted to the other input terminal of the NOR gate 5, respectively. A Q output signal Sa of the RS flip-flop 1 is inputted to an inversion-input terminal of the one-inversion-input type AND gate 6 and an output signal Sb of a NAND gate 3 is inputted to an inversion-input-terminal of the one-inversion-input type AND gate 7, respectively.
Numeral 8 designates a two-input OR gate, whereto each output signal of the NOR gate 4 and the AND gate 6 are inputted. This OR gate 8 distributes a first ignition signal S IG1 to a first cylinder #1 and the fourth cylinder #4 of the engine.
Also, numeral 9 designates a two-input OR gate, whereto each signal of the NOR gate 5 and the AND gate 7 are inputted. This OR gate 9 distributes a second ignition signal S IG2 to the second cylinder #2 and the third cylinder #3 of the engine.
Straightforwardly, in the delay circuit 10, the output signal S CR of the crank angle sensor 51 is outputted to an input terminal 11, and the output signal S CR of the level "1" of the crank angle sensor 51 is removed at the beginning of turn-on of power, and thereafter an output signal Sh1 of the same phase and the same waveform as those of the output signal S CR of the crank angle sensor 51 is outputted to an output terminal 12. This output terminal 12 is connected to the inversion-reset-input terminal R of the RS flip-flop 1, one of input terminals of the ignition signal arithmetic unit 2, and one of input terminals of the NAND gate 3, respectively.
In other words, in the conventional ignition signal distributing circuit for engine, the output signal S CR of the crank angle sensor 51 is inputted directly to the reset-input terminal R of the RS flip-flop 1, one of the input terminals of the ignition signal arithmetic unit 2 and one of the input terminals of the NAND gate 3, but in this embodiment, it is inputted through the delay circuit 10.
In addition, numeral 30 designates a power source for power supplying to this circuit.
Hereinafter, detailed description is made on the delay circuit 10.
Numeral 13a designates a resistor connected between the both terminals 11 and 12.
Also, a diode 14a, a resistor 15 and a capacitor 16 are connected in series between the terminal 12 and the ground level.
Numeral 17 designates a NAND gate, wherein one of input terminals is connected to the input terminal 11 of the delay circuit 10, and the other input terminal is connected to an output terminal Q of an inverter 18 connected to the nongrounded side of the capacitor 16. Also, the output terminal of this NAND gate 17 is connected to a node point of the diode 14a and the resistor 15.
In addition, symbol Se designates an output signal of NAND gate 17, symbol Sf designates the voltage level of the capacitor 16 and symbol Sg designates an output signal of the inverter 18.
Also, the state of the inversion-output terminal Q responding to the both input signals of the RS flip-flop 1, that is, the state of the output signal Sa is similar to the above-described conventional example shown in FIG. 2.
Next, description is made on operation of the ignition signal distributing circuit for engine of the present invention comprising the delay circuit 10 as described above.
FIG. 6 is a waveform graph showing signal waveforms at each position of the ignition signal distributing circuit for an engine of the present invention shown in FIG. 5.
When power is turned on by the power source 30 at a time t1, the output signal S CR of the crank angle sensor 51 is "0". Consequently, an output Se of the NAND gate 17 is turned to "1", and the capacitor 16 starts to be charged through the resistor 15. Thereafter, at a time t10, a voltage level Sr of the capacitor 16 reaches a predetermined level, and the output signal Sg of the inverter 18 is inverted from "1" to "0". The output signal Se of the NAND gate 17 whereto the output signal Sg of the inverter 18 is inputted is kept at the level "1" even when the output signal S CR of the crank angle sensor 51 is turned to "1" at and after the time t10.
Thereby, even if the output signal S CR of the crank angle sensor 51 is turned to "1", it is outputted intact as the signal Sh1 to the output terminal 12 of the delay circuit 10 through the diode 14a without being pulled down.
Accordingly, the output signal S CR of the crank angle sensor 51 and the output signal Sh1 of the delay circuit 10 have the same phase and the same waveform, and therefore the waveform graph is similar to the waveform graph of the conventional example shown in FIG. 3.
Next, in FIG. 7, power is assumed to be turned on by the power source 30 at a time t3. The output signal S CR of the crank angle sensor 51 is kept at "1" from the time t3 to a time t11. Also, the voltage level Sr of the capacitor 16 is "0", and therefore the output signal Sg of the inverter 18 is turned to "1". Accordingly, the output signal Se of the NAND gate 17 is turned to "0", and the capacitor 16 is never charged.
The level "1" of the output signal S CR of the crank angle sensor 51 during a duration of time from t3 to t11 is pulled down through the resistor 13a and the diode 14a, and therefore the output signal Sh1 of the delay circuit 10 is turned to "0".
Thereafter, at the time t11, the output signal S CR of the crank angle sensor 51 is turned to "0". The operation at and after the time t11 is similar to the operation at and after the time t1 in FIG. 6.
Thus, as is understood by comparison with the waveform graph of the above-described conventional example shown in FIG. 3, even if the cranking switch signal S SW has been turned on from a turn-on of power, an error ignition signal is never generated because the output signal Sh1 of the delay circuit 10 is kept at "0" at the beginning.
In addition, the operation at and after the time t11 is similar to the operation at and after the time t3 in FIG. 3, and therefore the first and the second ignition signals S IG1 and S IG2 are outputted alternately at a predetermined proper timing.
FIG. 8 is a view showing a second embodiment of the configuration of the ignition signal distributing circuit for an engine of the present invention.
A difference of this second embodiment from the first embodiment shown in FIG. 1 is the node of a resistor 13b and a diode 14a to an input line of the cranking switch signal S SW in place of the node of the resistor 13b and the diode 14b to an input line of the output signal S CR of the crank angle sensor 51.
A configuration of a delay circuit 20 comprising the input terminal 11, the resistor 13b, the diode 14b, the resistor 15, the capacitor 16, the NAND gate 17 and the inverter 18 is similar to that of the first embodiment.
Operation of the second embodiment having such a configuration is described as follows in reference to waveforms in FIG. 9 and FIG. 10.
Likewise the waveform graph of the first embodiment shown in FIG. 6, in FIG. 8, the output signal Se of the NAND gate 17 is kept at "1" from a turn-on of power, and therefore even if the cranking switch signal S SW is turned to "1" at a time t20 after the time t1, the output signal S CR of the crank angle sensor 51 is not pulled down through the resistor 13b and the diode 14b, and the same is true of the operation at and after the time t20. Accordingly, a signal Sh2 at the time when the cranking switch signal S SW has passed through the resistor 13b is the same as the cranking switch signal S SW , and the same waveform graph as that of the conventional examples shown in FIG. 3 is obtained.
Also, likewise the waveform graph of the first embodiment shown in FIG. 7, in FIG. 10, the output signal Se of the NAND gate 17 is "0" during a duration of time from a turn-on of power t3 to t11, and thereafter it is turned to "1". When the cranking switch signal S SW is turned to "1" at a time t21 between the time t3 and the time t11, it is pulled down through the resistor 13b and the diode 14b, and therefore the signal Sh2 is turned to "0". Thereafter this state is continued intact, and at and after the time t11, the output signal Se of the NAND gate 17 is turned to "1" likewise the case of the first embodiment shown in FIG. 7, and therefore the cranking switch signal S SW of "1" is not pulled down, and the signal Sh2 is turned to "1".
Accordingly, in the early period of time from a turn-on of power t3 to t11, when the output signal S CR of the crank angle sensor 51 is "1", the signal Sh2 becomes "0", and therefore both of the one-inversion-input type AND gates 6 and 7 are disabled, and an error ignition signal is never generated.
As described above, in accordance with the present invention, even when the output signal S CR of the crank angle sensor 51 is generated at the time of a turn-on of power, it is disabled by the delay circuit 10 (20), and therefore the output signal S CR is never outputted from the crank angle sensor 51 in the early period of time. Accordingly, an accurate timing of ignition at engine starting is assured, and even a limited timing of ignition can be reflected reliably.
As this invention may be embodied in several forms without departing from the spirit of essential characteristics thereof, the present embodiment is therefore illustrative and not restrictive, since the scope of the invention is defined by the appended claims rather than by the description preceding them, and all changes that fall within the meets and bounds of the claims, or equivalence of such meets and bounds thereof are therefore intended to be embraced by the claims. | An ignition signal distributing circuit for a multicyclinder engine in accordance with the present invention comprises a delay circuit which delays an output signal of a crank angle sensor or a cranking switch signal for the duration until the first output signal of the crank angle sensor is completed in the early stage of the time immediately after a starting of power supplying, and thereby an output of an error ignition signal can be prevented which is caused by that the crank angle sensor outputs a detection signal when power supplying is started. | 5 |
BACKGROUND
1. Field of Invention
The present invention relates to a machine that bends tubing. The machine employs linear ball bearings to reduce friction in the system.
2. Description of Art
Manufacturers of industrial equipment have been building tube bending machines to bend tubing for decades. One such machine is a vertical compression bending machine. A vertical compression bender makes use of a ram die and two wing dies. During the bending process, the ram die, along with a supporting ram assembly, advances in a linear fashion toward the two wing dies. A tube, supported by the two wing dies, is initially contacted by the ram die during the advancement of the ram assembly. After the ram die makes initial contact with the tube, it continues to push through the tube while forcing the wing dies to rotate away and outward from the ram die. The ram die sees resistance from the tube along with the resistance from the wing dies. In order for the tube to stay up and inside the ram die during the bending process, the wing dies must provide a counter force (cushion) in a direction against the advancing ram die. The counter force from the wing dies will hold the tube in a firm position against the ram die. The ram die continues to advance while at the same time overcoming the resistance of the tube and wing dies. The ram die continues to advance until the tube reaches the required bend angle. At that point, the ram assembly reverses direction and returns to its home position. The wing dies also reverse direction and both wing dies rotate back to their home position.
Over the years manufacturers have relied on various types of wear pads to guide the ram assembly during the bending process. A typical wear pad is constructed from bronze and acts as a bearing surface guiding the ram die and thus the ram assembly during a bending stroke. Wear pads were designed into this application decades ago because they afforded the best load bearing capability at a reasonable cost.
A compression bender is depicted in U.S. Pat. No. 2,997,141 issued to Bower et al. The Bower et al. patent shows a bender that uses guide members 25 and 26 along with wing slides 29 and 30 to ensure that the ram die 36 is guided along a linear path during a bending operation. The guide members 25 and 26 act as wear plates. These wear plates, most often constructed from a bronze material, are the bearing surfaces that allow the ram die to lynamically thrust to and from the wing dies while at the same time providing a bearing surface guide the ram assembly along a linear path.
The Bower et al. patent also uses the same approach when guiding the motion of the piston rods 87 and 96 . Bower et al. relies on the bushings inside the cushion cylinders 77 and 78 to help support the forces on the piston rods 87 and 96 . Cylinders 77 and 78 provide a counter force (cushion) to the advancing ram die 36 . This counter force is transmitted to the ram die 36 through the wing dies 59 and 66 and the tube.
One disadvantage of the Bower et al. patent is the friction associated with the wear plates that guide the ram assembly. These bearing surfaces often require constant maintenance and eventually will need to be replaced due to the friction associated with the wear plates.
Another disadvantage of the Bower et al. patent is the side loads on the piston rods 87 and 96 . These side loads will in time require unnecessary maintenance and thus the bushings in the cylinders 77 and 78 will have to be replaced. In general, these bushings should never take side loading.
SUMMARY OF THE INVENTION
Accordingly, several objects and advantages of my invention are:
(a) to reduce the friction associated with the ram assembly during a bending operation;
(b) to reduce the cost of maintenance associated the ram and cushion assemblies;
(c) to reduce the friction of the bearing assembly used to guide the cushion assembly; and
(d) to prevent a side load from imparting on the cushion cylinder's piston rod.
Still further objects and advantages will become apparent from a consideration of the ensuing description and drawings.
The foregoing objects and advantages can be achieved by providing a vertical compression bending machine comprising a first wind die which supports a second part of the tube, a frame supporting a first linear rail, a first linear bearing which slidably moves along the first linear rail, a ram block mounted to the first linear bearing, and a ram die, mounted to the ram block, which vertically moves to form a bend in the tube, wherein the ram block and first linear bearing move in conjunction with the ram die so that the first linear bearing slides along the first linear rail, and the first and second wing dies provide movable support to the tube as the ram die bends the tube.
DESCRIPTION OF THE DRAWINGS
FIG. 1 shows an isometric view of the first embodiment depicting the linear rail and linear bearing supporting the ram assembly;
FIG. 2 shows an isometric view of the first embodiment depicting a tube being bent;
FIG. 3 shows an isometric view of the wing die assemblies, the cushion assembly, a linear rail supporting the cushion assembly, and a mechanism to adjust the wing dies relative to one another.
FIG. 4 shows an isometric view of the first linear rail and its internal lubrication passage.
FIG. 5 shows an isometric view of the second linear rail and its internal lubrication passage.
FIG. 6 shows the mechanism to adjust the position of the wing dies.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
With initial reference to FIG. 1, the first embodiment 10 is shown. A ram die 11 is mechanically fastened to a ram block 12 . Ram block 12 is mechanically fastened to a linear bearing 13 . Linear bearing 13 may be of the type described by Teramachi in U.S. Pat. No. 4,040,679 and by Teramachi in U.S. Pat. No. 4,252,709.
In both U.S. Pat. No. 4,040,679 and U.S. Pat. No. 4,252,709, Teramachi teaches about a linear bearing that employs recirculating ball bearings. The ball bearings recirculate in a track while the bearing block advances in a linear fashion along a linear rail. The grooves in the linear rail help captivate the ball bearings as the ball bearings recirculate within the bearing block. This technique results in rolling friction as the linear bearing moves relative to the linear rail.
Linear bearing 13 is coupled to a linear rail 14 . A lube passage 63 is formed into linear rail 14 , see FIG. 4 .
Linear rail 14 is fastened to frame 15 . Ram block 12 is fastened to a coupling 17 . Coupling 17 is fastened to a piston rod 18 and piston rod 18 is joined to a ram cylinder 19 . Ram cylinder 19 is fastened to frame 15 .
A wing die 20 is supported by a wear strip 22 , a wear strip 24 , and a wear strip 26 . Wear strips 22 , 24 , and 26 are supported by a support housing 55 . Support housing 55 is fastened to a support block 28 . Support block 28 is fastened to a cushion shaft 30 . Wear strips 22 , 24 , and 26 , support housing 55 , and cushion shaft 30 are considered the first cushion shaft assembly 65 .
A wing die 21 is supported by a wear strip 23 , a wear strip 25 , and a wear strip 27 , see also FIG. 3 . Wear strips 23 , 25 , and 27 are supported by a support housing 56 . Support housing 56 is fastened to a support block 29 . Support block 29 is fastened to a cushion shaft 31 , see also FIG. 3 . Wear strips 23 , 25 , and 27 , support housing 56 , and cushion shaft 31 are considered the second cushion shaft assembly 66 .
Cushion shaft 30 is supported by a bearing block 32 and a bearing block 34 . Bearing blocks 32 and 34 are fastened to frame 15 .
Cushion shaft 31 is supported by a bearing block 33 and a bearing block 35 , see also FIG. 2 . Bearing blocks 33 and 35 are fastened to frame 15 .
From FIG. 2, located in wing dies 20 and 21 is a tube 57 .
From FIG. 1, an encoder bracket 58 is fastened to bearing block 35 . Fastened to encoder bracket 58 is an encoder 59 . Encoder 59 is coupled to cushion shaft 31 .
From FIGS. 3 and 6, a rocker arm 36 and a rocker arm 37 are fastened to cushion shafts 30 and 31 respectively. A rocker bearing 60 is supported by a pin 43 . Pin 43 is fastened to rocker arm 36 . A rocker bearing 61 is supported by a pin 44 . Pin 44 is fastened to rocker arm 37 .
Rocker arm 36 , rocker bearing 38 , and pin 43 are considered the rocker arm assembly 68 . Rocker arm 37 , rocker bearing 39 , and pin 44 are considered the rocker arm assembly 69 .
From FIG. 6, rocker bearings 60 and 61 roll inside a tilt block 40 on surface 40 a and 40 b , respectively. A cap block 41 , fastened to tilt block 40 , captivates rocker bearings 60 and 61 against tilt block 40 , see FIG. 6. A pin 45 supports tilt block 40 . Pin 45 is fastened to housing 42 . A bolt 70 and a bolt 71 are threaded into housing 42 and both bolts 70 and 71 butt up against tilt block 40 . Housing 42 is fastened to a piston rod 49 . Piston rod 49 is connected to a cushion cylinder 50 . Cushion cylinder 50 is fastened to frame 15 . Housing 42 is fastened to a linear bearing 47 . Linear bearing 47 is coupled to a linear rail 48 . Linear rail 48 is fastened to frame 15 .
Linear bearing 47 may be of the type described by Teramachi in U.S. Pat. No. 4,040,679 and by Teramachi in U.S. Pat. No. 4,252,709.
In both U.S. Pat. No. 4,040,679 and U.S. Pat. No. 4,252,709, Teramachi teaches about a linear bearing that employs recirculating ball bearings. The ball bearings recirculate in a track while the bearing block advances in a linear fashion along a linear rail. The grooves in the linear rail help captivate the ball bearings as the ball bearings recirculate within the bearing block. This technique results in rolling friction as the linear bearing moves relative to the linear rail.
Linear bearing 47 is coupled to linear rail 48 . Linear rail 48 is of the type described by Teramachi in U.S. Pat. Nos. 4,040,679 and 4,253,709. A lube passage 64 (see FIG. 5) is formed into linear rail 48 .
Tilt block 40 , cap block 41 , pin 45 , bolt 70 , bolt 71 , and housing 42 make up the cushion assembly 67 .
In operation, pressure is applied to one side of cylinder 19 causing piston rod 18 , initially extended in its home position, to retract toward cylinder 19 . The retraction of piston rod 18 causes coupling 17 , ram block 12 , ram die 11 , and linear bearing 13 to advance toward cylinder 19 .
Prior to ram die 11 making initial contact with tube 57 , sufficient pressure is present in cushion cylinder 50 to cause piston rod 49 to be fully extended in the home position. At this point, wing dies 20 and 21 are adjacent to one another at a right angle as shown in FIG. 1 .
From FIG. 2, the ram die 11 continues to advance toward ram cylinder 19 and thus starts to bend tube 57 . As the bending process continues, a pressure is maintained in cushion cylinder 50 . This pressure creates a counter force (cushion) against the advancing ram die 11 .
The counter force is realized by ram die 11 when wing dies 20 and 21 are forced to rotate about cushion shafts assemblies 65 and 66 . The pressure in cushion cylinder 50 tends to prevent cushion shaft assemblies 65 and 66 from rotating. With a pressure in cushion cylinder 50 , piston rod 49 tends to force cushion assembly 67 away from cushion cylinder 50 . This causes rocker arm assemblies 68 and 69 to keep a counter torque on cushion shaft assemblies 65 and 66 . This counter torque is in opposition to the advancing ram die 11 . As ram die 11 advances, it not only bends tube 57 , but it also forces piston rod 49 to retract into cushion cylinder 50 . Linear bearing 47 and linear rail 48 support cushion assembly 67 and piston rod 49 as piston rod 49 travels in a direction parallel to linear rail 48 . Any side loading caused by rocker arm assemblies 68 and 69 on cushion assembly 67 will be carried by linear bearing 47 and linear rail 48 .
When encoder 59 realizes the preset bend angle, the pressure in ram cylinder 19 causes ram die 11 to return to its home position. This in turn causes cushion cylinder 50 to extend piston rod 49 and thus returns both wing dies 20 and 21 to their home position.
During the initial setup of the machine, it may be necessary to adjust the relative position of wing die 20 with respect to wing die 21 . When in the correct home position, both wing dies 20 and 21 should be adjacent and at a right angle to one another in the home position. Therefore, both die 20 and die 21 should be inline to one another when cylinder 19 is in the extended position. Wing dies 20 and 21 can be adjusted to ensure that both wing dies 20 and 21 are inline to one another (coplanar). By adjusting bolts 70 and 71 , the angle between housing 42 and tilt plate 40 will change. Adjusting bolts 70 and 71 will rotate tilt plate 40 about pin 45 . By advancing bolt 70 and retracting bolt 71 , wing die 20 will rotate up and away from ram cylinder 19 . At the same time, wing die 21 will rotate down and toward ram cylinder 19 . By retracting bolt 70 and advancing bolt 71 toward tilt plate 40 , wing die 20 will rotate down and toward cylinder 19 and wing die 21 will rotate up and away from cylinder 19 . This adjustment feature provides for ease of assembly to ensure that both wing dies are inline (parallel and coplanar) to one another in the home position. When wing die 20 and wing die 21 are inline, the relative angle formed between both dies 20 and 21 is zero. The relative angle is measured in the plane at which tube 57 is being bent.
During operation of the inventive machine, lubrication can be supplied to the rolling elements located inside linear bearings 13 and 47 through lube passage 63 and 64 , respectively. As lubrication is supplied to lube passages 63 and 64 , the rolling elements inside linear bearings 13 and 47 respectively will come in contact with the lubricant being transported through lube passages 63 and 64 .
Linear bearings 13 and 47 make use of ball bearings as a rolling element. It should be noted that the ball bearings could be replaced with roller bearings or needle bearings. Both the roller bearings and needle bearings would take the form of a right circular cylinder. This approach would improve the load bearing capability of the linear bearing.
Cylinders 19 and 50 operate on hydraulic pressure. However, any number of mechanical power devices could replace one or both of cylinders 19 and 50 . For example, an all electric actuator could replace either cylinder 19 and/or cylinder 50 .
Accordingly, the scope of the invention should be determined not by the embodiments illustrated, but by the appended claims and their legal equivalents. | A vertical compression bending machine that uses linear bearings to guide the ram and cushions assemblies. The inventive machine also employs an adjustment mechanism to align the wing dies relative to one another. | 1 |
BACKGROUND OF THE INVENTION
[0001] Areal density improvements have been a main driving force in the progress of magnetic recording technology. Typically, disks (media) in each new disk drive product have a higher signal to noise ratio and the ability to record sharper magnetic transitions than that of previous products. Even a small improvement in signal to noise ratio may significantly impact the recording performance and therefore the areal density of the media.
[0002] Currently, magnetic media evaluation is generally executed by spin-stand tester systems during the media development cycle. The parametric data tested includes overwrite (OW), half-peak pulse width (PW50), track average amplitude (TAA), DC erased signal to noise ratio (DCSNR), spectrum signal to noise ratio (SpSNR), 4TSNR, 2TSNR, 1TSNR, where 1T stands for bit period of written data at high frequency and 4T means ¼ high frequency and SNR stands for signal to noise ratio. This data is generally measured for each disk and then ranked for media design optimization.
[0003] However, it is often the case that media ranked based on these parametric data is not well correlated with hard disk drive (HDD) file data. The most critical parameter in HDD file data is byte error rate (BER). As shown in FIGS. 1A and 1B , the BER of a series disk does not correlate well with media component test parameters, in this case SpSNR. Thus, a bit error rate test is needed to more fully evaluate the media. There are many varieties of BER tests that have been proposed.
[0004] U.S. Pat. No. 6,157,507 describes a performance evaluation method of linking PW50 and SNR to the BER via equation (2) in column 1 and equation (1) in column 4 of the patent. The relationship between BER and SNR is illustrated in FIG. 9 of the patent. For the disk media used in high density (>100 Gb/in2) and high data rate (>500 Mb/s) applications, the performance evaluation method and the described simplified relationship between BER and SNR in this prior art are not as accurate for testing these more modern disk drives. The present invention advantageously uses a more accurate alternate to SNR to determine the BER.
[0005] U.S. Pat. Nos. 5,490,091 and 5,355,261 constructs an algorithm for a partial response maximum likelihood (PRML) data detection channel. This algorithm allows BER to be directly measured. This patent describes PRML chip design and the method for making a PRML integrated circuit (IC) chip for applications in magnetic data storage systems. A PRML chip is a hardware component in a hard disk drive. The present invention is advantageously designed to test a disk drive faster than a device using a PRML chip.
[0006] U.S. Pat. No. 5,121,263 illustrates an algorithm for a PRML data detection channel to directly measure BER. The patent describes a BER evaluation for component-level disk media testing without using an extra hardware.
[0007] The BER tests of the current art have many drawbacks. Current BER tests are usually time consuming since they usually use more than 5 head gimble assemblies (HGA) to test the same disk media surface. The average result of these HGA is defined as the BER for this specific surface. An example is shown in the FIG. 1A , where 5 heads are used, and their average BER value is referred as BER for the disk surface e.g. BER=−7.61 for surface A of disk ID 9312k. The tests are time consuming, taking as much as seven minutes, for a variety of reasons. First, the tests include writing millions of transitions with a variety of bit patterns, and then reading them back while counting the number of error occurrences. Second, it requires a read channel chip optimization to perform the BER tests. The data channel optimization involves complex procedures such as read/writer interface, read interface timing, sector format, servo interface and circuit description, register bit description, detector polynomial control, AE write gate control, servo sequence control, dibit transfer count, read gate timing loop control, and equalization etc.
[0008] Other limitations of current BER tests also exist. For instance, a further limitation of the BER test is that accuracy of BER data is strongly dependent on head stability. This dependency may provide false disk media BER results due to head degradation. In addition head crashes and degradation may adversely affect BER test results. Lastly, BER data is often not correlated well with SNR measurement. Therefore, a new testing method for media performance that is accurate and cost effective is needed.
SUMMARY OF THE INVENTION
[0009] Disclosed is a magnetic test module running on a spinstand tester to measure magnetic parametric data and then construct a functional BER (F-BER) to rank and evaluate magnetic media. The method gathers PW50, signal at low frequency (LF TAA), media noise (N m ), head and electronic noise (N he ), and band width (BW) to determine F-BER. Further the F-BER test uses the ideal simulated E 2 PRML channel, which mimics an optimized real channel with parametric data as input. After data collection, a correlation is established between F-BER and BER. Then F-BER of each disk is employed to rank the disk media.
[0010] The data gathered by the new test takes under one minute to collect. This is a reduction of more than six minutes from the normal BER collection rate of seven minutes. Therefore the under one minute F-BER test allows for higher throughput of media testing procedures and for a potential backlog in the disk test procedure to be reduced. Further, the method allows for more immediate insights into the interplay of different magnetic system parameters before performing time consuming and low through-put BER measurement.
[0011] For a fuller understanding of the nature and advantages of the present invention, reference should be made to the following detailed description taken together with the accompanying figures.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] FIG. 1A is a chart of BER and SpSNR for several disks.
[0013] FIG. 1B is a graph of the correlation between BER and SpSNR for the disks described in FIG. 1A .
[0014] FIG. 2 is a GUI used to implement execution of the F-BER algorithm.
[0015] FIGS. 3A and 3B are a chart and a graph demonstrating results of the F-BER method applied to a disk drive.
[0016] FIGS. 4A and 4B are a chart and a graph demonstrating results of the F-BER method applied to a disk drive.
[0017] FIG. 5 shows an exemplary code module in Visual basic to implement the F-BER algorithm.
[0018] FIG. 6 is a diagram of a spin-stand tester.
DETAILED DESCRIPTION OF THE INVENTION
[0019] A system and method for determining the F-BER and BER of a disk is described herein. The system and method may be implemented with components or modules. The components and modules may include hardware (including electronic and/or computer circuitry), firmware and/or software (collectively referred to herein as “logic”). A component or module can be implemented to capture any of the logic described herein. The F-BER is a method for understanding and determining the BER of a disk by analyzing parametric data of a disk based on an idealized E 2 PRML channel. The F-BER projects the error rate performance of a recording system.
[0020] FIG. 6 is a diagram of a spin-stand tester testing a piece of media. The media 601 is placed on the spin stand tester and is rotated by spindle 603 . The arm and head 604 are attached to a process circuitry controller and read write analyzer (PCCRWA) 606 by wire or wires 605 . The head includes a sensor and a writer that is positioned over a track 602 to test the media. The readings and signals registered by the head are then passed to the PCCRWA to be analyzed.
[0021] During testing, data including read back signals, used to determine F-BER is collected by a module such as PCCRWA. The F-BER data to determine F-BER includes PW50, signal at low frequency (LF TAA), media noise N m , head and electronic noise (N he ), band width. Further the F-BER test uses an ideal E 2 PRML channel, which mimics an optimized real channel with parametric data as input. This data is then provided to a computer to determine the F-BER. Specifically, in addition to typical spin-stand operation, the method calls for adding a head unload operation to obtain head and electronic noise. In this way, one can separate the media noise from total noise by subtracting the head and electronic noise.
[0022] The method for determining the F-BER of a longitudinal disk is as follows and may be performed by a module to determine F-BER. Such a module includes a data processing device that receives F-BER data as described above. The data processing device then determines BW. From BW and the other data, FOM0 and FOM1 may be calculated. The FOM0 and FOM1 calculations are used to determine CSNR. In turn, ψ is determined from CSNR. Finally, the F-BER is determined from ψ. These steps are described in equations (1)-(6).
[0000] FOM 0 =( S 0 /N m ) 2 /(PW50 /T ) (1)
[0000]
FOM
1
=
[
S
0
/
(
N
m
*
BW
)
2
]
a
+
b
*
[
(
PW
50
/
T
)
-
c
]
2
(
2
)
[0000] BW=1/(2 T ) (3)
[0000] CSNR=1/+√{square root over ( d /π/FOM 0 +e /FOM 1 )} (4)
[0000] ω=0.5*CSNR (5)
[0000] FBER=0.5*[1−erf(ψ)] (6)
[0000] where:
N m is the media noise at 2T frequency;
N he is the head & electronic noise (rms noise per root Hz); and
S 0 is LF TAA/2.
[0023] The parameters of a, b, c, d, e in equations (1)-(6) are determined from an E 2 PRML channel. a is preferably 10.8 and ranges from 10 to 12; b is preferably 6.56 and ranges from 6 to 7; c is preferably 1.935 and ranges from 1.75 to 2.25; d is preferably 4.7452 and ranges from 4.5 to 5; e is preferably 0.65685 and ranges from 0.4 to 0.8.
[0024] In addition, two extensions to the algorithm allow F-BER to be calculated for a perpendicular disk. The first extension is measure the T50 of the perpendicular disk on a spinstand. The readback signal from perpendicular media is a square-type waveform. The transition width of a written bit on perpendicular media is called T50, which defines the signal range from 25% to 75% of peak value. From this test, PW50 can be obtained with the use of equation (7).
[0000] PW50=2.77 ×T 50, (7)
[0025] The PW50 value is then incorporated in the F-BER module via the math conversion of equation (7).
[0026] The second possible extension is to add hardware into the spinstand to perform waveform differential. The waveform differentiator allows PW50 of the perpendicular recording to be directly measured.
[0027] The method for determining F-BER can be constructed based on E 2 PRML equalization. Equalization forms generally are described in “Bit Cell Aspect Ratio: An SNR and Detection Perspective”, T. C. Amoldussen, IEEE Trans. Magn. Vol. 34, pp1851-1853 (1998).
[0028] The F-BER method can be a module of a program to perform media testing. Further the F-BER module can be embedded in a spinstand or outside a spinstand. In addition, the module can be made part of a suite or GUI designed to test media as shown in FIG. 2 .
[0029] FIGS. 3A , 3 B, 4 A and 4 B show charts and graphs demonstrating the F-BER method applied to two separate disk drives. As can be seen from the graphs, the F-BER data correlates well with the BER data. Thus F-BER is an effective way of quickly estimating the BER of a media.
[0030] FIG. 5 shows an exemplary code module in Visual basic to implement the F-BER algorithm. The module may be included in any software designed to run a spin stand tester. The module may also be alone or coupled to other modules capable of providing inputs to compute F-BER.
[0031] While the present invention has been particularly shown and described with reference to the preferred embodiments, it will be understood by those skilled in the art that various changes in form and detail may be made without departing from the spirit and scope of the invention. Accordingly, the disclosed invention is to be considered merely as illustrative and limited in scope only as specified in the appended claims. | Spinstand test improvement that measures Functional Byte Error Rate (F-BER) of a disk. The F-BER is correlated to the BER of a disk. The F-BER test is faster than a BER test. The F-BER test is incorporated into a spinstand tester or the software associated with a spinstand tester. | 6 |
FIELD OF THE INVENTION
The present invention relates to a novel fluorine-containing vinyl compound. More particularly, it relates to a fluorine-containing vinyl compound which can modify surface properties of resins or resin compositions, a process for preparing the same and a polymer comprising the same.
BACKGROUND OF THE INVENTION
Compounding of a fluorine-containing compound such as a fluoroalkyl group containing compound as a modifier in resins or resin compositions improves their surface properties such as non-tackiness, leveling property, antistatic property, stainproofness, non-fogging property, water- and/or oil-repellency etc.
Widely used fluorine-containing compounds as the modifier are of single molecular type. Recently, polymers containing polyalkylene oxide group are also used as the modifier. One example of such the polymers is a copolymer of a fluorine-containing monomeric compound having a polyfluoroalkyl group and a polymerizable functional group (eg. a vinyl group) and a monomeric compound having a polyoxyalkylene group and a vinyl group.
The polymers can modify or improve the surface properties as described above to a certain degree by appropriately selecting kinds and proportion of the fluorine-containing compound and the compound copolymerizable therewith. However, the improvement of the surface properties is not practically satisfied.
As a result of the extensive study to find a good modifier of the surface properties of the resins or the resin compositions, it has now been found that a vinyl compound having both a polyfluoroalkyl group and a polyoxyalkylene group improves the surface properties greatly.
SUMMARY OF THE INVENTION
According to one aspect of the invention, there is provided a fluorine-containing vinyl compound of the formula: ##STR2## wherein Rf is fluoroalkyl of 4 to 20 carbon atoms, R 1 is hydrogen or acyl of 1 to 3 carbon atoms, one of R 2 and R 3 is hydrogen and the other is methyl, R 4 is hydrogen or methyl, A is a divalent organic group, and l, m and n are each an integer of 0 to 40 and satisfy 0<l+m+n≦40.
According to another aspect of the invention, there is provided a process for preparing the fluorine-containing compound (I) comprising reacting a fluorine-containing epoxide of the formula: ##STR3## wherein Rf is the same as defined above and a compound of the formula: ##STR4## wherein R 2 , R 3 , R 4 , A, l, m and n are the same as defined above, preferably in the presence of a catalyst, to obtain a compound of the formula: ##STR5## wherein Rf, R 2 , R 3 , R 4 , A, l, m and n are the same as defined above, and optionally esterifying the compound (IV) to obtain a vinyl compound (I) wherein R 1 is acyl of 1 to 3 carbon atoms.
According to further aspect of the invention, there is provided a polymer comprising monomeric units derived from the vinyl compound (I).
DETAILED DESCRIPTION OF THE INVENTION
In the compound (I), Rf usually have 4 to 20 carbon atoms, preferably 6 to 15 carbon atoms, more preferably 8 to 12 carbon atoms.
Specific examples of the divalent organic group A are divalent aliphatic groups aush as --(CH 2 ) p -- in which p is an integer of 1 to 3 carbon atoms (eg. --CH 2 --, --CH 2 CH 2 --, etc), divalent aromatic groups such as a group of the formula: ##STR6## in which X is hydrogen or alkyl having 1 to 4 carbon atoms (eg. phenylene), --CO--, --NHCO--, --SO 2 --, etc.
Specific examples of the vinyl compound (I) are as follows: ##STR7##
Usually, the reaction of the compounds (II) and (III) is carried out at a temperature of from 40° to 100° C., preferably 50° to 80° C. As the catalyst, an acidic catalyst (eg. BF 3 -ether complex, AlCl 3 , ZnCl 2 , Zn(NO 3 ) 2 , etc.) is used and among them, BF 3 -ether complex is preferred. The amount of the catalyst is usually from 0.01 to 2% by weight on the basis of the weight of the fluorine-containing epoxide (II).
After the reaction of the compounds (II) and (III) is completed, the compound (IV) is esterified with a corresponding carboxylic anhydride or carboxylic acid halide (eg. carboxylic acid chloride) according to a per se conventional method. Esterification may be carried out in the absence of a catalyst at a temperature of 10° to 80° C., preferably 30° to 50° C.
The vinyl compound (I) according to the invention is as such used as the modifier of the resin surface.
When the vinyl compound (I) is used in an aqueous system, it has preferably no propylene oxide or more ethylene oxide than propylene oxide in the molecule, because of its better solubility in water. More desirable compound (I) is one in that l+m+n is not less than 2, preferably not less than 4.
When the vinyl compound (I) is used in an organic solvent system, particularly in a non-polar solvent such as petroleum oil, it has no ethylene oxide or more propylene oxide than ethylene oxide in the molecule because of its better solubility to the organic solvent.
When the improvement of the leveling property of the surface is intended, the vinyl compound having both ethylene oxide and propylene oxide (namely m is at least one and at least one of l and n is at least one) provides better effect.
When the improvement of the non-fogging property is intended, advantageously, at least 80% of R 2 and R 3 is hydrogen.
The vinyl compound (I) in which the group A is --CO-- is advantageously used for generally used resins such as acrylic resin, epoxy resin, urethane resin, polyvinyl chloride resin and phenol resin, since it has good compatibility with them. Further, the vinyl compound (I) in which the group A is ##STR8## is advantageously used with non-polar resins such as polyolefins (eg. polyethylene and polypropylene), polystyrene, etc.
As discussed above, the groups in the formula (I) may be appropriately selected in accordance with the objects and/or the kind of the resin to be modified by the vinyl compound (I).
Although the vinyl compound (I) may be used as such as discussed in the above, it may be used in the form of a homopolymer or a copolymer with at least one other comonomer in order to improve its effect and its durability.
The polymerization or copolymerization of the vinyl compound (I) may be carried out by a per se conventional manner such as solution polymerization, emulsion polymerization, bulk polymerization, etc.
The polymerization or copolymerization conditions are easily selected by those skilled in art according to the conventional polymerization of known vinyl compounds.
For example, the reaction temperature is from 40° to 80° C., preferably from 50° to 70° C. In the solution and emulsion polymerization, a solvent such as ethanol, isopropanol, ethyl acetate, trichloroethane, methyl ethyl ketone and dimethylformamide is preferably used. As an emulsifier in the emulsion polymerization, polyethyleneglycol and nonyl phenol ether are preferably used. As an initiator, a conventional radical initiator such as an organic or inorganic peroxide (eg. tert-butyl peroxypivarate, tert-butyl 2-ethylhexanoate, etc.), an azo compound (eg. 2,2'-azobisisobutyronitrile, etc.) may be used. The polymerization or copolymerization may be initiated by light or heat.
Specific examples of the comonomer to be copolymerized with the vinyl compound (I) are unsaturated carboxylic acids (eg. acrylic acid, methacrylic acid, etc.), unsatureted carboxylates (eg. methyl acrylate, 2-ethylhexyl acrylate, polyethylene glycol monoacrylate, polyethylene diacrylate, aminoethyl acrylate, polypropylene monoacrylate, polyethylene polypropylene monoacrylate, methyl methacrylate, hydroxyethyl methacrylate, dimethylaminoethyl methacrylate, polyethylene monomethacrylate, polypropylene monomethacrylate, glycidyl methacrylate, etc.), unsaturated carboxylic acid amides (eg. acryl amide, methylolacryl amide, etc.), styrene, alpha-methylstyrene, divinyl benzene, vinyl alcohol, vinyl ether (eg. methyl vinyl ether, ethyl vinyl ether, etc.), acrylonitrile, methacrylonitrile, vinyl amine, vinyl chloride. Other vinyl monomers may be suitably used.
The modification of the resin surface may be effected by coating the surface with a solution of the vinyl compound (I) or its homo- or copolymer in an appropriate solvent. Specific examples of the solvent are halogenated solvents (eg. trichlorotrifluoroethane, tetrachlorodifluoroethane, tetrachloromethane, trichloroethane, etc.)
Alternatively or in addition to the coating, the vinyl compound (I) or its homo- or copolymer may be compounded in the resin or in the resin composition by adding it in the solution of the resin or kneading it together with the resin or the resin composition in a melt state. The amount of the vinyl compound (I) or its homo- or copolymer to be compounded varies with the kinds of the compound (I) and/or of the resin to be modified. Usually, it is from 0.001 to 2% by weight.
PREFERRED EMBODIMENTS OF THE INVENTION
The present invention will be hereinafter explained further in detail by following Examples.
EXAMPLE 1
In a 200 ml flask equipped with a thermometer, a condenser and a stirrer, ##STR9## (52.6 g, 0.1 mole), HO(CH 2 CH 2 O) 10 COC(CH 3 )═CH 2 (52.6 g, 0.1 mole) and, as a catalyst, BF 3 -ether complex (0.26 g) were charged and stirred at 70° C. for 8 hours. Analysis by gaschromatography (Column: silicone SE-30, 1 m. Column temperature: raised from 100° C. to 250° C.) confirmed the consumption of the starting material epoxide. A peak at 1,640 cm -1 in IR spectrum confirmed the presence of double bonds.
After removing insoluble materials in methanol from the reaction mixture, the resulting product was washed with benzene and dried in vacuo to give, as a transparent viscous liquid, C 9 F 19 CH 2 CH(OH)CH 2 O(CH 2 CH 2 O) 10 COC(CH 3 )═CH 2 (96.8 g). Yield, 92%. M.P., 10°-15° C. B.P., 200° C./10 mmHg.
Elemental analysis: Calculated: F, 34.3%; C, 41.1%; H, 4.8%, O, 19.8%. Found: F, 33.7%; C, 40.8%; H, 4.9%; O, 20.6%.
EXAMPLE 2
In the same flask as used in Example 1, ##STR10## (47.6 g, 0.1 mole), HO(CH 2 CH 2 O) 10 (CH(CH 3 )CH 2 O) 5 COC(CH 3 )═CH 2 (81.6 g, 0.1 mole) and BF 3 -ether complex (0.4 g) were charged and stirred at 65° C. for 9 hours. The consumption of the epoxide and the presence of the double bonds were confirmed in the same manner as in Example 1.
After removing insoluble materials in methanol from the reaction mixture, the resulting product was washed with an excess amount of benzene and dried in vacuo to give as a transparent viscous liquid, C 8 H 17 CH 2 CH(OH)CH 2 O(CH 2 CH 2 O) 10 (CH(CH 3 )CH 2 O) 5 COC(CH 3 )═CH 2 (117.6 g). Yield, 91%. M.P., 8°-12° C. B.P., 200° C./10 mmHg.
Elemental analysis: Calculated: F, 25.0%; C, 46.4%; H, 6.3%, O, 22.3%. Found: F, 24.1%; C, 46.8%; H, 6.3%; O, 22.8%.
EXAMPLE 3
In a 200 ml four-necked flask equipped with a thermometer, a condenser, a stirrer and a nitrogen-inlet tube, the compound obtained in Example 1 (28 g), isopropanol (112 g) and dodecyl mercaptan (0.4 g) were charged and stirred at 67° C. for 30 minutes under a nitrogen stream. Then, as a polymerization initiator, perbutyl pivalate (0.17 g) was added and the polymerization was effected at the same temperature for 6 hours.
Isopropanol was evaporated off. The residue was washed with an excess amount of benzene and dried in vacuo to give a highly viscous liquid (26.1 g). M.P., 25°-30° C. B.P., 200° C./10 mmHg.
An IR spectrum, the peak at 1,640 cm -1 corresponding to the double bond of the starting material was disappeared, which confirmed the formation of the polymer.
EXAMPLE 4
In the same flask as used in Example 1, ##STR11## (52.6 g, 0.1 mole), HO(CH(CH 3 )CH 2 O) 10 COC(CH 3 )═CH 2 (66.6 g, 0.1 mole) and BF 3 -ether complex (0.5 g) were charged and stirred at 65° C. for 8 hours. The consumption of the epoxide and the presence of the double bonds were confirmed in the same manner as in Example 1.
After removing insoluble materials in methanol from the reaction mixture, the resulting product was washed with an excess amount of hexane and dried in vacuo to give as a transparent viscous liquid, C 9 F 19 CH 2 CH(OH)CH 2 O(CH(CH 3 )CH 2 O) 10 COC(CH 3 )═CH 2 (102.5 g). Yield, 86%. M.P., -1-+2° C. B.P., 200° C./10 mmHg.
Elemental analysis: Calculated: F, 30.2%; C, 46.4%; H, 6.0%, O, 17.4%. Found: F, 29.7%; C, 46.7%; H, 6.1%; O, 17.5%.
EXAMPLE 5
A resin coating composition having following formulation and containing 0.04% by weight of a polymer as shown in Table 1 was spray coated on an aluminum plate (10 cm×10 cm) and dried at 140° C.
______________________________________Formulation % by weight______________________________________Epoxy resin 20Phenol resin 10Butanol 15Xylene 40Cellosolve acetate 12Titanium oxide 3______________________________________
Smoothness of the surface of the coating was examined by naked eyes with reflected natural light and by mirror reflection rate at 60 degrees and evaluated according to the following criteria:
O: good smoothness over the entire surface
Δ: Fairly good smoothness
X: Poor smoothness
The results are shown in Table 1.
TABLE 1__________________________________________________________________________Polymer Smoothness__________________________________________________________________________None XHomopolymer of Δ ##STR12##Homopolymer of O ##STR13## Copolymer of O ##STR14##and ##STR15##__________________________________________________________________________
EXAMPLE 6
A base film of acetate resin was dipped in a 0.01% by weight solution of a polymer shown in Table 2 in trichlorotrifluoroethane and dried in the air to form a polymer film on the base film. Frictionally charged voltage on the film was measured by means of a Kyoto University-type rotary static tester using polytetrafluoroethylene as a frictional belt. The results are shown in Table 2.
TABLE 2______________________________________ Frictionally charged voltagePolymer (Volts)______________________________________None 2,000Homopolymer of 120 ##STR16##Homopolymer of 150 ##STR17##______________________________________
EXAMPLE 7
A resin composition was prepared by compounding polyvinyl chloride (100 parts by weight), dioctyl phthalate (44 parts by weight) and, as a anti-drip agent, a sorbitan monostearate/ethylene oxide adduct (one part by weight) and sorbitan monoparmitate (one part by weight) and adding a compound (0.2 part by weight) shown in Table 3 as an anifogging agent. The composition was calender rolled to form a film having a thickness of 0.1 mm. A dome having a diameter of 50 cm and a height of 30 cm was constructed of the thus prepared film, and in the dome, a glass container (20 cm×20 cm×5 cm) filled with water was placed. Room temperature was varied between 5° C. and 30° C. and a degree of fog creation was evaluated according to the following criteria:
O: Fog was not created.
Δ: Fog was slightly created.
X: Fog was densely created.
The results are shown in Table 3.
TABLE 3______________________________________Compound Evaluation______________________________________None X ##STR18## OHomopolymer of Δ ##STR19##Copolymer of O ##STR20##and ##STR21##______________________________________ | A fluorine-containing vinyl compound of the formula: ##STR1## wherein Rf is fluoroalkyl of 4 to 20 carbon atoms, R 1 is hydrogen or acyl of 1 to 3 carbon atoms, one of R 2 and R 3 is hydrogen and the other is methyl, R 4 is hydrogen or methyl, A is a divalent organic group, and l, m and n are each an integer of 0 to 40 and satisfy 0<l+m+n≦40, which can modify surface properties of resins. | 2 |
BACKGROUND
1. Technical Field
The present invention relates to motion capture devices cooperating with a host device in order to record captured motion, particularly, but not limited to, mice intended to communicate with a computer.
2. Description of the Related Art
FIG. 1 shows an example of a known motion capture and display system. A device 1 , for example an optical mouse, comprises measuring means 2 , 3 comprising for example a lens and a sensor represented by 2 . The sensor captures images, which it sends to displacement determination means 3 . These means 3 compare the images received to determine a displacement between successive images.
Such displacement is commonly measured in two dimensions. In the present description, the terms “displacement”, “points”, “counts”, “displacement measurement”, “number of pixels”, etc. are commonly understood to mean pairs of values, for example (X, Y). Of course, the concepts of “displacement”, “points”, etc. may also correspond to triplets of values for measurements in three dimensions, or single values for measurements in one dimension.
Each displacement is counted in “counts”, with each count corresponding to a 32nd of a point.
For example, if the sensor associates a point with a distance of 30 μm, and the lens has a gain of 2, then the determination means 3 associate a point with an actual displacement of 60 μm.
A displacement of 25.4 mm (one inch) in a given direction therefore corresponds to the integer value of
25.4 2 * 30 * 10 - 3 * 32 ,
which is 13546 counts.
Weighting means 9 weight the number of counts by a gain motion_scaling. A shift in the corresponding register divides the result by 256. Thus for a motion_scaling of 8, a CPI (counts per inch) parameter equals the integer of
13546 * 8 256 ,
that is 423 counts per inch.
The means 3 , 9 , may be integrated into the same means for processing, for example a processor 10 .
For each displacement, and for each direction x,y, the weighted counts are sent to an accumulator 4 which adds the number of counts sent to an accumulated number of counts.
The values X, Y stored in the accumulator 4 are regularly read, truncated, then sent to a buffer of a processor 5 of a host device, for example a central processing unit 8 , using for example a USB bus. In the case of a wireless mouse, a wireless communication protocol may be provided for transmitting each number of accumulated counts to the processor of the central processing unit.
After each read, the truncated, meaning rounded, value is deducted from the value stored in the accumulator 4 . In this manner the accumulator 4 continues to receive the values of the weighted number of counts between two reads.
A driver program run by the processor 5 may be used to amplify by a given factor each value for the number of accumulated counts received. The driver also allows displacing a pointer 6 on a screen 7 by a number of pixels approximately proportional to each amplified value and in the corresponding direction. The motions of the pointer 6 on the screen are thus approximately proportional to the motion captured by the capturing means 2 .
For a factor equal to 1, each count transmitted is represented by an apparent displacement of one pixel on the screen. The factor may be greater than or less than 1.
With the improved resolution of monitors, the number of pixels per screen is tending to increase. In order to avoid a decrease in the apparent displacement of the pointer on the screen for a given mouse displacement, the number of pixels for a given actual displacement is also tending to increase.
To increase the number of pixels corresponding to a given displacement, one may increase the factor applied by the driver in the host device and/or the CPI parameter applied in the mouse 1 .
Currently there is no existing standard which imposes the value of the total gain (or CPI parameter) applied by the mouse. The motion_scaling gain may even be programmable, such that the value of the CPI parameter may be chosen relatively freely by the mouse manufacturer.
In this manner, the usual value of the CPI parameter for mice has grown from around 400 CPI to around 800 CPI within only a few years. One may imagine mice with a CPI parameter of around 1600 or even 3200 CPI for high resolution monitors or certain video games.
However, the value of the accumulated number of counts stored in the accumulator may then grow relatively quickly.
The channel used to transmit the value stored in the accumulator to the host device has limited bandwidth. Reading the value stored in the accumulator is therefore done at a predetermined maximum report rate.
For example, for a USB port, the HID (Human Interface Device) specification authorizes reading 8 bytes every 8 milliseconds. Of these 8 bytes, four are dedicated to the transmission of information about the mouse button clicks (not represented). The four remaining bytes are dedicated to the transmission of the values stored in the accumulator. Therefore for each direction x, y, two 8-bit bytes may be transmitted every 8 milliseconds.
A PS2 port is limited to 4 bytes every 8 milliseconds.
If transmitting using 27 MHz wireless technology, the bandwidth may be close to that of the HID specification, including the encoding which must occur for error protection. For example, for a wireless mouse capable of transmitting 8 signed bits of data every 10 milliseconds for each direction x, y, 127 counts (positive or negative) may be transmitted every 10 milliseconds, which is 12700 counts per second. If the value of the CPI parameter is 400 CPI, this limitation corresponds to a maximum mouse speed in direction x or y of
12700 400 * 25.4 * 10 - 3
meters per second, which is approximately 0.8 m/s. If the value of the CPI parameter is 1600 CPI, the maximum speed in direction x or y falls to approximately 0.2 m/s. If the user moves the mouse more quickly, transmission to the host device encounters overflow problems. This limitation may become an annoyance for certain applications, such as gaming applications.
One solution consists of choosing a relatively low CPI parameter and a relatively high factor to be applied by the driver. This factor may be modified relatively easily via a user interface. In this manner, someone using the mouse is not constrained to move the mouse over relatively high distances in order to display a given pointer displacement on the screen. Also avoided are the problems related to overflow when transmitting the accumulated number of counts from the mouse to the host device.
However, the displacements shown on the screen may be imprecise. The number of counts corresponding to a given displacement is relatively low, such that the displacement is translated into a number of counts in an approximate manner only. In addition, if the factor used by the driver is relatively high, the apparent minimum displacement, corresponding to one count, may be greater than a pixel.
It is also known to provide a variable factor to be applied by the driver. If an acceleration is detected, the factor decreases. However, this solution does not eliminate the loss of precision related to the conversion into the number of counts. When no acceleration is detected, the factor may be relatively high, which increases the loss in precision. In addition, detection of acceleration by the software of the computer may lead to artifacts on the screen. One example would be relatively abrupt changes in the pointer direction.
BRIEF SUMMARY
One embodiment remedies the disadvantages mentioned above. It proposes providing a CPI parameter that varies with the speed of the capture device.
One embodiment is a motion capture device designed to communicate with a host device in order to input data on the captured motion, comprising weighting means for weighting the displacement measurements with a gain, and adjusting means to adjust the gain as a function of at least one speed of the capture device.
In this manner one may decrease the gain when the capture device, for example a mouse, captures a relatively rapid motion. This avoids the problems related to overflow during transmission to the host device.
When the capture device captures a relatively slow motion, the gain may be relatively high. The captured motion, represented for example by the apparent displacement of a pointer on a screen of the host device, is thus relatively high. For a screen comprising a relatively high number of pixels, this avoids a decrease in the apparent displacement of the pointer on the screen for a given displacement of the mouse. In addition, the precision remains relatively high. The loss of precision due to a quantification of the motion as a number of counts is relatively low. And the factor applied by the host device may be relatively low, avoiding minimum displacements on the screen that exceed one pixel. In other words, each pixel on the screen may be reached by the pointer.
Advantageously, the adjusting means are arranged to modify the gain as a function of at least one previously acquired displacement measurement.
If the measurements are acquired at regular intervals, the speed of the capture device and the measurement(s) are approximately proportional. Of course, other indicators of the speed may be used to adjust the gain of the capture device.
Advantageously, the adjusting means are arranged to modify the gain as a function of the sum of multiple previously acquired displacement measurements. This corresponds to low-pass filtering (or smoothing), which avoids variations in the gain due to excessive sensitivity.
Alternatively, the gain may be readjusted based on a single displacement measurement.
Advantageously, the capture device comprises an accumulator connected to the weighting means, where the accumulator receives weighted displacement measurements and stores an accumulated displacement measurement. A communication means are provided, comprising a transmission buffer designed to receive an accumulated displacement measurement read from the accumulator. The communication means are designed to communicate to the host device the value received in the transmission buffer.
Conventional mouse capture devices commonly integrate the accumulator and such a means of communication. For example, one may obtain mice according to the first embodiment of the invention relatively easily, for example by modifying a computer program executed by a mouse processor.
Conventionally, the value read from the accumulator and received in the transmission buffer is truncated, and this truncated value is subtracted from the value stored in the accumulator. Because the weighting means are located upstream from the accumulator, a relatively high resolution may be maintained because the weighting is applied to the untruncated values.
The present invention is, of course, not limited by any of these characteristics, meaning the accumulator, the transmission buffer, or the means of communication. For example, the weighted measurements may be communicated one by one to the host device, without prior accumulation in an accumulator.
Advantageously, the adjusting means are connected to the transmission buffer, in order to modify the gain as a function of at least one measurement read from the accumulator. In this manner the gain is readjusted at each transmission to the host device, while multiple displacement measurements are acquired between two transmissions.
Alternatively, the means of adjustment may be without a direct connection to the transmission buffer. One may, for example, have the means of adjustment itself read from the accumulator at regular intervals, independently of the read from the accumulator done for the transmission to the host device.
The invention is not limited by the implementation of the communication with the host device: for example a PS2 port, a USB port, or wireless means of communication (radio link, Bluetooth, infrared, etc.) may be used. In the case of a mouse, it may of course be wired or wireless.
The means of adjustment may take into account the nature of the communication means between the capture device and the host when calculating the value of the gain. Typically, the gain may be adjusted such that the data sent to the host are sufficiently small in size for the transmission to the host to occur without overflow.
In one embodiment, the capture device is an optical mouse in which case the displacements measured are those of the mouse itself relative to a support such as a table or mouse pad, and the speed of the capture device is the speed of the mouse relative to this support. The mouse may also be a 3D mouse.
In another embodiment, the capture device is a mouse that may comprise a trackball, in which case the displacements measured are those of the ball, and the speed of the capture device is the speed of the ball. The mouse may also be a conventional optical mouse, Alternatively, the capture device may be (or may be comprised within) a touchpad device or a trackpoint device, in which case the displacements measured are those of the user's finger across the touchpad or trackpoint. The speed of the capture device is then the speed of the touchpad (or trackpoint) relative to the finger, which is the same as speed of the finger relative to the touchpad (or trackpoint).
Alternatively, the capture device may be (or may be comprised within) a graphics tablet, in which case the displacements measured are those of a tool, for example a stylus, across a surface of the tablet. Here again, the speed of the capture device is equal to the speed of the tool across the surface of the tablet.
Therefore the invention is in no way limited by the nature of the capture device. The capture device may also be (or may be comprised within) a joystick.
One embodiment is a motion capture system comprising the capture device according to the first aspect of the invention and a host device which is able to communicate with the capture device. The capture system may, for example, comprise an optical mouse and a computer's central processing unit.
Another embodiment is a method to be implemented by a motion capture device which communicates with a host device in order to input the captured motion. Said method comprises modifying a gain as a function of at least one speed of the capture device, and using this gain to weight a displacement measurement of the capture device.
Of course, the modifications to the gain and the weighting may be done at different frequencies. For example, the gain may be readjusted after one hundred weightings.
Another embodiment is a computer readable medium having contents that cause a motion capture device to perform a method that includes:
receiving data from a sensor of the capture device, determining a displacement measurement of the capture device from data received from the sensor, weighting said displacement measurement by a gain, and modifying the gain as a function of a speed of the capture device.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
Other features and advantages of the invention will become clear in the description of the embodiments which follows.
FIG. 1 , already described, shows an example of a known capture system from the prior art.
FIG. 2 shows an example of a capture system according to one embodiment of the invention.
FIG. 3 is a flowchart showing an example of a process according to the embodiment in FIG. 2 .
FIG. 4 is a graph representing an example of a variation in the gain as a function of the capture device speed, according to the embodiment in FIG. 2 .
FIGS. 2 , 3 and 4 correspond to the same embodiment and will be described at the same time.
DETAILED DESCRIPTION
The capture system represented in FIG. 2 comprises a capture device and a host device, which in this embodiment are respectively an optical mouse 21 and a central processing unit 28 of a computer.
The mouse 21 comprises an optical sensor and a lens, labeled as number 22 . The sensor captures image data P 1 , P 2 and sends these image data to displacement determination means 23 . The image data P 1 , P 2 typically correspond to images captured at given instants. The determination means receive the image data (step 32 in FIG. 3 ). By comparing the image data P 1 , P 2 captured between two instants, the determination means 23 determines a displacement measurement (Δx,Δy) in two dimensions x, y, corresponding to an interval of time between these two instants (step 33 in FIG. 3 ).
Each displacement measurement (Δx,Δy) is counted as counts, with each count corresponding to a 32nd of a point.
For example, for a sensor associating a point with a distance of 30 μm, and for a lens with a gain of 2, an actual displacement of 25.4 mm (one inch) in direction x or y corresponds to the integer of
25.4 2 * 30 * 10 - 3 * 32 ,
which is 13546 counts.
Weighting means 29 weight the displacement measurements by a gain G (step 34 in FIG. 3 ). The gain G is equal to a gain motion_scaling divided by 256 via shifts in the register where the displacement measurement is temporarily stored (Δx,Δy).
The gain motion_scaling may be modified by the means for adjusting the gain 31 , as a function of the mouse speed.
The means 23 , 29 , 31 may be integrated into the same processing means, for example a processor 30 .
The processor 30 is connected to an accumulator 24 . Each weighted displacement measurement (Δx′,αy′) is sent to the accumulator 24 and added (step 36 in FIG. 3 ) to an accumulated displacement measurement (X, Y) in two dimensions x, y.
The accumulator 24 is designed to allow storing relatively high values for each dimension x, y, of the accumulated displacement measurement (X, Y), in order to avoid problems related to a possible overflow.
For each dimension x, y, the stored values are read and truncated (step 37 in FIG. 3 ), then received in a transmission buffer 42 for transmission to a buffer of a processor 25 of the central processing unit 28 . Communication means including the buffer 42 are provided for this purpose.
In the case of a wireless mouse, a wireless communication protocol may be provided for transmitting the number of counts accumulated in the processor 25 . In addition to the buffer 42 , the communication means may, among other components, comprise a wireless transmitter/receiver 40 .
In the case of a USB bus operating according to the HID specification, not represented in FIG. 2 , communication means may, among other components, comprise a wire between the mouse and the central unit.
After each read, and for each direction, the truncated value is deducted from the value saved in the accumulator 24 (step 38 in FIG. 3 ). Alternatively, the accumulator 24 may be reset to zero.
The accumulator 24 continues to receive weighted values for the number of counts between two reads.
In addition, for each direction x, y, the value received in the buffer 42 is sent to the gain adjusting means 31 . The gain adjusting means 31 in fact determine (step 35 in FIG. 3 ) the value of the gain motion_scaling, and therefore the gain G, from the accumulated displacement measurement (X, Y) read from the accumulator 24 during the read step.
In fact, the accumulated displacement measurement (X, Y) corresponds to the displacement captured between two reads from the accumulator. If the reads from the accumulator take place at regular intervals, the accumulated displacement measurement (X, Y) is representative of the mouse speed. From the values in the directions x, y of the accumulated measurement (X,Y), and from the current value of the gain motion_scaling, the processor 30 may easily determine a value approximately proportional to the mouse speed.
FIG. 4 is a graph representing an example of variations in the motion_scaling as a function of the mouse speed.
In this example, the motion_scaling is expressed as multiples of a value K equal to 8.
While the speed of the mouse is less than 0.19 m/s, the motion_scaling is equal to 32, which is a gain G of 0.125 after considering the shifts in the shift register. An actual displacement of 25.4 millimeters (one inch) in one of the directions x, y thus corresponds to 1693 counts, which is a CPI parameter of 1693 counts per inch. For simplicity, this is called a CPI parameter of 1600 counts per inch.
The gain motion_scaling decreases beyond the limit of 0.19 m/s.
In fact, the wireless transmission protocol used in the illustrated embodiment allows, for each displacement direction x or y, the transmission of 8 signed bits of data every 10 milliseconds, which is 12700 counts (positive or negative) per second. For a CPI value of 1600 CPI, this limit corresponds to a maximum mouse speed in one of the directions x, y of
12700 1693 * 25.4 * 10 - 3
meters per second, which is approximately 0.19 m/s.
The decrease in the gain motion_scaling for speeds exceeding 0.19 m/s allows avoiding overrun problems when transmitting the accumulated value to the central processing unit. The means for adjusting the gain 31 in FIG. 2 thus take into account the bandwidth of the channel used to transmit the value stored in the accumulator to the host device.
For a mouse speed of 0.76 m/s, the gain motion_scaling drops to 8, which is a CPI value of 423 CPI. In fact, in light of the report rate specified in the HID specifications, the maximum mouse speed for a CPI value of 423 CPI is
12700 423 * 25.4 * 10 - 3
meters per second, or approximately 0.76 m/s.
In this example, the value of the motion_scaling varies with the speed by 1/x when the mouse speed is greater than 0.19 m/s. The means for adjusting the gain are therefore designed so that above 0.19 m/s, it uses approximately the maximum bandwidth of the channel for transmitting the value stored in the accumulator to the host device.
Of course, the invention is not limited to such a curve. In particular, one may systematically underutilize the bandwidth of this channel. It is the previous accumulated measurement which serves as the basis for the gain calculation: providing a safety margin avoids an overrun in the channel if the mouse speed increases. The safety margin may for example be fixed, meaning the curve representing the variations in the motion_scaling as a function of the speed has the same appearance as the curve in FIG. 4 , but with the values for the motion_scaling shifted by an identical value.
There may also be linear variations with the speed, or stepwise variations. Depending on the desired application, there may also be a gain motion_scaling for low speeds which is higher or lower than 4*K, a speed limit beyond which the gain motion_scaling decreases differently, etc.
If, for example, the values X, Y read from the accumulator are equal to +42 and −103 counts respectively, for a current motion_scaling of 16, the processor 30 in FIG. 2 may calculate a mouse speed, or at least a value approximately proportional to the mouse speed. The corresponding displacement of the mouse is approximately equal to
( 42 2 + 103 2 ) * 256 16 * 1 32 * 2 * 30 * 10 - 6 ,
which is approximately 3.34 millimeters. If the values X, Y are read at a report rate of 10 milliseconds, this displacement corresponds to a speed of 0.334 m/s. The gain motion_scaling may then be readjusted using this new value for the speed. If one refers to the curve in FIG. 4 , the gain motion_scaling assumes a value of about 18.2.
Thus in 10 milliseconds, the gain motion_scaling increases from a value of 16 to a value of about 18. In order to avoid such variations in gain, one may use an average of the speeds over a longer period, on the order of a tenth of a second for example, or a sum of the displacement measurements accumulated over several read cycles.
In an alternative embodiment not represented in the figures, one may instead readjust the gain at a much higher readjustment frequency, for example, at each acquisition of a displacement measurement (Δx,Δy).
To return to FIG. 2 , the measurement transmitted from the mouse to the central processing unit is received in the processor 25 , inputting the motion captured by the mouse. A driver run by the processor 25 may be used to amplify by a given factor each value for the number of accumulated counts received. The driver also allows moving a pointer 26 on a screen 27 by a number of pixels approximately proportional to the amplified value. The motions of the pointer 26 on the screen are thus approximately proportional to the motion captured by the sensor 22 .
In this embodiment, beyond 0.19 m/s, the gain for the mouse is approximately as high as possible for the bandwidth of the channel between the mouse and the central processing unit. The loss in precision resulting from the quantification into the number of counts is therefore relatively low. In addition, the factor applied by the driver may be relatively low, such that the pointer 26 moves in a relatively precise manner.
It will be appreciated that the various means discussed above could be implemented with hardware, code (software or firmware), or a combination of hardware and code.
The various embodiments described above can be combined to provide further embodiments. Aspects of the embodiments can be modified, if necessary to employ concepts of the various patents, applications and publications to provide yet further embodiments.
These and other changes can be made to the embodiments in light of the above-detailed description. In general, in the following claims, the terms used should not be construed to limit the claims to the specific embodiments disclosed in the specification and the claims, but should be construed to include all possible embodiments along with the full scope of equivalents to which such claims are entitled. Accordingly, the claims are not limited by the disclosure. | A motion capture device for communicating with a host device in order to input captured motion. The device includes an amplifier module structured to weight displacement measurements by a gain, and an adjustment module structured to adjust the gain as a function of a speed of the capture device. | 6 |
CROSS-REFERENCE TO RELATED APPLICATIONS
The present application claims priority under 35 U.S.C. §119 of U.S. patent application No. 60/721,321 filed 27 Sep. 2005, the disclosure of which is expressly incorporated by reference herein in its entirety.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
Not applicable.
REFERENCE TO A COMPACT DISK APPENDIX
Not applicable.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to through air dryer (TAD) fabrics, and more particularly, to TAD fabrics have a composite whereby side fabric portions are woven to the main body portion of the fabric.
2. Background of the Invention
There is continuing need to improve the fabrics used in TAD applications. For typical dryers such as non-TAD, there is a need to alternate standard and, for example, PPS yarns, to prevent tension variation during the heat-setting process. Still further, PPC is used in some fabrics across the entire width of the fabric, and this is very expensive. PPS does not have the same level of tenacity as PET, so a combination is better.
In many TAD machines, the paper that is produced is trimmed at the forming section prior to being transferred to the TAD fabric. At the TAD section, as depicted in FIG. 1 , hot air is blown going through the paper 100 and passing through the fabric 102 and drum 104 . However, as the paper was previously trimmed, there is an area of the fabric 106 that received more air flow at higher temperatures.
The result is that the fabric that is not in contact or otherwise protected by the paper web is exposed to the harsher paper machine running conditions than if the fabric was protected by the web. This result in premature wear or other destruction of the fabric.
Accordingly, a need exists for a TAD fabric having the ability to survive under the harsh environments longer by postponing the wear at the exposed sides of the fabric.
BRIEF SUMMARY OF THE INVENTION
A TAD fabric meeting the needs discussed above is achieved using a composite fabric for through air drying having a fabric body fabricated from a first material and having a first side portion and a second side portion, wherein the first side portion is fabricated from a second material. Similarly, the second side portion can be fabricated using a third material, or the second material and the third material can be the same material.
In prior art TAD applications, part of the fabric is not protected by the paper web. More specifically, the edge portions of the, the edge portions of the fabric, when not in contact or otherwise covered by the web, is exposed to the harsher environment of the paper machine running conditions.
In the present invention, a new edge material is added to the main portion of the fabric. That is, a main central portion of the fabric running in the machine direction has additional side panels added. The paper web generally covers the main middle portion, and overlays, or extends to cover a portion of the side portions.
In the composite fabric, the first side portion is woven to the fabric body along one side edge. The second side portion is woven to the fabric body along a second side edge. The second side edge is opposite the first side edge. The first and second side portions can be woven to the fabric body on the same loom.
Likewise, the first and second portions can have the same weave pattern as the fabric body.
Still further, the first and second side portions can be subjected to the same processing as the fabric body, for example, heat setting, stretching, coating, and the like. When a coating is utilized, the coating, when compared to the composite fabric, has at least one of enhanced release properties, enhanced wear properties and enhanced thermal stability.
The material used for the body of the composite fabric is at least one of polyester and polyethylenepterathalate (PET).
The material used for the first side portion is at least one of polyphenylenesulfide (PPS), polyetheretherketone (PEEK), high temperature and hydrolysis resistant polymers, blends using PPS, blends using PEEK, alloys of PPS, alloys of PEEK, and high temperature nylon. The high temperature nylon is at least one of a variant of nylon 66 and an aromatic nylon.
Additionally, the diameter of the material used for the first side portion can be substantially the same as the diameter of the first material.
When the first side portion is woven to the fabric body, it is preferably woven in the same plane.
It is also preferred that the fabric body and the first side portion have substantially the same CFM throughput. However, depending on the design parameters, the CFM throughput of the first side portion can be different from the fabric body, or may be different from the second side portion.
Additionally, it is preferred that there is a smooth transition between the main portion of the fabric and the side portions.
The size of the first and second side portions is dependent upon the size of the paper web. In the preferred embodiment, the width of the side portions is approximately 20-40 cm when measured in the weft direction.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention is further described in the detailed description which follows, in reference to the noted plurality of drawings by way of non-limiting examples of exemplary embodiments of the present invention, in which like reference numerals represent similar parts throughout the several views of the drawings, and wherein:
FIG. 1 is a cross section of the prior art;
FIG. 2 is a plan view of paper side of the composite fabric of the invention;
DETAILED DESCRIPTION OF THE INVENTION
FIG. 2 depicts a plan view of the composite fabric 10 of the present invention. The composite fabric has a central fabric portion 12 , a first fabric side or outer edge portion 14 , and a second fabric side or outer edge portion. MD indicates the machine direction of the composite fabric.
It is understood that the first fabric side portion 14 and the second fabric side portion 16 are interchangeable, and reference to one may be interchanged with the other. Stated differently, the plan view of FIG. 1 may represent either the paper side or the drum side.
The central portion 12 can be any woven TAD fabric. The material used for the central portion 12 , also known as the body of the composite fabric, is preferably at least one of polyester and polyethylenepterathalate (PET).
The first fabric side portion 14 , or new edge material, is added to the central fabric portion 12 . That is, the central fabric portion of the fabric running in the machine direction has additional side panels 14 , 16 . The paper web 18 generally covers the central fabric portion 12 , and overlays, or extends to cover a portion of the side portions 14 , 16 at first and second paper web overlays 20 , 22 .
In the composite fabric, the first side portion 14 is woven to the central fabric portion 12 along a first side edge 24 . The second fabric side portion 16 is woven to the central fabric portion 12 along a second side edge 26 . The second side edge 26 is opposite the first side edge 24 . The first and second fabric side portions 14 , 16 can be woven to the central fabric body 12 . This weaving of the first and second fabric side portions 14 , 16 to the central fabric body 12 is preferably performed on the same loom on which the central fabric body was woven.
There is no requirement that the first fabric side portion 14 have the same weave pattern as the central fabric portion 12 or the second fabric side portion 16 . In the preferred embodiment, the first and second fabric portions 14 , 16 have the same weave pattern. Additionally, it is preferable that the first and second fabric portions 14 , 16 have the same weave pattern as the central fabric portion 12 .
Still further, the first and second fabric side portions 14 , 16 can be subjected to the same processing as the central fabric portion 12 . For example, heat setting, stretching, coating, and the like. When a coating is utilized, the coating, when compared to a composite fabric without the coating, has at least one of enhanced release properties, enhanced wear properties and enhanced thermal stability.
The material used for the central fabric portion 12 of the composite fabric 10 is preferably at least one of polyester and polyethylenepterathalate (PET).
The material used for the first fabric side portion 14 and/or the second fabric side portion 16 is preferably at least one of polyphenylenesulfide (PPS), polyetheretherketone (PEEK), high temperature and hydrolysis resistant polymers, blends using PPS, blends using PEEK, alloys of PPS, alloys of PEEK, and high temperature nylon. The high temperature nylon is at least one of a variant of nylon 66 and an aromatic nylon.
Additionally, the diameter of first fabric side portion fibers 28 used for the first fabric side portion 14 , and the diameter of second fabric side portion fibers 30 used for the second fabric side portion 16 can be substantially the same as the diameter of the central fabric portion fibers 32 used for the central fabric portion 12 .
When the first side portion is woven to the fabric body, it is preferably woven in the same plane.
It is also preferred that the fabric body and the first side portion have substantially the same CFM throughput. However, depending on the design parameters, the CFM throughput of the first side portion can be different from the fabric body, or may be different from the second side portion.
Additionally, it is preferred that there is a smooth transition between the main portion of the fabric and the side portions.
The size of the first and second fabric side portions 14 , 16 is predetermined and can be based upon the size of the paper web. In the preferred embodiment, the width of each of the fabric side portions 14 , 16 is approximately 10-60 cm when measured in the weft direction, preferably approximately 20-40 cm.
It is noted that the foregoing examples have been provided merely for the purpose of explanation and are in no way to be construed as limiting of the present invention. While the present invention has been described with reference to an exemplary embodiment, it is understood that the words which have been used herein are words of description and illustration, rather than words of limitation. Changes may be made, within the purview of the appended claims, as presently stated and as amended, without departing from the scope and spirit of the present invention in its aspects. Although the present invention has been described herein with reference to particular means, materials and embodiments, the present invention is not intended to be limited to the particulars disclosed herein; rather, the present extends to all functionally equivalent structures, methods and uses, such as are within the scope of the appended claims. | A through air dryer (TAD) fabric having a composite configuration whereby side fabric portions made of a more resistant material are woven to the main body portion of the fabric. Side fabric portions that are not protected from the paper web, and therefore exposed to harsher environmental conditions than the portion of the fabric covered by the paper web, deteriorate faster. By replacing the side portions that are exposed to harsher environment with more resistant material, the TAD fabric will last longer. | 3 |
RELATIONSHIP WITH CO-PENDING APPLICATIONS
This is a continuation-in-part of Ser. No. 605,791 filed Aug. 18, 1975, now abandoned.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to dispensers for surgical threads, and more particularly to a reel and case for storing, holding and dispensing surgical threads.
2. Background of the Invention
During a surgical intervention, there is a need for the surgeon to use thread for ligaturing and suturing. The surgical thread is very frequently packaged as a coil in a protective tube and unwinding it causes a tendency to kink. This kinking is unpleasant, annoys the surgeon, and increases the duration of the intervention. In certain cases, there is a risk of the thread knotting or being damaged as a result of this kinking.
Many designs have been proposed for holding and dispensing surgical threads, including a variety of spool and reel type devices, as illustrated for example in U.S. Pat. Nos. 2,893,548; 2,938,624;, 3,095,159; and 3,376,973. While several of these devices effectively prevent the suture from kinking or tangling as it is being removed from the dispenser, the dispensers tend to be easily dropped or misplaced during use. Some dispensers which are adapted to be slipped over the finger of the practitioner during use tend to interfere with the ligaturing or suturing operation, or are otherwise inconvenient to use.
The present invention remedies these disadvantages by providing a reel and case for surgical thread which is easily and conveniently manipulated by the surgeon and permits the surgical thread to be removed in any length desired by the practitioner, with the other portion remaining in the case for preservation. The case is equipped with a finger element that permits the surgeon to hold it in the palm of his right or left hand according to his needs without reducing the ability to manipulate his fingers.
SUMMARY
The surgical thread dispenser of the present invention comprises a flat, cylindrical reel for holding a surgical thread wound thereon, a case for said reel enclosing the reel on one side and around the outer periphery thereof with an opening in the peripheral rim of the case through which the thread is dispensed from the reel, and a split finger ring affixed to the reel case through an arcuate membrane which enables the practitioner to hold the reel case in the palm of his hand while his fingers remain unencumbered.
BRIEF DESCRIPTIONS OF DRAWINGS
FIG. 1 is a plan view of the dispenser casing;
FIG. 2 is a lateral elevation view cross section in part, taken only line II--II of FIG. 1;
FIG. 3 is an elevation view, cross sectional in part, similar to FIG. 2, but showing the reel in cross section in the casing;
FIG. 4 is a partial view taken along arrow IV of FIG. 1;
FIG. 5 is a cross-sectional view taken along line V--V of FIG. 4;
FIG. 6 is a partial elevation view taken along arrow VI of FIG. 1;
FIG. 7 is a cross-sectional view taken along line VII--VII of FIG. 6.
FIG. 8 is a plan view of the reel;
FIG. 9 is a cross-sectional view taken along line IX--IX of FIG. 8;
FIG. 10 is a cross-sectional view taken along line X--X of FIG. 8.
FIG. 11 is a plan view of the dispenser with reel and surgical thread.
DESCRIPTION OF PREFERRED EMBODIMENTS
In accordance with the present invention, the casing for the reel for surgical threads, such as suture or ligature threads for the surgeon or other practitioner, is characterized in that the casing is composed of a receptacle, generally of a cylindrical shape, comprising a circular backing plate and a rim extending from the periphery thereof, and, in the center of the backing plate, a spindle provided to receive a reel containing the surgical thread, this thread being dispensed from the reel through an opening in the outer rim of the case. The backing plate of the case is extended by a membrane or arcuate tail holding a split ring adapted to be placed on one of the practitioner's fingers.
According to one feature of the invention, the suture dispenser is characterized in that the membrane or arcuate tail is provided with a line of weakness which allows the finger ring to be bent to an angle with the plane of the suture reel and enables the practitioner to easily hold the dispenser in the palm of his hand while retaining complete freedom of his fingers.
With specific reference to FIGS. 1 and 2, the suture casing comprises cylindrically shaped receptacle 20 comprising backing plate 24 and in its center, spindle 21 having substantially the same height as peripheral edge or rim 22. Plate 24 of the receptacle optionally contains a plurality of openings 23 and a circumferential reel support ridge 25 spaced intermediate spindle 21 and rim 22. Plate 24 of the receptacle is extended by arculate membrane 26 having outwardly rounded edge 26a and opposite inwardly rounded or hollowed edge 26b.
Membrane 26 terminates in finger ring 30 of which opposing members 30a and 30b are preferably joined by low strength member 31. Outwardly rounded edge 26a of membrane 26 optionally includes suture retaining element 29 comprising a pair of parallel cuts 28 located intermediate receptacle 20 and finger ring 30.
Membrane 26 is further optionally provided with groove 27 extending transversely across the membrane intermediate receptical 20 and finger ring 30. Groove 27 constitutes a line of weakness along which the membrane may be flexed to provide an angle between the plane of the finger ring and the plane of the receptacle to facilitate holding the suture casing in the palm of the hand of the practitioner.
Peripheral rim 22 of receptacle 20 includes opening 32 through which the surgical thread can pass from the reel to the outside of the casing. Detail of one suitable opening is illustrated in FIG. 4 where elongated opening 32 is centrally located in rim 22 and is provided with slot 36 to allow the suture to be slipped into the opening. Further detail of opening 32 is illustrated in cross section in FIG. 5.
With reference to FIG. 3 and FIGS. 8-10, there is illustrated suture reel 33 comprising two spaced and parallel flange portions joined by central hub 39 which contains axial opening 35. The embodiment of reel 33 illustrated in FIG. 8 includes two openings 34 in web 39 which adapt the reel to fit the pins of a winding machine to facilitate winding the surgical thread upon the reel. Axial opening 35 is sized to fit over spindle 21 of the receptacle to allow reel 33 to turn freely thereon.
With reference to FIGS. 2 and 3, spindle 21 is preferably provided with reel restraining lip 40 to prevent the reel from slipping off spindle 21 once it has been snapped into place. Spindle 21 is also preferably equipped with shoulder 41 at the base thereof to provide a bearing surface for reel hub 39. The distance between shoulder 41 and lip 40 of spindle 21 corresponds to the thickness of hub 39 at axial opening 35. Ridge 25 serves to support reel 33 to facilitate the turning thereof as suture is withdrawn from the reel. Reel 33 is preferably symmetrical in design so that it may be placed into receptacle 20 without regard for a top or bottom.
With reference to FIGS. 6 and 7, there is illustrated a preferred configuration for optional surgical thread holding element 29 which allows the thread to be quickly and surely put into and removed from a fixed position under the holding element during use.
With final reference to FIG. 11, there is illustrated a suture case of the present invention with a length of suture extending therefrom and restrained in the suture holding means in accordance with a preferred use of the invention.
When the practitioner desires to use the reel casing of the present invention, he introduces one finger of his right or left hand into ring 30 and can thus have at his disposal, by pulling slightly on the thread from the reel, the desired length of thread while he is performing an operation.
The dispenser for surgical thread, as above described, is adapted to receive any diameter of ligature and suture threads, of braided or monofilament construction, and of any predetermined length. The construction of the dispenser prevents the unit, thread and casing, from rolling on the operative field when the dressing nurse is working with the surgeon, or even during the utilization of the unit by the surgeon should he temporarily remove it from his finger. It allows the surgeon to hold the unit in the hollow of his right or left hand while providing him free use of his 10 fingers. During the utilization of the thread, the portion of the thread remaining on the reel is afforded maximum protection against suture damage, and the surgeon can check the remaining length of thread since the reel is preferably made of translucent material. There are thus prevented many interferences usually associated with spooled sutures and which are prejudicial to the efficiency of a surgical process.
The surgical thread is not damaged when being removed from the supporting reel or by the thread holding element. The thread starts perfectly free on the reel and, at the end of the winding, it is still free and ready for use.
When the surgeon has finished the operation, he has the ability to free his finger of the dispenser by simply pulling on the casing, which causes the ring to separate by breaking the low strength connecting portion 31, quickly freeing the surgeon's finger.
The holes 23 in the bottom of the casing provide a fast and efficient flow of ethylene oxide or other sterilization fluid when the dispenser unit is sterilized. Such holes may be omitted where the unit is to be sterilized by heat or radiation.
The invention is not restricted to the embodiment shown and described in detail, and various modifications thereof will be apparent to those skilled in the art and be applied thereto without departing from the scope of the present invention. | A surgical thread dispenser comprising a reel for holding the thread wound thereon, a reel case enclosing the reel on one side and around the periphery thereof with an opening in the periphery for dispensing the thread, and a finger ring attached to the casing and adapted so that when the ring is placed over one finger of the surgical practitioner, the reel case is positioned in the palm of the practitioner's hand and lengths of the surgical thread may be conveniently withdrawn from the dispenser. | 3 |
BACKGROUND OF THE DISCLOSURE
[0001] This application claims the priority of Korean Patent Application No. 10-2004-0083537, filed on Oct. 19, 2004, in the Korean Intellectual Property Office, the disclosure of which is incorporated herein in its entirety by reference.
[0002] 1. Field of the Disclosure
[0003] The disclosure relates to a biaxial micro-electro-mechanical system (MEMS) actuator and a method of manufacturing the same, and more particularly to a biaxial actuator for seesaw driving in two directions and a method of manufacturing the same.
[0004] 2. Description of the Related Art
[0005] Optical scanners including biaxial actuators can be used for large displays. The driving speed of a biaxial actuator relates to the resolution of a display device, and the driving angle of the biaxial actuator relates to the screen size of the display device. That is, as the driving speed of a micro mirror increases, resolution is improved. Also, as the driving angle of the micro mirror increases, the screen size of the display device increases. Accordingly, in order to realize large display devices with high resolution, optical scanners including biaxial actuators need to operate at high speed and have a high driving angle.
[0006] However, since the driving speed and the driving angle of the micro mirror are in a trade-off relation, there is a limitation in increasing both the driving speed and the driving angle of the biaxial actuator.
[0007] Optical scanners used for display devices need to operate at high speed, that is, operate at a resonant frequency during horizontal scanning, but need to operate linearly, that is, operate at a non-resonant frequency during vertical scanning.
[0008] Conventional actuators designed for resonant driving are hard to operate at a non-resonant frequency.
SUMMARY OF THE DISCLOSURE
[0009] The present invention may provide a biaxial actuator capable of resonant driving during horizontal scanning and non-resonant linear driving during vertical scanning, and a method of manufacturing the biaxial actuator.
[0010] The present invention may also provide a biaxial actuator having a high driving force and a high driving angle, and a method of manufacturing the biaxial actuator.
[0011] The present invention may also provide a biaxial actuator, which can be manufactured easily, and a method of manufacturing the biaxial actuator.
[0012] According to an aspect of the present invention, there may be provided a biaxial actuator comprising: a stage unit seesawing in a first direction; a first support unit supporting the stage unit; a stage unit driving unit including first driving comb electrodes outwardly extending from opposite sides of the stage unit in the first direction, and first fixed comb electrodes extending from the first support unit facing the first driving comb electrodes such that the first driving and fixed comb electrodes alternate with each other; a second support unit supporting the first support unit such that the first support unit seesaws in a second direction perpendicular to the first direction; and a first support unit driving unit including second driving comb electrodes installed at the first support unit, and second fixed comb electrodes corresponding to the second driving comb electrodes, wherein the first and second driving comb electrodes and the stage unit are formed at a first level, and the first and second fixed comb electrodes are formed at a second level lower than the first level such that the first and second fixed comb electrodes do not overlap with the first and second driving comb electrodes at a vertical plane.
[0013] The stage unit may comprise: a connecting part of which the first driving comb electrodes are formed at an outer surface; and a stage formed at an inner surface of the connecting part.
[0014] The stage may be a circular plate.
[0015] The connecting part may be an oval band having the inner surface to which the stage is connected.
[0016] The first support unit may comprise: a pair of first torsion springs extending from opposite sides of the stage unit in the second direction; and a rectangular moving frame including a pair of first portions parallel to each other and to which the first torsion springs are connected, and a pair of second portions parallel to each other and extending in the second direction, wherein the rectangular moving frame is made up of a first silicon layer to which the first torsion springs are connected, a second silicon layer to which the first fixed comb electrode is connected, and an insulation layer between the first silicon layer and the second silicon layer.
[0017] The second support unit may comprise: a pair of second torsion springs extending from the second portions of the first support unit in the first direction; and a rectangular fixed frame including a pair of second portions parallel to each other to which the second torsion springs are connected, and a pair of first portions parallel to each other extending in the first direction, wherein each of the fixed frame and the second torsion springs is made up of the first silicon layer, the second silicon layer, and the insulation layer.
[0018] The first support unit driving unit may comprise first extending members extending from the first level of the moving frame parallel to the second torsion springs, wherein the second driving comb electrodes extend from the first extending members towards the first portions of the second support unit that face the first extending members, wherein the second fixed comb electrodes extend from second extending members that extend from the second silicon layer of the second support unit to correspond to the first extending members.
[0019] The first and second driving comb electrodes may be electrically connected to each other via the first silicon layer of the second torsion springs, the second silicon layer of the fixed frame may have four electrically isolated portions such that voltage is separately applied to drive the stage unit in the first direction and in the second direction, and the second silicon layer of the moving frame may have two electrically isolated portions such that voltage is separately applied from the second silicon layer of the second torsion springs.
[0020] The biaxial actuator may further comprise: third driving comb electrodes formed at an inner surface of the connecting part; a base formed under the first support unit; and third fixed comb electrodes formed on the base to correspond to the third driving comb electrodes.
[0021] The biaxial actuator may further comprise a conductive layer formed on the base to electrically connect the corresponding first fixed comb electrodes and third fixed comb electrodes.
[0022] The stage unit, the stage unit driving unit, the first support unit, the second support unit, and the first support unit driving unit may be manufactured as one silicon-on-insulator (SOI) substrate.
[0023] The first torsion springs may be meander springs.
[0024] According to another aspect of the present invention, there may be provided a biaxial actuator comprising: a stage unit seesawing in a first direction; a first support unit supporting the stage unit; a stage unit driving unit including first driving comb electrodes outwardly extending from opposite sides of the stage unit in the first direction, and first fixed comb electrodes extending from the first support unit facing the first driving comb electrodes such that the first driving and fixed comb electrodes alternate with each other; a second support unit supporting the first support unit such that the first support unit seesaws in a second direction perpendicular to the first direction; and a first support unit driving unit including second driving comb electrodes installed at the first support unit, and second fixed comb electrodes corresponding to the second driving comb electrodes, wherein the first and second driving comb electrodes and the stage unit are formed at a first level, the first and second fixed comb electrodes are formed at a second level lower than the first level and at a third level higher than the first level such that the first and second fixed comb electrodes do not overlap with the first and second driving comb electrodes at a vertical plane.
[0025] According to still another aspect of the present invention, there may be provided a method of manufacturing a biaxial actuator comprising: (a) preparing a first substrate in which a first silicon layer, an insulation layer, and a second silicon layer are sequentially stacked, and etching the second silicon layer to form a rectangular moving frame portion, first fixed comb electrodes inwardly extending from opposite sides of the moving frame in a first direction, a rectangular fixed frame portion surrounding the moving frame portion, a second torsion spring portion connecting between the moving frame portion and the fixed frame portion in the first direction, and second fixed comb electrodes extending from a first portion of the second silicon layer of the fixed frame portion, parallel to the second torsion spring portion, towards the second torsion spring portion; (b) respectively forming electrode pads on central portions of one opposite sides and the other opposite sides of a glass substrate; (c) etching inner areas of the fixed frame portion on the glass substrate; (d) bonding the second silicon layer of the first substrate on the glass substrate; (e) forming an electrode pad in an area corresponding to the fixed frame portion on the first silicon layer; (f) etching the first silicon layer to form a stage unit, first driving comb electrodes formed at an outer surface of the stage unit to alternate with the first fixed comb electrodes, the moving frame portion, first torsion springs connecting the moving frame portion and the stage unit in a second direction perpendicular to the first direction, the fixed frame portion, the second torsion spring portion, and second driving comb electrodes extending from an extending member extending from the first silicon layer of the moving frame parallel to the second torsion spring portion to alternate with the second fixed comb electrodes; and (g) etching an exposed insulation layer.
[0026] According to yet another aspect of the present invention, there may be provided a method of manufacturing a biaxial actuator comprising: (a) preparing a first substrate in which a first silicon layer, an insulation layer, and a second silicon layer are sequentially stacked, and etching the second silicon layer to form a rectangular moving frame portion, first fixed comb electrodes inwardly extending from opposite sides of the moving frame in a first direction, a rectangular fixed frame portion surrounding the moving frame portion, a second torsion spring portion connecting between the moving frame portion and the fixed frame portion in the first direction, second fixed comb electrodes extending from a first portion of the second silicon layer of the fixed frame portion, parallel to the second torsion spring portion, towards the second torsion spring portion, and third fixed comb electrodes formed inside the moving frame and extending in the first direction; (b) respectively forming electrode pads on central portions of one opposite sides and the other opposite sides of a glass substrate, and forming a conductive layer connecting the first fixed comb electrodes and the third fixed comb electrodes; (c) etching an upper portion between the fixed frame portion and the moving frame portion in the glass substrate such that a lower portion of the fixed frame portion and the moving frame portion are connected; (d) bonding the second silicon layer of the first substrate on the glass substrate; (e) grinding a lower portion of the glass substrate by CMP to separate a portion attached to the fixed frame portion from a portion attached to the moving frame portion; (f) forming an electrode pad in an area corresponding to the fixed frame portion on the first silicon layer; (g) etching the first silicon layer to form a stage unit including a stage and a connecting part of which the stage is formed at an inner surface, first driving comb electrodes formed at an outer surface of the connecting part to alternate with the first fixed comb electrodes, third driving comb electrodes formed at an area inside the connecting part to alternate with the third fixed comb electrodes, the moving frame portion, first torsion springs connecting the moving frame portion and the connecting part in a second direction perpendicular to the first direction, the fixed frame portion, the second torsion spring portion, and second driving comb electrodes extending from an extending member extending from the first silicon layer of the moving frame parallel to the second torsion spring portion to alternate with the second fixed comb electrodes; and (h) etching an exposed insulation layer.
BRIEF DESCRIPTION OF THE DRAWINGS
[0027] The above and other features and advantages of the present invention will become more apparent by describing in detail exemplary embodiments thereof with reference to the attached drawings in which:
[0028] FIG. 1 is a schematic perspective view of a biaxial actuator according to a first embodiment of the present invention;
[0029] FIG. 2 is a plan view of the biaxial actuator of FIG. 1 ;
[0030] FIG. 3 is a sectional view of the biaxial actuator taken along line III-III of FIG. 2 ;
[0031] FIG. 4 is a sectional view of the biaxial actuator taken along line IV-IV of FIG. 2 ;
[0032] FIG. 5 is a sectional view of the biaxial actuator taken along line V-V of FIG. 2 ;
[0033] FIG. 6 is a plan view for explaining an electrical path of the biaxial actuator of FIG. 2 ;
[0034] FIG. 7 is a timing diagram obtained when a voltage is applied to the biaxial actuator according to the first embodiment of the present invention;
[0035] FIG. 8 is a sectional view of a biaxial actuator according to a second embodiment of the present invention;
[0036] FIGS. 9 and 10 are schematic sectional views of a biaxial actuator according to a third embodiment of the present invention;
[0037] FIGS. 11A through 11E are sectional views illustrating steps of manufacturing a base substrate;
[0038] FIGS. 12A through 12C are sectional views illustrating steps of manufacturing a lower part of a main body structure; and
[0039] FIGS. 13A through 13F are sectional views illustrating steps of manufacturing an upper part of the main body structure when the lower structure and the main body structure are combined.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0040] The present invention will now be described more fully with reference to the accompanying drawings, in which preferred embodiments of the invention are shown. The sizes of elements shown in the drawings may be exaggerated, if needed, or sometime the elements may be omitted for a bettering understanding of the present invention. However, such ways of description do not limit the scope of the technical concept of the present invention.
[0041] FIG. 1 is a schematic perspective view of a biaxial actuator according to a first embodiment of the present invention. FIG. 2 is a plan view of the biaxial actuator of FIG. 1 . FIGS. 3 through 5 are sectional views respectively taken along lines III-III, IVIV, and V-V of FIG. 2 .
[0042] Referring to FIGS. 1 and 2 , a stage unit may include a stage 100 that has a mirror (not shown) formed on a surface thereof, and a connecting part 110 . The stage 100 may be a circular plate with a minimum area for light reflection. The connecting part 110 may be an oval band, and the stage 100 may be connected to an inner circumferential surface in a direction of the shorter diameter of the connecting part 110 . The reason why such a circular stage 100 may be used is to reduce the load of the stage 100 and increase a driving force.
[0043] The connecting part 110 may be supported by a first support unit including first torsion springs 210 and a rectangular moving frame 200 such that the connecting part 110 can seesaw in a first direction (X-direction). The first torsion springs 210 may be meander springs.
[0044] The first support unit may be supported by a second support unit including second torsion springs 310 and a rectangular fixed frame 300 such that the first support unit can seesaw in a second direction (Y-direction) perpendicular to the first direction. Accordingly, the stage 100 supported by the first support unit and the second support unit may move in two directions.
[0045] In detail, the stage 100 may be connected to the rectangular moving frame 200 via the two first torsion springs 210 that may be formed in the second direction. Accordingly, the stage 100 may be supported to seesaw around the first torsion springs 210 . Further, since the first torsion springs 210 are meander springs, the length of second portions 200 y of the moving frame 200 , which will be explained later, may be reduced and a driving angle at a non-resonant frequency may increase.
[0046] The first torsion springs 210 may be respectively connected to centers of first portions 200 x of the rectangular moving frame 200 . The second torsion springs 310 may be respectively connected to centers of the second portions 200 y of the rectangular moving frame 200 . The rectangular moving frame 200 may include the two first portions 200 x that are parallel to each other and extend in the first direction, and the two second portions 200 y that may be parallel to each other and extend in the second direction. The rectangular fixed frame 300 may surround the rectangular moving frame 200 . The rectangular fixed frame 300 may include first portions 300 x that may extend in the first direction, and second portions 300 y that may extend in the second direction. The second torsion springs 310 connected to the centers of the second portions 200 y may also be connected to centers of the second portions 300 y of the rectangular fixed frame 300 . The second torsion springs 310 may extend in the first direction. Accordingly, the moving frame 200 may be supported to seesaw around the second torsion springs 310 .
[0047] As shown in FIGS. 1 and 3 , the moving frame 200 , the fixed frame 300 , and the second torsion springs 310 may be a multi-tiered structure having multiple layers 201 , 202 , and 203 , 301 , 302 , and 303 , and 311 , 312 , and 313 . The multi-tiered structure may be a silicon-on-insulator (SOI) substrate including highly doped first silicon layers 201 , 301 , and 311 , second silicon layers 203 , 303 , and 313 , and SiO 2 insulation layers 202 , 302 , and 312 between the first silicon layers and the second silicon layers. Reference numerals 204 and 304 denote a first base and a second base, respectively, which may be insulation substrates, such as glass substrates. The multi-tiered structure will be understood through an explanation about a method of manufacturing an actuator according to the present invention.
[0048] A stage unit driving unit causing the stage 100 to seesaw, as shown in FIGS. 3 through 5 , may include first driving comb electrodes 120 formed outside the connecting part 110 and the first fixed comb electrodes 220 extending from the second silicon layer 202 of the moving frame 200 to alternate with the first driving comb electrodes 120 , and third driving comb electrodes 130 formed inside the connecting part 110 and third fixed comb electrodes 250 being formed on the first base 204 to correspond to the third driving comb electrodes 130 . Since the fixed comb electrodes may be vertically formed and the corresponding comb electrodes may extend from different level of silicon layers from each other, the comb electrodes may be easily manufactured as it will be described later, and electrical paths may be easily formed.
[0049] In the meantime, a first support unit driving unit that causes the first support unit to seesaw may be interposed between the moving frame 200 and the fixed frame 300 . As shown in FIGS. 1 and 2 , first extending members 230 may extend from the first silicon layer 201 of the second portions 200 y of the moving frame 200 toward the second portions 300 y of the fixed frame 300 that is connected to the second portions 200 y by the second torsion springs 310 . Second driving comb electrodes 240 may be formed at a side surface of the first extending members 230 . Second extending members 340 may extend from the second silicon layer 303 of the fixed frame 300 to correspond to the first extending members 230 . Second fixed comb electrodes 350 may be formed on a side surface of the second extending members 340 facing the first extending members 230 to correspond to the second driving comb electrodes 240 . The comb electrodes 240 and 350 alternate with each other as shown in FIG. 4 , and extend from silicon layers of different levels.
[0050] In the present embodiment, at least three electrical paths may be needed for the motion of the stage 100 , and three electrical paths may be needed for the motion of the moving frame 200 . Here, when the ground is maintained at the same electric potential, five electrical paths may be needed. FIG. 6 is a plan view of the actuator of FIG. 2 for explaining an electrical path of the actuator. In FIG. 6 , black portions 601 and 602 are electrically isolated portions, and reference numerals P 1 , P 2 , P 3 , P 4 , and P 5 denote electrode pads for wiring with an external circuit. The electrode pads P 2 through P 5 are disposed between two electrically isolated portions 601 .
[0051] Referring to FIG. 6 , the first electrode pad P 1 may be disposed on the second portions 300 y (at the left side on the drawing), and electrically connected to the first through third driving comb electrodes 120 , 130 , and 240 via the first silicon layer 311 of the second torsion springs 310 and the first torsion spring 210 . Here, the first pad P 1 may act as a virtual ground. The second and third pads P 2 and P 3 may be electrically connected to the second silicon layer 303 of the first portions 300 x of the fixed frame 300 that may be electrically isolated by the electrically isolated portions 601 . Accordingly, an electrical circuit for producing an electrostatic force may be formed between the second fixed comb electrodes 350 and the second driving comb electrodes 240 . Meanwhile, the fourth pad P 4 and the fifth pad P 5 are electrically connected between the second silicon layer 303 of the second portions 300 y of the fixed frame 300 and the second silicon layer 313 of the second torsion springs 310 . The fourth pad P 4 and the fifth pad P 5 may be electrically connected to the moving frame 200 via the second silicon layer 313 of the second torsion springs 310 . The second silicon layers 203 of the two second portions 200 y of the moving frame 200 to which the fourth and fifth pads P 4 and P 5 are connected may be electrically separated by the electrically isolated portions 602 . The fourth and fifth pads P 4 and P 5 may be connected to the fixed comb electrodes 220 via the second silicon layer 313 of the second torsion springs 310 , and the third fixed comb electrodes 250 , as shown in FIG. 4 , may be electrically connected to the first fixed comb electrodes 220 by a conductive layer 206 formed on the first base 204 .
[0052] The operation of the biaxial actuator according to the present embodiment will now be explained in detail.
[0053] First, if a predetermined voltage is applied to the electrode pad P 5 when the electrode pad P 1 is at a ground voltage, the stage 100 may seesaw in a positive x-direction due to an electrostatic force between the first and third fixed comb electrodes 220 and 250 and the first and third driving comb electrodes 120 and 130 . In contrast, if the predetermined voltage is applied to the electrode pad P 4 , the stage may seesaw 100 in a negative x-direction.
[0054] Further, if a predetermined voltage is applied to the electrode pad P 2 , the stage 100 is driven in a negative y-direction due to an electrostatic force between the second driving comb electrodes 240 and the second fixed comb electrodes 350 . If the predetermined voltage is applied to the electrode P 3 , the stage 100 is driven in a positive y-direction. Accordingly, the stage 100 can be driven in two directions.
[0055] FIG. 7 is a timing diagram when a voltage is applied to the biaxial actuator of the present invention.
[0056] Referring to FIG. 7 , a sine wave pulse voltage with a 180-degree phase shift was applied to the electrode pads P 2 and P 3 for a horizontal scanning (see FIG. 7A ). A triangular wave voltage with a 180-degree phase shift was applied to the electrode pads P 4 and P 5 for a vertical scanning in two directions (see FIG. 7B ). A step pulse was applied to the electrode pads P 4 and P 5 in case of vertical scanning in one direction (see FIG. 7C ). Here, a frequency of 22.5 kHz was used for the horizontal scanning, and a frequency of 60 Hz was used for the vertical scanning to perform a non-resonant linear driving. The second torsion springs 310 are designed such that a resonant frequency is approximately 1 kHz or more for the linear driving of the vertical scanning. According to results obtained using the ANSYS program, a driving angle was 8° or more when a drivingfrequency was 22.5 kHz in the horizontal scanning, and a resonant frequency was 1200 Hz in the vertical scanning. A driving angle was 4.5 to 5.0° when the driving frequency was 60 Hz in the vertical scanning.
[0057] FIG. 8 is a sectional view of a biaxial actuator according to a second embodiment of the present invention. The actuator may be structured such that the third driving comb electrodes 130 , the third fixed comb electrodes 250 , the first base 204 , and the conductive layer 206 that electrically connects between the first fixed comb electrodes 220 and the third fixed comb electrodes 250 are removed from the actuator shown in FIG. 4 .
[0058] An actuator according to a third another embodiment of the present invention shown in FIGS. 9 and 10 further includes a driving unit that is disposed on a stage unit and drives the stage in two directions.
[0059] FIGS. 9 and 10 are schematic sectional views of the actuator according to a third embodiment of the present invention. The same elements as those in the first embodiment may be given the same reference numerals, and a detailed explanation thereof will not be given.
[0060] Referring to FIGS. 2, 9 , and 10 , on the basis of a first level on which a stage unit and driving comb electrodes are formed, the same structure of the second level of the first embodiment may be formed on the first level. That is, a moving frame 200 ′, a fixed frame 300 ′, and second torsion springs 310 ′ are made of a multi-tiered structure having multiple layers 201 , 202 , 203 , 202 ′, and 203 ′, 301 , 302 , 303 , 302 ′, and 303 ′, and 311 , 312 , 313 , 312 ′, and 313 ′. The multi-tiered structure may be an SOI substrate having highly doped first silicon layers 201 , 301 , and 311 , second silicon layers 203 , 303 , and 313 , third silicon layers 203 ′, 303 ′, and 313 ′, and first insulation layers 202 , 302 , and 312 and second insulation layers 202 ′, 302 ′, and 312 ′ between the silicon layers. Reference numerals 204 , 304 , and 204 ′ respectively denote first through third bases, which may be insulation substrates, such as glass substrates.
[0061] First through third fixed comb electrodes 220 ′, 350 ′, and 250 ′, second extending members 340 ′ are formed at a third level over the first level to respectively correspond to first through third fixed comb electrodes 220 , 350 , and 250 , second extending members 340 formed at the second level under the first level. A conductive layer 206 ′ is formed on the third level to correspond to a conductive layer 206 .
[0062] The actuator of the present embodiment, as shown in FIG. 10 , is driven in two directions by applying a ground voltage Vg to the driving comb electrodes and voltages V 1 through V 4 to electrodes that are formed on the second and third levels to be point-symmetric about the stage 100 . Since voltage is simultaneously applied to the fixed electrodes that are diagonally formed, the actuator of the third embodiment has a higher driving force than the actuator of the first embodiment, and can be driven more stably.
[0063] A method of manufacturing an actuator according to a fourth embodiment of the present invention will now be explained in steps. In the present embodiment, a method of manufacturing the actuator of the first embodiment will be exemplarily explained below. Through the description of the manufacturing method, the detailed structure of the actuator of the first embodiment will be more clearly understood. The constituent elements shown in FIGS. 1 through 6 are cited with reference numerals, if necessary.
[0064] 1. Manufacture of Base Substrate
[0065] Referring to FIG. 11A , after a Pyrex glass 400 with a thickness of 400 μm is prepared, a photoresist 402 may be patterned on the glass 400 to expose portions corresponding to electrode pads P 4 and P 5 and a conductive layer 206 .
[0066] Although not shown, predetermined portions corresponding to electrode pads P 2 and P 3 may also be exposed.
[0067] Referring to FIG. 11B , the portions exposed by the photoresist 402 may be etched to a depth of approximately 2000 Å, and then, the photoresist 402 may be removed.
[0068] Referring to FIG. 11C , an Au/Cr film may be deposited on the glass 400 to a thickness of 4000/200 Å and then may be patterned to form the electrode pads P 2 through P 5 and the conductive layer 206 (for the electrode pads P 2 and P 3 , see FIG. 6 ).
[0069] Referring to FIG. 11D , a dry film resist (DFR) film may be coated on the glass 400 to cover electrodes, and then, may be patterned. An opening portion 404 a corresponds to an area between a fixed frame 300 and a moving frame 200 of an actuator.
[0070] Referring to FIG. 11E , exposed portions of the Pyrex glass 400 may be etched by sand blasting, and the DFR film 400 may be removed to complete a glass base substrate 400 . Here, the portions subjected to sand blasting may be partially etched such that the glass base substrate 400 may be integrally formed.
[0071] 2. Manufacture of Lower Part of Main Body Structure
[0072] Referring to FIG. 12A , as an upper structure material, a silicon-on-insulator (SOI) substrate 500 in which an SiO 2 insulation layer 502 with a thickness 1 to 2 μm may be formed as an etch stop layer between a first silicon layer 501 and a second silicon layer 503 may be prepared. A photoresist mask 504 having a predetermined shape may be formed on the second silicon layer 503 . Here, portions covered by the mask 504 may be a third fixed comb electrode portion W 1 , a first fixed comb electrode portion W 2 , a moving frame portion W 3 , a second extending member portion W 4 , a fixed frame portion W 5 , and a second fixed comb electrode portion (not shown) extending from the fixed frame portion W 5 .
[0073] Referring to FIG. 12B , portions on the second silicon layer 503 , which are not covered by the mask 504 , may be etched in an Inductively Coupled Plasma Reactive Ion Etching (ICPRIE) method to expose the insulation layer 502 through exposed areas of the mask 504 . After etching is completed, the mask 504 may be removed by stripping.
[0074] Referring to FIG. 12C , third fixed comb electrodes 250 , first fixed comb electrodes 220 , the moving frame 200 , second extending members 340 , and a fixed frame 300 may be formed on the insulation layer 502 , and second fixed comb electrodes 350 extends from the fixed frame 340 .
[0075] 3. Bonding between Base Substrate and Lower Part of Main Body Structure and Manufacture of Upper Part of Main Body Structure
[0076] Referring to FIG. 13A , the substrate 500 from which the second silicon layer 503 is etched may be bonded to the glass base substrate 400 obtained through the above-described process. An anodic bonding may be used herein and the second silicon layer 503 contacts the glass base substrate 400 . Here, a portion of the electrode pads P 2 through P 5 may be exposed from the fixed frame 300 . Next, a top surface of the first silicon layer 501 may be grinded by a chemical mechanical polishing (CMP) method to a thickness of approximately 70 μm.
[0077] Referring to FIG. 13B , the glass substrate 400 may be grinded by CMP to separately form an inner glass substrate (i.e., a first base 204 ) and an outer glass substrate (i.e., a second base 304 ).
[0078] Referring to FIG. 13C , an Au/Cr film may be deposited on the first silicon layer 501 to a thickness of 4000/200 □, and then patterned to form an electrode pad P 1 .
[0079] Referring to FIG. 13D , a photoresist mask 506 having a predetermined shape may be formed on the first silicon layer 501 . Here, portions covered by the mask 506 may be a stage portion W 6 , a connecting part portion W 7 , a first driving comb electrode portion W 8 , a moving frame portion W 9 , a first extending member portion W 10 , a fixed frame portion W 11 , and second and third driving comb electrode portions (not shown).
[0080] Referring to FIG. 13E , portions on the first silicon layer 501 , which are not covered by the mask 506 , may be etched by ICPRIE to expose the insulation layer 502 through exposed areas of the mask 506 .
[0081] Referring to FIGS. 13F , the insulation layer 502 exposed by the mask 506 may be removed. Then, the mask 506 may be removed. A stage 100 , a connecting part 110 , first driving comb electrodes 120 , the moving frame 200 , first extending members 230 , a fixed frame 300 , second and third driving comb electrodes 240 and 130 may be formed.
[0082] Next, if the actuator is used as an optical scanner, a reflective layer (not shown) having a reflexibility of 99% or more may be formed on a top surface of the stage 100 to minimize a damage due to laser beams.
[0083] Although the method of manufacturing the actuator of the first embodiment has been explained, since methods of manufacturing the actuators of the second and the third embodiments can be performed according to the fourth embodiment, a detailed explanation thereof will not be given.
[0084] As described above, the actuator according to the present invention may seesaw in two directions, and may include the stage unit driving unit that drives the stage in a resonant manner in the first direction and the first support unit driving unit that drives the first support unit in a non-resonant linear manner in the second direction. Therefore, the biaxial actuator may be used as an optical scanner for a display that requires a high speed horizontal scanning and a linear vertical scanning.
[0085] In the meantime, the method of manufacturing the actuator according to the present invention electrically separate the torsion springs used in the vertical scanning as double lines, such that an upper line can be used as an electrical path for the driving comb electrodes and a lower line can be used as an electrical path for the fixed comb electrodes. Furthermore, since the driving comb electrodes and the fixed comb electrodes may be formed at different levels, the biaxial actuator may be easily manufactured, thereby reducing manufacturing costs.
[0086] While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it will be understood by those of ordinary skill in the art that various changes in form and details may be made therein without departing from the spirit and scope of the present invention as defined by the following claims. | Provided are a biaxial actuator and a method of manufacturing the same. The biaxial actuator includes: a stage unit seesawing in a first direction; a first support unit supporting the stage unit; a stage unit driving unit including first driving comb electrodes outwardly extending from opposite sides of the stage unit in the first direction, and first fixed comb electrodes extending from the first support unit facing the first driving comb electrodes such that the first driving and fixed comb electrodes alternate with each other; a second support unit supporting the first support unit such that the first support unit seesaws in a second direction perpendicular to the first direction; and a first support unit driving unit including second driving comb electrodes installed at the first support unit, and second fixed comb electrodes corresponding to the second driving comb electrodes, wherein the first and second driving comb electrodes and the stage unit are formed at a first level, and the first and second fixed comb electrodes are formed at a second level lower than the first level such that the first and second fixed comb electrodes do not overlap with the first and second driving comb electrodes at a vertical plane. | 7 |
This application is a continuation of application Ser. No. 043,372, filed on Apr. 28, 1987, now U.S. Pat. No. 4,788,556.
BACKGROUND OF THE INVENTION
This invention relates to methods and apparatus for the elimination of dissolved air from ink used in an ink jet apparatus and, more particularly, to a new and improved method and apparatus for deaerating ink in a highly effective manner.
In many ink jet systems, ink is supplied to a chamber or passage connected to an orifice from which the ink is ejected drop-by-drop as a result of successive cycles of decreased and increased pressure applied to the ink in the passage, usually by a piezoelectric crystal having a pressure-generating surface communicating with the passage. If the ink introduced into the passage contains dissolved air, decompression of the ink during the reduced pressure portions of the pressure cycle may cause the dissolved air to form small bubbles in the ink within the passage. Repeated decompression of the ink in the chamber causes these bubbles to grow and such bubbles can produce malfunctions of the ink jet apparatus.
Heretofore, it has been proposed to supply deaerated ink to an ink jet apparatus and maintain the ink in a deaerated condition by keeping the entire supply system hermetically sealed using, for example, flexible plastic bags or pouches as a deaerated ink supply. Such arrangements are not entirely satisfactory, however, because the flexible plastic pouches are at least partially air-permeable and, in hot melt ink systems, this problem is aggravated because the plastic pouch material becomes more permeable to air at elevated temperatures at which the heated ink is capable of dissolving large amounts of air, e.g., up to 20 percent by volume. Moreover, air may dissolve into the ink at the ink jet orifice during periods of non-jetting. Such dissolved air may diffuse through the ink into the jet pressure chamber, and thereby cause malfunction of the jet. Consequently, air bubble formation in the ink jet head of a hot melt jet apparatus is a primary cause of hot melt ink jet failure.
Accordingly, it is an object of the present invention to provide a new and improved method and apparatus for eliminating dissolved air from ink in an ink jet system which overcomes the above-mentioned disadvantages of the prior art.
Another object of the invention is to provide a system for deaerating ink in an ink jet system and for purging any air bubbles which have been formed in the ink jet head.
SUMMARY OF THE INVENTION
These and other objects of the invention are attained by subjecting ink in an ink jet system to reduced pressure applied through a membrane which is permeable to air but not to ink. In one form of the invention, ink is conveyed to an ink jet head through a passage which communicates through a permeable membrane with a plenum maintained at a reduced air pressure. To eject any air bubbles which may have been formed prior to removal of dissolved air, the permeable membrane may be flexible and an increased air pressure may be applied to the membrane which raises the pressure on the ink in the jet, causing expression of such ink and thus purging the jet of air bubbles.
In a particular embodiment, the ink supply leading to the ink jet head includes a deaerating passage in which the ink is formed into an elongated thin layer between two opposite wall portions and at least one of the wall portions comprises a flexible, air-permeable membrane covering a plenum in which the air pressure may be reduced or increased. In addition, a check valve is provided upstream from the deaerating passage so that increased pressure in the plenum will eject ink and any trapped air bubbles from the ink jet head. Within the ink jet head, ink is circulated by convection from the orifice to the deaerating passage.
BRIEF DESCRIPTIONS OF THE DRAWINGS
Further objects and advantages of the invention will be apparent from reading of the following description in conjunction with accompanying drawings, in which:
FIG. 1 is a block diagram, partly in section, schematically illustrating a representative embodiment of an ink jet ink supply including an ink deaerator in accordance with invention; and
FIG. 2 is an en cross-sectional view of the ink deaerator used in the ink supply system of FIG. 1.
DESCRIPTION OF PREFERRED EMBODIMENT
In the typical embodiment of the invention illustrated in the drawings, an ink jet apparatus includes an ink supply reservoir 10 holding liquid ink for use in an ink jet head 11 from which ink is ejected to produce a desired pattern on a sheet or web 12 of paper or other image support material in the usual manner. The ink jet head 11 is supported by conventional means for reciprocal motion transverse to the web 12, i.e., perpendicular to the plane of FIG. 1, and the web is transported by two sets of drive rolls 13 and 14 in the direction indicated by the arrow past the ink jet head.
The ink supply system includes an ink pump 15 for transferring ink from the ink supply 10 through a flexible supply line 16 to a reservoir 17 which is supported for motion with the ink jet head 11. If hot melt ink is used in the ink jet apparatus, the ink supply system may be of the type described in the Hine et al. U.S. Pat. application Ser. No. 043,369, filed Apr. 28, 1982, for "Hot Melt Ink Supply System", now U.S. Pat. No. 4,814,786 assigned to the same assignee as the present application. In that ink supply system ink is transferred from the ink supply 10 to the reservoir 17 only when the level of the ink 18 in the reservoir is low.
To maintain the ink in the reservoir 17 at atmospheric pressure, a vent 19 is provided. Accordingly, the ink 18 standing in the reservoir 17 contains air even if the ink was protected from air in the ink supply 10. Moreover, when hot melt inks are used, as much as 20 percent by volume of air may be dissolved in the ink. If ink containing such dissolved air is subjected to the periodic decompression which takes place in the ink jet head 11, air bubbles can form in the ink, causing failures in the operation of the ink jet head.
To overcome this problem in accordance with the present invention, an ink deaerator 20 is provided in the ink supply path between the reservoir 17 and the ink jet head 11. An air pump 21 is connected through a flexible air line 22 to provide increased or reduced air pressure to the ink deaerator. The ink deaerator 20 is mounted for reciprocal motion with the ink jet head 11 and the reservoir 17, and, in the illustrated embodiment, the air pump 21 is operated by engagement of a projectable pump lever 23 with a projecting lug 24 on the deaerator 20 during the reciprocal motion of the deaerator.
The pump lever 23 is connected to a piston 25 within the pump arranged so that, if negative pressure is to be provided to the deaerator, the pump lever will be engaged during motion of the deaerator in one direction, causing the piston to move in a direction to apply reduced pressure through the line 22, after which the piston may be locked in position. If increased pressure is to be applied to the deaerator, the lever 23, together with the piston 25, is moved in the opposite direction by the lug 24.
The internal structure of the deaerator 20 and the ink jet head 11 is shown in the sectional view of FIG. 2. At the lower end of the reservoir 17 a check valve 26 is arranged to permit ink to pass from the reservoir to a narrow elongated deaerating passage 27 which leads to two passages 28 and 29 in the ink jet head 11 through which ink is supplied to the head. In a particular embodiment, the passage 27 is about 0.04 inch thick, 0.6 inch wide and 31/2 inches long and is bounded by parallel walls 30 and 31 which are made from a flexible sheet material which is permeable to air but not to ink. The material may, for example, be a 0.01 inch thick layer of medical grade silcone sheeting such as Dow Corning SSF MEXD-174.
On the other side of the membranes 30 and 31 from the passage 27, air plenums 32 and 33, connected to the air line 22, are provided. Each plenum contains a membrane support 34 consisting, in the illustrated example, of a corrugated porous sheet or screen, to support the membrane when the pressure within the plenum is reduced. The air pump 21 is arranged to normally maintain pressure within each plenum at less than about 0.75 atmosphere and, preferably at about 0.4 to 0.6 atmosphere. In addition, the length and width of the passage 27 are selected so that, during operation of the ink jet head, the ink being supplied thereto is subjected to a reduced pressure within the passage for at least about one half minute and, preferably for at least one minute. With this arrangement, enough dissolved air is extracted through the membranes 30 and 31 from the ink within the passage to reduce the dissolved air content of the ink below the level at which bubbles can be formed in the ink jet head.
The membranes 30 and 31 and the plenums 32 and 33 are also arranged to expel ink which may contain air bubbles through the orifice 35 in the ink jet head 11 when operation of the system is started after a shut-down. For this purpose the air pump 21 is arranged as described above to supply increased pressure through the line 22 to the deaerator 20. This causes the flexible membranes 30 and 31 to move toward each other. Since the check valve 26 prevents ink from moving back into the reservoir 17, the ink in the passage 27 is forced into the ink jet head 11, expelling any ink therein which may contain air bubbles through the ink jet orifice 35.
In order to deaerate ink in the ink jet head 11 which may have dissolved air received through the orifice 35, a heater 36 is mounted on the rear wall 37 of an ink jet passage 38 which leads from the passages 28 and 29 to the orifice 35. When the heater 36 is energized, ink in the passage 38 which may contain dissolved air received through the orifice 35 during inactive periods in the operation of the jet is circulated continuously by convection upwardly through the passage 38 and then through the passage 29 to the deaerating passage 27. In the deaerating passage 27 the ink is deaerated as it moves downwardly to the passage 28, and it then returns through the passage 28 to the passage 38.
In operation, ink from the reservoir 17, which contains dissolved air, is transferred to the ink jet head 11 through the passage 27 as the ink jet head operates. The reduced pressure in the plenums 32 and 33 causes dissolved air in the ink to be extracted from the ink through the membranes 30 and 31. As the deaerator 20 moves in its reciprocal motion, the air pump 21 is operated by the lug 24 and lever 23 to maintain reduced pressure in the plenums. When it is necessary to expel ink from the ink jet head on start-up of the system, the air pump 21 is arranged to supply increased pressure to the plenums 32 and 33. During nonjetting periods of the ink jet head, the ink circulates convectively through the passages 38, 29, 27 and 28, transporting ink which may contain air from the orifice 35 to the deaerator.
Although the invention has been described herein with reference to a specific embodiment, many modifications and variations therein will readily occur to those skilled in the art. For example, the permeable membrane and air plenum may form one wall of an ink reservoir. Accordingly, all such variations and modifications are included within the intended scope of the invention as defined by the following claims. | In the particular embodiment of an ink deaerator described in the specification, an elongated ink path leading to an ink jet head is formed between two permeable membranes. The membranes are backed by air plenums which contain support members to hold the membranes in position. Reduced pressure is applied to the plenums to extract dissolved air from the ink in the ink path. Increased pressure can also be applied to the plenums to eject ink from the ink jet head for purging. Within the ink jet head ink is circulated convectively from the orifice to the deaerating path even when the jet is not jetting ink. | 1 |
BACKGROUND OF THE INVENTION
This invention relates to hollow fiber membrane modules and more specifically, to all thermoplastic hollow fiber membrane modules and methods for manufacturing such modules.
Hollow fiber microfiltration membrane devices have found many applications in the pharmaceutical, food, beverage and semiconductor industries. These devices have the unique feature of requiring no support structures for the membrane media since, as a result of its tubular geometry, the membrane is self supporting. This feature provides numerous benefits, one of which is the ability to pack a large membrane area in a very small volume. An additional benefit is that this geometry provides a minimum of obstructions in the flow path which decreases hydraulic inefficiencies as well as reduces contamination from the support structures present in conventional devices. This latter feature is of particular value, for example, in semiconductor industry filtration applications where it is essential to maintain extremely low levels of particle contamination and extractable contaminants.
In spite of the numerous advantages that hollow fiber membrane devices possess over flat-sheet membrane devices, they have yet to be used in some critical applications. In the past, hollow fiber devices have suffered from a major disadvantage, namely, that two-part adhesive resins have been used as potting material to seal the hollow fibers into the filtration device. These resins are a persistent source of organic extractable contaminants as well as particulate matter resulting from shedding due to the gradual hydrolysis and deterioration of the adhesive resin. In addition, such resins are chemically incompatible with many organic solvents. As a result of these shortcomings, hollow fiber membrane devices have been widely used in applications involving aggressive (corrosive) chemicals, organic solvents and where purity is essential.
Another difficulty in the potting of hollow fibers is non-uniformity in the fiber bundle prior to potting. Since the adhesive resin has to flow into the bundle to form an integral seal, the more open spaces have a tendency to fill faster while the rest of the spaces remain substantially free of adhesive; this results in non-integral bundles. To alleviate this problem, an excessive amount of adhesive resin may be used but this sometimes results in wicking of the adhesive along the length of the fiber which ultimately reduces the amount of useful filtration area.
Those skilled in the art of making hollow fiber modules have therefore searched for ways to overcome these difficulties. Some manufacturers have eliminated the use of two-part adhesives by using a molten thermoplastic polymer to seal the fiber bundle; others have developed techniques to obtain a uniform spacing between fibers prior to potting. Significant effort has been directed toward forming a reliable seal around the hollow fibers which make up the module.
In order to seal a hollow fiber membrane module to prevent the fluid to be filtered from bypassing the membranes, the sealing material must completely surround the hollow fiber without damaging it (i.e. either by collapsing the lumen or by destroying the structural integrity of the walls of the fiber adjacent to the sealing area). In order to assure complete coverage when using adhesive resins, this material must have a low viscosity when it is forced into the interstitial spaces between the fibers. Thus reactive polymer solutions which are initially of low viscosity but later become a solid are used. Due to its relatively high viscosity, it is impossible to force a molten polymer into these spaces without collapsing or otherwise damaging the hollow fiber. Alternatively, lowering the viscosity requires using relatively high temperatures, typically higher temperatures than those which the hollow fibers can withstand without damage. Nonetheless, there are several prior art references which disclose processes for the fabrication of an all-thermoplastic hollow fiber module.
U.S. Pat. No. 5,015,585 (Robinson) describes a process for making a homopolymer hollow fiber module by thermal bonding techniques which first requires insertion of a metal rod into the lumen of each hollow fiber to maintain its shape and integrity during the bonding process. These strengthened hollow fibers are conventionally potted by immersing the fibers into a mold containing a suitable molten thermoplastic. Using this technique, the spaces between the hollow fibers are filled or otherwise melted while keeping the lumens of the fibers open. After bonding is completed, the rods inserted into the fibers are forced through the ends and removed; this is followed by cutting the bundle end to create a through hole for communicating with the interior of the fiber lumen. While Robinson suggests that any thermoplastic polymer can be used to produce a homopolymer module, the disadvantage with this technique is the difficulty in reliably and efficiently inserting a rod into each hollow fiber, which in a typical filtration module can amount to several thousand fibers.
U.S. Pat. Nos. 4,980,060 and 5,066,397 (Muto et al) disclose another process for thermoplastically sealing the ends of a hollow fiber filtration module by first dipping the fiber ends into an inorganic cement (e.g. gypsum) thereby filling a portion of the lumens and allowing it to set. A bundle of fibers is then gathered and the filled ends are potted using a molten thermoplastic resin. Alternatively, the filled ends may be directly fusion bonded together to form the requisite seal. The bonding step is followed by conventionally cutting of the ends and finally dissolving the cement inside the lumen ends with a suitable chemical. This technique is not universally applicable since inorganic cements must be found that do not damage the membrane either by themselves or by the solvent required for their removal. Finally, this technique is undesirable due to the difficulty of the steps involved as well as the potential contamination resulting from the inorganic cement which may not totally be removed.
U.S. Pat. No. 5,228,992 (Degen) discloses a process for enhancing the ends of thermoplastic hollow fibers, e.g. by radiation cross-linking, in order to increase the fiber's ability to withstand the high temperature inherent in injection molding techniques. The ends are subsequently potted by a conventional molding technique. The difficulty with Degen's process is that the fibers have to be specially treated at the ends to render them more stable at high temperatures. Furthermore, cross-linking is not suitable for some polymers, for example fluoropolymers.
All of the aforementioned techniques require a special treatment of the ends of the hollow fibers to render them resistant to the high temperatures necessary to pot the bundle, temperatures so high that the fiber would normally collapse or otherwise completely melt. Additionally, these techniques require that the fiber be processed as single entities rather than as a grouped array.
Other processes have been devised which focus on producing a more uniform bundle. U.S. Pat. No. 5,186,832 (Mancusi et al) discloses a method for producing a uniform bundle by first converting the hollow fibers into a fabric with the fibers transversely oriented, in a spaced-apart, mutually parallel relationship and held in place by warp filaments. The device is assembled by spirally winding the fabric made out of hollow fibers to obtain a uniformly-spaced fiber bundle. In this process the fiber bundle is sealed using conventional resinous potting material. In addition to conventional potting methods, this patent discloses a technique for simultaneously applying resinous potting material to the ends of the bundle as the woven fabric is wound rather than subsequently potting the bundle after winding. However, no mention is made of sealing the fiber ends with a molten thermoplastic polymer. In fact, this patent cautions that heat generated by exothermic resinous potting material is to be avoided, otherwise the hollow fibers may be damaged. Thus the use of adhesive resins in the process taught by the '832 patent suffers from all the disadvantages mentioned above. In addition, holding the fiber bundle together by means of warp filaments is a potential source of particulate contamination downstream of the active filter area, which is highly undesirable in certain applications such as semiconductor manufacturing processes. Also, the space resulting from the use of warp filaments results in a lower packing density and hence less active filtration area for a given bundle volume.
More recently, U.S. Pat. No. 5,284,584 (Huang et al) discloses techniques for fabricating an all thermoplastic, spirally wound hollow fiber membrane cartridge. Like the Mancusi et al patent (U.S. Pat. No. 5,186,832), Huang et al teaches first preparing a fabric array with transversely oriented warp filaments used to create a uniform spaced-apart bundle of mutually parallel fibers. Thus this patent suffers from the same disadvantages in this regard as discussed with respect to Mancusi et al. Huang et al describes details of the fabrication of tubesheets at the ends of the fiber bundle to form a fluid-tight seal around the fibers such that when the fiber bundle is fitted into a housing there will be no fluid flow which bypasses the membranes. While this patent discloses extruding a molten thermoplastic resin as the fabric array is wound on a mandrel, Huang et al teaches that the resin and the hollow fiber membrane material must be chosen so that the melting point of the molten resin must be at least 10° C., and preferably 20° C., below the melting point of the hollow fibers. More specifically, this patent teaches that the temperature of the molten resin at the point of contact with the hollow fiber must be lower than the melting point of the fiber. This limits the uses to which such membranes can be put. For example, the use temperature for a device of this sort will be limited to that established by the lower temperature resin melting point.
Thus despite numerous prior attempts, there still exists a need for improvements in the art of designing and efficiently manufacturing a reliable hollow fiber membrane module which is both chemically and mechanically robust and which has essentially no possibility of shedding undesired particulate contaminants or producing other extractables.
SUMMARY OF THE INVENTION
The present invention overcomes the limitations and disadvantages of the prior art by providing a unique hollow fiber membrane module fabricated from superior hollow fiber polymeric materials with individual membranes reliably and reproducibly sealed with chemically compatible thermoplastic polymers. Through the use of manufacturing methods designed to optimize the incorporation of these superior hollow fiber materials, an improved module can be constructed without the need for extraneous material which could create undesired particulate contaminants or without the complicated use of lumen-stiffening rods. The end product made according to the process of the invention is an all thermoplastic module having an integral bundle with reliable, fluid-tight seals. The improved hollow fiber membrane module according to the invention exhibits superior structural and chemical integrity, thermal stability, purity and cleanliness, factors which permit the device to be used in a wide variety of demanding applications, such as filters used in the manufacture of microelectronic components.
While suitable for use with a wide variety of hollow fiber-molten thermoplastic polymer systems, the preferred aspect of the present invention involves forming a plurality of hollow fiber membranes into a parallel array, with the membranes being made from high molecular weight (i.e. molecular weight>500,000 Daltons) polymers. The array is contacted with an extrusion of molten thermoplastic polymer of much lower molecular weight (e.g. molecular weight<200,000 Daltons) at a contact temperature which is higher than the melting point of the membrane polymer. The molten polymer can thus be applied with sufficiently low viscosity to assure adequate penetration of the polymer around the individual fibers of the array. At the same time, the high molecular weight hollow fiber membrane polymer assures that, despite melting of the hollow fiber wall, there will be no lumen collapse or other deformation which would violate the integrity of the hollow fiber membrane element.
In preferred embodiments, the hollow fiber polymer and the molten polymer are homopolymers, i.e., the monomer composition of the two polymers is substantially the same. Since the two polymers are chemically identical, they fuse together during the sealing cycle to form a single phase material in the tubesheet. The high degree of interpenetration resulting from applying the extruded polymer at temperatures higher than the melting point of the fiber creates a bond which is stronger than conventional sealing techniques.
In other preferred embodiments, the array is spirally wound about an axis parallel to the longitudinal axis of the hollow fibers while molten polymer is applied to the ends of the array to form an integral bundle of fibers, This bundle with its tubesheet is then suitably prepared for mounting into a cartridge.
It is an object of this invention to construct an all thermoplastic hollow fiber membrane module of robust design able to withstand high temperature and corrosive environments without compromising the cleanliness of the module thereby contaminating the filtration process.
It is a further object of this invention to describe a process which is universally applicable, especially for the manufacture of homopolymer hollow fiber membrane devices.
It is yet another object of this invention to devise a process which is reliable and easily scaleable regardless of the module or hollow fiber dimensions.
Other aspects, objects and advantages of the present invention will become apparent from the following detailed description taken together with the drawings.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective diagram of the apparatus used in the process of making an array of hollow fiber membranes in accordance with a preferred embodiment of the present invention;
FIG. 2 is a top view of a finished array of hollow fiber membranes used in carrying out the process of FIG. 1;
FIG. 3 is a schematic representation of the apparatus used in the process of making hollow fiber membrane modules in accordance with a preferred embodiment of the present invention;
FIG. 4 is a detailed view, in perspective, showing the spiral winding sealing aspect of the hollow fiber membranes by the application of molten thermoplastic in accordance with a preferred embodiment;
FIG. 5 is a photograph of the cross section of a tubesheet of the hollow fiber membrane module manufactured by using the spiral winding technique of FIG. 4; and
FIG. 6 is a sectional view of a hollow fiber membrane module constructed in accordance with a preferred embodiment mounted in a cartridge filter housing.
DETAILED DESCRIPTION OF THE INVENTION
To meet the demands imposed on membrane separation devices in today's critical separations applications (e.g. semiconductor manufacturing), the membranes themselves must exhibit excellent chemical resistance, mechanical strength and thermal stability. This is particularly the case with filtration modules which use hollow fiber membranes as the separation element; moreover, such hollow fibers must be reliably sealed together at one or more ends prior to assembly of the module.
In accordance with the present invention, applicant has discovered that, with the proper choice of hollow fiber membrane materials, it is possible to construct a superior separation module capable of filtering, for example, high purity chemicals at elevated temperatures. The hollow fibers of the present invention are made from polymers of the high molecular weight (i.e. molecular weight>500,000 Daltons) variety. Examples of typically used polymers are: polypropylene, polyethylene and polytetrafluorethylene.
In a preferred embodiment, the hollow fiber membranes are prepared from ultrahigh molecular weight polyethylene (UPE) (i.e. molecular weight>1,000,000 Daltons) in accordance with the processes described in commonly assigned U.S. Pat. Nos. 4,778,601 and 4,828,772, whose disclosures are hereby incorporated by reference. Although there is no acknowledged universal definition of UPE, it is generally distinguished from other members of the polyethylene family, such as high density polyethylene, because UPE exhibits no measurable flow in its molten state despite the fact that UPE does undergo a certain amount of deformation when heated above its melting point. Surprisingly, applicant has found that molten UPE is able to withstand the stresses imparted during sealing without further significant deformation to the fiber and importantly without collapsing the lumen. The UPE fibers constructed as above have a pore size of from 0.05 to 10 microns, an inner diameter of 500 microns and a wall thickness of 200 microns.
The process of fabricating a hollow fiber membrane separation module according to the preferred embodiment of the invention begins with the construction of an array formed of suitable UPE hollow fiber membrane materials manufactured in accordance with the teachings of U.S. Pat. Nos. 4,778,601 and 4,828,772. The technique for forming such an array is generally shown in FIG. 1. A length of hollow fiber 11 membrane is first formed into an array 21 of individual membrane elements arranged substantially parallel to one another. In the fabrication of the array, care must be taken to minimize contamination of the hollow fiber membranes. Contamination may result from the inadvertent addition of extraneous materials to the fibers during the formation of the array by the equipment used to make the array such as a loom. Contamination may also result from materials intentionally added to the array during its assembly such as tie fibers. It is preferable that any materials added to the fibers in the formation of the array be confined to areas which will be trimmed from the finished hollow fiber module.
The array 21 is fabricated by winding a continuous length of hollow fiber membrane 11 on a rotating mandrel 12 having a circular cross section. The circumference of the mandrel is chosen to be an integer multiple of the desired length of the hollow fiber membrane elements which are to comprise the finished array. The mandrel is driven by a controller 13 capable of controlling both the rotational speed of the mandrel and the tension applied to the hollow fiber membrane. The controller includes a fiber feed mechanism 14 which moves a pulley 15 parallel to the central axis of the mandrel and guides the hollow fiber membrane as it is being wound to control the spacing between adjacent fiber segments. The wound hollow fiber membrane is arranged in a single layer, with the windings being substantially parallel to one another either in contiguous contact with, or spaced uniformly apart from, one another.
When the appropriate length of hollow fiber membrane 11 is accumulated on the mandrel 12, the controller 13 stops the winding operation and one or more strips of an adhesive tape 22 are applied to the outer surface of the hollow fiber membrane segments positioned along the length of the mandrel in an orientation parallel to its axis of rotation and perpendicular to the central axes of the individual hollow fiber segments. More than one strip of tape can be used, the circumferential spacing between strips being equal to the desired axial length of the membrane fibers in the array 21. The tape extends from the first hollow fiber membrane segment wound on the mandrel to the last and preferably extends about 1 cm. beyond each end of the fiber array.
A cutting guide (not shown) may be used to slit the hollow fiber membrane segments along the middle of the entire length of the tape 22 such that the hollow fiber membranes 11 remain joined together by the now halved strip of tape. In this manner, one or more hollow fiber membrane arrays are produced, with the fiber elements being secured to one another at their ends by the tape thereby making it easily removed from the mandrel 12. It should be noted that, in this discussion, the edges 23 of the rectangular hollow fiber membrane array 21 are defined as the two surfaces formed by the end portions of the individual hollow fiber membrane elements comprising the array; the ends 24 of the array are defined by the outermost surfaces of the first and last hollow fiber membrane elements in the array. FIG. 2 shows in plan view an array formed in accordance with the above procedures. In cases where one fiber array does not contain a sufficient number of hollow fibers to fabricate a hollow fiber membrane module of the desired membrane area, the arrays may be spliced together end-to-end by means of an adhesive or other bonding mechanism to form a larger array. Any number of arrays may be so spliced together in the manner described above to form a larger array having tape extensions at the edges of both ends of the array.
The next operation in the fabrication of a hollow fiber membrane module is the winding of the fiber array into a bundle and the corresponding formation of a pair of tubesheets 43 at one or more of the edges 23 of the array 21. This process is shown schematically in FIGS. 3 and 4. A single screw extruder 31 is used to feed a thermoplastic sealing polymer to a dual slot extrusion die 32 which produces two polymer extrusions 35 in the form of a ribbon. A suitable length of thermoplastic tube 41 is mounted on a removable winding mandrel 42 positioned below the extrusion die, with the rotational axis of the mandrel being parallel to a line connecting the two outlets of the extrusion die. Stepper motors (not shown) are used to adjust the speed of rotation and distance between the mandrel and the die. A set of gas heaters 33 mounted on a retractable slide (not shown) are used to preheat the tube 41 prior to the fabrication of the tubesheets. The functions of the various elements described above are regulated by a programmable, microprocessor-based controller 34.
In order to maintain the molten thermoplastic polymer extrusion 35 from the die at a uniform temperature, it is preferred to operate the extruder 31 at a constant speed. Maintaining a uniform fiber spacing and tubesheet width requires that the fiber feed rate remain constant and that the distance between the extrusion die and contact point of the polymer extrusion and tubesheet 43 remain constant. The previously described controller 34 in conjunction with the apparatus discussed above accomplish this result with feedback control mechanisms known to those skilled in the art.
Before the winding of the array 21 and the formation of the tubesheets 43, the tube 41 must be pre-heated using the heaters 33. This step is necessary to obtain a good bond between the tubesheet and the tube. Rotation of the winding mandrel 42 and tube is begun and the gas heaters are activated such that a hot gas stream impinges on the portions of the tube where the tubesheets will be formed. After a suitable time, the heaters are removed and the polymer extrusions 35 are applied to the tube.
Following the accumulation of approximately a one-half turn of the polymer extrusions 35 on the tube 41, the leading edge of the hollow fiber membrane array 21 is positioned under and parallel to the tube with the adhesive side of the extended strip of tape 22 facing the tube. The tape is then brought into contact with the tube outboard of the tubesheets 43 and allowed to wind up on the tube as the rotational speed and position of the winding mandrel 42 and tube are adjusted by the process controller 34. A slight tension is maintained on the hollow fiber array to keep the fibers in contact with the polymer extrusions. As the trailing edge of the array is wound up, the tape extensions are fastened to the previous fiber layer to form a fiber bundle 44. Application of the polymer extrusions may be terminated after the entire array is wound about the mandrel. Alternatively, the tubesheets may be built up to a larger diameter depending on the requirements of the rest of the module assembly process. In this case, the rotation of the winding mandrel continues as the molten tubesheets are allowed to cool. The end portions of the sealed fiber bundle can be trimmed to expose the fiber lumens and further machining may be performed to provide a means for sealing the fiber bundle into a suitable housing or the fiber bundle may be contoured to provide details suitable for thermoplastically bonding it to the components of a pressure housing of the same or a similar resin material in order to produce a hollow fiber module. FIG. 5 shows, in cross section, a tubesheet manufactured by the spiral winding technique described above.
In some instances, the cutting of the tubesheet ends obstructs the opening of some of the hollow fiber lumens with a thin web of the thermoplastic sealing resin. These obstructions can be readily removed by heating them above the melting point of the resin thereby causing the thermoplastic resin to fuse into the tubesheet. Heating may be accomplished with either a radiant heater or hot gas stream directed at the obstructed lumens.
Contrary to the prevailing view that excessive heating of the hollow fibers is to be avoided when sealing with molten thermoplastics (see, for example, the aforementioned Huang et al patent), applicant has discovered that it is possible to apply a molten polymer to form a tubesheet at a temperature much higher than that of the melting point of the hollow fiber. In a preferred embodiment, UPE hollow fiber membranes are sealed by application of either high density or low density molten polyethylene at contact temperatures greater than the peak melting point of the UPE fiber. The preferred range of contact temperatures depends on the nature of the sealing resin; contact temperatures in excess of 90° C. above the melting point of the fiber have been successfully used. Table 1 lists a number of polyethylene sealing polymers and summarizes the results obtained with these sealing polymers.
TABLE 1______________________________________ Die Die Melting Point °C. Temperature TemperatureSample Type Initial Peak °C. °C.______________________________________Hollow Fiber UPE 126.8 137.5 N/A N/ADowlex 2503 LLDPE 115.0 126.7 210-212 185Dowlex 2553 LLDPE 118.1 128.5 230-232 207-209Dow 10062N HDPE 127.3 137.5 260-262 215-225______________________________________
Applying the thermoplastic polymer at such elevated temperatures offers several advantages. Since the polymer's viscosity is substantially lowered, it is possible to penetrate freely enough around the fiber bundle before the polymer cools (and hence solidifies) to effect a reliable seal. Furthermore, in the case of a homopolymer construction a strong bond is obtained between the fiber and the tubesheet because the fiber fuses into the molten sealing resin.
The effect of the high temperature application of the thermoplastic is best shown in FIG. 5. The high temperature has caused the UPE fibers to melt, which can be shown under increased magnification by the absence of the porous membrane structures in the vicinity of the thermoplastic sealing polymer. As shown, there has been no resulting flow of fiber material and subsequent deformation of the lumen.
FIG. 6 shows the details of the fiber bundle 44 and corresponding tubesheets 43 (labeled in this figure as 43b and 43t to represent the bottom and top orientations shown in the drawing) which have been assembled into a homopolymer hollow fiber module. This can be accomplished by employing conventional methods of fusion bonding of plastic components. After fabrication of the bundle 44 is completed, the bottom tubesheet 43b is bonded to an inside cap 71. During use, the filtrate collected at that tubesheet is directed to a top end-cap 72 through the tube 41. The housing shell and the top tubesheet 43t of the bundle are simultaneously bonded to the top end-cap. Finally, an outside end-cap 73 is bonded to the bottom of a housing shell 74. Suitable connectors are also added to provide means of connecting the module to a feed and to an effluent line. By these means an integral, homopolymer module free of O-ring seals can be produced.
EXAMPLES
A UPE hollow fiber membrane, 800 to 850 microns in outside diameter and with a lumen diameter of 450 microns, was fabricated into an array and sealed with various molten polyethylene resins as listed in Table 1 according to the foregoing description of the invention. A Brabender Model No. 2503, 3/4" extruder with a 25:1 length to diameter ratio and a 3:1 compression ratio was used to deliver molten polymer to a dual ribbon extrusion die. The extruder was powered by a Brabender Prepcenter Model D-52 drive unit with extruder temperature regulation provided by a Model 808-2504 controller. The extrusion die had two rectangular orifices, each 3 cm. wide and 0.04 cm. thick; the orifices were spaced 9 cm. apart. The distance between the extrusion die and contact point of the ribbons and tubesheet was maintained at approximately 1 cm. by the winding mandrel controller. An Inframetrics Model No. 600 infra-red scanner was used to measure the temperature of the extruded ribbons exiting the die and at the point of contact with the tubesheet.
The tubesheets produced according to the foregoing procedure were examined by sectioning and subsequent photography. The results showed that, although the temperature of the extruded polyethylene ribbons and tubesheet was well above the melting point of the UPE hollow fibers as detailed in Table 1, the fibers within the tubesheet maintained their tubular shape and the lumens remained open. See, for example, the photograph of FIG. 5.
To confirm that the extruded thermoplastic polymer created a reliable seal, the fabricated array with tubesheets was exposed to an aerosol challenge integrity test. According to this test, the bundle or finished module was challenged with a submicron aerosol with the passage of aerosol being monitored downstream of the membrane. A submicron solid particle aerosol was generated using a TSI Model 3076 Constant Output Atomizer to produce a deionized water aerosol; the aerosol was dryed by adding 9 volumes of clean dry dilution air and electrostatic charges were neutralized with a TSI Model 3012 Aerosol Neutralizer. Particle detection was accomplished by a TSI Model 7610 Cleanroom CPC (condensation particle counter) with particle counts displayed on a TSI Model 7130 Remote Processor. The total aerosol flow rate was about 35 slpm with a particle concentration>10 4 particles/cm 3 (>10 7 particles/liter). The bundles made in this example were all integral as evidenced by the complete absence of particles in the air downstream of the tubesheet.
ALTERNATE EMBODIMENTS
Although the embodiments heretofore described have involved the formation of an array of hollow fiber membrane elements prior to sealing with a molten thermoplastic, the principles of the present invention are equally applicable to the formation of an array one fiber at a time. In this instance, a mechanical "pick-and-place" mechanism would be employed to feed a single fiber to a location beneath an extruder such that the polymer extrusion simultaneously creates a seal and forms the array by repeating this process until an array of desired size is created.
Various other configurations of pre-constructed fiber arrays are also possible. For example, the fibers do not have to be positioned perpendicularly to the longitudinal axis of the array. Fiber array bundle arrangements may also vary in that single-ended tubesheets for short length membrane modules may be fabricated as well as multiple tubesheets. In the former case, the hollow fiber elements must be sealed at the opposite end of the tubesheet. In the latter case, intermediate tubesheets, used primarily as support members, may or may not form integral seals around the hollow fiber membranes for particularly long modules. Furthermore, multiple bundles may be produced simultaneously using integrally sealed, multiple tubesheets which are subsequently cut to form individual fiber bundles. Still further, planar laminated arrays are also contemplated to be within the purview of this invention, in which case rectangular fiber arrays may be mounted on top of one another. The use of woven arrays is also possible.
With regard to the manufacture of a finished module, other means for sealing the bundle to the module may be employed, as for example, with the use of O-rings.
Also, the sealing resin has been described throughout as a pure thermoplastic polymer. However, mixtures of thermoplastic polymers, having additives such as viscosity reducing agents or dilutents and adhesive agents, may be used and are intended to be covered under the definition of "thermoplastic polymer."
Additional modifications will become apparent to those of skill in the art without departing from the scope of the present invention as defined in the accompanying claims. | A hollow fiber membrane module and its method of manufacture are disclosed wherein the module is fabricated utilizing superior hollow fiber materials, namely high molecular weight (i.e. molecular weight>500,000 Daltons) polymers. In a preferred embodiment, the hollow fibers are fabricated from ultra-high molecular weight polyethylene (UPE). An array of UPE hollow fiber membranes is contacted with an extrusion of molten thermoplastic polymer at a contact temperature which is higher than the UPE membrane polymer. This high temperature application of sealing polymer does not collapse or otherwise deform the lumen of the hollow fiber, while assuring that the polymer can thus be applied with sufficiently low viscosity to provide adequate penetration around the individual fibers of the array to form an integral seal thereabout. | 1 |
[0001] The present invention relates to a method and apparatus for use in the hydrocarbon exploration and production industry and in particular to a method and apparatus for monitoring a fluid that is to be transported through a fluid conduit. The monitoring of a fluid to be transported through a fluid conduit provides a dynamic indication of the occurrence of detrimental effects for the fluid flow within the conduit. The described method and apparatus have particular application for preventing blockages within fluid umbilicals, although the methods and apparatus may also be adapted for monitoring fluids for the occurrence of detrimental effects within pipelines, wellbores and risers.
[0002] During the production and transportation of hydrocarbons, it is common for the interiors of fluid conduits, including pipelines, wellbores, risers and umbilicals, to become fouled. This fouling can lead to the build up of layers of debris or particulate matter on the inside of conduits, which reduces the effective inner diameter (ID) of the conduit and thus reduces the flow rate. Fouling can also produce blockages in the fluid conduits which completely prevent fluid flow.
[0003] A fluid umbilical is a bundled collection of steel and/or thermoplastic tubing and electrical cabling. Typically they are employed to transmit chemicals, hydraulic fluids, electric power, and two-way data communication and control signals between surface production facilities and subsea production equipment. Umbilicals typically range up to 10 inches (254 mm) in diameter, with internal tubes ranging from 0.5 inch to 1 inch (12.7 mm to 25.4 mm) in diameter. A dynamic umbilical is the portion of the umbilical that is suspended from a semi-submersible vessel to the seabed, where it is coupled to a static section of the umbilical. In a typical umbilical, the multiple internal conduits are twisted together into a helical rope-like structure in order to increase the tensile strength. This is a particularly important consideration for the dynamic umbilical section since it must withstand stresses due to its own weight and the dynamic loading from currents.
[0004] Examples of some of the most frequently transmitted chemicals through umbilicals within the hydrocarbon exploration and production industry include: scale inhibitors; corrosion inhibitors; methanol, ethanol, ethylene glycol, mono ethylene glycol, MEG (examples of hydrate inhibitors); industrial methylated spirits; wax inhibitors and pour point depressants (PPD); low dosage hydrate inhibitors (LDHIs); asphaltene inhibitors and dispersants; flow improvers and surfactants; biocides; H 2 S scavengers; and demulsifiers.
[0005] The relatively small diameters of the internal tubes within the subsea umbilical, in combination with the fact that their helical path arrangement significantly increases the frictional drag experienced by objects inserted into the internal tubes, means that umbilicals are particularly prone to blockages. Such blockages completely prevent fluid transmission through the umbilical and so can cause considerable disruption to production activities. Furthermore, the helical path arrangement of the internal conduits means that conventional cleaning equipment is often prohibited from being inserted to attempt to clear a blockage. If a blockage cannot be removed then this results in obvious time and cost implications for the operator. It is estimated that the costs incurred in replacing a typical subsea fluid umbilical run into several millions of pounds.
[0006] In order to mitigate the risk of blockages forming within umbilicals it is known in the art to provide the internal tubes with a filter at its entrance. Such filters do help prevent certain particulates and other debris from entering the internal tubing. However, in practice it is found that the major contributing factor to the formation of blockages within a fluid umbilical is human error, either through the poor design of the chemical bunkering systems, unsuitable methodologies being employed in offshore environments or even faulty chemical compatibility testing being carried out. For example, if an operator accidentally allows incompatible fluids to be transmitted down the same internal tube then coagulation or flocculation may take place so resulting in blockages within the umbilical. Some examples of known incompatible fluid combinations include:
1) Scale inhibitors and methanol or glycols. If the scale inhibitor is water based (as is normally the case) then methanol or a glycol will precipitate the inhibitor; 2) Pour point depressants and methanol or glycols. When the level of methanol or glycol is above a certain level then precipitation of some polymer PPDs occurs; 3) Asphaltene inhibitors and methanol; 4) Asphaltene dispersants and polar solvents (e.g. alcohols, glycols or water); 5) Flow improvers for water and polar solvents; 6) Flow improvers for oil and any of the other above listed transmitted chemicals; 7) H 2 S scavengers and methanol or organic solvents; and 8) Biocides and methanol.
[0015] A further detrimental effect that occurs within fluid conduits is the onset of corrosion. The effects of corrosion can be exacerbated by the chemical nature of the fluid supply being transported through the conduit. Corrosion can ultimately lead to structural failures within a fluid conduit and therefore it is obviously beneficial to be able to monitor the detrimental effects of corrosion within a fluid conduit.
[0016] It is therefore an object of an aspect of the present invention to provide a method and apparatus for monitoring a fluid that is to be transported through a fluid conduit so as to provide a dynamic indication of the occurrence of detrimental effects for the fluid flow within the conduit.
[0017] It is a further object of an aspect of the present invention to provide a method and apparatus for monitoring the formation of a blockage within a fluid conduit system.
[0018] A yet further object of an aspect of the present invention to provide a method and apparatus for monitoring the level of corrosion within a fluid conduit system.
[0019] The described method and apparatus is applicable to a wide range of fluid conduit systems used in the hydrocarbon exploration and production industry, and in particular to fluid umbilicals.
SUMMARY OF INVENTION
[0020] According to a first aspect of the present invention there is provided a method for monitoring a fluid supply to be transported through a fluid conduit located within a hydrocarbon exploration and production installation, the method comprising the steps of:
providing a monitoring zone upstream of the fluid conduit; introducing the fluid supply to the fluid conduit via the monitoring zone; and monitoring the fluid supply within the monitoring zone so as to detect the occurrence of one or more events detrimental to the flow of the fluid supply through the fluid conduit.
[0024] It is advantageous to monitor the fluid supply prior to entering the fluid conduit as this allows for the early detection of an event detrimental to the flow of the fluid supply e.g. a chemical reaction indicative of corrosion of the fluid conduit or the formation of a potential blockage within the fluid conduit. In this way the risk of costly blockages or structural failure occurring within the fluid conduit is significantly reduced.
[0025] Most preferably the step of monitoring the fluid supply within the monitoring zone comprises the step of detecting solids or solidification within the fluid supply.
[0026] Preferably the method further comprises the step of shutting off the fluid supply to the fluid conduit when solidification is detected. Shutting off the fluid supply to the fluid conduit allows an operator to check the installation to see if a non-compatible chemical supply has been introduced to the fluid supply.
[0027] Optionally the step of detecting solids or solidification within the fluid supply comprises monitoring a pressure differential across a filter located within the monitoring zone. A change in the pressure differential across the filter is indicative of a change in the viscosity within the fluid supply and hence a possible contamination of the fluid supply.
[0028] Preferably the step of shutting off the fluid supply to the fluid conduit occurs when the pressure differential across the filter is outside of a predetermined tolerance value for the fluid supply.
[0029] Most preferably the step of monitoring the pressure differential across the filter further comprises the step of correlating the monitored pressure differential with a temperature of the fluid supply. By correlating the pressure differential across the filter with the temperature of the fluid supply reduces the risk of erroneous contamination events being detected.
[0030] Optionally, the step of detecting solids or solidification within the fluid supply comprises the step of monitoring the water content of the fluid supply.
[0031] Preferably the step of shutting off the fluid supply to the fluid conduit occurs when the water content of the fluid supply is outside a predetermined tolerance value for the fluid supply.
[0032] Optionally, the step of detecting solids or solidification within the fluid supply comprises the step of monitoring a particulate or debris content of the fluid supply.
[0033] Preferably the step of shutting off the fluid supply to the fluid conduit occurs when a density or mass of the particulate or debris content within the fluid supply is outside a predetermined tolerance value for the fluid supply.
[0034] If the fluid supply to the fluid conduit is shut down then an alarm may be activated to notify an operator of the shut down event. Optionally an automated electronic notification may also be sent to an appropriate preselected person notifying them of the shut down event.
[0035] Preferably the step of monitoring the fluid supply within the monitoring zone further comprises the step of analysing the quality or purity of the chemical composition of the fluid supply.
[0036] Optionally the step of monitoring the fluid supply within the monitoring zone further comprises the step of monitoring the rate of flow of the fluid supply.
[0037] Preferably the method further comprises the step of notifying an operator of the risk of a blockage occurring within the fluid conduit when the quality or purity of the chemical composition of the fluid supply is outside a predetermined tolerance value.
[0038] Optionally the method further comprises the step of recording information relating to one or more of the monitored parameters. Recording information regarding fluid cleanliness, viscosity, water content, differential pressure, absolute pressure, temperature and fluid flow rates allows for historical data reviews to be generated.
[0039] According to a second aspect of the present invention there is provided a method for monitoring a fluid supply to be transported through a fluid umbilical, the method comprising the steps of:
providing a monitoring zone upstream of the fluid umbilical; introducing the fluid supply to the fluid umbilical via the monitoring zone; and monitoring the fluid supply within the monitoring zone so as to detect the occurrence of one or more events detrimental to the flow of the fluid supply through the fluid umbilical.
[0043] Embodiments of the second aspect of the invention may comprise preferred and optional features of the first aspect of the invention and vice versa.
[0044] According to a third aspect of the present invention there is provided a fluid monitoring unit for monitoring a fluid supply to a fluid conduit, the fluid monitoring unit comprising a monitoring zone and a sensor, the sensor providing a means for detecting the occurrence of one or more events within the monitoring zone detrimental to the flow of the fluid supply through the fluid conduit, wherein the monitoring zone is configured to provide upstream fluid cooperation with an entrance of the fluid conduit.
[0045] By having the monitoring zone configured to provide upstream fluid cooperation with an entrance to the fluid conduit allows the fluid monitoring unit to dynamically monitor the fluid supply prior to entering the fluid conduit. This allows for the early detection of potential blockage forming scenarios and so significantly reduces the risk of costly blockages occurring within the fluid conduit.
[0046] Most preferably the sensor comprises a filter located within the monitoring zone and a pressure detector arranged to monitor the pressure differential of the fluid supply across the filter.
[0047] Preferably the sensor further comprises a thermometer arranged to provide a means for the fluid monitoring unit to correlate changes in the monitored pressure differential across the filter with temperature changes of the fluid supply.
[0048] Alternatively, or in addition, the sensor comprises a hygrometer arranged to monitor the water content of the fluid supply.
[0049] Alternatively, or in addition, the sensor comprises a particulate sensor arranged to monitor the fluid supply transmitted through the monitoring zone for the presence of particulate or debris.
[0050] The particulate sensor may comprise an optical particulate sensor. The particulate sensor may comprise a passive-induction particulate sensor.
[0051] Alternatively, or in addition, the sensor comprises a UV spectrometer arranged to monitor the chemical composition of the fluid supply transmitted through the monitoring zone.
[0052] Alternatively, or in addition, the sensor comprises a flow meter arranged to monitor the rate of flow of the fluid supply.
[0053] Most preferably the fluid monitoring unit comprises a computer processing unit that provides a means for controlling the sensor. The computer processing unit also provides a means for the fluid monitoring unit to transmit and receive data.
[0054] Preferably the computer processing unit generates an output signal if the pressure differential of the fluid supply across the filter is outside of a predetermined tolerance value.
[0055] The computer processing unit may also generate an output signal if the water content within the fluid supply is outside of a predetermined tolerance value.
[0056] The computer processing unit may also generate an output signal if a density or mass of the particulate or debris content within the fluid supply is outside a predetermined tolerance value.
[0057] The computer processing unit may also generate an output signal if the quality or purity of the chemical composition of the fluid supply is outside a predetermined tolerance value.
[0058] According to a fourth aspect of the present invention there is provided a fluid monitoring unit for monitoring a fluid supply to a fluid umbilical, the fluid monitoring unit comprising a monitoring zone and a sensor, the sensor providing a means for detecting the occurrence of one or more events within the monitoring zone detrimental to the flow of the fluid supply through the fluid umbilical, wherein the monitoring zone is configured to provide upstream fluid cooperation with an entrance of the fluid umbilical.
[0059] Embodiments of the fourth aspect of the invention may comprise preferred and optional features of the third aspect of the invention and vice versa.
[0060] According to a fifth aspect of the present invention there is provided a hydrocarbon exploration and production installation, the installation comprising at least one supply conduit that provides a means for fluid communication between a fluid source and a fluid conduit, and a fluid monitoring unit in accordance with the third aspect of the present invention, wherein the fluid monitoring unit is located within the supply conduit upstream of the fluid conduit.
[0061] Preferably the installation further comprises a pump located between the fluid source and the fluid monitoring unit.
[0062] Optionally the installation further comprises a shut off valve located between the fluid monitoring unit and the fluid conduit.
[0063] Preferably an output signal from the fluid monitoring unit is employed as a feedback signal to activate a shut down of the pump. The output signal may also be employed as a feedback signal to activate closure of the shut off valve.
[0064] Preferably the installation further comprises an operations control module connected to the fluid monitoring unit so as to provide a means for monitoring and recording output data from the fluid monitoring unit.
[0065] According to a sixth aspect of the present invention there is provided a hydrocarbon exploration and production installation, the installation comprising at least one supply conduit that provides a means for fluid communication between a fluid source and a fluid umbilical, and a fluid monitoring unit in accordance with the fourth aspect of the present invention, wherein the fluid monitoring unit is located within the supply conduit upstream of the fluid umbilical.
[0066] Embodiments of the sixth aspect of the invention may comprise preferred and optional features of the third fourth and fifth aspects of the invention and vice versa.
BRIEF DESCRIPTION OF DRAWINGS
[0067] Aspects and advantages of the present invention will become apparent upon reading the following detailed description of example embodiments and upon reference to the following drawings in which:
[0068] FIG. 1 presents a schematic diagram of a surface production facility, that provides fluid communication with an umbilical, and which incorporates fluid monitoring units in accordance with an embodiment of the present invention; and
[0069] FIG. 2 presents a schematic diagram of the fluid monitoring units of FIG. 1 .
[0070] In the description which follows, like parts are marked throughout the specification and drawings with the same reference numerals. The drawings are not necessarily to scale and the proportions of certain parts have been exaggerated to better illustrate details and features of embodiments of the invention.
DETAILED DESCRIPTION
[0071] In order to provide understanding of the various aspects of the present invention a schematic diagram of a surface production facility, generally depicted by the reference numeral 1 , is presented in FIG. 1 , while FIG. 2 presents a schematic diagram of a fluid monitoring unit 2 employed with the surface production facility 1 .
[0072] The surface production facility 1 can be seen to comprise four supply conduits 3 that provide a means for fluid communication between a corresponding fluid source 4 and an umbilical 5 via a topside umbilical termination unit (TUTU) 6 . In the presently described embodiment the fluid sources comprise a corrosion inhibitor 4 a (one such suitable corrosion inhibitor being that sold by Champion Technologies under the trade mark Scortron® G10000), a scale inhibitor 4 b (one such suitable scale inhibitor being that sold by Champion Technologies under the trade mark Gyptron® SA110N), methanol 4 c and a wax inhibitor 4 d (one such suitable wax inhibitor being that sold by Champion Technologies under the trade mark Flexoil® WM1840).
[0073] Within each supply conduit 3 is located a metering pump 7 , a fluid monitoring unit 2 and a shut-off valve 8 . Each metering pump 7 is employed to regulate the pressure flow of the fluid within its respective supply conduit 3 and hence into an internal tube of the umbilical 5 . The fluid monitoring units 2 are located between the metering pumps 7 and the TUTU 6 and are employed to monitor one or more parameters associated with the transported fluid before it is pumped into the umbilical 5 . A feedback connection 9 provides a means for the fluid monitoring unit 2 to stop its respective metering pump 7 and/or to close the respective shut-off valve 8 when the occurrence of a detrimental effect for the fluid flow within the umbilical 5 is detected e.g. a potential blockage forming scenario is detected or significant levels of corrosion are detected, further details of which are provided below.
[0074] An electricity supply 10 provides a dedicated power source for each of the fluid monitoring units 2 . Each fluid monitoring unit 2 is also connected to an operations control module 11 which may be located within the surface production facility 1 . Optionally, the operations control module 11 is connected to a remote operations control module 12 that provides a means for remotely monitoring and controlling the fluid supplies into the umbilical 5 . Communication to and from the facility and within the facility itself may be by RS232, Ethernet or wireless means.
[0075] From FIG. 2 each fluid monitoring unit 2 can be seen to comprise a monitoring zone in the form of a conduit 13 through which the fluid supply is transmitted such that the monitoring zone provides a means for upstream fluid cooperation with an entrance of an internal tubing of the umbilical 5 . Located within the monitoring zone 13 is a filter 14 which provides an initial means for preventing particulates and other debris from entering the internal tubing of the umbilical 5 . The fluid monitoring unit 2 further comprises a pressure sensor 15 that provides a means for measuring the pressure differential of the fluid supply across the filter 14 or the absolute pressure of the fluid supply within the monitoring zone 13 (an Able Instrumentation Differential Pressure Gauge Model 126 being one such suitable pressure sensor), a thermometer 16 that provides a means for measuring the temperature of the fluid supply (an Able Instruments eight wire, one series temperature switch being one such suitable thermometer), and a hygrometer 17 that provides a means for measuring the water content within the fluid supply (an Able Instruments HTF dewpoint sensor being one such suitable hygrometer). Optionally, the fluid monitoring unit 2 further comprises a particulate or flocculation sensor 18 (an Able Instruments Model 980 series dual beam Photometer being one such suitable particulate sensor); a UV spectrometer 19 (an Able Instruments Model 960 UV-Analyzer being one such suitable UV spectrometer); and a flow meter 20 that provides a means for accurately monitoring the rate of flow of the fluid before it enters the internal tubing of the umbilical 5 . The flow meter may be a positive displacement flow meter, for example a helical screw flow meter or a rotary piston flow meter since both meter types provide accurate readings at relatively low flow rates.
[0076] Each of the sensors 15 , 16 , 17 , 18 , 19 and 20 are connected to a CPU 21 which provides a means for controlling the sensors 15 , 16 , 17 , 18 , 19 and 20 , processing the measured data and relaying the data on to the control modules 11 and/or 12 .
[0077] In the presently described embodiment the filter 14 comprises a two micron absolute filter, however the filter size may be changed depending on expected flow rates within the system. For the presently described surface production facility 1 the fluid supply flow rates range from a minimum flow rate of 40 ml/min to a maximum flow rate of 1000 ml/min. Corresponding pressures through the system range from 0 to 5000 psi.
[0078] It is preferable for the distance between the fluid monitoring unit 2 and the shut-off valve 8 to be sufficient that on the fluid monitoring unit 2 detecting the occurrence of a detrimental effect for the fluid flow within the umbilical the shut-off valve 8 can be closed before the fluid supply passes its physical location.
[0079] The above described fluid monitoring units 2 allow for various ways to detect the occurrence of solidification within supplied fluids and for analysing the quality of supplied fluids. The onset of solidification within the fluid supply can be indicative of coagulation or flocculation caused by chemical reactions between different fluids or the use of low quality or purity fluids, and/or the formation of solid particulates or debris as a result of corrosion within the umbilical itself. The various techniques will now be described in further detail.
Monitoring Pressure Deferential
[0080] The first method employs the pressure sensor 15 to monitor a pressure differential across the filter 14 . The pressure differential is correlated with the temperature of the fluid, as measured by the thermometer 16 . This correlation may take place directly within the pressure sensor 15 , the CPU 21 or more preferably within the control modules 11 or 12 . A change in the viscosity within the fluid supply is detected as a corresponding change in the pressure differential across the filter 14 . If the change in pressure differential is outside of a predetermined tolerance value for that particular fluid, and does not correlate with a corresponding temperature change, as detected by the thermometer 16 , then this is indicative of a chemical reaction causing coagulation or flocculation, for example the inadvertent mixing of a scale inhibitor and methanol. Coagulation or flocculation can lead to the onset of a blockage within the umbilical 5 and so in such circumstances the fluid monitoring unit 2 would activate an alarm within the control module 11 and/or 12 and preferably provide for the automatic shut down of the metering pump 7 in conjunction with the closing of the corresponding shut-off valve 8 . This would allow the operator to check the facility 1 to see if a non-compatible chemical combination had been set up in error sufficiently early in the process so as to avoid the occurrence of a costly blockage.
Monitoring Water Content
[0081] The second method for detecting potential on set of a blockage is achieved via the employment of the hygrometer 17 . The hygrometer 17 is set to detect the presence of water within the fluid supply between 0% and 100% using a small electrical current. A predetermined value, with acceptable tolerance levels, is provided for a particular fluid supply. Activation of the alarms and/or the shutting down of the fluid supply, as previously described, again results if the detected water level moves out with the predetermined tolerance levels. For example, the water content for a water-based fluid supply e.g. a biocide may be of the order of 80% with an accepted tolerance level of ±0.5%. If a solvent, for example a wax inhibitor, were to be introduced to the water-based fluid supply then the water content may fall to around 78% thus triggering the alarms and/or the shutting down of the supply line. Alternatively, the water content for a solvent-based fluid supply e.g. an ashphaltene inhibitor may be of the order of 0% with an accepted tolerance level of +0.5%. If a water based fluid, for example an H 2 S scavenger or even simply rain water were to be introduced to the solvent-based fluid supply then the water content may rise to above 0.5% thus triggering the alarms and/or the shutting down of the supply line.
[0082] What is important for the operation of the above solidification diagnostic is the establishment of a base water level content for a fluid supply and an appropriate tolerance level. The hygrometer 17 then allows for changes in the water content of the fluid supply to be monitored and appropriate action taken if this exceeds the predetermined tolerance value.
[0083] It is preferable for the fluid monitoring unit 2 to also be capable of measuring and recording the absolute pressure, temperature and rate of fluid flow of the fluid supply. The pressure sensor 15 , the thermometer 16 and the flow meter 20 in conjunction with the control modules 11 and/or 12 can facilitate all of these diagnostics.
Particle Analysis
[0084] The employment of the particulate sensor 18 provides a means for detecting the presence of particulates or debris with the fluid supply. The particulates or debris may be of a type that is transmitted directly into the monitoring zone 13 or are formed as a result of a chemical reaction within the monitoring zone 13 e.g. via corrosion.
[0085] The particulate sensor 18 preferably comprises an optical sensor whereby one or more light sources and a photodetector are arranged to provide sensing points within the monitoring zone 13 e.g. an Able Instruments Model 980 series dual beam Photometer. Particulates or debris passing through sensing points then acts to scatter the light from the light source onto the photodetector which is thereafter transformed into a pulsed signal. The number of pulses per unit time is proportional to the density of particulates or debris presents. The pulse signal is then converted into a voltage output for relaying to the control modules 11 and/or 12 .
[0086] Alternatively, or in addition to the optical particulate sensor, the particulate sensor 18 may comprise a type that employs a combination of passive-induction and protected-probe technologies (a Baumer Process Instrumentation conductivity sensor ISL05x being one such suitable sensor). As particles or debris flow near and around the probe, minute currents are dynamically induced within the probe. These currents can then be processed to provide an absolute output that is substantially linear to the mass of the particulates or debris present.
[0087] Optical particulate sensors are preferable for use with oil based fluids or solvents e.g. wax inhibitor while they are less effective when used with water based fluids e.g. biocides. In such fluids it is preferable to employ the passive induction type of sensors.
[0088] In a similar manner to that described above a predetermined particulate or debris level is defined for a particular fluid supply. If the mass of the particulate or debris exceeds this predetermined value then the fluid monitoring unit 2 activates the corresponding alarms and/or shuts down the fluid supply.
[0089] As well as the fluid monitoring units 2 being configured to operate or trigger an alarm and/or shut down the fluid supply upon exceeding one or more predetermined parameters, the control modules 11 or 12 may also be configured to automatically e-mail an appropriate preselected person about the potential problem within the facility 1 . This facility has particular application in the following circumstances.
UV Spectroscopy
[0090] During the operation of the surface production facility 1 there are times when it is required to be shut down. On occasion this shut down period may last several weeks. On restarting the surface production facility 1 it can be found to have developed a blockage even although no obvious contamination of the fluid has occurred.
[0091] It has been recognised by the inventors that the source of the formation of such blockages lie within the inherent quality or purity of the fluid being transported i.e. if the fluid quality or purity is below a predetermined value and then the fluid is allowed to remain static within the umbilical then a blockage may form.
[0092] The employment of the UV spectrometer 19 provides a means for analysing the chemical composition of a fluid within the monitoring zone 13 and thus provide an indication if it falls below a predefined quality or purity level. In such circumstances the fluid monitoring unit 2 notifies the control modules 11 and/or 12 that the fluid should not be allowed to remain static within the umbilical 5 .
[0093] If a shut down event of the surface production facility 1 occurs during this period then subsequent periodic reminders may be sent to the operator of the surface production facility 1 notifying them that unless pumping of the fluid is re started then they are heading for the occurrence of a blockage within the umbilical 5 .
[0094] The above described method and apparatus provide a means for protecting the integrity of a fluid conduit and in particular a fluid umbilical. The method and apparatus allow for a reduction in the vulnerability of these expensive assets due to human error by providing a means for continuous dynamic monitoring of the injected fluid supplies and providing for automated pump shut down when potential detrimental effects for the fluid flow within the fluid umbilical are detected e.g. blockage forming circumstances. Significantly, the fluid monitoring units provide a proactive method that prevents the formation of blockages rather than allowing for a reactive method to be employed in response to the detection of a blockage, as is the case for known prior art systems.
[0095] By performing real time particle analysis and monitoring chemical compatibilities, via pressure, temperature, water and particle content measurements, and UV spectroscopy round the clock analysis can be performed. This allows for trends within the facility to be built up for individual umbilicals, or other fluid conduits, and so enables the activation of alarms or automated shut downs, as and when appropriate.
[0096] The adapted facility also allows for periodic integrity reviews to be carried out wherein information regarding fluid cleanliness (NAS rating), viscosity, water content, differential pressure, absolute pressure, temperature and flow rates can be displayed in real time or downloaded for historical data reviews.
[0097] The foregoing description of the invention has been presented for purposes of illustration and description and is not intended to be exhaustive or to limit the invention to the precise form disclosed. The described embodiments were chosen and described in order to best explain the principles of the invention and its practical application to thereby enable others skilled in the art to best utilise the invention in various embodiments and with various modifications as are suited to the particular use contemplated. Therefore, further modifications or improvements may be incorporated without departing from the scope of the invention as defined by the appended claims. | A method and apparatus for monitoring a fluid that is to be transported through a fluid conduit within a hydrocarbon exploration and production installation is described. A monitoring zone is established upstream of the fluid conduit configured such the fluid supply to the fluid conduit is introduced via the monitoring zone. The fluid supply within the monitoring zone is monitored for the occurrence of events detrimental to the flow of the fluid supply through the fluid conduit. Monitoring the fluid supply prior to entering the fluid conduit allows for the early detection of an event detrimental to the flow of the fluid supply e.g. a chemical reaction indicative of corrosion of the fluid conduit or the formation of a potential blockage within the fluid conduit. In this way the risk of costly blockages or structural failure occurring within the fluid conduit is reduced. | 8 |
BACKGROUND OF THE INVENTION AND RELATED ART STATEMENT
The present invention relates to a method for welding together electrically conductive members with an electrically insulating member therebetween.
In a conventional method for welding together the electrically conductive members with the electrically insulating member therebetween, an electric current value for energizing electrically the electrically conductive members to be welded together, a timing and period for applying the electric current to the electrically conductive members and a force for pressing the electrically conductive members against each other and compressing the electrically insulating member therebetween are fixed constantly or not adjusted in a welding process.
OBJECT AND SUMMARY OF THE INVENTION
An object of the present invention is to provide a method for welding together electrically conductive members with an electrically insulating member therebetween, by which method the electrically insulating member can be removed securely therebetween, and a heat energy for welding together the electrically conductive members can be kept at an appropriate degree.
According to the present invention, a method for welding together electrically conductive members, comprises
detecting step for detecting a removal of an electrically insulating member between a first electrically conductive member and a second electrically conductive member, and
welding step for welding together the first electrically conductive member and the second electrically conductive member by an electricity through them to be fixed to each other, after the removal of the electrically insulating member therebetween is detected.
In the present invention, since the first electrically conductive member and the second electrically conductive member are welded together by the electricity through them to be fixed to each other after the removal of the electrically insulating member therebetween is detected, the electrically insulating member does not remain therebetween after the first electrically conductive member and the second electrically conductive member are welded together, and an electric conductivity between first electrically conductive member and the second electrically conductive member is sufficient for an appropriate welding electric current so that the heat energy for welding together the electrically conductive members is supplied to them securely and the first electrically conductive member and the second electrically conductive member are securely welded together. Further, since the removal of the electrically insulating member is detected between the first and second electrically conductive members, a positional relation therebetween may be substantially constant in both of the detecting and welding steps, or a contact therebetween through the electrically insulating member may be kept in both of the detecting and welding steps.
The removal of the electrically insulating member may be detected from in increase (including a start of increase) in temperature of at least one of the first and second electrically conductive members, because the temperature of at least one of the first and second electrically conductive members is increased by an ohmic resistance heating through the first and second electrically conductive members when the electrically insulating member is removed at least partially by a heat energy and/or compressing force applied thereto from at least one of the first and second electrically conductive members so that a direct contact or substantial electric conduction between the first and second electrically conductive members is generated, or because the electrically insulating member is made easily movable or removed by the increase in temperature of at least one of the first and second electrically conductive members when the electrically insulating member is thermoelastic or thermovaporizable. The increase in temperature may be measured from an increase in electric resistance (including a start of increase thereof) through the first and second electrically conductive members, or alternatively, the increase in temperature may be measured from a temperature of a surface of the at least one of the first and second electrically conductive members through a surface temperature sensor. The increase in temperature may be a difference between a certain temperature and am actual temperature or an increase to an absolute temperature.
The removal of the electrically insulating member may be detected from an decrease (including a start of decrease) in electric resistance through the first and second electrically conductive members, because the electric resistance through the first and second electrically conductive members is decreased by the removal of the electrically insulating member or by the direct contact between the first and second electrically conductive members. The decrease in electric resistance may be a difference between a certain electric resistance and an actual electric resistance, or a decrease to an absolute electric resistance.
The removal of the electrically insulating member may be detected from an evaporative gas from the electrically insulating member which is heated in the detecting step, because the electrically insulating member is elastic or easily movable to be removed between the first and Second electrically conductive members when the electrically insulating member is vaporized, or because the removal of the electrically insulating member is performed by a vaporization thereof.
The removal of the electrically insulating member may be performed by a force compressing the electrically insulating member between the first and second electrically conductive members or a heat energy applied to the electrically insulating member.
The removal of the electrically insulating member may be detected from a temperature of at least one of the first and second electrically conductive members more than a predetermined temperature sufficient for making the electrically insulating member soft or movable for being removed between the first and second electrically conductive members. The temperature thereof is measured from a value of electric resistance through the first and second electrically conductive members, because the higher the temperature of the first and second electrically conductive members is, the larger the value of electric resistance therethrough is. The temperature thereof is measured from the temperature of the surface of the at least one of the first and Second electrically conductive members through the surface temperature sensor.
The removal of the electrically insulating member may be detected from an electric resistance value through the first and second electrically conductive members less than a predetermined value, because the electric resistance value decreases to less than the predetermined value when the electrically insulating member is removed at least partially or the first and second electrically conductive members contact directly with each other at least partially to form an electrical conduction therebetween.
The removal of the electrically insulating member may be detected from a direct contact (including a start of direct contact) between the first and second electrically conductive members, the direct contact may be detected from an increase in temperature of at least one of the first and second electrically conductive members energized to be heated by an electricity made flow through them by the direct contact, or may be detected from an decrease in electric resistance through the first and second electrically conductive members, which decrease is caused by the direct contact.
The removal of the electrically insulating member may detected from a direct contact area between the first and second electrically conductive members more than a predetermined area causing an electrical conduction therebetween sufficient for allowing a sufficient welding electric current. The direct contact area more than the predetermined area may detected from an decrease in electric resistance value through the first and second electrically conductive members more than a predetermined value, a difference between an actual electric resistance value and a certain actual electric resistance value or to a decrease to an absolute electric resistance value.
In the detecting step, at least one of the first and second electrically conductive members may be electrically energized to generate a heat energy for heating the electrically insulating member before the removal of the electrically insulating member is detected, or alternatively, both of the first and second electrically conductive members may be prevented by the electrically insulating member from being electrically energized and the electrically insulating member is compressed between the first and second electrically conductive members, before the removal of the electrically insulating member is detected.
The removal of the electrically insulating member may be detected from a time which is more than a predetermined time and in which a temperature of at least one of the first and second electrically conductive members more than a predetermined temperature sufficient for removing the electrically insulating member is kept.
The removal of the electrically insulating member is detected from a time which is more than a predetermined time and in which a decrease in electric resistance value through the first and second electrically conductive members more than a predetermined degree allowing an electric current sufficient for welding is kept.
The electrically insulating member may be thermoelastic or thermoplastic for being removed between the first and second electrically conductive members when at least one of the first and second electrically conductive members is heated. An evaporative gas may be generated from the electrically insulating member when the electrically insulating member is heated at more than a predetermined temperature or melting or vaporizing temperature thereof. An electric resistance of each of the first and second electrically conductive members may increase according to an increase in temperature thereof.
A force for compressing the electrically insulating member between the first electrically conductive member which is prevented by the electrically insulating member from being energized electrically in the detecting step and the second electrically conductive member which is energized electrically in the detecting step may be decreased after the removal of the electrically insulating member is detected. A force for compressing the electrically insulating member between the first and second electrically conductive members both of which are prevented by the electrically insulating member from being energized electrically during the detecting step may be increased after the removal of the electrically insulating member is detected.
An electrical energizing of at least one of the first and second electrically conductive members may be weakened and/or stopped temporarily between the detecting step and the welding step.
The removal of the electrically insulating member may be detected from an increase in temperature of at least one of the first and second electrically conductive members in comparison with the substantially minimum temperature thereof in the detecting step. The removal of the electrically insulating member may be detected from a decrease in electric resistance through the first and second electrically conductive members in comparison with the substantially maximum electric resistance therethrough in the detecting step. The removal of the electrically insulating member may be detected from an increase in electric resistance value through the first and second electrically conductive members in comparison with the substantially minimum electric resistance value therethrough in the detecting step. The removal of the electrically insulating member may be detected from an increase in direct contact area between the first and second electrically conductive members in comparison with the detected substantially minimum direct contact area therebetween in the detecting step.
The welding step may be finished when a width (W in FIGS. 1 and 6) through the first and second electrically conductive members is decreased to a predetermined or desirable width. The welding step may be finished when a width (W in FIGS. 1 and 6) through the first and second electrically conductive members is decreased by a predetermined degree relative to a width therethrough measured when a start of direct contact between the first and second electrically conductive members is detected. The welding step may be finished when a predetermined heat energy value is applied t# the first and second electrically conductive members to be welded together.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a whole schematic block diagram showing a first embodiment of the present invention;
FIG. 2 is a time chart illustrating an inter-electrode resistance R, an electrode displacement quantity X, a welding pressure P and a welding current I;
FIG. 3 is an explanatory diagram for explaining a coating exfoliation start timing with a variation in the inter-electrode resistance R;
FIG. 4 is a graphic chart showing a relationship between a coating exfoliating rate and a rising resistance RU;
FIG. 5 is an explanatory diagram for comparing a section of a welding part, a welding strength and a deterioration in welding in the first embodiment described above with those in the prior art;
FIG. 6 is a whole schematic block diagram showing a second embodiment of the present invention;
FIG. 7 is a time chart showing variations in the inter-electrode resistance R, the welding pressure P, the welding current I and a main current Im;
FIG. 8 is a graphic chart showing a relationship between a coating exfoliated area S and a falling resistance RL;
FIG. 9 is a graphic chart showing a relationship between a joining part area and an welding energy;
FIG. 10 is a graphic chart showing a relationship between a welding part hardness, i.e., a welding strength and a welding time;
FIG. 11 is a block circuit diagram illustrating the principal portion of a third embodiment of the present invention;
FIG. 12 is a flowchart showing a first part of actions of a microcomputer in FIG. 11;
FIG. 13 is a flowchart sowing a middle part thereof;
FIG. 14 is a flowchart showing a last part thereof;
FIG. 15 is a block circuit diagram showing the principal portion of a fourth embodiment of the present invention;
FIG. 16 is a flowchart showing a first part of the actions of the microcomputer in FIG. 15;
FIG. 17 is a flowchart showing a middle part thereof; and
FIG. 18 is a flowchart showing a last part thereof.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
A first embodiment of the present invention will hereinafter be described with reference to the drawings. FIG. 1 illustrates an example where the present invention is applied to a double electrode type resistance welding machine M. This double electrode type resistance welding machine M includes an upper electrode 10 and a lower electrode 20 (both are composed of tungsten, etc.) that are disposed in up-and-down relationship to confront each other. The upper electrode 10 has its pressurizing surface 11. The pressurizing surface 11 depresses a welded material 30 consisting of a terminal 30a mounted on a mounting surface 21 of the lower electrode 20 and a coated wire 30b. Resistance welding is applied to the welded material 30 in accordance with a welding current flowing from the upper electrode 10 across the welded material 30 to the lower electrode 20. The terminal 30a of the welded material 30 is composed of a material such as a cooper alloy or cooper. A tip part 31 of this terminal 30a is bent in a U-shape as a bent part. Further, the coated wire 30b is formed by coating a wire 32 annularly with a coating 33 consisting of a thermoplastic and/or thermally vaporizable insulating material such as polyester, etc. A tip part of this coated wire 30b undergoes the resistance welding and is, as illustrated in FIG. 1, orthogonally inserted into the U-shaped bent part 31 of the terminal 30a.
Next, a control unit E for the resistance welding by the resistance welding machine M will be explained. This control unit E includes an, air cylinder 40 and a proportional control valve 50. The air cylinder 40 moves down the upper electrode 10 in accordance with an air flow pressure-fed via the proportional control valve 50 from a pneumatic source 50a. A welding pressure is thereby applied to the bent part 31 of the terminal 30a from above in the FIG. 1. The proportional control valve 50 controls a quantity of the air flow pressure-fed to the air cylinder 40 from the pneumatic source 50a. This control is effected in accordance with a valve opening based on the proportional control by a welding pressure control circuit 150 which will be mentioned later. A welding power supply 60 is connected via power supply supply conductors 61, 62 to the upper electrode 10 and the lower electrode 20 as well. This welding power supply 60 flows a sine wave welding current at 60 (Hz) through the power supply conductor 61, the upper electrode 10, the welded material 30 and the lower electrode 20. In such a case, the welding power supply 60 includes a relay 60a consisting of a relay coil Ry and a normally open relay switch Y. This relay 60a acts to output the welding current from the welding power supply 60 on closing the relay switch Y due to an excitation of the relay coil Ry on one hand. The relay 60a acts to stop outputting the welding current from the welding power supply 60 on opening the relay switch Y due to a demagnetization of the relay coil Ry on the other hand.
A welding current detection circuit 70 is constructed of a current detection coil 71 and a current detection unit 72. The current detection coil 71 detects a welding current (hereinafter called a welding current I) flowing through the power supply conductor 62. The current detection coil 71 thereby generates a differential detection signal having a differential waveform of the welding current I. The current detection unit 72 is composed of an integration circuit and an amplifier. This current detection unit 72 causes the integration circuit to integrate the differential detection signal from the current detection coil 71. A result of this integration is amplified by the amplifier and outputted as a detected welding current. A voltage detection circuit 80 detects and amplifies an inter-electrode voltage (hereafter referred to as an inter-electrode voltage V) generated between the upper electrode 10 and the lower electrode 20. The voltage detection circuit 80 then generates the voltage as an inter-electrode detected voltage. A displacement quantity detection circuit 90 includes a differential transformer 91 and an electrode displacement quantity detection unit 92 having an amplifier. The differential transformer 91 is connected via its arm 91a to the upper electrode 10. While on the other hand, this displacement quantity detection circuit 90 causes the differential transformer 981 to detect a down-shift quantity of the arm 91a which corresponds to a down-shift quantity of the upper electrode 10 from an up-shift end. This down-shift quantity is amplified and outputted as an electrode displacement quantity (hereafter called an electrode displacement quantity X) by means of the displacement quantity detection unit 92.
An arithmetic processing circuit 100 effects, when actuated, an arithmetic process to increase a welding pressure P on the welded material 30 up to a value required for exfoliating the coating of the coated wire 30b. With an end of stepping up the welding pressure P, the arithmetic processing circuit 100 performs the arithmetic needed for outputting the welding current I from the welding power supply 60. Thereafter, the arithmetic processing circuit 100 computes effective current and voltage values IRMS, VRMS thereof on the basis of the detected welding current given from the welding current detection circuit 70 and the inter-electrode voltage given from the voltage detection circuit 80 per sampling timing cycle. Based on the two effective values IRMS, VRMS, the circuit 100 computes an inter-electrode resistance R (=VRMS/IRMS) between the upper electrode 10 and the lower electrode 20. Simultaneously, the circuit 100 compares two continuous inter-electrode resistances among the inter-electrode resistances R. The circuit 100 sequentially selects the smaller of the two electrode resistances thus compared. Selected further is the electrode displacement quantity X from the displacement quantity detection circuit 90 that corresponds to each selected inter-electrode resistance R.
Further, upon reaching the minimum value of the latest or last-measured or most-newly measured selected inter-electrode resistance R, the arithmetic processing circuit 100 determines the same latest selected inter-electrode resistance R as a minimum resistance Rmin. Besides, the latest electrode displacement quantity X corresponding to the minimum resistance Rmin is determined as a minimum displacement quantity Xmim. Thereafter, the circuit 100 computes a rising resistance RU from the minimum resistance Rmin per sampling timing cycle on the basis of the inter-electrode resistance R. The circuit re-computes the electrode displacement quantity X given afterward from the displacement quantity detection circuit 90 as an electrode displacement quantity X on the basis of the minimum displacement quantity Xmin. A rising resistance setting circuit 110 sets a rising resistance RUO which will be mentioned later. An electrode displacement quantity setting circuit 120 sets an electrode displacement quantity Xo which will hereafter be stated.
By the way, the following is a reason why concepts of the inter-electrode resistance R, the electrode displacement quantity X, the minimum resistance Rmin and each rising resistance RU are, as described above, introduced into the arithmetic operation by the arithmetic processing circuit 100. There will be also elucidated a reason why concepts of the set rising resistance RUO set by the rising resistance setting circuit 110 and the set electrode displacement quantity Xo set by the electrode displacement quantity setting circuit 120 are introduced into the arithmetic operation. The present inventors repeatedly performed a variety of tests about the resistance welding between the coated wire and the terminal. The inventors proved that when the following resistance welding is to be conducted, a reliability on the resistance welding quantity can be remarkably improved by obviating the drawbacks described above. To start with, the inventors examined how the resistance (i.e., the inter-electrode resistance R) between the upper and lower electrodes varies in the course of the resistance welding when a good resistance welding quality between the coated wire and the terminal is obtained. This inter-electrode resistance R turned out to exhibit a concave-like variation tendency as shown in the left half of a characteristic curve La in FIG. 2 as well as in FIG. 3. This resistance R also turned out to have the minimum resistance Rmin. In such a case, the fact that the inter-electrode resistance R increases after reaching the minimum resistance value Rmin is derived from the following reason. The minimum resistance value decreases as the coating exfoliation proceeds and the contact area between the upper electrode and the terminal increases with a progression of pressurization after being energized with electricity. The decrease in the inter-electrode resistance R down to the minimum resistance value Rmin is accompanied by increments both in the energizing current and in temperatures of the two electrodes 10, 20. This leads to a rise in each internal resistance of the two electrodes 10, 20. The inter-electrode resistance R rises from the minimum resistance value Rmin. This is the reason why the inter-electrode resistance R increases after reaching the minimum resistance Rmin.
Further, when the inter-electrode resistance R takes the minimum resistance Rmin, as illustrated in FIG. 3, a degree of conduction between the upper and lower electrodes abruptly rises. Known was the fact that not the welding but a complete coating exfoliation of the coated wire (the direct contact or complete electrical contact of the wire and the terminal) tarts when R=Rmin. It was also known therefrom that the coating exfoliating process can be separated from the welding process in the resistance welding. Further, the degree of increment in the inter-electrode resistance R after being decreased down to the minimum resistance Rmin is expressed by the rising resistance RU as indicated by the characteristic curve La in FIG. 2. In this case, it proved that the rising resistance RU has a close correlativity to a coating exfoliation rate of the coated wire as shown in FIG. 4. It is also known from the above-mentioned that if the welding current continues to flow till the rising resistance TRU increases up to the preset value RUO (a value enough to secure a necessary coating exfoliation rate), the coating exfoliated state of the coated wire can be always stably kept with no unevenness. Such a phenomenon is similarly obtained by controlling a quantity of input heat (square of welding current×inter-electrode resistance×time) from the time when the inter-electrode resistance R reaches the minimum resistance Rmin.
Further, a degree of collapse of the coated wire is set proper, thereby improving a joint efficiency and securing a stable welding strength in the welding process. For this purpose, a relationship between the degree of collapse of the coated wire and the joint efficiency was examined in many ways through tests. After the rising resistance RU has reached the above-described set rising resistance value RUO, a conduction of the welding current temporarily halts for a cooling or temperature-keeping period. A resistance exothermic quantity is increased with an enhancement of the contact resistance between the two electrodes and the welded material by controlling the welding pressure (i.e., welding pressure P) on the terminal and the coated wire through the upper electrode down to a pressure as indicated by the characteristic curve Lc in FIG. 2. The resistance welding is promoted while reducing the degree of collapse of the coated wire. Besides, when R=Rmin is established with a start of the coating exfoliation, the corresponding downward-displacement quantity of the upper electrode reaches the preset electrode displacement quantity Xo (see a characteristic curve Lb in FIG. 2) of the upper electrode. It was known that if the conduction of the welding current is ended off at this time, it is possible to improve the joint efficiency and obtain the stable welding strength.
A comparative judging circuit 130 gives, when actuated, a welding pressure control circuit 150 a command to augment the opening of the proportional control valve 50 up to a value of the welding pressure P enough to exfoliate the coating of the coated wire 30b. Thereafter, the circuit 130 commands the current control circuit 140 to output the welding current I from the welding power supply 60. Further, the comparative judging circuit 130 compares each rising resistance RU given from the arithmetic processing circuit 100 with the rising resistance RUO given from the rising resistance setting circuit 110. When RU=RUO is established, the circuit 130 makes such judgments that there are necessities to temporarily halt the conduction of the welding current I and to lower the welding pressure P on the welded material 30. In addition, the comparative judging circuit 130 commands the current control circuit 140 to resume the conduction of the welding current I with a stability of the welding pressure P after a predetermined time (preset from the test) has elapsed in connection with reducing of the welding pressure P through the arithmetic processing circuit 100. The electrode displacement quantity X given from the arithmetic processing circuit 100 is compared with the set electrode displacement quantity Xo given from the displacement quantity setting circuit 120. When X=Xo is established, the comparative judging circuit 130 makes judgments to finish both the conduction of the welding current I and the pressurization on the welded material 30.
The current control circuit 140 controls the welding power supply 60. This control is effected to output the welding current I from the welding power supply 60, temporarily stop the output of the welding current I, resume the output of the welding current I and end off the output of the welding current I. These actions are performed in response to the command for the conduction of the welding current I, the judgment to temporarily halt the conduction thereof, the judgment to resume the conduction and the judgment to end off the conduction. Further, the welding pressure control circuit 150 controls the proportional control valve 50. this control is conducted so that the opening of the proportional control valve 50 is increased or decreased and made zero in response to the commands to increment and decrement the welding pressure P and the end command that are issued from the comparative judging circuit 130.
In accordance with the thus constructed first embodiment, it is assumed that the welded material 30 is, as illustrated in FIG. 1, mounted on the mounting surface 21 of the lower electrode 20 under the pressurizing surface 11 of the upper electrode 10 of the resistance welding machine M. In this instance, it is also presumed that both the welding pressure P on the welded material 30 and the welding current from the welding current power supply 60 are zero. On the occasion of the resistance welding on the welded material 30, however, if the control unit E is brought into an active state when the time t=t0 in FIG. 2, the arithmetic processing circuit 100 effects the arithmetic to increase the welding pressure P to a value enough to peel off the coating of the coated wire 30b. With this action, the comparative judging circuit 130 outputs, to the welding pressure control circuit 150, a command needed for setting the opening of the proportional control valve 50 to a value corresponding to the coating exfoliation value of the welding pressure P. Consequently, the welding pressure control circuit 150 controls the opening of he proportional control valve 50. The air flow from the pneumatic source 50a is thereby pressure-fed to the air cylinder 40. Besides, this air cylinder 40 moves down the upper electrode 10 in accordance with the air flow from the proportional control valve 50, thereby starting an operation to apply the welding pressure P as a value enough to peel off the coating on the welded material 30. At this moment, the displacement quantity detection circuit 90 detects and outputs the electrode displacement quantity X (see t=t0 in FIG. 2) of the upper electrode 10.
Subsequently, when the time t=t1 in FIG. 2 with the increase in the welding pressure P, the arithmetic processing circuit 100 executes an arithmetic operation required for outputting the welding current I from the welding power supply 60. With this operation, the comparative judging circuit 130 outputs, to the current control circuit 140, a command to output the welding current I from the welding power supply 60. For this purpose, the relay 60a closes the relay switch Y when excited by the relay coil Ry thereof under the control of the current control circuit 140. In response to this action, the welding power supply 60 starts the conduction of the welding current I through the power supply conductor 61, the upper electrode 10, the welded material 30, the lower electrode 20 and the power supply conductor 62 (see the symbol Ld in FIG. 2). At this time, the welding current I is detected by the welding current detection circuit 70 (see FIG. 2). The inter-electrode voltage V between the upper electrode 10 and the lower electrode 20 is at the same time detected by the voltage detection circuit 80.
After effecting the above-mentioned output arithmetic process of the welding current I, the arithmetic processing circuit 100 computes the effective values IRMS, VRMS thereof on the basis of the detected welding current given from the welding current detection circuit 70 and the inter-electrode voltage given from the voltage detection circuit 80 per sampling timing cycle. Based on the two effective values IRMS, VRMS, the circuit 100 computes an inter-electrode resistance R between the upper electrode 10 and the lower electrode 20. Simultaneously, the circuit 100 compares two continuous inter-electrode resistances R among the inter-electrode resistances R. The circuit 100 sequentially selects the smaller of the two electrode resistances thus compared. Selected further is the electrode displacement quantity X from the displacement quantity detection circuit 90 that corresponds to each selected inter-electrode resistance R. In such a case, as shown in FIG. 2, both of the electrode displacement quantity X and the inter-electrode resistance R start decreasing from the time when t=t1. This implies a start of the exfoliation of the coating 33 of the coated wire 30a.
During such a process, when t=t2 as shown in FIG, 2, the latest selected inter-electrode resistance R coincides with a selected inter-electrode resistance R just before it, thereby reaching the minimum value. Concomitantly, the arithmetic processing circuit 100 determines the same latest selected inter-electrode resistance R as a minimum resistance Rmin. Besides, the latest electrode displacement quantity X corresponding to the minimum resistance Rmin is determined as a minimum displacement quantity Xmin. Thereafter, the circuit 100 computes a rising resistance RU from the minimum resistance Rmin per sampling timing cycle on the basis of the inter-electrode resistance R. The circuit re-computes the electrode displacement quantity X given afterward from the displacement quantity detection circuit 90 as an electrode displacement quantity X on the basis of the minimum displacement quantity Xmin.
Thereafter, when the time t=t3 in FIG. 2, the latest rising resistance RU comes to a rising resistance RUO. Hereupon, the comparative judging circuit 130 judges that RU=RUO is established. The circuit 130 also make judgments that the conduction of the welding current I is required to be temporarily halted and that the welding pressure P on the welded material 30 is required to be reduced under the coating exfoliation value. Then, the current control circuit 140 controls the relay coil Ry of the relay 60a to be temporarily demagnetized in response to the judgment to temporarily halt the conduction of the welding current I which has been made by the comparative judging circuit 130. With this action, the relay 60a temporarily opens its relay switch Y, whereby the output of the welding current I from the welding power supply 60 is temporarily stopped. An increment in the inter-electrode resistance R is thereby temporarily halted (see t=t3˜t4 in FIG. 2). Besides, the welding pressure control circuit 150 controls the proportional control valve 50 to reduce its valve opening in response to the judgment to decrease the welding pressure P that has been given from the comparative judging circuit 130. Consequently, the quantity of the air flow pressure-fed to the air cylinder 40 from the proportional control valve 50 is reduced. The down-movement of the upper electrode 10 halts, and the reduction in the electrode displacement quantity X is also stopped. Besides, the welding pressure P on the welded material 30 decreases (see t=t3˜t4 in FIG. 2).
The reduction of the welding pressure P is completed when the time t=t4. After a predetermined time has passed, the welding pressure P is stabilized based on the latest detected displacement quantity X in the arithmetic processing circuit 100. Then, the comparative judging circuit 130 makes a judgment to resume the conduction of the welding current I. concomitantly, the current control circuit 140 controls to re-excite the relay coil Ry of the relay 60a. Therefore, the relay 60a closes the relay switch Y thereof. In response to this action, the conduction of the welding current I from the welding power supply 60 occurs again via the power supply conductor 61, the upper electrode 10, the welded material 30, the lower electrode 20 and the power supply conductor 62. This implies a shift to the welding process of the welded material 30 after the coating has been peeled off.
In this state, the welding between the terminal 30a and the tip part of the coat-exfoliated wire 32 from the coated wire 30b progresses under the foregoing stabilized condition where the welding pressure P is lowered. The inter-electrode resistance R in the arithmetic processing circuit 100 rectilinearly increases as shown in FIG. 2, whereas the electrode displacement quantity X rectilinearly decreases as shown in FIG. 2. Thereafter, when the time t=t5, the electrode displacement quantity X in the arithmetic processing circuit 100 reaches the set electrode displacement quantity Xo. Hereupon, the comparative judging circuit 130 judges that X=Xo is established in cooperation with the arithmetic processing circuit 100 and the electrode displacement quantity setting circuit 120 as well. The circuit 130 also makes a judgment to halt the conduction of the welding current I. At the same time, the circuit 130 make a judgment to stop the pressurization on the welded material 30. Subsequently, the relay coil Ry of the relay 60a is demagnetized to open the relay switch Y under the current control circuit 140 in response to the judgment to halt the conduction of the welding current I by the comparative judging circuit 130. The output of the welding current I from the welding power supply 60 is thereby ended off. Further, the proportional control valve 50 is controlled to close by the welding pressure control circuit 150 in response to the judgment to stop the pressurization that has been made by the comparative judging circuit 130. The pressure-feed of the air flow to the upper electrode 20 via the air cylinder 40 comes to an end. At this time, the inter-electrode resistance R is fixed (see FIG. 2). This implies that the pressure-feed of the air flow to the upper electrode 20 is finished when an inter-electrode electric energy becomes uniform.
As discussed above, in accordance with the first embodiment, the welding pressure P acts on the welded material 30 with a value enough to peel off the coating of the coated wire 30b in the coating exfoliating process. Simultaneously, the welded material 30 conducts the welding current I. This continues till the rising resistance RU increases up to the set rising resistance RUO after the inter-electrode resistance R has reached the minimum resistance Rmin. Then, the coating exfoliating process is ended off when RU=RUO is established, and the operation shifts to the welding process. The conduction of the welding current I temporarily halts, and simultaneously the welding pressure P is lowered. With the welding pressure P stabilized afterwards, the conduction of the welding current I is restarted. The welding process is finished when the electrode displacement quantity X reaches the set displacement quantity Xo. Hence, when the welded material 30 undergoes the resistance welding in the resistance welding machine M, this resistance welding control is conducted while being separated in terms of time into the coating exfoliating process and the resistance welding process. When establishing RU=RUO, the coating exfoliating process is completed. Hence, the stable coating-exfoliated state is attainable. Further, The tip part of the wire 33 is resistance-welded to the terminal 30a in the welding process under the lowered welding pressure P after the coating has been peeled off. This resistance welding is therefore attainable with a stabilized welding strength and a high joint efficiency without causing an excessive collapse of the wire 33. As a result, the resistance welding machine M is capable of securing the high quality resistance welding of the welded material 30 without causing deteriorations of the coating exfoliation and welding.
In this connection, there was performed a comparative test between the resistance welding quality in the first embodiment and that in the prior art. The result as shown in FIG. 5 was obtained. According to this result, it can be understood that the collapse of the wire according to this invention can be restrained more than in the prior art. It is because a sectional area of the welded part of the welded material 30 is increased by a factor of 1.2 as large as that in the prior art on the premise of confirmative conditions as shown in FIG. 5. Moreover, as illustrated in FIG. 5, a tensile strength increases more stably than in the prior art. It can be known that the welding strength (corresponding to a tensile shearing strength) in this invention increases more stably than in the prior art. Further, as shown in FIG. 5, it is also known that a fraction defective of welding due to deteriorations of the strength and the exfoliation in the present invention is reduced more remarkably than in the prior art.
Next a second embodiment of the present invention will be described with reference to the drawings. The second embodiment has the following constructive features. As shown in FIG. 6, a triple electrode type resistance welding machine Ma and a control unit Ea are adopted in place of the resistance welding machine M and the control unit E which have been explained in the first embodiment. A welded material 30A is resistance-welded in stead of the welded material 30. The resistance welding machine Ma has substantially the same construction as that of the resistance welding machine M except that an intermediate electrode 10a and a short-circuit conductor 10b are added to the resistance welding machine M described above. The intermediate electrode 10a is fixed to a lower end peripheral wall part of the upper electrode 10. The short-circuit conductor 10b short-circuits the intermediate electrode 10 and the lower electrode 20. The welded material 30A includes a terminal 30c in stead of the terminal 30a of the welded material 30. This terminal 30c is mounted on the mounting surface of the lower electrode 20. At the same time, the pressurizing surface of the upper electrode depresses the tip part of the coated wire 30b directly on the terminal 30c. Excepting this point, the welded material 30A has substantially the same construction as that of the welded material 30. Note that the welding current, upon entering the upper electrode 1D, flows into the lower electrode via the short-circuit conductor 10b because of an insulating property of the coating of the coated wire 30b; and the welding current runs as a main current Im into the lower electrode 20 via the welded material 30A with the exfoliation of the coat.
The control unit Ea includes a current detection circuit 70A in addition to the current detection circuit 70 described in the first embodiment. This current detection circuit 70A detects the main current Im flowing across the lower electrode 20 with the aid of a current detection coil 73. A result of this detection is detected and amplified as a detected main current by means of a main current detection circuit 74. Besides, the control unit Ea has an arithmetic processing unit 100A. This arithmetic processing circuit 100A effects, when actuated, an arithmetic to increase the welding pressure P on the welded material 30A up to a value enough to exfoliated the coating of the coated wire 30b. With an end of the enhancement of this welding pressure P, the circuit 100A performs an arithmetic necessary for outputting the welding current I from the welding power supply 60.
Thereafter, the arithmetic processing circuit 100A computes effective values IRMS, VRMS thereof on the basis of the detected welding current given from the welding current detection circuit 70 and the inter-electrode voltage given from the voltage detection circuit 80 per sampling timing cycle. Based on the two effective values IRMS, VRMS, the circuit 100 computes the inter-electrode resistance R (=VRMS/IRMS) between the upper electrode 10 and the lower electrode 20. Simultaneously, the circuit 100 compares two continuous inter-electrode resistances among the inter-electrode resistances R. The circuit 100 sequentially selects the smaller of the two electrode resistances thus compared. Further, the latest selected inter-electrode resistance R coincides with a selected inter-electrode resistance R just before it, thereby reaching the maximum value. Concomitantly, the arithmetic processing circuit 100A determines the same latest selected inter-electrode resistance R as a maximum resistance Rmax. Thereafter, the circuit 100A computes an effective value IMRMS on the basis of the detected main current given from the current detection circuit 70A per sampling timing cycle. The circuit 100A performs an arithmetic to obtain an input power PW through a time-based integration of the product of a square of each effective value IMRMS and the inter-electrode resistance R. Besides, a rising resistance RL from the maximum resistance Rmax is computed based on the inter electrode resistance R. A falling resistance setting circuit 110A sets a falling resistance RLO which will be stated later. An input power setting circuit 120A sets a predetermined power PWo that will hereafter be explained.
By the way, the following is a reason why concepts of the inter-electrode resistance R, the maximum resistance Rmax, the input power PW and the falling resistance RL are introduced, as described before, into the arithmetic operation by the arithmetic processing circuit 100A. There will be explained why concepts of the falling resistance RLO set by the falling resistance setting circuit 110A and the input power PWo set by the input power setting circuit 120A are introduced thereinto. Where the coated wire is resistance welded to the terminal by the triple electrode type resistance welding machine Ma, the welding conditions such as a welding current, a conducting time and a welding pressure, etc. are fixed. Consequently, the coating exfoliating time and the welding time fluctuate, resulting in deteriorations of the welding strength and of welding spark. The present inventors found out from repetitions of various tests that the reliability on the resistance welding quality can be remarkably improved by eliminating the drawbacks described above. This involves performing the resistance welding in the following manner by effectively utilizing such a phenomenon that the inter-electrode resistance is reduced with an inflow of the main current Im when the coating is peeled off. Namely, the inventors examined how the inter-electrode resistance R at the time of obtaining a good resistance welding quality between the coated wire and the terminal varies in the course of the resistance welding. It was known that this inter-electrode resistance R exhibits a convex-like variation tendency as shown in the left half of a characteristic curve Le in FIG. 7; and it has a maximum resistance Rmax.
In such a case, the fact that the inter-electrode resistance R increases toward the maximum resistance Rmax and deceases after reaching the same maximum resistance Rmax is derived from the following reason. At an initial stage where the two electrodes 10, 20, the intermediate electrode 10a and the short-circuit conductor 10b are charged with electricity, the welding current flows mainly across the intermediate electrode 10a and the short-circuit conductor 10b in relation with the coated wire and the coat. Temperatures of the two electrodes 10, 20 are therefore low. Hence, each internal resistance of the two electrodes 10, 20 is small, the inter-electrode resistance R is also small. Thereafter, the current running across the short-circuit conductor 10b is reduced with progressions of the coating exfoliation and pressurization, whereas the current flowing across the two electrodes 10, 20 increases. The temperatures of the two electrodes 10, 20 rise. Each internal resistance thereof augments, and the inter-electrode resistance R likewise increases. Then, the inter-electrode resistance R comes to the maximum resistance Rmax, and the coating is concomitantly peeled off. Thereafter, the inter-electrode resistance R decreases because of a parallel circuit constructed of the intermediate electrode 10a, the short-circuit conductor 10b, the two electrodes 10, 20 and the wire part. The above-mentioned is the reason why the inter-electrode resistance R decreases after reaching the maximum resistance Rmax. Further, a complete coating exfoliation of the coated wire (the direct contact or complete electrical contact between the wire and terminal) starts when R=Rmax. This is understood from the fact that the main current Im flows as indicated by the symbol Lf in FIG. 7 when the inter-electrode resistance R takes the maximum resistance Rmax. It can be also known from this fact that the resistance welding is separable into the coating exfoliating process and the welding process.
Furthermore, a degree of reduction of the inter-electrode resistance R after increasing up to the maximum resistance Rmax is expressed by a falling resistance RL as indicated by a characteristic curve Le in FIG. 7. This falling resistance RL proved to be closely correlative to the coating exfoliated area of the coated wire as shown in FIG. 8. It was also known from the above-mentioned that if the welding current flows till the falling resistance RL is reduced down to a preset value RLO (value for securing a necessary coating exfoliated area), the coating exfoliated state of the coated wire can be always kept stable with no unevenness.
Besides, a relationship between a degree of collapse of the coated wire and a joint efficiency was examined in many ways through tests in order to improve the joint efficiency and secure a stable welding strength by making proper the degree of collapse of the coated wire in the welding process. The following was known therefrom. After the falling resistance RL has reached the set falling resistance value RLO explained above, the conduction of the welding current is temporarily halted for a cooling or temperature keeping period. Then, the welding pressure P applied via the upper electrode on the coated wire rises to a value enough to restrain softening of the wire through short-time welding as shown by a characteristic curve Lg in FIG. 7. Further, the input power PW corresponding to an establishment of RL - RLO when finishing the coating exfoliation comes to a preset input power PWo (a value necessary for securing a connected area corresponding to the stable welding strength between the wire 32 and the terminal as shown in FIG. 9). At this time, the conduction of the welding current halts. Hereupon, it is possible to improve the joint efficiency (see FIG. 10) under the restraint of softening of the wire and obtain the stable welding strength.
A comparative judging circuit 130A commands, when actuated, the welding pressure control circuit 150 to increase the opening of the proportional control valve 50 up to a value of the welding pressure P enough to exfoliate the coating of the coated wire 30b. Thereafter, the circuit 130A commands the current control circuit 140 to output the welding current I from the welding power supply 60. Further, the comparative judging circuit 130 compares each falling resistance RL given from the arithmetic processing circuit 100A with the falling resistance RLO given from the falling resistance setting circuit 110A. When RL=RLO is established, the circuit 130A makes such judgments that there are necessities to temporarily halt the conduction of the welding current I and to increase the welding pressure P on the welded material 30A. In addition, the comparative judging circuit 130A commands the current control circuit 140 to resume the conduction of the welding current I with a stability of the welding pressure P after a predetermined time (needed for stabilizing the welding pressure) has elapsed in connection with enhancing of the welding pressure P through the arithmetic processing circuit 100A. The comparative judging circuit 130A compares each input power PW from the arithmetic processing circuit 100A with the set input power PWo from the input power setting circuit 120A. The circuit 130A makes judgments to halt the conduction of the welding current and to finish the pressurization on the welded material 30A when establishing PW=PWo. Other constructions are substantially the same as those in the first embodiment.
In accordance with the thus constructed second embodiment, it is assumed that the welded material 30A is, as illustrated in FIG. 6, mounted on the mounting surface of the lower electrode 20 under the pressurizing surface of the upper electrode 10 of the resistance welding machine Ma. In this instance, it is also presumed that both the welding pressure P on the welded material 30A and the welding current from the welding current power supply 60 are zero. On the occasion of the resistance welding on the welded material 30A, however, if the control unit Ea is brought into an active state when the time t=t0 in FIG. 7, the arithmetic processing circuit 100A effects the arithmetic to enhance the welding pressure P to a value enough to peel off the coating of the coated wire 30b. With this action, the comparative judging circuit 130A outputs, to the welding pressure control circuit 150, a command needed for setting the opening of the proportional control valve 50 to a value corresponding to the coating exfoliation value of the welding pressure P. Consequently, the welding pressure control circuit 150 controls the opening of the proportional control valve 50. The air flow from the pneumatic source 50a is thereby pressure-fed to the air cylinder 40. Besides, this air cylinder 40 moves down the upper electrode 10 in accordance with the air flow from the proportional control valve 50, thereby applying the welding pressure P as a value enough to peel off the coating on the welded material 30A.
Subsequently, when the time t=t1 in FIG. 7 with the increase in the welding pressure P, the arithmetic processing circuit 100A executes an arithmetic operation required for outputting the welding current I from the welding power supply 60. With this operation, the comparative judging circuit 130A outputs, to the current control circuit 140, a command to output the welding current I from the welding power supply 60. For this purpose, the relay 60a closes the relay switch Y as in the first embodiment discussed above. Concomitantly, the welding current I flows from the welding power supply 60 via the power supply conductor 61 to the upper electrode 10. Hereupon, this inflow welding current runs into the lower electrode 20 via the intermediate electrode 10a and the short-circuit conductor 10b. Thereafter, the welding current runs into a power supply conductor 62 (see the symbol Ld in FIG. 7). At this time, the welding current I is detected by the welding current detection circuit 70, and simultaneously, the inter-electrode voltage V between the upper and lower electrodes 10, 20 is detected by the voltage detection circuit 80.
After effecting the above-mentioned output arithmetic process of the welding current I, the arithmetic processing circuit 100A computes the effective values IRMS, VRMS thereof on the basis of the detected welding current given from the welding current detection circuit 70 and the inter-electrode voltage given from the voltage detection circuit 80 per sampling timing cycle. Based on the two effective values IRMS, VRMS, the circuit 100 computes an inter-electrode resistance R between the upper electrode 10 and the lower electrode 20. Simultaneously, the circuit 100 compares two continuous inter-electrode resistances R among the inter-electrode resistances R. The circuit 100 sequentially selects the smaller of the two electrode resistances thus compared. In such a case, as shown in FIG. 7, the inter-electrode resistance R starts increasing from the time when t=t1. The exfoliating process of the coating 33 of the coated wire 30b is thereby started.
During such a process, when t=t2 as shown in FIG, 7, the latest selected inter-electrode resistance R coincides with a selected inter-electrode resistance R just before it, thereby reaching the maximum value. Then, the arithmetic processing circuit 100A determines the same latest selected inter-electrode resistance R as a maximum resistance Rmax. At this moment, the coating exfoliation of the coated wire 30b is started. The welding current as the main current Im running across the upper electrode 10 therefore flows into the lower electrode 20 via the welded material 30A (see FIG. 7). Thereafter, the arithmetic processing circuit 100A computes the effective value IMRMS on the basis of the main current detected by the current detection circuit 70A per sampling timing cycle. The circuit 100A computes the input power PW through the time-based integration of the product of a square of each effective value IMRMS and the inter-electrode resistance R. Further, the circuit 100A computes the falling resistance RL from the maximum resistance Rmax on the basis of the inter-electrode resistance R.
Thereafter, when the time t=t3 in FIG. 7, the latest falling resistance RL comes to a falling resistance RLO. Hereupon, the comparative judging circuit 130A judges that RL=RLO is established. The circuit 130A also make judgments that the conduction of the welding current I is required to be temporarily halted and that the welding pressure P on the welded material 30A is required to be increased above the coating exfoliation value. Then, the current control circuit 140 causes the relay switch Y of the relay 60a to be temporarily closed in response to the judgment to temporarily halt the conduction of the welding current I which has been made by the comparative judging circuit 130A. The output of the welding current I from the welding power supply 60 is temporarily stopped. Besides, the welding pressure control circuit 150 controls the proportional control valve 50 to expand its valve opening in response to the judgment to enhance the welding pressure P that has been given from the comparative judging circuit 130A. Consequently, the quantity of the air flow pressure-fed to the air cylinder 40 from the proportional control valve 50 augments. The upper electrode 10 is further moved down, while the welding press P on the welded material 30A increased (see time t=t3˜t4 in FIG. 7).
The enhancement of the welding pressure P is completed when the time t=t4. After a predetermined time has passed, the welding pressure P is stabilized. Then, the comparative judging circuit 130A makes a judgment to resume the conduction of the welding current I. Concomitantly, the current control circuit 140 controls the relay 60a to close again the relay switch Y of the relay 60a. Therefore, the welding current I as the main current flows again into the lower electrode 20 across the upper electrode 10 and the welded material 30A from the welding power supply 60. It is therefore follows that the operation is shifted to the welding process of the welded material 30A after the coating has been exfoliated.
In this state, the welding between the terminal 30c and the tip part of the coat-exfoliated wire 32 from the coated wire 30b progresses under the foregoing stabilized condition where the welding pressure P is increased. Thereafter, the input power reaches the set input power PWo in the arithmetic processing circuit 100A when the time t=t5. Then, the comparative judging circuit 130A judges that PW=PWo is established in cooperation with the arithmetic processing circuit 100A and the input power setting circuit 120A as well. The circuit 130 also makes a judgment to halt the conduction of the welding current I. At the same time, the circuit 130 make a judgment to stop an application of the welding pressure on the welded material 30A. Subsequently, the current control circuit 140 controls the relay 60a to open the relay switch Y in response to the judgment to halt the conduction of the welding current I from the welding power supply 60 that has been made by the comparative judging circuit 130A. The output of the welding current I from the welding power supply 60 is thereby finished. Besides, the proportional control valve 50 is controlled to be closed by the welding pressure control circuit 150 in response to the judgment to halt the application of the welding pressure that has been given from the comparative judging circuit 130A. Ended is the pressure-feed of the air flow to the upper electrode 20 through the air cylinder 40.
As discussed above, in accordance with the second embodiment, the welding pressure P acts on the welded material 30A with a value enough to peel off the coating of the coated wire 30b in the coat exfoliating process. Simultaneously, the short-circuit conductor 10b conducts the welding current I. This continues till the falling resistance RL decreases down to the set falling resistance RLO after the inter-electrode resistance R has reached the maximum resistance Rmax. Then, the coating exfoliating process is ended off when RL=RLO is established, and the operation shifts to the welding process. The conduction of the welding current I temporarily halts, and simultaneously the welding pressure P is stepped up. With the welding pressure P stabilized afterwards, the conduction of the welding current I is restarted. The welding process is finished when the input power PW reaches the set input power PWo. Hence, when the welded material 30A undergoes the resistance welding in the resistance welding machine Ma, this resistance welding control is conducted while being separated in terms of time into the coating exfoliating process and the resistance welding process as in the first embodiment. When establishing RL=RLO, the coating exfoliating process is completed. Hence, the stable coating-exfoliated state is attainable. Further, The tip part of the wire 33 is resistance-welded to the terminal 30c in the welding process under the enhanced welding pressure P after the coating has been peeled off. This resistance welding is therefore attainable with a stabilized welding strength and a high joint efficiency without causing excessive softening of the wire 32. As a result, the resistance welding machine Ma is capable of attaining the high quality resistance welding of the welded material 30A without causing deteriorations of the coat exfoliation and welding.
Next, a third embodiment of the present invention will be described. The third embodiment is characterized in terms of construction by adopting a control unit Eb as shown in FIG. 11 in place of the control unit E stated in the first embodiment. The control unit Eb includes effective value arithmetic circuits 200, 210 connected respectively to the welding current detection circuit 70 and the voltage detection circuit 80 described in the first embodiment. The effective value arithmetic circuit 200 is composed of an absolute value circuit 200a connected to the welding current detection circuit 70 and a square-averaging circuit 200b connected to this absolute value circuit 200a. Thus, the absolute value circuit 200a takes an absolute value of the detected welding current from the welding current detection circuit 70 and generates an absolute value signal. The square-averaging circuit 200b effects square-averaging of the absolute value signals given from the absolute value circuit 200a. The circuit square-averaging circuit 200b computes an effective value (corresponding to the effective value IRMS of the welding current explained in the first embodiment) from a square-averaged result and outputs it in the form of a welding current effective value signal. The effective value arithmetic circuit 210 comprises an absolute value circuit 210a connected to the voltage detection circuit 80 and a square-averaging circuit 210b connected to this absolute value circuit 210a. Thus, the absolute value circuit 210a takes an absolute value of the inter-electrode voltage V and generates an absolute value signal. The square-averaging circuit 210b performs square-averaging of the absolute value signals given from the absolute value circuit 210a. This square-averaging circuit 210b computes an effective value (corresponding to the effective value VRMS of the inter-electrode voltage stated in the first embodiment) from a square-averaged result and outputs it in the form of an inter-electrode voltage effective value signal.
Further, the control unit Eb includes low-pass filters 220a, 220b and 220c (hereafter refereed to as LPF 220a, LPF 220b and LPF 220c) connected respectively to the effective value arithmetic circuits 200, 210 and the displacement quantity detection circuit 90. Cut-off frequencies Fc of the LPFs 220a, 220b, 220c are all set to 60 (Hz). Thus, the LPF 220a eliminates a frequency component higher than 60 (Hz) out of frequency components of the welding current effective value signals transmitted from the square-averaging circuit 200b of the effective value arithmetic circuit 200. The LPF 220a treats the remaining frequency components to generate filter current signals. The LPF 220b removes a frequency component higher than 60 (Hz) out of the frequency components of the inter-electrode voltage effective value signals transmitted from the square-averaging circuit 210b of the effective value arithmetic circuit 210. The LPF 220b treats the remaining frequency components to generate filter voltage signals. Further, the LPF 220c removes a frequency component higher than 60 (Hz) out of the frequency components of the electrode displacement quantity outputs given from the displacement quantity detection circuit 90. The LPF 220c treats the remaining frequency components to generate filter displacement quantity signals.
An analog multiplexer 230 sequentially selects the filter current signal, the filter voltage signal and the filter displacement quantity signal respectively from the LPFs 220a, 220b, 220c under the control of a microcomputer 250 which will be mentioned alter. The analog multiplexer 230 then outputs these signals to an A-D converter 240. In such a case, the filter current signal from the LPF 220a is outputted via a first channel 1ch of the analog multiplexer 230. The filter voltage signal from the LPF 220b is outputted via a second channel 2ch of the analog multiplexer 230. Further, the filter displacement quantity signal from the LPF 220c is outputted via a third channel 3ch of the analog multiplexer 230. The A-D converter 240 sequentially effects digital conversions of the filter current signal, the filter voltage signal and the filter displacement quantity signal from the analog multiplexer 230 into a digital current signal, a digital voltage signal and a digital displacement quantity signal. The microcomputer 250 executes a computer program in cooperation with the A-D converter 240 in conformity with flowcharts of FIGS. 12˜14. During this execution, the microcomputer 250 performs an arithmetic process needed for the control of a D-A converter 260. However, the computer program described above is previously stored in a ROM of the microcomputer 250.
The D-A converter 260 performs an analog conversion of welding pressure data outputted, as will be stated later, from the microcomputer 250. The D-A converter 260 outputs the data as a welding pressure output signal to a driving circuit 270a. The driving circuit 270a drives the proportional control valve 50 to set a valve opening thereof to a value corresponding to the value of the welding pressure output signal in response to a welding pressure output signal from the D-A converter 260. The driving circuit 270b drives the relay 60a to selectively excite the relay coil Ry thereof in response to a conduction output signal indicating the conduction from the welding power supply 60 that is generated from the microcomputer 250 as will be explained below. Other constructions are the same as those in the first embodiment.
In the thus constructed third embodiment, it is assumed that the welded material 30 is, as in the first embodiment shown in FIG. 1, mounted on the mounting surface 21 of the lower electrode 20 under the pressuring surface 11 of the upper electrode 10 of the resistance welding machine M. It is also presumed that the welding pressure P on the welded material 30 and the welding current from the welding power supply 60 are both set to zero. Thus, the control unit Eb is put into the active state in the resistance welding of the welded material 30. Then, the microcomputer 250 starts executing the computer program in accordance with the flowcharts of FIGS. 12˜14 in step 300. Hereupon, the microcomputer 250 sets the welding pressure P to a predetermined initial welding pressure value (see t=t1 in FIG. 1) enough to exfoliate the coating of a coated conductor 30b in step 310. The microcomputer 250 then outputs the welding pressure P as welding pressure data.
Then, the D-A converter 260 analog-converts the welding pressure data given from the microcomputer 250 and outputs the data as a welding pressure output signal. In response to this action, a driving circuit 270a drives the proportional control valve 50 to set a valve opening thereof to a value corresponding to the value (the above-mentioned initial welding pressure value) of the welding pressure output signal. Therefore, the proportional control valve 50 serves to pressure-feed the air flow from a pneumatic source 50a to the air cylinder 40 in accordance with the valve opening thereof. Besides, this air cylinder 40 moves down the upper electrode 10 in accordance with the air flow fed from the proportional control valve 50. The air cylinder 40 starts exerting the welding pressure P (=the initial welding pressure value described above) as a value enough to peel off the coating on the welded material 30. At this moment, the displacement quantity detection circuit 90 detects and outputs an electrode displacement quantity X (see t=t0 in FIG. 2) of the upper electrode 10. Subsequently, the microcomputer 250 executes an arithmetic necessary for initiating the conduction from the welding power supply 60 in step 310a and outputs a conduction output signal. Then, the driving circuit 270b excites the relay coil Ry of the relay 60a. Consequently, the relay 60a closes the relay switch Y. In response to this action, the conduction of the welding current I from the welding power supply 60 occurs through the power supply conductor 61, the upper electrode 10, the welded material 30, the lower electrode 20 and the power supply conductor 62. At this time, the welding current I is detected by the welding current detection circuit 70. Simultaneously, the inter-electrode voltage V between the upper and lower electrodes 10, 20 is detected by the voltage detection circuit 80.
When the arithmetic in step 310a is thus ended off, the microcomputer 250 selects the first channel 1ch of the analog multiplexer 230 in step 320. In response to this selection, the analog multiplexer 230 outputs the filter current signal to the A-D converter 240 from the LPF 220a via the first channel 1ch. Then, this A-D converter 240 digital-converts the same filter current signal into a digital current signal and outputs it to the microcomputer 250. The microcomputer 250 therefore sets a value of the same digital current signal as an effective value IRMS in step 320a. Subsequently, the microcomputer 250 selects the second channel 2ch of the analog multiplexer 230 in step 330. Then, the analog multiplexer 230 outputs the filter voltage signal to the A-D converter 240 from the LPF 220b via the second channel 2ch.
Then, this A-D converter 240 digital-converts the same filter voltage signal into a digital voltage signal and outputs it to the microcomputer 250. The microcomputer 250 therefore sets a value of the same digital voltage signal as an effective value VRMS in step 330a. Further, the microcomputer 250 selects the third channel 3ch of the analog multiplexer 230 in step 340. The analog multiplexer 230 outputs the filter displacement quantity signal to the A-D converter 240 from the LPF 220c via the third channel 3ch. Then, this A-D converter 240 digital-converts the same filter displacement quantity signal into a digital displacement quantity signal and outputs it to the microcomputer 250. The microcomputer 250 therefore sets a value of the same digital displacement quantity signal as an electrode displacement quantity X in step 340a.
Thereafter, in step 350, the microcomputer 250 computes the inter-electrode resistance R between the upper and lower electrodes 10, 20 on the basis of the effective value IRMS obtained in step 320a and the effective value VRMS obtained in step 330. Based on the fact that this inter-electrode resistance R is larger than an initial resistance value Rini in step 300, the microcomputer 250 makes a judgment of [NO]. further in step 360a, the microcomputer 250 sets the inter-electrode resistance R as a present-stage minimum resistance Rmin in step 350. Hereafter, the arithmetic operations for a circulation through steps 320˜360a are repeated substantially in the same way. Note that as in the first embodiment, both of the inter-electrode resistance R and the electrode displacement quantity X start decreasing in such a course. Hence, this implies an onset of the exfoliating process of the coating 33 of the coated wire 30a.
During such repetitive arithmetic processes, the latest inter-electrode resistance R instep 350 coincides with the minimum resistance Rmin in step 360a just before it. If so, the microcomputer 250 makes a judgment of [YES] in step 360. In step 360b, the same latest inter-electrode resistance R is temporarily stored as the minimum resistance Rmin. Besides, in step 360b, the microcomputer 250 determines, as a minimum displacement quantity Xmin, the latest electrode displacement quantity X in step 340a that corresponds to the same minimum resistance Rmin and temporarily stores the minimum displacement quantity Xmin.
Subsequently, in steps 370, 370a, 380, 380a, 390, the microcomputer 250 performs the same arithmetic operations as those in foregoing steps 320, 320a, 330, 330a, 350 in cooperation with the analog multiplexer 230 and the A-D converter 240. Thus, the microcomputer 250 sets the effective values IRMS, VRMS and computes the inter-electrode voltage R. Thereafter, the microcomputer 250 computes a difference between the inter-electrode resistance R in step 390 and the minimum resistance Rmin in step 360a. The microcomputer 250 sets this difference as a rising resistance RU. In next step 400, the same rising resistance RU is comparatively judged with respect to the set rising resistance value RUO stated in the first embodiment. In the third embodiment, however, the set rising resistance value RUO is stored beforehand in the ROM of the microcomputer 250. At the present stage, the rising resistance RU in step 390a is smaller than the set rising resistance value RUO. Therefore, the microcomputer 250 makes a judgment of [NO] in step 400 to return the computer program to step 370. Hereinafter, the arithmetic operations for a circulation through steps 370˜400 are repeated.
During a repetition of such arithmetic operations, if the rising resistance RU in step 390a is equal to or larger than the set rising resistance value RUO, the microcomputer 250 makes a judgment of [YES] in step 400. The microcomputer 250 executes an arithmetic to lower the welding pressure P on the welded material 30 by a predetermined welding pressure width from the initial welding pressure value (i.e., the coating exfoliating value) in step 400a. The microcomputer 250 outputs a difference between the predetermined welding pressure value and the predetermined welding pressure width as lowered welding pressure data. Besides, in step 400b, the microcomputer 250 effects an arithmetic to temporarily halt the conduction from the welding power supply 60, thereby temporarily stopping the output of conduction output signals.
Then, the D-A converter 260 analog-converts the lowered welding pressure data from the microcomputer 250 into a welding pressure output signal and outputs it. In response to this action, the driving circuit 270a drives the proportional control valve 50 to reduce the valve opening thereof down to a value corresponding to the difference between the predetermined welding pressure value and the predetermined welding pressure width. Consequently, the proportional control valve 50 reduces the air flow to the air cylinder 40 from the pneumatic source 50a in accordance with the decreased valve opening. The air cylinder 40 lowers the welding pressure on the welded material 30 through the upper electrode 10 in accordance with the reduction of the same air flow. Concomitantly, the decrease in the electrode displacement quantity X ceases. Further, the temporary halt of the output of the conduction output signals from the microcomputer 250 is accompanied by a temporary demagnetization of the relay coil Ry of the relay 60a by the driving circuit 270b. Therefore, the output of the welding current I from the welding power supply 60 is temporarily stopped.
Thereafter, with a passage of a predetermined time (stored beforehand in the ROM of the microcomputer 250) necessary for stabilizing the welding pressure P with a completion of reduction thereof, the microcomputer 250 makes a judgment of[YES] in step 410. The microcomputer 250 performs an arithmetic to resume the conduction from the welding power supply 60 in step 410a and outputs again the conduction output signal. In consequence, the relay 60a is driven by the driving circuit 270b. The relay 60a excited by the relay coil Ry thereof closes the relay switch Y to output again the welding current I from the welding power supply 60. The conduction of the welding current I again takes place through the power supply conductor 61, the upper electrode 10, the welded material 30, the lower electrode 20 and the power supply conductor 62. It therefore follows that the operation shifts to the welding process of the welded material 30 after the coating has been exfoliated as in the first embodiment.
In such a course, as in the first embodiment, the welding between the terminal and the tip part of the coating-exfoliated wire 32 from the coated wire 30b progresses under the stabilized condition where the welding pressure P is lowered as shown above. The inter-electrode resistance R decreases rectilinearly on one hand, and the electrode displacement quantity X is reduced rectilinearly on the other hand. At such a stage, after performing the arithmetic in step 410a, the microcomputer 250 selects the third channel 3ch of the analog multiplexer 230 in step 420. Then, the analog multiplexer 230 outputs, to the A-D converter 240, the displacement quantity filter signal transmitted from the LPF 220c. This A-D converter 240 digital-converts the same displacement quantity filter signal into a digital displacement quantity signal and outputs it to the microcomputer 250.
Subsequently, the microcomputer 250 sets a value of the same digital displacement quantity signal as an electrode displacement quantity X in step 420a. In step 420b, the microcomputer 250 computes a difference between the same electrode displacement quantity X and the minimum displacement quantity Xmin in step 360c. This arithmetic difference is updated as the electrode displacement quantity X. Then, the microcomputer 250 makes a judgment of [NO] in step 430 on the basis of the fact that the same updated electrode displacement quantity X is smaller than the set electrode displacement quantity Xo stated in the first embodiment. The computer program goes back to step 420. The set electrode displacement quantity Xo is, however, previously stored in the ROM of the microcomputer 250.
Hereafter, the latest updated electrode displacement quantity X is equal to or greater than the set electrode displacement quantity Xo during a repetition of the arithmetic operations for a circulation through steps 420˜430. Then, the microcomputer 250 makes a judgment of [YES] in step 430. The microcomputer 250 finishes outputting the conduction output signal to end off the output of the welding current I from the welding power supply 60 in step 430a. Further, the microcomputer 250 finishes outputting the welding pressure output signal to end off the pressurization on the welded material 30 through the upper electrode 10 in step 430b. Then, the driving circuit 270b demagnetizes the relay coil Ry of the relay 60a with the halt of the output of the conduction output signal from the microcomputer 250. Upon opening the relay switch Y, the relay 60a finishes outputting the welding current I from the welding power supply 60. Besides, the driving circuit 270a drives the proportional control valve 50 to make its valve opening zero with an end of the output of the welding pressure signal from the microcomputer 250. The pressurization through the upper electrode 10 is thereby ended off. Other actions are the same as those in the first embodiment. Therefore, the same effects as those in the first embodiment can be attained even by utilizing the above-mentioned arithmetic operations by the microcomputer 250.
Next, a fourth embodiment of the present invention will be described. The fourth embodiment is characterized in terms of construction by adopting a control unit Ec as shown in FIG. 15 in place of the control unit Ea stated in the second embodiment. The control unit Ec includes effective value arithmetic circuits 500, 510, 520 connected respectively to the welding current detection circuit 70, the current detection circuit 70A and the voltage detection circuit 80 described in the first embodiment. The effective value arithmetic circuit 500 is composed of an absolute value circuit 500a and a square-averaging circuit 500b having the same constructions and functions as those of the absolute value circuit 200a and the square-averaging circuit 200b of the effective value arithmetic circuit 200 describe din the third embodiment. Thus, the absolute value circuit 500a takes an absolute value of the detected welding current from the welding current detection circuit 70 and generates an absolute value signal. The square-averaging circuit 500b effects square-averaging of the absolute value signals given from the absolute value circuit 500a. The circuit square-averaging circuit 500b computes an effective value (corresponding to the effective value IRMS of the welding current explained in the second embodiment) from a square-averaged result thereof and outputs it in the form of a welding current effective value signal.
The effective value arithmetic circuit 510 comprises an absolute value circuit 510a connected to the voltage detection circuit 70A and a square-averaging circuit 510b connected to this absolute value circuit 510a. Thus, the absolute value circuit 510a takes an absolute value of the detected main current and generates an absolute value signal. The square-averaging circuit 510b performs square-averaging of the absolute value signals given from the absolute value circuit 510a. This square-averaging circuit 510b computes an effective value (corresponding to the effective value IMRMS of the detected main current stated in the second embodiment) from a square-averaged result thereof and outputs it in the form of a main current effective value signal. The effective value arithmetic circuit 520 is composed of an absolute value circuit 520a and a square-averaging circuit 520b having the same constructions and functions as those of the absolute value circuit 210a and the square-averaging circuit 210b of the effective value arithmetic circuit 2210 described in the third embodiment. Thus, the absolute value circuit 520a takes an absolute value of the inter-electrode voltage V from the voltage detection circuit 80 and generates an absolute value signal. The square-averaging circuit 520b square-averages the absolute value signals transmitted form the absolute value circuit 520. The square-averaging circuit 520b computes an effective value (corresponding to the effective value VRMS of the inter-electrode voltage mentioned in the second embodiment) from a square-averaged result thereof and outputs it as an inter-electrode voltage effective value signal.
Further, the control unit Ec includes low-pass filters 530a, 530b and 530c (hereafter referred to as LPF 530a, LPF 530b and LPF 530c) connected respectively to the effective value arithmetic circuits 500, 510, 520. Cut-off frequencies Fc of these LPFs 530a, 530b, 530c are all set to 60 (Hz). Thus, the LPF 530a eliminates a frequency component higher than 60 (Hz) out of frequency components of the welding current effective value signals transmitted from the square-averaging circuit 500b of the effective value arithmetic circuit 500. The LPF 530a treats the remaining frequency components to generate filter current signals. The LPF 530b removes a frequency component higher than 60 (Hz) out of the frequency components of the main current effective value signals transmitted from the square-averaging circuit 510b of the effective value arithmetic circuit 510. The LPF 530b treats the remaining frequency components to generate filter main current signals. Further, the LPF 530c removes a frequency component higher than 60 (Hz) out of the frequency components of the voltage effective value signals given from the effective value arithmetic circuit 520. The LPF 530c treats the remaining frequency components to generate filter voltage signals.
An analog multiplexer 540 sequentially selects the filter current signal, the filter main current signal and the filter voltage signal respectively from the LPFs 530a, 530b, 530c under the control of a microcomputer 560 which will be mentioned alter. The analog multiplexer 540 then outputs these signals to an A-D converter 550. In such a case, the filter current signal from the LPF 530a is outputted via a first channel 1ch of the analog multiplexer 540. The filter main current signal from the LPF 530b is outputted via a second channel 2ch of the analog multiplexer 540. Further, the filter voltage signal from the LPF 530c is outputted via a third channel 3ch of the analog multiplexer 540. The A-D converter 550 sequentially effects digital conversions of the filter current signal, the filter main current signal and the filter voltage signal from the analog multiplexer 540 into a digital current signal, a digital main current signal and a digital voltage signal. The microcomputer 560 executes a computer program in cooperation with the A-D converter 550 in conformity with flowcharts of FIGS. 16˜18. During this execution, the microcomputer 560 performs an arithmetic process needed for the control of a D-A converter 570. However, the computer program described above is previously stored in a ROM of the microcomputer 560.
The D-A converter 570 performs an analog conversion of welding pressure data outputted, as will be stated later, from the microcomputer 560. The D-A converter 570 outputs the data as a welding pressure output signal to a driving circuit 580a. The driving circuit 580a drives the proportional control valve 50 to set a valve opening thereof to a value corresponding to the value of the same welding pressure output signal in response to a welding pressure output signal from the D-A converter 570. The driving circuit 580b drives the relay 60a to selectively excite the relay coil Ry thereof in response to a conduction output signal indicating the conduction from the welding power supply 60 that is generated from the microcomputer 560 as will be explained below. Other constructions are the same as those in the second embodiment.
In the thus constructed fourth embodiment, it is assumed that the welded material 30A is, as in the first embodiment, mounted on the mounting surface of the lower electrode 20 under the pressuring surface of the upper electrode 10 of the resistance welding machine Ma. It is also presumed that the welding pressure P on the welded material 30A and the welding current from the welding power supply 60 are both set to zero. Thus, the control unit Ec is put into the active state in the resistance welding of the welded material 30A. Then, the microcomputer 560 starts executing the computer program in accordance with the flowcharts of FIGS. 16˜18 in step 600. Hereupon, the microcomputer 560 sets the welding pressure P to a predetermined initial welding pressure value enough to exfoliate the coating of a coated conductor 30b in step 610. The microcomputer 560 then outputs the welding pressure P as welding pressure data.
Then, the D-A converter 570 analog-converts the welding pressure data given from the microcomputer 560 and outputs the data as a welding pressure output signal. In response to this action, a driving circuit 270a drives the proportional control valve 50 to set a valve opening thereof to a value corresponding to the value (the above-mentioned initial welding pressure value) of the same welding pressure output signal. Therefore, the proportional control valve 50 serves to pressure-feed the air flow from a pneumatic source 50a to the air cylinder 40 in accordance with the valve opening thereof. Besides, this air cylinder 40 moves down the upper electrode 10 in accordance with the air flow fed from the proportional control valve 50. The air cylinder 40 starts exerting the welding pressure P (=the initial welding pressure value described above) as a value enough to peel off the coating.
Subsequently, the microcomputer 560 executes an arithmetic necessary for initiating the conduction of the current from the welding power supply 60 in step 610a and outputs a conduction output signal. Then, the driving circuit 580b excites the relay coil Ry of the relay 60a. Consequently, the relay 60a closes the relay switch Y. In response to this action, the welding current I from the welding power supply 60 flows across the upper electrode 10 via the power supply conductor 61. Then, this inflow welding current I flows into the power supply conductor 62 after running across the lower electrode 20 via the intermediate electrode 10a and the short-circuit conductor 10b because of an insulating property of the coating of the coated wire 30b. At this time, the welding current I is detected by the welding current detection circuit 70. Simultaneously, the inter-electrode voltage V between the upper and lower electrodes 10, 20 is detected by the voltage detection circuit 80.
When the arithmetic in step 610a is thus ended off, the microcomputer 560 selects the first channel 1ch of the analog multiplexer 540 in step 620. In response to this selection, the analog multiplexer 540 outputs the filter current signal to the A-D converter 550 from the LPF 530a via the first channel 1ch. Then, this A-D converter 550 digital-converts the same filter current signal into a digital current signal and outputs it to the microcomputer 560. The microcomputer 560 therefore sets a value of the same digital current signal as an effective value IRMS in step 620a. Subsequently, the microcomputer 560 selects the third channel 3ch of the analog multiplexer 540 in step 630. Then, the analog multiplexer 230 outputs the filter voltage signal to the A-D converter 550 from the LPF 530c via the third channel 3ch. Then, this A-D converter 550 digital-converts the same filter voltage signal into a digital voltage signal and outputs it to the microcomputer 560. The microcomputer 560 therefore sets a value of the same digital voltage signal as an effective value VRMS in step 630a.
Thereafter, in step 640, the microcomputer 560 computes the inter-electrode resistance R between the upper and lower electrodes 10, 20 on the basis of the effective value IRMS obtained in step 620a and the effective value VRMS obtained in step 630a. Based on the fact that this inter-electrode resistance R is smaller than an initial resistance value Rini in step 600 at the present stage, the microcomputer 560 makes a judgment of [NO] in step 650. Further in step 650a, the microcomputer 560 sets the inter-electrode resistance R as a present-stage minimum resistance Rmax in step 650a and returns the computer program to step 620. Hereafter, the arithmetic operations for a circulation through steps 620˜650a are repeated substantially in the same way. Note that in such a course, the inter-electrode resistance R increases as in the second embodiment, and this implies an onset of the exfoliating process of the coating of the coated wire 30b.
In such a state, when the latest inter-electrode resistance R in step 640 reaches the maximum resistance Rmax just before it in step 650a, the microcomputer 560 makes a judgment of [YES] in step 650. The microcomputer 560 temporarily stores the same maximum resistance Rmax. At this time, as in the second embodiment, the exfoliation of the coated wire 30b is started. consequently, the welding current flowing across the upper electrode 10 runs as a main current Im into the lower electrode 20 via the welded material 30A.
After effecting the arithmetic in step 650b, in steps 660, 660a, 670, 670a, 680, the microcomputer 560 performs the same arithmetic operations as those in steps 620˜630a in cooperation with the analog multiplexer 540 and the A-D converter 550. The microcomputer 560 sets the effective values IRMS, VRMS and computes the inter-electrode resistance R. Thereafter in step 690, the microcomputer 560 computes a difference between the inter-electrode resistance R in step 680 and the maximum resistance Rmax in step 650b as the falling resistance RL mentioned in the second embodiment. At the present stage, the falling resistance RL in step 690 is smaller than the set falling resistance RLO mentioned in the second embodiment. Hence, the microcomputer 560 makes a judgment of [NO] in step 700 and returns the computer program to step 660. hereafter, the arithmetic operations for a circulation through steps 660˜700 are similarly repeated. In accordance with the fourth embodiment, however, the set falling resistance RLO is stored beforehand in the ROM of the microcomputer 560.
During a repetition of such arithmetic operations, if the latest falling resistance RL in step 690 is equal to or larger than the set falling resistance RLO, the microcomputer 560 makes a judgment of [YES] in step 700. The microcomputer 560 executes an arithmetic to augment the welding pressure P on the welded material 30A by a predetermined welding pressure width in step 700a. The microcomputer 560 outputs a sum of the predetermined welding pressure value and the predetermined welding pressure width as increased welding pressure data. Besides, in step 700b, the microcomputer 560 effects an arithmetic needed for temporarily halting the conduction from the welding power supply 60, thereby temporarily stopping the output of conduction output signals.
Then, the D-A converter 570 analog-converts the increased welding pressure data from the microcomputer 560 into a welding pressure output signal and outputs it. In response to this action, the driving circuit 580a drives the proportional control valve 50 to increase the valve opening thereof up to a value corresponding to the sum of the predetermined welding pressure value and the predetermined welding pressure width. Consequently, as in the second embodiment, the proportional control valve 50 augments the air flow to the air cylinder 40 from the pneumatic source 50a in accordance with the increased valve opening. The air cylinder 40 further move down the upper electrode, corresponding to the augment in the same air flow, thereby increasing the welding pressure on the welded material 30A through the same upper electrode 10.
Thereafter, with a passage of a predetermined time (stored beforehand in the ROM of the microcomputer 560) necessary for stabilizing the welding pressure P with a completion of enhancement thereof, the microcomputer 560 makes a judgment of [YES] in step 710. The microcomputer 560 performs an arithmetic to resume the conduction from the welding power supply 60 in step 710a and outputs again the conduction output signal. In consequence, the relay 60a is driven by the driving circuit 580b. The relay 60a excited by relay coil Ry thereof closes the relay switch Y to output again the welding current I from the welding power supply 60. Hence, the welding current I from the welding power supply 60 is made to flow again as a main current into the lower electrode 20 via the upper electrode 10 and the welded material 30A. This implies a shift to the welding process of the welded material 30A after the coating has been exfoliated as in the second embodiment.
After the arithmetic operation in step 710a, the microcomputer 560 sets the effective value IRMS in the same way as the arithmetic operations in two steps 620, 620a in cooperation with the analog multiplexer 540 and the A-D converter 550 in two steps 720, 720a. Then, the microcomputer 560 selects the second channel 2ch of the analog multiplexer 540 in step 730. The analog multiplexer 540 outputs the filter main current signal to the A-D converter 550 from the LPF 530b via the second channel 2ch. Then, this Aa-D converter 550 digital-converts the same filter main current signal into a digital main current signal and outputs it to the microcomputer 560. The microcomputer 560 therefore sets a value of the same digital main current signal as an effective value IMRMS thereof in step 730a.
Subsequently, the microcomputer 560 sets the effective value VRMS by effecting the same arithmetic operations as those in two steps 630, 630a in cooperation with the analog multiplexer 540 and the A-D converter 550 in two steps 740, 740a. Thereafter, the microcomputer 560 conducts the same arithmetic operations as those in steps 750, 640. The microcomputer 560 thus computes the inter-electrode resistance R on the basis of the effective values IRMS, VRMS in steps 720a, 740a. Besides, in step 760, the microcomputer 560 computes the input power PW through a time-based integration of the product of the inter-electrode resistance R and a square of the effective value IMRMS in step 730a. At the present stage, the input power in step 760 is smaller than the set input power PWo stated in the second embodiment. The microcomputer 560 therefore makes a judgment of [NO] in step 770 and returns the computer program to step 720. Hereafter, the arithmetic operations for a circulation through steps 720˜770 are repeated.
In such a course, the welding between the terminal 30c and the tip part of the coating-exfoliated wire 32 from the coated wire 30b progresses under the stabilized condition where the welding pressure P is enhanced as shown above. Thereafter, when the latest input power PW in step 760 exceeds the set input power PWo, the microcomputer 560 make a judgment of [YES] in step 770. In step 770a, the microcomputer 560 finishes outputting the conduction output signal to end off the output of the welding current I from the welding power supply 60. Besides, in step 770b, the output of the welding pressure signal is halted to stop the pressurization on the welded material 30A through the upper electrode 10. Then, the driving circuit 580b demagnetizes the relay coil Ry of the relay 60a with the halt of the output of the conduction output signal from the microcomputer 560. The same relay coil 60a works to finish the output of the welding power supply I with closing of the relay switch Y. Further, the driving circuit 580a drives the proportional control valve 50 to make its valve opening zero with an end of the output of the welding pressure output signal from the microcomputer 560. The pressurization through the upper electrode 10 is thereby finished. Other actions are the same as those in the second embodiment. The same effects as those in the second embodiment are thereby attainable even by utilizing the above-mentioned arithmetic operations by the microcomputer 560.
Incidentally, when embodying the present invention, there may be utilized a result of a vicinal-to-welding-part temperature of the coated wire that is detected by an infrared-ray thermometer 801 or the like and a result of a gas generated during the coat exfoliation that is detected by a gas sensor 802 in judging a timing of the coat exfoliation as described in the second or fourth embodiment discussed above.
Further, when embodying the present invention, the mutually continuous two inter-electrode resistances are compared in determining the minimum resistance Rmin (or the maximum resistance Rmax). When a difference therebetween is equal to or smaller than the predetermined difference, the inter-electrode resistance R just before it may be determined as the minimum resistance Rmin (or the maximum resistance Rmax).
Moreover, when embodying the present invention, the power supply frequency of the welding power supply 60 is not limited to 60 (Hz) but may be properly altered as the necessity arises.
Furthermore, when embodying the present invention, the judgment of [YES] in step 360 (see FIG. 12) in the third embodiment may be made based on the relationship of R≧Rmin in stead of R=Rmin. Besides, the judgment in step 650 (see FIG. 16) in the fourth embodiment may be made based on the relationship of R≦Rmax in stead of R=Rmax. | A method for welding together electrically conductive members, comprises detecting step for detecting a removal of an electrically insulating member between a first electrically conductive member and a second electrically conductive member, and welding step for welding together the first electrically conductive member and the second electrically conductive member by an electricity through them to be fixed to each other, after the removal of the electrically insulating member therebetween is detected. | 1 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to generation of electrical power, and more particularly to trailer mounted, mobile systems for generation of electrical power.
2. Description of the Related Art
Mobile power generation systems capable of delivering several or more megawatts of power have been known to offer certain advantages compared to power delivered from the electrical power or utility distribution grid. The mobile power generation systems can provide power as needed at times of peak demand or of brownout in the distribution grid, or in cases of need because of some emergency or other problem in the distribution grid as a result of a power grid failure or some other type of disaster. The mobile power generation systems also can be located at places distant from the distribution network where there is a need for power. There is then no need for the delay or expense of arranging for or construction of power lines to the distant or remote places.
Some years ago, there were attempts made to provide electric power in trailer mounted generator systems. An example of such a trailer mounted generator system is described in a magazine article entitled “Megawatts on Wheels” written by C. F. Thompson, C. R. Boland and E. Bernstein in the March 1971 issue of Combustion, pages 24-30. For some reason, these types of generator systems did not, so far as is known, achieve any extended years of use and were not widely adopted.
As noted above, mobile power generation systems have certain desirable features and advantages. They have again recently become the subject of interest. However, there are a number of intervening factors which give rise to problems with these earlier types of trailer mounted generator systems.
For optimum use, such a system needs to comply with weight and height restrictions from relevant highway regulatory and governmental agencies. Also, there are environmental limitations on the type and acceptable concentration levels of combustion waste products produced by this equipment. In addition, noise from the various components of the generator systems must be kept within presently established regulatory limits.
There were competing considerations regarding mobile power generation systems of this type. On the one hand, limits on weight and size of the systems had to be observed if the systems were to be highway transportable and thus available for widespread use. In conflict with this were the environmental and noise abatement considerations. Further, mobile power generation systems should be self-supporting in that they could bring to the site all equipment necessary to assemble the system in a relatively few days without the need for other equipment such as cranes, hoists and the like. It was felt by at least some that achieving suitable limits on combustion gas product emissions and noise levels could not be achieved while complying with height and weight limits for highway travel.
SUMMARY OF THE INVENTION
Briefly, the present invention provides a new and improved mobile, trailer-mounted power generation system. A gas generator burning a hydrocarbon fuel for creation of combustion gases is operably interconnected with a free turbine which receives combustion gases and rotates a turbine shaft in response thereto. An electrical generator is mounted in communication with the free turbine for the generation of electricity upon rotation of the turbine shaft. A trailer body which is towable by a conventional tractor or truck is provided having a floor on which the gas generator, free turbine and electrical generator are mounted. The trailer body has end and side walls and a roof enclosing the gas generator, free turbine and electrical generator.
The trailer body is provided with an air inlet near one end for passage of air to the gas generator, and the free turbine has an exhaust for exit of the combustion gases. The trailer body has a combustion gas outlet formed in a side wall thereof for exit of the combustion gases from the free turbine. The gas generator, free turbine and electrical generator each have a longitudinal axis about which certain of their power generating components rotate during their operation. The longitudinal axes of the gas generator, free turbine and electrical generator are longitudinally aligned along a common axis along the longitudinal extent of the floor of the trailer body.
With the present invention, the mobile, trailer-mounted power generation system is easily connectable to other road transportable units which provide for removal of undesirable components of the combustion gases without increasing the height or width of the trailer body of the power generation system. The mobile, trailer-mounted power generation system permits modularization of components to achieve generation of electrical power from a road transportable unit while complying with height and weight limits for highway travel and also meeting both noise and environmental requirements.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a plan view of a mobile, trailer-mounted electrical power generation system according to the present invention deployed with a number of support trailers at a power generation site.
FIG. 2 is an isometric view of the mobile, trailer-mounted electrical power generation system of FIG. 1 .
FIG. 3 is a schematic representation in plan view of the interrelation of several components within the power generation system shown in FIGS. 1 and 2.
FIG. 4 is plan view of an alternate deployment to that of FIG. 1 of a mobile, trailer-mounted electrical power generation system according to the present invention at a power generation site.
FIG. 5 is an isometric view of another embodiment of a mobile, trailer-mounted electrical power generation system of the present invention.
FIG. 6 is a schematic representation in plan view of the mobile, trailer-mounted electrical power generation system of FIG. 5 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring first to FIG. 1, there is shown in plan view an exemplary mobile power production installation 10 that has been established at a desired power generation site, either remote or in connection with an established power generation network or grid in order to provide electrical power. The exemplary installation 10 includes several trailer systems 12 , 14 , 16 , 18 , 19 and 20 , each in the form of an enclosed trailer. At the power generation or deployment site, the trailers are supported on jacks in appropriate level positions. Access to the interior of trailers 12 , 14 and 20 through conventional, lockable doors is provided by as set of steps S, ladders or the like.
Trailer system 12 is a mobile power generation system according to the present invention to be described in further detail below. Trailer 12 is a size compatible with applicable highway transport regulations, 10 ft., 6 in. in width, 13 ft., 6 in. in height and 55 ft. long for road travel. Trailer 14 is a controls trailer that houses controls used to monitor and control the operation of the power generation equipment within the trailer 12 . Trailers 16 , 18 and 19 enclose equipment that is used to remove undesirable emissions from the combustion gases formed by the components of trailer 12 , such as NOx, CO and the like. In the preferred embodiment, this is accomplished through the use of selective catalytic reduction (“SCR”) of the emissions.
Trailer 16 contains an injection chamber where treating chemicals are injected into the stream of exhaust combustion gases entering from trailer 12 . Trailer 18 contains a mixing chamber where the exhaust combustion gases and injected chemicals enter and are thoroughly mixed. Trailer 19 contains a reaction chamber where the mixed products enter from the mixing chamber in trailer 18 and are contacted by reduction catalysts suitably disposed to contact the entering gas mixture and react with the indesirable combustion gas products. An outlet is provided in the reaction chamber trailer 19 for venting of the treated exhaust gases to the atmosphere. The SCR techniques may, for example, be those according to U.S. Pat. Nos. 5,601,792 and 5,431,893, which are incorporated herein by reference. Trailer 20 is used to store chemicals and other supplies and to house mixing tanks for forming the urea solution injected into trailer 16 in the SCR process to clean the combustion gas emission stream from trailer 12 .
FIG. 2 illustrates an exemplary mobile power generator system trailer 12 with trailer having a floor 22 , end walls 23 and 25 , side walls 27 and 29 and a roof 31 . Walls 23 , 25 , 27 and 29 and roof 31 are shown in phantom so that the power generating components of the trailer 12 may more clearly be seen. FIG. 3 illustrates certain components of the system of FIG. 2 schematically to illustrate their functional interconnection more clearly. It is noted that the generator system trailer 12 forms a complete and essentially closed system for the generation of electrical power.
The power generator system trailer 12 includes a gas generator 24 operably interconnected with a power generation turbine, or “free” turbine, 26 to supply combustion exhaust gases to the free turbine 26 . The gas generator 24 preferably comprises a Pratt & Whitney FT-4 gas generation unit positioned lengthwise on the trailer 12 along a common longitudinal axis L of rotation of the rotating power generation components of the gas generator 24 and free turbine 26 mounted on the trailer floor 22 . The FT-4 of gas generator 22 is a relatively lightweight aircraft gas turbine which receives fuel (either natural gas or liquid fuel such as jet fuel or diesel) from a conventional storage tank or other source of supply (not shown). The gas generator 22 burns the fuel provided it to form exhaust combustion gases which are furnished to the free turbine 26 through an enclosed cylindrical hood or gas passage. The cylindrical passage or duct for the combustion exhaust gases from the gas generator 24 extends between the outlet of gas generator 24 rearward of its guide vanes to an inlet of the free turbine 26 forward of its nozzle guide vanes. In the embodiment of FIGS. 1-3, the free turbine is Model FT-4 gas turbine originally made by Pratt and Whitney Aircraft and available from various sources. In the embodiment of FIGS. 5 and 6, the free turbine is a “Zorya” PA gas turbine, Model UGT-2500 available through ZDRYA Power (USA) of Annapolis, Md.
The power generation turbine 26 is known as a “free” turbine because the shaft of the turbine 26 is not mechanically interconnected with a shaft within the gas generator 24 . Thus, the turbine 26 is powered by the exhaust combustion gases formed by the gas generator 24 . The free turbine 26 includes a shaft supported by a front and a rear bearing 30 , 32 (see FIG. 3) and having turbine blades mounted therewith to develop rotational movement in response to receipt of the gases from gas generator 24 . The free turbine 26 also has an output shaft 34 that is operably interconnected with an electrical generator 36 . The generator 36 is capable of converting the rotational energy of the output shaft 34 into electrical power. A suitable device for use as the electrical generator 36 is a Peebles 3-phase, 13,800 KVA brushless, air-cooled 25 MW generator. It will be understood that the generator 36 is operably interconnected in a cabinet C with power cables or other electrical transmission means for the supply of electrical power created by the generator 36 .
The transport trailer 22 also supports a gas generator air intake through which external air is supplied to provide a combustion mix in the gas generator 24 with the fuel supplied it. A free turbine oil cooler intake is likewise mounted upon the trailer 22 when the system 12 is set up for power generation. A gas turbine lubrication system 42 is operably interconnected with the gas generator 24 to supply lubricant thereto, while a free turbine lubrication system 44 is operably interconnected with the free turbine 26 in order to supply lubricant to the free turbine 26 .
A L-shaped exhaust elbow 46 is disposed between the free turbine 26 and the electrical generator 36 so that exhaust gases exiting from the free turbine 26 are diverted away from the generator 36 for processing. FIG. 1 illustrates the elbow 46 interconnected with a cylindrical outlet port 48 that is, in turn, secured in sealing engagement with an inlet port 50 to the injection chamber trailer 16 . As has been set forth, the injection chamber trailer 16 , mixing chamber trailer 18 and reaction chamber trailer 19 receive the effluent combustion gases from the power generator trailer 12 so that the exhaust combustion gases may be treated to reduce undesirable emissions such as NOx, CO and the like to environmentally acceptable levels.
The exhaust elbow 46 is in the form of a generally L-shaped outwardly expanding tubular member connected at the outlet of the free turbine 26 to receive exhaust combustion gases and divert and convey these gases from their original axis of travel along the longitudinal axis L of flow through the gas generator 24 and free turbine 26 at a laterally outwardly extending angle A, preferably perpendicularly at an angle of 90° to the longitudinal axis L. The gases diverted in exhaust elbow 46 exit outwardly through the outlet port 48 formed in one of the side walls 27 or 29 of trailer 12 .
It is to be noted that the exhaust combustion gases from the free turbine 26 and gas generator 24 are vented laterally through a side wall 27 or 29 and not upwardly through the roof 32 of the power generator trailer. This permits connection of the trailer 12 at its own elevation to various configurations of emission treatment equipment, noise abatement equipment and the like. For example, FIG. 4 shows the trailer 12 connected at its outlet port 48 to a modified exhaust gas treatment trailer 116 which can provide a simplified SCR treatment of the type discussed above in the present application. Other structure in FIG. 4 like that of FIGS. 1-3 bears like reference numerals. With prior roof-mounted outlets from the earlier free turbine systems, a crane and other expense would have been required to establish any connection. This would have involved additional expense in equipment and time. Thus the present invention provides a mobile, trailer-mounted power generation system which is road transportable to a deployment site where electrical power generation is required. Further, the trailer 12 meets applicable highway regulatory size limits and is connectable at the power generation site to emission control equipment and noise abatement equipment also mounted in trailers without the need for cranes, booms or other special purpose construction equipment.
Those of skill in the art will recognize that many changes and modifications may be made to the devices and methods of the present invention without departing from the scope and spirit of the invention. Thus, the scope of the invention is limited only by the terms of the claims that follow and their equivalents. | A trailer mounted mobile power generation system provides electrical power at locations where it is needed, either separate from or as a supplement to power from an electrical power distribution grid. A jet engine, a free turbine and an electrical power generator in a single common road transportable trailer. The trailer complies with weight and height limitations imposed by transportation authorities. The jet engine drives the turbine, which in turn drives the electrical power generator. Power levels on the order of 20 megawatts are generated while maintaining noise and combustion product emission levels within presently specified regulatory limits. | 5 |
RELATED PATENT DATA
This is a divisional application of U.S. patent application Ser. No. 11,067,041, filed Feb. 24, 2005, which in turn claims priority to U.S. Provisional Patent Application No. 60/547,485, filed Feb. 25, 2004, all of which are incorporated herein by reference.
TECHNICAL FIELD
The present invention relates to alternators.
BACKGROUND OF THE INVENTION
Alternator design is known in the art. It is a fundamental principle of physics that when a magnet rotates in a wire loop, a current is induced. A magnet has a south pole and a north pole. Assume that the north pole is just passing a top part of the wire loop and the south pole is just passing the bottom part of the loop. When the magnet has rotated through 180 degrees, the south pole will be passing the top part of the loop while the north pole will be passing the bottom part of the loop. This causes the direction of induced current to be reversed. In this way, alternating current is induced in each turn of wire in a stator of an alternator.
In an alternator, a rotor is spun inside a stator. The stator includes multiple windings of wire. A single turn would not induce enough voltage nor carry enough current for typical applications of an alternator. Therefore, a practical alternator has a stator with many turns of wire.
The rotor defines an electromagnet that provides a magnetic field that is spun inside the windings of wire to generate current. A relatively small field current used to define the electromagnet is supplied to the rotor by two small brushes that each ride on separate and continuous slip rings. Field current passes through the brushes into the slip rings into the rotor.
There are typically three separate windings of wire in the stator arranged so that the AC (alternating current) that is generated by each winding is slightly out of phase compared to the other windings. This smoothes the electrical output of the alternator.
A rectifier circuit including diodes is used to convert the AC to DC (direct current). The diodes are arranged so that current from each of the three stator wires is only allowed to pass in one direction, and the three outputs are connected together. A voltage regulator is typically provided to the DC output to keep the output voltage relatively steady. The voltage regulator can be a mechanical or solid state device.
For externally regulated alternators, there are typically four connections on the alternator: the output terminal (often labeled BAT), the ground terminal (often labeled GRD) or ground may be “implied” though the metal mountings of the alternator, the field connection (often labeled F), and separate connections to each of the three poles on the stator (R).
Internally regulated models also have four connections, but the voltage regulator is inside the alternator and constructed of solid-state components. For internally regulated alternators, the connections are: an output terminal (typically labeled BAT), a ground terminal (typically labeled GRD) or ground may be “implied” though the metal mountings of the alternator, and two connections typically labeled 1 and 2. One of these connections is a relatively small wire that is connected to a battery and the other is connected to a charge indicator light.
Brushes that ride against the slip rings of the rotor of an alternator are components that are likely the number one failure mode of an alternator since the brushes wear out over time due to friction. Such brushes are conventionally internal, and are housed inside the housing of an alternator. For conventional alternators, in order to changes brushes, the alternator must be removed from service and substantially disassembled. The brush blocks then have to be removed from inside of a rear shell housing component after the rear shell has been removed from the rest of the alternator.
Certain alternators are known in the art that have removable, externally accessible, brush blocks. However, in these designs, the brushes extend out past the end of the main housing. In these designs, the rear bearings of the alternator are axially inside of the slip rings and the brushes.
Certification of components for aircraft use is a lengthy process. Components used in alternators for aircraft have subtle differences when compared with alternators used in automobiles in view of the different environments in which they are used and more serious consequences of failures in aircraft environments. For example, different brush materials are used for alternators used in aircraft than the material used in automotive alternators.
An aircraft alternator designed to deliver a certain level of amperage cannot simply be used on an airplane designed for a lower amperage alternator. For example, an 80 Amp alternator cannot be used on a 40 Amp airplane even though a regulator will regulate the current down to 40 Amps. The problem is that aircraft wiring is typically geared around the maximum rating of the alternator.
For example, forty years ago, when some of these planes were built, 40 Amp alternators were the biggest alternators available. Therefore, the gauge of the wiring going from the alternator was geared around that rating. If higher amperage current, such as 80 Amps, was passed through, the wiring could burn up. Provided that the regulator is working correctly, this would not happen. However, regulators sometimes fail and fields sometimes short. Safety standards for aircraft dictate that an aircraft alternator cannot be capable of putting out more than the designated current. This means that different alternator designs are used in different aircraft, causing manufacturers to manufacture multiple different types of alternators and causing vendors and repair facilities to stock multiple different types of alternators.
SUMMARY OF THE INVENTION
Embodiments of the invention provide an alternator with a removable brush block. Other embodiments provide an alternator with a replaceable resistor in series with the field.
One aspect of the invention provides a method of changing the maximum current output of an alternator, in view of aircraft safety standards requiring that alternators for aircraft not be able to put out more than a predetermined amperage, notwithstanding the ability to regulate current with a regulator outside of the alternator. Other methods and apparatus are also provided.
BRIEF DESCRIPTION OF THE DRAWINGS
Preferred embodiments of the invention are described below with reference to the following accompanying drawings.
FIG. 1 is a perspective view of an alternator in accordance with various embodiments of the invention.
FIG. 2 is a cut away perspective view of the alternator of FIG. 1 .
FIG. 3 is an exploded perspective view of a housing portion, brush holder, and holder plate, of the alternator of FIGS. 1 and 2 .
FIG. 4 is a view of the brush holder of FIG. 3 , assembled to the holder plate of FIG. 3 , and together removed from the alternator of FIG. 1 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
This disclosure of the invention is submitted in furtherance of the constitutional purposes of the U.S. Patent Laws “to promote the progress of science and useful arts” (Article 1, Section 8).
As mentioned above, brushes that ride against the slip rings of the rotor are perhaps the number one failure mode in alternators. They wear out. Therefore, besides making them as strong and as long lasting as possible, they are made to be easily interchanged.
With standard alternators, and with all or substantially all aviation alternators, in order to change out brushes, substantially the whole alternator has to be disassembled to replace the brushes.
FIG. 1 shows an alternator 10 embodying various aspects of the invention. In the embodiment of FIG. 1 , the alternator 10 is an aircraft alternator. The alternator 10 includes a housing 12 . In the illustrated embodiment, the housing 12 includes a front case portion 14 ( FIG. 2 ), and a rear case portion 16 having a plurality of electrical connectors 60 , 70 , 72 , 74 , 76 , and 78 for inputs and outputs. Connector 60 is a field input. Connector 70 is a power output. Alternator 10 has a mounting end 33 and a free end 35 (see FIG. 2 ). The housing further includes an aperture or material removed portion 20 ( FIG. 3 ).
The alternator 10 includes a stator 22 ( FIG. 2 ) supported in the housing 12 . More particularly, in the illustrated embodiment, the stator 22 is at least partially supported by the front case portion 14 of the housing and the rear case portion 16 can be removed from the front case portion 14 without removing the stator 22 . The alternator 10 further includes a rotor 24 ( FIG. 2 ), including slip rings 26 and 28 , and including a rotor shaft 30 configured to rotate about an axis 32 . The shaft has opposite ends 34 and 36 .
The alternator 10 further includes front and rear bearings 38 and 40 respectively supporting the ends 34 and 36 of the rotor shaft 30 in the housing 12 for rotation relative to the stator 22 .
The alternator 10 further includes a removable assembly 42 ( FIG. 2 ) including a support member or holder plate 44 and a brush holder 46 ( FIG. 3 ). The brush holder 46 includes brush blocks 48 and 50 ( FIG. 2 ) configured to slidingly support brushes 52 and 54 ( FIG. 4 ). The term brush block, as used herein, refers to any structure configured to support a brush. In the illustrated embodiment, the brush blocks 48 and 50 are each defined by a cartridge or chamber that slidingly receives a brush and a spring. More particularly, in the illustrated embodiment, the brushes 52 and 54 are biased by springs in the cartridges 48 and 50 into engagement with the slip rings 26 and 28 . The brushes 52 and 54 are electrically configured to pass a force current through the rotor 24 via the slip rings 26 and 28 . In the illustrated embodiment, the brushes 52 and 54 are each made of a special carbon used for aircraft applications. For example, for aircraft applications, aircraft grade brush material is used for high altitude applications.
The brush holder 46 ( FIGS. 3 and 4 ) is removably supported by the support member 44 . The removable assembly 42 is selectively fixed relative to the rear case portion 16 of the housing against movement relative to the front case portion 14 of the housing when in a “in use” position. When in the “in use” position, the brushes 52 and 54 engage the slip rings 26 and 28 and the support member 44 at least partially closes the aperture or material removed portion 20 ( FIG. 3 ).
The support member 44 has an inside surface 56 ( FIG. 2 ) configured to face inside the housing 12 , when the removable assembly 42 is in the “in use” position, and an outside surface 58 configured to face away from the alternator 10 , when the removable assembly 42 is in the “in use” position. The brush blocks 48 and 50 are mounted to, covered by or positioned by the inside surface 56 . In the illustrated embodiment, the brush holder 46 is mounted to and movable with the support member 44 . The outside surface 58 supports a force terminal 60 which is electrically coupled to one of the brushes 52 , 54 . In the illustrated embodiment, the force terminal 60 is defined by an electrically conductive post extending away from the support member 44 .
In some embodiments, the support member 44 has a surface 62 configured to mate with the material removed portion or aperture 20 to close the aperture 20 when the removable assembly 42 is in the use position. Alternatively, the support member 44 overlaps or covers the aperture 20 either completely or partially.
The slip rings 26 and 28 are located ( FIG. 2 ) between the bearings 38 and 40 with respect to the axis 32 defined by the rotor shaft 30 . More particularly, in the illustrated embodiment, the brushes 52 and 54 ( FIG. 4 ) are internal of the housing 12 and the slip rings 26 and 28 are internal of the housing 12 . Still more particularly, in the illustrated embodiment, the rear bearings 40 are axially outside of the slip rings 26 and 28 , and the slip rings 26 and 28 are on the inside of the housing 12 , yet removable brush blocks 48 and 50 are provided. There are advantages to this design. The farther apart the front bearings 38 are located from the rear bearings 40 , the more stable the rotation will be. Also, this design gives better protection to the slip rings 26 and 28 .
The removable assembly 42 is removable from the rear case portion 16 of the housing 12 from outside the housing 12 (e.g., with a hand tool such as a screwdriver), without the need to remove the rear case portion 16 of the housing 12 from the front case portion of the housing 14 .
In the embodiment of FIG. 1 , to remove the removable assembly 42 and the brush blocks 48 and 50 , a user removes fasteners 64 ( FIG. 3 ) that hold the removable assembly 42 in the housing 12 , from outside the housing 12 , removes the removable assembly 42 , replaces the assembly 42 with a new assembly 42 (or replaces the brushes 52 and 54 within the assembly), and refastens the new or upgraded assembly to the housing 12 . A removable pin 68 ( FIG. 4 ) holds the brushes 52 and 54 in the brush blocks 48 , against the bias of springs in the brush blocks 48 and 50 , until the removable assembly 42 is replaced. After the removable assembly 42 is replaced, the pin 68 is removed from the removable assembly 42 , allowing the brushes 52 and 54 to extend from the brush blocks 48 , 50 into engagement with the respective slip rings 26 , 28 . In the illustrated embodiment, the fasteners 64 are screws; however, other appropriate fasteners could be used.
The field current passes through the brush 52 or 54 into the slip ring 26 or 28 , and into the rotor 24 . That applies power to the rotor 24 , creating the magnetic field of the rotor 24 that causes the generation of energy in the stator 22 .
Typically, alternators are designed such that field current is transmitted generally directly to the rotor. In the illustrated embodiment, the alternator 10 is capable of a predetermined current output. For example, in the illustrated embodiment, the alternator 10 is an aircraft alternator capable of outputting up to about 80 Amps. However, there are aircraft that have different maximum current ratings. For example, some aircraft need 40 Amp alternators, some need 60 Amp alternators, and some need 70 Amp alternators.
Therefore, in some but not all embodiments, the removable assembly 42 further supports a resistor 66 ( FIG. 4 ) configured to reduce current provided to the rotor 24 . More particularly, in the illustrated embodiment, the resistor 66 is easily removable and replaceable. Still more particularly, in the illustrated embodiment, the resistor 66 is removable from the housing 12 with the brush blocks 48 and 50 .
The resistor 66 is placed in-line with the field current. For example, in some embodiments, the resistor 66 is electrically coupled between the force terminal 60 and one of the brushes 52 and 54 . More particularly, the resistor 66 is removably attached to the inside surface 56 of the support member 44 using a pair of screws 80 and 82 . Field current travels from externally of the alternator 10 through the post or terminal 60 , through this resistor 66 , and then to a brush 52 or 54 .
Depending upon the resistance value of the resistor 66 that is used, a different model alternator 10 is created for use on an aircraft that uses a certain ampere alternator. In the illustrated embodiment, the brush blocks 48 , 50 are replaceable with brush blocks supporting resistors 66 that are appropriate to define a 40, 60, or 70 Amp alternator. Alternatively, the resistor 66 could be removed and replaced with a conductor or bypassed with a jumper to define an 80 Amp alternator. In fact, the same alternator 10 could be adapted to any ampere rating (lower than its maximum output) by replacing the resistor 66 . The resistor 66 is on the input or field end of the circuit. By reducing the amount of current going into the alternator 10 , the amount of magnetism produced is reduced by the resistor 66 .
This design saves expense in manufacturing and in stocking of alternators.
In some embodiments, the alternator case or housing used is a Delco™ 10DN case. Alternative housing styles could also be employed.
In compliance with the statute, the invention has been described in language more or less specific as to structural and methodical features. It is to be understood, however, that the invention is not limited to the specific features shown and described, since the means herein disclosed comprise preferred forms of putting the invention into effect. The invention is, therefore, claimed in any of its forms or modifications within the proper scope of the appended claims appropriately interpreted in accordance with the doctrine of equivalents. | An alternator comprises a housing including a first portion, and a second portion having a plurality of electrical connectors and having an aperture; a stator supported in the first portion of the housing; a rotor supported for rotation relative to the stator and configured to have a force current applied thereto; and a resistor coupled to the rotor and configured to reduce the current through the rotor, the resistor being removable and replaceable. Other apparatus and methods are provided. | 7 |
BACKGROUND OF THE INVENTION
The invention has as its object a sewing machine, comprising elements for lateral control and positioning of the needle holder bar and for the adjustment of the amplitude and the direction of the movement of the material to be sewn.
A sewing machine is known such as in Swiss Pat. No. 277,952 in which the lateral movements of the needle holder bar and the advance of the feed are controlled by two cams, fastened in a removable way on a drive shaft, in continuous movement, that can be replaced by other interchangeable cams.
By the present invention, an improved arrangement is presented wherein separate, multi-faced cams each controlled by an individual servomotor are located in the machine upper and lower frames and are regulated by suitable control means such as one or more microprocessors to respectively manipulate the lateral needle bar movement and feed dog movement. Additionally, the upper frame cam serves to immobilize the needle bar. In this manner, the two permanently installed cams may be operated in a plurality of coordinated modes to achieve numerous stitching patterns without the necessity of exchanging cam elements as in many prior known machines.
SUMMARY OF THE INVENTION
To automate, simplify and increase the sewing capabilities, the machine according to the invention is characterized in that, on the one hand, it comprises a first servomotor that drives at least two cam portions, or faces, the first face making it possible, by contact with a first feeler, to assure the lateral positioning of the needle holder bar, and the second face working with the first face against which a third feeler rests to assure the disengaging of the needle bar, while a second servomotor drives at least a cam face that determines, by contact with a fourth feeler, the amplitude of the forward movement or the backward movement of the material to be sewn.
BRIEF DESCRIPTION OF THE DRAWINGS
The accompanying drawings diagrammatically and by way of example show an embodiment of the machine according to the invention.
FIG. 1 is a partial view, showing the upper arm of the machine in front elevation with cutaways.
FIG. 2 is a partial view of it, showing the head of the machine in section along II--II of FIG. 1.
FIG. 3 is a view in larger scale, partially in axial section, of the needle bar, shown in FIG. 2.
FIG. 4 is a view similar to FIG. 3, showing the needle bar in the disengaged position.
FIG. 5 is a view in perspective of the control cam, shown in FIGS. 1 and 2.
FIG. 6 is a diagram of the functions of the cam, shown in FIG. 5.
FIG. 7 shows a variant of the disengaging element of the needle bar.
FIG. 8 is a partial top view with cutaway of the lower frame of the machine.
FIG. 9 is a view in cross section along IX--IX of FIG. 8.
FIG. 10 is a view in cross section along X--X of FIG. 8.
FIG. 11 is a view in cross section along XI--XI of FIG. 8.
FIG. 12 is a view in cross section along XII--XII of FIG. 8.
FIG. 13 is an exploded view, seen from right to left, of FIG. 12.
FIG. 14 is a view in section of it along XIV--XIV of FIG. 8.
FIG. 15 is a view in section along XV--XV of FIG. 14.
FIG. 16 is a diagram of the functions of the control cam, shown in FIGS. 8 and 9.
DESCRIPTION OF THE PREFERRED EMBODIMENT
As shown in FIGS. 1 and 2 of the drawings, the sewing machine comprises an upper arm or frame U with a tubular needle bar 1, mounted to slide in a swivelling cradle 2, the longitudinal reciprocating movement of needle bar 1 being assured by a journal 3, connected to a connecting rod 4 and driven by an eccentric plate 5 mounted on main drive shaft 12 of the machine.
As shown in FIGS. 5 and 6, a first cam 29 comprises two laterally presented faces B and C for controlling zig-zag sewing. To do this, cam 29 is subjected to an alternating oscillating movement of determined amplitude by a first servomotor 28 as depicted in FIGS. 1 and 2. In straight sewing, the lateral positioning of a needle N attached to needle bar 1 is also controlled by the angular position of cam 29, determined by servomotor 28. This automatic control makes it possible to obtain infinite variations of the width of the stitch, or of the lateral positioning of the needle bar.
As shown in FIGS. 2 and 6, the control of the crosswise movement of needle bar 1 is assured by face C of cam 29, against which a feeler 37 solid with the upper end of cradle 2 rests. Cam face B is engaged by another feeler 39 mounted on a lever arm 38 in turn mounted to pivot on oscillation shaft 6 of cradle 2. Feelers 37 and 39 are kept in contact with cam faces B, C by a counterspring 40.
As shown in FIGS. 3 and 4, a control element 26 for disengaging needle bar 1 is mounted to pivot on a transverse shaft 24 inside the tubular needle bar 1. A rod 18 inside the bar 1 exhibits a ramp 22, which, when it is inserted, against the action of a return spring 25, between the inner wall of needle bar 1 and the head 23 of the pivotal control element 26, causes it to pivot on shaft 24. Because of this, plug 17 of control element 26 pushes lug 9 outside of an opening 11 in the bar 1, against the action of spring 10. Consequently, journal 3 slides on needle bar 1, which remains in high position under the action of a spring, with a needle bar locking ring 13 being held by a stop S.
As shown in FIGS. 5 and 6, cam 29 comprises a third face or ramp A 1 , A 2 , A 3 , against which a feeler 30 of a lever 31 rests. The feeler is hinged on a shaft as at 21 in FIG. 2.
When servomotor 28 drives cam 29, shown in FIG. 2, in a clockwise direction, feeler 30 resting on the ramp at A 1 will go on to A 3 and pivoting lever 31 will urge the attached support element 32 into position for disengaging needle bar 1. This action occurs as the element 32 abuts the opposite free end of disengaging rod 18 being driven during the lifting of needle bar 1.
The stop S for holding locking ring 13 can be advantageously replaced by support element 32, provided that the upper end of rod 18 (FIG. 7) exhibits a clearance 20, making it possible for support element 32 to hold needle bar 1 in engaged position, when feeler 30 rests against position A 2 of the third cam face.
The lateral position of needle bar 1 remains determined by the displacement of the feeler 37 by the cam faces B and C, as feeler 30 engages the third cam face portions A 2 or A 3 . With the above description in mind, it will be seen that FIG. 6 depicts the lateral displacement of various points along the cam faces B and C relative to the radial displacement of points along the faces A 1 , A 2 and A 3 during each revolution of cam 29 as reflected by the line D-E.
With additional faces, cam 29 could further assure other functions such as the adjustment of the tension of the thread, for example (not shown).
Quite obviously, the production of varied zig-zag stitching patterns requires a direct coordination between not only the lateral displacement of the needle bar but also the feed rate of the fabric being operated upon. With this in mind, it should be fully appreciated that the control of the movement of the machine feed dog 47 with respect to the needle bar operation, is quite important. In this regard, the present invention includes the provision of a second cam regulated by a second servomotor within the machine lower frame L together with appropriate displaceable means for regulating the movement of the associated feed dog.
As shown in FIGS. 8 to 12 another or second cam 83 within the lower frame or bed L is positioned angularly by another or second servomotor 70 to control the amplitude of the forward movement and backward movement of feed dog 47 integral with a feed dog support 46. This action is controlled by a feeler 63, solid with a lever 64 and in contact with face 62 of cam 83, this control being transmitted by lever 64, hinged to the frame. The resultant displacement is determined by links 65 and 66 and the angular position of a link 61, it being understood that links 66 and 61 are solid with the same shaft 67, hinged in the frame. The angular position of link 61 determines the direction and the amplitude of the movement of feed dog support 46 by way of links 57, 52, this latter being connected by a shaft 54 to an angular link 55, 56. The common shaft 53 of links 57, 52 is driven by an eccentric 50 and a connecting rod 51.
As shown in FIG. 9, a lever 94 connected to the frame is equipped with a feeler 95 in contact with a cam 83 with a face 97, parallel to a face 62 and assures the contact of feeler 63 against face 62, under the action of a return spring 96 connecting lever 64 to lever 94, thus forming a parallelogram, constituting a device for taking up the play with an approximately constant torque.
As shown in FIGS. 8, 14 and 15, a second face 93 of cam 83 controls by a lever 85 the angular position of a part 87, hinged in a bearing 92 of the frame and angularly orients a plane or surface 88, solid with part 87, in relation to the standard sewing direction of feed dog 47, so as to produce a lateral movement of feed dog support 46, against the action of a return spring. This is due to the oscillation produced by eccentric 89 upon the fork 69 swivelling on a shaft 68. The fork 69 will be seen to include balls 86 placed between feed dog support 46 and plane 88.
Depending on the orientation of plane 88, the lateral movement of feed dog support 46 is performed perpendicularly to the standard sewing direction in one direction or the other (left or right, see FIG. 8).
Alternately, plane 88 could oscillate with part 87 in bearing 92 of the frame by an eccentric, the amplitude and the direction of lateral movement of feed dog support 46 being determined by the position of balls 86 along plane 88.
As shown in FIGS. 12 and 13, feed dog support 46 rests on a ball-and-socket support connecting rod 45, to allow both lengthwise and crosswise movement or simultaneous lengthwise and crosswise movement of feed dog support 46.
As shown in FIGS. 8 and 12, an eccentric cam 41 solid with lower shaft 42 of the machine drives a lever 43 hinged on a shaft 44, solid with the lower frame, to assure the lifting of the feed dog support 46 by ball-and-socket support connecting rod 45. By moving lever 43 to the left of FIG. 8, on shaft 44 by manual pusher or selector 49, lever 43 comes to rest on a cylindrical element 48. An interruption of the feeding of the fabric by feed dog 47 results because there is no longer a lifting of the feed dog, this feed dog remaining below the sewing plane, as a result of the retraction of the ball-and-socket support connecting rod 45 (see FIG. 13).
The movement of lever 43 for putting feed dog 47 in or out of operation could be assured by an additional face of cam 83.
Several functions which can be assured by faces 62 and 93 of cam 83 have been diagrammatically represented, from left to right in FIG. 16, that can be made by the combination of the two directions of feed of the fabric, in relation to one another.
F 1 corresponds to the adjustment of the amplitude of the length of the stitch during the feed in reverse from 0 to the maximum M 1 , face 93 of cam 83 keeping plane 88 parallel to the standard sewing direction.
F 2 corresponds to the forward movement adjustment of the length of stitch O at the maximum M 2 , face 93 of cam 83 keeping plane 88 parallel to the standard sewing direction.
F 3 corresponds to a movement on the bias of forward movement sewing with variable stitch length combined with a lateral movement to the left with intervention of lever 85, driven by face 93 or cam 83.
F 4 corresponds to a forward-reverse fine adjustment zone, the slope of face 62 of cam 83 being reduced to make possible a more precise adjustment of small stitch lengths, for the same oscillation angle of cam 83 as in F 1 and F 2 . This mode would apply for example, for the sewing of bourdon stitches, button holes, etc., with face 93 of cam 83 keeping plane 88 parallel to the standard sewing direction.
F 5 corresponds to a combination of forward-reverse and left-right feed, determined by face 62 of cam 83, working with lever 85, by contact with face 93 of cam 83, thus making possible the following combinations:
a: reverse feed+lateral feed to the right
b: no feed
c: forward feed+lateral feed to the left
d: forward feed only
e: foward feed+lateral feed to the right
f: lateral feed to the right only
g: reverse feed only
h: reverse feed+lateral feed to the left
i: lateral feed to the left only
Consequently, depending on the angular position of cam 83, it is possible to make tack, linear, and multidirectional stitching.
F 6 corresponds to the adjustment of the amplitude of the lateral feed of a maximum M 3 to the right to a maximum M 4 to the left while passing by a position corresponding to a zero feed.
The synchronization of the various control elements is assured between main drive shaft 12 and a lower shaft 42 by belt 90 and under the control of a servodisk 91, mounted on one of these shafts. The servomotors can be managed by one or more microprocessors. | The lateral displacement or oscillation of a sewing machine needle bar is controlled by a permanently installed servomotor-driven cam operated in coordination with a second similarly installed servomotor-driven cam controlling the displacement of the fabric feed dog. Manipulation of the faces on the two cams, in a synchronized manner, allows numerous stitch patterns to be achieved according to the amplitude and direction of displacement of the needle bar and feed dog pursuant to the positioning of the faces on the two cams by their respective servomotors. | 3 |
[0001] This application claims the benefit of Taiwan application Serial No. 93110140, filed Apr. 12, 2004, the subject matter of which is incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The invention relates in general to an electronic device, and more particularly to a foldable electronic device.
[0004] 2. Description of the Related Art
[0005] With the rapid development in science and technology in recent years, the size of electronic device has the tendency of miniaturization. A foldable cellar phone which is handy and portable can be said to be the typical one of foldable electronic devices.
[0006] Referring to FIG. 1A , an arrangement of a stopper in a conventional foldable electronic device is shown. A foldable electronic device 100 includes a main body 102 , a flip cover 104 and a rotation device 106 . The flip cover 104 and main body 102 are pivotally connected together via the rotation device 106 . That is, the flip cover 104 can rotate against the main body 102 by means of the rotation device 106 . The maximum flip angle that the flip cover 104 can rotate against the main body 102 is determined according to how the pair of stoppers 108 a and 108 b , disposed on one side of the main body 102 , protrude from the main body 102 .
[0007] Please refer to both FIG. 1B and FIG. 1C . FIG. 1B is a diagram showing the status when the stopper 108 b of a conventional foldable electronic device protrudes from the main body, while FIG. 1C is a diagram showing another status when the stopper 110 of a conventional foldable electronic device protrudes from the main body.
[0008] The flip cover 104 rotates and flips against the main body 102 via the rotation device 106 . When the stopper 108 b or the stopper 110 stops the movement of the flip cover 104 , the flip cover 104 will stop at a maximum flip angle.
[0009] As shown in FIG. 1B and FIG. 1C , the difference between the stopper 108 b and the stopper 110 lies in the external design of protruding from the main body 102 , so the maximum flip angle that the flip cover 104 could flip will differ accordingly.
[0010] Since the stopper 110 is different in external design, the maximum flip angle θ 1 of the flip cover 104 as shown in FIG. 1B will be larger than the maximum flip angle θ 2 of the flip cover 104 as shown in FIG. 1C .
[0011] Referring to FIG. 2 , another arrangement of the stopper of the conventional foldable electronic device is shown. Foldable cellar phone 200 includes a main body 202 , a flip cover 204 and a rotation device 206 . The flip cover 204 and main body 202 are coupled together via the rotation device 206 .
[0012] A pair of stopper 208 a and 208 b of the foldable electronic device 200 are disposed on one side of the flip cover 204 , and are different from the position on which stopper 108 a and 108 b of the foldable electronic device 100 of FIG. 1A are disposed on the main body 102 .
[0013] When the flip cover 204 rotates and flips against the main body 202 , the stoppers 208 a , 208 b disposed on one side of the flip cover 204 can stop the movement of the flip cover 204 , so the flip cover 204 can be positioned at a predetermined maximum flip angle. The magnitude of the maximum flip angle is determined according to how the pair of stoppers 208 a and 208 b protrude from the flip cover 204 .
[0014] In the above-mentioned conventional foldable electronic devices, the maximum flip angle of the flip cover is determined by where the stopper is arranged, i.e., disposed on the main body or the flip cover.
[0015] Consequently, the maximum flip angle that the flip cover rotates against the main body will be restricted by the external design of the stopper. Moreover, after a long term operation, collision between the flip cover and the main body makes the flip cover or the main body peels its coating off easily, noise is also generated.
SUMMARY OF THE INVENTION
[0016] It is therefore an object of the invention to provide a foldable electronic device. The flip angle of the foldable electronic device of the invention not restricted by the external arrangement of the stopper of the foldable electronic device when the flip cover rotates and flips against the main body. Moreover, the flip cover or the main body of the foldable electronic device will not easily peel off its coating when the flip cover flips against the main body. There will be free of noise even when collision occurs between the flip cover and the main body.
[0017] The invention achieves the above-identified object by providing a foldable electronic device having a first housing, a first protruding portion, a second housing, a second protruding portion and a pivotal connection. The first housing has a first hinge part on which a first protruding portion is disposed. The second housing has a second hinge part, and the second housing can rotate against the first housing via the pivotal connection between the second hinge part and the first hinge part. The second protruding portion is disposed on the second hinge part and corresponds to the first protruding portion of the first hinge part. When the second housing rotates against the first housing, the first protruding portion of the first hinge part stops the movement of the second protruding portion of the two hinge parts for the second housing to be positioned at a flip angle.
[0018] In the foldable electronic device of the above invention, the first protruding portion, the first hinge part and the first housing can be a formed-in-one-block structure. While the second protruding portion, the second hinge part and the second housing can be a formed-in-one-block structure as well.
[0019] Besides, in the foldable electronic device of the above invention, the first hinge part can have a shaft on which the first protruding portion is disposed, while the second hinge part can have an axle hole on which the second protruding portion is disposed. The second hinge part and the first hinge part are pivotally connected via the matching of the axle hole and the shaft, and the second housing can rotate against the first housing around the shaft.
[0020] Moreover, in the foldable electronic device of the above invention, the flip angle is determined according to the position of the first protruding portion as disposed on the shaft, and the position of the second protruding portion as disposed inside the axle hole. On the other hand, a third protruding portion can be disposed inside the axle hole, the axle hole and shaft can be closely jointed via the third protruding portion for the second housing to rotate against the first housing.
[0021] According to another object of the invention, a pivotal joint including a first hinge part, a first protruding portion, a second hinge part and a second protruding portion is provided. The first hinge part has a shaft on which a first protruding portion is disposed. The second hinge part has an axle hole on which a second protruding portion is disposed. Via the pivotal connection between the axle hole and the above shaft, the second hinge part can rotate against the hinge part. When the second hinge part rotates against the hinge part to a maximum predetermined angle, the first protruding portion on the shaft can stop the second protruding portion inside the axle hole. Therefore, the first hinge part and the second hinge part are relatively stopped and positioned.
[0022] Other objects, features, and advantages of the invention will become apparent from the following detailed description of the preferred but non-limiting embodiments. The following description is made with reference to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0023] FIG. 1A is a diagram of the stopper arrangement of a conventional foldable electronic device;
[0024] FIG. 1B is a diagram showing the rotation of the flip cover is ultimately stopped by the stopper located on the main body of a conventional foldable electronic device;
[0025] FIG. 1C is a diagram showing a smaller maximum opening angle of the flip cover due to different external design of the stopper;
[0026] FIG. 2 is another diagram of the stopper disposed in the flip cover of a conventional foldable electronic device;
[0027] FIG. 3A is a decomposition diagram of the pivotal joint of the foldable electronic device according to a preferred embodiment of the invention;
[0028] FIG. 3B is the decomposition diagram of the pivotal joint in another angle according to a preferred embodiment of the invention;
[0029] FIG. 4 is a partial diagram of the main body of the foldable electronic device according to a preferred embodiment of the invention;
[0030] FIG. 5 is a partial diagram of the flip cover of the foldable electronic device according to a preferred embodiment of the invention;
[0031] FIG. 6 is a partial cross-sectional view of the foldable electronic device according to a preferred embodiment of the invention; and
[0032] FIG. 7 is a partial cross-sectional view of another foldable electronic device according to a preferred embodiment of the invention.
DETAILED DESCRIPTION OF THE INVENTION
[0033] Referring to FIG. 3A , a decomposition diagram of the pivotal joint of the foldable electronic device according to a preferred embodiment of the invention is shown. The foldable electronic device 300 includes a first housing, a pivotal joint 301 and a second housing. For the purpose of illustration, the first housing in the present preferred embodiment can be, for example, a main body 302 , while the second housing can, for example, be a flip cover 304 . However, the scope of protection is not limited thereto. Moreover, the foldable electronic device 300 of the present preferred embodiment can be a communication device such as a notebook computer or a personal digital assistant (PDA).
[0034] The pivotal joint 301 includes a first hinge part 306 and a second hinge part 312 . The first hinge part 306 is disposed on the main body 302 , while the second hinge part 312 is disposed on the flip cover 304 . The first protruding portion 310 is disposed on the first hinge part 306 of the main body 302 . The second protruding portion 316 is disposed on the second hinge part 312 of the flip cover 304 , while the second protruding portion 316 corresponds to the first protruding portion 310 of the first hinge part 306 .
[0035] Via the pivotal joint 301 formed by the first hinge part 306 and the second hinge part 312 , the flip cover 304 can rotate against the main body 302 . When the flip cover 304 rotates against the main body 302 , the first protruding portion 310 of the first hinge part 306 can stop the movement of the second protruding portion 316 of the second hinge part 312 and thus stop the flip cover 304 at a maximum flip angle a (not shown in the diagram). That is, the second protruding portion 316 has the same effect as the stopper and positioning device.
[0036] Referring to FIG. 3B , the pivotal joint in another angle of the foldable electronic device according to a preferred embodiment of the invention is shown. In practice, as shown in FIG. 3B , the first hinge part 306 and the second hinge part 312 are respectively disposed and pivotally jointed to make the flip cover 304 rotate against the main body 302 .
[0037] To clearly understand the pivotal connection between the main body 302 and the flip cover 304 as well as the position after the flip cover 304 rotates against the main body 302 , please refer to FIG. 4 and FIG. 5 . FIG. 4 is a partial diagram of the main body of the foldable electronic device according to a preferred embodiment of the invention, while FIG. 5 is a partial diagram of the flip cover of the foldable electronic device according to a preferred embodiment of the invention.
[0038] In FIG. 4 , the shaft 308 with steps is disposed inside the first hinge part 306 of the main body 302 , while the first protruding portion 310 is disposed on the shaft 308 . In a preferred practice, the first protruding portion 310 can be a cylinder.
[0039] In FIG. 5 , the second hinge part 312 of the flip cover 304 has an axle hole 314 corresponding to the shaft 308 of FIG. 4 . The diameter of the axle hole 314 is slightly larger than the outer diameter of the shaft 308 , so the first hinge part 306 can be cupped into the axle hole 314 of the second hinge part 312 via the shaft 308 to form a pivotal joint 301 by the first hinge part 306 and the second hinge part 312 . Via the pivotal connection between the axle hole 314 and the shaft 308 , the first hinge part 306 can rotate against the second hinge part 312 to make the flip cover 304 rotate against the main body 302 .
[0040] Besides, the second protruding portion 316 is disposed inside the axle hole 314 . The second protruding portion 316 serves as a stopper to stop the first protruding portion 310 . That is, when the second hinge part 312 rotates against the first hinge part 306 to a maximum predetermined angle, the first protruding portion 310 is stopped rotating by the second protruding portion 316 . That is, the flip cover 304 will stop rotation and will be positioned to a maximum flip angle a relative to the main body 302 (as shown in FIG. 6 ).
[0041] Moreover, the maximum predetermined angle that the second hinge part 312 rotates against the first hinge part 306 is determined according to the relative position between the first protruding portion 310 disposed on the shaft 308 and the second protruding portion 316 disposed inside the axle hole 314 . For example, if the first protruding portion 310 is disposed on the shaft 308 with an increase of 5 degrees of angular displacement away from the second protruding portion 316 , while the position of the second protruding portion 316 as disposed inside the axle hole 314 remains unchanged, the second hinge part 312 can rotate 5 more degrees against the first hinge part 306 . Consequently, the maximum flip angle a that the flip cover 304 can rotate against the main body 302 can increase an angular displacement of 5 degrees.
[0042] Relatively, if the second protruding portion 316 is disposed on the lateral side of the axle hole 314 with an increase of 5 degrees of angular displacement away from the first protruding portion 310 , while the position of the first protruding portion 310 as disposed on the shaft 308 remains unchanged, the maximum flip angle a between the main body 302 and the flip cover 304 will increase by 5 degrees. Therefore, the positioning mechanism of the invention can precisely control the required angle for the flip cover 304 to be flipped and positioned.
[0043] Referring to FIG. 6 , a partial cross-sectional view of the foldable electronic device according to a preferred embodiment of the invention is shown. When rotating against the main body 302 , the flip cover 304 will be relatively positioned to a maximum flip angle a by the main body 302 because the movement of the second protruding portion 316 disposed on the flip cover 304 is stopped by the first protruding portion 310 disposed inside the main body 302 .
[0044] Referring to FIG. 7 , a partial cross-sectional view of a foldable electronic device according to another preferred embodiment of the invention is shown. The foldable electronic device 700 according to the present preferred embodiment differs from the prior preferred embodiment in that a first protruding portion 702 and a second protruding portion 704 are disposed on different positions. Moreover, the foldable electronic device 700 according to the present preferred embodiment further includes a third protruding portion 706 . The third protruding portion 706 is disposed on a lateral wall of the axle hole 314 . With the additional third protruding portion 706 , the axle hole 314 can be even closely cupped with the shaft 308 for the second hinge part 312 to rotate against the first hinge part 306 even firmly. In other words, the flip cover 304 can rotate against the main body 302 even firmly.
[0045] The change the disposition of the first protruding portion 702 or the second protruding portion 704 will adjust the maximum flip angle. The maximum flip angle β, as shown in FIG. 7 , is larger than the maximum flip angle a as shown in FIG. 6 .
[0046] In order to reduce the cost of mold production, the first protruding portion 310 , the shaft 308 , the first hinge part 306 and the main body 302 can be formed in one block. Since the external design and position of the first protruding portion 310 could be formed by the mold before mold injection, no extra cost will be required for the first protruding portion 310 to be embedded into the shaft 308 . Similarly, the second protruding portion 316 , the second hinge part 312 and the flip cover 304 can be manufactured using a formed-in-one-block structure.
[0047] The foldable electronic device of the invention uses the first protruding portion and the second protruding portion respectively disposed inside the main body and the flip cover to serve as stoppers when the flip cover rotates and flips against the main body. The maximum flip angle of the foldable electronic device can be therefore precisely controlled and is not restricted by the external design of the main body and the flip cover. On the other hand, the foldable electronic device of the invention can solve the collision problem between the foldable electronic device flip cover and main body, preventing the flip cover and the main body from peeling or cracking due to collision, which usually occurs in the conventional foldable electronic device. Moreover, the first protruding portion and the second protruding portion respectively disposed inside the flip cover and the main body can effectively reduce the noise caused by the fraction therebetween, because the flip cover is stopped and positioned inside the foldable electronic device and the noise generated can be effectively contained within.
[0048] While the invention has been described by way of example and in terms of a preferred embodiment, it is to be understood that the invention is not limited thereto. On the contrary, it is intended to cover various modifications and similar arrangements and procedures, and the scope of the appended claims therefore should be accorded the broadest interpretation so as to encompass all such modifications and similar arrangements and procedures. | A foldable cellular phone includes a first housing, a first protruding portion, a second housing, and a second protruding portion. The first housing includes a first hinge part, the first protruding portion being disposed on the first hinge part. The second housing includes a second hinge part, the second protruding portion being disposed in the second hinge part. The first hinge part and the second hinge part couple with each other as a hinge. When the second housing rotates around the hinge relatively to the first housing, the second protruding portion corresponding to the first protruding portion is capable of acting as a stopper to stop the movement of the first protruding portion. Subsequently, the second housing is in a flip position with a predetermined maximum angle. | 7 |
INTRODUCTION
The present invention relates generally to the application of programmed computer systems and more particularly to a method and apparatus for playing a game, wherein a player accesses, through a common telephone, an interactive audiotex voice communication device enabling the player to send and receive information in a predetermined sequence and under predetermined controls.
DESCRIPTION OF THE PRIOR ART
It is known to access computer-stored data through a telephonic communications network. In one form, information is obtained by employing a common telephone touch pad, creating alpha or alpha-numeric signal sequences which trigger the transmission of a request for information to a remotely located data base, a synthesized voice signal being used to carry the information requested back to the telephone user. The arrangement allowing this activity is often termed an audiotex voice communication device. The present invention utilizes the basic structure of such audiotex voice communication devices, however, in a novel arrangement which allows the caller to play a game.
SUMMARY OF THE INVENTION
This invention contemplates an apparatus and method for playing a game, and in its preferred form a spelling game, wherein a player enters a telephone number, and, if required, credit information, to obtain access to a specifically programmed audiotex interactive voice communication device. The audiotex device enables the user to interact with the device by attempting to spell, under supervision, a sequence of words which are automatically pronounced or defined for the player. In a preferred form, the results are tallied and reported by the audiotex device at the conclusion of the game.
BRIEF DESCRIPTION OF THE DRAWINGS
While the invention is particularly pointed out and distinctly claimed in the concluding portions herein, a preferred embodiment is set forth in the following detailed description which may best be understood when read in connection with the accompanying drawings in which:
FIG. 1 is a partial block diagram schematically showing a relationship between a common telephone interfaced with an interactive audiotex voice communication device arranged for enabling the user to play a spelling game.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to FIG. 1, the reference numeral 1 designates multiple signal input means in the form of a conventional key pad 1 of a schematically illustrated, common telephone 2. The telephone 2 includes a sound signal transmitter 3 associated with a microphone or mouthpiece 4 and an earpiece or receiver 5 which converts controlled electronic signals to voice language sound for reception by the user.
An appropriate communication facility interface 6, for example, a PBX (private branch exchange) or an ACD (automatic call distributor) or other type of commonly used switching unit, is functionally positioned in the usual manner to relay signals to and from the telephone 2.
The interface 6 is, in turn, functionally connected to a schematically illustrated, normally remote, audiotex device 7. The audiotex device 7 is preferably of the type known as a "large-line, interactive system", designed to support a plurality of simultaneous functions, including answering multiple incoming telephone calls and multiple caller prompting. The prompting function invites caller interaction with predetermined and recorded data by urging the caller to press signal producing keys, forming the active portion of the telephone key pad 1.
More particularly, the audiotex device 7 is adapted to respond to appropriate key produced signals by issuing digitized information which is transformed into audio message signals through a data base computer 8 cooperating with a voice synthesizer 9. Control of the audiotex device 7 is maintained through a processor 10 which communicates with a response storage unit 11. The unit 11 stores signals constituting the responses of the caller to the prompting. The voice synthesizer 9 converts data base stored signals to signals which, at the receiver 5, become easily recognizable audio words to the caller.
The telephone 2, in order to best communicate and function in association with currently available audiotex units, is preferably of the well known dual tone, multifrequency type having twelve keys 12, eight of which are respectively associated with a single number digit 13 and three alphabet letters 14. The remaining keys are sometimes referred to as "special function" keys, but are capable of producing similar signals, although at different, dedicated frequencies.
In practicing the invention, a caller enters a telephone number in the usual manner by sequentially pressing selected keys 12, thereby accessing and triggering the audiotex device 7 to deliver a first predetermined synthesized voice message to the caller. Typically, the first voice message includes an offer to initiate a spelling game with instructions for the player to indicate, by pressing a designated key, a desire to play and receive gaming data, in this example, in the form of the first word of a sequence of words to spell.
If the caller (player) elects to enter the signal in accordance with the instructions, the audiotex device 7 responds by selecting the first word (randomly or in a predetermined order) from a recorded bank of words, and transmit same by synthesized voice to the receiver 5, where it becomes intelligible sound to the player.
Within a measured time limit, the player attempts to spell the word by entering a sequence of dial pad key signals through pressing selected keys of the multiple key pad 1. As noted above, specific dial pad keys are associated with particular letters of the alphabet and the player presses the keys corresponding to what the player believes to be the letters and sequence thereof needed to correctly spell the first word. For example, assuming that the first word is "cat", the player presses the key associated with "c", then presses the same key again, since that key is also associated with the letter "a", and subsequently presses the key associated with the letter "t". The data base computer 8, in this case receiving tone signals generated by the keys numbered 2 and 8, will recognize the sequence of signals 2-2-8 as correctly spelling "cat".
If the spelling sequence is correctly completed within the limited time period, the audiotex unit 7 is triggered to initiate a sequence of events which includes (1) informing the player that the word has been spelled correctly and (2) instructing the player to indicate, by a particular key pad signal, a desire to receive the second voice word. If the player so indicates, the audiotex device then proceeds to select and deliver the second voice word to the player through the telephone receiver 5. The foregoing exchange between the audiotex device 7 and the player is repeated for a predetermined plurality of words, after which the audiotex device informs the player, through words produced by input to the voice synthesizer, of the number of words correctly spelled in the total of words supplied.
Several variations of the game are possible; for example, the player may be informed that a prize has been won for making a predetermined "score"; the words to be spelled, provided by the audiotex device, may be generated in a particular sequence or randomly selected under predetermined criteria from the data base within the data base computer; the audiotex unit may be programmed to limit the number of times or games in which each player may participate during a particular time period to prevent abuse; prizes of various values may be announced for achieving scores, using more or less difficult words and/or the arrangement may be particularly adapted for teaching purposes, rather than utilizing a contest format.
Other variations available include a request by the audiotex device that the player spell a synonym for the word presented, rather than pronouncing the word, or spell a word which constitutes the answer to a verbalized question or description.
Note that for words containing the letter "q" or "z", which are sometimes not found on standard telephone key pads, the signal created by the key identified with the numeral "0" or "1" may conveniently constitute the "Q" and/or "Z" signal recognizable by the audiotex unit.
The game may be played on a rotary dial telephone (not shown) by the player using voice signal to clearly pronounce the numbers of the keys which would otherwise be pressed to identify the respective alphabet letters. Such capability, however, contemplates the use of a voice number recognition unit as part of the processor 10 in the audiotex device 7. In a more sophisticated version, where the audiotex device is programmed to recognize voice signals of letters directly, the letters may be spoken for playing the game. In this version, it may be more convenient to use the voice signals for input to the audiotex device regardless of the type (touch tone pad or rotary pulse) telephone.
The "*", "0" "1" or "#" keys on standard key pads may be used to provide other features, such as a request for the audiotex unit to repeat the pronunciation of a word, adjust volume, request a "live" operator, etc.
It may be desirable that the audiotex unit be programmed to keep track of various individual players by requesting a telephone number, social security number or preassigned number of the player. In the alternative, such identifying number may be requested when identification is necessary because a prize has been won. In any case, the identifying number may be entered in the same manner as entering a usual telephone number, that is, by pressing keys in sequence.
Other variations of the game may be practiced utilizing the basic system described, such as a scrambled letter game, where a group of letters in improper sequence is given to the player, who must put them in the correct sequence, or a word game whereby a word is given to the player who notes the group of letters making up the word and recombines them to produce as many words as possible or vocabulary may be tested by giving the player the definition for a word and the player must identify and spell the word.
In a still further modification, the word to be spelled, or other presentation, is not supplied by the audiotex unit, but by other means, such as newspaper, radio or television. The player, in such cases, accesses the audiotex unit by telephone in the usual manner, receives instructions and provides, by key pad signal, the answer for whatever question is involved.
While particular embodiments of this invention have been shown and/or described, it will be apparent that many changes may be made in the form, arrangement, positioning and use of the various elements. In consideration thereof, it should be understood that preferred embodiments of this invention are intended to be illustrative only and not intended to limit the scope of the invention. | Apparatus and method for playing a spelling game, wherein a player enters a telephone number to obtain access to a specially programmed audiotex voice communication device which enables the user to interact with the device by attempting to spell, under supervision, a sequence of words which are automatically pronounced or defined for the player. Spelling is accomplished, in one form, by sequentially pressing common telephone pad keys, the keys being selected by the alphabetic letter associated therewith. | 0 |
[0001] This is a continuation of application Ser. No. 11/816,090 filed Aug. 15, 2008, incorporated by reference herein,
FIELD OF ME INVENTION
[0002] The present inventions relate to apparatuses for enabling users to create transcriptions, closed captions, and/or logs of digitized recordings, for presenting to users the transcripts, closed captions, logs, and digitized recordings in a correlated manner, for enabling users to compose one or more scenes of a production, and for enabling users to compose storyboards for a production.
BACKGROUND OF THE INVENTION
[0003] The entertainment industry has developed a new genre of movie/television entertainment called “Reality TV,” or “unscripted programming.” In this genre, untrained actors are placed in various settings with general direction and rules to guide their interactions, but without a specific script for actions or dialog. Beforehand, the production staff has a general idea of the storyline for the production, but the final storyline will depend upon the interactions that take place. Several video cameras are located within the settings and record the interactions among the actors for long periods of time. Various stimuli may be introduced into the settings by the production staff to provoke unpredictable interactions among the actors. After several settings have been videotaped for several hours over several days by several cameras, the production staff reviews hundreds to thousands of hours of videotape and constructs a final storyline for the TV production (i.e., media work).
[0004] In a typical production, the raw video material is reviewed by several people, typically in the range of 10 to 50, each doing a specific task, such as logging, transcribing, scanning for story points, story writing, and setting creative directions. To review raw video material, each of the hundreds of videotapes is duplicated several times, and the duplicates are distributed among the production staff. Transcribers then create transcripts of the tapes, and loggers create files that describe the actors and actions present in each tape. The transcripts and logs are then reviewed by storywriters, producers, and directors to identify video tapes to review and to develop storylines for the TV production. The large volume of video material, however, has made it difficult for the production staff to communicate with one another and correctly identify important video scenes. This impedes the creativity and productivity of the producers and the storywriters. In addition, the task of navigating between the transcripts, logs, and video tapes for a user is difficult and time-consuming. Because of this difficulty, and because of the need to have physical access to the duplicate tapes, the production staff is essentially forced to work out of a central facility.
[0005] The above problems have hindered the production and development of unscripted programming. A solution to these problems is needed to ease the production of unscripted programming and to enable the genre to expand in new creative directions.
SUMMARY OF THE INVENTION
[0006] The present inventions provide methods and apparatuses that address these problems.
[0007] The present inventions encompass a first exemplary multipurpose media player for playing a digital medium to a user, wherein the digital medium comprises at least an audio stream, video stream, or both, and for enabling the user to interact with a data file corresponding to the digital medium. The first exemplary multipurpose media player comprises a data processor, a display coupled to the data processor, an audio output device coupled to the data processor, and a user interface to receive input text and commands from the user. The user interface has at least a keyboard coupled to the data processor. The first exemplary multipurpose media player further comprises a first set of instructions that directs the data processor to present the digital medium to the user, and a second set of instructions that directs the data processor to receive keystrokes from the keyboard, to store representations of the keystrokes in a data file. The first exemplary multipurpose media player further comprises a third set of instructions that directs the data processor to detect a first preselected input command from the user interface and to insert a time-code indication into the data file upon detection of the first preselected input command, the inserted time-code indication being representative of the playing time of the digital medium at which the first preselected input command was detected. The first exemplary multipurpose media player further comprises a fourth set of instructions that directs the data processor to display representations of the keystrokes and the inserted time-code indications on the display.
[0008] The first exemplary multipurpose media player enables a user to view a digital medium and prepare a data file describing the actions and content of the medium at specific playing times of the medium, with those playing times being delimited by time-code indications. In preferred embodiments of the first exemplary multipurpose media player, each time-code indication comprises a hyperlink to the medium which causes the media player to position the playing time of the medium to the time specified by the time-code when the hyperlink is activated by the user.
[0009] The present inventions also encompass a second exemplary multipurpose media player for playing a digital medium to a user, wherein the digital medium comprises at least an audio stream, video stream, or both, and for enabling the user to interact with a data file corresponding to the digital medium. All or part of the second exemplary multipurpose media player may be incorporated with the first exemplary multipurpose media player, including the preferred embodiments thereof. The second exemplary multipurpose media player comprises a data processor, a display coupled to the data processor, an audio output device coupled to the data processor, and a user interface to receive input text and commands from the user. The user interface has at least a keyboard coupled to the data processor. The second exemplary multipurpose media player further comprises a first set of instructions that directs the data processor to present the digital medium to the user, and a second set of instructions that directs the data processor to receive keystrokes from the keyboard, and to store representations of the keystrokes in a data file. The second exemplary multipurpose media player further comprises a third set of instructions that directs the data processor to present to the user two or more classes of information, each class capable of having a plurality of members, and a fourth set of instructions that directs the data processor to detect a preselected user input command for each member and to insert a text representation of a member in the data file upon detection of the preselected user input command for the member. The second exemplary multipurpose media player further comprises a fifth set of instructions that directs the data processor to display representations of the keystrokes and inserted representations of members on the display.
[0010] The second exemplary multipurpose media player enables a user to view a digital medium and prepare a data file describing the content and activities of the medium, with the ability to insert common text descriptors, such as actor names, scene locations, activities, etc., with preselected user input commands that are easier and quicker to provide than the full keystroke of the text descriptors. Preferred embodiments of the second exemplary multipurpose media player further comprise an instruction set that directs the data processor to receive a preselected user input command to add a new member to a class; an instruction set that directs the data processor to receive a preselected user input command to delete a member from a class; an instruction set that directs the data processor to receive a preselected user input command to add a class; an instruction set that directs the data processor to receive a preselected user input command to delete a class; an instruction set that directs the data processor to obtain a group of classes and the members of the classes from a configuration file; and an instruction set that directs the data processor to save an active group of classes and the members of the classes to a configuration file.
[0011] The present inventions also encompass a third exemplary multipurpose media player for playing a digital medium to a user, wherein the digital media comprising at least an audio stream, video stream, or both, and for enabling the user to interact with a data file corresponding to the digital medium. All or part of the third exemplary multipurpose media player may be incorporated with the first and second exemplary multipurpose media players, including combinations and the preferred embodiments thereof. The third exemplary multipurpose media player comprises a data processor, a display coupled to the data processor, an audio output device coupled to the data processor, and a user interface to receive input text and commands from the user. The third exemplary multipurpose media player further comprises a first set of instructions that directs the data processor to present the digital medium to the user, and a second set of instructions that direct the data processor to display a data file to the user, the data file having at least one time stamp representative of a playing time of the digital medium. The second set of instructions further directs the data processor to display a hyperlink of the at least one time stamp. A third set of instructions directs the data processor to recognize an activation of the hyperlink of the at least one time stamp, and to set the current playing time of the digital medium to the time code indicated by the at least one time stamp.
[0012] The present inventions also encompass scene editors that enable users to compose scenes from media clips, and storybook editors that enable users to compose episodes and acts of one or more storyboards from the scenes that the create. In preferred embodiments of the scene editors of the present application, clips may be imported from text data files created by exemplary multipurpose media players according to the present application, and embodiments of storyboard editors according to the present application may call up instances of the scene editors of the present application to edit scenes of a storyboard.
[0013] The structures of the present inventions enable the multipurpose media players to be embodied within Internet browser environments, thereby providing high availability of the multipurpose players across software platforms, networks, and physical locations.
[0014] Methods according to the present invention encompass the tasks underlying the above apparatus embodiments, as well as other embodiments described below.
[0015] The present invention also encompasses an exemplary method of enabling a user to generate a description of a digital medium, the digital medium having at least an audio stream, video stream, or both. The method comprises receiving a digital medium from a server over a network connection, playing the digital medium to the user, receiving keystrokes from a keyboard, storing representations of the received keystrokes in a data file, displaying the representations of the received keystrokes on a display, and sending the data file to the server over a network connection. While the scene editors and storybook editors may be used separate from the multipurpose editors by a user, the combination of all of these provides the user with great power, flexibility, and efficiency in making media productions.
[0016] Accordingly, it is an object of the present invention to enable the facilitation of the production of media works and the like.
[0017] It is another object of the present invention to provide production staff with more organized access to recordings and other content assets used to construct media works.
[0018] It is another object of the present invention to enable production staff to decrease the amount of time needed to create a media work from recordings and other content assets.
[0019] It is yet another object of the present invention to provide production staff with the ability to explore a greater range of creativity in their media works.
[0020] These objects and others will become apparent to one of ordinary skill in the art from the present specification, claims, and attached drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0021] FIG. 1 illustrates a first exemplary multipurpose media player according to an invention of the present application.
[0022] FIG. 2 shows an exemplary set of display screens according to an invention of the present application.
[0023] FIG. 3 illustrates an exemplary text data file according to an invention of the present application.
[0024] FIGS. 4A-4D illustrate various user-input commands according to an invention of the present application.
[0025] FIG. 5 illustrates exemplary instruction sets embodied on a computer readable memory as a computer program product according to an invention of the present application.
[0026] FIG. 6 is an exemplary main page of a scene editor according to an invention of the present application.
[0027] FIG. 7 is an exemplary view screen of a scene editor according to an invention of trio present application.
[0028] FIG. 8 is an exemplary Edit Decision List generated by a scene editor according to an invention of the present application.
[0029] FIG. 9 is an exemplary edit screen of a scene editor according to an invention of the present application.
[0030] FIG. 10 shows an exemplary text data file from which scene clips are being imported from by a scene editor according to an invention of the present application.
[0031] FIG. 11 shows the exemplary text data file of FIG. 10 with a secondary dialog box displayed thereon as generated by a scene editor according to an invention of the present application.
[0032] FIG. 12 illustrates exemplary instruction sets embodied on a computer readable memory as a computer program product for an exemplary scene editor according to an invention of the present application.
[0033] FIG. 13 is a page of a storybook editor according to an invention of the present application.
[0034] FIG. 14 is an exemplary view screen of a storybook editor according to an invention of the present application.
[0035] FIG. 15 is an exemplary edit screen of a storybook editor according to an invention of the present application.
[0036] FIG. 16 is an exemplary scene selection dialog box of a storybook editor according to an invention of the present application.
[0037] FIG. 17 illustrates exemplary instruction sets embodied on a computer readable memory as a computer program product for an exemplary storybook editor according to an invention of the present application.
DETAILED DESCRIPTION OF THE INVENTION
[0038] An exemplary multipurpose media player 100 according to the present inventions is shown in FIG. 1 and comprises a data processor 110 , a display 120 coupled to data processor 110 to provide visual output to the system user, an audio output device 125 coupled to the data processor, a user interface 130 to receive input text and commands from a human user, and a plurality of instruction sets embodied on a computer-readable medium 140 (e.g., memory, disc storage, etc.) that direct the processor to conduct various operations, as described below in greater detail. User interface 130 includes a keyboard 132 , and preferably a pointer-control device 134 , such as a mouse. The pointer-control device sends signals to data processor 110 to control the motion of a pointer on display 120 . In addition, the user interface may include a foot-pedal control device 136 having two or three pedals for controlling the play direction of the media (e.g., rewind, play, pause, and fast-forward).
[0039] Multipurpose media player 100 enables a human user to play a media stream in a first display area 210 of a computer screen, and to compose text notes in a data file that is displayed in a second display area 220 of the computer screen. FIG. 2 shows exemplary instances of these display areas, with the first display area 210 disposed directly over the second display area 220 . It may be appreciated that the screens can be placed in other orientations with respect to one another, such as side-by-side. The media stream may comprise an audio stream, a video stream, or a combination of audio and video streams (preferably synchronized in time). The latter is shown in FIG. 2 .
[0040] In display area 210 , a media player is provided that enables a user to play, pause, rewind, and fast-forward through a media file with conventional play/pause, rewind, and fast-forward buttons arranged along the bottom of area 210 (the play and pause functions are provided as a toggle on one button). These buttons correspond in function to the rewind, play/pause, and fast-forward pedals on foot-pedal control device 136 . The media player also preferably provides a search button at the bottom of area 210 (the button with the binoculars) to set the media player to a selected time point, as specified by hours in the adjacent “HH:” box, minutes in the “MM:” box, seconds in the “SS:” box, and frames in the “FF:” box. These boxes are normally updated with values that indicate the time code of the frame currently being played. When the search button is clicked, playing is paused, and the user is allowed to enter a time code in the boxes. The button may be configured such that a second click then causes the media player to go to the video frame corresponding to the entered time code. In addition, the player provides audio mute and volume controls. Finally, a file open button to open a desired media file is provided in area 230 . The media player may be provided by a group of instruction sets disposed on computer-readable medium 140 .
[0041] In display area 220 , a text editor is provided to enable the user of multipurpose media player 100 to compose text notes in a data file. Standard file handling buttons (open, save) and formatting buttons are provided along the top of area 220 . As discussed in greater detail below with reference to exemplary embodiments, the opening and closing of media files and text data files may be coordinated so that the text data file being edited correlates to the media file being played. In such cases, the file handling buttons in areas 220 and 230 may be coordinated by the same set of instructions.
[0042] The text notes entered by the user may comprise one or more of the following items: transcribed dialog; a logging of activities, locations and characteristics of one or more scenes in the audio/video stream(s); production notes; storyline notes; other information. Selected character patterns may be used to distinguish one or more of these classes of items. FIG. 3 shows a portion of an exemplary text data file with text notes. As an example, and as illustrated in FIG. 3 , transcribed dialog may appear as normal text, the name of the actor speaking the transcribed dialog may appear in uppercase letters preceding the transcribed dialog, logging information (such as actions and weather conditions) may appear between round brackets “(” and “)”, production notes may appear between square brackets “[” and “]” or in all capital letters, and storyline notes may appear between braces “{” and “}”. In addition, different colors and fonts may be used. The data file may comprise the rich text format, or a variant thereof.
[0043] Multipurpose media player 100 further enables a user to insert time stamps into the text data file, with the time stamps having hyperlinks to the media stream. Upon clicking on a time-stamp hyperlink, the processor repositions the playing of the media stream to play starting from the time point indicated by the hyperlink. The user is able to insert time stamps into the text data file at will. For example, the user may insert a time stamp and a corresponding hyperlink at: (1) the beginning of a scene, (2) a change of a condition in a scene (location, lighting, weather, etc.), (3) the start of each transcribed sentence of dialog, (4) the end of each transcribed sentence of dialog, (5) various points in a storyline, etc. Each time stamp and hyperlink preferably comprises a format based on the SMPTE time code format. The SMPTE time code typically has the following formats: HH:MM:SS.FF or HH:MM:SS:FF, where HH is the hour of the playing time, MM is the minute of hour HH, SS is the second of minute MM, and FF is the frame number of second SS. A time-stamp appearing in a text data file preferably has one of these two forms, and a hyperlink preferably includes the four data fields of the time code (HH, MM, SS, and FF).
[0044] Each time stamp and corresponding hyperlink inserted into the text data file is to be referenced to the particular medium that is being played. To establish this reference, a media identifier may be included in the data file as human readable text at a specific location, or delimited by special characters or formatting, or may be included in machine readable form embedded in the data file as metadata. Both are shown in combined form in the example of FIG. 3 . When a user clicks on a time-stamp hyperlink, the processor can use the media identifier to load the media into the playing window, if it is not already loaded there. This type of referencing is called “relative referencing” because the time-stamp hyperlink does not specifically identify the media to which it refers, and is interpreted with reference to the media identifier stored in the data file. As another approach, the reference may also be established by embedding the media identifier into each time-stamp hyperlink. For example, the hyperlink may comprise the network address of the media to which it refers and the SMPTE time code. (The network addressing system also includes files stored on the local file system.) This enables a single file to contain references to the SMPTE time codes of two or more separate digital media files. This feature is useful to storywriters, editors, and producers in that it enables each to construct a storyboard for a work in a single file that can reference and play scenes from several different sources. The type of referencing is called “absolute referencing” because the time-stamp hyperlink contains the identity of the media to which it refers. Both relative and absolute referencing may be used in a data file. For example, each time-stamp hyperlink that does not contain a media identifier may be interpreted by the data processor as being referenced to a common media identifier stored elsewhere in the data file.
[0045] As yet another approach, which may be referred to as implicit relative hyperlinking, the filenames of the media file and text data file are coordinated such that each has the same base name but different file extensions (i.e., different file types), and such that each is placed in the same directory, or separate but a priori known directories. For example, the text data file may be named “BaseName.rtf” and the media file may be named “BaseName.mpg”. A click on a time-stamp hyperlink in a text data file would then be interpreted as a request to play from the media file with the same base name as the text data file at the time code provided by the time-stamp hyperlink. The approach enables the two files to be easily moved to different instances of multipurpose media player 100 (e.g., moved to different computer systems), but it can limit the user to having only one text data file per media file. However, this limitation can be addressed by expanding the filename of the text data file to include additional identifying characters separated by a special character, such as “_”. An example of this would be: “BaseName_IdentifyingCharacters.rtf” for the text data file, which would be correlated with the media file “BaseName.mpg”, but where the field “Identifying Characters” could be different for several different text data files that had logging/transcription information on the media file “BaseName.mpg”.
[0046] To facilitate the logging of activities, locations, characteristics, etc. of scenes, preferred embodiments of the present invention provide the user with the ability to create one or more logging classes, and the ability to add members to each logging class. For example, one logging class may contain the names of the actors, with each actor being a member; and another class may contain various location identifiers (e.g., kitchen, living room, hallway, outside, etc.). In addition, these preferred embodiments of the present invention provide the user with the ability to assign a keyboard shortcut to each member so that the member can be entered into the data file with just the entry of the corresponding keystroke or combination of keystrokes. A keyboard shortcut may comprise a function key on a standard computer keyboard (e.g., keys F1 through F12) or may comprise a keystroke combination of two keys, with one of the two keys being the “Ctrl” key or the “Alt” key. As another approach, which may be used in combination with the above, an on-screen menu may be presented for each class, and the user may select a member of a class from a menu using pointer-control device 134 (e.g., a mouse). As yet another approach, a function key may be used to temporarily display a menu of the class members on the screen, and a member may be selected by scrolling to it with the keyboard's up/down keys and then pressing the enter key. These approaches are examples of preselected user input commands. A set of classes, each with their members, may be pre-generated and stored for long-term use. Also, several such sets of classes may be pre-generated and stored. When a media stream is to be transcribed and/or logged, the user can select a desired set of classes to use (e.g., access) by a menu command. In addition, preferred embodiments of the present invention enable the user to define new classes, to add new class members to new and existing classes during the transcription/logging process, and to save the new class sets and modified class sets for reuse.
[0047] FIG. 4A shows an area 240 having a plurality of menu interfaces for selecting members from the various logging classes, and causing the names of the members to be inserted into the text data file, which is shown in the window in area 220 . Area 240 may be brought to the display area by the user typing a preselected hot-key, or by clicking on a submenu under the “View” menu tab in area 230 . Seven exemplary classes of logging information are provided: subject (i.e., the actor or person whose dialog is being transcribed), scene location, scene activity, scene weather, shot type, tradeouts, and other (to handle miscellaneous items). Provided for each class are: a drop-down menu (blank text box with down-arrow button), an add button (square button labeled “A”), and a delete button (square button labeled “D”). When the user positions the display pointer over the down-arrow button of a drop-down menu and executes a mouse click, a listing of members appears in a dialog box below the menu, as shown in FIG. 4B . The user may then move the display pointer to a desired member of the class, which causes the member to be highlighted on the screen, and then execute another mouse click to select the member. This causes a text representation of the selected member to be entered in the text data file (shown in area 220 ) at the cursor location of the editor (the place where new text is being entered into the file). When the user clicks on an add button, another dialog box is brought up, as shown in FIG. 4C . The dialog box provides an empty field for the user to enter the text description of the new member for the class, an “Add” button for the user to click to add a new member using the provided text, and a “Cancel” button for the user to escape out of the addition process. As an option, and as shown in FIG. 4C , the existing members of the class maybe listed to provide confirmation to the user that the appropriate class has been selected, and that the newly-added member is not a duplicate. When the user clicks on a delete button, another dialog box is brought up, as shown in FIG. 4D , which provides a listing of the class members from which to select, a “Delete” button for the user to click to delete a selected member, and a “Cancel” button for the user to escape out of the deletion process. To delete a class member, the user positions the display pointer over the member to be deleted and executes a mouse click to highlight the member, and then clicks on the “Delete” button.
[0048] In addition to using the multipurpose media player to create a log and transcription of a medium, a user can use the multipurpose media player according to the present invention to create edit decision lists (EDL files), Avid Log Exchange lists (ALE files), and similar files. Each of these lists is a record of all locations (by time code) of a media file at which selections or other edits are to be produced. The absolute referencing feature enables one to create an EDL or ALE file that refers to several media files.
[0049] In order to facilitate the integration of the multipurpose media player with other processes in the production environment, preferred embodiments of the present invention include menu-driven routing and accessing of text data files. As one routing feature, a data file that has been created by a user may be e-mailed to another person by clicking a link in a drop-down menu. The e-mail menu may list specific individuals by e-mail address or name identifier on tabs of the menu, and/or may have a menu tab that opens up a dialog box to select a person in a contact file or receive a typed-in e-mail address. As another routing feature, a data file that has been created by a user may be sent to a network server, storage device, or other network resource by FTP (file transfer protocol). To do this, the user may click on the “File” menu tab in area 230 to select a submenu, which we call the file transfer submenu. This submenu may list specific network servers or addresses on individual tabs of the menu, and/or may have a tab that opens up a dialog box to select a network server or resource. As an accessing feature, the multipurpose media player can communicate directly with one or more database filer servers to read and write thereto various data files, such as media files, log files, transcript files, note files, storyline files, etc. This feature is most readily presented to the user by way of an open file dialog box.
[0050] The above features may be implemented by various instruction sets that direct the data processor 110 ( FIG. 1 ) to undertake specific tasks. One general approach of implementing the instruction sets is to divide the instruction sets into two groups. The first group directs data processor 110 in the task of playing the media file in the first display window ( FIG. 2 ) in response to commands from user interface 130 , and in the task of responding to requests generated by the second group of instruction sets. The second group of instruction sets direct data processor 110 in the task of displaying the text data file in the second display window ( FIG. 2 ) and modifying the text data file in response to commands from the user interface 130 (thereby enabling the user to edit the file). The second group of instruction sets sends specific requests to the first group of instruction sets, with the latter group providing responses. Such requests may include a request for the filename of the medium currently being played by the first group of instructions, a request for the time code of the current video frame being played, a request for the first group of instructions to set the play time to a specific time-code value, as well as to pause, play, and rewind the playing of the medium, and a request for the first set of instructions to open a specified digital media file for playing. In some embodiments, and as described below in greater detail, part of the second group of instruction sets may be divided out as a third group of instruction sets, with the third group directing the data processor to handle the requests and communications between the tasks directed by the first and second groups of instruction sets.
[0051] In conventional operating systems such as Microsoft Windows and Apple's Mac OS, several instruction-set groups may be run by separate parallel processes on data processor 110 , with the operating system allocating recurring slices of processing time to each of the processes in a multiplexed manner, and providing communication facilities for the processes to communicate with one another. As such, the tasks performed by each instruction-set group may be performed substantially in parallel with the tasks performed by the other instruction-set groups. In this case, the first, second, and optional third groups of instruction sets may be run by respective parallel processes, with communications between the tasks of these groups being routed through the inter-process communication facilities of the operating system. Conventional operating systems also enable programmers to run several instruction-set groups under one process, but with each instruction-set group being handled by a respective thread of process execution. This enables the programmer to handle the communications between the instruction-set groups within the program's own environment, without relying upon the inter-process communication facilities of the operating system. In this case, the first, second, and optional third groups of instruction sets may be run by respective parallel threads of execution within a single process, with communications between the tasks of these groups being managed by data objects and methods that are global to all of the threads.
[0052] The division of the instruction sets into these two or three groups enables one to implement the first instruction-set group with one of several commercially available media players that run on personal computers, such as Microsoft Windows Media Player 10, with the media player being configured by the second or third instruction-set groups for the tasks needed for the embodiments of the present invention. Many commercially available media players, such as Microsoft Windows Media Player, can operate as standalone processes on a personal computer, interfacing with the operating system to receive mouse commands and keystrokes from the keyboard when the media player is selected as the active window. In addition, these media players, including Microsoft Media Player, also include application program interfaces (APIs) that enable a programmer to write a program that starts an instance of the media player running on a respective process or thread, and thereafter controls the operation of the media player by providing commands and inputs to it through the API. In both cases, the media player comprises instructions that direct data processor 110 to present the digital medium to the user via display 120 and audio output device 126 . The APIs of the media player provide several command instructions that a programmer can invoke from a number of programming languages (e.g., C++, Java, Visual Basic, etc.). Some of these command instructions enable a programmer to obtain information about the medium that is being played and how it is being played; others enable a programmer to set the parameters and playing state of the player; and still others enable a programmer to configure the appearance of the player, such as rearranging the input buttons and including additional buttons and input fields. To use the media player in this dependent manner, the manufacturer typically provides a dynamic-link library (DLL) which comprises the instruction sets for directing the data processor to implement the media player and the APIs. The programmer creates an instruction-set group having API command instructions (such as through an editing and compilation process), and then assembles the instruction-set group with the DLL of the media player to create a complete application program.
[0053] The second group of instruction sets may be implemented as newly-written instructions that implement a conventional text editor plus special-purpose instruction sets that communicate with the media player and control it, and that direct the processor to perform tasks that implement features of the present invention. The computer source codes (i.e., instruction sets) of several public-domain text editors are available for purchase or downloading over the Internet, and can be augmented to incorporate the special-purpose instruction sets of the present invention. The text editor preferably includes instructions that direct data processor 110 to receive keystrokes from the keyboard and store representations of the keystrokes in a text data file, to enter hyperlinks (e.g., file links, html links and variants thereof) into the text data file, to interpret (e.g., handle) hyperlinks in the text data file, and preferably to create and/or save the text data file in rich-text format (RTF), a convention established by Microsoft. As another approach, many commercially-available text editors, such as Microsoft Word, Chado SpellEditor, and Tx Text Control, have DLLs and APIs that enable a programmer to start a dependent instance of the text editor running on a respective process or thread, and thereafter control the operation of the dependent instance of the text editor by providing commands and inputs to it through its API. The API typically enables a programmer to add dialog boxes to the text editor, modify and insert text, add special text and event handling instructions to the editor, and control many aspects of the operation of the text editor by invoking command instructions from one of a number of programming languages (e.g., C++, Visual Basic, etc.). In this approach, the instruction sets of the editor are not changed, but rather a program of special-purpose instruction sets (such as the above-described third group of instruction sets) is created. This program comprises an instruction set that directs data processor 110 to start a dependent instance of the text editor running on a respective process or thread, and to thereafter configure and control it to perform tasks of the present invention using command instructions to the API of the text editor. In this case, a DLL for the text editor is provided by the manufacturer, and this DLL is assembled with the program to create a complete application program.
[0054] The special-purpose instruction sets according to the present invention include:
1. An instruction set that directs data processor 110 to coordinate the first and second groups of instruction sets (e.g., media player and text editor) so that the data file currently being edited by tasks directed by the first group of instructions corresponds with the medium being played by tasks directed by the second group of instructions. 2. An instruction set that directs data processor 110 to set up classes (e.g., “Subject,” “Location,” etc.), and enables a user to edit membership. 3. An instruction set that directs data processor 110 to enable a user to select a member of a class and to insert a text representation of the member in the text data file with one or more keystrokes and/or mouse clicks. 4. An instruction set that directs processor 110 in the following tasks: to detect an input request by a user to insert a time-stamp hyperlink into the text data file; to obtain the time code of a currently-played frame from the media player; and to insert a time-stamp hyperlink in the text data file that bears the received time code and that is located at the cursor position in the text data file. These instructions enable a user to insert a time-stamp hyperlink into the text data file that corresponds to the current playing time of the medium being played. 5. An instruction set that directs processor 110 to recognize the user's activation of a time-stamp hyperlink in the text data file, and to send a command to the media player to cause the media player to set its current playing position to the time code indicated by the activated time-stamp hyperlink. This instruction set enables the user to click on hyperlinks in the text data file to cause the media player to go to specific time points in the medium being played. 6. An instruction set that directs data processor 110 to enable a user to send the text data file to a designated party via e-mail or to upload the data file to an FTP server on a directory.
Given the above description of the present invention and the above special-purpose instruction sets, it is within the ordinary skill of a person versed in the software art to construct these instruction sets and to integrate them with media players such as Microsoft's Windows Media Player and Apple's Quicklime, and with text editors such as Chado's SpellEditor, TX Text Control Editor, and Microsoft's Word. The manufacturers of each of the media players and text editors provide software development kits (SDKs) for these components that document the APIs, many of which are readily accessible over the Internet.
[0061] As indicated above, a portion of the second instruction-set group can be divided out as a separate third instruction-set group. In this approach, the first instruction-set group provides an instance of a dependent media player (the first instruction-set group may be provided as a DLL, with APIs, of a commercially available media player), and the second instruction-set group provides an instance of a text editor (the second instruction-set group may be provided as a DLL, with APIs, of a commercially available text editor). The third instruction-set group starts the instances of the media player and text editor, coordinates and controls the communications between the user and these instances, handles the communications between the instances, and implements the above-enumerated special-purpose instruction sets. In this approach, the third group of instructions comprises a “wrapper” program composed in Microsoft's Visual Basic or Visual Basic.NET, or as an application program implemented in C++ or C#, or further yet as a script program that is downloaded into a web browser. The latter approach enables the multipurpose media player to be web-browser-based whereby the user need only have a web browser and a media player pre-installed on the user's computer, and where the wrapper and the text editor (such as in the case where TX Text Control is used) are downloaded over the Internet at the time of use by the user, and where the wrapper takes control of the browser window upon being downloaded.
[0062] We describe in detail one embodiment where the third group of instructions comprises a wrapper program as its framework. The wrapper comprises several sets of instructions, and may be constructed by a visual basic editor (where the instruction sets are displayed to the programmer at a high level), or a script editor (in the case where the wrapper is constructed to be downloaded into a web browser). The important instruction sets of the wrapper, text editor, and media player are illustrated in FIG. 5 , and described in greater detail below. The instruction sets shown in FIG. 5 may be embodied, in all or in part, on a computer readable medium and a computer program product. Referring to FIG. 4A , a first set of instructions sets up a graphical-user-interface (GUI) container 200 that defines a first area 210 in the container where the graphical-user-interface of the media player is placed, a second area 220 in the container where the graphical-user-interface of the text editor is placed, and third and fourth areas 230 and 240 wherein graphical-user-interfaces for the wrapper itself are placed. For web-browser implementations, the container can be set up within a browser window. User inputs provided to the container are routed through the wrapper so that it can detect selected hot-key commands and/or mouse commands (e.g., event detection), and can route each user input to the appropriate component (wrapper, player, or text editor) depending upon which area of the container the user is clicking on or entering text at. For this, the wrapper program comprises an instruction set that directs data processor 110 to define container 200 , to start instances of the text editor and media player (typically on separate execution threads), and to configure communication protocols between the wrapper and these instances, including routing of user input and event handling.
[0063] The wrapper further comprises an instruction set to direct data processor 110 to receive input from the user as to which text data file or media file to open, and to coordinate the opening of the text data file by the text editor and the corresponding media file by the media player. The latter input can be provided under a menu selection “Open” under the “File” tab in area 230 , and can also be provided as a short-cut keystroke (such as “Ctrl-O”). This selection or keystroke brings up a conventional file-system dialog box that lists the files in the current working directory, and allows the user to browse around to other directories and to select another working directory as the current directory. The File System includes files stored on local disk drives attached to the computer running the wrapper, or files stored on file servers accessible by the wrapper over a network or the Internet, or both. The dialog box also permits the user to select a file by highlighting it by mouse click, and then clicking on an “Open” button in the dialog box. Both media files and text data files can be listed in this dialog box, and the user can determine the difference by looking at the file extension or file type indication provided in the dialog box. When the user selects a file to open, the wrapper can use a subset of instructions that direct processor 110 to obtain the file extension or file type of the selected file (by using an API command instruction to the File System), and to determine whether the selected file is a media file or a text data file. If a media file is to be opened, the instruction set directs processor 110 to send a command to the media player to open the requested file. The instruction set also directs processor 110 to locate the corresponding text data file or to create a new text data file if one does not already exist (by using an API command instruction to the File System), and directs the text editor to open the text data file. To coordinate these tasks, both the media file and the corresponding text data file may be kept in the same file directory, and may share the same base filename, but have different file extensions (e.g., “.mpg” for the media file and “.rtf” for the text, data file). When the user selects a text data file to open, the instruction set directs processor 110 to determine the name of the corresponding media file, and to send commands to the text editor and the media player to open the requested files. To determine the filename of the corresponding media file, the instructions can direct the processor to extract the base name of the text data file, and then search the directory for a media file with the extracted base name using API command instructions to the File System. As another approach, the contents of the text data file may be augmented upon initial creation to include the name of the media file (such as in the form of human-readable text and/or hidden metadata), and the instructions may direct processor 110 to read the filename of the media file directly from the text data file by using API commands to the file system to open the text data file and to read the file's characters.
[0064] The above instructions can be structured as a code segment that is activated upon the event of the user clicking on the “Open” menu of the “File” tab in area 230 , and can include API command instructions to the File System (to bring up the open file dialog box, to determine if a corresponding media file or text data file exists in a selected directory, and to create a new text data file when needed), and API commands to the media player and the text editor (to instruct them which files to open). The code segment, as well as any code segment described herein, may be provided in any programming language, including a scripting language. The wrapper preferably also comprises instructions that direct data processor 110 to set up variables (e.g., an object) and to store the filenames of the media file and the text data file in the variables. All of the above instructions can be used to provide the above-enumerated first special-purpose instruction set. It may be appreciated that, in place of the network File System that is made accessible by the operating system, the text data files and the media files can be stored in a database having a set of query and access commands that can be used by the wrapper to access the database in the same way that the wrapper can access the File System.
[0065] To provide the user with the logging classes and members shown in GUI area 240 , the wrapper has the following further instructions. A subset of instructions is executed upon startup of the wrapper and it provides the presentation of the classes in area 240 , along with a drop-down menu for each class, an “add” button (“A”) for each class to add members, and a “delete” button (“D”) for each class to delete members. This subset can comprise generic codes provided by Visual Basic or the script language that are configured to present the specific input fields and buttons (e.g., generic codes that provide window forms). A subset of instructions is also provided to direct data processor 110 upon startup of the wrapper to read a configuration file that contains a listing of the classes and the members of each class, and to populate the drop-down class menus with the corresponding members. A code segment can then be associated with each “add” button and, when the corresponding button is clicked, it directs processor 110 to present a dialog box to the user where the user may enter the name of a new member for the class. The code segment directs processor 110 to take the name and add it to the drop-down menu and the configuration file. Similarly, a code segment is associated with each “delete” button and, when the corresponding button is clicked, it directs processor 110 to present to the user a dialog box listing the members in the class, and to enable the user to highlight a listed member and thereafter remove it from the class by clicking a delete button on the dialog box. In response to this input, the code segment further directs processor 110 to delete the selected member from the drop-down menu and the configuration file. Similar menus and code segments are included to direct data processor 110 to receive user input on adding and deleting classes from the current group of classes in use, and to modify the internal class objects to reflect the additions and deletions requested by the user. The above instructions can be used to provide the above-enumerated second special-purpose instruction set (i.e., the instruction set that directs data processor 110 to set up classes and enables a user to edit class membership). The instructions can use API command instructions to the File System to open, read, modify, and close the configuration files as needed. Typically, the classes are stored as data objects of the wrapper (which are forms of variables), each object containing a listing of the class membership. The objects are initialized with the data from the configuration file upon startup, and are modified by the user's inputs according to activation of the add and delete buttons. Upon exiting the program, the configuration file may be opened and then modified according to the state of the data objects, or rewritten anew according to the state of the data objects. A command to exit the program may be provided by way of a menu selection “Exit” under the “File” tab in area 230 , and by the “x” button at the top right corner of the container. A code segment is associated with each of these inputs, and the code segment may include instructions to update the configuration file with the current state of the class objects.
[0066] In addition, the wrapper may include further instructions to enable the user to select a configuration file to use to populate the classes. A menu selection “Open Class Configuration” may be provided under the “File” tab in area 230 to allow the user to do this. Clicking on this menu selection executes a code segment of instructions that direct processor 110 to do the following tasks; (1) present a file-selection dialog box to the user to select a configuration file, (2) open the selected file and read the contents with API command instructions to the File System, (3) refresh the objects holding the class membership with the data read from the selected configuration file, and (4) close the selected configuration file.
[0067] During the transcription and logging phase, the user is normally typing dialog and other information into the text-editor display in area 220 . The inputs to the wrapper are being routed to the text editor or the media player, depending upon which component (e.g., text editor or media player) was last selected by the user. When the user wishes to insert a member of a class into the text data file, the user may click on a pull-down menu in the wrapper's GUI area 240 (at the down arrow), and then move the display pointer to the member to be selected, as shown in FIG. 4B at 250 . The user executes a second mouse click to make the selection. Upon the selection, the wrapper's instructions direct data processor 110 to generate a text string representative of the selected class member, and executes an API command instruction to the text editor to direct data processor 110 (under the processing thread for the text editor) to insert the contents of the text string at the current location of the text editor's cursor. The text string may include character patterns, such as uppercase letters and the use of brackets and braces as described above, depending upon the class. The selection of a class member may also be made by hot-key. For example, each of the classes can be assigned a function key (such as F1 for Subject, F2 for location, as indicated in FIG. 4B ), and each member in a class may be assigned a letter (such as “A” for Melissa, “B” for Melissa's Mom, etc., as indicated in FIG. B). To insert “MELISSA” as a subject, the user could hit the “F1” key and the “A” key in sequential order. As an aid to the user, and as an option, when a function key is hit, processor 110 can be directed to present a display box or dialog box to the user showing the members of the class corresponding to the function key, with each member presented along with its corresponding letter. To accomplish this, the wrapper can comprise instructions that direct processor 110 to detect the pressing of a function key (event detection), to thereafter display the members of the corresponding class on the screen, to detect the next letter (or the escape key to escape out of the selection), and to correlate the typed letter to the corresponding member. With the selection made, processor 110 may then be directed by the instructions to generate a text string representative of the selected class member along with any corresponding character patterning for the class, and to insert the contents of the text string at the current location of the text editor's cursor, as described above.
[0068] The above instructions can thereby be used to provide the above-enumerated third special-purpose instruction set that directs data processor 110 to enable a user to select a member of a class and to insert a text representation of the member in the data file with one or more keystrokes and/or mouse clicks. Hot-keys, keystroke combinations, selection of menu options and input into dialog boxes are all forms of user input commands.
[0069] During the transcription/logging process, the user can hit a selected hot-key (such as Ctrl-T), or make a mouse click on a specially designated button (“Add Time Stamp” shown in area 240 of FIG. 4A ), to enter a time-stamp hyperlink into the text data file that corresponds to the current playing time of the medium being played. The wrapper may comprise an instruction set that directs data processor 110 to detect the selected hot-key and/or mouse click (such as by event detection), to thereafter obtain the time code of the currently-played frame from the media player (which may be done by an API command instruction to the media player), and to cause the text editor to insert a hyperlink at its current cursor position that has the obtained time code. The last step may comprise the steps of inserting a text string of the time stamp (e.g., “HH:MM:SS:FF”) at the current cursor position by having the wrapper issue an API text-insert command to the text editor, selecting the inserted text by having the wrapper issue an API text select command to the text editor, and converting the selected text to a hyperlink by having the wrapper issue an API link-conversion command to the text editor. The API link-conversion command directs the text editor to convert the selected text into a hyperlink that will generate a link-clicked event in the text editor when the user clicks on the text with the mouse. (The format and handling of the hyperlink is discussed in greater detail below.) Some editors also have API commands that enable hyperlinks to be directly inserted into the file. All of the above-described API commands are typically provided by commercially available text editors, such as Microsoft Word, Chado SpellEditor, and Tx Text Control.
[0070] In the Chado SpellEditor, an API command instruction that may be used to select inserted text is “SetSelection(*)”, and an API command instruction that may be used to convert selected text into a hyperlink is “SelectionIntoLink(*)”. When a user clicks on a hyperlink created in this manner, SpellEditor calls the function “LinkClicked” to handle the input event. In the current version of SpellEditor, the SelectionIntoLink(*) command is only effective during the editing process, and the hyperlinks created during this time are lost when the file is saved. To remedy this, the wrapper may include additional instructions to scan through a text data file to detect instances of the time codes, and to convert each detected instance to a hyperlink with a call to SelectionIntoLink(*). These instructions can be included in the wrapper's instructions that handle the opening of the text data files. Other text editors, such as Tx Text Control, allow hyperlinks to be inserted in HTML formal into the text file by an API command instruction, which allows a greater flexibility in inserting the hyperlink and in executing it when it is clicked. After first describing some relatively simple hyperlink embodiments, more preferred hyperlink embodiments are described.
[0071] Input events, such as the link-clicked event, are part of the well-known input-handling framework for object-oriented software. In this framework, processor 110 runs various tasks that are related to one another in a parent-child manner. For example, the operating system is a central parent task to all other tasks, and the wrapper is a child task of the operating system. In turn, the instances of the media player and the text editor are child tasks to the wrapper. In the input-handling framework, the programmer assigns various input events to the child task for it to detect, and provides handling instructions for each of the assigned input events. Input events include single mouse clicks on menu tabs and buttons, double mouse clicks on menu tabs and buttons, keystrokes, hot-keys, link-clicked, etc. The handling instructions for an assigned input event may direct the child task to use the detected input event for its own purposes, or may direct the child process to pass the detected input to its parent task or to the operating system (e.g., Windows event handler) for use. If the child task has children tasks of its own (such as the wrapper), the handling instructions for an assigned input event may direct the child task to pass the detected input event to one of its child tasks. As a default, unassigned events may be passed to the task's parent. In the exemplary embodiment discussed here, the wrapper preferably handles input events occurring in areas 230 and 240 ( FIG. 4A ) itself, and also handles hot-key events occurring in container 200 (such as insertions of time stamps by use of the Ctrl-T keystroke combination and insertions of class members by use of the function keys). Except for the hot-key events, input events occurring in area 220 are passed to the text editor for handling, and input events occurring in area 210 are passed to the media player for handling. When a link-clicked event occurs in the text editor instance, the text editor instance is configured to pass the event to the wrapper for handling. Most commercially available text editors have API command instructions that enable a calling program (such as the wrapper) to set this configuration.
[0072] When a user clicks on a time-stamp hyperlink in the text data file, the text editor detects the link-clicked event and passes the hyperlink information, including the time code, to the wrapper for handling. The wrapper examines the hyperlink to determine if it is a time-stamp hyperlink, or another type of hyperlink. Prior to this, the wrapper coordinated the media player and the text editor to process respective files that are related to the same underlying media asset. Thus, if the wrapper determines that the hyperlink was a time-stamp hyperlink, the wrapper can immediately issue an API command to the media player to set its current playing time to the time code that was given to it by the link-clicked event. If the wrapper determines that the passed hyperlink is of another type, it may ignore it or it may pass the hyperlink to an event handler of the operating system, which can then consult a registry to determine which browser program to start and pass the hyperlink to the browser program, for handling.
[0073] In the above example, the wrapper coordinates the media player and the text editor to process respective files that are related to the same underlying media asset. In this case, the hyperlink that is passed between the text editor and the wrapper need only contain the time code since the wrapper already knows which media file the time code refers to. Thus, the filename of the media file need not be included in the hyperlink, and the hyperlink is in the form of an implicit relative link. However, it may be appreciated that the hyperlink may contain the filename of the media file to which the time code refers, and that the filename may be inserted into the text data file along with the time code by one of the API command instructions to the text editor discussed above. This would result in an explicit relative hyperlink. When this hyperlink is clicked on and passed to the wrapper by the text editor, the wrapper may examine the filename to ensure that the media player is playing the same media file as indicated by the filename before directing the media player to set its current playing position to the hyperlink's time code. If the media player is not playing the media file indicated by the filename passed by the hyperlink, the wrapper can include instructions to search the current working directory for the media file, and direct the media player to load the media file before directing the media player to go to the time code indicated by the hyperlink. To facilitate this searching, the hyperlink may include the directory location of the filename in the file system or the network address of the file (if it is accessible over a communications network).
[0074] Some text editors have API command instructions that direct the text editor to insert an HTML-formatted text string into the text data file at the current cursor position. When receiving such a command, the text editor interprets the text string according to the HTML syntax, and then generates a corresponding representation of the text string in its internal data structure. Some text editors also have API command instructions that allow a programmer to insert a hyperlink directly into the text data file at the current cursor position, such as in the form of an object. In both of these types of commands, the programmer can typically configure the appearance of the hyperlink to show only the time code on the text editor screen, while hiding the full address of the hyperlink from view. For example, a programmer could use such an API command to effectively insert the following HTML-formatted hyperlink at the current cursor position in the text data file:
[0075] <a href=“\\fileserver\MediaDirectory\MediaFile.mpg?00:20:13:05”> 00:20:13:05 </a>
[0000] which would be displayed on the text-editor screen as: 00:20:13:05, and would have the hyperlink address of “\\fileserver\MediaDirectory\MediaFile.mpg”, with the time code appended to the hyperlink address as a parameter, and with both the hyperlink address and parameter being hidden from view in area 220 . According to the HMTL-language standard, the hyperlink is started with the tag <a>, and ended with the tag <a/>. Text that appears between these two tags will be printed on the screen in hyperlink form (underlined, with the text set optionally set in a different color than non-hyperlink text).
[0076] In the above examples of HTML hyperlink timestamps, the filename of the media file and playing position with the medium have been specified by the filename's path within the File System, and a position parameter, respectively. As another and more flexible option, this information may be specified in the hyperlink as a function call, with the filename and playing position provided as arguments to the function (an in turn the program jump). As will become apparent below, this enables the filename and playing position to be encoded or encrypted (preferably encrypted) with a key that may be assigned to a particular user or team of users. This can be used to provide added degrees of security, as discussed below. The function-call form of the hyperlink can take many forms, four examples of which are shown below:
<a href=“javascript:jump(‘position’)”>HH:MM:SS:FF</a> <a href=“javascript:jump(‘filename’, ‘position’)”>HH:MM:SS:FF</a> <a href=“javascript:jump(‘encrypted_position’)”>HH:MM:SS:FF</a> <a href=“javascript:jump(‘encrypted_filename’, ‘encrypted_position’)”>HH:MM:SS:FF</a>
where <a href=“”> is the HTML starting tag for the hyperlink, </a> is the ending tag for the hyperlink, “javascript:jump( )” is a function call to a program written in JavaScript, “position” is the playing position in the media file (e.g., the position specified in decimal format where each whole number is one second of playing time), “filename” is the media file's filename in the File System, and where “encrypted_position” and “encrypted_filename” are encrypted or encoded versions of the position and filename, respectively. When the hyperlink is activated, it gets passed to the wrapper, where the jump function resides. If both the filename argument and the position argument have been passed to the wrapper, then the wrapper calls the jump function using a JavaScript engine/execution unit. If only the position argument has been passed, then the wrapper provides the current working file as the filename argument to the jump function, along with the position argument that it received from the handler that passed the hyperlink to it (e.g., the text editor). In turn, the jump program sends commands to the media player to cause it to open the specified file if not already opened, and to jump to the playing position specified by the position argument.
[0081] If the filename and position are encrypted, then they are decrypted at an appropriate time during the handling of the hyperlink. For example, the filename and position may be decrypted or decoded by the wrapper using an assigned key before the wrapper passes the arguments to the jump function. The allows all of the hyperlink timestamps to be encrypted or encoded so as to prevent a third party from finding the locations of the media files on the Internet (if the media files are stored in that manner) should the text file having the hyperlink timestamps be intercepted or otherwise found by the third party. As another example, such as when the media files are stored at a central database fileserver accessible over the Internet, the filename may be passed in encrypted or encoded form to the fileserver, which may then transmit the file to the wrapper over a secure channel. In this case, the decryption or decoding of the encrypted filename is done at the central database file server using the assigned key, or an assigned companion key. Currently, the Advanced Encryption Standard (AES) is preferred, but other encryption methods may be used. As another advantage of encrypting the filename, the text file may be viewed using a web browser (under the control of the wrapper) instead of a text editor, and the encryption provides additional security for this mode of operation.
[0082] For HTML hyperlink timestamps, it is advantageous to prevent the user from being able to edit the hyperlink. Many HTML-base text editors have the capability to prevent editing of specific portions of an HTML file using the Span tags and an attribute that turns off editing. For example, the TxText Control editor has the attribute contentEditable, which enables the editor to change HTML text when contentEditable is set to a true value, and which prevents the editor from changing HTML text when it is set to a false value. Thus, to prevent an HTML hyperlink timestamp from being edited by the user, the wrapper may insert the following HTML tag before the HTML text for the hyperlink: <span contentEditable=false>, and the following HTML tag afterwards: </span>.
[0083] If the text editor can be configured by API command instructions to pass the handling of a link-clicked event on a hyperlink to the wrapper, the wrapper will receive both the filename and directory location of the media file, as well as the time code. The wrapper may then confirm that the media player is playing the media file indicated in the hyperlink before instructing the player to seek the frame corresponding to the time code specified in the hyperlink. If the media player is not playing the media file indicated in the hyperlink, the wrapper may then issue API commands directing the media player to close the existing media file and to open the media file indicated by the hyperlink (e.g., \\fileserver\MediaDirectory\MediaFile.mpg), and thereafter seek the frame corresponding to the time code that is provided as a parameter. This type of hyperlink is an absolute hyperlink, and it enables a single text data file to contain logging and transcription from two or more media files, which can be useful in constructing storyboard documents from multiple media files. The ability to include logging and transcription from multiple media files can also be achieved using hyperlinks that only provide a filename and a time code, such as:
<a href=“MediaFile1.mpg?00:20:13:05”> 00:20:13:05 </a> <a href=“MediaFile2.mpg?01:00:53:24”> 01:00:53:24 </a>.
In this case, the wrapper can comprise instructions that direct data processor 110 (as configured by the user or the programmer) to search one or more preselected directories for the media files MediaFile1.mpg and MediaFile2.mpg.
[0086] If the text editor cannot be configured by API command instructions to pass the handling of a link-clicked event on the hyperlink to the wrapper, the text editor will generally pass the handling of the link-clicked event to the operating system's event handler. The operating system's event handler typically has a registry that assigns the handling of hyperlink types and file types to specific programs, such as Microsoft's Internet Explorer for *.html files and Adobe's Acrobat for *.pdf files. The associations in the registry can be changed by the user through an operating system interface, and by a programmer (and a wrapper) through API command instructions to the handler tor the registry. In one embodiment, the wrapper can have API command instructions to this handler to change the association for *.mpg files in the registry to indicate that the wrapper is to handle these files. With this change, the operating system's event handler will then pass the handling of the hyperlink to the currently running instance of the wrapper. The wrapper may then receive the hyperlink and process it as previously described. Upon exiting the wrapper program, the wrapper preferably has instructions that will change the association of the media files in the registry back to the initial configuration.
[0087] To avoid modifying the registry in the above manner, the following protocol can be used to structure the instruction sets. For each media file, a place-holder file with a unique file extension (such as “.wrp”) can be created by the wrapper for each media file handled by the wrapper, and the registry may be modified to associate the handling of these files with the wrapper. Instruction sets in the wrapper, executed during the creation of a text data file, may accomplish these tasks. For example, a place-holder file could be named “MediaFile1.mpg.wrp” for the media file “MediaFile1.mpg.” The file may be a zero-byte file, or may contain the filename of the media file. The wrapper may then enter hyperlinks into the text editor in a form that uses the place-holder file, such as
[0088] <a href=“MediaFile1.mpg.wrp?00:20:13:05”> 00:20:13:05</a>
[0000] When this hyperlink is passed to the operating system's event handler, the registry directs the operating system to pass the handling of the hyperlink to the current running instance of the wrapper. When the wrapper receives the request to handle the hyperlink, it contains instructions that extract the filename of the media file from the link (e.g, removing “.wrp” from the name of the place-holder file), and then process the hyperlink as previously described.
[0089] Both relative hyperlinks and absolute hyperlinks may be readily incorporated into the same text data file. For example, the hot-key sequence “Ctrl-T” may be used to enter a relative time-stamp hyperlink, and the hot-key sequence “Shift-Ctrl-T” may be used to enter an absolute time-stamp hyperlink. The wrapper may then comprise handling instructions for each of these input events. Also, the wrapper can have a default setting for the insertion of hyperlinks that can be set by the user. The default can be set to relative mode, implicit relative mode, or absolute mode, and once set, all inserted hyperlinks will be according to the default setting, unless explicitly overridden by a specific user input command. In addition, the wrapper may include another set of instructions that converts all time-stamp hyperlinks to absolute time-stamp hyperlinks, or to relative time-stamp hyperlinks, or to implicit relative time-stamp hyperlinks. In order to incorporate time stamps related to another media file, another instance of the wrapper may be started and opened to the text data file for the other file. Text from that file may be copied and pasted into the primary working instance of the wrapper. The time-stamp hyperlinks so copied are preferably in absolute form. As yet another approach, the wrapper may have a set of instructions, activated by a menu selection of the “File” tab in area 230 , to open an alternative media file that is not correlated to the text data file. Text and absolute time-stamp hyperlinks may then be inserted into the text data file from the alternative media file.
[0090] The wrapper may further comprise a set of instructions that directs data processor 110 to detect a preselected input command from the user interface requesting to send the data file by e-mail, and to present the user with a dialog input box that enables the user to provide or select an e-mail recipient. The instruction set further directs the data processor to e-mail the data file to at least one recipient indicated by the user. In a similar manner, the wrapper may further comprise a set of instructions that directs the data processor to detect a preselected input command from the user interface requesting to send the data file by file-transfer protocol, and to present the user with a dialog input box that enables the user to provide or select a destination for the data file. The instruction set further directs data processor 110 to transfer the data file to the network address of the destination indicated by the user. With this, one can provide a method of enabling a user to receive a digital medium in stream or file form over a communications network, generate a data file with a description of the digital media, and thereafter to send it to a designated location or person over the communications network. The method may further include the sending of the digital media with an indication of the time period (e.g., turn-around time) in which the description is to be generated.
[0091] Scene Editor Multipurpose Player. As indicated above, the ability to place timestamp hyperlinks into a text data file enables producers, storywriters, and other production staff to easily create scene sequences and storyboards in text data files, where the scene clips can be played from the text data files by clicking on the timestamp codes for the scenes. Additional related inventions of the present application provide users with a scene editor and a storybook editor that enable a user to formally construct scene sequences and storyboards, which can, then be exported as Edit Decision Lists (EDLs). The Scene Editor enables a user to create, edit, play and delete audio scenes and video scenes (both being generally referred to as scenes) that are stored on a File System (such as a file server, file database, and the like). Each scene is comprised of one or more media clips, each media clip being a portion of a respective base media file that is identified by a starting time point and an ending time point. The scene editor allows a user to directly specify the clip of a base media file as a clip in a scene, and also allows a user to import a clip from a previously-created text data file, which may be a logging file or a transcription file. Occasionally, a clip may also be the entire base media file, in which case the starting time and ending time points of the clip are those of the base media file. In a typical situation, the user opens a new scene or opens a previously created scene, adds new clips to the scene, deletes unwanted clips, and possibly rearranges the playing sequence of the clips in the scene. The storybook editor enables a user to organize the scenes into acts and episodes (an episode comprising one or more acts). An instance of the scene editor may be called from the storybook editor to edit a scene of the storyboard, as selected by the user.
[0092] Preferred embodiments of the scene editor and the storybook editor provide a dependent instance of a media player, and can play clips, scenes, acts and episodes (as the case may be) according to requests by a user. Each scene editor and each storyboard editor can be run on the configuration shown for multipurpose player 100 in FIG. 1 , but with each having a respective group of instruction sets. In preferred embodiments, each comprises a wrapper of instruction sets, which call a dependent instance of a media player (which may not be needed for some embodiments of the storybook editor). In further preferred embodiments, each wrapper is downloadable into a web browser and is executable by the web browser. Exemplary scene editors according to the present application are described first, followed by a description of the storyboard editor. The tasks of each will be described, where each task or group of tasks can be implemented by a respective set of instructions that direct a data processor (e.g., processor 110 ) to perform the corresponding task(s). In view of the present description, it will be well within the ability of one of ordinary skill in the computer arts to construct these instruction sets without undue experimentation.
[0093] Exemplary scene editors according to the present invention comprise a main viewing page that lists all of the user's scenes, an example of which is shown in FIG. 6 . The screen presents a list of scenes available to the user, with each scene entry providing the name given to the scene by the user, the dates on which the scene was created and last modified, and navigation buttons that allows the user to page through the available scenes, and to search the name fields of the available scenes. This part of the scene editor may be implemented by a respective set of instructions that accesses a File System for the user's scene files, navigates through the files, and searches the file names. In preferred embodiments, this part of the scene editor is implemented as a web page that is presented to the user, with the web page being generated by a file server that holds the user's scene files in a File System. This allows the user to log into the system from anywhere in the world, and work.
[0094] To view the details of a scene, the user can double-click on the name of the scene in the screen shown in FIG. 6 . The scene's name is preferably a hyperlink, which causes a new screen page to load in a browser window with the scene's details in a view screen. An example of this view screen is shown in FIG. 7 . It comprises “Edit,” “Copy,” “Export,” and “Delete” task buttons at the top of the screen, and the name of the scene immediately below (“Westwind_EDL” in this example). The view screen further comprises a display area 210 in which the media player is presented, as previously described above, and a display area 320 to show a scene-clips list. Display area 320 comprises a window that displays the clips of the scene, a “Play Scene Sequence” button, and a “Comment” button. For each clip entry, the scene-clips list shows the filename of the base media file from which the clip originated, the starting time point of the clip in the base media file, the ending time point in the base media file, and a user-editable comment field. A clip can be played by the player by double-clicking on its entry in the scene-clips list. Any clip may be highlighted by clicking on it. The “Comment” button enables the user to edit the comment field of a highlighted clip, and the “Play Scene Sequence” button enables the user to have the media player play the scene from start to finish in display area 210 . Once the player starts to play the scene sequence, the user may stop the player at any point by clicking a “Quit Scene Playing mode” button, which may appear in the same location as the “Play Scene Sequence” button when the player is playing the scene. Also shown in display area 320 is a “Media Files:” entry box to enable the user to select a base media file, a “Play” button to enable the user to have the media player play the base media file in display area 210 , and a “Select Episode:” entry box to enable the user to select an Episode from which to choose a base media file. (In preferred embodiments, the base media files are grouped according to Episodes, which can be thought of as file directories.) Each scene has a data file associated with it that stores the above information about the scene and about its clips, and this file is accessed upon entering the view screen and display, as indicated above.
[0095] The part of the scene editor that provides the view screen may be implemented by a respective set of instructions that accesses the File System for the scene's data file, displays the information of the scene in the above manner, enables the user to edit a comment (and to save this information to the scene's data file, to play a highlighted clip in response to a double-click on the highlighted clip, and to play the entire scene sequence in response to the user clicking on the “Play Scene Sequence” button. To play the scene sequence, the instructions can perform the following tasks: loading the information about the clips in the scene's data file into sequentially ordered data structures (e.g., objects), one object per clip, and sequencing through the data structures one after the next, with each sequencing including issuing a play command to the media player to play the base media file indicated in the data structure beginning at the starting time point indicated in the data structure, monitoring the playing position of the media player until the media player reaches the ending time point indicated in the data structure, and then moving to the next data structure in the sequence. In preferred embodiments, this part of the scene editor is implemented as a web page that is presented to the user, with the web page being generated by a file server that holds the scene's data files in a File System. This allows the user to log into the system from anywhere in the world, and work.
[0096] Referring to the top of the view screen in FIG. 7 , the user may edit the scene by clicking on the “Edit” button, may copy the scene to a new scene by clicking on the “Copy” button, export the file to an Edit-Decision-List (EDL) file by clicking on the “Export” button, or delete the file by clicking on the “Delete” button. Clicking each of these buttons causes the screen editor to execute respective sets of instructions that carry out the above tasks. Of these four, the “Edit” button and the “Export” button are described in greater detail. The copy and delete tasks are straightforward file management tasks that only involve changes to the File System, and do not require any more detail for one of ordinary skill in the art to implement.
[0097] Export Mode. Clicking on the “Export” button in the view screen causes a segment of code to be executed that generates an EDL file from the information in the scene's data file. An example of the EDL file is shown in FIG. 8 . The EDL file may be provided in a number of formats, including plain text (as shown in FIG. 8 ), HTML, XML, and MFX. The part of the scene editor that provides the export task may be implemented by a respective set of instructions that accesses the File System for the scene's data file, generates the EDL description in a desired format, saves the format to another file in the File System according to user direction, and displays the generated EDL file in a display window for confirmation by the user, followed by returning to the view screen.
[0098] Edit Mode. Clicking on the “Edit” button in the view screen brings up the edit screen for the scene last viewed in the view screen. The Edit button is preferably a hyperlink, which causes the edit screen to load in a browser window with the scene's details. An example of the edit screen is shown in FIG. 9 . It comprises “Save” and “Import” task buttons at the top of the screen, and the name of the scene immediately below (“Westwind_EDL” in this example). The view screen further comprises a display area 210 in which the media player is presented, as previously described above, and a display area 320 to show a scene-clips list, as previously described. It also presents a preparation list in a display area 330 where the user can create new clips from a base media file (as previously described above), and can add the new clips to the opened scene. Clips are initially prepared from base media files in the preparation list, and then transferred to the scene-clips list. The part of the scene editor that provides the edit screen may be implemented with the same instructions to execute common tasks used for the view screen, plus instruction sets that execute the further tasks described below. In preferred embodiments, this part of the scene editor is implemented as a web page that is presented to the user, with the web page being generated by a file server that holds the scene's data files in a File System. This enables the user to log into the system from anywhere in the world, and work.
[0099] For each of its clip entries, the preparation list shows (in display area 330 ) the starting time point, the ending time point, and a user-editable comment field, which the user may use to give the clip a meaningful title or identifier. Associated with the preparation list are: a text dialog box for the user to select a base media file from which to make new clips (which was described above), a “New” button to enter a new clip from the selected base media file as a new entry in the preparation list (with the time points placed in a “not set” state), and a “Delete” button to delete a clip from the preparation list that has been previously highlighted. A user can highlight a clip for deletion or other processing (as described below) by clicking once on its entry in the preparation list. When a new clip is entered into the preparation list with the “New” button, the filename and File-System location (e.g., directory) of the base media file from which the clip is taken are associated with the entry, but are not shown in the preparation list. However, the filename will be shown in the scene-clips list when the clip is transferred (as described below in greater detail). A clip can be played by the player by double-clicking on its entry in the preparation list. The base media file can be loaded into the player and played by clicking on the “Play” button to the right of the dialog box for the base media file (as described above). This part of the scene editor may comprise instruction sets that respond to the user's clicking of New button to create a new clip using the opened base media file, that create data structures for each newly added clip and update the data structure with the filename of the base media file, that display the contents of the data structure of clips of the preparation list in display area 330 , that highlight a clip of the preparation list when a user single-clicks on it, that instruct the media player to play the clip in display area 210 when the user double-clicks on the clip's entry, and that delete a highlighted clip in response to the user clicking the “Delete” button. The data structures for the clips in the preparation list are maintained in a sequential order by the data structures themselves (e.g., linked-list structure) or by an index structure (e.g., pointer array). The same data structures may be used to manage the clips presented in the scene-clips list, and are initially filled upon accessing the data file for the scene.
[0100] Further associated with the preparation list are: a “Set Start” button to allow the user to set the starting time point of a highlighted clip, a “Set End” button to allow the user to set the ending time point of a highlighted clip, and a “Comment” button to allow the user to provide or edit the text of a comment field for the highlighted clip. The comment field is updated in the same way as described above, and similar instructions may be used. A user may set each time point by first highlighting the clip, then clicking either the “Set Start” button or the “Set End” button, as the case may be, which will bring up a dialog box for the user to enter the hour, minute, second, and frame information for the starting point, or for the user to click a button on the dialog box which copies the current position location of the media player (as shown in display area 210 ) into the dialog box. Having done this, the user may click a “Save” button on the dialog box, which updates the data structure for the clip to reflect the new time point information, or may click a “Cancel” button to escape out of the process without setting the time point. The media player preferably provides precise step control buttons 280 to enable the user to step forward or backward in the base media file from a paused position beforehand in order to find a desired starting or ending point for the clip, as the case may be. This part of the scene editor may comprise instruction sets that respond to the user's inputs on the buttons and clip entries to open up dialog boxes, receive information by way of the dialog boxes, and update the data structures for the clips in the preparation list. In addition, this part of the scene editor may comprise the previously-described set of instructions that obtains the current playing position of the media player so that the current playing position of the media file may be input as a starting or ending time point.
[0101] Clips in the preparation list can be moved (transferred) to the scene-clips list by highlighting the clip's entry in the list, and then clicking the left transfer button 341 . Multiple entries can be highlighted and transferred as a group. If a clip is highlighted in the scene-clips list (the receiving list), the clips being transferred from the preparation list will be inserted before (above) the highlighted clip in the scene-clips list. If no clip is highlighted in the scene-clips list (the receiving list), then the clips being transferred from the preparation list will be added to the end of the scene-clips list. Clips in the scene-clips list can be moved (transferred) to the preparation list by highlighting the clip's entry in the list, and then clicking the right transfer button 342 . When a clip is transferred, the associated filename and File-System directory of its base media file are transferred as well. This part of the scene editor may comprise instruction sets that respond to the user's inputs on buttons and 341 and 342 and the highlighting of clip entries in both of the lists, and updating the sequential orderings of the data structures for both lists according to the user's inputs, and thereafter updating the display areas 320 and 330 to reflect the results of the transfers.
[0102] In edit mode, the Scene Editor also enables the user to move clips around within the scene-clips list to change the playing sequence of the clips. This is done by highlighting the clip that is to be moved, and then clicking the up or down buttons 351 and 352 to move the highlighted clip to the desired position in the scene-clips list, with each click of the up or down button moving the highlighted clip up or down by one entry. This part of the scene editor may comprise instruction sets that respond to the user's inputs on buttons 351 and 352 and the highlighting of clip entries in the scene-clips list, and updating the sequential order of data structures for the scene-clips list according to the user's inputs, and thereafter updating the display areas 320 and 330 to reflect the moves.
[0103] A “Save button” is provided at the top of the Edit-mode screen to permit the user to save the edits made to a scene. An instruction set detects the click of the save button by the user, and in response thereto saves the information held by the data structures for the scene-clips list to the data file for the scene. Any information in the preparation list is lost.
[0104] Import Mode. From Edit mode, the user can add clips to the preparation list based on the time codes in a transcription data file, log data file, notes data file, or other type of data file. By clicking on the “Import” button in the edit-mode screen ( FIG. 9 ), the user will open up a dialog box that will enable a text data file to be selected for importation. The user then double-clicks, or otherwise selects, a data file for importation. Next, a viewing window will appear showing the contents of the data file, an example of which is shown in FIG. 10 . If a user clicks on any of the time codes of the data file, a secondary dialog box will appear, as shown in FIG. 11 , asking if the user would like to enter a clip starting at the selected time code, and ending at the next time code in the data file. If the user answers OK, the clip will be imported into the preparation list, with the comment field for the clip typically being idled with the text that appears between the two time codes, up to a set limit of characters (e.g., 64 characters). If the last time code in the data file is clicked, then the ending time code will not be set during the importation process, and the user will have to manually set an ending time code before transferring the clip from the preparation list to the scene-clips list. As a feature, an “Import All” button is provided on the viewing window to allow the user to import all of the time codes of the data file into the preparation window. This part of the scene editor may comprise instruction sets that respond to the user's request to open a text data file, that open the requested data file in a web page, that respond to a user clicking on a timestamp hyperlink and find the time code of that hyperlink and the time code of the next timestamp hyperlink in the file (or setting a blank value if none is found), that present a secondary dialog box showing the start and end times of the clip to be imported with a query to the user to either OK the importation of the clip to the preparation list or escape from the importation, and that enter a new data structure for a clip in the preparation list if the user approves of the importation. The latter task uses the two time codes as the starting and ending time points for the newly added clip, and the text between the two timestamp hyperlinks as the comment field for the clip. In addition, the scene editor comprises instructions that are responsive to a user clicking on the “Import All” button, and that perform the above steps in tandem for all of the timestamp hyperlinks found in the text data file.
[0105] The above instruction sets that direct a data processor (such as processor 110 ) to perform the above tasks of the scene editor are illustrated in FIG. 12 as being embodied on a computer-readable media. All of the computer-readable mediums disclosed herein and recited in the claims cover all forms from which a data processor may read the instructions to perform the tasks. Exemplary medium include, but are not limited to, disk drives, tape, volatile memory, non-volatile memory, CDs, DVDs, bit streams transmitted over networks, the Internet, and the like.
[0106] Storyboard Editor. The ability to enable a user to easily compose scenes from base media files will create a need for the user to readily organize the composed scenes into acts and episodes, with each episode comprising one or more acts. It may be appreciated that the term “episode” may go by other names, such as “story” or “segment,” and that the term “act” may also go by other names. As indicated above, a storyboard can be run on the configuration shown for multipurpose player 100 in FIG. 1 , but with a different group of instruction sets. In preferred embodiments, the storybook editor comprises a wrapper of instruction sets, which may call a dependent instance of a media player as an option. In further preferred embodiments, the storybook editor is downloadable into a web browser. The tasks of an exemplary storybook editor are described below, where each task is implemented by a respective set of instructions that directs a data processor (e.g., processor 110 ) to perform the corresponding tasks. In view of the present description, it will be well within the ability of one of ordinary skill in the computer arts to construct these instruction sets without undue experimentation.
[0107] Exemplary storybook editors according to the present invention comprise a main viewing page that lists all of the user's scenes, an example of which is shown in FIG. 13 . The screen presents a list of storybooks available to the user, with each storybook entry providing the name given to the storybook by the user, the dates on which the storybook was created and last modified, and navigation buttons that allow the user to page through the available storybooks, and to search the name fields of the available storybooks. It also provides a “Create New” button that enables the user to add a new storybook to the user's list, and a “Delete” button (not shown) to enable a user to delete a highlighted storyboard. This part of the storybook editor may be implemented by a respective set of instructions that accesses a File System for the user's storybook files, navigates through the files, and searches the file names. In preferred embodiments, this part of the storybook editor is implemented as a web page that is presented to the user, with the web page being generated by a file sewer that holds the user's storybook files in a File System. This allows the user to log into the system from anywhere in the world and work.
[0108] To view the details of a scene, the user can double-click on the name of the scene in the screen shown in FIG. 13 . The storybook's name is preferably a hyperlink, which causes a new screen page to load in a browser window with the storybook's details in a storybook view screen. An example of this storybook view screen is shown in FIG. 14 . It comprises “Edit” and “Delete” task buttons at the top of the screen, and the name of the scene immediately below (“Sample Story” in this example). The storybook view screen has a display area showing a table of rows and columns, where each column is an episode of the storybook, the top row lists the episodes by name, and each row below that is capable of storing a respective act for each episode. That is to say, each cell below the top row of the table is capable of storing an act of an episode. Not all episodes have the same number of acts, but for television productions, the forgoing is a common occurrence. Further, each cell of the display area is capable of storing one or more scenes, such as those composed by the above-described scene editor, with the one or more scenes comprising the act represented by the cell. Within each cell, the total running time of all the scenes of the cell is shown. For television productions, this helps the user to match the running times of each act to the allocated programming segments in the broadcast. In the top row, the production team for the episode and the running time of the episode are given along with the name identifier of the episode. Each episode's name identifier (or title) and team name is editable by the user, and the total running time of the episode is computed as the total running times of the episode's acts.
[0109] The information presented in the table display area is found in the data file for the storybook. This data file stores the number, names, and production teams of the storybook episodes, the number of acts in each episode, and optionally the running time of each episode. Also, for each act, the data tile stores the names and filenames (including directory locations) of the scenes that are assigned to each act, and optionally the total running time of each act. The storage of the running times of the acts and episodes is optional since the running times can be computed by examining the data files of the scenes of the acts in the storybook, and the running times of the episodes can be computed from the running times of their respective acts. This part of the storybook editor that provides the storybook view screen may be implemented by a respective set of instructions that accesses the File System for storybook's data file, reads the data file for the episodes and acts of the storybook, and displays this information in the above table form. The instructions may further include computing the running time of each act by accessing the data files for the scenes of each act, computing the miming time of each scene from the starting and ending time points of the clips of each scenes, and totaling up the running times of each act's scenes to provide the running time of the act; and instructions for computing the running time of each episode from the running times of its acts.
[0110] Referring to the top of the storybook view screen in FIG. 14 , the user may edit the storybook by clicking on the “Edit” button, or delete the storybook by clicking on the “Delete” button. Clicking each of these buttons causes the storybook editor to execute respective sets of instructions that carry out the above respective tasks. Of these, the “Edit” button is described in greater detail. The delete task is a straightforward file management task that only involves a change to the File System, and does not require any more detail for one of ordinary skill in the art to implement it.
[0111] Clicking on the “Edit” button in the storybook view screen of FIG. 14 brings up the storybook edit screen for the storybook. The Edit button is preferably a hyperlink, which causes the edit screen to load in a browser window with the scene's details in a form that enables editing. An example of the edit screen is shown in FIG. 15 . It comprises “Add Episode”, “Add Act”, “Save”, and “Delete” task buttons at the top of the screen, the name of the storybook immediately below (“Sample Story” in this example), and the table view of the storybook below that. The information presented in the table is contained in the data file for the storybook, which is loaded into internal data structures (e.g., software objects) of the storybook editor, and displayed on the edit screen therefrom. The user can add a new episode to the story by clicking on the “Add Episode” button; the new episode will be added to the internal data structure and displayed after the rightmost column of the table with a default name, such as “Episode X,” where X is the total number of episodes in the storybook. The user can double-click on an episode's name to change it, and can also double-click on an episode's production-team field to provide the name of the production team for the episode, if appropriate. The production-team field is initially set to a default value, such as “Team,” upon creation of the episode. The internal data structures are changed to reflect the user's changes. When an episode is added, the cells for its acts are placed in blank states. The user can add a new act for all of the episodes by clicking on the “Add Act” button; this adds a new act row to the internal data structures and is displayed on the screen at the bottom of the table. An episode can be deleted by clicking on the “x” button in the top cell of the episode, and a row of acts can be deleted by clicking on the “x” button in the leftmost cell of the row. The internal data structures are updated to reflect the deletions. The part of the storybook editor that provides the edit screen may be implemented with the same instructions used for the view screen that execute common tasks, plus instruction sets that execute the tasks of receiving user input on making additions, deletions, and changes to the above elements of the storybook table, updating the internal data structures for the table in response to the user's inputs, and displaying updates to the table on the edit screen. In preferred embodiments, this part of the scene editor is implemented as a web page that is presented to the user, with the web page being generated by a file server that holds the storybook's data file in a File System. This enables the user to log into the system from anywhere in the world, and work.
[0112] Within each act cell, a “+” button is provided to enable the user to add a scene to an act. By clicking on this button, the user brings up a dialog box that allows the user to select a scene from the user's available set of scenes. An example of this is shown in FIG. 16 , where a first input box is provided to enable the user to select a scene file in the File System, and a second input box is provided to allow the user to enter a description of the selected scene, the description of which will be displayed in the corresponding table cell and will be stored in the internal data structure of the table. For each act cell, the data structures are able to maintain a list of scenes (and their sequence) that have been assigned to the cell by the user. This part of the storybook editor may be implemented with instruction sets that execute the tasks of receiving user input of adding a scene, updating the internal data structures for the table in response to the user's inputs, and of displaying updates to the table on the edit screen. Also within each act cell, an “E” button is provided next to each scene to enable the user to edit the corresponding scene with the above-described scene editor. The “E” preferably comprises hyperlink that causes a web page implementation of the scene editor to be loaded into a new browser window with the scene editor set to work on the scene to which the “E” button corresponds. As another approach, the “E” button may launch a new child process that runs an instance of the scene editor in a new window of the operating system, with the scene editor set to work on the selected scene.
[0113] Referring back to FIG. 15 , when a user is done editing a storyboard, the storyboard may be saved by clicking on the “Save” button at the top of the storybook edit screen. In response to clicking the “Save button,” the storybook editor executes an instruction set that updates the data file for the storybook with the contents of the internal data structures. Also provided in the edit screen is a “delete” button to enable the user to delete the storyboard altogether.
[0114] The above instruction sets that direct a data processor (such as processor 110 ) to perform the above tasks of the scene editor are illustrated in FIG. 17 as being embodied on a computer-readable medium. All of the computer-readable mediums disclosed herein and recited in the claims cover all forms from which a data processor may read the instructions to perform the tasks. Exemplary media include, but are not limited to, disk drives, tape, volatile memory, non-volatile memory, CDs, DVDs, bit streams transmitted over networks, the Internet, and the like.
[0115] While the present inventions have been particularly described with respect to the illustrated embodiments, it will be appreciated that various alterations, modifications and adaptations may be made based on the present disclosure, and are intended to be within the scope of the present inventions. While the inventions have been described in connection with what are presently considered to be the most practical and preferred embodiments, it is to be understood that the present inventions are not limited to the disclosed embodiments but, on the contrary, are intended to cover various modifications and equivalent arrangements included within the scope of the appended claims. | Disclosed are Multipurpose Media Players that enable users to create transcriptions, closed captions, and/or logs of digitized recordings, that enable the presentation of transcripts, closed captions, logs, and digitized recordings in a correlated manner to users, that enable users to compose one or more scenes of a production, and that enable users to compose storyboards for a production. The multipurpose media players can be embodied within Internet browser environments; thereby providing high availability of the multipurpose players across software platforms, networks, and physical locations. | 6 |
BACKGROUND OF THE INVENTION
[0001] Soap bars for cleansing, are typically prepared by saponification/neutralizing triglyceride/fatty acids. In this saponification process, various fats (e.g., tallow, palms and coconut oil blends) are saponified in the presence of alkali (typically NaOH) to yield alkaline salts of fatty acid (derived from the fatty acid chains forming the glyceride) and glycerol. Glycerol is then typically extracted with brine to yield dilute fatty acid soap solution containing soap and aqueous phase (e.g., 70% soap and 30% aqueous phase). The soap solution is then typically dried (e.g., to about 12% water) and the remaining, mass is milled, plodded and stamped into bars. Alternatively, the soap solution can be cast in to moulds, blisters etc.
[0002] The chain length of fatty acid soaps varies depending on starting fat or oil feedstock (for purposes of this specification, “oil” and “fat” as used interchangeably, except where context demands otherwise). Longer chain fatty acid soaps (e.g., C 16 palmitic or C 18 stearic) are typically obtained from tallow and palm oils, and shorter chain soaps (e.g., C 12 lauric) may typically be obtained from, for example, coconut oil or palm kernel oil. The fatty acid soaps produced may also be saturated or unsaturated (e.g., oleic acid).
[0003] Typically, longer molecular weight fatty acid soaps (e.g., C 14 to C22 soaps) are insoluble and do not generate foam, despite the fact that they can help making the foam generated by other soluble soaps creamier and more stable. Conversely, shorter molecular weight soaps (e.g., C 8 to C 12 ) lather quickly. However, the longer chain soaps are desirable in that they maintain structure and do not dissolve as readily. Unsaturated soaps (e.g., oleic) are soluble and lather quickly, like short-chained soaps, but form a denser, creamier foam, like the longer chained soaps.
[0004] Generally, particularly because of the structuring required to produce and maintain a solid soap bar structuring is provided by longer chain-length soaps) the production of a pure soap bar having enhanced lathering benefit (e.g., quick lather) is considered extremely difficult.
[0005] When synthetic surfactant (e.g., nonionic surfactant) is added to enhance mildness, typically the soap bar must still be predominantly made of long-chain soaps to ensure the bar is well structured and can maintain structure in stamping.
[0006] WO 93/04161 (P&G), for example, discloses bars comprising mixtures of soap, C 14 -C 20 alkyl polyethoxylate nonionic and C 16 -C 18 acyl isethionate (also a mild surfactant). The soap used comprises at least tallow (longer chain, slower lather) and includes cationic polymeric skin mildness aids and, as moisturizers, free fatty acid.
[0007] To overcome poor lathering problems, references in the art have disclosed use of specially tailored soaps (which involved additional. expensive processing) and/or use of additional, expensive co-actives,
[0008] U.S. Pat. No. 5,540,852, Kefauver et al., for example, discloses a mild, lathering personal cleansing soap bar composition comprising from 30 to 85 by wt. tailored fatty acid soap comprising in turn from 50% to 85% of saturated fatty acid soap selected from the group consisting of: myristic, palmitic, and stearic acid soaps. Kefauver fails to disclose that minimum levels of capric and lauric fatty acid soaps and maximum levels of myristic fatty acid are required for enhanced lather.
[0009] U.S. Pat. No. 5,656,579, Chambers et al. discloses a mild toilet soap bar comprising blends of soap with one or more coactives, comprising at least 25% wt. on total actives of Laurie acid soaps. Again, Chambers fails to disclose soap bar formulations having low amounts of myristic acid soap, or having levels of capric and lauric fatty acid soaps as claimed in our invention.
[0010] Thus, previous attempts for enhance mildness and/or in-use performance are provided by specialized tailoring or use of expensive co-actives.
[0011] Nowhere is there disclosed compositions providing enhanced lather while retaining structure using simple, but unexpected, ratios of soap as provided by applicants' claimed invention.
[0012] The present invention is the result of experimentation investigating the use of different fatty acids in varying amounts as an alternative to synthetic surfactants to improve lathering properties while maintaining structuring properties. Surprisingly, soap bars with superior lathering which retained structuring properties can be obtained.
[0013] The compositions of the present invention have shown to yield, bars with substantially improved lather volume performance in respect to total volume.
BRIEF DESCRIPTION OF THE INVENTION
[0014] Quite unexpectedly, applicants have found that using spec ilk blends of fatty acid soaps, wherein minimum amounts of C 8 -C 10 soaps are used; ratios of C 8 -C 10 to C 12 soaps are in defined ranges; and maximum amount of C 14 soap is used; it is possible to make soap bars with enhanced lather while retaining structure relative to other soap blends. The soap bar of the present invention may be extruded or cast-melt.
[0015] Specifically, the invention comprises a soap bar composition comprising:
[0016] a) a fatty acid soap blend in an amount of 30 to 90% by wt. of the soap bar comprising:
(i) caprylic (C 8 ), pelargonic (C 9 ) and capric (C 10 ) acids, their salts or their mixtures thereof in an amount of 0.1 to 40 wt. preferably 10 to 40 wt. % of the fatty acid soap blend; (ii) myristic acid (C 14 ) in amount not higher than 8 wt. % preferably no higher than 4 wt. % of the fatty acid soap blend;
[0019] b) co-adjuvants selected from polyols, polymers, organic and inorganic adjuvants, electrolytes, benefit agents and other minor ingredients in an amount from 0.1 to 50% by weight of the soap composition;
[0020] c) the remainder of water.
[0000] wherein the fatty acid blend comprises a ratio of the sum of caprylic, perlagonic and capric acids to lauric acid, (ΣC 8-10 /C 12 ), of 0.19 to 2.5, more preferably from 0.5 to 2.0 and more preferably from 0.9 to 1.5.
[0021] Specifically, applicants have found that these formulations provide compositions having enhanced hither volume relative to compositions where these criteria are not kept (e.g. C14 is not minimized and ratios of C 8 -C 10 to C 12 are not properly balanced).
DETAILED DESCRIPTION OF THE INVENTION
[0022] The present invention relates to a soap bar composition comprising:
[0023] a) a fatty acid soap blend in an amount of 30 to 90% by wt. of the soap bar comprising:
(i) caprylic, pelargonic and capric acids, their salts or their mixtures thereof in an amount of 0.1 to 40 wt. %. preferably 10 to 40 wt. % of the fatty acid soap blend; (ii) myristic acid in amount not higher than 8 wt. % of the fatty acid soap blend;
[0026] b) co-adjuvants selected from polyols, polymers, organic and inorganic adjuvants, electrolytes, benefit agents and other minor ingredients in an amount from 0.1 to 50% by weight of the soap composition;
[0027] c) the remainder of water.
[0000] wherein the fatty acid blend comprises a ratio of the sum of caprylic, perlagonic and capric acids to lauric acid, (ΣC 8-10 /C 12 ), of 0.19 to 2.5, more preferably from 0.5 to 2.0 and more preferably from 0.9 to 1.5.
Soap Bar Composition
[0028] The present invention relates to extruded or melt cast personal washing bars that comprise specific levels and ratios of various fatty acid soaps; optionally one or more added polyols. polymers, organic and inorganic adjuvant materials, electrolytes, benefit agents and other minor ingredients and the remainder of water. These components of the bar composition that are used to manufacture and evaluate the bars are described below. The bar compositions of the invention are capable of being manufactured by processes that generally involve the extrusion forming of ingots or billets, and stamping or molding of these billets into individual tablets, cakes, or bars and alternatively the products can be obtained by the melt cast process.
Fatty Acid Soap Blend
[0029] The fatty acid soaps, other surfactants and in fact all the components of the bar should be suitable for routine contact with human skin and preferably yield bars that are high lathering,
[0030] The present invention relates to a soap bar composition with unproved lather volume which comprises fatty acid blend soap in an amount of 30 to 90% by wt, of the soap bar. More preferably, the fatty acid blend comprises a fatty acid blend in an amount of 40 to 80% by wt. of the soap bar. Most preferably, the fatty acid blend comprises a fatty acid blend in an amount of 45 to 78% by wt. of the soap bar.
[0031] The fatty acid blend comprises one or more surfactants. The preferred type of surfactant is fatty acid soap. The term “soap” is used herein in its popular sense, i.e., the alkali metal or alkanol ammonium salts of aliphatic, alkanes, or alkene monocarboxylic acids. Sodium, potassium, magnesium, mono-, di- and tri-ethanol ammonium cations, or combinations thereof, are the most suitable for purposes of this invention. In general, sodium soaps are used in the compositions of this invention, but up to about 15% of the soap may be potassium, magnesium or triethanolamine soaps. The soaps useful herein are the well known alkali metal salts of natural or synthetic aliphatic (alkanoic or alkenoic) acids having about 8 to about 24 carbon atoms. They may be described as alkali metal carboxylates of saturated or unsaturated hydrocarbons having about 8 to about 24 carbon atoms.
[0032] The fatty acid blend is made from fatty acids that may be different fatty acids, typically fatty acids containing fatty acid moieties with chain lengths of from C 8 to C 24 . The fatty acid blend may also contain relatively pure amounts of one or more fluty acids. Suitable fatty acids include, but are not limited to, butiric, caproic, caprylic, capric, myristic, myristelaidic, pentadecanoic, palmitic, palmitoleic, margaric, heptadecenoic, stearic oleic, linoleic, linolenic, arachidic, gadoleic, behenic and lignoceric acids and their isomers. in a preferred embodiments, the fatty acid blend has fatty acids with fatty acids moiety chains length of 10 (capric acid) and 12 (Jamie acid) carbon atoms. In preferred embodiments, the fatty acid blend has low levels of fatty acid with saturated fatty acid moiety chain length of 14 carbon atoms (myristic acid).
[0033] The fatty acid blend of the present invention comprises relatively high amounts (e.g. at least 3%, preferably at least 10%) of capric and lauric acids. Moreover, the invention requires from about 25 to about 55% of unsaturated long chain fatty acids (C 18:1 and C 18:2 ). Additionally the fatty acid blend comprises low levels of myristic acid, (e.g. preferably less than 4% by wt.) which, according to the invention, determines the good lathering properties of the resultant soap bar composition.
[0034] In a preferred embodiment, the fatty acid blend may have a proportion of capric acid to lauric acid ranging from 0.5 to 1 to 1.5 to 1.
[0035] The fatty acids may be eventually in the form of free fatty acids, preferably in an amount not higher than 5% of the fatty acid soap blend.
Organic and Inorganic Adjuvant Materials
[0036] The total level of the adjuvant materials used in the bar composition should be in an amount not higher than 50% by wt. of the soap bar composition.
[0037] Suitable starchy materials include natural starch (from corn, wheat, rice, potato, tapioca and the like), pregelatinzed starch, various physically and chemically modified starch and mixtures thereof By the term natural starch is meant starch which has not been subjected to chemical or physical modification—also known as raw or native starch.
[0038] A preferred starch is natural or native starch from maize (corn), cassava, wheat, potato, rice and other natural sources of it. Raw starch with different ratio of amylose and amylopectin: e.g. maize (25% amylose); waxy maize (0%); high amylose maize (70%); potato (23%); rice (16%); sago (27%); cassava (18%); wheat (30%) and others. The raw starch can be used directly or modified during the process of making the bar composition such that the starch becomes gelatinized, either partially or fully gelatinized.
[0039] Another suitable starch is pre-gelatinized which is starch that has been gelatinized before it is added as an ingredient in the present bar compositions. Various forms are available that will gel at different temperatures, e.g., cold water dispersible starch. One suitable commercial pre-gelatinized starch is supplied by National Starch Co. (Brazil) under the trade name FARMAL CS 3400 but other commercially available materials having similar characteristics are suitable.
Polyol
[0040] Another organic adjuvant could be a polyol or mixture of polyols. Polyol is a term used herein to designate a compound having multiple hydroxyl groups (at least two, preferably at least three) which is highly water soluble, preferably freely soluble, in water.
[0041] Many types of polyols are available including: relatively low molecular weight short chain polyhydroxy compounds such as glycerol and propylene glycol; sugars such as sorbitol, manitol, sucrose and glucose: modified carbohydrates such as hydrolyzed starch, dextrin and maltodextrin, and polymeric synthetic polyols such as polyalkylene glycols, for example polyoxyethylene glycol (PEG) and polyoxypropylene glycol (PPG).
[0042] Especially preferred polyol are glycerol, sorbitol and their mixtures.
[0043] The level of polyol is critical in forming a thermoplastic mass whose material properties are suitable for both high speed manufacture (300-400 bars per minute) and for use as a personal washing bar, lit has been found that when the polyol level is too low, the mass is not sufficiently plastic at the extrusion temperature (e.g., 40o C to 45o C) and the bars tend to exhibit higher mushing and rates of wear. Conversely, when the polyol level is too high, the mass becomes too soft to be formed into bars by high speed at normal process temperature.
[0044] The adjuvant system may optionally include insoluble particles comprising one or a combination of materials. By insoluble particles is meant materials that are present in solid particulate form and suitable for personal washing.
[0045] The insoluble particles should not be perceived as scratchy or granular and thus should have a particle size less than 30( )microns, more preferably less than 100 microns and most preferably less than 50 microns.
[0046] Preferred inorganic particulate material includes talc and calcium carbonate. Talc is a magnesium silicate mineral material, with a sheet silicate structure and a composition of Mg3Si4 (OH)22, and may be available in the hydrated form. It has a plate-like morphology, and is essentially oleophilic/hydrophobic, i.e., it is wetted by oil rather than water.
[0047] Calcium carbonate or chalk exists in three crystal forms: calcite, aragonite and vaterite. The natural morphology of calcite is rhombohedral or cuboidal, acicular or dendritic for aragonite and spheroidal for vaterite.
[0048] Commercially, calcium carbonate or chalk known as precipitated calcium carbonate is produced by a carbonation method in which carbon dioxide gas is bubbled through an aqueous suspension of calcium hydroxide. In this process the crystal type of calcium carbonate is calcite or a mixture of calcite and aragonite.
[0049] Examples of other optional insoluble inorganic particulate materials include alumni( )silicates, aluminates, silicates, phosphates, insoluble sulfates, borates and clays (e.g., kaolin, china clay) and their combinations.
[0050] Organic particulate materials include: insoluble polysaccharides such as highly crosslinked or insolubilized starch (e.g., by reaction with a hydrophobe such as octyl succinate) and cellulose; synthetic polymers such as various polymer lattices and suspension polymers; insoluble soaps and mixtures thereof.
[0051] The structuring system can comprise up to 10% insoluble particles, preferably 5% to 8%, based on the total weight of the bar composition.
Optional Ingredients
Synthetic Surfactants:
[0052] The bar compositions can optionally include non-soap synthetic type surfactants (detergents)—so called syndets. Syndets can include anionic surfactants, nonionic surfactants, amphoteric or zwitterionic surfactants and cationic surfactants.
[0053] The level of synthetic surfactant present in the bar is generally less than 25%, preferably less than 15%, preferably up to 10%, and most preferably from 0 to 7% based on the total weight of the bar composition.
[0054] The anionic surfactant may be, for example, an aliphatic sulfonate, such as a primary alkane (e.g., C 8 -C 22 ) sulfonate, primary alkane (e.g. C 8 -C 22 ) disulfonate, C 8 -C 22 alkene sulfonate, C 8 -C 22 hydroxyalkane sulfonate or alkyl glyceryl ether sulfonate (AGS); or an aromatic sulfonate such as alkyl benzene sulfonate. Alpha olefin sulfonates are another suitable anionic surfactant.
[0055] The anionic may also be an alkyl sulfate (e.g., C 12 -C 18 alkyl sulfate), especially a primary alcohol sulfate or an alkyl ether s Irate (including alkyl glyceryl ether sulfates).
[0056] The anionic surfactant can also be a sulfonated fatty acid such as alpha sulfonated tallow fatty acid, a sulfonated fatty acid ester such as alpha sulfonated methyl tallowate or mixtures thereof.
[0057] The anionic surfactant may also be alkyl sulfosuccinates (including mono- and dialkyl e.g., C 6 -C 22 sulfosuccinates): alkyl and acyl taurates, alkyl and acyl sarcosinates, sulfoacetates, C 8 -C 22 alkyl phosphates and phosphates, alkyl phosphate esters and alkoxyl alkyl phosphate esters, acyl lactates or lactylates, C 8 -C 22 monoalkyl succinates and maleates, sulphoacetates, and acyl isethionates.
[0058] Another class of anionics is C 8 to C 20 alkyl ethoxy (1-20 EO) carboxylates.
[0059] Another suitable anionic surfactant is C 8 -C 18 acyl isethionates. These esters are prepared by reaction between alkali metal isethionate with mixed aliphatic fatty acids having from 6 to 18 carbon atoms and an iodine value of less than 20. At least 75% of the mixed fatty acids have from 12 to 18 carbon atoms and up to 25% have from 6 to 10 carbon atoms. The acyl isethionate may also be alkoxylated isethionates
[0060] Acyl isethionates, when present, will generally range from about 0.5% to about 25% by weight of the total composition.
[0061] In general, the anionic component will comprise the majority of the synthetic surfactants used in the bar composition.
[0062] Amphoteric detergents which may be used in this invention include at least one acid group. This may be a carboxylic or a sulphonic acid group. They include quaternary nitrogen and therefore are quaternary amido acids. They should generally include an alkyl or alkenyl group of 7 to 18 carbon atoms. Suitable amphoteric surfactants include amphoacetates, alkyl and alkyl amido betaines, and alkyl and alkyl amido sulphobetaines.
[0063] Amphoacetates and diamphoacetates are also intended to be covered in possible zwitterionic and/or amphoteric compounds which may be used.
[0064] Suitable nonionic surfactants include the reaction products of compounds having a hydrophobic group and a reactive hydrogen atom, for example aliphatic alcohols or fatty acids, with alkylene oxides, especially ethylene oxide either alone or with propylene oxide. Examples include the condensation products of aliphatic (C 8 -C 18 ) primary or secondary linear or branched alcohols with ethylene oxide, and products made by condensation of ethylene oxide with the reaction products of propylene oxide and ethylenediamine. Other so-called nonionic detergent compounds include long chain tertiary amine oxides, long chain tertiary phosphine oxides and dialkyl sulphoxides.
[0065] The nonionic may also be a sugar amide, such as alkyl polysaccharides and alkyl polysaccharide amides.
[0066] Examples of cationic detergents are the quaternary ammonium compounds such as a alkyldimethylammonium halides.
[0067] Other surfactants which may he used are described in U.S. Pat. No. 3,723,325 to Parran Jr. and “Surface Active Agents and Detergents” (Vol. I & II) by Schwartz, Perry & Berth, both of which is also incorporated into the subject application by reference.
Finishing Adjuvant Materials:
[0068] These are ingredients that improve the aesthetic qualities of the bar especially the visual, tactile and olefactory properties either directly (perfume) or indirectly (preservatives). A wide variety of optional ingredients can be incorporated in the bar composition of the invention. Examples of adjuvants include but are not limited to: perfumes; opacifying agents such as fatty alcohols, ethoxylated fatty acids, solid esters, and TiO 2 ; dyes and pigments; pearlizing agent such as TiO 2 coated micas and other interference pigments; plate like mirror particles such as organic glitters; sensates such as menthol and ginger; preservatives such as dimethyloldimethylhydantoin (Glydant XL1000), parabens, sorbic acid and the like; anti-oxidants such as, for example, butylated hydroxytoluene (BHT); chelating agents such as salts of ethylene diamine tetra acetic acid (EDTA) and trisodium etridronate; emulsion stabilizers; auxiliary thickeners; buffering agents; and mixtures thereof.
[0069] The level of pearlizing agent should be between about 0.1% to about 3%, preferably between 0.1% and 0.5% and most preferably between about 0.2 to about 0.4% based on the total weight of the bar composition.
Skin Benefit Agents:
[0070] A particular class of optional ingredients highlighted here is skin benefit agents included to promote skin and hair health and condition. Potential benefit agents include but are not limited to: lipids such as cholesterol, ceramides, and pseudoceramides; antimicrobial agents such as TRICLOSAN; sunscreens such as cinnamates; other types of exfoliant particles such as polyethylene beads, walnut shells, apricot seeds, flower petals and seeds, and inorganics such as silica, and pumice; additional emollients (skin softening agents) such as long chain alcohols and waxes like lanolin; additional moisturizers; skin-toning agents; skin nutrients such as vitamins like Vitamin C, D and E and essential oils like bergamot, citrus unshiu, calamus, and the like; water soluble or insoluble extracts of avocado, grape, grape seed, myrrh, cucumber, watercress, calendula, elder flower, geranium, linden blossom, amaranth, seaweed, gingko, ginseng, carrot; impatiens balsamina, camu camu, alpina leaf and other plant extracts such as witch-hazel, and mixtures thereof.
[0071] The composition can also include a variety of other active ingredients that provide additional skin (including scalp) benefits, Examples include anti-acne agents such as salicylic and resorcinol; sulfur-containing D and L amino acids and their derivatives and salts, particularly their N-acetyl derivatives; anti-wrinkle, anti-skin atrophy and skin-repair actives such as vitamins (e.g., A, E and K), vitamin alkyl esters, minerals, magnesium, calcium, copper, zinc and other metallic components; retinoic acid and esters and derivatives such as retinal and retinol, vitamin B3 compounds, alpha hydroxy acids, beta hydroxy acids, e.g. salicylic acid and derivatives thereof, skin soothing agents such as aloe vera, jojoba oil, propionic and acetic acid derivatives, fenamic acid derivatives; artificial tanning, agents such as dihydroxyacetone; tyrosine; tyrosine esters such as ethyl tyrosinate and glucose tyrosinate; skin lightening agents such as aloe extract and niacinamide, alpha-glyceryl-L-ascorbic acid, aminotyroxine, ammonium lactate, glycolic acid, hydroquinone, 4 hydroxyanisole, sebum stimulation agents such as bryonolic acid, dehydroepiandrosterone (DHEA) and orizano; sebum inhibitors such as aluminum hydroxy chloride, corticosteroids, dehydroacetic acid and its salts, dichlorophenyl imidazoldioxolan (available from Elubiol); anti-oxidant effects, protease inhibition; skin tightening agents such as terpolymers of vinylpyrrolidone, (meth)acrylic acid and a hydrophobic monomer comprised of long chain alkyl (meth)acrylates; anti-itch agents such as hydrocortisone, methdilizine and trimeprazine hair growth inhibition; 5-alpha reductase inhibitors; agents that enhance desquamation; anti-glycation agents; anti-dandruf agents such as zinc pyridinethione; hair growth promoters such as finasteride, minoxidil, vitamin D analogues and retinoic acid and mixtures thereof.
Electrolyte
[0072] The soap bars include 0.5 wt % to 5 wt % electrolyte. Preferred electrolytes include chlorides, sulphates and phosphates of alkali metals or alkaline earth metals. Without wishing, to be bound by theory it is believed that electrolytes help to structure the solidified soap mass and also increase the viscosity of the molten mass by common ion effect. Comparative soap bars without any electrolyte were found to be softer. Sodium chloride and sodium Sulphate are the most preferred electrolyte, more preferably at 0.6 to 3.6 and most preferably at 1.0 to 3.6 wt %.
Polymers
[0073] The soap bars may include 0.1 to 5 wt % of a polymer selected from acrylates or cellulose ethers. Preferred acrylates include cross-linked acrylates, polyacrylic acids or sodium polyacrylates. Preferred cellulose ethers include carboxymethyl celluloses or hydroxyalkyl celluloses. A combination of these polymers may also be used, provided the total amount of polymers does not exceed 5 wt%.
Acrylates
[0074] Preferred bars include 0.1 to 5% acrylates. More preferred bars include 0.15 to 3% acrylates. Examples of acrylate polymers include polymers and copolymers of acrylic. acid crosslinked with polyallylsucrose as described in U.S. Pat. No. 2,798,053 which is herein incorporated by reference. Other examples include polyacrylates, acrylate copolymers or alkali swellable emulsion acrylate copolymers (e.g, ACULYN® 33 Ex. Rohm and Haas; CARBOPOL® Aqua SF-1 Ex, Lubrizol Inc.), hydrophobically modified alkali swellable copolymers (e.g., ACULYN® 22, ACULYN® 28 and ACULYN® 38 ex. Rohm and Haas). Commercially available crosslinked homopolymers of acrylic acid include CARBOPOL® 934, 940, 941, 956, 980 and 996 carbomers available from Lubrizol Inc. Other commercially available crosslinked acrylic acid copolymers include the CARBOPOL® Ultrez grade series 10, 20 and 21) and the ETD series (ETD 2020 and 2050) available from Lubrizol Inc.
[0075] CARBOPOL® Aqua SF-1 is a particularly preferred acrylate. This compound is a slightly cross-linked, alkali-swellable acrylate copolymer which has three structural units; one or more carboxylic acid monomers having 3 to 10 carbon atoms, one or more vinyl monomers and, one or more mono- or polyunsaturated monomers.
Cellulose Ethers
[0076] Preferred bars include 0.1 to 5% cellulose ethers. More preferred bars include 0.1 to 3% cellulose ethers. Preferred cellulose ethers are selected from alkyl celluloses, hydroxyalkyl celluloses and carboxyalkyl celluloses. More preferred bars include hydroxyalkyl celluloses or carboxyalkyl celluloses and particularly preferred bars include carboxyalkyl cellulose.
[0077] Preferred hydroxyalkyl cellulose includes hydroxymethyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose and ethyl hydroxyethyl cellulose.
[0078] Preferred carboxyalkyl cellulose includes carboxymethyl cellulose. It is particularly preferred that the carboxymethyl cellulose is in form of sodium salt of carboxymethyl cellulose.
Wax and Polyalkyleneglycols
[0079] Preferred wax includes paraffin wax and microcrystalline wax. When polyalkyleneglycols are used, preferred bars may include 0.01 to 5 wt % Polyalkyleneglycols, more preferably 0.03 to 3 wt % and most preferably 0.5 to 1 wt %. Suitable examples include polyethyleneglycol and polypropyleneglycol. A preferred commercial product is POLYOX® sold by The Dow Chemical Company.
Protocol and Examples
Lather Volume Test
1. Introduction
[0080] The amount of lather generated by a soap bar is an important parameter affecting consumer preference. The lather volume test described herein gives a measure of lather generation under standard conditions, thus allowing objective comparison of different soap formulations.
2. Principle
[0081] Lather is generated by trained technicians using a standardised method. The lather is collected and its volume measured.
3. Equipment
[0082]
[0000]
Washing up bowl
1 per operator capacity 10 litres
Soap drainer dishes
1 per sample
Surgeons' rubber gloves
Tall cylindrical glass beaker
400 mL, 25 mL graduated (Pyrex n o 1000)
Thermometer
Glass rod
Procedure
[0083] i. Tablet Pre-Treatment
[0084] Wearing the surgeon's glove previously washed in plain soap, wash down all test tablets at least 10 minutes before starting the test sequence. This is best done by twisting them about 20 times through 180 under running water.
[0000] ii. Place about 5 litres of water of known hardness and at a. specified temperature in a bowl, Change the water after each bar of soap has been tested.
iii. Take up the tablet, dip it in the water and remove it. Twist the tablet IS times, between the hands, through 180. Place the tablet on the soap dish.
iv. The lather is generated by the soap remaining on the gloves.
[0085] 1: Stage Rub one hand over the other hand (two hands on same direction) 10 times in the same way.
[0086] Stage 2: Grip the right hand with the left, or vice versa, and force the lather to the tips of the fingers.
[0087] This operation is repeated five times.
[0088] Repeat Stages 1 and 2.
[0089] Place the lather in the beaker.
[0000] v. Repeat the whole procedure of lather generation from paragraph iii, twice more, combining all the lather in the beaker.
vi. Stir the combined lather gently to release large pockets of air. Read and record the volume.
[0090] Data analysis is carried out by two way analysis of variance, followed by Turkey's Test.
EXAMPLES
[0091] Solid moisturizing personal wash bars were prepared with different percentages of fatty acids in accordance with the formulations herein below.
[0092] The fatty acids used to prepare the formulations are supplied by Cosmoquimica under the commercial Name of Edenor® CS 98/100 (Caprilic acid); Edenor® C10 981100 (Capric acid); Edenor® C12 98/100 (Lauric acid); Edenor® C14 98/100 (Myristic acid); Edenor® C16 98/100 (Palmitic acid); Edenor® C18 98/100 (Stearic acid); Edenor® C1.8:1 98/1.00 (Oleic acid).
[0093] Other tatty acids possible suppliers are Quimico Anastâcio, Emery Oleochemicals and Aboissa Oleos Vegetais.
[0000]
TABLE 1
Comparative examples
Composition
A
B
C
D
TFM
77.88
77.88
77.88
77.88
Sodium Caprylate (C8)
1.44
0.75
0.41
1.1
Sodium Caprate (C10)
1.45
0.77
0.43
1.11
Sodium Laurate (C12)
19.89
10.5
5.8
15.2
ratio (ΣC 8-10 /C 12 )
0.15
0.14
0.14
0.14
Sodium Myristate (C14)
7.21
4.34
2.92
5.77
Short saturated:long unsaturated
35.36
36.47
36.34
36.69
(C18:1 + C18:2)
Glycerol
0.5
0.5
0.5
0.5
Capric Acid (C10)
—
—
—
—
Lauric Acid (C12)
—
—
—
—
Other Ingredients (%)
up to
up to
up to
up to 100%
100%
100%
100%
Lather volume (mL) ± 10 ml
250
220
200
240
Composition
E
F
TFM
77.88
76.96
Sodium Caprylate (C8)
—
0.92
Sodium Caprate (C10)
1
0.7
Sodium Laurate (C12)
9.5
10.12
ratio (ΣC 8-10 /C 12 )
0.10
0.16
Sodium Myristate (C14)
21.5
4.15
Short saturated:long unsaturated
50
36.74
(C18:1 + C18:2)
Glycerol
0.5
0.5
Capric Acid (C10)
—
1
Lauric Acid (C12)
—
—
Other Ingredients (%)
up to 100%
up to 100%
Lather volume (mL) ± 10 ml
240
260
[0000]
TABLE 2
Invention examples
exam-
exam-
exam-
exam-
Composition
ple 1
ple 2
ple 3
ple 4
TFM
77.88
77.88
77.88
72.20
Sodium Caprylate (C8)
1.55
1.05
2.04
2.04
Sodium Caprate (C10)
10.56
7.07
14.05
14.05
Sodium Laurate (C12)
10.4
7.3
13.49
13.49
ratio (ΣC 8-10 /C 12 )
1.16
1.11
1.19
1.19
Sodium Myristate (C14)
1.87
1.74
2.01
2.01
Short saturated:long unsaturated
36.99
36.67
35.76
35.76
(C18:1 + C18:2)
Glycerol
0.5
0.5
0.5
6.66
Capric Acid (C10)
—
—
—
—
Lauric Acid (C12)
—
—
—
—
Other Ingredients (%)
up to
up to
up to
up to
100%
100%
100%
100%
Lather volume (mL) ± 10 ml
310
280
370
370
exam-
exam-
exam-
exam-
Composition
ple 5
ple 6
ple 7
ple 8
TFM
77.88
77.88
77.88
77.88
Sodium Caprylate (C8)
0.56
19
0.3
0.0
Sodium Caprate (C10)
3.58
1
20
12.0
Sodium Laurate (C12)
4.2
8
20
12.0
ratio (ΣC 8-10 /C 12 )
0.99
2.50
1.01
1.00
Sodium Myristate (C14)
1.62
4
0.4
8.0
Short saturated:long unsaturated
39.1
50
15
50
(C18:1 + C18:2)
Glycerol
0.5
0.5
0.5
0.5
Capric Acid (C10)
—
—
—
—
Lauric Acid (C12)
—
—
—
—
Other Ingredients (%)
up to
up to
up to
up to
100%
100%
100%
100%
Lather volume (mL) ± 10 ml
230
350
380
340
[0000]
TABLE 3
Examples of compositions with fatty acid blends that include free
fatty acids of capric and lauric acids.
Composition
example 9
example 10
example 11
TFM
76.96
76.04
75.12
Sodium Caprylate (C8)
0.92
0.92
0.92
Sodium Caprate (C10)
0.7
0.7
0.7
Sodium Laurate (C12)
10.12
10.12
10.12
Sodium Myristate (C14)
4.15
4.15
4.15
Short saturated:long
36.74
36.74
36.74
unsaturated (C18:1 + C18:2)
Glycerol
0.5
0.5
0.5
Capric Acid (C10)
—
1
3
Lauric Acid (C12)
1
1
—
Other Ingredients (%)
up to 100%
up to 100%
up to 100%
Lather volume (mL) ± 10 ml
250
270
270
[0094] Comparative examples A to F show typical soap bar compositions currently produced by different manufacturers for which the performance is not as effective as the performance of the formulations described herein. It can be seen that products relatively high amounts of soap blends of myristic acid (C 14 ) have relatively lower lather volumes when other short-chain soaps are not balanced in accordance with the invention (e.g., ratio of C 8 -C 10 /C 12 at least 0.19. From comparative examples A-F, the impact of myristic acid (C14). or its salt, sodium myristate on the lathering of the soap bar can be seen, if the other short chain fatty acids soaps are not balanced accordingly, as will he shown in table 2. In general, high amounts of such fatty acid decrease the lathering performance reducing the amount of lather produced. Higher levels of myristic acid can only be applied, for example, when the ratios of C8-C10 soaps to lauric (C12) are balanced accordingly, as shown in example 14. Comparative examples D and F show the influence of myristic acid (C14). A slight decrease of myristic acid (C14), from 5,77 in Example D, to 4.15 in Example F is enough to increase lather from 240 to 260 milliliters. The maximum amount of soaps of myristic acid that yield bars with good performance has been determined to be 8.0%.
[0095] Without being bound by theory, it is believed that the myristic (C14) acid, or its salt, sodium mryistate, have a carbon chain that is not short enough for producing lather and is not long enough for crystallizing together with the other long saturated soaps of fatty acids, thus disturbing the surfactant system in a fashion that depletes its lathering. On the other hand, short chain fatty acids—from caprylic (C8) to lauric (C12) acids have a smaller carbon chain that does not disturb the lathering effect and thus perform well to create bubbles and lather in high amounts.
[0096] Additionally, high amounts of caprylic (C8) and capric (C10) acids renders good to optimum lathering properties, specially lather volume, Comparative Example F has comparable amount of myristic acid (C14), 4.34%, to Example 12, 4%. In Example 12, the amount: of caprylic acid (C8) is 19%, which is nearly 20 times higher than the amount in Comparative. This translates to amounts of lather substantially higher, i.e. 240 ml in Example 4 and 350 ml in Example 12.
[0097] Capric acid (C10) also plays an important role in generating high amounts of volume of lather, Comparative A has low amounts at Capric acid (C10), only 1.45%. Example 1 shows a substantial amount of Capric acid (C10), 10.56% and higher lather volume, i.e. from 250 ml from Example 1 to 310 ml of lather in Example 1.
[0098] It has been found that when the fatty acid blend comprises a ratio of the sum of caprylic, perlagonic and capric acids (ΣC 8-10 ) to lauric acid (C 12 ) of between 0.19 to 2.5, the lather volume increases by ca. 40-50% when compared to conventional soaps. When one compares the examples in Table 1 with those in Table 2 it can see that the ratio of the sum of caprylic, perlagonic and capric acids to lauric acid (ΣC 8-10 /C 12 ) in these examples varies substantially. In the comparative examples in Table 1 the ratio ranges from 0.10 to 0.16, presenting, an average lather volume of 235 ml; whereas in the invention examples 3 to 8, the ratio ranges from 0.99 to 2.5, yielding products with average lather volumes as high as 330 mL. In this sense the ratio (ΣC 8-10 /C 12 ) is a significant predictor of high amounts of lather for soap bar compositions. | The present invention relates to soap bars having improved lather. Specifically, by limiting amounts of myristic acid and keeping specifically defined ratios of sum of C 8 -C 10 fatty acids to C 12 fatty acid bars having substantially improved lather and unexpectedly obtained. | 0 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] This invention relates generally to a method and device using a targeted light source and a photosensitizer to streamline the process of repairing internal body passageways, prevent restenosis, and minimize re-injury after angioplasty treatment.
[0003] 2. Invention Disclosure Statement
[0004] The most common problem with any angioplasty procedure is restenosis, a re-closing of the affected passageway opened by the procedure. This effect is believed to be due to cell proliferation, triggered by the exerted pressure and the lesion caused by the balloon angioplasty. Restenosis occurs in about 30% of patients. The use of stents, or tiny expanding metal scaffolds, is the most common method used to prevent restenosis. However, restenosis through the stent or around the stented area is quite common.
[0005] Constrictions in the coronary artery are caused by a buildup of plaque. Plaque can occur in many forms, from a thick viscous consistency (similar to toothpaste) to a rock-hard consistency depending on the proportion of components, which may include calcium, fibrous tissue, fatty deposits, organized clots and thrombus.
[0006] Atherosclerosis is a common problem among humans. Fatty substances (lipids), or plaques, form deposits in and beneath the intima—the innermost membrane lining arteries and veins. Atherosclerosis commonly affects large and medium sized arteries. Most commonly affected are the aorta, and the iliac, femoral, coronary, and cerebral arteries. Health problems result from atherosclerosis when reduced blood flow due to constriction of one of the passageways restricts blood flow to a particular tissue or organ. Restricted blood flow compromises and restricts organ or tissue function.
[0007] Approximately four million people in the United States suffer from artherosclerotic coronary artery disease. Many of these people are likely to suffer or die from myocardial infarction, commonly known as heart attack. Heart disease is, in fact, the leading cause of death in the United States. Thrombosis in the coronary artery beyond the artherosclerotic constriction is the usual cause of heart attacks. A procedure that can open artherosclerotic constrictions thereby permitting the normal flow of blood to the heart can reduce many deaths and disabilities caused by heart disease.
[0008] Modern treatment of atherosclerotic blood passageways usually involves one of two treatments: bypass and/or angioplasty. In bypass treatment, a portion of a blood passageway is borrowed from another area in the body and grafted around the affected passageway. This treatment involves invasive surgery, especially when dealing with the aorta, coronary artery, or other vessels involving the heart. Furthermore, bypass surgery does not heal the affected site, and occurrences of atherosclerosis in the grafted passage are relatively common.
[0009] Another method of treating atherosclerosis is angioplasty. In angioplasty, a catheter of some sort is introduced into the passageway. In most methods, the angioplasty catheter, usually equipped with a guidewire, moves along the body passageway to the sclerotized area. A balloon contained inside of the catheter inflates, displacing the plaque and re-opening the passageway.
[0010] In another use of the prior art, a photosensitizer is introduced at the sclerotized area prior to introduction of the catheter. After time for the photosensitizer to target and saturate the sclerotized area, a catheter is introduced into the body passageway. Fibers are then inserted into the catheter. The fibers conduct light from some kind of source, i.e. a laser. The laser or other light source activates the photosensitizer in the sclerotized area in order to destroy the plaque. A balloon may or may not be used in this approach to further treat the sclerotized area of the blood passageway. This form of angioplasty is called Photodynamic Therapy (PDT), or intracoronary brachytherapy.
[0011] The photoactivating device employed for intracoronary brachytherapy usually comprises a monochromatic light source such as a laser, the light output of which may be coupled to an invasive light delivery catheter for conduction and delivery to a remote target tissue. Such interventional light delivery catheters are well known in the art and are described, for example, in U.S. Pat. No. 4,512,762 (Spears). In that invention a balloon is illuminated to activate the photosensitizer.
[0012] Generally, the prior art of intracoronary brachytherapy involves at least five steps: insertion of a guidewire; insertion of a catheter over the guidewire; removal of the guidewire; insertion of a fiberoptic wire; and finally, irradiation. The present invention is a method to prevent restenosis by using a novel catheter with light conducting means and a targeting mechanism for focusing that light source on a photosensitizer to treat a sclerotized area of a human body passageway. Most balloon angioplasty procedures do not involve radiation to prevent cell growth in the intima. Instead, they aim to compress or displace cells in a sclerotized vessel with a stent or other means. These treatments tend to encourage restenosis by stimulating a responsive force in the vessel wall, or stimulating the proliferation of cells in the area to re-take its original shape.
[0013] The present invention provides a non-mechanical method and product for preventing restenosis by irradiation. A “fiberoptic guidewire” assists the doctor or technician in navigating body passageways, and also conducts radiation to its own diffuser to engage in PDT. Alternatively, a balloon catheter is manufactured to conduct radiation to an obstructed body passageway. Either embodiment streamlines the angioplasty procedure.
OBJECTIVES AND BRIEF SUMMARY OF THE INVENTION
[0014] It is an object of the present invention to provide a method to prevent or minimize occurrences of restenosis after angioplasty.
[0015] It is also an object of the present invention to streamline the process of angioplasty to reduce patient exposure and increase the safety of the process.
[0016] It is another object of the present invention to provide a guidewire capable of transmitting radiation, hereinafter referred to as a “fiberoptic guidewire,” to streamline the angioplasty process and prevent restenosis.
[0017] It is a further object of the present invention to provide a fiberoptic guidewire with a diffuser end capable of transmitting radiation to a sclerotized body passageway.
[0018] It is still another object of the present invention to provide a catheter manufactured to conduct radiation, either by insertion of optical fibers in the tubular structure or by manufacturing the catheter of a homogeneous light-conducting polymer.
[0019] Briefly stated, the present invention provides a novel device and method for preventing restenosis and streamlining the angioplasty procedure. The device and method provide a fiberoptic guidewire, or, alternatively, a light-conducting catheter, to decrease the size of the angioplasty device, decrease the overall time of the process, and increase the safety of the procedure. The present invention delivers radiation to a sclerotized area after balloon angioplasty treatment to prevent restenosis. Radiation delivered via the catheter or fiberoptic guidewire discourages the cell proliferation and cell growth after angioplasty, thereby improving the chances of avoiding restenosis.
[0020] The above, and other objects, features and advantages of the present invention will become apparent from the following description read in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF FIGURES
[0021] [0021]FIG. 1 shows a fiberoptic guidewire with a diffuser in a sclerotized body passageway.
[0022] [0022]FIG. 2 is a continuation of FIG. 1, showing a balloon catheter circumscribing the fiberoptic guidewire in the sclerotized body passageway.
[0023] [0023]FIG. 3 shows a balloon catheter equipped with optical fibers in its tubular structure circumscribing a conventional guidewire.
[0024] [0024]FIG. 4 is a cross section of the catheter described in FIG. 3 down its longitudinal axis.
[0025] [0025]FIG. 5 is another embodiment of the catheter in FIG. 3 manufactured of a light-conducting polymer.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0026] The entire angioplasty process is streamlined considerably by the present invention. In the present state of the art, there are several steps to the angioplasty procedure: Introduction of a standard guidewire; introduction of a catheter over a guidewire; removal of the guidewire; introduction of an optical fiber; inflation of the balloon, irradiation, and removal of the entire system. In the present invention, light radiation is transmitted through the fiberoptic guidewire, or alternatively the catheter. The length and complication of the angioplasty process is greatly decreased. A fiberoptic guidewire eliminates the need for of different means for navigation and irradiation. The prior art provides for separate fibers or possibly separate lumens in the catheter for movement over the guidewire and transmission of radiation. The present invention streamlines the process by combining the functions of the guidewire and radiation transmitter, or by transmitting radiation via the catheter itself. The manufacture of a catheter with light-conducting properties also alleviates the need for removal of the guidewire and insertion of a means of irradiation. Decreasing the amount of time that a vessel is subject to a foreign body increases the safety of the process. In addition, the size of the device decreases with the decreased need for lumens for a guidewire, gas, and fiberoptic transmission.
[0027] In one preferred embodiment, a fiberoptic guidewire is manufactured in accordance with FIG. 1. This fiberoptic guidewire alleviates the need for a separate fiber or wire for irradiation.
[0028] A photosensitizer is introduced at a sufficient time prior to beginning the minimally invasive procedure to allow for, preferably, location and targeting of the sclerosis and/or plaque. The fiberoptic guidewire is then introduced into the body passageway. The fiberoptic guidewire has a diffuser located near the distal end. The diffuser will allow for homogeneous and/or differential distribution of radiation at a selected power and intensity to discourage growth and proliferation of the cells in either the vessel walls or the plaque. Various methods of creating homogeneous diffusion are known in the prior art. U.S. Pat. No. 5,196,005 (Doiron & Narcise) describes a method for placing diffusion tips on optical fibers. U.S. Pat. No. 5,231,684 (same inventors) describes the use of a microlens attached to the end of an optical fiber for diffusion of radiation. The present invention envisions a diffuser with a section of guidewire extending distally for optimal navigation in a body passageway. A variation of the prior art that allows an extension of guidewire distally from the distal end of the diffuser is used in the present invention.
[0029] Extending distally from the diffuser, a short piece of guidewire allows for conventional navigational advantages of a guidewire for location of the affected area of the body passageway. The proximal end of the fiberoptic guidewire extends from the diffuser through the body passageway to the portion exiting from the patient and connected to the light source. Methods and devices to allow handling and movement of the guidewire by a doctor or technician are known in the prior art.
[0030] By using the described fiberoptic guidewire, the means to transmit radiation are in place. A balloon catheter is then introduced that circumscribes the guidewire, as shown in FIG. 2. After proper positioning of the catheter, the balloon is inflated to displace the plaque. The light source connected to the proximal end of the guidewire is then activated, irradiating the plaque and vessel walls. Irradiating the plaque and activating the photosensitizer located within the plaque discourages cell proliferation and growth—two responses by the cell wall and/or plaque buildup to an exerted force (the angioplasty balloon) that cause restenosis in 30% of patients that receive angioplasty treatment.
[0031] In another preferred embodiment, the light conducting means are located within the catheter. In this device, a photosensitizer is again introduced. A standard, non-fiberoptic guidewire is introduced to assist the doctor or technician in navigating the body passageway to the sclerosis or constriction. The balloon catheter, again circumscribing the guidewire, is introduced and navigated along the guidewire to the affected area.
[0032] The catheter is manufactured to conduct radiation to the affected area. In one variation of the present embodiment, the tubular structure of the balloon catheter is manufactured in accordance with FIG. 4. Optical fibers embedded in the tubular structure are enclosed in lumens that allow space for differential bending and extension/contraction of the fibers as opposed to the catheter body itself. Fibers of quartz, glass, and plastic are known in the field of fiberoptics and are suitable for use in this embodiment. At least one other lumen exists for free movement of the guidewire relative to the catheter.
[0033] The larger lumens for optical fibers can also be used for transmission of a gas or liquid for inflation of the balloon. The use of gases or liquids for inflation of a balloon catheter is well known in the art. U.S. Pat. No. 4,512,762 (Spears) describes the use of a lumen to transmit pressurized gas to a balloon catheter for inflation. The optical fibers extend distally to the balloon itself, where they transmit radiation to the balloon. Upon inflation of the balloon and displacement of the plaque, the light source is activated, transmitting radiation along the optical fibers and to the inflated balloon. The means of transmission is designed for homogeneous or, if desired, differential transmission of radiation throughout the balloon to the sclerotized area for maximum irradiation.
[0034] The irradiation of the plaque and vessel walls activates the photosensitizer and prevents restenosis by discouraging cell growth and cell proliferation in the vessel walls and the plaque. These processes of growth and proliferation are generally attributed as causes of restenosis.
[0035] In another variation of this preferred embodiment, the catheter body itself is manufactured using a homogeneous light-conducting polymer in accordance with FIG. 5. This polymer will conduct radiation from a light source on its proximal end to the affected area through the angioplasty balloon. At the distal end of the catheter, a diffuser section of the catheter transmits radiation from the catheter walls to the balloon or directly to the plaque and vessel wall. There are several diffusers that are well known in the field of PDT that can be used, or variations of those diffusers can be manufactured to ideally suit the present application.
[0036] The catheter contains at least one lumen for circumscribing the guidewire and transmission of a liquid or gas for inflation of the catheter balloon. In this variation, the angioplasty procedure would be similar to the previous variation. The photosensitizer is introduced; a guidewire is inserted. The catheter is inserted over the guidewire, and the balloon is inflated, displacing the obstruction in the body passageway. The area is then irradiated, preventing restenosis.
[0037] Once again, the angioplasty procedure is streamlined by introduction of a catheter with light-conducting properties designed specifically for transmission of radiation to an obstruction in a human blood vessel or other body passageway eliminates the need for a separate fiber introduced solely for the purpose of transmitting radiation. The time saved in the procedure translates into increased safety for the patient undergoing angioplasty treatment.
[0038] The present invention is further illustrated by the following examples, but is not limited thereby.
EXAMPLE 1
[0039] [0039]FIG. 1 shows body passageway 100 affected with obstruction 102 . The distal end 106 of guidewire 104 extends beyond diffuser 108 , which is positioned at obstruction 102 . The guidewire 104 is constructed of a fiberoptic material, allowing for conduction of radiation during the angioplasty process. As shown in FIG. 2, balloon catheter 206 is inserted into body passageway 200 , circumscribing the guidewire 204 up to the end of the diffuser 210 . When the catheter 206 is properly positioned, balloon 208 is inflated, displacing plaque or other obstruction 202 . After displacement, a light source connected to the proximal end of guidewire 204 is activated, transmitting radiation to diffuser 210 and through balloon 208 . The irradiation stops the re-growth and proliferation of plaque or other obstructions that cause restenosis.
EXAMPLE 2
[0040] [0040]FIG. 3 shows a conventional guidewire 302 circumscribed by a catheter in an affected body passageway 300 . The guidewire 302 is inserted, the distal tip extending a distance beyond the affected area 304 . The balloon catheter 306 is then introduced, circumscribing the guidewire 302 . Optical fibers 308 are contained within the tubular structure of catheter 306 . The angioplasty balloon is positioned at obstruction 304 and inflated. The balloon 310 displaces plaque 304 . A light source connected to the proximal end of optical fibers 308 is activated, transmitting radiation to balloon 310 . Irradiation of the plaque 304 prevents cell growth and regeneration, the causes of restenosis. FIG. 4 shows a cross section, looking down the longitudinal axis, of catheter 400 . Lumens 402 are circular or otherwise shaped for optimal sizing of the catheter structure 400 . Optical fibers 404 are smaller than lumens 402 to allow for movement and prevent cracking or breaking of fibers 404 . At least one lumen 406 exists in the catheter body 400 for circumscribing the guidewire 408 and for transmission of a gas or liquid for inflation of the angioplasty balloon.
Example 3
[0041] In a variation of Example 2 shown in FIG. 5, catheter body 500 is manufactured as a light-conducting polymer. The catheter 500 contains at least one lumen 502 for transmission of gas or liquid to inflate the catheter and to circumscribe the guidewire 504 . The processes of angioplasty and irradiation are similar to Example 2. Radiation is transferred through the light-conducting body of the catheter 500 to an angioplasty balloon in sufficiently homogeneous form to transfer to the angioplasty balloon when inflated, irradiating the obstruction in the body passageway. This homogeneous transmission can be accomplished by use of a simple diffuser. The diffuser transmits radiation from the polymer-based catheter body 500 to the balloon or directly to the obstructed area of the body passageway.
[0042] Having described preferred embodiments of the invention with reference to the accompanying drawings, it is to be understood that the invention is not limited to the precise embodiments, and that various changes and modifications may be effected therein by skilled in the art without departing from the scope or spirit of the invention as defined in the appended claims. | A novel device and method for preventing restenosis and streamlining the angioplasty procedure. The device and method provide a fiberoptic guidewire, or, alternatively, a light-conducting catheter, to decrease the size of the angioplasty device, decrease the overall time of the procedure, and increase the safety of the procedure. The present invention delivers radiation to a sclerotized area after balloon angioplasty treatment to prevent restenosis Radiation delivered via the catheter or fiberoptic guidewire discourages the cell proliferation and cell growth after angioplasty, thereby improving the chances of avoiding restenosis. | 0 |
FIELD OF THE INVENTION
[0001] The invention relates to windows and window frames, and more particularly relates to an impact-resistant window assembly for sheet metal garage doors that can be configured and adapted for use with both insulated and non-insulated doors.
BACKGROUND
[0002] Modern residential garage doors can include a plurality of windows or “lights” that admit light and permit viewing through the doors. Overhead sectional garage doors can include such windows in an uppermost door panel that positions the windows at about eye level when the garage door is closed, for example. Such windows also can be arranged in another door section or in multiple door sections if desired. Such doors can typically include glass panes that are retained and supported within a window opening in a sheet metal door panel by a plastic frame or molding.
[0003] Though such garage door windows can be both attractive and useful, such windows can be subjected to high wind pressure loads and flying objects during severe weather conditions, such as tornados and hurricanes. In some locales where such severe weather conditions are most likely, governments have enacted building codes that require such windows to be resistant to impacts by airborne missiles, such as wind-propelled debris, and to cyclic wind pressure loadings. For example, in Florida, testing application standard TAS 201-94 sets forth test procedures for demonstrating adequate resistance to large missile impact as required by Section 1626 of the Florida Building Code, Building, and TAS 203-94 sets forth test procedures for demonstrating adequate resistance to cyclic wind pressure loading as required by the Florida Building Code and TAS 201-94.
[0004] Unfortunately, the plastic frames and glass panes of typical glazed garage doors fail under such severe impact and pressure conditions. Accordingly, there is a need for an impact-resistant window assembly for garage doors that meets the demanding criteria set forth in the most stringent modern building codes and standards. As used herein, the term “impact-resistant” means resistant to failure when subjected to impacts from airborne missiles which, under identical conditions, would cause a conventional plain glass window pane supported in a door by an all-plastic window frame to fail.
[0005] Metal garage doors generally are produced in two general types: insulated doors and non-insulated doors. As used herein, the term “insulated” means including added thermal insulation having a resistance to heat transfer that is substantially greater than the resistance to heat transfer characteristic of steel or aluminum. Insulated metal garage doors typically include a plurality of sheet metal door panels backed by a panel of thermally insulating material. For example, each thin metal door section may be backed by polymeric foam panel having a thickness of about one-two inches. Because the sheet metal door panels are highly thermally conductive, the sheet metal skins of such doors do little to resist heat transfer through the door. The insulating panels act to block the transfer of heat through the door that otherwise would occur. Thus, such insulated garage doors are especially useful for installation in entryways to garages or other spaces that are actively heated or cooled. In contrast, non-insulated garage doors essentially include only the sheet metal door panels, and are best-suited for installation in entryways to garages or other spaces that are not actively heated or cooled. Apart from their insulating panels, insulated metal garage doors can be substantially identical to non-insulated metal garage doors.
[0006] When an insulated metal garage door includes at least one glazed panel, the associated insulating panel that backs the sheet metal face skin necessarily includes one or more window openings that align with corresponding openings in the sheet metal face skin. Because the insulating panels typically are constructed of polymeric foam materials that are soft and brittle and can be easily damaged or broken, the portions of an insulating panel that surround a window opening are vulnerable to damage if left unprotected, and require support on the back of the door panel. Accordingly there is a need to support and shield the exposed edges of an insulating panel that surround a window opening in an insulated metal garage door panel. Of course, because non-insulated metal door panels don't include insulating panels, there is no need to support and shield the edges of an insulating panel that surround a window opening in such a door panel.
[0007] Accordingly, there is a need for a universal impact-resistant window assembly for a metal garage door that can be adapted for use in door sections both with and without an insulation panel backing the section's sheet metal face skin. When used in an insulated door section, such a universal window assembly should be configured to support and shield the edges of an insulating panel that border an associated window opening in the door section.
SUMMARY
[0008] In one embodiment, the invention includes a universal impact-resistant window assembly for a garage door of a type having a sheet-metal face skin. The window assembly is adaptable for installation in both insulated and non-insulated garage doors. The window assembly includes an impact-resistant window pane, and an interior metal frame configured to be installed within and around a window opening in the sheet-metal face skin. An exterior metal frame is configured to be installed within and around the window opening in the sheet-metal face skin, and is configured to cooperate with the interior metal frame to engage portions of the sheet-metal face skin that surround the window opening, and to retain the window pane therebetween. An exterior trim member is configured to substantially cover exterior portions of the exterior metal frame, and an optional interior trim member is configured to substantially cover interior portions of the interior metal frame. The interior trim member includes a rear flange configured to at least partially support an insulating panel proximate to the sheet-metal face skin when the window assembly is installed in an insulated door.
[0009] In another embodiment, an impact-resistant window assembly is adapted for installation in a window opening in an insulated garage door or a non-insulated garage door, such door being of a type having a sheet metal face skin with a window opening therein. The window assembly includes a window pane, and an interior metal frame having a forward lip and a rear lip, the rear lip being inwardly offset from the forward lip. The window assembly also includes an exterior metal frame having an exterior lip, a rear land that is inwardly offset from the exterior lip, and a pane-retaining lip. The interior metal frame is disposed around the window opening on an interior side of the face skin, the forward lip of the exterior metal frame is disposed around the window opening on an exterior side of the face skin, and the interior metal frame is connected to the exterior metal frame. Portions of the sheet metal face skin are sandwiched between the forward lip and the exterior lip, and the window pane is retained within the window opening between the rear lip and the pane-retaining lip.
[0010] Another embodiment of the invention includes a garage door having at least one impact-resistant window assembly for selective installation in either an insulated sheet metal door panel or a non-insulated sheet metal door panel. The window assembly includes an impact-resistant window pane, and a frame arranged and constructed to securely support the window pane within a window opening in the sheet metal door panel. An interior member is configured to be optionally removably connected to an interior portion of the frame, and includes a rearwardly extending flange arranged and constructed to at least partially support one or more insulation panels proximate to an interior side of sheet metal door panel of an insulated sheet metal door panel. The interior member can be excluded from the window assembly when the window assembly is installed in a non-insulated sheet metal door panel without one or more insulation panels.
[0011] These and other aspects of the invention will be apparent from a reading of the following detailed description, together with the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] FIG. 1 is an exterior elevation view of a metal sectional overhead door including a plurality of universal impact resistant window assemblies according to the invention.
[0013] FIG. 2 is an interior elevation view of a non-insulated glazed door panel of the garage door shown in FIG. 1 .
[0014] FIG. 3 is an interior elevation view of an insulated glazed door panel of the garage door shown in FIG. 1 .
[0015] FIG. 4 is a cross-sectional view of the non-insulated glazed door panel shown in FIG. 2 taken along section line 4 - 4 .
[0016] FIG. 5 is a cross-sectional view of the insulated glazed door panel shown in FIG. 3 taken along section line 5 - 5 .
[0017] FIG. 6 is an interior elevation view of an impact-resistant window assembly installed in a non-insulated glazed door panel like that shown in FIG. 2 .
[0018] FIG. 7 is a cross-sectional view of the impact-resistant window assembly shown in FIG. 6 taken along section line 7 - 7 .
[0019] FIG. 8 is a cross-sectional view of the impact-resistant window assembly shown in FIG. 6 taken along section line 8 - 8 .
[0020] FIG. 9 is an interior elevation view of an impact-resistant window assembly installed in an insulated glazed door panel like that shown in FIG. 3 .
[0021] FIG. 10 is a cross-sectional view of the impact-resistant window assembly shown in FIG. 9 taken along section line 10 - 10 .
[0022] FIG. 11 is a cross-sectional view of the impact-resistant window assembly shown in FIG. 9 taken along section line 11 - 11 .
[0023] FIG. 12 is a perspective view of an interior metal frame portion of the window assemblies shown in FIGS. 6-11 .
[0024] FIG. 13 is a cross-sectional view of the interior metal frame shown in FIG. 12 taken along section line 13 - 13 .
[0025] FIG. 14 is a cross-sectional view of the interior metal frame shown in FIG. 12 taken along section line 14 - 14 .
[0026] FIG. 15 is a perspective view of an exterior metal frame portion of the window assemblies shown in FIGS. 6-11 .
[0027] FIG. 16 is a cross-sectional view of the exterior metal frame shown in FIG. 15 taken along section line 16 - 16 .
[0028] FIG. 17 is a cross-sectional view of the exterior metal frame shown in FIG. 15 taken along section line 17 - 17 .
[0029] FIG. 18 is a perspective view of a corner portion of the exterior metal frame shown in FIGS. 15-17 .
[0030] FIG. 19 is a perspective view of an exterior trim member portion of the window assemblies shown in FIGS. 6-11 .
[0031] FIG. 20 is a cross-sectional view of the exterior trim member shown in FIG. 19 taken along section line 20 - 20 .
[0032] FIG. 21 is a perspective view of an interior trim member portion of the window assembly shown in FIGS. 9-11 .
[0033] FIG. 22 is a cross-sectional view of the interior trim member portion shown in FIG. 21 taken along section line 22 - 22 .
DETAILED DESCRIPTION
[0034] FIG. 1 shows a metal sectional overhead garage door 10 , 20 according to the invention. In one embodiment, the door is a non-insulated door 10 that includes at least one glazed door section 12 , and a plurality of non-glazed door sections, 14 , 16 and 18 . The glazed door section 12 includes a sheet metal face skin 15 having a plurality of window openings or apertures in which impact-resistant window assemblies 100 are installed. In another embodiment also shown in FIG. 1 , the door can be an insulated door 20 that includes at least one glazed door section 22 , and a plurality of non-glazed door sections, 24 , 26 and 28 . The glazed door section 22 includes a sheet metal face skin 25 having a plurality of window openings or apertures in which impact-resistant window assemblies 200 are installed. As discussed in detail below, the window assemblies 100 , 200 can have a substantial number of common components, such that in a first configuration 100 , the window assembly can be installed in a non-insulated door 10 , and in a second configuration 200 , the window assembly can be installed in an insulated door 20 .
[0035] FIG. 2 shows a rear or interior view of a glazed non-insulated door panel 12 . As shown in FIGS. 2 and 4 , the interior surface of the sheet metal face skin 15 is exposed, and the window assemblies 100 are supported within spaced apertures in the face skin 15 . FIG. 3 shows a rear or interior view of a glazed insulated door panel 22 . As shown in FIGS. 3 and 5 , the interior surface of the sheet metal face skin 25 is substantially covered by one or more insulation panels 30 , including portions of the face skin 25 around each of the window assemblies 200 . As shown in FIG. 5 , a rear portion 170 of each window assembly 200 is configured to cover and protect inside edges of the insulation panel that surround the window assembly 200 , and to at least partially support and retain the insulation panel 30 behind the sheet metal face skin 25 .
[0036] Details of one embodiment of an impact-resistant window assembly 100 for use in a non-insulated sheet metal door section 12 are shown in FIGS. 6-8 , and are described below. As shown in FIG. 7 , the window assembly 100 is configured to be assembled within an aperture 17 in a thin sheet metal face skin 15 of a door section 12 . The window assembly 100 includes an impact-resistant window pane 102 , an exterior metal frame 120 , an interior metal frame 106 , and an exterior trim member 130 . The impact-resistant window pane 102 can be laminated glass, polycarbonate, or any other substantially transparent impact-resistant material or combination of materials.
[0037] One embodiment of an interior metal frame 106 for use in an impact-resistant window assembly 100 according to the invention is shown in FIG. 7 and in FIGS. 12-14 . In this embodiment, the interior metal frame 106 has a substantially rectangular shape, and includes a forward lip 110 , a rear lip 112 , and an outer wall 119 connecting the forward lip 110 to the rear lip 114 . As shown in FIG. 12 , the interior metal frame 106 can be constructed from a single piece of sheet material. A plurality of spaced screw holes 114 can be located in the rear lip 112 . The interior metal frame 106 can be constructed of steel, such as galvanized low-carbon commercial steel, or any other suitable material. When constructed of steel, the frame 106 can have a nominal thickness of at least about 0.03 inch.
[0038] One embodiment of an exterior metal frame 120 for use in an impact-resistant window assembly 100 according to the invention is shown in FIG. 7 and in FIGS. 15-18 . In this embodiment, the exterior metal frame 120 has a substantially rectangular shape, and includes an exterior lip 126 , a rear land 122 , and a pane-retaining lip 124 . As shown in FIGS. 16 and 17 , a plurality of screw holes 128 can be provided in the rear land 122 . As shown in FIG. 18 , the exterior metal frame 120 can be constructed of a pair of opposed vertical members 123 and a pair of opposed horizontal members 126 . Each end of each vertical member 123 can be joined to an end of a horizontal member 126 by tabs 127 a, 127 b. As shown in FIG. 18 , the tabs 127 a, 127 b can be arranged to overlap adjacent portions of an exterior lip 126 and a pane-retaining lip 124 , respectively, and connected thereto by one or more spot welds, for example. Alternatively, the exterior metal frame 120 can be formed from a single piece of material. Like the interior metal frame 106 , the exterior metal frame 120 can be constructed of steel, such as galvanized low-carbon commercial steel, or any other suitable material. When constructed of steel, the frame 120 can have a nominal thickness of at least about 0.03 inch.
[0039] As shown in FIG. 7 , the interior frame 106 can be positioned around a window opening 17 in the sheet metal face skin 15 of a door panel 12 such that the forward lip 110 abuts the interior surface of the face skin 15 . As also shown in FIG. 7 , the exterior metal frame 120 can be positioned such that the rear land 122 and pane-retaining lip 124 are within the window opening 17 , and the exterior lip 126 abuts the exterior surface of the of the face skin 15 around the opening 17 . As shown in FIG. 8 , a first plurality of screws 160 can be engaged through aligned screw holes 114 and 128 in the frames 106 , 120 , thereby securely connecting the frames together. As shown in FIGS. 7 and 8 , the forward lip 110 of the interior frame 106 and the exterior lip 126 of the exterior frame 120 cooperate to sandwich edges of the face skin 15 around the opening between the two frames 120 , 106 , thereby securely supporting the connected frames 106 , 120 in the opening 17 .
[0040] As also shown in FIGS. 7 and 8 , when the interior frame 106 and exterior frame 120 are assembled in the opening 17 as described above, the rear lip 112 of the interior frame 106 and the pane-retaining lip 124 of the exterior frame 120 cooperate to receive and support a window pane 102 therebetween. A first bead of an adhesive material 140 can be placed between the rear lip 112 and the window pane 102 , and a second bead of adhesive can be placed between the pane-retaining lip 124 and the window pane 102 . The beads of adhesive 140 , 142 affix the window pane 102 to the assembled metal frames 106 , 120 , and also form a substantially air-tight seal around the window pane 102 . The assembled metal frames 106 , 120 are sized and configured to transmit substantial impact loads and substantial pressure loads on the window pane 102 to the surrounding sheet metal face skin 15 .
[0041] As shown in FIGS. 7 and 8 , the window assembly 100 can further include an exterior trim member 130 . Details of one embodiment of an exterior trim member 130 are shown in FIGS. 19 and 20 . In the embodiment shown, the exterior trim member 130 has a substantially rectangular shape, and includes an inner edge portion 134 and an outer edge portion 136 . As shown in FIGS. 7 and 20 , the exterior trim member 130 also can include a plurality of rearwardly extending bosses 132 . As shown in FIG. 7 , the bosses 132 are configured to inwardly extend to the rear land 122 of the exterior metal frame 120 , and to be secured to the connected exterior and interior metal frames 120 , 106 by a second plurality of screws 150 that are received in aligned screw holes 114 , 128 and bosses 132 . As shown in FIGS. 7 and 8 , when the exterior trim member 130 is connected to the metal frames 106 , 120 , the outer edge portions 136 contact an exterior surface of the face skin 15 of the door panel 12 , and the inner edge portions contact an exterior surface of the window pane 102 . Accordingly, the exterior trim member covers the exterior metal frame 130 , hides the exterior metal frame from view from the outside of the door panel 12 , and provides a finished appearance to the exterior outer edges of the window 100 . In a preferred embodiment, the exterior trim panel 130 is constructed in a single piece from a molded polymeric material, such as high impact polystyrene, or the like. Preferably, exterior portions of the exterior trim member 130 include attractive architectural surface contours.
[0042] As shown in FIGS. 9-11 , an interior metal frame 106 , an exterior metal frame 120 , a window pane 102 , and an exterior trim member 130 as described above can also be used in an impact-resistant window assembly 200 installed in an insulated sheet metal door panel 22 having a face skin 25 and one or more thick insulation panels 30 . In this embodiment, the window assembly 200 additionally includes an interior trim member 170 . Details of one embodiment of the interior trim member 170 are shown in FIGS. 21 and 22 . In this embodiment, the interior trim member 170 includes a forward flange 174 and a rear flange 172 . The forward flange 174 can include a plurality of spaced screw holes 176 extending therethrough. In a preferred embodiment, the interior trim member 170 is constructed in a single piece from a molded polymeric material, such as high impact polystyrene, or the like.
[0043] As can be seen by comparing FIGS. 10 and 11 to FIGS. 7 and 8 , the interior metal frame 106 , the exterior metal frame 120 , and the window pane 102 can be assembled together in a window opening 19 in a sheet metal face skin 25 of an insulated door panel 22 in a manner that is identical to the assembly described above for installation in an opening 17 in a face skin 15 of a non-insulated door panel 12 (as shown in FIGS. 7 and 8 ). In particular, the metal frames 106 , 120 are connected together in the opening 19 by a first plurality of screws 160 . When so connected, the forward lip 110 of the interior frame 106 and the exterior lip 126 of the exterior frame 120 again cooperate to sandwich edges of the face skin 25 around the opening 19 between the two frames 120 , 106 , thereby securely supporting the connected frames 106 , 120 in the opening 19 . In addition, the rear lip 112 of the interior frame 106 and the pane-retaining lip 124 of the exterior frame 120 again cooperate to receive and support a window pane 102 therebetween. As described above, a first bead of an adhesive material 140 can be placed between the rear lip 112 and the window pane 102 , and a second bead of adhesive can be placed between the pane-retaining lip 124 and the window pane 102 .
[0044] In this window assembly 200 , both the exterior trim member 130 and the additional interior trim member 170 are connected to the adjoined metal frames 106 , 120 by a third plurality of screws 180 . The screws 180 are received in holes 176 in the interior trim member 170 , aligned holes 114 and 128 in the connected metal frames 106 , 120 , and bosses 132 of the exterior trim member. As shown in FIGS. 10 and 11 , when thus assembled in the opening 19 , the outer edge portions of the exterior trim member contact the face skin 25 , and the rear flange 172 of the interior trim member 170 contacts back surfaces of the insulation panel(s) 30 . Accordingly, the interior trim member 170 and the exterior trim member 130 cooperate to sandwich the face skin 25 and the insulating panel 30 therebetween, and to at least partially secure the insulation panel 30 against a rear surface of the face skin 25 . In addition, the rear flange 172 covers and protects the fragile edges of the insulation panel 30 that surround the window opening 19 . The forward flange 174 of the interior trim member 170 substantially covers interior portions of the interior metal frame 106 , thus shielding the interior frame 106 from view. The exterior trim member 130 and interior trim member 170 combine to provide a finished appearance to the outer edges of the window 200 on both the inside and outside of the glazed door panel 22 .
[0045] The above description of various embodiments of the invention is provided to illustrate particular aspects and features of the invention, and not to limit the invention thereto. Persons of ordinary skill in the art will recognize that certain changes and modifications can be made to the described embodiments without departing from the invention. For example, though the impact-resistant window assemblies have been shown and described as being rectangular in shape, the windows can have substantially any polygonal or other outer shape. All such changes and modifications are intended to be within the scope of one or more of the appended claims. | A universal impact-resistant window assembly for a garage door of a type having a sheet-metal face skin includes a window assembly adaptable for installation in both insulated and non-insulated garage doors. The assembly includes an impact-resistant window pane, and an interior metal frame installed within and around a window opening in the sheet-metal face skin. An exterior metal frame is installed within and around the window opening in the sheet-metal face skin. The exterior metal frame cooperates with the interior metal frame to engage portions of the sheet-metal face skin that surround the window opening, and to retain the window pane. An exterior trim member substantially covers exterior portions of the exterior metal frame, and an optional interior trim member substantially covers interior portions of the interior metal frame. A rear flange of the optional interior trim member at least partially supports an insulating panel proximate to the sheet-metal face skin when the window assembly is installed in an insulated door. | 4 |
This application claims the benefit of the filing of the U.S. Provisional Patent Application Ser. No. 60/032,947, filed Dec. 9, 1996.
BACKGROUND OF INVENTION
A Blowout Preventer (BOP) is a critical feature of undersea drilling operations. The functions of a BOP, such as annular preventers and choke and kill valves, are operated by a hydraulic control system. Since the hydraulic fluid is piped from the surface, response time for deep water operations is slow due to the distances involved. As a result, an electronic or multiplex control pod is located on the BOP to effect a quicker control response. Mechanical problems or maintenance requirements occasionally require a pod to be removed and replaced. Therefore, reliability and easy maintainability are premium characteristics of a control pod.
SUMMARY OF THE INVENTION
The invention relates to a blowout preventer control system which is surrounded by a plurality of enclosure plates and comprises an electronics package which receives a control signal and relays it to a plurality of solenoids mounted within a solenoid housing. The solenoid housing also contains a non-conductive fluid, a pressure equalization bladder which is filled with sea water, and a plurality of transducers that are mounted in an accessible position within the solenoid housing wherein a transducer can be removed from the solenoid housing without disturbing the non-conductive fluid. A plurality of shear seal valves are also mounted on the solenoid housing.
The invention further comprises a plurality of seal subs which are accessible without removal of other elements of the apparatus, at least one junction plate with a lost motion float, and a plurality of adjustable length pipe spools which receives the hydraulic pressure from the seal subs. A pipe spool comprises a pipe with two threaded ends, at least one length adjustment nut which is attached to each threaded end of the pipe, a captive flange which fits over each length adjustment nut, and a plurality of bolts which fix the captive flange in place over the length adjustment nut.
The invention further comprises an internal stab which receives the hydraulic pressure from the pipe spools and transfers it through a plurality of fixed internal conduits to the blowout preventer. A plurality of pressure activated packer seals connect the fixed internal conduits of the stab to the blowout preventer. A pressure activated packer seal comprises a circular metal support with an interior ledge, an exterior slot and a bottom channel, a rubber seat attached around the interior ledge, a rubber tapered flange attached around the exterior slot, and a metal wave spring attached around the bottom channel. Also included in the stab is an electrical cable which extends through the stab, an electrical connector which connects the electrical cable to the blowout preventer, and a connector guide which correctly aligns the electrical connector without rotation. The connector is aligned by limiting the movement of the electrical connector to two perpendicular axes which are parallel to the blowout preventer. The connector guide comprises a guide frame, an upper connector member with formed flats, which is movably mounted within the guide frame, a lower connector member with formed flats, which is movably mounted within the guide frame.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a typical deep sea drilling operation.
FIG. 2 shows a perspective view of a BOP control pod.
FIG. 3 shows a frontal view of a BOP control pod with enclosure plates.
FIG. 4 shows a frontal view of a BOP control pod connected to the BOP receiver block.
FIG. 5 shows a frontal view of the pod base block and the stab connected to the riser receiver block and the BOP receiver block.
FIG. 6 shows a frontal view of a BOP control pod with the stab disengaged from the BOP receiver block.
FIG. 7 shows a frontal view of a BOP control pad with the stab disengaged from the BOP receiver block and the pod base block disengaged from the riser receiver block.
FIG. 8 shows a frontal view of a pipe spool connected to a sub plate mounted valve.
FIG. 9a shows an overhead view of a pressure energized packer seal
FIG. 9b shows a cross-sectional view of a pressure energized packer seal.
FIG. 10 shows a cross-sectional view of a transducer.
FIG. 11a shows a frontal view of a stab with an engaged electrical connector.
FIG. 11b shows an partial overhead view of a BOP receiver block with an electrical connector.
FIG. 12a shows an electrical connector with a connector guide.
FIG. 12b shows an exploded view of a connector guide.
FIG. 12c shows an overhead view of a connector guide.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The preferred embodiments of the invention are described with reference to the accompanying figures. Like references in different figures are shown with the same numeral.
The present invention relates to subsea control pods, such as shown in U.S. Pat. Nos. 3,460,614, 3,701,549, and 3,817,281 for controlling various subsea wellhead drilling functions, such as the operation of blowout preventers. Thus, the present invention is particularly used in pressure control and is suitable for deep water drilling.
FIG. 1 illustrates a typical under sea drilling operation. The BOP 12 extends through the lower marine riser package 14 (LMRP). The LMRP is separable into an upper stack 15 (shown in FIG. 4) and a lower stack 17 (shown in FIG. 4). There are times when the upper stack of the LMRP 14 must be disconnected from the lower stack which remains attached to the wellhead. The lower stack bore is then closed with shear rams and the choke and kill valves are closed. The connections for a control pod 10, located on the side of the LMRP 14, are retracted in order to prevent damage to the control pod 10.
The operation is arranged with dual identical control systems for redundancy purposes. A system may be controlled through a central control unit 16 (CCU) or a control panel 18. The control signals are sent to the pod 10 through a cable which is spooled on a mux reel 24 and extends to the pod. The hydraulic fluid for the system is supplied by a hydraulic pump unit 26 with its surface accumulators 28. The fluid is transferred to the control pod 10 through a "hot line" which is spooled on a hot line reel 20 during the movement and return of the LMRP. The main hydraulic fluid supply line is a rigid supply conduit which is incorporated into the riser once the BOP is placed.
FIG. 2 illustrates a perspective view of a subsea control pod 10 in accordance with the present invention. In a preferred embodiment, the pod 10 includes an upper electronics module 30 mounted atop a lower hydraulic module 32. A hydraulic cylinder 64 (not shown in FIG. 2) is mounted at the center of the lower module 32 for lowering a male member, or stab 34 into engagement with the BOP receiver block 74 (not shown in FIG. 2) which is mounted on the lower stack of the BOP 12. In FIG. 2, the stab 34 is shown in the disengaged, retracted position. In FIG. 4, the invention is displayed with the stab 34 in the engaged, lowered position.
One significant advance provided by the present invention is the provision of an integrated stab 34 and pod base block 72 design, which are shown more particularly in FIG. 5. Currently, the art utilizes separate stab members, apart from the main pod, that are each lowered and retracted. Subsea pods utilizing such systems require that bundles of hoses be connected between the main pod and these separate stabs for hydraulic communication.
With the present invention, a single stab 34 is built into the pod 10. Thus, it eliminates the hoses, simplifies the overall system, and improves reliability. Even though the pod 10 has a large footprint from the integration of functions, the invention eliminates other devices that are outside of the pod 10 and is therefore a very efficient way of communicating from the pod 10 on the LMRP 14 to the BOP receiver block 74 mounted on BOP receiver stack with a single retractable stab 34. In effect, the single stab 34 functions with the pod base block 72 like a big, quick disconnect.
The retractable stab 34 does away with the need for hoses to provide inter-connections between the pod components through the use of a plurality of bores, or conduits 58 that are machined into it, as shown particularly in FIG. 5. The stab 34 is designed to work with the specially designed pod base block 72 which also has internal conduits 58 that terminate in upper sealed points for engagement with the stab conduits. Thus, the pod base block 72 includes inboard conduits for operation of the BOP stack functions, and outboard conduits for operation of the riser functions. The outboard side 78 sealingly engages the riser receiver block 70, and the inboard side 76 sealingly engages the upper stab when the stab 34 is lowered. The stab 34, in turn, sealingly engages the BOP receiver block 74 at the bottom.
FIG. 3 shows the control pod with enclosure plates 60 attached to the lower module 32. The plates serve to enclose the hydraulic module 32 so that the expended hydraulic fluid is contained and expelled only through the module vents 62. This keeps the expended fluid on the exhaust side of the hydraulic control valves and in turn keeps control fluid in contact with the vented side of the BOP and stack valves. Contact with the expended fluid is much preferred over contact with sea water. These features also give the pod the flexibility to be arranged as a "closed system" where the expended hydraulic fluid is recovered by the system. Also shown is a protective screen 61 which protects the module from collecting trash when the stab 34 is extended.
As shown in FIGS. 4 and 5, all the fluid piping comes into an intermediate, pod base block 72 so there are no moving pipes or hoses on the pod 10. The pipes, or pipe spools 68, are fixed and feed upper seal points on the pod stab 34 when the stab is in the extended position, as shown in FIG. 4. The hydraulic fluid communicated through the upper seal points flows through the conduit 58 in the stab 34, and out the lower seal points to enter the BOP receiver block 74 for activating various stack functions. The hydraulic cylinder 64 jacks the pod stab up and down. The fixed pipe spools 68 connected to the pod base block 72 are fed from above by valves in the pod 10 itself, as discussed further below.
As shown in FIG. 5, the junctions between the conduits 58 from the stab 34 and both block are sealed with pressure energized packer seals 80. FIGS. 9a and 9b show a pressure energized packer seal 80 which comprises a circular rigid support 94 with a flexible seat 92 attached around its interior. The outer edge of the rigid support contacts the seal pocket 81. This provides support to keep an extruding gap from forming between the packer seal and the pocket. The flexible seat 92 extends above the rigid support 94 which allows a compression seal to be formed when pressure is applied. An outwardly tapered flange 96 is attached around the exterior of the rigid support 94. Holes 95 are present are various intervals within the rigid support 94. This allows the flexible seat 92 and tapered flange 96 to make contact when the packer seal is being molded. Also, a wave spring 98 is fitted around the base of the rigid support 94. A wave spring 98 is a circular strip with periodic undulations which allow some elastic compression. The rigid support 94 and the wave spring 98 are usually metal, but any other suitable materials could be used. The preferred material is a nickel, aluminum and bronze alloy which prevents galling. The flexible seat 92 and the tapered flange 96 are usually rubber, but any other suitable material could be used.
The key to the pressure energized packer seal 80 is the tapered flange 96. A dynamic seal forms when pressure is exerted on the tapered flange 96. The flared surface is forced out against the interior diameter of the seal pocket 81 in the end of the conduit 58. This device will maintain a tight seal should any movement of the structure take place which could cause the seals to leak.
FIGS. 4 and 5 show the pod 10 being engaged to the riser receiver block 70 through the pod base block 72 and the BOP receiver block 74 through the pod stab 34. Any time the rig operators are going to disconnect the riser package and leave the lower BOP stack on the wellhead, they retract all stabs 34 before they disconnect the riser. The tapered stab 34 must be retracted by its hydraulic cylinder 64 before disconnecting the riser package from the lower BOP stack. Fully retracting the stab disengages it from the BOP receiver block as shown in FIG. 6. The stab 34 is designed to be fully retracted into the body of the lower pod module so as to provide ready access to the pod base block's pressure energized packer seals 80 for servicing. Once the stab 34 is fully retracted, the pod base block 72 is hydraulically disconnected from the BOP receiver block 74 which remains attached to the riser package. When the pod base block 72 is disconnected, the entire pod 10 is disengaged from the riser package as seen in FIG. 7. At this point, there are no stabs extending downward into the riser package.
The pod 10 per se is not intended to be retrievable subsea, but it's designed to be a quick change unit so that when installed, it is bolted in place as shown in FIG. 3. The pod 10 is mounted by eight bolts 90 on each side which fix the whole pod structure to the riser receptacle assembly. While bolts are shown for an attachment mechanism, any other suitable means could be used including clamps for use in a recoverable control pod. Thus, by removing the bolts 90, one pod can be taken off the riser package and another one can be bolted in its place if necessary. For example, if a particular user had three pods, there would only be two active pods on the BOP stack. In the event that a malfunction was identified in one of the active pods, that pod could be removed and replaced with the spare on deck. Thus, drilling operations can be resumed fairly quickly, while the malfunctioning pod was being serviced.
Aside from the mounting bolts 90, there are five electrical cables that must be disconnected to isolate the pod from the LMRP. First, there is the main electrical cable, or main umbilical, which is carried on a reel on the surface deck, and which basically operates the pod by enabling communication with the panels and electronics on the surface. Thus, the main umbilical cable provides all essential electrical power and signal communications. The main umbilical connector 52 must be disconnected when recovering the pod from the LMRP riser package. When the cable is retrieved back to the surface, it is spooled up on the reel so the main umbilical connector 52 can be disconnected from the upper module 30. At this point, the pod 20 is effectively isolated from the surface and must be retrieved. The main umbilical connector may be a "make and break" connector for a recoverable pod configuration.
Also, there is space for four external cable connections 54 that are mounted to the upper pod module 30, as shown in the plan view of FIG. 2. These cables enable the recording of certain data, such as pressure and temperature on the riser package. In other words, they are data acquisition and possible operation cables for temperature, pressure, and other variables, and also communicate with the electronics on the surface deck.
Once the cables are disconnected, and the pod 10 is fully disengaged, it can be lifted off the riser receiver block 70 so that the replacement pod can be bolted in its place. Virtually all subsea systems have at least two pods for redundancy.
As implied above, the pod 10 itself is a modular unit including an upper electronics module 30 that can be separated from a lower hydraulic module 32. Thus, a rig operator could replace the hydraulic module 32 by disconnecting the electronics module 30 at the junction plate 38, and moving the electronics module 30 so that the replacement could occur. None of the electrical components would have to be disturbed. The modules are designed for optimum adaptability, so that virtually any electronic module will mount to any hydraulic module, regardless of specific configurations.
With reference now to FIG. 4, the hydraulic regulators 39 and sub-plate mounted (SPM) 66 valves that feed the pipe spools 68 connected to the pod base block 72 are shown with the lower module 32. The pipe spools 68 are basically sub seals 36, in the form of tubing with O-rings 82 on each end. The spools are threaded for connection at both ends, which provides an adjustable-length inter-connection between the SPM valves and the pod base block for either outboard riser functions or inboard BOP functions.
As shown in FIG. 8, the pipe spool 68 comprises a pipe 83 with two threaded ends 88. A height adjustment nut 84 is screwed on each of the ends until the desired space apart of the pipe 83 from the connections is achieved. A captive flange 86 is fixed in place over the height adjustment nut 84 with bolts 90. This minimizes binding of the connections of the pipe spool to the SPM valves and the pod base due to the tolerance between the members.
The hydraulic supply manifolds are mounted essentially on the rails, or the frame members of the pod 10. Special adjuster nuts 84 allow for the positioning of the SPM valves on the manifolds which are fixed in place by adjustment of the adjuster nuts 84, so that everything is properly leveled. Thus, when everything is tightened, none of the components are put in a bind.
The SPM valves are typical sizes, 11/2", 1", and 1/2", and each have the same mounting philosophy as the manifolds. The valves are mounted through 4-bolt flanges (not shown) which are arranged in a rectangular pattern. The hydraulic output of each SPM valve 66 is directed through one of the pipe spools 68. As mentioned above, the lengths of the pipe spools are adjustable through their threaded ends. The spool length doesn't actually change, but the adjustment of where it "shoulders" and is tightened up makes its effective length adjustable.
Referring back to FIG. 2, the lower hydraulic module 32 is shown in one embodiment as 55" in height, and the upper electronics module 30 is shown as 603/4" tall. The electronics packages 48 are housed in the tall can in the center of the upper module 30, while the shorter can contains transformers 50.
Solenoid-operated shear-seal valves 41 are mounted in the solenoid housings 42 at the outer portions of the electronics module 30. The solenoids (not shown) mount on the inside of these enclosures. The shear-seal valves 41 mount opposite the solenoids on the outer portion of the solenoid housing 42. These valves are electro-hydraulic pilot valves. Thus, when an operator presses a button on a panel at the surface, it instructs the surface electronics to send a signal down to the electronics package to fire a particular solenoid. Then, there is some electronic verification communicated back and forth, and the solenoid is fired. When this happens, hydraulic pressure is directed from the shear-seal valve 41 associated with that solenoid down through the junction plate 38, or seal sub interface, to the appropriate SPM valve 66 in the lower hydraulic module 32. Thus, pressure is directed from the shear-seal valve 41 through the junction plate 38 down to the hydraulic pilot, the SPM valve 66.
The junction plate 38 represents a break point between the upper and lower modules. Tubing extends from the shear-seal valves 41 down to the seal subs 36, and complementary tubing extends from the seal subs 36 through the hydraulic module 32, down to the SPM valves 66. If and when the modules are disconnected, such as to bring a replacement module in, the tubing connections will already be made up in the replacement module.
The electronics are designed to have a "table" format in which each solenoid and transducer has a specific address, so the electronics can communicate with the device at that address or read back pressure from the transducer from its address. Typically, there are some functions that are programmed to be performed in sequences. For example, emergency disconnect sequences are set up for leaving the stack as quickly as possible. There are certain hydraulic functions that have to be performed to do that, which can be pre-programmed. Thus, when the operator executes the automatic disconnect sequence by pressing the appropriate button on a panel, the software and electronics performs the functions in accordance with the program. However, the sequence can be changed by the operator at any time. In other words, the operator can add functions that weren't in the program before, or he can take things out, to change the pre-set sequence.
FIG. 2 also shows the transmitters, or transducers 40, that are repairable in place. The transducers 40 are shown on the bottom row of the electronics module 30, in the side elevational view. There are ten on each side of the pod. The transducers 40 convert hydraulic pressure to an analog signal, and are shown in greater detail in FIG. 10. Dual O-rings 82 provide a seal down on the outer diameter of the transducer 40 where it fits into the solenoid housing 42. All electrical connections are on the inside of the solenoid housing 42, which is filled with a non-conductive fluid. A bladder member (not shown) is mounted atop the housing 42 inside the solenoid housing cover 44 and allows the entry of sea water into the bladder to pressure-compensate the housing fluid with the sea head. In this manner, all electrical devices are contained in a "friendly" fluid.
There are dual O-ring seals that interface at multiple areas in the solenoid housing 42. Each solenoid has dual O-rings 82. The transducers 40 also have dual O-rings 82, as do the enclosure plates 60, the solenoid housing cover 44, and the seal subs 36 that interface between the housing and electronics modules. Additionally, the devices that are in the solenoid housing 42 are designed to work even if the housing has sea water in it. So the system has multiple backups, through dual seals, a friendly fluid, and electrical components that will continue to work if exposed to water.
Referring again to FIG. 10, the right hand portion of the transducer is mounted inside the solenoid housing with the friendly fluid. The left hand portion is outboard, and has pressure connection points for tying into the component whose pressure is to be measured. Orientation pins 116 are used to ensure proper alignment of the transducer. An Ashcraft sensor 114 or the like is welded to the transducer body. The wires from that sensor terminate in a connector that plugs in. The connector, or penetrator, has four pins on each end (not shown). Thus, the transducer has a make-and-break stab connection on either side of the penetrator.
The interior chamber 100 of the outer portion of the transducer 40 is sealed at one atmosphere. The exterior portion 101 of the transducer 40 inside the solenoid housing 42 is at sea head pressure. Again, there are dual O-rings 82 here that are exposed to sea head differential. The inner portion of the transducer 40 is exposed to hydraulic pressure plus the hydraulic head, so there is quite a bit of differential across this joint. There is an orientation pin on the transducer cap that only allows the sensor portion to be installed in one way. The internal connector is keyed so that it only fits one way. The penetrator has a pin so that it's also oriented one way. As a result, all the components can be made up with confidence that the alignment is correct. The construction of the transducer 40 allows it to be pulled out of the solenoid housing 42 and replaced without draining the fluid from the housing. Replacement of the body portion or the penetrator would require draining the housing.
The solenoids do not have this feature. The solenoids have a boot-type seals over two single pin connectors that essentially pressure energize the seal, but some of the fluid will necessarily be lost from the housing during the change out of a solenoid. However, the shear-seal portion opposite the solenoid can be loosened without disturbing the fluid, and the shear-seal is the most likely the part that will need service. For example, maybe an O-ring might have failed or something similar. If the solenoid must be removed, the fluid will be drained only to the level of the solenoid.
The prior art transducers are mounted on the inside of the housing just like the solenoid, and the pressure connections come from the outside. So if anything happens to a prior art transducer, the solenoid housing must be drained to pull the transducer from the inside. This of course entails a lot of work. By contrast, if something happens to the sensing element of the present invention, the removal of four screws enables the inner transducer housing to be pulled out and replaced without having to disturb the fluid contents of the solenoid housing.
The solenoid shear-seal valves 41 are seal sub mounted, so taking those off is also just a matter of removing a couple of screws. Thus, there is no need to disturb the tubing within the upper module as in the prior art devices.
The seal subs 36 also have dual O-rings 82, but if one O-ring 82 fails, it can be repaired in place by unscrewing the male member from the lower junction plate 38 without removing the entire electronics module 30. The seal sub interface plates functionally connecting the modules have a "lost motion" float (not shown) built into the connections between the junction plate 38 and their parts, so that when the pod 10 is lifted, these connections are not loaded in tension with the weight of the pod. There are four lift points 46 for raising the pod 10, shown generally about the solenoid housings 42 in FIG. 2. The plate junction plate 38 attached to the upper electronics module 30 has slack with respect to the junction plate 38 that is attached to the lower hydraulic module 32. In this manner, when the pod is lifted, the lost motion float that is built into the junction plates 38 is going to be largely taken up. If there was no such lost motion built in, the bolts connecting the plates would be carrying the weight of the pod. Special shoulder bolts are used to provide the "loose" connections resulting in the lost motion. Again, the clear advantage in this design is that it doesn't load that junction plate 38 with the full weight of the lower module 32. The only loading on the interface bolts will result from the separating force of pressure acting at the seal subs. A similar lost motion float could also be used between the stab 34 and the pod base block 72 to relieve the load of the hydraulic cylinder 64. This leaves the stab 34 free to float against the pad base block 72.
FIGS. 11a and 11b illustrate an electrical connection that is provided through the stab 34. An electrical connector 102 that can make-or-break under water has been specially adapted for the hydraulic pod stab 34. The connector 102 permits electrical communication directly between the electronics module 30 and the BOP stack. Thus, the connection is automatically made up by the lowering of the stab 34 into the BOP receiver block 74. The male portion of the connector is fastened to a plate that's mounted on the bottom side of the BOP receiver block 74. The female portion is mounted in the lower portion of the pod stab 34. So when the stab 34 comes into the BOP receiver block 74, it automatically makes up the electrical connection. The female is designed so that when it disconnects, the sockets in the female connection are sealed off and may be pulled up so that they work subsea. The male pins are on the non-power side when disconnected.
In a preferred embodiment, there is room for two connectors on the lower surface of the stab 34. One connector, for example, is related to a "smart" BOP read-back. At the upper portion of the stab 34, there's a 90° elbow 104 fitting that has a connection on it for attachment to a female swivel hose connection. A length of hose (not shown) is designed to lay on top of the stab 34, The hose has a loop so that when the stab moves up and down, the hose is able to flex freely and is not unduly tensioned. The electrical connector on the hose end opposite the stab feeds through a bulk-head into a junction box 56 (shown in FIG. 3) above the stab 34, where it is electrically connected to the electronics module components. The junction box 56 is adapted for six electrical connectors, four on top, and two underneath. The connector seal points each have a pressure port for testing between the o-ring seals to ensure sealing integrity. A jumper assembly, which connects to junction box 56, comprises wires with soldered connections on each end with boot seals over each connection. After the connections for the jumper assembly are terminated, the hose is filled with fluid. Thus, the electrical wires inside the hose are immersed in a friendly fluid that pressure-compensates the hose with the sea. The flexible hose in effect becomes a pressure membrane to balance pressure.
FIG. 11a shows the plate that receives the mating female connector in its position, bolted to the underside of the BOP receiver block 74. Because misalignments between the male and female connectors can occur, the connectors are brought together by complementary flats 106 in the connector guide 107. As seen in FIGS. 12a, 12b and 12c, there are flats 106 in the upper connector member 108, and complementary flats 106 on the lower connector member 110. A pin 118 is included in the connector guide 107 to prevent rotation with the connector 102 and the connector guide 107. The flats 106 function by allowing movement in all directions to parallel to the stab 34 and the BOP receiver block 74 which allows the connectors line themselves up. Also, included is a wave spring 98 which is located between the upper connector member 108 and the electrical connector 102. The wave spring 98 allows some elastic movement while the electrical connector 102 is being seated.
Since the connection is made up by four pins, it won't permit relative rotation between the male and female connectors. However, the connection will handle relative movement in either of the X-Y directions. In other words, the flats 106 on one connector won't let the mating connector rotate, but will let it slide. Relative movement is permitted in two degrees of freedom, and results in automatic alignment between the parts to complete the desired electrical connection.
Although exemplary embodiments have been shown and described, those skilled in the art will recognize that other embodiments fall within the spirit and scope of the invention. Accordingly, the invention is not limited to the disclosed embodiments, but rather is defined solely by the scope of the appended claims. | A blowout preventer control system has been developed with a pod with features which include a retractable internal stab with fixed internal hydraulic connection lines to the blowout preventer. The hydraulic connection lines are connected by pressure activated packer seals. The stab also has an electrical connector to the blowout preventer which uses a guide which proper aligns the pins of the connector without any rotation. The piping of the control system uses an adjustable length type tubing to reduce the binding on the pipe. A lost motion float is used reduce the loading on the connection bolts of the system. The entire system is enclosed with plates with keep the expended hydraulic fluid in contact with the internal mechanisms. The transducers and seal subs are located for easy accessibility with no disruption of the surrounding elements of the system. | 4 |
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is the U.S. National Phase of PCT Appln. No. PCT/EP2014/060425 filed May 21, 2014, which claims priority to German Application No. 10 2013 210 039.6 filed May 29, 2013, the disclosures of which are incorporated in their entirety by reference herein.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The invention relates to a process for producing granular polysilicon.
[0004] 2. Description of the Related Art
[0005] Polycrystalline silicon granules, or polysilicon granules for short, are an alternative to the polysilicon produced in the Siemens process. Whereas the polysilicon is produced in the Siemens process as a cylindrical silicon rod, which, before further processing thereof, must be comminuted to produce what is termed chip poly in a time-consuming and costly manner and may also need to be cleaned, polysilicon granules have the properties of bulk goods and can be used directly as a raw material, e.g. for monocrystalline production for the photovoltaics and electronics industries.
[0006] Polysilicon granules are produced in a fluidized-bed reactor. This is carried out by fluidizing silicon particles by means of a gas flow in a fluidized bed, wherein the bed is heated up to high temperatures via a heater. By adding a silicon-containing reaction gas, a pyrolysis reaction proceeds on the hot particle surfaces. In this process elemental silicon is deposited on the silicon particles and the individual particles grow in diameter. Owing to the regular take-off of grown particles and addition of smaller silicon particles as seed particles (termed “seed” in the further course of the document), the process can be operated continuously with all of the advantages associated therewith. As silicon-containing reactant gases, silicon-halogen compounds (e.g. chlorosilanes or bromosilanes), monosilane (SiH 4 ), and mixtures of these gases with hydrogen are described. Such deposition methods and devices therefor are known, for example, from U.S. Pat. No. 4,786,477 A.
[0007] Silicon deposition in a fluidized-bed reactor with silanes (SiH n X 4-n where X=halogen, n=0-4) usually takes place at temperatures between 600° C. and 1200° C. Feed gas streams must be heated up, off-gas streams and the solid product (polycrystalline granules) must be cooled for cleaning and/or further processing.
[0008] Since in the production of polysilicon the production costs are becoming of increasingly greater importance, it would be desirable to save heating energy. In this respect, in the prior art, some proposals have already been made.
[0009] U.S. Pat. No. 6,827,786 B2 discloses a reactor for producing granular polysilicon, comprising a heat zone beneath the reaction zone having one or more tubes which are heated by one or more heaters, a mechanism which allows silicon granules to be pulsed to and fro between heating and reaction zones, wherein this mechanism comprises a separate inlet for introducing silicon-free gas into the heating zone, a separate inlet for introducing silicon-containing gas into the reaction zone, and a heating means for heating the silicon-free gas to a reaction temperature. It is known that heat can be recovered from the granules that are branched off by means of a heat exchanger, by heating up incoming silanes. A problem, however, is the formation of wall deposit due to the silicon-containing gas, if the wall temperature is too high. The granules, by direct contact with the silicon-containing gas, can also give off heat thereto.
[0010] US 2011212011 A1 discloses a process for producing polycrystalline silicon granules in which the off-gas heat is used for heating up seed particles by means of heat exchangers.
[0011] US 2012207662 A1 discloses a reactor for producing polycrystalline silicon (Siemens process, cylindrical silicon rods), in which heat is recovered by a coolant for reactor cooling. By using hot water having a temperature above the boiling point of the coolant and pressure reduction of the hot water, some of the hot water is withdrawn from the reactor in the form of steam and used as a source of heat for other applications.
[0012] From the problems described there resulted the objective of the invention.
SUMMARY OF THE INVENTION
[0013] The problem of heat recovery in granular polysilicon production is solved by a process for producing granular polysilicon in a fluidized-bed reactor, comprising fluidizing silicon particles by means of a fluidizing gas feed in a fluidized bed which is heated to a temperature of 600-1200° C., adding a silicon-containing reaction gas and depositing silicon on the silicon particles, forming granular polysilicon is which is then removed from the reactor, and also removing off-gas, wherein off-gas that is removed is used for heating up fluidizing gas or reaction gas, or for heating up an aqueous medium in a twin-tube o tube-bundle heat exchanger.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] FIG. 1 shows schematically how, in a fluidized-bed reactor, off-gas is used for heating up feed gas streams.
[0015] FIG. 2 shows schematically how, in a fluidized-bed reactor, off-gas is used for heating up seed particles.
[0016] FIG. 3 shows schematically how, in a fluidized-bed reactor, product granules are used for heating up fluidizing gas.
[0017] FIG. 4 shows schematically how, in a fluidized-bed reactor, off-gas is used for heating up cooling water.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0018] Preferably, as fluidizing gases, H 2 , N 2 Ar or SiCl 4 are used. The silicon-containing reaction gas is preferably a silane (SiH 4-n Cl n , n=0-4) or a mixture of silane and H 2 , N 2 , Ar or SiCl 4 .
[0019] Preferably, the aqueous medium that is heated up is used for generating electricity or steam or for heating up another medium having a temperature lower than the aqueous medium that is heated up. Preferably, the off-gas heats up a cooling water stream in a heat exchanger, which cooling water stream is then used for generating electricity or for heating up a medium having a lower temperature, or which is then evaporated.
[0020] Preferably, off-gas that is removed is used for heating up fluidizing gas or reaction gas, and for heating up a cooling water stream in a heat exchanger.
[0021] In addition, granular polysilicon that is removed is preferably used for heating up the fluidizing gas. For this purpose, most preferably, fluidizing gas flows round the granular polysilicon in a container or in a pipe, and in this process heat is released to the fluidizing gas by direct contact.
[0022] Likewise, it is preferred that the off-gas is used for heating silicon particles, wherein the heat exchange proceeds by the means that off-gas flows round the silicon particles in a container or in a pipe, and in the process the silicon particles take up heat from the off-gas direct contact.
[0023] In a preferred embodiment, the off-gas heats both the gas streams that are fed, namely fluidizing gas and reaction gas, wherein two heat exchangers are used.
[0024] As heat exchanger, a twin-tube, or a tube-bundle heat exchanger is preferred.
[0025] The heat removed from the reactor via the off-gas can be used for heating up one or more feed gas streams and in addition the seed material.
[0026] Since the off-gas stream also contains dust-form silicon which has a tendency to form wall deposits in heat exchangers, in the selection of the heat exchangers, apparatuses having large flow-cross sections are to be preferred. When reagent gas is heated up with the off-gas, twin-tube or tube-bundle heat exchangers are particularly suitable.
[0027] The off-gas heat can be utilized by the off-gas flowing through a container in which seed particles are present, as a result of which the seed particles are heated up. Instead of a container, a pipe can alternatively be used, via which both material streams are brought into direct contact and through which they especially flow in counterflow.
[0028] The invention therefore provides utilizing off-gas heat in order to heat up feed gas or generate steam. In addition, the invention provides utilizing granules for steam generation.
[0029] It has been found that utilizing the off-gas heat for heating up media or for steam generation contributes markedly more to the energy efficiency of the process than the utilization of the off-gas heat of the granules.
[0030] The invention will be described hereinafter with reference to examples and with reference to FIGS. 1-4 .
LIST OF REFERENCE SYMBOLS USED
[0000]
1 Feed gas stream 1
2 Feed gas stream 2
3 Heat exchanger 1
4 Heat exchanger 2
5 Fluidized-bed reactor
6 Reactor off-gas
7 Seed
8 Product granules
9 Cooling water
EXAMPLES
[0040] A fluidized-bed process for silicon deposition from trichlorosilane using H 2 as a secondary gas (fluidizing gas) is considered.
[0041] The deposition process takes place at a temperature of 1000° C. and a pressure of 6 bar(abs).
[0042] The material stream of H 2 is 24.66 kg/h.
[0043] A trichlorosilane/H 2 mixture having a mol fraction of 70% TCS is added as primary gas (reaction gas) at a mass stream of 875.55 kg/h. This reaction gas may be preheated to a maximum of 350° C. to avoid silicon deposits in the feed lines.
[0044] In chemical equilibrium, there results therefrom at a mass stream of 860.81 kg/h of off-gas, a net deposition rate of 33.85 kg/h of silicon, wherein 5% is lost as wall deposition in the reactor and as dust via the off-gas path, providing a net deposition rate of 32.16 kg/h of silicon. Seed particles are added to the reactor at a rate of 5 kg/h.
[0045] It is assumed that the off-gas cools from 1000° C. to 850° C. owing to diverse cooled internals and heat losses in the off-gas tube.
[0046] In the calculation of k*A values for heat exchangers, in each case the counterflow heat exchanger model is used as a basis.
Example 1
[0047] In this embodiment, which is shown schematically in FIG. 1 , the off-gas 6 heats up both gas streams 1 and 2 that are fed. For this purpose, two heat exchangers 3 and 4 are used.
[0048] The H 2 stream 1 is not subject to an upper temperature limit, for which reason, it is heated up in a first heat exchanger 3 at a relatively high temperature level.
[0049] Then, the off-gas 6 heats up the TCS/H 2 gas mixture (feed gas stream 2 ) to a temperature of approximately 350° C. by means of heat exchanger 4 .
[0050] Overall, an amount of heat of 136.9 kW can be recovered from the process.
[0051] Exact values for the heat exchangers 3 , 4 may be found in table 1 and table 2.
[0052] Table 1 shows data for heat exchanger 3 .
[0000]
TABLE 1
Inlet temperature off-gas
850.00
° C.
Outlet temperature off-gas
584.12
° C.
Inlet temperature H 2
20.00
° C.
Outlet temperature H 2
800.00
° C.
Heat transferred
78.50
kW
Delta T log
212.16
° C.
k*A heat exchanger
370.00
W/K
[0053] Table 2 shows data for heat exchanger 4 .
[0000]
TABLE 2
Inlet temperature off-gas
584.12
° C.
Outlet temperature off-gas
381.60
° C.
Inlet temperature H 2 /TCS
20.00
° C.
Outlet temperature H 2 /TCS
350.00
° C.
Heat transferred
58.37
kW
Delta T log
293.26
° C.
k*A heat exchanger
199.03
W/K
[0054] Since the off-gas 6 can also contain fine silicon dust, the heat exchangers 3 , 4 should not have geometries having excessively narrow cross sections.
[0055] For example, a twin-tube or tube-bundle heat exchanger are useful.
Example 2
[0056] In this embodiment, which is shown schematically in FIG. 2 , the off-gas 6 preheats the fed seed 7 .
[0057] Only a minimal amount of heat of 1.02 kW is necessary.
[0058] The heat can be transferred, for example, by the container with seed 7 being flushed by hot off-gas 6 .
[0059] Table 3 shows data for the heat exchanger.
[0000]
TABLE 3
Inlet temperature off-gas
850.00
° C.
Outlet temperature off-gas
846.58
° C.
Inlet temperature seed
20.00
° C.
Outlet temperature seed
835.00
° C.
Heat transferred
1.02
kW
Delta T log
202.43
° C.
k*A heat exchanger
5.04
W/K
Example 3
[0060] This example is shown schematically in FIG. 3 . It is not subject matter of the patent, but is only given for comparison with the other scenarios.
[0061] The product granules 8 having a mass stream of 37.16 kg/h (32.16 kg/h net deposition+5 kg/h of seed) heats up the H 2 feed gas stream 1 .
[0062] It is assumed that the granular silicon 8 cools from 1000° C. to 900° C. via diverse cooled internals and on the way to the heat exchanger 3 .
[0063] In the heat exchanger 3 , an amount of heat of 8.22 kW is transferred.
[0064] Similarly to example 2, the use of a product container in which preferably H 2 flows through the hot granules from the reactor is conceivable.
[0065] It is clear that, via utilization of the off-gas heat for feed preheating, an amount of energy higher by more than an order of magnitude can be recovered than via recovery of waste-heat of granules 8 .
[0066] Table 4 shows data for the heat exchanger.
[0000]
TABLE 4
Inlet temperature H 2
20.00
° C.
Outlet temperature H 2
104.65
° C.
Inlet temperature granules
900.00
° C.
Outlet temperature granules
25.00
° C.
Heat transferred
8.22
kW
Delta T log
155.91
° C.
k*A heat exchanger
52.74
W/K
Example 4
[0067] Off-gas mass stream 6 heats up a cooling water stream 9 in a heat exchanger.
[0068] This cooling water stream is at a pressure of 10 bar(abs) and is heated to 170° C. (boiling temperature: 180° C.)
[0069] The cooling water that is heated up can be used afterwards, for example, for heating up media having a low temperature level.
[0070] Likewise, in a subsequent flash evaporation of the water stream or by giving off the heat in an evaporator to a water stream having a lower pressure, steam can be generated for producing electricity.
[0071] At 211 kW, in comparison with the other examples, much heat is transferred. Therefore, this embodiment is particularly preferred.
[0072] Table 5 shows data for the heat exchanger.
[0000]
TABLE 5
Mass stream of cooling water
1075
kg/h
Inlet temperature cooling water
20.00
° C.
Outlet temperature cooling water
170.00
° C.
Inlet temperature off-gas
850.00
° C.
Outlet temperature off-gas
123.17
° C.
Heat transferred
210.51
kW
Delta T log
305.89
° C.
k*A
688.18
W/K | Production of granular polysilicon is made more economical by extracting heat from the hot off-gas from the fluidized bed reactor to heat at least one of a fluidizing gas, reactant gas, silicon feed particles, or an aqueous medium. | 2 |
FIELD OF THE INVENTION
[0001] The present invention relates generally to products that enhance personal well being. More specifically, the present invention relates to pockets with silver linings on gift items.
BACKGROUND OF THE INVENTION AND DESCRIPTION OF THE PRIOR ART
[0002] Blankets with pockets are well known in the arts. These pockets serve a variety of different purposes.
[0003] U.S. Pat. No. 5,136,738, issued to Denson, discloses a blanket that is containable in a pocket. U.S. Pat. No. 3,226,737, issued to Rote, discloses a blanket with pockets at four corners for containing weighted materials that prevent the blanket from blowing in the wind. U.S. Pat. No. 5,443,880, issued to Wike, discloses a blanket with a closable pocket for carrying or containing articles of value. U.S. Pat. No. 5,072,467, issued to Hunt, discloses a blanket with a pocket that can contain either valuable items or weighted materials. Design Patent Des. 305,844 discloses a pocket attached to the front of a bunny, which is further attached to the blanket.
[0004] Additionally, there are some blankets which form a pocket in their entirety, such as U.S. Pat. No. 3,636,566, issued to Sutherland, which discloses a blanket/pocket for containing a small child and U.S. Pat. No. 3,412,410, which discloses a blanket/pocket for containing a small child and has a further small pocket for containing a pillow for the small child.
[0005] All of these disclosures relate to pocket on blankets that serve only non-sentimental purposes. Therefore, there is a present need for a pocketed articles that satisfies sentimental voids felt by persons need.
[0006] The novel features that are considered characteristic of the invention are set forth with particularity in the appended claims. The invention itself, however, both as to its structure and its operation together with the additional objects and advantages thereof will best be understood from the following description of the preferred embodiment of the present invention. Unless specifically noted, it is intended that the words and phrases in the specification and claims be given the ordinary and accustomed meaning to those of ordinary skill in the applicable art or arts. If any other meaning is intended, the specification will specifically state that a special meaning is being applied to a word or phrase. Likewise, the use of the words “function” or “means” in the Description of Preferred Embodiments of the invention is not intended to indicate a desire to invoke the special provision of 35 U.S.C. §112, paragraph 6 to define the invention. To the contrary, if the provisions of 35 U.S.C. § 112, paragraph 6, are sought to be invoked to define the invention(s), the claims will specifically state the phrases “means for” or “step for” and a function, without also reciting in such phrases any structure, material, or act in support of the function. Even when the claims recite a “means for” or “step for” performing a function, if they also recite any structure, material or acts in support of that means of step, then the intention is not to invoke the provisions of 35 U.S.C. §112, paragraph 6. Moreover, even if the provisions of 35 U.S.C. § 112, paragraph 6, are invoked to define the inventions, it is intended that the inventions not be limited only to the specific structure, material or acts that are described in the preferred embodiments, but in addition, include any and all structures, materials or acts that perform the claimed function, along with any and all known or later-developed equivalent structures, materials or acts for performing the claimed function.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] FIG. 1 illustrates a typical article, such as a blanket, that has a pocket with a silver lining.
[0008] FIG. 2 is close-up of the pocket of FIG. 1 .
[0009] FIG. 3 illustrates one embodiment of a silver lined pocket according to the present invention.
[0010] FIG. 4 illustrates an alternate embodiment of the silver lined pocket according to the present invention.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0011] The present invention is a personal article 10 , such as a blanket, backpack, pouch, purse, and the like, that comprises a body element 15 and a pocket element 20 attached to the body element 15 . Critical to the present invention is the lining of the pocket element 20 . In the present invention, the pocket element 20 must have a silver lining 25 . The silver lining 25 of the present invention may either be actual silver metal, a weave of silver threads ore merely silver colored materials, such as fabric.
[0012] The silver lining 25 of the present invention serves to file a void felt by persons in need by indicating that a bad situation encountered by the person in need is temporary and a better future is imminent. This then raises the spirits of the person in need giving them hope and potentially helping in any healing process.
[0013] In one embodiment of the present invention, FIG. 3 , the pocket 20 has a silver lining 25 on one side of the pocket. In another embodiment of the present invention, FIG. 4 , the pocket 20 has a silver lining 25 on both sides of the pocket.
[0014] In the preferred embodiment of the present invention, the silver lined pocket contains a gift item or card for the recipient of the personal article.
[0015] The preferred embodiment of the invention is described above in the Description of Preferred Embodiments. While these descriptions directly describe the above embodiments, it is understood that those skilled in the art may conceive modifications and/or variations to the specific embodiments shown and described herein. Any such modifications or variations that fall within the purview of this description are intended to be included therein as well. Unless specifically noted, it is the intention of the inventors that the words and phrases in the specification and claims be given the ordinary and accustomed meanings to those of ordinary skill in the applicable art(s). The foregoing description of a preferred embodiment and best mode of the invention known to the applicant at the time of filing the application has been presented and is intended for the purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise form disclosed, and many modifications and variations are possible in the light of the above teachings. The embodiment was chosen and described in order to best explain the principles of the invention and its practical application and to enable others skilled in the art to best utilize the invention in various embodiments and with various modifications as are suited to the particular use contemplated. | A product comprising a body with a pocket attached to the body, wherein the improvement is a silver lining in the pocket. | 0 |
TECHNICAL FIELD
[0001] The present invention relates to a brake controller for an accelerometer based towed vehicle braking system and a method of operating the brake controller.
BACKGROUND OF INVENTION
[0002] Towed vehicles such as trailers of various classes have different braking systems. Commonly, trailers with weights between 750 kg and 3.5 tons have electromagnetic braking systems or hydraulic braking systems controlled by electromagnetic actuators. For both of these systems the braking force in the trailer is controlled by an electrical signal from the towing vehicle.
[0003] Historically, the level of trailer braking was controlled by a simple manual adjustment of output level. More recently, trailer braking systems exist that attempt to provide a simpler user experience by providing trailer braking proportional to towing vehicle braking. One common way to implement this is to use an accelerometer or pendulum to measure vehicle braking force and to apply proportional force with the trailer brakes. Known products using an accelerometer to measure vehicle braking force have been required to be installed in a particular orientation to allow braking force to be measured along a single axis.
[0004] However a difficulty may arise because the accelerometer may measure not only the braking deceleration, but also artefacts. Artefacts that may be measured include i) noise from road; ii) gravity, adjusted by pitch and roll of the vehicle; iii) centripetal acceleration; and iv) acceleration due to pitch and roll, assuming that the accelerometer is not placed at the centroid of the vehicle. Designs for brake controllers exist that compensate for (ii) by eliminating components not in the horizontal plane. However, such systems are sensitive to lateral acceleration of the vehicle since they do not compensate for (ii) or for horizontal components of (i) or (iv). Existing systems that measure only forward acceleration require mounting at a specific angle to the vehicle axes.
[0005] The present invention may provide a brake controller for a towed vehicle braking system and a method for operating the brake controller. The controller and method may include an acceleration model to minimise the above mentioned artefacts and/or to provide more optimal calculation of deceleration. The controller and method may include one or more feedback algorithms for measurement, calibration and/or validation of direction and consequent calculation of deceleration/braking force in a forward direction.
[0006] The controller and method may also include one or more algorithms for automating generation of parameters for the acceleration model.
[0007] A reference herein to a patent document or other matter which is given as prior art is not to be taken as an admission that that document or matter was known or that the information it contains was part of the common general knowledge in Australia or elsewhere as at the priority date of any of the disclosure or claims herein. Such discussion of prior art in this specification is included to explain the context of the present invention in terms of the inventor's knowledge and experience.
[0008] Throughout the description and claims of this specification the words “comprise” or “include” and variations of those words, such as “comprises”, “includes” and “comprising” or “including, are not intended to exclude other additives, components, integers or steps.
SUMMARY OF INVENTION
[0009] According to one aspect of the present invention there is provided a brake controller for a towed vehicle braking system, said controller being adapted to be mounted in a towing or a towed vehicle having a longitudinal axis for generating a braking control signal to said towed vehicle braking system, said controller comprising: an inertial sensor including plural sensor axes adapted to be mounted in an undefined orientation relative to said longitudinal axis for generating sensor data associated with each sensor axis; a memory device for storing said sensor data associated with each sensor axis; and a processor for processing said sensor data with said braking control signal to evaluate said orientation of said inertial sensor relative to said longitudinal axis; whereby said brake controller is adapted to control activation of said towed vehicle braking system in a manner that is relatively insensitive to acceleration of said vehicle in a lateral direction and to said orientation of said inertial sensor without prescribing a mounting orientation of said brake controller relative to said towing or towed vehicle.
[0010] The brake controller may include additional circuitry for control and measurement of braking systems and/or vehicle status.
[0011] The processor may be adapted to perform feedback calibration on the sensor data to facilitate determining a forward direction vector of said vehicle in a frame of reference of said inertial sensor and/or to reduce effects of said acceleration of said vehicle in said lateral direction. The calibration may include single shot calibration, continuous calibration or continuous checking of calibration to facilitate determining a forward direction vector of said vehicle in a frame of reference of said inertial sensor and/or to reduce effects of said acceleration of said vehicle in said lateral direction. The processor may perform cross-correlation of the sensor data with the braking control signal and/or a brake light signal such that a direction of maximum correlation is used as an estimate of the longitudinal axis. The cross correlation may be performed using vector mathematics and/or a filtering process may be followed by filtering in an angular or vector domain. In some embodiments the cross-correlation may be performed using filtering in an angular or vector domain. The towed vehicle may include a trailer. The inertial sensor may include a multi-axis accelerometer. The multi-axis accelerometer may be adapted to sense braking forces on the towed and towing vehicles. The brake controller may be mounted in the towing or towed vehicle.
[0012] According to a further aspect of the present invention there is provided a method of operating a brake controller for a towed vehicle braking system, wherein said controller is adapted to be mounted in a towing or a towed vehicle having a longitudinal axis for generating a braking control signal to said towed vehicle braking system, said method comprising: mounting an inertial sensor including plural sensor axes in an undefined orientation relative to said longitudinal axis for generating sensor data associated with each sensor axis; storing said sensor data associated with each sensor axis in a memory device; and processing said sensor data with said braking control signal to evaluate said orientation of said inertial sensor relative to said longitudinal axis; whereby said brake controller is adapted to control activation of said towed vehicle braking system in a manner that is relatively insensitive to acceleration of said vehicle in a lateral direction and to said orientation of said inertial sensor without prescribing a mounting orientation of said brake controller relative to said towing or towed vehicle.
BRIEF DESCRIPTION OF DRAWINGS
[0013] A preferred embodiment of the present invention will now be described with reference to the accompanying drawings wherein:
[0014] FIG. 1 shows a trailer braking system including a vehicle mounted brake controller;
[0015] FIG. 2 shows a braking system and brake controller with a calibration algorithm for calculating a desired value of acceleration;
[0016] FIG. 3 shows a braking system and brake controller with an algorithm for feedback chain calibration; and
[0017] FIG. 4 shows a braking system and brake controller with an algorithm for performing on-line calibration.
DETAILED DESCRIPTION
[0018] FIG. 1 shows a trailer braking system including a brake controller 10 mounted in a towing vehicle (not shown) with wires leading back to a towed vehicle such as a trailer 11 . Controller 10 is associated with a remote head 12 for providing potentiometer based gain control, a pushbutton for status control and one or more LEDs for displaying status of the braking system. Brake controller 10 is adapted to operate trailer brakes 13 based on sensed deceleration of the towing vehicle. Brake controller 10 includes a multi-axis inertial sensor/accelerometer 14 for sensing deceleration to the towing vehicle along a plurality of directional axes. Brake controller 10 includes an input 15 from the towing vehicle brake light circuit for determining when the vehicle brakes are applied.
[0019] Brake controller 10 includes a microprocessor or microcontroller 16 that is responsive to the sensed deceleration to supply power to trailer brakes 13 that may be a function of the sensed deceleration. Microcontroller 16 is adapted to execute one or more algorithms stored in an associated memory such as RAM and/or ROM 17 to facilitate measurement and/or validation of direction and/or calculation of acceleration and/or braking force in a forward or towing direction.
[0020] Known controllers of this type need to be compensated for artefacts as discussed above. The known controllers also have been required to be installed in a predetermined orientation to allow braking force to be measured along a single axis or alternatively have needed to be manually compensated for mounting orientation relative to the towing vehicle, or alternatively may have an increased sensitivity to lateral acceleration.
[0021] Described below are an acceleration model and algorithms that may facilitate measurement and/or validation of direction and/or consequent calculation of deceleration and braking force in a forward direction to reduce or remove effects of lateral acceleration and/or other artefacts of a measurement process.
Acceleration Model
[0022] In the following discussion, there may be three different reference frames with different basis vectors. In an external reference frame three directions may be denoted, namely X ext ={{right arrow over (x)} ext , {right arrow over (y)} ext , {right arrow over (z)} ext }.
[0023] In the towing vehicle's reference frame, three directions may be denoted, namely) X car ={{right arrow over (x)} car , {right arrow over (y)} car , {right arrow over (z)} car }.
[0024] In an accelerometer reference frame, the basis may be denoted as X acc ={{right arrow over (x)}, {right arrow over (y)}, {right arrow over (z)}}. Conversion between the reference frames may be performed by rotation matrices Q car : X ext →X car and Q acc : X car →X acc . In the following discussion, it is assumed that Q car may vary with time, and that Q acc is fixed but unknown.
[0025] Measurement from the accelerometer may be modelled as:
[0000] {right arrow over (a)} total ={right arrow over (a)} f +{right arrow over (g)}+{right arrow over (a)} c +{right arrow over (a)} l +{right arrow over (n)}+{right arrow over (o)} (1)
[0000] wherein:
{right arrow over (a)} f =A desired . {right arrow over (x)} car denotes acceleration due to braking or acceleration of a vehicle/trailer system and A desired denotes desired input to a braking control. During normal braking A desired may be expected to lie in the range 0≦A desired
[0000]
≤
4.5
m
s
2
;
[0000] {right arrow over (g)} denotes acceleration due to gravity and is approximately equal to 9.81
[0000]
m
s
2
·
z
→
ext
≈
9.81
m
s
2
·
z
→
car
;
[0000] {right arrow over (a)} c denotes centripetal acceleration of the vehicle and is equal to
[0000]
v
2
r
·
y
→
car
.
[0000] Based on a sample of curves including radius r equal to 10 m and velocity v equal to
[0000]
2
m
s
[0000] for a slow suburban corner, and radius r equal to 200 m and velocity v equal to
[0000]
30
m
s
[0000] for a wide rural curve, {right arrow over (a)} c may be expected to lie in the range
[0000]
0
≤
a
→
c
≤
4.5
m
s
2
;
[0000] {right arrow over (a)} l denotes acceleration due to changes in roll and pitch of the vehicle and uneven road surface. It may be in any direction, depending on the kind of movement and the location of the accelerometer relative to the towing vehicle. This may be expected to include transients with ∥{right arrow over (a)} l |>>∥{right arrow over (g)}∥. Duration of transients may be expected to be less than 200 ms. This may be expected to increase with speed. Some transients may also occur due to engine noise, passenger movement and/or driver movement. Acceleration {right arrow over (a)} c will likely have zero mean over periods of less than 1 second;
{right arrow over (n)} denotes measurement noise of the accelerometer. This is expected to be independently Gaussian distributed in each axis with a Brownian spectrum. The level of the noise is generally also specified in the data-sheet for the accelerometer; and
{right arrow over (o)} denotes offset of the accelerometer. This may generally be non-zero and is composed of two main contributions, namely: raw offset, which may be relatively constant in X acc and gain non-linearity and cross-axis sensitivity acting on gravity, which may vary with Q car .
[0026] FIG. 2 shows a braking system and brake controller with a calibration algorithm for calculating the aforesaid desired value of acceleration (A desired ) from a combined acceleration signal ({right arrow over (a)} total ). The calibration algorithm may derive a scalar value A desired from the aforesaid measurement {right arrow over (a)} total . The calibration algorithm may include two steps as described below, namely offset component removal and scalar conversion.
Offset Component Removal
[0027] The first step is to remove accelerator offset components including components which relate to x-axis sensitivity to gravity. Since {right arrow over (a)} c , {right arrow over (a)} l , and {right arrow over (n)} are zero-mean processes with relatively high bandwidths, a local average {right arrow over (μ)} local of measured acceleration ({right arrow over (a)} total ) may be a good estimator of {right arrow over (g)}+{right arrow over (o)} if Q car is constant over the averaging period, so that {right arrow over (g)}+{right arrow over (o)}−{right arrow over (μ)} local ≈{right arrow over (0)}.
[0028] In many circumstances, this assumption can be made for on-road travel and a high pass filter may be applied with cut-off above the bandwidth of {right arrow over (a)} c , {right arrow over (a)} 1 , and {right arrow over (n)}, but below the bandwidth of the transformation matrix Q car , to reduce or remove the offset components.
[0029] However, this has a potential to cause problems such as drift when a constant level of braking is applied, due to a component of braking acceleration falling outside of the bandwidth of the high pass filter. To avoid or at least minimize this problem a high pass filter may be implemented as shown in FIG. 2 .
[0030] Measured acceleration may be continuously averaged to estimate local average {right arrow over (μ)} local , and then frozen at the start of braking to prevent drift due to direct current (DC) component of braking. The steps of the process are described below.
[0031] Referring to FIG. 2 , total acceleration 20 consists of a summation of Trailer+vehicle Brakes block 21 , which corresponds to acceleration {right arrow over (a)} f in equation (1), plus impairments block 22 which includes non-braking components of acceleration in equation (1). Total acceleration 20 is measured by the accelerometer in acceleration measurement block 23 .
[0032] The output of acceleration measurement block 23 ({right arrow over (a)} total ) is filtered with low-pass filter 24 to provide an estimate {right arrow over (μ)} local , of {right arrow over (g)}+{right arrow over (o)}. The bandwidth of low-pass filter 24 is less than 1 Hz to reject short-term variations in Q car due to change in road camber and/or slope.
[0033] The filtered acceleration is then gated at gate 25 via brake light signal 26 . When there is no brake light signal 26 {right arrow over (μ)} local is allowed to vary. When brake light signal 26 is asserted, then low pass filter 24 continues to operate, but its output will be discarded at gate 25 . Only the last estimate of {right arrow over (μ)} local from before the brake lights were asserted is used. Subtracting the last estimate of {right arrow over (μ)} local provides low pass filtered data in acceleration before braking block 27 .
[0034] The low-pass filtered data from block ({right arrow over (μ)} local ) is then subtracted from the output of acceleration measurement block 23 to form an implicit high-pass filter. The output of this implicit high-pass filter provides an unbiased estimate 28 of {right arrow over (a)} total with biases or constant offset components removed.
[0035] The offset removal step produces a vector output {right arrow over (a)} total -{right arrow over (μ)} local , and is followed by a scalar conversion step which may produce a scalar estimate of acceleration  desired .
Scalar Conversion
[0036] In order to estimate a forward component of the acceleration common, Euclidean vector projection using the Euclidean inner product (also known as dot product) may be used to estimate A desired as follows:
[0000] Â desired ={right arrow over (x)} car ·( {right arrow over (a)} total −{right arrow over (μ)} local ) (2)
[0000] wherein the operatorS is the Euclidean inner product and ∥{right arrow over (x)} car ∥=1.
[0037] Substituting in equation (1), with its associated definitions, we have:
[0000]
A
^
desired
=
x
→
car
·
(
A
desired
·
x
→
car
+
v
2
r
·
y
→
car
)
+
x
→
car
·
(
a
→
l
+
n
→
)
+
x
→
car
·
(
g
→
+
o
→
-
μ
→
local
)
(
3
)
[0038] Since X car is orthonormal, we know that {right arrow over (x)} car ·{right arrow over (x)} car −1, {right arrow over (x)} car ·{right arrow over (y)} car =0 and {right arrow over (x)} car ·{right arrow over (y)} car =0, so that the centripetal acceleration is eliminated.
[0000] Â desired =A desired +{right arrow over (x)} car ·( {right arrow over (a)} l +{right arrow over (n)} )+ {right arrow over (x)} car ·( {right arrow over (g)}+{right arrow over (o)}−{right arrow over (μ)} local )≈ A desired +{right arrow over (x)} car ·( {right arrow over (a)} l +{right arrow over (n)} ) (4)
[0039] In addition and assuming that and if are isotropic, the RMS magnitude of {right arrow over (x)} car ·({right arrow over (a)} l +{right arrow over (n)}) will be reduced by a factor of √{square root over (3)} from ∥{right arrow over (a)} l +{right arrow over (n)}∥ due to reduction in dimension. Based on empirical vibration profiles (e.g. as specified in MIL-STD 810G Table 514.6C-VI), the assumption of isotropic vibration is likely to be a worst-case assumption.
Algorithm for Calculating Calibration Coefficients
[0040] In order to perform calculations for estimating A desired from a measurement of {right arrow over (a)} total ) the following values are required:
[0000] Offset vector: {right arrow over (μ)} local
Direction vector: {right arrow over (x)} car
[0041] Since all estimation data is acquired in the X acc basis, with Q car and Q acc unknown, the algorithm for acquiring offset and direction vectors may also operate in this basis.
[0042] The algorithm for measuring offset vector {right arrow over (μ)} local may comprise a simple low-pass filter as shown in FIG. 2 .
[0043] Two algorithms for measuring {right arrow over (x)} car are suggested below. The algorithms have in common that they rely on feedback from a brake output and/or a brake light input to accelerometer measurement. They are also able to determine if a calibrated direction is valid in the presence of impairments during calibration, as given in equation (1).
[0044] The algorithms differ in the signal that they generate and the method used to calculate direction from feedback. The first algorithm is suitable for single shot calibration and is described below under the heading FEEDBACK CALIBRATION WITH SPECIAL SIGNAL.
[0045] The second algorithm may be suitable for continuous calibration or checking of calibration and is described below under the heading FEEDBACK CALIBRATION USING NORMAL BRAKING SIGNALS.
[0000] Feedback Calibration with Special Signal
[0046] Based on equation (1), the only component of the measured signal that depends significantly on the output signal is {right arrow over (a)} f A desired ·{right arrow over (x)} car . Therefore, a good estimate {right arrow over (x)} car may be obtained by correlating the measured signal with the input signal.
[0047] However, since the braking force is always greater than 0, the braking acceleration always has a non-zero mean, and may be confused with other non-zero mean signals such as {right arrow over (g)} and {right arrow over (o)}. Therefore the DC component of the correlation should be ignored. This may be implemented by superimposing a zero-mean test or reference signal on a DC braking component and then correlating the feedback with the test or reference signal. The zero-mean signal will ensure that the DC component of the measurement is removed during the correlation process.
[0048] Any zero-mean test or reference signal may be used for this purpose but a higher computational efficiency may be achieved by using an offset sinusoidal signal. A signal processing flow chart for this is shown in FIG. 3 . In FIG. 3 , a sinusoidal signal is generated as the real part of the output of complex-valued numerically controlled oscillator (NCO) 30 . NCO 30 may be implemented via a numerically simple operation,
[0000]
A
NCO
∏
i
=
0
t
t
0
j
2
π
f
f
s
=
A
NCO
j
2
π
ft
,
[0000] with the accumulator normalised to a magnitude of 1 at intervals in order to remove cumulative quantisation error.
[0049] A DC offset component 31 may be added to the output of NCO 30 to ensure that the braking signal 32 is non-negative (i.e. ∥DC∥≧A NCO ) so that no zero-crossings in the braking signal 32 are sent to Trailer Brakes 33 .
[0050] As described above with reference to FIG. 2 , total acceleration ({right arrow over (a)} total ) is measured by the accelerometer in acceleration measurement block 23 (refer equation (1)). For numerical stability, the signal is then high-pass filtered to remove the gravity component (which is much larger than the feedback signal component) as described with reference to FIG. 2 .
[0051] The filtered real vector measurement 34 is then multiplied in complex mixer stage 35 with the conjugate of the complex scalar output of NCO 30 . The output of complex mixer stage 35 is accumulated in accumulator block 36 until it passes a confidence threshold provided via confidence algorithm block 37 . This output of confidence algorithm block 37 is then converted to a usable Forward Direction Vector in block 38 .
[0052] The trailer brakes are assumed to be a linear time invariant (LTI) system. Basic physical analysis (not presented here) suggests that this may be a suitable first-order approximation.
[0053] As in FIG. 2 , Impairments block 22 comprises non-braking components of acceleration in equation (1). Low pass filter 24 also has the same implementation and function as in FIG. 2 .
[0054] Complex mixer stage 35 combined with accumulator block 36 remove the effect of LTI group delays (e.g. introduced by springs in the towing vehicle), by converting to a phase offset as shown in equation (5) below.
[0000] e j2πft · e j2πf(t-t 0 ) = e j2πft ·e −j2πf(t-t 0 ) =e j2πft 0 (5)
[0055] Accumulator block 36 sums the output of complex mixer stage 35 to obtain an estimate:
[0000]
estimate
→
(
t
)
=
∑
i
=
0
t
t
0
acceleration
l
→
·
-
·
2
π
f
·
t
(
6
)
[0056] A threshold based on noise level may be used to determine when calibration is complete. Assuming a measurement noise distribution independent of time and an LTI braking system, then by using the Central Limit theorem it may be shown that the statistical distribution of this estimation will converge to:
[0000]
estimate
→
(
t
)
=
∼
(
t
t
0
G
F
→
,
t
t
0
σ
0
2
)
(
7
)
[0000] wherein:
({right arrow over (μ)}, σ 2 ) is a multivariate complex Gaussian distribution with mean {right arrow over (μ)} and uniform variance {right arrow over (μ)};
[0000]
t
t
0
[0000] is the number or samples cumulated. Note that the coefficient
[0000]
t
t
0
[0000] is not an exact value, but a reasonable estimate of the coefficient of σ 2 , estimated using an assumption of white noise.
σ 0 is the root-mean-square (RMS) noise;
G is a complex gain factor due to time delays (converted to a complex phase per equation (4)), trailer gain and the level of the output; and
{right arrow over (F)} is the forward direction vector.
[0057] Confidence Algorithm block 37 may then determine when accumulator block 36 has reached a desired accuracy based on the comparison
[0000]
estimate
→
(
t
)
2
>
(
3
σ
^
)
2
tan
2
(
θ
limit
)
·
n
samples
,
(
8
)
[0000] wherein {circumflex over (σ)} is the estimated signal variance, which is calculated from a sample set prior to calibration or from a pre-calculated value based on worst-case road noise, and θ limit is the target angular accuracy of the calculation.
[0058] The final step is processed in Forward Direction Vector block 38 to remove phase offset from accumulator 36 and to convert to a real vector. This real vector is the estimate of {right arrow over (x)} car as required by equation (2) for calibration.
Feedback Calibration Using Normal Braking Signals
[0059] As noted above, the DC offset of normal braking signals may be difficult to distinguish from other DC offsets (e.g. gravity, accelerometer offset). This means that calibration based on normal braking as described above may be difficult to realize in practice. To address this problem an on-line calibration algorithm may be used to perform measurements on normal braking. The on-line calibration algorithm may use a measure of change of braking at the start of a braking period to generate a single braking direction estimate per braking event. Such a measure may effectively be a single estimate of cross correlation between a brake control signal and deceleration of the vehicle. The on-line calibration algorithm may use a statistical analysis algorithm to combine the estimates to provide a more accurate estimate or to provide a measure of confidence in the estimates.
On-Line Calibration Algorithm
[0060] FIG. 4 shows a braking system and brake controller with an algorithm for performing on-line calibration.
[0061] Normal Braking Algorithm block 40 is a placeholder for the algorithm used to control the Trailer+vehicle brakes block 21 . Normal Braking Algorithm block 40 may include a fall-back timed algorithm if no direction calibration is available or a normal inertial feedback algorithm if this calibration algorithm is being used as a check.
[0062] Trailer+vehicle Brakes block 21 , Impairments block 22 and Acceleration Measurement block 23 blocks are similar to corresponding numbered blocks described with reference to FIG. 2 .
[0063] Low pass filter 41 may have a bandwidth between 1 Hz and 5 Hz. This bandwidth is higher than low pass filter 24 for {right arrow over (μ)} local to reduce filter delay and provide a faster estimate of change in acceleration.
[0064] A delay gate may be used to select direction samples for on-line calibration. Switch 42 may be controlled by brake light input 43 . The output of low pass filter 41 is normally stored in acceleration before braking block 43 , but immediately after braking, the output will be discarded for a time t delay +t phase , wherein t delay is a worst-case expected delay on the trailer brakes (approximately 0.5 s for slack in couplings and suspension) and t phase is the group delay of low pass filter block 41 . After this time, one sample of filter output will be stored in acceleration at start of braking block 44 . Further samples will be discarded until the end of braking. The difference between blocks 43 and 44 may provide a sample of acceleration in the direction of braking. The low pass filter after the delay gate may also be implemented as a discrete-time integrator (summation).
[0065] A one dimensional weighted histogram of acceleration may be generated and used to determine azimuth. Vector basis block 45 represents a 2-D vector basis embedded in X acc . It may be derived by starting with an estimate of gravity direction vector {circumflex over ({right arrow over (Z)} ext , generated in gravity estimate block 46 from a long term average of the accelerometer output. The two basis vectors are both orthogonal to {circumflex over ({right arrow over (Z)} ext and may be generated using a Gram-Schmidt process.
[0066] The output of vector basis block 45 is subjected to a convert to angle operation in block 47 . Convert to angle block 47 may include a simple atan2 operation on the measurement, projected into the 2-D vector basis. For small microcontrollers that may be used in these applications, the algorithms presented in X. Girones, C. Julia, and D. Puig, “Full quadrant approximation for the arctangent function,” IEEE Signal Processing Magazine, vol. 30, no. 1, pp. 130-135, January 2013 may be suitable.
[0067] The output of convert to angle block 47 is subjected to a binning step in block 48 . The “binning” step may consist of adding a score based on magnitude of the acceleration measurement to a histogram bin corresponding to the calculated angle of the vector. Due to a possibility of braking in reverse, the bins may be wrapped on a half-interval [0, π) instead of over the whole angular range.
[0068] The output of binning block 48 is subjected to confidence algorithm block 49 . Confidence algorithm block 49 may determine when the angular measurement is suitable for use, This may be based on peak bin (interpolated), compared with mean bin.
[0069] The output of confidence algorithm step 49 is subjected to Forward Direction Vector block 50 . Forward Direction Vector block 50 may convert angle estimation to a vector estimating {right arrow over (x)} car X acc by converting from the test vector basis to X acc .
[0070] As an alternative to the operations of [00064] to [00068], a modified Kalman filter may be used to determine a forward direction vector as follows, Input to the filter may be the difference vectors of [00063] normalised as follows:
[0000]
Δ
a
^
meas
=
Δ
a
^
meas
Δ
a
^
meas
[0000] Braking measurements taken while the vehicle is braking may by comparison with the Kalman state estimate be as follows:
[0000]
Δ
a
^
in
=
{
Δ
a
^
meas
if
Δ
a
^
meas
-
k
→
≤
Δ
a
^
meas
+
k
→
-
Δ
a
^
meas
if
Δ
a
^
meas
-
k
→
>
Δ
a
^
meas
+
k
→
[0000] The sample covariance input may be calculated as inversely proportional to the magnitude of the measurement ∥Δ{right arrow over (a)} meas ∥. The Kalman filter may be calculated according its normal definitions (refer R. E. Kalman, “A New Approach to Linear Filtering and Prediction Problems”, Transactions of the ASME—Journal of Basic Engineering, vol 82, series D, pp. 35-45, 1960) except that for ease of implementation the state estimate and state covariance estimate may be forced to be fully diagonal and the state estimate may be normalized to a vector magnitude of 1 after each step and the estimated state covariance corrected by the same factor. The estimated state vector output may be an estimate of the forward direction vector, and the state covariance may be an estimate of the accuracy of the forward direction vector. The process covariance input may be decreased to allow more accurate estimation, or increased to allow rapid convergence of the filter when the unit may have been moved.
[0071] Finally, it is to be understood that various alterations, modifications and/or additions may be introduced into the constructions and arrangements of parts previously described without departing from the spirit or ambit of the invention. | A brake controller is disclosed for a towed vehicle braking system. The controller is adapted to be mounted in a towing or a towed vehicle having a longitudinal axis for generating a braking control signal to the towed vehicle braking system. The controller comprises an inertial sensor including plural sensor axes adapted to be mounted in an undefined orientation relative to the longitudinal axis for generating sensor data associated with each sensor axis. The controller also comprises a memory device for storing the sensor data associated with each sensor axis and a processor for processing the sensor data with the braking control signal to evaluate orientation of the inertial sensor relative to the longitudinal axis. In particular the brake controller is adapted to control activation of the towed vehicle braking system in a manner that is relatively insensitive to acceleration of the vehicle in a lateral direction and to orientation of the inertial sensor without prescribing a mounting orientation of the brake controller relative to the towing or towed vehicle. A method of operating a brake controller for a towed vehicle braking system is also disclosed. | 1 |
FIELD OF THE INVENTION
The present invention relates to a method keeping clean a nozzle mouthpiece of a nozzle of a spray moistening device of a rotary printing press; the and to a device for executing the method.
DESCRIPTION OF THE PRIOR ART
A spray moistening device with spray nozzles, which are arranged next to each other in the axial direction on a so-called spray beam for moistening a printing cylinder of an offset rotary printing press, is known from U.S. Pat. No. 4,044,647.
U.S. Pat. No. 4,241,656 discloses a self-cleaning nozzle of a spray moistening device for a rotary printing press. Here, a moistening agent is swirled with air after exiting from a nozzle mouthpiece.
EP 0 126 536 A2 describes a pushbutton for a ink jet printer. The ink reservoir, the nozzle plate and nozzle bores arranged therein are cleaned by means of ultrasound excitation. The ultrasound excitation is activated during the cleaning operation.
DE 31 08 541 A1 discloses a device for generating a moistening agent fog for a moistening device of an offset printing press, using an ultrasound atomizer.
SUMMARY OF THE INVENTION
It is the object of the present invention to provide a method for keeping the nozzle mouthpieces of a spray moistening device clean, as well as an associated device, by means of which it is possible to perform preventive maintenance on spray nozzles of a spray moistening device without having to remove them.
This object is attained in accordance with the present invention by periodically activating the moistening agent that is supplied to the nozzle mouthpieces of the spray moistening device by the use of ultrasound upstream of, or in the nozzle mouthpieces. An ultrasound vibration transmitter is in communication with the fluid either in an upstream fluid chamber, or at the nozzle mouthpiece;
The advantages which can be achieved by means of the present invention lie, in particular, in that the fluid conducted through the nozzles can be activated by means of ultrasound because of the arrangement of a moistening agent, which in the operational state, is not activated by ultrasound during a spraying process and is charged with pressure, or respectively by an ultrasound vibration transmitter, which can be switched on during a cleaning process. When the fluid activated by ultrasound exits through the nozzles, the paper and ink particles on the nozzle outlet opening, or respectively on the nozzle mouthpiece, are removed.
In this way, it is easily possible to perform preventive cleaning of the spray nozzles without having to remove the nozzles. A long, trouble-free operation of the moistening device is made possible by the present invention.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention is represented in the drawings by two preferred embodiments and will be described in more detail in what follows. Shown are in:
FIG. 1, a cross section through the schematic representation of a spray nozzle unit with a device; in accordance with a first preferred embodiments of the present invention; and
FIG. 2, a detailed representation of a spray nozzle with a device in a second preferred embodiment of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
A nozzle unit 1 of a spray moistening device for moistening objects, such as, in particular a rotatable moistening distribution roller, consists of a nozzle housing 2, which is fastened by means of fastening elements, for example screws, on a first sheet metal plate 4 of a vibration-damping plate generally at 6. The vibration-damping plate 6 is arranged by means of screws on a crosspiece 9 of a nozzle beam. crosspiece 9 receives a plurality of nozzle units 1 arranged at a distance next to each other.
The nozzle housing 2 has a chamber 11, which extends in the interior of nozzle housing 2 in the horizontal direction, for example, and which is bordered on one side by a nozzle mouthpiece 13, held in place by a union nut 12, and a nozzle 14 fastened thereon. On its side opposite the nozzle mouthpiece 13, the chamber 11 is bordered by a coil holder 16, that is screwed to the nozzle housing 2, and which supports or holds a magnetic coil 17. A valve rocker 19 is arranged in the interior of the magnetic coil 17 valve rocker 19 has, at its end facing the nozzle mouthpiece 13, a sealing element 21 for closing an outlet bore 22 located in the nozzle mouthpiece 13. The magnetic coil 17 is provided with a connecting cable 20. During the operation of the magnetic coil 17, the valve rocker 19 can be moved back and forth in the horizontal direction A, so that the bore 22 located in the nozzle mouthpiece 13 will be opened and closed by means of the sealing element 21. The valve rocker 19 is sealed against the chamber 11 at the end of the magnetic coil 17 by means of a sealing ring 10.
The nozzle housing 2 has a supply bore 24, for example on its upper side, which is connected with the chamber 11 and, via a valve 26, with a pressurized water inlet 27. Opposite the bore 24 for the water inlet 27, the nozzle housing 2 is provided with a fastening connector 28, which is also connected with the chamber 11. The fastening connector 28 receives, in its axial direction, a profiled, pipe-shaped intermediate piece 29, which is made of a vibration-damping material and on whose end is fastened a known ultrasound vibration generator 31. The ultrasound vibration generator 31 is provided with a cable 30 extending to a controls means 35. A sealing ring 25 is arranged between the intermediate piece 29 and the nozzle housing 2.
The ultrasound vibration generator 31 can be embodied as a piezo-mechanical ultrasound vibration generator with a generated frequency between 20 and 30 kHz, which has a plurality, for example four, ceramic rings 33 arranged one behind the other on a rod-shaped vibration transmitter 32. An interior end 34 of the rod-shaped vibration transmitter 32, which points in the direction toward the chamber 11 and protrudes out of the ultrasound vibration generator 31, extends at least as far as into the chamber 11, as seen in FIG. 1.
The following procedure is followed in the course of cleaning the nozzle insert 14, or respectively the nozzle mouthpiece 13: the sealing element 21, which is located on the valve rocker 19, is fixed in place at a distance from the outlet bore 22 of the nozzle mouthpiece 13 in such a way that when the valve 26 is open a pressurized fluid 39, for example water, can exit through the chamber 11, the outlet bore 22 as well as the bore in the nozzle insert 14 at a spraying pressure of 3.5 bar, for example. The water inside the chamber 11 is activated by ultrasound by switching on the ultrasound vibration generator 31 through the control means 35. In the process, the water is alternatingly placed in a traction phase and an overpressure phase by means of the vibration transmitter 32 protruding into the chamber 11 with its vibration-transmitting end 34. When the water exits the nozzle insert 14, the shock waves being generated in the water destroy the accumulations of dirt, typically consisting of paper and ink particles, located on the nozzle mouthpiece 13 or on the nozzle insert 14.
The vibration-damping components 29, 6 are arranged to protect the nozzle housing 2 as well as the crosspiece 9 supporting the nozzle unit 1 from direct ultrasonic effects.
In accordance with a variant of the above described embodiment, the vibration as seen in FIG. 1, transmitting end 34 of the vibration transmitter 32 is connected with the beginning or first or inner end of a vibration-transmitting cup 37 that is arranged coaxially with the valve rocker 19. An outer or second end 40 of the vibration-transmitting cup 37 extends as far as the nozzle mouthpiece 13 and is provided there with a centered bore 38. Because of this arrangement, during the cleaning process, the fluid 39 supplied through the valve 26 and located in the chamber 11 can pass through the outlet bore 22 as well as the nozzle insert 14 when the sealing element 21 of the valve rocker 19 has been retracted.
Because of the additional inclusion of the vibration-transmitting cup 37, it is possible to transmit the ultrasound directly as far as the vicinity of the nozzle mouthpiece 13 and therefore into the vicinity of the nozzle insert 14. Inside the chamber 11, the fluid 39 is thus in direct connection with the vibration transmitter which includes the transmitter 31, rod 32 and cup 37.
In accordance with a second preferred embodiment of the present invention, an ultrasound vibration generator 41 is arranged, fixed in place on the crosspiece 9, by means of a vibration-damping holder 42, and above a nozzle mouthpiece 13 receiving a nozzle insert 14, all as seen in FIG. 2. A rod-shaped vibration transmitter 43 connects a number of ceramic rings 33. This vibration transmitter 43 is fixedly connected, with its vibration-transmitting end 44, which is located outside of the ultrasound vibration generator 41, with a ring-shaped holder 46 that is fixedly arranged around the nozzle mouthpiece 13, or which is connected directly with the nozzle mouthpiece 13. In this case, the nozzle mouthpiece 13 can be provided with a coating 23, which is insensitive to ultrasound vibrations, on its circumference as well as on its side facing away from the nozzle insert 14, again as shown in FIG. 2.
The fluid 39 exiting from the nozzle insert 14 is in indirect contact, -via the nozzle insert 14, the nozzle mouthpiece 13, and the vibration transmitter 43 with the ultrasound vibration generator 41.
It is also possible to clean a nozzle insert 14 during the clocked or timed output of the moistening agent through the nozzle insert 14, i.e. during the opening of the electromagnetically actuated valve rocker 19, or respectively of the sealing element 21. The flowthrough amount of moistening agent through the nozzle insert 14 is a function of the press speed. With a continuous valve opening time, for example of 15 ms, a clock period length, for example of 250 ms, can be changed. By means of the permanent switching on of the ultrasound vibration generator 31 or 41 over a defined period of time, for example 30 s, the moistening agent exiting the nozzle insert 14 is activated several times by ultrasound and thus will have destroyed the paper and ink particles located at the nozzle insert 14.
The same result can be achieved if the moistening agent is in indirect contact with the ultrasound transmitter 32 or 43.
While preferred embodiments of a method and device for keeping clean ends of spray damping mechanism nozzles on a rotary printing press in accordance with the present invention have been set forth fully and completely hereinabout, it will be apparent to one of skill in the art that a number of changes in, for example, the types of printing press used, the specific type of printing being done, the fluid supply system and the like may be made without departing from the true spirit and scope of the present invention which is accordingly to be limited only by the following claims. | Deposits are removed from the end of a spray dampening nozzle which is used to spray pressurized fluid that is delivered to the nozzle end. This fluid is activated by ultrasound before it exits the nozzle end. The activation of the fluid can be accomplished upstream of, or at the nozzle end. An ultrasound vibrator is used to activate the fluid and is either directly or indirectly connected to the fluid by a vibration transmitter. | 1 |
CROSS-REFERENCE TO RELATED APPLICATION
This application is a continuation-in-part of U.S. patent application Ser. No. 08/498,663 filed Jul. 3, 1995 now abandoned.
BACKGROUND OF THE INVENTION
The present invention relates generally to construction devices and, more particularly, to construction devices involving the installation and finishing of ceilings.
One of the final activities in the construction process prior to the substantial completion of a project is the finishing work. The finishing work includes many individual efforts which, in effect, gives the project a distinctive personality and character. In projects where aesthetics are very important, mainly residential and, sometimes, commercial, the finishing of the ceiling of a room requires a great deal of attention. Although there is a wide variety of ceiling tiles available, hand textured ceilings are still in demand. These types of ceilings require a worker to manually apply with a brush material to a ceiling and, in so doing, produce a textured design. This application is difficult, not only due to the fact that the worker must awkwardly reach above himself or herself to reach the ceiling with the brush or other applicating device, but also due to the fact that he or she must manipulate the brush while in that awkward position to develop the distinctive designs. Such manipulation requires the worker to apply the ceiling material in a rapidly repeating and intermittent action of contacting and not contacting the ceiling with the applicating device. At the same time, the particular design may require the twisting or rotating of the applicating device at the time of contact with the ceiling to produce a desired effect.
This type of application is a slow, painstaking one. On projects with large ceiling areas arm fatigue will affect the rate of production and, therefore, is a major factor in labor costs. Also, in the event the ceiling is high, the worker must use a ladder or scaffold and be in the awkward position several feet above the floor. This combined with the prevalence of arm fatigue creates a dangerous situation where the worker may loose his or her balance and fall resulting in a severe or critical injury.
U.S. Pat. No. 1,712,579 to Nichols, discloses a window cleaning appliance which teaches a reciprocating member or rod. Nichols' patent, though, does not disclose a reciprocating means that is adjustable. It does teach the ability to change the length of the handle to reach larger or higher located windows. This, though, does not affect or modify the length of the `throw` of the reciprocating action which, not only addresses the length that the device can reach, but also, the amount of pressure on the ceiling which directly affects arm fatigue and the type and character of the design. U.S. Pat. No. 2,670,577 to McDonough and U.S. Pat. No. 3,268,935 disclose apparatus for supporting power devices to allow a worker to perform his or her tasks from the floor instead of on a ladder or scaffold. Neither of these patents disclose or claim a reciprocating means, whether adjustable or not, and, actually address only rotating power devices. They would not satisfy the need for a device that adequately addresses the specific demands of ceiling texturing or stippling.
Therefore, a need exists for a ceiling texturing device that allows the application of material to the ceiling in a safe and efficient manner and without the worker being in an awkward position and reducing the amount of fatigue the worker experiences.
SUMMARY OF THE INVENTION
The present invention provides a system to satisfy the aforementioned need.
Accordingly, the present invention is directed to a ceiling texturing device, comprising a variable speed drive means, a drive shaft attached to the drive means whereby the drive means rotates the drive shaft, an adjustable reciprocating means attached to the drive shaft such that the rotating motion of the drive shaft is converted to reciprocating motion and the amount of reciprocating motion can be selectively varied, a piston rod attached to the adjustable reciprocating means such that the adjustable reciprocating means moves the piston rod in a reciprocating motion and ceiling texturing means attached to the piston rod such that the piston rod moves the ceiling texturing means in a reciprocating motion.
In another aspect, the invention is directed to a ceiling texturing device comprising drive means, a drive shaft attached to the drive means whereby the drive means rotates the drive shaft, a right angle drive gear attached to the drive shaft such that the drive shaft rotates the right angle drive gear. A crank having a plurality of predeterminately spaced attachment holes is attached to the right angle drive gear such that the right angle drive gear rotates the crank. A rod bearing is attached to the crank at one of the attachment holes with a connecting arm having first and second ends attached to the rod bearing at the first end such that when the crank rotates it moves the first end of the connecting arm in a circular motion resulting in the second end of the connecting arm moving in a reciprocating motion, the amount of the reciprocating motion varies depending upon which attachment hole the rod bearing is attached. A piston rod is attached to the second end of the connecting arm such that the connecting arm moves the piston rod in a reciprocating motion. Ceiling texturing means is attached to the piston rod such that the piston rod moves the ceiling texturing means in a reciprocating motion.
In yet another aspect, the invention is directed to a ceiling texturing device comprising drive means, a drive shaft attached to the drive means whereby the drive means rotates the drive shaft, a right angle drive gear attached to the drive shaft such that the drive shaft rotates the right angle drive gear. A crank having a plurality of predeterminately spaced attachment holes is attached to the right angle drive gear such that the right angle drive gear rotates the crank. A rod bearing is attached to the crank at one of the attachment holes with a connecting arm having first and second ends attached to the rod bearing at the first end such that when the crank rotates it moves the first end of the connecting arm in a circular motion resulting in the second end of the connecting arm moving in a reciprocating motion, the amount of the reciprocating motion varies depending upon which attachment hole the rod bearing is attached. A piston rod having a first connector is attached to the second end of the connecting arm by a wrist pin such that the connecting arm moves the piston rod in a reciprocating motion toward and away from the crank. A cable having first and second ends is enclosed in a cable sleeve having a second connector whereby the first end of the cable is connected to the piston rod at the first connector and the cable passes through the second connector. A ceiling texturing means having a head connector and a head sleeve attached thereto whereby the second end of the cable is connected to the ceiling texturing means at a head connector and whereby the head sleeve is larger than the cable sleeve to allow the head sleeve to move over the cable sleeve. First spring attaches to the second connector on the cable sleeve and the head connector on the ceiling texturing means such that the cable passes through the first spring and whereby when the piston rod moves in a direction toward the crank it pulls on the cable, and also forces the ceiling texturing means toward the crank, thereby compressing the first spring. When the piston rod moves away from the crank, compression is taken off of the first spring and the first spring forces the ceiling texuring means in the direction away from the crank thereby imparting a reciprocating motion to the head sleeve and the ceiling texturing means.
BRIEF DESCRIPTION OF THE DRAWINGS
Further features of the present invention will become apparent to those skilled in the art to which the present invention relates from reading the following specification with reference to the accompanying drawings in which:
FIG. 1 is an elevation view of the present invention.
FIG. 2 is a detail view of the adjustable reciprocating means.
FIG. 3 is a detail view of the present invention mounted on a movable platform.
FIG. 4 is an elevation view of another embodiment of the present invention
FIG. 4A is detail of a portion of the invention shown in FIG. 4 with a cut-away view showing internal connections.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to the drawings and, particularly FIG. 1, there is shown an elevation of the present invention 10. Drive means 12 attaches to a drive shaft 14. The drive shaft 14 may be stiff or flexible, but in FIG. 1 it is shown as stiff. The drive shaft 14 terminates in a right angle drive gear 16 which connects to adjustable reciprocating means 18. The drive shaft 14 is enclosed in a sleeve 20. In the preferred embodiment of the present invention 10, the sleeve 20 extends from the drive means 12 to the right angle drive gear 16 to which it attaches. In the preferred embodiment of the present invention 10, the adjustable reciprocating means 18 has a crank 22, a rod bearing 24 with a connecting arm 26. The connecting arm 26 connects to a piston rod 28 using a wrist pin 30. Ceiling texturing means 32 is attached to the piston rod 28. The drive means 12 rotates the drive shaft 14. The drive shaft 14 rotates the right angle drive gear 16 which, in turn, rotates the adjustable reciprocating means 18. The adjustable reciprocating means 18 converts the rotating motion into reciprocating motion. The adjustable reciprocating means 18 transfers the reciprocating motion to the piston rod 28 through the crank 22, connecting arm 26 and the rod bearing 24. The connecting arm 26 drives the piston rod 28, in a reciprocating motion, toward and away from the crank 22 which moves the ceiling texturing means 32 in the same reciprocating motion. The piston rod 28 reciprocates through a piston guide 34. The piston guide 34 is attached to the right angle drive gear 16 by a support 36. The drive means 12 is variable speed and can be an electric motor or pneumatically or hydraulically powered. Advantageously, the drive means 12 is a 1/2 horsepower motor. In order to operate the present invention 10, the operator grasps the sleeve 20 and the support 36 and directs the ceiling texturing means 32 to the point of the ceiling that is intended to have a textured finish. The ceiling texturing means 32 may be a brush, sponge or any other means used to apply texturing material.
Referring now to FIG. 2 there is shown a detail view of the adjustable reciprocating means 18 of the present invention 10. The adjustable reciprocating means 18 is composed of a crank 22 having a plurality of predeterminately spaced attachment holes 38. The first end 40 of the connecting arm 26 is attached to rod bearing 24 which is then connected to one of the attachment holes 38. The second end 42 of the connecting arm 26 is connected through a wrist pin 30 to the piston rod 28. As the right angle drive gear 16 rotates it rotates the crank 22 resulting in the first end 40 of the connecting arm 26 moving in a circular path with the rotation of the crank 22. This circular movement of the first end 40 of connecting arm 26 imparts a reciprocating motion on the second end 42 of the connecting arm 26. The length of the reciprocating motion is equal to the diameter of the circle traced by the first end's 40 circular motion. The attachment holes 38 are located at various predetermined distances "r" from the point at which the right angle drive gear 16 connects to the crank 22. The distance "r" is the radius of the circular motion. Therefore, attaching the first end 40 of the connecting arm 26 and rod bearing 24 to a particular attachment hole 38 will determine the radius and diameter of the circle traced by the circular motion of the first end 40 of the connecting arm 26 and the amount of the reciprocating motion imparted on the second end 42 of the connecting arm 26. The amount of reciprocating motion of the second end 42 of the connecting arm 26 will be the same as the length of throw, and reciprocating speed, of the piston rod 28 and, ultimately, the ceiling texturing means 32 (not shown on FIG. 2).
Referring now to FIG. 3, there is shown another preferred embodiment of the present invention 10. In FIG. 3 the present invention 10 is shown with a movable platform 66. In this embodiment the drive means 12 is mounted on the movable platform 66. The drive shaft 14 is flexible. As in FIG. 1, the drive shaft 14 is enclosed in a sleeve 20 but in this embodiment the sleeve 20 encloses only a portion of the drive shaft 14. The right angle drive gear 16; adjustable reciprocating means 18 with its crank 22, rod bearing 24 and connecting arm 26; piston rod 28; and piston guides 34 are connected and operate in the same manner as described with reference to FIG. 1. In this embodiment, the movable platform 66 with the drive means 12 mounted thereon is moved to a location in the area where the ceiling is to be textured. The operator grasps the present invention 10 by the sleeve 20 and support 36 and directs the ceiling texturing means to the area of the ceiling to be textured. In this embodiment, though, the operator does not have to lift the drive means 12 to operate the present invention 10. Typically, the operator will position the movable platform 66 with the drive means 12 centrally in the area to be textured. The operator will then have a range of motion dependent upon the length of the drive shaft 12. The drive shaft 12 can be any size but in this embodiment of the present invention 10 it is 1/2 inches in diameter by 10 feet long.
Referring now to FIG. 4 and FIG. 4A, there is shown in elevation another embodiment of the present invention 10, and a detail of a portion of the invention with a cut-away view showing internal connections, respectively. Drive means 12, drive shaft 14, right angle drive gear 16, adjustable reciprocating means 18, crank 22, rod bearing 24, connecting arm 26, piston rod 28, and wrist pin 30 are connected and operate in the same manner as describes when discussing FIG. 1. In this embodiment, though, piston rod 28 connects to first end 44a of cable 44 at first connector 46. The piston rod 28 and cable 44 are enclosed in cable sleeve 48. A second connecter 50 is attached to one end of the cable sleeve 48 and the cable 44 passes through the second connecter 50 with the second end 44b of the cable 44 connecting to head connecter 52. Head connecter 52 attaches to ceiling texturing means 32 One end of first spring 54 attaches to second connecter 50 with the other end attaching to head connecter 52. Head sleeve 56 attaches to ceiling texturing means 32 and is sized larger than cable sleeve 48 such that the head sleeve 56 fits over the cable sleeve 48. Cable sleeve 48 has a guide 58 which travels through a slot 60 in head sleeve 56.
When the piston rod 28 moves toward the crank 22 it pulls on cable 44, which, since the cable 44 is connected to the ceiling texturing means 32, also forces the ceiling texturing means 32 toward the crank 22, thereby compressing the first spring 54. When the piston rod 28 moves away from the crank 22, compression is taken off of the first spring 54 and it forces the ceiling texuring means 32 away from the crank 22, thereby imparting a reciprocating motion to the ceiling texturing means 32. The head sleeve 56 is connected to the ceiling texturing means 32 and, therefore, moves in the same fashion therewith. The head sleeve 56 moves over the cable sleeve 48. The slot 60 in the head sleeve 56 is formed such that when the head sleeve 56 moves in a reciprocating motion the guide 58 on the cable sleeve 48 imparts a twisting motion to the head sleeve 56 and therefore, the ceiling texturing means 32. Bracket 62 is attached to sleeve 20 and cable sleeve 48. Second spring 64 is connected to cable sleeve 48 and piston rod 28. The second spring 64 keeps tension on the piston rod 28 and the wrist pin 30. Second spring 64 can also be connected between piston rod 28 and bracket 62. The second spring 64 provides for a taut connection between crank 22, connecting arm 26 and piston rod 28 and precludes the connecting arm 26 from binding with the piston rod 28.
Now that the invention has been described, variations and modifications will become apparent to those skilled in the art. It is intended that such variations and modifications be encompassed within the scope of the appended claims. | A ceiling texturing device, comprising a drive, a drive shaft attached to the drive whereby the drive rotates the drive shaft, adjustable reciprocating device attached to the drive shaft such that the rotating motion of the drive shaft is converted to reciprocating motion and the amount of reciprocating motion can be selectively varied, a piston rod attached to the adjustable reciprocating device such that the adjustable reciprocating device moves the piston rod in a reciprocating motion and a ceiling texturing device attached to the piston rod such that the piston rod moves the ceiling texturing device in a reciprocating motion. | 1 |
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