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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to internal clock signal generation circuits, and more particularly to a circuit and method that can produce an internal clock signal correctly in synchronization with an external clock signal.
2. Description of Related Art
When a system with a semiconductor memory device is operated at high speed, it is important to take into account a skew between a clock signal that the semiconductor memory device externally receives and data output from the semiconductor memory device, in order to correctly transfer the data output from the semiconductor memory device to an external processing device.
Typically, the semiconductor memory device includes an internal clock generation circuit to generate an internal clock signal in synchronization with an external clock signal, thereby minimizing the skew. The internal clock generation circuit typically includes a phase-locked loop circuit and a delay-locked loop circuit.
Unfortunately, the phase-locked loop circuit requires several hundred clock signals; and the delay-locked loop circuit is serially connected to a plurality of unit delay circuits comprising each of a pair of inverters, resulting in increased layout area and complexity of the circuit.
SUMMARY OF THE INVENTION
An advantage of the present invention is to provide a circuit and method that can produce an internal clock signal correctly in synchronization with an external clock signal without using a plurality of unit delay circuits, thereby simplifying the structure of the circuit.
To achieve this advantage of the present invention, an internal clock signal generation circuit comprises a first delay means for delaying an external clock signal by a first delay time; a divider for dividing an output signal from the first delay means; a first signal generation means for producing a first signal with a pulse width equivalent to a skew monitor time, by delaying an output signal from the divider by a second delay time (e.g., the first delay time+a third delay time+a fourth delay time) and by combining the output signal from the divider with a signal delayed by the second delay time; a second signal generation means for producing a second signal with a pulse width equivalent to the third delay time at a falling (or rising) edge of the output signal from the first delay means; a time/digital signal converter means for converting the skew monitor time equivalent to the pulse width of the first signal into a first and a second digital signals in response to the first signal; and a digital signal/time converter means for reproducing the skew monitor time by inputting the first and second digital signals in response to the second signal, and outputting an internal clock signal being delayed by the fourth delay time from the skew monitor time reproduced.
Furthermore, the time/digital signal converter comprises a first ring oscillator for generating in response to the first signal n number of first pulse signals, the first ring oscillator including n number of first inverting circuits serially connected; a transmitter for outputting in response to a falling (or rising) edge of the first signal the n number of the first pulse signals; a phase detector for detecting phases of the n number of the first pulse signals to produce the first digital signal; and a first counter for counting in response to a falling (or rising) edge of a n th pulse signal of the n number of the first pulse signals to produce the second digital signal.
The digital signal/time converter comprises a set/reset signal generation means that produces a set signal, if the first digital signal is at an even state, and produces a reset signal, if the first digital signal is at an odd state; a second ring oscillator for generating in response to the second signal and the set signal n number of second pulse signals being oscillated with a first type, and for generating in response to the second signal and the reset signal the n number of the second pulse signals being oscillated with a second type, the second ring oscillator including n number of second inverting circuits connected in series; a select control signal generation means for producing n number of control signals to output selectively a corresponding pulse signal of the second pulse signals for the case where the first digital signal is produced by detecting rising (or falling) edges of a 1 st pulse signal to the n th pulse signal of the first pulse signals, and output selectively a (corresponding order+1) th pulse signal of the second pulse signals for the case where the first digital signal is produced by detecting falling (or rising) edges of the 1 st pulse signal to the n th pulse signal of the first pulse signals; a selection means for selecting one pulse signal of the n number of the second pulse signals output from the second ring oscillator in response to the n number of the control signals; a second counter for counting in response to an output signal from the selection means; and a comparison means for comparing an output signal of the first counter with an output signal of the second counter, and delaying and outputting the output signal of the selection means by the fourth delay time, if the output signal of the first counter is equal to the output signal of the second counter.
To achieve a further advantage of the present invention, a method for generating an internal clock signal comprises generating a first clock signal by delaying an external clock signal by a first delay time; generating a second clock signal by dividing the first clock signal; generating a third clock signal by delaying the second clock signal by a second delay time (the first delay time+a third delay time+a fourth delay time), and generating a first signal with a pulse width equivalent to a skew monitor time in combination with the second clock signal and the third clock signal; generating a second signal with a pulse width equivalent to the third delay time at a falling (or rising) edge of the first clock signal; converting the skew monitor time equivalent to the pulse width of the first signal into a first and a second a digital signals in response to the first signal; and reproducing the skew monitor time by inputting the first and the second digital signals in response to the second signal, and generating the internal clock signal being delayed by the fourth delay time from the skew monitor time reproduced.
Preferably, the time/digital signal converting comprises generating n number of first pulse signals being oscillated in response to the first signal; outputting the n number of the first pulse signals in response to a falling (or rising) edge of the first signal; and detecting phases of the n number of the first pulse signals to produce the first digital signal, and counting in response to a falling (or rising) edge of a n th pulse signal of the n number of the first pulse signals to produce the second digital signal.
Preferably, the digital signal/time converting comprises producing a set signal, if the first digital signal is at an even state, and producing a reset signal, if the first digital signal is at an odd state; outputting selectively a corresponding pulse signal of the second pulse signals for the case where the first digital signal is produced by detecting rising (falling) edges from a 1 st pulse signal to the n th pulse signal of the first pulse signals, and outputting selectively a (corresponding number+1) th pulse signal of the second pulse signals for the case where the first digital signal is produced by detecting falling (or rising) edges from the 1 st pulse signal to the n th pulse signal of the first pulse signals; generating n number of the second pulse signals being oscillated with a first type in response to the second signal and the set signal, and generating the n number of the second pulse signals being oscillated with a second type in response to the second signal and the reset signal; selecting one pulse signal of the n number of the second pulse signals in response to n number of control signals to output a selected output signal; counting in response to the selected output signal to produce a third digital signal; and comparing the second digital signal with the third digital signal, and delaying and outputting the selected output signal by the fourth delay time, if the second digital signal is equal to the third digital signal.
Other aspects, features and advantages of the present invention are disclosed in the detailed description that follows.
BRIEF DESCRIPTION OF THE DRAWINGS
For a more complete understanding of the present invention and the advantages thereof, reference is now made to the following description taken in conjunction with the accompanying drawings, in which like reference numerals designate like elements, and in which:
FIG. 1 shows a block diagram of an internal clock signal generation circuit according to an embodiment of the present invention;
FIG. 2 shows a block diagram representing a structure of a time/digital signal converter and a digital signal/time converter of FIG. 1;
FIG. 3 shows a block diagram representing a structure of the time/digital signal converter and the digital signal/time converter according to the embodiment of FIG. 2;
FIG. 4 shows a detailed circuit diagram of a ring oscillator according to the embodiment of FIG. 2;
FIG. 5 shows a detailed circuit diagram of another ring oscillator according to the embodiment of FIG. 2;
FIGS. 6 through 11 are timing charts for explaining the operation of the internal clock signal generation circuit according to the present invention; and
FIG. 12 shows a block diagram of the time/digital signal converter and the digital signal/time converter of FIG. 2 according to another embodiment of the present invention.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
Preferred embodiments of the present invention will now be described with reference to the accompanying drawings. Like reference numerals in the drawings designate like elements.
As shown in FIG. 1, a block diagram of an internal clock signal generation circuit according to an embodiment of the present invention is indicated generally by the reference numeral 100 . The internal clock signal generation circuit 100 includes a first delay circuit 10 , a divider 12 , a pulse generation circuit 14 including a second delay circuit 14 - 1 and an AND gate 14 - 2 , a pulse generation circuit 16 , a time/digital signal converter 18 and a digital signal/time converter 20 .
The first delay circuit 10 delays an external clock signal ECLK by a first delay time d 1 to produce a clock signal RCLK. The divider 12 divides the clock signal RCLK by 2 to produce a clock signal DCLK. The second delay circuit 14 - 1 delays the clock signal DCLK by a delay time tD to produce a clock signal dCLK. The delay time tD is set to time d 1 +d 2 +d 3 . The AND gate 14 - 2 receives the clock signal DCLK and the clock signal dCLK to output a signal E 1 with the pulse width of time(tM=tC−tD, tC indicates a period of the external clock signal ECLK). The time tM indicates a skew monitor delay time. The pulse generation circuit 16 generates a negative pulse signal E 2 with the pulse width of the time d 2 at the rising edge of the clock signal RCLK. The time/digital signal converter 18 receives the signal E 1 to convert the skew monitor delay time tM into digital signals r and m. The digital signal r is a value for fine delay, and the digital signal m is a value for coarse delay. The digital signal/time converter 20 receives the signal E 2 and the digital signals r and m to convert the digital signals r and m into the skew monitor delay time tM in response to the signal E 2 and generates an internal clock signal ICLK. In other words, the digital signal/time converter 20 reproduces the skew monitor delay time tM at the rising edge of the signal E 2 using the digital signals r and m and then produces the internal clock signal ICLK being delayed by the delay time d 3 from the skew monitor delay time reproduced.
Turning to FIG. 2, a block diagram representing a structure of the time/digital signal converter and the digital signal/time converter of FIG. 1 is indicated generally by the reference numeral 200 . In the converter pair 200 , a time/digital signal converter 18 comprises a ring oscillator 30 , a transmitter 32 , a phase detector 34 , and a first counter 36 . The digital signal/time converter 20 comprises a ring oscillator 38 , a selector, a comparator 42 , a set/reset signal generation circuit 44 , a select control signal generation circuit 46 , and a second counter 48 .
In operation of the converter pair 200 , the ring oscillator 30 produces a plurality of pulse signals S 1 through Sn in response to the signal E 1 . The transmitter 32 transmits the pulse signals S 1 through Sn as signals P 1 through Pn at the falling edge of the signal E 1 . The phase detector 34 outputs 2n number of the digital signals r on phases of the signals P 1 through Pn, i.e. the phase detector 34 detects signals Pn and Pn+1 at the rising edge of the pulse signal Sn and detects inverted signals PnB and P(n+1)B at the falling edge of the pulse signal Sn. The first counter 36 counts in response to the falling edge of the pulse signal Sn to output the digital signal m. The skew monitor delay time tM is decided by the digital signal m. If a signal propagation delay time each of the inverters in the ring oscillator is tpd, the skew monitor time tM is (2 nm +r)×tpd. Also, the term 2n×tpd is a period t 0 of the signals S 1 through Sn which are produced by the ring oscillator 30 . The ring oscillator 38 is fixed to the same initial state as the signals S 1 through Sn in response to the signal E 2 of a LOW (“L”) level and a reset signal R of a HIGH (“H”) level, and generates pulse signals VS 1 through VSn toggling with the same delay time as the signals S 1 through Sn in response to the signal E 2 of the “H” level. The ring oscillator 38 also fixes the initial states of the pulse signals VS 1 through VS(n−1) at the “H” level and the initial state of the pulse signal VBn at the “L” level in response to the signal E 2 of the “L” level and a set signal S of a “H” level, and generates the pulse signals VS 1 through VSn toggling after being delayed from the initial state by time ntpd and tpd through (n−1)tpd in response to the signal E 2 of the “H” level. At this time, the ring oscillator 38 generates the pulse signals VS 1 through VSn with the same period and duty cycle as the ring oscillator 30 . The set/reset signal generation circuit 44 produces the set signal S, when the digital signal r is produced by detecting the inverted signals PnB and P(n+1)B at the falling edge of the pulse signal Sn, and produces the reset signal R, when the digital signal r is produced by detecting the signals Pn and Pn+1 at the rising edge of the pulse signal Sn. The select control signal generation circuit 46 produces control signals C 1 through Cn to output selectively the corresponding pulse signals VS 1 through VSn in case that the digital signal r is produced by detecting the rising edges of the pulse signals S 1 through Sn, and produces the control signals C 1 through Cn to output selectively the corresponding pulse signals VS 2 through VSn and VS 1 in case that the digital signal r is produced by detecting the falling edges of the pulse signals S 1 through Sn. The selector 40 selects one of the signals VS 1 through VSn in response to the control signals C 1 through Cn to output a signal SOUT. The second counter 48 counts in response to the signal SOUT to output a signal Vm. The comparator 42 compares the signal Vm with the digital signal m, and if the signal Vm is equal to the digital signal m, inputs the signal SOUT to output the internal clock signal ICLK. The comparator 42 receives the signal SOUT that is delayed by the skew monitor delay time tM in response to the signal E 2 and delays it by the delay time d 3 to generate the internal clock signal ICLK.
Turning now to FIG. 3, a block diagram representing a structure of the time/digital signal converter and the digital signal/time converter according to an embodiment of FIG. 2 is indicated generally by the reference numeral 300 . Here, the ring oscillator includes inverters I 1 , I 1 and I 3 . The transmitter 32 includes flip-flops F/F 1 , F/F 2 and F/F 3 . In addition, the ring oscillator 38 includes inverters I 4 , I 5 and I 6 . The selector 40 includes multiplexers MUX 1 , MUX 2 and MUX 3 .
In operation of the converter pair 300 , the ring oscillator 30 produces the pulse signals S 1 , S 2 and S 3 in response to the signal E 1 . At this time, the inverters I 1 , I 2 and I 3 in the oscillator 30 have same delay time each other. The first counter 36 counts in response to the falling edge of the pulse signal S 3 to produce the digital signal m. The flip flops F/F 1 , F/F 2 and F/F 3 receive the pulse signals S 1 , S 2 and S 3 in response to the falling edge of the signal E 1 to generate the signals P 1 , P 2 and P 3 , respectively. The phase detector 34 produces six digital signals r “000001”, “000010”, “000100”, “001000”, “010000”, “100000” according to the phases of the signals P 1 , P 2 and P 3 . In other words, when the phase of the signals P 1 , P 2 and P 3 input to the phase detector 34 are “H” level, “H” level, and “L” level, respectively, the digital signal r is “000001. When the phases of the signals P 1 , P 2 and P 3 are “H” level, “L” level and “L” level, the digital signal r is “000010”. When the phases of the signals are “H” level, “L” level and “H” level, the digital signal r is “000100”. When the phases of the signals are “L” level, “L” level and “H” level, the digital signal r is “001000”. When the phases of the signals are “L” level, “H” level and “H” level, the digital signal r is “010000” and when the phases of the signals are “L” level, “H” level and “L” level, the digital signal r is “100000”. At this time, the produced digital signal r is irrespective of a 3-bit signal representing six different kinds of signals. The ring oscillator 38 generates the pulse signals VS 1 , VS 2 and VS 3 in response to the signal E 2 . At this time, the inverters I 4 , I 5 and I 6 in the ring oscillator 38 have the same delay time as the inverters I 1 , I 2 and I 3 in the ring oscillator 30 . The set/reset generation circuit 44 generates the set signal S, when the digital signal r is “000010”, “001000”, “100000”, and generates the reset signal R, when the digital signal r is “000001”, “000100”, “010000”. The select control signal generation circuit 46 generates the control signal C 1 , when the digital r is “100000”, “000001”, generates the control signal C 3 , when the digital signal r is “000010”, “000100”, and generates the control signal C 2 , when the digital signal r is “001000”, “010000”. The multiplexers MUX 1 , MUX 2 and MUX 3 output a signal SOUT by selecting one of the signals VS 1 , VS 2 and VS 3 in response to the control signals C 1 , C 2 and C 3 . The second counter 48 counts in response to the signal SOUT to output the signal Vm. The comparator 42 compares the signal Vm with the signal m, and if the signal Vm is equal to the signal m, receives the signal SOUT to produce the internal clock signal ICLK.
As shown in FIG. 4, a detailed circuit of the ring oscillator 30 according to an embodiment of FIG. 2 is indicated generally by the reference numeral 400 . The ring oscillator 400 includes an inverter I 1 including an inverter I 7 , PMOS transistors P 1 , P 2 and P 3 and NMOS transistors N 1 , N 2 and N 3 , an inverter I 2 including PMOS transistors P 4 , P 5 and P 6 and NMOS transistors N 4 , N 5 and N 6 , and an inverter I 3 including PMOS transistors P 7 , P 8 and P 9 and NMOS transistors N 7 , N 8 and N 9 .
The operation for each of the blocks of the oscillator 400 will now be described in detail. When the signal E 1 of the “L” level is input to the inverter I 7 , the invert I 7 generates a signal E 1 B of the “H” level. Accordingly, the PMOS transistors P 1 and P 4 and NMOS transistors N 2 and N 5 are OFF, and the NMOS transistor N 3 and PMOS transistor P 6 are ON. The inverter I 1 generates the signal S 1 of the “L” level, and the inverter I 2 generates the signal S 2 of the “H” level. And, the inverter I 3 inverts the signal S 2 of the “H” level to output the signal S 3 of the “L” level. In other words, when the signal E 1 of the “L” level is input to the inverter I 7 , the signals S 1 , S 2 and S 3 are fixed to the “L” level, the “H” level, and the “L” level, respectively.
When the signal E 1 of the H level is input to the inverter I 7 , the inverter I 7 produces the signal E 1 B of the “L” level. Accordingly, the PMOS transistors P 1 and P 4 and NMOS transistors N 2 and N 5 are ON, and the NMOS transistor N 3 and PMOS transistor P 6 are OFF. Thus, the operation of the inverters I 1 and I 2 will be enabled. So, the inverter I 1 inverts and delays the signal S 3 to output the signal S 1 and the inverter I 2 inverts and delays the signal S 1 to output the signal S 2 , and the inverter I 3 inverts and delays the signal S 2 to output the signal S 3 . Accordingly, when the delay time each of the inverters I 1 , I 2 and I 3 is equal to the time td, if the signal E 1 of the H level is provided, the inverters I 1 , I 2 and I 3 produce the pulse signals S 1 , S 2 and S 3 with the duty cycle of 50% and the period of 6td. The pulse signals S 1 , S 2 , S 3 are individually the signals toggling in order with the delay time td from the rising edge of the signal E 1 .
Turning to FIG. 5, a detailed circuit of a ring oscillator 38 according to the embodiment of FIG. 2, constituted of the same elements as those of the ring oscillator 400 of FIG. 4, is indicated generally by the reference numeral 500 . The ring oscillator 500 differs from the ring oscillator 400 in that an inverted set signal SB is input to a gate of the PMOS transistor P 3 and the reset signal R is input to a gate of the NMOS transistor N 3 in the ring oscillator 38 .
In operation of the circuit 500 , when the signal E 2 of the L level is input to an inverter I 8 , the inverter I 8 produces a signal E 2 B of the “H” level. Accordingly, the PMOS transistors P 1 and P 4 and NMOS transistors N 2 and N 5 are OFF, and the PMOS transistor P 6 is ON. At this time, if the inverted set signal SB and the reset signal R are at the “H” level, the PMOS transistor P 3 is OFF and the NMOS transistor N 3 is ON, thereby producing the signal VS 1 of the “L” level. Also, the PMOS transistor P 6 is ON to produce the signal VS 2 of the “H” level. The inverter I 6 inverts and delays the signal VS 2 of the “H” level to produce the signal VS 3 of the “L” level. In other words, the signals VS 1 , VS 2 and VS 3 are individually fixed to the “L” level, “H” level and “L” level. On the contrary, if the inverted set signal SB and the reset signal R are at the “L” level, the signals VS 1 , VS 2 and VS 3 are individually fixed to the “H” level, the “H” level and the “L” level.
When the signals VS 1 , VS 2 and VS 3 are individually fixed to the “L” level, the “H” level and the “L” level, if the signal E 2 is driven to an “H” level and the inverted set signal of the “H” level and the rest signal R of the “L” level are produced, the PMOS transistors P 1 and P 4 and the NMOS transistors N 2 and N 5 are ON and the PMOS transistors P 3 and P 6 and the NMOS transistors N 3 are OFF. The inverter I 4 inverts and delays the signal VS 3 to generate the signal VS 1 , the inverter I 5 inverts and delays the signal VS 1 to generate the signal VS 2 , and the inverter I 6 inverts and delays the signal VS 2 to generate the signal VS 3 . Accordingly, when the delay time each of the inverters I 4 , I 5 and I 6 is equal to the time td, if the signal E 2 of the “H” level is provided, the inverters I 4 , I 5 and I 6 produce the pulse signals VS 1 , VS 2 and VS 3 with the duty cycle of 50% and the period of 6 td. The pulse signals VS 1 , VS 2 and VS 3 are the signals toggling in order with the delay time td, after the signal E 2 is driven to the “H” level.
Conversely, when the signals VS 1 , VS 2 and VS 3 are individually fixed to the “H” level, the “H” level and the “L” level, if the signal E 2 is driven to the “H” level, and if the inverted set signal SB of the “”H” level and the reset signal R of the “L” level is produced, the inverter I 4 inverts and delays the signal VS 3 to produce the signal VS 1 , the inverter I 5 inverts and delays the signal VS 1 to produce the signal VS 2 , and the inverter I 6 inverts and delays the signal VS 2 to produce the signal VS 3 . Accordingly, when the delay time each of the inverters I 4 , I 5 and I 6 is equal to the time td, if the signal E 2 of the “H” level is provided, the inverters I 4 , I 5 and I 6 produce the pulse signals VS 2 , VS 3 , and VS 1 with the duty cycle of 50% and the period of 6 td. At this time, the pulse signals VS 1 , VS 2 and VS 3 are the signals toggling in order with the delay time 3 td, after the signal E 2 is driven to the “H” level.
FIGS. 6 through 11 show timing charts for explaining the operation of the internal clock signal generation circuit according to embodiments of the present invention, indicated generally by the reference numerals 600 , 700 , 800 , 900 , 1000 and 1100 , respectively.
Referring back to FIG. 1 and FIG. 3, operation of the circuits 100 and 300 will now be described with respect to the timing charts.
As shown in FIG. 6, the operation of the internal clock signal generation circuit according to the present invention will be described with reference to the timing chart 600 .
The first delay circuit 10 delays the external clock signal ECLK by the first delay time d 1 . The divider 12 divides the signal RCLK by 2 to produce the signal DCLK. The second delay circuit 14 delays the signal DCLK by the second delay time (tD=d 1 +d 2 +d 3 ). An AND gate 14 - 2 receives the signal DCLK and the signal dCLK to produce the signal E 1 with the pulse width of the skew monitor delay time (tM=tC−tD, where tC indicates a period of the external clock signal ECLK). The pulse generation circuit 10 generates the negative pulse signal E 2 with the pulse width of the time d 2 at the rising edge of the signal RCLK. The ring oscillator 30 generates the pulse signals S 1 , S 2 and S 3 toggling in the response to the signal E 1 of the “H” level. The flip-flops F/F 1 , F/F 2 and F/F 3 transmit the signals S 1 , S 2 and S 3 of the “L” level, the “H” level and the “L” level at the falling edge of the signal E 1 . The phase detector 34 outputs the digital signal r of “100000”. The first counter 36 counts in response to the falling edge of the pulse signal S 3 to produce the digital signal m of “10”. At this time, the produced digital signals r and m are the digital values for the skew monitor delay time tM. The set/reset signal generation circuit 44 generates the reset signal R and the inverted set signal SB maintaining the “L” level during the time period of the signal E 2 of the “L” level, if the digital signal r of “100000” is input to the circuit 44 . The select control signal generation circuit 46 inputs the digital signal r of “100000” to generate the control signal C 1 of the “H” level and the control signals C 2 and C 3 of the “L” level. The ring oscillator 38 generates the pulse signals VS 1 , VS 2 and VS 3 toggling in response to the signal E 2 of the “H” level. At this time, the produced pulse signals VS 1 , VS 2 and VS 3 are respectively fixed to the “H” level, the “H” level and the “L” level in response to the signal E 2 of the “L” level and the inverted signal SB of the “L” level, and are toggling after being delayed by the times 3tpd, tpd and 2tpd from the rising edge of the signal E 2 in response to the signal E 2 of the “H” level and the inverted signal SB of the “H” level. The multiplexer MUX 1 inputs the pulse signal VS 1 to produce the signal SOUT in response to the control signal C 1 . The second counter 48 counts in response to the rising edge of the signal SOUT. The comparator 42 compares an output signal of the first counter with an output signal of the second counter 48 , and if the output signal of the first counter 36 is equal to the output signal of the second counter 48 , produces the signal SOUT as the internal output signal ICLK. At this time, the comparator 42 delays the signal SOUT by the delay time d 3 to produce the internal clock signal ICLK. Accordingly, the internal clock generation circuit can produce the internal clock signal ICLK correctly in synchronization with the external clock signal ECLK.
Turning to FIG. 7, operation of the circuits 100 and 300 of FIGS. 1 and 3, respectively, will now be described with respect to the timing chart 700 , which shows a case where the skew monitor time tM is greater than the skew monitor time tM of FIG. 6 .
In this case, the time/digital signal converter 18 operates to generate the digital signal r of “000001” and the digital signal m of “10” at the falling edge of the signal E 1 . The set/reset signal generation circuit 44 inputs the digital signal r of “000001” to generate the inverted set signal SB of the “L” level and the reset signal R of the “L” level. The ring oscillator 38 generates the pulse signals VS 1 , VS 2 and VS 3 toggling in the response to the signal E 2 of the “H” level. At this time, the generated pulse signals VS 1 , VS 2 and VS 3 are respectively fixed to the “L” level, the “H” level and the “L” level in response to the signal E 2 of the “L” level and the reset signal R of the “H” level, and are toggling after being delayed by each of the times tpd, 2tpd and 30tpd from the rising edge of the signal E 2 in response to the signal E 2 of the “H” level and the reset signal R of the “L” level. The select control signal generation circuit 46 inputs the digital signal r of “000001” to generate the control signal C 1 of the “H” level and the control signals C 2 and C 3 of the “L” level. Accordingly, the multiplexer MUX 1 inputs the pulse signal VS 1 to produce the signal SOUT in response to the control signal C 1 . The second counter 48 counts in response to the rising edge of the signal SOUT. The comparator 42 compares the digital signal m with the signal Vm, and if the digital signal m is equal to the signal Vm, delays the signal SOUT by the delay time d 3 to produce the internal clock signal ICLK.
Turning now to FIG. 8, operation of the circuits 100 and 300 of FIGS. 1 and 3, respectively, will now be described with respect to the timing chart 800 , which shows a case where the skew monitor time tM is greater than the skew monitor time tM of the timing chart of FIG. 7 .
In this case, the time/digital signal converter 18 generates the digital signal r of “000010” and the digital signal m of “10”. The ring oscillator 38 generates the pulse signals VS 1 , VS 2 and VS 3 toggling in the response to the signal E 2 of the “L” level and the inverted set signal SB of the “L” level. At this time, the generated pulse signals VS 1 , VS 2 and VS 3 have the same toggling as the pulse signals VS 1 , VS 2 and VS 3 of the timing chart of FIG. 6 . The select control signal generation circuit 46 inputs the digital signal r of “000010” to generate the control signal C 3 of the “H” level and the control signals C 1 and C 2 of the “L” level. Accordingly, the multiplexer MUX 3 inputs the pulse signal VS 3 to produce the signal SOUT in response to the control signal C 3 . The second counter 48 counts in response to the signal SOUT. The comparator 42 compares the digital signal m with the signal Vm, and if the digital signal m is equal to the signal Vm, delays the signal SOUT by the delay time d 3 to produce the internal clock signal ICLK. Accordingly, the internal clock generation circuit can produce the internal clock signal ICLK correctly in synchronization with the external clock signal ECLK.
Turning now to FIGS. 9 through 11, a detailed explanation of the timing charts 900 , 1000 and 1100 is omitted due to the similarity to the description already provided. Thus, the operation in these cases will be understood and appreciated by those of ordinary skill in the pertinent art by referring to the explanation for the timing charts 600 , 700 and 800 of FIGS. 6 through FIG. 8, respectively.
As described above, the internal clock generation circuit shown for the circuit 300 of FIG. 3 has a construction such that the time/digital signal converter 18 and the digital signal/time converter 20 include the counter and the ring oscillator having three inverters, respectively.
As shown in FIG. 12, a block diagram of the time/digital signal converter and the digital signal/time converter according to another embodiment of FIG. 2 is indicated generally by the reference numeral 1200 .
In the converter circuit 1200 , the ring oscillator 30 includes inverters I 9 through I 13 , the transmitter 32 includes flip-flops F/F 1 through F/F 5 , the ring oscillator 38 includes inverters I 14 through I 18 , and the selector 40 includes multiplexers MUX 1 through MUX 5 . In operation, The ring oscillator 30 produces pulse signals S 1 through S 5 in response to the signal E 1 . At this time, the inverters I 9 through I 13 in the ring oscillator 30 have the same delay time. The counter 36 counts in response to the falling edge of the pulse signal S 3 to produce the digital signal m. The flip-flops F/F 1 through F/F 5 input the pulse signals S 1 through S 5 to generate signals P 1 through P 5 at the falling edge in the signal E 1 , respectively. The phase detector 34 generates ten digital signals r, “0000000001”, “0000000010” . . . , “1000000000” according to the phases of the signals P 1 through P 5 . In other words, if the phases of the signals P 1 through P 5 input to the phase detector 34 is “H” level, “H” level, “L” level, “H” level and “L” level, the phase detector 34 generates the digital signal r of “0000000001”. If the phases of the signals P 1 through P 5 input to the phase detector 34 is “H” level, “L” level, “L” level, “H” level and “L” level, the phase detector 34 generates the digital signal r of “0000000010”. If the phases of the signals P 1 through P 5 input to the phase detector 34 is “L” level, “H” level, “L” level, “H” level and “L” level, the phase detector 34 generates the digital signal r of “1000000000”. The ring oscillator 38 generates the pulse signals VS 1 , VS 2 , VS 3 , VS 4 and VS 5 in response to the signal E 2 . At this time, the inverters I 14 through I 18 in the ring oscillator 38 have the same delay time as the inverters ( 9 through I 13 in the ring oscillator 30 . The set/reset signal generation circuit 44 generates a set signal S, if the even bit signal of the digital signal r is “1”, and generates a reset signal R, if the odd bit signal of the digital signal r is “1”. The select control signal generation circuit 46 generates the control signal C 1 , if the 1 st bit signal and the 10 th bit signal of the digital signal r are “1”, generates the control signal C 3 , if the 2 nd bit signal and the 3 rd bit signal of the digital signals r are “1”, generates the control signal C 5 , if the 4 th bit signal and the 5 th bit signal of the digital signal r are “1”, generates the control signal C 2 , if the 6 th bit signal and the 7 th bit signal of the digital signal r are “1”, and generates the control signal C 4 , if the 8 th bit signal and the 9 th bit signal of the digital signal r are “1”. The multiplexers MUX 1 through MUX 5 select one of the signals VS 1 , VS 2 , VS 3 , VS 4 and VS 5 in response to the control signals C 1 through C 5 to generate the output signal SOUT. The second counter 48 counts in response to the signal SOUT to output the signal Vm. The comparator 42 compares the digital signal m with the signal Vm, and if the digital signal m is equal to the signal Vm, delays the signal SOUT by the delay time d 3 to produce the internal clock signal ICLK.
The timing chart of the internal clock signal generation circuit in FIG. 12 is not shown. But, using the same method as indicated for the timing charts of FIGS. 6 through FIG. 11, the internal clock signal generation circuit can produce the internal clock signal ICLK correctly in synchronization with the external clock signal ICLK.
As described above, the internal clock generation circuit according to the embodiment of the present invention shown in the circuit 1200 has a construction such that the time/digital signal converter 18 and the digital signal/time converter 20 include the counter and the ring oscillator having five inverters, respectively. In other words, the internal clock generation circuit does not include a plurality of unit delay circuit each having two inverters connected in series, but can produce the internal clock signal correctly in synchronization with the external clock signal with the construction of the circuit as shown.
Correspondingly, the ring oscillator in the internal clock signal generation circuit of FIG. 12 comprises two more inverters in comparison with the ring oscillator of FIG. 3, but may simply configure the counter, because the value of the digital signal m becomes small in case that the skew monitor time is set to the same.
According to the present invention, the internal clock signal generation circuit is constructed by the counter and the ring oscillator having relatively few inverters, thereby simplifying the structure of the circuit and reducing the layout dimensions.
Further, the internal clock signal generation circuit of the present invention is configured to produce the internal clock signal correctly in synchronization with the external clock signal with a simplified circuit structure.
While the invention has been particularly shown and described with reference to preferred embodiments thereof, it will be understood by those of ordinary skill in the pertinent art that the foregoing and other changes in form and details may be made therein without departing from the spirit and scope of the invention, as set forth in the appended claims. | The present invention discloses a circuit and a method for generating an internal clock signal, where the internal clock signal generation circuit includes a first delay portion for delaying an external clock signal by a first delay time, divides for dividing an output signal from the first delay portion, a first signal generator for generating a first signal with a pulse width equivalent to a skew monitor time by delaying an output signal from the divider by a second delay time and by combining the output signal from the divider with a signal delayed by the second delay time, a second signal generater for generating a second signal with a pulse width equivalent to a third delay time at a falling or rising edge of the output signal from the first delay portion, a time/digital signal converter for converting the skew monitor time equavalent to the pulse width of the first signal into first and second digital signals in response to the first signal, and a digital signal/time converter for reproducing the skew monitor time by inputting the first and the second digital signals in response to the second signal and generating the internal clock signal being delayed by a fourth delay time from the skew monitor time reproduced. | 6 |
FIELD OF THE INVENTION
This invention relates to a cushioned dust control mat or article. In one embodiment, the mat comprises at least two distinct layers of rubber, one comprising foam rubber, the other comprising solid rubber. The solid rubber layer is present over the foam rubber layer on the side of the mat in which at least one. integrated rubber protrusion is present to provide cushioning characteristics. The solid rubber layer acts as a cap or barrier for the foam rubber layer, particularly over the integrated protrusion or protrusions, in order to provide a mat which is resilient, will not easily degrade in its modulus strength after appreciable use and/or washing within industrial cleaning processes, and will not exhibit appreciable cracking or breaking, particularly within the integrated protrusion(s), after standard use for pedestrian traffic. A method of producing such an inventive cushioned floor mat article is also provided.
BACKGROUND
All U.S. patent cited herein are hereby fully incorporated by reference.
As described U.S. patent application Ser. No. 09/374,707, filed Aug. 13, 1999, now U.S. Pat. No. 6,340,514, and in corresponding Japan Patent Application No. 353345/99, filed Dec. 13, 1999, floor mats have long been utilized to facilitate the cleaning of the bottoms of people's shoes, particularly in areas of high pedestrian traffic such as doorways. Moisture, dirt, and debris from out of doors easily adhere to such footwear, particularly in inclement weather and particularly in areas of grass or mud or the like. Such unwanted and potentially floor staining or dirtying articles need to be removed from a person's footwear prior to entry indoors. As will be appreciated, such mats by their nature must undergo frequent repeated washings and dryings so as to remove the dirt and debris deposited thereon during use. These mats are generally rented from service entities which retrieve the soiled mats from the user and provide clean replacement mats on a frequent basis. The soiled mats are thereafter cleaned and dried in an industrial laundering process (such as within rotary washing and drying machines, for example) or by hand and then sent to another user in replacement of newly soiled mats.
Uncarpeted anti-fatigue dust control mats have been made in the past comprised of dense rubber, scrap rubber, sponge-like material, including PVC, vinyl polymers, and polyurethanes, as well as recycled tire rubber. The mats are generally not able to be washed in industrial cleaning applications (such as rotary washing machines) since they are either too heavy or dense (and thus either damage the machine or themselves) or either deteriorate too easily (since sponge-like materials are easy to tear apart, particularly in rotary cleaning applications). Such washability is a key to providing a suitable floor mat article within the standard rental laundry market. As such, it has been very difficult to produce uncarpeted cushioned floor mats which exhibit sufficient strength to withstand vigorous cleaning and laundering associated with industrial rental laundry services. Foam rubber has only recently been utilized within dust control mats as a manner of reducing the overall mass of the mat article to facilitate movement and cleaning (such as in U.S. Pat. No. 5,305,565 to Nagahama et al.). Also, cushioned mats have been produced, generally including portions of the mat which contain discrete areas of integrated rubber increasing the surface area of the mat in three axes, which thereby provide cushioned areas on which a pedestrian may step.
However, other than as described in previously mentioned U.S. application Ser. No. 09/374,70, now U.S. Pat. No. 6,340,514, and Japan application 353345/99, there have not been any mats comprising integrated rubber protrusions which not only permit repeated industrial washings without exhibiting appreciable degradation of the mat structure but also provide excellent cushioning effects to pedestrian users for more comfortable floor and ground covering as well as provide a surface to clean such pedestrians' footwear. As such, there is a need to provide an improved durable, cushioned dust control mat and method.
DESCRIPTION OF THE INVENTION
It is thus an object of this invention to provide a durable, cushioned dust control mat which permits cleaning of a pedestrian's footwear. Furthermore, it is an object of the invention to provide a durable, cushioned dust control mat in which the cushioning aspects are provided by at least one integrated rubber protrusion produced during the necessary vulcanization process. Still other objects of the invention is to provide a cushioned all-rubber floor mat which retains its cushioning characteristics and shape upon use and can be laundered repeatedly within industrial rotary washing machines without damaging such machines or themselves.
Accordingly, one embodiment of this invention encompasses a rubber floor mat structure comprising at least two separate layers of rubber wherein said at least two layers comprise
a first layer comprised of foam rubber; and
a second layer comprised of solid rubber;
wherein at least one protrusion integrated within said rubber mat structure is present having a core portion and an outside surface portion, wherein the core portion of said at least one protrusion is comprised of said first layer of foam rubber, wherein the outside surface portion of said at least one protrusion is comprised of said second layer of solid rubber, and wherein the protrusions are star shaped and the mat surface in the area surrounding the protrusions is ribbed or grooved to provide additional cleaning of a pedestrian's footwear.
Further, the protrusions are preferably arranged in a tire tread like arrangement or footprint with groups and rows of groups of protrusions.
The first rubber layer may be comprised of any standard rubber composition, including, but not limited to, acrylonitrile-butadiene rubber (NBR), styrene-butadiene rubber (SBR), carboxylated NBR, carboxylated SBR, chlorinated rubber, silicon-containing rubber, and the like, all of which must include a blowing agent to form the necessary closed-cell structure of the resultant foam rubber, such as in U.S. Pat. No. 5,305,565 to Nagahama et al. For cost purposes, the preferred rubbers are NBR, SBR, and blends thereof.
As noted above, the foam rubber component is important in this inventive floor mat. Dust control mats have exhibited general problems arising from frequent washings and harsh environments of use. First, the energy required to wash and dry a typical floor mat is significant due to the overall mass of the mats. The overall mass is most significantly attributed to the mass of the rubber within the mat. As will be appreciated, a reduction in the overall mass of the floor mat will result in a reduced energy requirement in washing and drying the mat. Moreover, a relative reduction in the mass of the rubber provides a substantial benefit. Thus, the utilization of a lighter weight rubber composition, such as foam rubber, in at least a portion of the dust control mat of the present invention includes a rubber backing sheet which may possess a specific gravity which is approximately 25 to 35 percent less then the rubber sheets of typical prior floor mats. Accordingly, a foam rubber is the bottom layer of the mat and the core layer of the integrated rubber protrusion(s) of this invention. Such a foam rubber layer is present as a thicker layer than the solid rubber cap (generally). The target thickness for such a first layer is from about 15 to about 500 mils, preferably from about 25 to about 400 mils, more preferably from about 40 to about 350 mils, and most preferably from about 75 to about 250 mils. The resultant lighter weight of the mat structure thus translates into a reduced possibility of the mat harming either the washing or drying machine in which the mat is cleaned, or the mat. being harmed itself during such rigorous procedures. Although the inventive floor mat must withstand the rigors of industrial machine washing, hand washing and any other manner of cleaning may also be utilized. Foam rubber also permits the retention or return to the original shape of the mat after continuous pedestrian use. Overall, the inventive floor mat provides an article which will retain its aesthetically pleasing characteristics over a long period of time and which thereby translates into reduced costs for the consumer.
The second rubber layer preferably comprises a solid rubber composition. Such a solid rubber may be comprised of any standard type of rubber, such as acrylonitrile-butadiene (NBR) or styrene-butadiene (SBR), or carboxylated derivatives of such butadienes, EPDM, and the like (i.e., those noted above but without the addition of a blowing agent), all merely as examples. Preferably, the second layer is comprised of NBR. The target thickness for such a second layer is from about 2 to about 50 mils, preferably from about 5 to about 40 mils, more preferably from about 10 to about 35 mils, and most preferably from about 15 to about 25 mils. This layer is preferably placed on top of the foam rubber first layer as to cover the entire first layer prior to vulcanization. However, this second layer may also merely cover a portion of the first layer, if desired. The first and second layers are calendered together, placed on the belt, and then a die mold is placed on top of the second layer which comprises openings through which molten rubber may flow during vulcanization and pressing of the structure. The high pressures (about 15 to about 50 psi, preferably 20 to 40 psi) and temperatures (about 250 to about 400° F., preferably from about 320 to about 385° F.) associated with vulcanization thus melt and force a certain amount of the two layers through the die mold openings. The denser solid rubber does not permit the less dense blown foam rubber to protrude through the solid rubber layer during this procedure. As such, the resultant protrusions possess foam rubber cores and solid rubber caps. Such protrusions add to the overall surface of the top of the mat structure, thus the solid rubber layer is appreciably thinner after vulcanization and molding than after the initial placement step. However, the solid rubber layer still remains intact and possesses sufficient strength to protect the foam rubber from contact with pedestrians' footwear, atmospheric conditions, and sunlight. The resultant mat thus is intended to be used with the protrusions facing toward the pedestrian. The inventive mat possess a two-layer structure with accompanying protrusions therein.
Furthermore, a significant problem exists within this field concerning the deterioration of the carbon—carbon double bonds in the matrix of the rubber backing sheet due to the exposure of the sheets to an oxidizing environment during use and cleaning. Specifically, the exposure of the mats to oxidizing agents during the washing and drying process tends to cleave the carbon-carbon double bonds of the rubber sheet thereby substantially embrittling the rubber which leads to cracking under the stress of use. In addition to the laundering process, the exposure of the mats to oxygen and ozone, either atmospheric or generated, during storage and use leads to cracking over time. The mat of the present invention may thus include an ozone-resistance additive, such as ethylene-propylene-diene monomer rubber (EPDM), as taught within U.S. Pat. No. 5,902,662, to Kerr, which provides enhanced protection to the rubber backing sheet against oxygen in order to substantially prolong the useful life of the mat. Such an additive also appears to provide a reduction in staining ability of such rubber backed mats upon contact with various surfaces, such as concrete, wood, and a handler's skin, just to name a few, as discussed in U.S. patent application Ser. No. 09/113,842 now U.S. Pat. No. 6,159,516 to Rockwell, Jr.
The term “integrated rubber protrusion” is intended to encompass any type of protrusion from the rubber mat sheet which is formed from the same rubber compositions of the required two separate layers of rubber and is not attached in any manner to the resultant backing sheet after vulcanization. Thus, such a protrusion would be produced through the melting of the rubber composition during vulcanization and allowing molten rubber to flow through a die mold in a position in which it remains until it cures and sets. As noted above, the majority of the mat structure (the first layer) is a rubber including a blowing agent (to produce a foam rubber) and a second layer of solid rubber covers this foam rubber portion. In such a manner, the protrusions are formed with a core of foam rubber and a cap of solid rubber upon vulcanization through a die-mold. The separate protrusions thus provide discrete areas of relaxed stress within the inventive mat (particularly with the core of softer foam rubber) which thus provides a cushioning effect to a pedestrian, greater than for an overall flat foam rubber structure.
With regard to the die, it may be constructed of any material which can withstand vulcanization temperatures (i.e., between about 250° F. and about 400° F.) and pressures (i.e., between about 15 psi and 50 psi, generally). Thus, any metal may be utilized, such as steel, aluminum, titanium, and the like. Preferably, the die is made of steel or aluminum, is generally square or rectangular in shape, and comprises holes throughout to ultimately form the desired protrusions. Preferably, such holes are multi-point star shaped with the same shape throughout the die from one surface to the other. The preferred procedure is outlined more particularly below.
The inventive mat provides a long-lasting, industrially washable, cushioned rubber floor mat which provides comfort to users as well as significantly increased duration of utility and continuity of aesthetic and modulus strength characteristics. All of this translates into reduced cost for the consumer as costs to produce are lower, the need to replace such mats is greatly reduced over other anti-fatigue, cushioned mat products, and possible medical and insurance costs may also be reduced with the utilization of such specific cushioned mats which also work to remove dirt and moisture from pedestrians' footwear.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic representation of a floor mat manufacturing machine and process.
FIG. 2 is an partial top view of a preferred embodiment of the inventive floor mat.
FIG. 3 is an partial bottom view of the preferred die.
FIG. 4 is a partial cross-sectional view along lines 4 — 4 of FIG. 2 .
FIG. 5 is a bottom or back view of the mat of FIGS. 1, 2 and 4 .
FIGS. 6-9 are respective schematic bottom view illustrations of dies or plates in accordance with other embodiments of the present invention.
FIGS. 10-12 are respective schematic enlarged top view illustrations of alternative protrusions in accordance with the present invention.
FIGS. 13-17 are respective schematic top view illustrations of die molds and corresponding floor mats in accordance with alternative embodiments of the present invention.
FIGS. 18-20 are respective photographic representations of particular examples of the present invention.
FIGS. 21-23 are schematic side view illustrations of a mat manufacturing process of the present invention.
DETAILED DESCRIPTION OF THE DRAWINGS
While the invention will be described in connection with certain preferred embodiments and practices, it is to be understood that it is not intended to in any way limit the invention to such embodiments and practices. On the contrary, it is intended to cover all alternatives, modifications and equivalents as may be included within the spirit and scope of the invention as defined by the appended claims.
Turning now to the drawings wherein like elements are designated by like reference numerals in the various views, FIG. 1 shows a floor mat manufacturing machine 10 and process for producing the inventive dust control mat 24 . The machine 10 comprises a conveyor belt 11 which carries the mat components 14 , 16 from an initial placement area 12 through a vulcanization chamber or press 22 . Thus, a calendered composite of the first layer of rubber (including a blowing agent) 14 and the second solid rubber layer 16 is placed on belt 11 . Next, a metal die or plate 18 is placed on top of layer 16 . The first rubber layer 14 has a thickness of about 90 mils and the second solid rubber layer 16 , being much thinner, has a thickness of about 15 mils. The resultant combination 20 , including the metal die 18 , is then moved into the vulcanization chamber 22 , which includes a heated press (not illustrated) to subject the mat components to a temperature of about 350° C. and a pressure of about 30 psi. After vulcanization, die 18 is removed from the mat 24 .
FIG. 2 gives a more detailed top view of the inventive mat 24 . The top cover for the mat 24 is the second solid rubber layer 16 (FIGS. 2 and 4 ). In an alternative embodiment, the second solid rubber layer may cover only a portion of the foam rubber layer ( 14 of FIGS. 1 and 4 ). The inventive mat 24 includes integrated star shaped rubber protrusions 26 which protrude from the mat 24 . These protrusions 26 provide the cushioning benefits as described more fully above for an anti-fatigue floor covering product.
Anti-fatigue mat 24 further includes a raised border or edge 28 . The surface of mat 24 between the protrusions 26 and the border 28 includes a plurality of crossing ridges or ribs 30 . The protrusions 26 are preferably taller or higher than the ribs 30 .
The preferred die 18 is more thoroughly depicted in FIG. 3 . The die is preferably about {fraction (1/10)}-2 inches tall, preferably {fraction (1/10)}-½ inch tall, and made of steel or aluminum. Any material may be used for this die 18 as long as it can withstand vulcanization temperatures and pressures without distorting its shape or permanently adhering to the mat product 24 of FIG. 1 (such as metals like steel, titanium, aluminum, and the like). The preferred die 18 comprises a plurality of cut-outs or openings 32 which are, again preferably, star shaped in configuration, having a diameter of about 0.1-1 inch, preferably about 0.1-0.5 inch and a depth of {fraction (1/10)}-2 inches, preferably {fraction (1/10)}-½ inch. It is through these holes 32 that the rubber composition of the first foam rubber layer ( 14 of FIG. 1) and the second solid rubber layer ( 16 of FIG. 1) are pressed to ultimately form the desired protrusions ( 26 of FIGS. 2 and 4) on the top side of the preferred mat ( 24 of FIG. 1 ).
The die 18 also includes a plurality of v-shaped grooves or recesses 34 which create the crossed ribs or ridges 30 of mat 24 . The ridges or ribs 30 may have a height of about 0.1 cm. Although the grooves 34 and ribs 30 are shown in a diamond crossing pattern, it is contemplated that other patterns 50 , 52 , 54 , 56 may be used as shown in FIGS. 6-9 of the drawings. Further, the ribs 30 can be instead recesses or grooves created by ribs or ridges on the bottom of die 18 . Also, although the protrusions 26 are shown to be multi-point star shaped, it is to be understood that the protrusions may be other star like shapes 60 , 62 , 64 as shown in FIGS. 10-12 of the drawings.
FIG. 4 shows a cross-section of a portion of the finished inventive floor mat 24 . Protrusions 26 have been formed comprising a foam rubber core 36 from the first rubber layer 14 and a cap 38 comprising the second solid rubber layer 16 . The resultant preferred star-shaped protrusions 26 are each about 0.1-1 inch, preferably 0.25 inch, in diameter and about {fraction (1/10)}-2 inches, preferably 0.12 inch, in height. The thickness of the solid rubber layer 16 after vulcanization has been reduced from about 15 mils to about 10 mils due to the associated pressures and the forcing of the rubber compositions 14 , 16 through the metal die ( 18 of FIGS. 1 and 3) during vulcanization.
With reference to FIG. 5 of the drawings, the back or lower surface 40 of the mat 24 preferably has a roughened, textured, dimpled, or textile like surface texture 42 . This enhances the anti-creep aspect of the mat 24 .
FIGS. 13-14 and 17 depict respective die molds or plates 100 , 200 and 500 , and FIGS. 15-16 depict respective floor mats 300 , 400 having preferred protrusion patterns 102 , 202 , 302 , 402 , 502 made up of groups 104 , 204 , 304 , 404 , 504 and rows 106 , 206 , 306 , 406 , 506 of groups of protrusion forming openings 108 , 208 , 508 , and protrusions 308 , 408 , respectively, which preferably have a star shape.
DETAILED DESCRIPTION OF THE INVENTION
As previously indicated, in the preferred embodiment of the present invention the base material for the first foam rubber layer is acrylonitrile-butadiene rubber (NBR) or styrene-butadiene rubber (SBR). Other materials which may also be used include, by way of example, hydrogenated NBR, carboxylated NBR, EPDM, and generally any other standard types of rubbers which may be formed in a foam state. As will be appreciated, the use of NBR or SBR is desirable from a cost perspective.
The present invention makes use of the addition of chemical blowing agents to the rubber materials ultimately yielding a lighter rubber sheet. Specifically, the rubber backing sheet of the present invention comprises either NBR or SBR or both mixed with a blowing agent. The rubber/blowing agent mixture is thereafter calendared as a solid sheet of unvulcanized. In practice, the raw NBR is believed to be available from Miles Inc. Rubber Division in Akron, Ohio. The SBR may be purchased from Goodyear Tire and Rubber Company in Akron, Ohio. EPDM may also be added in a preferred embodiment to provide ozone resistance and other properties.
In the preferred practice of the present invention, a masterbatch of the polymer components is first prepared by mixing the base rubber (either NBR or SBR) with the additive ozone resistant polymer (EPDM) in the desired ratio along with various stabilizers and processing agents. Exemplary compositions of the masterbatch for various additive ratios wherein EPDM is mixed with NBR are provided in Table 1A for ratios of NBR to the additive polymer of 9.0 (Column a), 2.3 (Column b) and 1.2 (Column c).
TABLE 1A
PARTS BY WEIGHT
MATERIAL
a
b
c
Rubber (NBR)
40
25
50
Additive Rubber (EPDM)
60
75
50
Plasticizer
10
5
15
Stabilizer
2
2
2
Processing Aid
1.75
1.75
1.75
Antioxidant
1.2
1.2
1.2
In the preferred practice the plasticizer which is used is diisononylphthalate. The stabilizer is trinonylphenolphosphate available from Uniroyal Chemical under the trade designation Polyguard. The processing aid is purchased from the R. T. Vanderbilt Company in Norwalk Conn. under the trade designation Vanfree AP-2. The antioxidant is purchased from Uniroyal Chemical under the trade designation Octamine.
Following the mixing of the masterbatch, curative agents are added in a second stage mixing process for formation of the raw rubber compound which forms the backing sheet of the floor covering article of the present invention. An exemplary composition of the raw rubber compound formed in this second stage mixing process is provided in Table 1B.
TABLE 1B
MATERIAL
PARTS BY WEIGHT
Masterbatch Blend
100
Sulfur
1.25
Stearic Acid
1
Carbon Black N-550
40
Vulkacit Thiaram MS (TMTM)
0.5
Zinc Oxide
5
Blowing Agent
2.5
Exemplary compositions of the masterbatch for various additive ratios of SBR to EPDM are provided in Table 2A in a manner similar to that of Table 1A.
TABLE 2A
PARTS BY WEIGHT
MATERIAL
a
b
c
Rubber (SBR)
40
25
50
Additive Polymer (EPDM)
60
75
50
Stearic Acid
1
1
1
Sunolite 240
2
2
2
Zinc Oxide
5
5
5
Carbon Black N-550
30
30
30
Carbon Black N-224
60
60
60
Calcium Carbonate
35
35
35
Talc
30
30
30
Supar 2280
80
80
80
After mixing of the SBR masterbatch, curative agents are preferably added in a second stage mixing process for formation of the raw rubber compound which forms the backing sheet of the floor covering article of the present invention. An exemplary composition of the raw rubber compound formed in this second stage mixing process is provided in Table 2B.
TABLE 2B
MATERIAL
PARTS BY WEIGHT
Masterbatch Blend
100
Sulfur
2
Methyl Zimate
1.25
Butyl Zimate
1.25
Dibutyl Thiurea
2.50
Tellurium Diethyldithiocarbanate
1
Blowing Agent
2.0
As previously indicated and shown above, the first foam rubber layer includes a blowing agent to effectuate the formation of closed gas cells in the rubber during vulcanization. The second solid rubber is thus preferably the same compositions as those listed above but without the addition of a blowing agent. Such a second layer is also preferably calendared to a thickness far thinner than for the first foam rubber layer in order to form the required solid rubber cap. The blowing agent for the first foam rubber layer is preferably a nitrogen compound organic type agent which is stable at normal storage and mixing temperatures but which undergoes controllable gas evolution at reasonably well defined decomposition temperatures. By way of example only and not limitation, blowing agents which may be used include: azodicarbonamide (Celogen AZ-type blowing agents) available from Uniroyal Chemical Inc. in Middlebury Conn. and modified azodicarbonamide available from Miles Chemical in Akron, Ohio under the trade designation Porofor ADC-K.
It has been found that the addition of such blowing agents at a level of between about 1 and about 5 parts by weight in the raw rubber composition yields a rubber sheet having an expansion factor of between about 50 and 200 percent. After the fluxing processes are completed, the uncured first rubber layer containing EPDM and the blowing agent are assembled with the second unvulcanized solid rubber layer placed over the first as previously described. A die, as previously described, is then placed over the second layer. The vulcanization of the two rubber layers is then at least partially effected within the press molding apparatus wherein the applied pressure is between 20 and 40 psi. Under the high temperatures and pressure, the nitrogen which is formed by the blowing agent partly dissolves in the rubber. Due to the high internal gas pressure, small closed gas cells are formed within the first rubber layer as the pressure is relieved upon exit from the press molding apparatus. In an alternative practice a post cure oven may be used to complete the vulcanization of the mat and provide additional stability to the resulting product.
EXAMPLE
Two separate rubber sheet materials are produced by fluxing together the materials as set forth in Table 1A in a standard rubber internal mixer at a temperature of about 280° F. to 300° F. for a period of one to two minutes. EPDM additions were made as shown in Table 1A to yield a ratio of EPDM to NBR of 3.0. Additions of curative agents as provided in Table 1B were then made for two separate rubber sheets, however, the second did not include the blowing agent. The first sheet, including the blowing agent, being an uncured sheet of the fluxed rubber compounds was then calendared to a thickness of about 90 mils, having a width of approximately 3 feet and a length of approximately 4 and-a-half feet. The second sheet, also being uncured, was then calendared to a thickness of about 15 mils and having the same dimension as the first sheet. The first sheet was then covered entirely on its surface with the second sheet. A die mold having a plurality of openings was then placed over the second sheet. The die mold/rubber sheets composite was then cured at a temperature of about 350° F. for fifteen (15) minutes under a pressure of about 40 psi and post-cured at a temperature of about 290° F. at atmospheric pressure for a period of five (5) minutes. The resultant floor mat possessed a border of solid rubber reinforcement around the perimeter of the structure as well as a middle section comprising a plurality of protrusions having a solid rubber cap over a foam rubber core. The first and second layers of rubber became permanently adhered together as well. The resultant mat article provided a significant amount of cushioning.
In accordance with alternative particular examples, the mats of the present invention have overall dimensions of, for example, about 25.6×35.4×0.2 inches (65×90×0.5 cm), 29.5×70.9×0.2 inches (75×180×0.5 cm), and the like. In each of these examples, each of the protrusions have an overall width of about 0.25 inches (0.63 cm) and a height of about 0.12 inches (0.3 cm).
While the invention has been described and disclosed in connection with certain preferred embodiments and procedures, these have by no means been intended to. limit the invention to such specific embodiments and procedures. Rather, the invention is intended to cover all such alternative embodiments, procedures, and modifications thereto as may fall within the true spirit and scope of the invention as defined and limited by the appended claims. | This invention relates to a cushioned dust control mat or article wherein the mat comprises at least two distinct layers of rubber, one comprising foam rubber, the other comprising solid rubber and has a plurality of star-shaped protrusions in the upper surface thereof. Also, the surface of the mat between the protrusions is ribbed or recessed. The solid rubber layer is present over the foam rubber layer on the top side of the mat in which the plurality of star shaped rubber protrusions are present to provide cushioning characteristics. The solid rubber layer acts as a cap or barrier for the foam rubber layer, particularly over the star shaped protrusions, in order to provide a mat which is resilient, will not easily degrade in its modulus strength after appreciable use and/or washing within industrial cleaning processes, and will not exhibit appreciable cracking or breaking, particularly within the star-shaped protrusions, after standard use for pedestrian traffic. A method of producing such an inventive cushioned floor mat is also provided. | 1 |
BACKGROUND OF THE INVENTION
Field of the Invention
This invention relates to showers, and more particularly relates to prefabricated shower tray and curbs for use in installing a shower pan.
Description of the Related Art
Shower pans used in the installation of showers in residential and commercial construction applications have been known in the art for decades. Shower pans slope inwardly and are required for proper water flow to a centrally-located drain. Most local building codes require shower pans.
Traditionally, mortar beds have been built on a subgrade for supporting the pan. Additionally or alternatively, shower frames have been constructed from wooden curbs and ramps to hold the pan. The components of the frame may abut one another but are not waterproof in the art. These curb-ramp assemblies server as little more than bases upon which other shower components forming the pan rest or are affixed, including mortar waterproofing membranes and tile.
Although there are shower substrates/frames fabricated from polymeric products known in the art which are supplied to contractors for improving the efficiency shower installation, these substrates suffer from many of the same defects and inefficiencies as mortar beds, including a propensity to leak, or seap, water through the bed/substrate components abutting one another into underlying wooden or steel members.
Traditional kits do not provide means of efficiently preventing leakage and provide no means of grading surfaces beyond the curb and tray abutment points. It is therefore desirable that a kit, tray or substrate assembly be provided with enhances waterproofing and pan installation.
SUMMARY OF THE INVENTION
From the foregoing discussion, it should be apparent that a need exists for a frameless polymeric shower implement for constructing a shower pan. Beneficially, such a apparatus would overcome many of the difficulties with prior art by providing a means for more efficiently waterproofing a shower pan.
The present invention has been developed in response to the present state of the art, and in particular, in response to the problems and needs in the art that have not yet been fully solved by currently available methods and apparati. Accordingly, the present invention has been developed to provide a shower pan installation kit comprising: a tray comprising one or more polymeric panels, each panel having a planar bottom surface and inwardly sloping graded top surface, wherein the tray defines a circular recess for receiving a drain; a polymeric curb having a planar inward surface and planar bottom surface; wherein the curb defines an upwardly rising groove recessed into the curb such that the groove rises from a lower point on the inward surface to a higher end point within the curb, the groove for subsequently receiving a waterproof membrane overlaying the tray; wherein an outer edge of the one or more polymeric panels rises through a distance from the panel's bottom surface to the top surface that is equal to a height of the lower point above the curb's bottom surface; and wherein the outer edge of the panel and inward edge of the curb abut one another.
The panels and curbing may be adhered one to another. The curb and paneling may be fabricated from polystrene. The curb and paneling may be fabricated from wood.
In some embodiments, the groove rises upwardly at between 10 degrees and 70 degrees off horizontal.
A second shower pan installation kit is also disclosed comprising: a tray comprising a polymeric panel having a planar bottom surface and inwardly sloping concave top surface, wherein the tray defines a circular recess for receiving a drain; a polymeric hexahedrial curb having a planar inward surface and planar bottom surface; wherein the curb defines an upwardly rising groove recessed into the curb such that the groove rises from a lower point on the inward surface to a higher end point within the curb, the groove for subsequently receiving a waterproof membrane overlaying and overlapping the tray; wherein an outer edge of the panel rises through a distance from the panel's bottom surface to the top surface that is equal to a height of the lower point of the curb above the curb's bottom surface; and wherein the outer edge of the panel and inward edge of the curb abut one another.
A method installing a shower pan during shower construction, the steps of the method comprising: recessing an upwardly rising groove into an inward surface of a hexahedrial curb; abutting the inward surface of the curb against an outer surface of a polymeric graded tray, such that a top surface of the tray sits flush with a bottom surface of the groove; overlaying and overlapping a waterproof membrane on the tray such that an overlapping portion of the waterproof membrane extends laterally into the groove defined by the curb; and constructing the shower pan above the tray and curb.
The method may further comprise adhering the tray to the curb. The method may further comprise constructing a mortar subsurface over the tray and curb.
These features and advantages of the present invention will become more fully apparent from the following description and appended claims, or may be learned by the practice of the invention as set forth hereinafter.
BRIEF DESCRIPTION OF THE DRAWINGS
In order that the advantages of the invention will be readily understood, a more particular description of the invention briefly described above will be rendered by reference to specific embodiments that are illustrated in the appended drawings. Understanding that these drawings depict only typical embodiments of the invention and are not therefore to be considered to be limiting of its scope, the invention will be described and explained with additional specificity and detail through the use of the accompanying drawings, in which:
FIG. 1 is a side elevational perspective environmental view of a shower pan installation kit in accordance with the present invention;
FIG. 2A is a side elevational perspective view of the curb of a shower pan installation kit in accordance with the present invention;
FIG. 2B is a side perspective view of a the curb of a shower pan installation kit in accordance with the present invention;
FIG. 3A is a side elevational perspective view of a panel of a shower pan installation kit in accordance with the present invention;
FIG. 3B is a side perspective view of a panel of a shower pan installation kit in accordance with the present invention;
FIG. 3C is an elevational perspective view of the tray of a shower pan installation kit in accordance with the present invention; and
FIG. 4 is a flow chart of the steps of a method for constructing a shower pan in accordance with the present invention.
DETAILED DESCRIPTION OF THE INVENTION
Reference throughout this specification to “one embodiment,” “an embodiment,” or similar language means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention. Thus, appearances of the phrases “in one embodiment,” “in an embodiment,” and similar language throughout this specification may, but do not necessarily, all refer to the same embodiment.
Furthermore, the described features, structures, or characteristics of the invention may be combined in any suitable manner in one or more embodiments. In the following description, numerous specific details are provided to provide a thorough understanding of embodiments of the invention. One skilled in the relevant art will recognize, however, that the invention may be practiced without one or more of the specific details, or with other methods, components, materials, and so forth. In other instances, well-known structures, materials, or operations are not shown or described in detail to avoid obscuring aspects of the invention.
FIG. 1 is a side elevational perspective environmental view of a shower pan installation kit 100 in accordance with the present invention. The shower pan kit comprises a curb 102 having an angled groove 104 upwardly rising from the curb's inner surface.
In various embodiments of the present invention, the curb 102 is cubic, cuboid or hexahedrial. The curb 102 has a planar bottom surface and a planar inner surface. In some embodiments of the present invention, the kit 100 comprises a plurality of curbs 102 sitting adjacent to and/or in line with one another.
In various embodiments of the present invention, the curb and/or panels 104 a - d are formed from polystyrene, wood, metal alloys, or other polymeric or elastomeric materials.
The curb 102 defines a recess, or groove 104 , rising upwardly from the inner surface through the curb 102 . This groove 104 is typically an angle-cut, largely planar recess carved or milled into the curb 102 such that the groove 104 rises from a predetermined height on the inner surface of the curb 102 at between 10 and 70 degrees of horizontal through the curb a predetermined distance.
The predetermined height of the groove 104 start point is predetermined to correspond to a thickness of the tray 106 and/or panels 108 a - c forming the tray.
The panels 108 a - c are typically formed, like the curb 102 , from elastomeric, polymeric or foam. The panels 108 a - c are lightweight and designed to be easily cut or adjusted to meet the needs of a shower installer or laborer.
The tray 106 , in some embodiments, is concave such that water runs toward the centrally located point in the tray 106 where a drain is disposed. In various embodiments of the present invention, the tray 106 is formed from a plurality of panels 108 a - c , each having a planar bottom surface that is not parallel to the panel's 108 top surface. The top surface of the panels 108 a - c may be graded, or declined toward the drain; or, in various embodiments, concave.
The height of the panels 108 a - c at their outermost edge is predetermined to correspond to the predetermined height of the groove 104 above the bottom surface of the curb 102 .
A panel 108 is position during installation such that it abuts, or sits adjacent to, the inner surface of the curb 102 . A waterproof membrane 112 is laid over the tray 106 such that is overlaps the tray 106 . The overlapping portion of the waterproof membrane 112 is inserted into the groove 104 of the curb 102 .
FIG. 2A is a side elevational perspective view of the curb of a shower curb 200 of a shower installation kit in accordance with the present invention. The curb 200 comprises a polystyrene curb 102 and defines an angled groove 104 . The curb 200 further comprises an upward surface 202 , an inward surface 204 , and an upward rise 206 .
The inward surface 204 is planar, as is a bottom surface of the curb 200 . In various embodiments, the groove 104 is sawed, carved, or cut into the curb 102 . The curb 102 may be fabricated from a mold as one integrated piece with the groove 104 defined.
In various embodiments, the groove 104 rises upwardly from the parallel to the bottom surface between 10 and 80 degrees off horizontal. The width of the groove 104 may vary from only a millimeter to seven or more centimeters. In some embodiments of the present invention, the groove 104 curves upward, and is convex in shape rather than linear.
The upward rise 206 is the distance between the bottom surface of the curb 102 and the beginning of the groove 104 . This distance is calculated to match or correspond to the thickness of a panel 108 or the tray 106 .
FIG. 2B is a side perspective view of a the curb of a shower pan installation kit in accordance with the present invention.
This figure further illustrates the same teachings shown in FIGS. 1-2A above.
FIG. 3A is a side elevational perspective view of a panel 300 of a shower pan installation kit in accordance with the present invention.
The panel 108 is presloped from a higher thickness to narrower thickness. In various embodiments of the present invention, the panel 108 is cut by installers to contour other panels 108 in the kit 100 , or irregular surfaces defining a shower. The panel 108 may be cut diagonally across both it lateral and longitudinal axes to coordinate with other panels 108 . In various embodiments, the panels 108 a - d are adhered together using means known to those of skill in the art. The panel 108 may circular, ovoid, or polygonal, and may be concave across its top surface to direct water to a centrally located point for a drain.
FIG. 3B is a side perspective view of a panel 320 of a shower pan installation kit in accordance with the present invention.
In various embodiments, the panels 108 and/or the tray come prefabricated with the membrane 112 and/or mortar and/or tile affixed to their top surfaces. The membrane 112 may be specially designed to bond to the curb 102 or an adhesive disposed within the groove 104 .
The panel 108 is presloped to decline from a thickness matching the upward rise 206 to a more diminished thickness.
FIG. 3C is an elevational perspective view of the tray 340 of a shower pan installation kit in accordance with the present invention. The tray 340 comprises four panels 108 a - d.
In the shown embodiment, the panels 108 a - d have been cut diagonally to fit together in x-shape. The panels 108 a - d have also been cut to define a recess for a drain. A membrane 112 is laid over the panels 108 a - d and the shower pan is built atop the tray 340 .
FIG. 4 is a flow chart of the steps of a method 400 for constructing a shower pan in accordance with the present invention.
The method begins 402 with an upwardly rising groove 104 being cut into a curb 102 at an incline. Next a panel 108 is abutted to the inward surface of the curb 102 such that the top outer surface of the panel 108 matches the upward rise 206 of the curb 102 .
A waterproof membrane 112 is laid 406 over the panel 108 such that all or a portion of the membrane 112 overlapping the panel 108 laterally is inserted into the groove 104 . The groove 104 receives the membrane 112 and the membrane 112 is adhered to the curb 102 within the groove 104 .
Finally, the shower pan is constructed 408 over the top of the panel 108 and the membrane 112 .
The present invention may be embodied in other specific forms without departing from its spirit or essential characteristics. The described embodiments are to be considered in all respects only as illustrative and not restrictive. The scope of the invention is, therefore, indicated by the appended claims rather than by the foregoing description. All changes which come within the meaning and range of equivalency of the claims are to be embraced within their scope. | A shower pan installation kit is disclosed comprising a hexahedrial polymeric curb and a tray having one or more graded or concave panels defining a recess for a drain. The inward surface of the curb is recessed inward and upward. This recess, or groove, is for receiving a waterproof membrane overlaid and overlapping the tray for improvement of the waterproof barrier underlaying the shower pan constructed above the kit. | 0 |
[0001] This invention relates generally to tracking user equipment in a long term evolution network and more particularly to efficient paging of user equipment.
BACKGROUND
[0002] A service area of a wireless telecommunications network is typically broken up into contiguous geographic regions called cells. In 4G networks, commonly known a long term evolution (LTE) networks, each cell is associated with an eNodeB (eNB), or base station and each cell is assigned to a tracking area. A cell is associated with a specific geographic service area and multiple cells can be associated with a specific tracking area. Also, an eNodeB may be associated with more than one cell. Consequently, a tracking area covers a geographic service area made up of the set of cells that are assigned to that tracking area. A mobility management entity (MME), similarly to an MSC in a 3G network, is responsible for managing the communications of UEs through a plurality of eNBs in one or more tracking areas.
[0003] As each UE moves through a geographic area, it transmits a tracking are update (TAU) request when it detects that it has entered a tracking area where it is not registered. The MME associated with the tracking area receives the TAU requests and maintains a record with information associated with the UE. When the MME receives a request to connect with a registered UE, the MME sends out a paging request to alert the UE that a connection is desired.
[0004] LTE providers have found that they need to increase the size of tracking areas in order to reduce the frequency of TAU procedures. In other words, if UEs change their tracking area less often, fewer TAU procedures will be using communication bandwidth. Unfortunately, while this increase in the size of tracking areas reduces the number of TAU procedures performed, it significantly increases the amount of paging traffic that must be handled by each eNodeB for connecting with individual UEs. Typically, the last seen eNodeB is part of the information the MME maintains for each UE and when a request to connect is received, the MME initially sends a paging request to this eNodeB. If the paging request fails, however, the MME then sends a paging request to all the eNodeBs within the same tracking area as the last seen eNodeB. If this paging request fails, a paging request can be sent out to all the eNBs in the same tracking area as well as one or more neighboring tracking areas. As the size of tracking areas increases, they encompass more eNodeBs and each eNodeB receives more paging requests.
[0005] Thus, a need exists for to support paging of more than a single eNodeB but less than a full Tracking Area. There is also a need to select a subset of eNodeBs to be paged where the UE is most likely to be present. The need for efficient paging is especially acute with regard to voice over internet protocol (VoIP) calls where a call will go to voice mail if a paging request isn't answered in a given amount of time.
SUMMARY
[0006] This section will be corrected when claims are finalized. The invention in one implementation encompasses a method and apparatus for improving paging in an LTE network. An MME maintains a small list of several last seen eNodeBs for each UE in the order in which they were visited, newest to oldest.
[0007] In one embodiment, there is provided a method, executed in a wireless network having base stations and wireless mobility managers controlling the base stations, which includes the steps of maintaining a Last Seen list of one or more base stations in the order in which they were visited by a user equipment (UE) for each UE attached to the wireless mobility managers, receiving a message requesting access to a requested UE, sending a first paging request to the base stations on the Last Seen list for the requested UE and if that paging request fails, sending a second paging request to a larger group of base stations.
[0008] In another embodiment, there is provided method of paging a user equipment (UE) using at least one mobility management entity (MME) operatively coupled to a plurality of eNodeBs (eNBs) in a LTE (Long Term Evolution) network, which includes the steps of maintaining a last seen eNB list of one or more eNBs in the order in which they were last seen by a user equipment for each UE attached to the MME, receiving a notification requesting access to a requested UE, sending a first paging request to the one or more eNBs on the last seen eNB list and if the first paging request fails, sending a second paging request to a larger group of eNBs.
[0009] Some embodiments of the above methods further include wherein the length of the list may be flexibly provisioned with the maximum number of eNBs to be paged.
[0010] Some embodiments of the above methods further include wherein the list of one or more eNBs is maintained so that it does not contain any duplicate entries.
[0011] Some embodiments of the above methods further include wherein the list is cleared when a UE reattaches to the wireless mobility managers.
[0012] Some embodiments of the above methods further include wherein a plurality of eNBs are grouped into tracking areas and a UE is capable of moving between eNBs within one tracking area, or between eNBs in different tracking areas.
[0013] Some embodiments of the above methods further include wherein the first and second paging requests are related to paging methods in a paging policy table, the method further including the steps of maintaining a paging policy table for the MME that determines which one or more paging methods are used in response to different types of notifications and accessing the paging policy table when a notification is received to determine how one or more paging methods to follow, said paging methods including any of accessing the last seen eNB, accessing a list of the last seen eNBs, accessing the last seen tracking area and accessing the last seen tracking area and neighboring tracking areas.
[0014] Some embodiments of the above methods further include the steps of maintaining a database of UE mobility patterns, said database storing the number of times one eNB is visited immediately after another eNB for pairs of eNBs within a set, generating a mobility patterns list, in response to the notification request, of likely eNBs the requested UE would visit by accessing the database with the requested UE's most recently visited eNB, and combining the last seen eNB list and the mobility pattern list into a final list for use in selecting eNBs to receive the first paging request for the requested UE.
[0015] Some embodiments of the above methods further include the step of accessing the database of UE mobility patterns with information indicating the last known direction of movement of the requested UE.
[0016] Some embodiments of the above methods further include wherein the database of UE mobility patterns is organized according to time of day and the step of generating a supplemental list further includes the step of accessing the database of UE mobility patterns to retrieve mobility data for the same time of day as the current time.
[0017] Some embodiments of the above methods further include wherein the paging method used for the first paging request can vary based on the type of notification.
[0018] In another embodiment, there is provided as apparatus for use in an LTE network for paging a user equipment (UE) using at least one mobility management entity (MME), said apparatus configured to perform the steps of maintaining a last seen eNB list of one or more eNBs in the order in which they were last seen by a user equipment for each UE attached to the MME, receiving a notification requesting access to a requested UE, sending a first paging request to the one or more eNBs on the last seen eNB list and if that paging request fails, sending a second paging request to a larger group of eNBs.
DESCRIPTION OF THE DRAWINGS
[0019] Features of example implementations of the invention will become apparent from the description, the claims, and the accompanying drawings in which:
[0020] FIG. 1 is a representation of one implementation of an apparatus that comprises that performs an efficient paging process.
[0021] FIG. 2 is a representation of on message flow for the paging procedure of the apparatus of FIG. 1 .
[0022] FIG. 3 is a representation of the mobility pattern data derived using the apparatus of FIG. 1 .
[0023] FIG. 4 is a representation of partial view of the geographic service area supported by the apparatus of FIG. 1 .
[0024] FIG. 5 is a flow chart depicting the operation of the apparatus of FIG. 1 .
DETAILED DESCRIPTION
[0025] A high level view of LTE network 100 is depicted in FIG. 1 . Network 100 is not a full LTE network but only depicts a few elements that may be used during paging of a wireless device that allows service on LTE network. Such a wireless device is known as a UE (user equipment) in LTE terminology.” At a basic level, an LTE network includes a plurality of eNodeBs (eNBs) 110 or base stations, which are responsible for handling communications with UEs in a certain geographic region. A representative UE is shown at 120 . The eNodeBs is associated with one or more cells, and each cell is assigned to a tracking area. A cell is associated with a specific geographic service area and multiple cells can be associated with a specific tracking area. Consequently, a tracking area covers a geographic service area made up of the set of cells that are assigned to that tracking area. In FIG. 1 , several eNodeBs 110 are shown grouped into tracking areas 115 and 125 . Since cells associated with different tracking areas may be assigned to a single eNodeB, it is also possible that an eNodeB 110 may appear in two different tracking areas. Also, the number of eNodeBs in each tracking area is just an example. Typically, tracking areas may include a flexible number of eNodeBs. Each eNodeB 110 may be communicatively coupled via a backhaul connection with a mobile management entity (MME) 130 and a serving gateway (SGW) 140 . The MME 130 and SGW 140 may be nodes in the network 100 or they may be physical computer components, such as a circuit board, that reside on a computer node in the network 100 . The functions of the MME 130 and serving gateway 135 as described herein may be implemented in hardware, firmware or software in combination with associated hardware. The MME 130 may perform UE paging operations and it may also perform interoperability functionality with 3GPP networks 140 . The SGW 135 may act as a mobility anchor during inter eNodeB handovers, provide interoperability communication with non-3GPP networks 150 and forward user data packets to various IP networks 145 .
[0026] As the UE 120 moves through the network 100 , the UE 120 may perform tracking area update procedures. That is, when the UE 120 detects that it is in a new tracking area, the UE 120 may send a tracking area update (TAU) request to the MME 130 to inform the MME 130 of the UE's 120 new location. If UE 120 is within tracking area 125 and transmits a tracking area update request, one of the eNodeBs 110 may receive the message, and forward the message to the MME 130 and the MME 130 may save the location of the UE 120 as within tracking area 120 . The MME also saves an ID of the eNodeB which forwarded the message. This is referred to as the “Last Seen eNodeB.” Whenever the UE 120 is attached to an LTE network—that is, the UE 120 has successfully registered with the MME 130 —the UE 120 transmits a TAU request when the UE 120 detects that it has entered a tracking area where it is not currently registered. Upon receipt of a TAU request, the MME 130 notes the tracking area and eNodeB where the UE 120 has registered. MME 130 also stores the eNodeB ID that is reported during other procedures such as Service Request and Handover.
[0027] FIG. 2 depicts the general message flow for a paging procedure. A DDN for a particular UE 120 is sent from a Packet Gateway (P-GW) 210 to a Signaling Gateway (S-GW) 220 when there is data available for UE 120 . This could comprise an incoming voice call, incoming text message, notification for a social networking app, etc. S-GW 130 forwards the DDN to MME 130 . Then MME 130 sends a paging request to the Last Seen eNodeB which is registered to UE 120 . If UE 120 is still in the cell served by eNodeB 110 , it receives the paging request and returns a service request to MME 130 . In response to the service request, MME 130 returns a DDN Acknowledge signal to S-GW 220 and transfer of the data proceeds.
[0028] If UE 120 has moved and is no longer served by the Last Seen eNodeB known to MME 130 , the UE will fail to respond to the initial page attempt and MME 130 will need to continue the paging process with additional page attempts. Typically, MME 130 will perform a series of page attempts as necessary, gradually expanding the size of the area in which the UE is paged. The set of eNodeBs where the UE is paged is a function of the paging method that has been specified for each page attempt within a Paging Policy table. As an example, when a paging request to the Last Seen eNodeB fails to reach UE 120 , the next policy in the Paging Policy table could require MME 130 to send the paging request to all eNodeBs 110 in the Last Seen Tracking Area. As another example, if this second paging attempt fails, MME 130 could move to a third paging process that sends the paging request to all eNodeBs in the Last Seen Tracking Area as well its neighboring tracking areas. This would result in a very large amount of paging traffic in the LTE network.
[0029] In a preferred embodiment, a new paging method called the Last Seen eNB List method is provided. For this method, the MME 130 maintains a small list of Last Seen eNodeBs which are paged instead of just the single Last Seen eNB. Allowing MME 130 to page more than one eNodeB 110 but less than all the eNodeBs in an entire tracking area allows MME 130 to reach UE 120 with relatively high effectiveness without generating an excessive amount of paging message traffic. As explained above, an MME can flexibly use a variety of paging methods to respond to a notification for accessing a UE. The specific sequence of paging methods is stored in the Paging Policy Table. It is also possible to adjust the Paging Policy Table based on the type of notification received. For some types, a single Last Seen eNB may be paged, followed by the Last Seen Tracking Area, then the Last Seen Tracking Area and its neighbors. It is also possible that MME 130 will use the Last Seen eNodeB List paging method in place of the Last Seen eNodeB paging method in cases where MME 130 needs to be more aggressive in its paging efforts (e.g., paging for incoming VoIP calls). The Paging Policy Table may be flexibly configured in a variety of ways, including the number of eNBs to maintain on the Last Seen eNB List.
[0030] For the Last Seen eNodeB List paging method, MME 130 constructs a list of eNodeBs 110 based on the UE 120 mobility history in terms of the eNodeBs that have served the UE. Paging this subset of eNodeBs is effective because UEs will frequently return to previously visited eNodeBs due to a variety of factors such as RF toggling and the high relative occurrence of “round trips” in movement patterns within a cellular network (i.e., cyclical movement).
[0031] The MME 130 shall track the mobility history of each UE by saving the following information:
a. The last seen eNodeB (i.e., the current eNodeB that was serving the UE during the last mobility-related procedure) b. The old last seen eNodeB (i.e., the eNodeB where the UE was observed prior to the last one) c. The older last seen eNodeB (i.e., the eNodeB where the UE was observed prior to the old last seen eNodeB)
[0035] Please note that MME 130 will manage this information to ensure that these values are unique. Duplicate values are not saved. Any old mobility history is cleared when the UE re-attaches to the LTE network or when UE 120 returns from another MME.
[0036] The Last Seen eNodeB List is generated using the collected mobility history. The length of Last Seen eNodeB List should be configurable. For example, if the maximum length of Last Seen eNodeB List is 1, then only the ‘last seen eNodeB’ will be included. If the maximum length of Last Seen eNodeB List is 3, then it may include the ‘last seen eNodeB’, the ‘old last seen eNodeB’, and the ‘older last seen eNodeB’. For larger maximum lengths, the list would be extended similarly.
[0037] In a further embodiment, MME 130 creates a Mobility Pattern List of eNodeBs that have a higher likelihood of successfully completing a paging request. This Mobility Pattern List can be combined with the Last Seen eNodeB List to create a list of a somewhat larger group of eNodeBs that is still smaller than the total number of eNodeBs in a tracking area. The Mobility Pattern List contains the set of eNodeBs that are the most likely next eNodeB to be visited based on the movement patterns for all UEs served by the MME 130 . While the Last Seen eNodeB List accounts for the high relative occurrence of “round trips” in movement patterns within a cellular network (i.e., cyclical movement), the Mobility Pattern List accounts for forward movement of a UE through a service area, i.e., linear movement such as moving along a highway or commuter rail line.
[0038] To generate the Mobility Pattern List, MME 130 analyzes the mobility patterns for UEs served by an eNodeB by tracking the number of times eNodeB ‘Y’ was visited when the ‘last seen eNodeB was eNodeB ‘X’. This information can be collected for an entire day or for specific periods of the day. This compiled data of mobility patterns can then be used to construct the top ranked ‘next likely’ eNodeB for predicting where the UE may have moved. An example of the data structure which could store the information regarding mobility patterns for a set of 8 eNodeBs is shown in FIG. 3 . This figure is a representation of the mobility pattern data derived using the apparatus of FIG. 1 and illustrates the relatively frequency of movement of UEs between specific eNodeBs. The full data set of mobility pattern data would cover all eNodeBs associated with the MME 130 and would include data from all UEs served by the MME 130 .
[0039] The Mobility Pattern List is generated using the top ranked ‘next likely’ eNodeBs for a UE based on its ‘last seen eNodeB’ value and mobility pattern data from the data structure of FIG. 3 . The length of the Mobility Pattern List should be configurable. For example, if the maximum length of the Mobility Pattern List is 1, then only the top ranked ‘next eNodeB’ will be included in the Mobility Pattern List. If the Mobility Pattern List length is 7, then the top 7 ‘next likely’ eNodeBs will be included. Inter-eNB mobility data would be collected for all eNBs served by the MME and could be generated using Per-Call Measurement Data (PCMD) collected by MME 130 .
[0040] An example of the generation of the Last Seen eNodeB List and the Supplemental List will now be described in conjunction with the data structure of FIG. 3 .
[0041] Assume the following parameter values for Predictive eNB Paging (are in use:
Max Last Seen eNodeB List Length=2 Max Supplemental List Length=4
[0044] Assume the UE's mobility history is as follows:
Last Seen eNB=1 Old Last Seen eNB=4 Older Last Seen eNB=6
[0048] Given this scenario, the sublists and final eNB paging lists would be as follows:
eNB Last Seen eNodeB List=1, 4 eNB Supplemental List=2, 4, 5, 7
[0051] A combination of the Last Seen eNodeB List and the Mobility Pattern List causes MME 130 to page eNBs 1, 2, 4, 5 and 7. Duplicates between the two lists will be eliminated. It should be noted that the Last Seen eNodeB List and the Mobility Pattern List can be used together or each can be used alone to accomplish an embodiment.
[0052] FIG. 4 depicts an arrangement of eNodeBs that further illustrates the example given above. Assume for example that a major road runs through the service areas of eNBs 7, 3, 1, 4 and 6. If the Last Seen eNodeB for a UE is eNB 1 in service area 410 , then the most likely eNBs for the UE to travel to next would be eNB4 in service area 420 , eNB2 in service area 430 , eNB7 in service area 440 and eNB5 in service area 450 . This configuration is shown in the mobility patterns in row 1 of the data structure of FIG. 3 . The inclusion of eNB5 in service area 450 could be due to the presence of an exit on the major road.
[0053] In another embodiment, the mobility patterns used to generate the Mobility Pattern List may take into consideration the last known direction of movement in addition to the last known position when processing data for the generation of the Mobility Pattern List. In other words, the top ‘next likely’ eNodeBs would be retrieved for the case where the last known position (i.e., last seen eNodeB) is ‘Y’ and the previous location before that (i.e., old last seen eNodeB) was ‘X’.
[0054] As a further embodiment, the Mobility Pattern List may be generated while taking into consideration the current time, thus utilizing only mobility history data when generating the Supplemental List that is from the current time of day (e.g., morning rush hour, evening rush hour, late night, etc).
[0055] An illustrative description of operation of the apparatus 100 is presented, for explanatory purposes in connection with FIG. 5 . As shown in step 510 , an MME maintains a Last Seen eNB List of one or more of the last seen eNBs for each UE attached to the MME. When the MME received a notification requesting access to a UE in step 520 , it sends a paging request to the Last Seen eNB in step 530 . If that paging request does not succeed in step 540 , a second paging request is sent to a larger group of eNBs, either all the eNBs in the Last Seen Tracking Area or all the eNBs in the Last Seen Tracking Area as well as adjacent tracking areas in step 550 . Once a paging request succeeds or the possible paging methods are exhausted, the paging process is completed in step 560 .
[0056] The apparatus 100 in one example comprises a plurality of components such as one or more of electronic components, hardware components, and computer software components. A number of such components can be combined or divided in the apparatus 100 . An example component of the apparatus 100 employs and/or comprises a set and/or series of computer instructions written in or implemented with any of a number of programming languages, as will be appreciated by those skilled in the art.
[0057] The steps or operations described herein are just for example. There may be many variations to these steps or operations without departing from the spirit of the invention. For instance, the steps may be performed in a differing order, or steps may be added, deleted, or modified.
[0058] Although example implementations of the invention have been depicted and described in detail herein, it will be apparent to those skilled in the relevant art that various modifications, additions, substitutions, and the like can be made without departing from the spirit of the invention and these are therefore considered to be within the scope of the invention as defined in the following claims. | A method and apparatus for efficient paging of user equipment (UE) in an LTE network is disclosed. In addition to storing the Last Seen eNodeB (LSeNB) for each UE attached to a mobility management entity (MME), the MME also maintains an LSeNB List of the eNodeBs seen immediately before the LSeNB for each UE. When a notification for a UE arrives at the MME, then MME can select from several paging methods, including paging only the LSeNB to locate the UE and sending a paging request LSeNB as well as to the list of eNodeBs seem immediately before the LSeNB. The MME can send a paging request to more than a single eNodeB but less than a full Tracking Area. Efficient paging is especially needed for voice over internet protocol (VoIP) calls where a call will go to voice mail if a page isn't answered quickly. | 7 |
This is a continuation of application Ser. No. 537,030, filed Dec. 27, 1974 now abandoned.
BACKGROUND OF THE INVENTION
This invention is directed to an improved hermetically sealed quartz crystal vibrator assembly and in particular to a mounting plate for mounting a flexural mode quartz crystal vibrator in a hermetically sealed vibrator assembly to render same particularly suitable for use in oscillator circuits adapted to produce high frequency time standard signals for electronic timepieces.
Heretofore, hermetically sealed flexural mode quartz crystal vibrator assemblies have taken on various forms, the most popular of which are the suspension of a tuning fork vibrator by suspension wires or the plating of electrodes on a quartz crystal vibrator plate, the plate being mounted to a reference member. Because of the difficulty in effectively mounting both types of vibrators to allow same to vibrate without being affected by shocks, etc., the time and expense required to manufacture such quartz crystal vibrator assemblies is less than completely satisfactory.
SUMMARY OF THE INVENTION
Generally speaking, in accordance with the invention, a mounting plate for a hermetically sealed flexural mode quartz crystal vibrator is provided. The flexural mode quartz crystal vibrator is adapted to vibrate in a first vibratory direction. A mounting plate having a first portion supporting the vibrator and a second portion secured to a reference member. The mounting plate further includes a resilient portion between the first and second portions, the resilient portion being adapted to vibrate in the first vibratory direction and to further vibrate in a vibratory direction defining an angle of about 90° with respect to the first vibratory direction. The resilient portion of the plate includes a stepwise bend to define a gap between the vibrator and the resilient portion of the plate overlapping the vibrator.
Accordingly, it is an object of this invention to provide an improved hermetically sealed quartz crystal vibrator assembly wherein the Q value remains stable in response to external shocks applied to the assembly.
Another object of this invention is to provide a hermetically sealed quartz crystal vibrator assembly having a resilient mounting plate for resiliently mounting a quartz crystal vibrator in a hermetically sealed assembly.
Still another object of this invention is to provide a flexible mounting plate which enables a hermetically sealed quartz crystal vibrator assembly to be reduced in size and the manufacturing thereof facilitated thereby.
Still another object of this invention is to provide a hermetically sealed quartz crystal vibrator assembly having a resilient lead plate for providing electrical connection between the vibrator electrodes and the hermetical terminals.
Still other objects and advantages of the invention will in part be obvious and will in part be apparent from the specification.
The invention accordingly comprises the features of construction, combination of elements and arrangement of parts which will be exemplified in the construction hereinafter set forth and the scope of the invention will be indicated in the claims.
BRIEF DESCRIPTION OF THE DRAWINGS
For a fuller understanding of the invention, reference is had to the following description taken in connection with the accompanying drawings in which:
FIGS. 1 and 2 are perspective views of hermetically sealed tuning fork vibrator assemblies constructed in accordance with the prior art;
FIG. 3 is a plan view of a hermetically sealed quartz crystal vibrator assembly constructed in accordance with the instant invention, with the top lid removed;
FIG. 4 is a sectional view of the hermetically sealed quartz crystal vibrator assembly illustrated in FIG. 3;
FIG. 5 is a perspective view of the tuning fork quartz crystal vibrator depicted in FIGS. 3 and 4;
FIG. 6 is a perspective view of a mounting plate constructed in accordance with the instant invention; and
FIG. 7 is a lead plate particularly adapted for use with the hermetically sealed quartz crystal vibrator assembly illustrated in FIGS. 3 and 4.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Reference is now made to FIG. 1 wherein a prior art hermetically sealed quartz crystal vibrator assembly of the type utilized in electronic timepiece oscillator circuits is depicted. The vibrator 1 is mounted to a hermetical terminal 4 by suspension wires 2 and 3, a dash line illustrating the packaging member. Such an assembly requires considerable time to manufacture because of the considerable skill required to mount the tuning fork vibrator and to obtain the desired frequency therefrom.
Reference is also made to FIG. 2 wherein another prior art hermetically sealed quartz crystal vibrator assembly is illustrated. A vibrator 5 is cut from a quartz crystal and is mounted to a hermetical terminal by a mounting base 6. Notches 7 are provided in the vibrator in order to minimize the vibratory effects of the vibrating portion of the vibrator 5 on the fixed portion of the vibrator mounted to mounting block 6. Nevertheless such notches cause the vibrator 5 to be physically impaired in response to shocks to the assembly. Also, like the prior art vibrator assembly illustrated in FIG. 1, the manufacturing of such an assembly is tedious, requiring many steps to form the electrodes on the surface of the vibrator and requiring considerable skill to provide a vibrator which is adapted to be tuned to vibrate at a desired frequency.
Reference is now made to FIGS. 3 through 6 wherein a hermetically sealed quartz crystal vibrator assembly constructed in accordance with the instant invention is depicted. A quartz crystal vibrator 8, more particularly illustrated in FIG. 5, is mounted to a metallic frame 20 by a mounting plate 11, the mounting plate 11 being more particularly illustrated in FIG. 6. The metallic frame 20 as is hereinafter discussed, in combination with lead wire 23 and a hermetical sealing member 19 effect a hermetical sealing terminal which in combination with lower lid 24 and upper lid 26 effects an airtight package for the quartz crystal vibrator. The vibrator's electrodes 10 are electrically coupled by a highly conductive extremely fine wire 18 to lead wire 23. Alternatively, a resilient lead plate 31, specifically illustrated in FIG. 7, could be utilized to effect the above noted electrical coupling in place of the wires 18. After the vibrator is regulated and mounted to the hermetical terminal, the lower lid 24 and the upper lid 26 are welded in a vacuum at their respective flange portions 25 and 27 to thereby provide a hermetically sealed quartz crystal vibrator assembly. A grounding pin 29 is utilized along with lead wire 23 to mechanically and electrically mount the hermetically sealed assembly in an oscillator circuit.
As is particularly illustrated in FIG. 5, vibrator 8 is formed of a sheet cut from a crystal pellet into the shape of a tuning fork. In a preferred embodiment, the vibrator would have a length C equal to 6.0 mm, a width A equal to 1.35 mm and a thickness B equal to 0.5 mm. The electrodes are preferably formed on the surface of the crystal plate by depositing Chromium and Gold on the surface and then removing same by a laser beam adapted to form the vibrator electrodes in a predetermined position. Such an electrode forming method makes it possible to obtain electrodes having a precise shape without causing any harmful effect to the quartz crystal and thereby improving the efficiency of the quartz crystal vibrator when compared with conventional electrode forming methods such as pealing off the Chromium and Gold deposited on the quartz crystal along certain dividing lines, the quartz crystal having first been shaved at the corners thereof, or having had applied thereto a paint prior to the deposition process. Further, after the Chromium and Gold are deposited on the surface of the vibrator, certain quantities of metallic or non-metallic mass elements 9 such as gold plating, solder or organic adhesives are added to the end portions of the tuning fork vibrator. The mass elements 9 effect a gradual regulation of the vibrator's frequency. A gradual removal of small amounts thereof by a laser beam, increases the frequency of the vibrator by an equally small amount, thereby providing for a fine adjustment of the frequency of the vibrator prior to hermetically sealing the package. Moreover, if the thickness B of the vibrator is equal to 1.5 mm or less, additional mass elements formed by gold plating, solder or organic adhesive are particularly effective in allowing fine adjustment of the frequency of the quartz crystal vibrator assembly.
Reference is now made to FIG. 6 wherein the mounting plate 11 which is adapted to support the vibrator 8 is more particularly illustrated. The mounting plate 11 is a flat plate formed of phosphorous bronze, berylium copper, spring steel or the like which enables the mounting plate 11 to vibrate in a direction parallel to the quartz crystal vibrator and in a direction at right angles with respect thereto. Such a mounting plate is manufactured by simple metal pressing techniques which allow same to be formed into the shape depicted in FIG. 6. If the weight of the vibrator to be mounted is considered, a vibrator such as the vibrator illustrated in FIG. 5 would require a mounting plate having a resilient portion with a width D equal to 0.2 mm and a thickness E equal to 0.15 mm, such a mounting plate allowing the vibrator to vibrate independently of any vibration or shocks received by the hermetically sealed package. Moreover, the vibratory or Q value of the assembly is maintained at high levels. Furthermore, when external shocks are applied to the vibrator, the resilient spring portion of the mounting plate vibrates in the parallel and right angle directions with respect to the vibrating direction of the vibrator thereby minimizing the shock effects thereto. Accordingly, if the shape of the mounting plate and the resiliency thereof are selected to protect the end portion of the vibrator from contacting the packaging lids and if projection 28 provides a vibration limiting device on the inside surface of the lid 26 for preventing contact of the vibrator with lid 26, the vibrator cannot be harmfully contacted by any element of the assembly and becomes shock resistant with respect to shocks applied to the assembly. The projection 28 can be formed by drawing in the surface of the upper lid or damping means can be mounted to the upper lid. Accordingly, the shape of the mounting plate 11 includes a stepwise or Z-shaped bent portion 14 which provides a gap between the vibrator plate 8 and the mounting plate 11. Because the shape of the mounting plate guarantees that the vibrator can be fixedly secured in the hermetically sealed package and cannot be harmed by shocks thereto, the mounting plate 11 is adapted to have a solder plating on the flat portion 13 to thereby mount the vibrator. Additionally, solder plating is provided on the lower surface of the mounting portion 17 of the mounting plate 11 to mount the mounting plate 11 to the metallic frame 20 of the the hermetical terminal. In order to effectively solder the vibrator to the flat portion 13 of the mounting plate 11, solder is placed on the Chromium and Gold portions deposited on the lower surface of the vibrator. Also, a mounting opening 15 is provided in the vibrator mounting portion 13 of the mounting plate 11, the opening effecting a strengthening of the manner in which the vibrator is fixed to the mounting plate.
It is noted, that since the mounting plate 11 effects an independent mounting of the vibrator to the hermetical terminal, the oscillating period of an oscillator utilizing such a hermetically sealed vibrator assembly is not affected by environmental changes such as drops in atmospheric pressure. Also, the mounting plate is adapted to be secured to the metallic frame 20, which includes annular projection 21 for securing the metallic frame to lower lid 24, and annular projection 22 for receiving mounting portion 17 thereabout.
Moreover, the flange surface formed by the metal frame annular projections define a thickness S, to thereby maintain the mounting plate 11 and vibrator 8 spaced from the upper lid 26 and lower closure member 24. Because the mounting plate 11 is mounted to the metal frame 20 by nesting the mounting portion 17 around annular projection 22 adapted to fit therein, the mounting plate is easily permanently fixed to the metallic frame. Since mounting portion 17 of the mounting plate covers the entire flange surface of the metallic frame, the stability of the vibrator is improved and furthermore, inclinations of the vibrator with respect to the package, as well as the failure to maintain the precise space therebetween can be avoided at all times. Moreover, mounting the vibrator to the mounting plate and then mounting the mounting plate 11 to the hermetical terminal provides an advantage in that no solder or organic adhesives need be placed on the vibrator but instead are utilized to mount the mounting plate to the metallic frame. It is noted that the electrodes formed on the surface of the vibrator and the lead wire of the hermetical terminals are electrically coupled by bonding the extremely fine wire 18, the only constraint being that a gap H be maintained at a greater distance than the minimum width which would cause contact between the wire and the lid 26 and hence short circuiting, or arcing therebetween. As noted above, the resilient lead plate 31 can be formed and utilized to replace the wires 18, such a plate being secured to the vibrator electrodes by means of solder or organic adhesives, and thereafter removing the portion P shown in phantom. Of course, a flat resilient securing plate would provide a more secure coupling, reduce the chances of arcing and would minimize chances of a wire breaking.
As depicted in FIGS. 3 and 4, the particular components of the quartz crystal vibrator assembly such as the vibrator 8, the mounting plate 11 and the hermetical terminal 19 are all contained in the hermetically sealed package formed by lower lid 24 and upper lid 26. Accordingly, the lower lid 24 and upper lid 26 are both formed from a thin material to thereby reduce the size of the vibrator assembly, the upper and lower lids have an oval shape as is clearly illustrated in FIG. 3, such members being formed by conventional pressing means. Both lids include peripheral flanges 25 and 27 to allow the lids to be hermetically secured by cold weld, soldering or other like techniques which allow a vacuum to be maintained in the package. Moreover, the grounding pin 29 is provided to eliminate any harmful electric fields caused by the welding and soldering. The sealed quartz crystal vibrator assembly is then mounted and electrically connected to an electric oscillator circuit by lead wire 23 of the hermetical terminal and ground pin 29 as noted above.
It is noted, that oscillator circuits utilizing a hermetically sealed quartz crystal vibrator constructed in accordance with this invention provide an extremely small-sized circuit particularly suited for use in an electronic timepiece. Moreover, because each component of the assembly can be mass produced by pressing machines, automatic lathes, etc., and further because the shapes are provided to allow same to be easily assembled, the cost of producing such an assembly is greatly lowered.
It will thus be seen that the objects set forth above, among those made apparent from the preceding description, are efficiently attained and, since certain changes may be made in the above construction without departing from the spirit and scope of the invention, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.
It is also to be understood that the following claims are intended to cover all of the generic and specific features of the invention herein described, and all statements of the scope of the invention which, as a matter of language, might be said to fall therebetween. | A hermetically sealed quartz crystal vibrator assembly having a flexible mounting plate for mounting a flexural mode quartz crystal vibrator adapted to vibrate in a first vibratory direction on a reference member. The mounting plate includes a first portion for supporting the vibrator and a second portion for coupling to the reference member. The mounting plate further includes a resilient portion between the first and second portions, the resilient portion being adapted to vibrate in the first vibratory direction and to further vibrate in a vibratory direction defining an angle of about 90° with respect to the first vibratory direction. The resilient portion of the plate includes a stepwise bend to thereby define a gap between the vibrator and the resilient portion of the mounting plate overlapping the vibrator. | 7 |
CROSS-REFERENCE TO RELATED APPLICATIONS
The present application claims the benefit of U.S. Provisional Patent Application 61/825,412, entitled, “Fully-Integrated Control System For Offshore Floating Wind Turbine Platforms”, filed on May 20, 2013. The contents of U.S. Provisional Patent Application 61/825,412 and U.S. Pat. No. 8,471,396, entitled “Column-stabilized offshore platform with water-entrapment plates and asymmetric mooring system for support of offshore wind turbines,” issued on Jun. 25, 2013, are hereby incorporated by reference.
BACKGROUND OF THE INVENTION
The present invention relates to offshore floating wind turbines. In particular, it presents a system and method for controlling floating wind turbine installations to minimize or reduce their heel angles.
BRIEF SUMMARY OF THE INVENTION
The disclosed subject matter relates to a machine-implemented method for controlling an inclination of a floating wind turbine platform that includes a generator, a set of turbine blades connected to a shaft inside a turbine nacelle, the turbine nacelle being mounted onto a tower, and at least three stabilizing columns to which the tower is mounted, where each of the at least three stabilizing columns have an internal volume for containing ballast. Position data measured in a defined frame of reference of the floating wind turbine is received at a processor. A heel angle in reference to the floating wind turbine platform is determined based on the position data. A first signal is sent from the processor for adjusting at least one of a blade pitch of the set of turbine blades and a torque of the generator based on the determined heel angle. A second signal is sent from the processor for distributing the ballast among the at least three stabilizing columns. The second signal for distributing the ballast is based on the determined heel angle and the first signal for adjusting the at least one of the blade pitch of the set of turbine blades and the torque of the generator.
The disclosed subject matter also relates to a non-transitory computer-readable medium comprising instructions stored therein. The instructions are for controlling an inclination of a floating wind turbine platform. The wind turbine platform includes a generator, a set of turbine blades connected to a shaft inside a turbine nacelle, the turbine nacelle being mounted onto a tower, and at least three stabilizing columns to which the tower is fastened. Each of the at least three stabilizing columns has an internal volume for containing ballast. The instructions, when executed by a system, cause the system to perform operations including receiving roll and pitch angle data in a defined frame of reference of the floating wind turbine. At least one of a blade pitch of the set of turbine blades and a torque of the generator is adjusted to alter an aerodynamic torque of the floating wind turbine platform, the adjusting being based on the received roll and pitch angle data. The ballast is distributed among the at least three stabilizing columns based on the adjusting of the at least one of the blade pitch of the set of turbine blades and the torque of the generator, and the received roll and pitch angle data.
According to various aspects of the subject technology, a system for controlling inclination of several floating wind turbine platforms, where each of the several wind turbine platforms includes a generator, a set of turbine blades connected to a shaft inside a turbine nacelle, the turbine nacelle being mounted onto a tower, and at least three stabilizing columns to which the tower is mounted, and each of the at least three stabilizing columns having an internal volume for containing ballast, is provided. The system includes one or more processors and a machine-readable medium. The machine-readable medium comprises instructions stored therein, which when executed by the system, cause the system to perform operations comprising receiving wind speed and direction data at one of the several floating wind turbine platforms. At least one of a blade pitch of the set of turbine blades and a torque of the generator is adjusted for each of the plurality of wind turbine platforms to alter an aerodynamic torque of the floating wind turbine platforms. The adjusting is based on the received wind speed and direction data. The ballast is distributed among the at least three stabilizing columns for each of the several turbine platforms. The distributing is based on the adjusting of the at least one of the blade pitch of the set of turbine blades and the torque of the generator, and the received wind speed and direction data.
In a specific embodiment, the floating wind turbine platform includes a floatation frame that includes the three stabilizing columns, and that supports the tower, the turbine nacelle, and the blades that rotate on top of the tower. Ballast water contained inside the stabilizing columns of the floatation frame can be pumped between stabilizing columns to keep the tower as vertically aligned as possible regardless of changes in wind speed or wind direction.
In order to create valuable synergies between the wind turbine and the floatation frame, this system and method are an improved version to the standard wind turbine controller in that it interacts directly with the controller of the ballast water pumps of the floatation frame, using additional measured signal inputs. This fully-integrated controller optimizes/improves the design life of the floatation frame and wind turbine tower by minimizing/reducing the platform heel angles while maximizing/maintaining good power production of the wind turbine.
BRIEF DESCRIPTION OF THE FIGURES
FIG. 1 shows a floating wind turbine platform with decoupled marine system and wind turbine controllers.
FIGS. 2 a and 2 b show example situations where the marine system controller turns on the appropriate pump to keep the tower vertical.
FIG. 3 shows a floating wind turbine platform with an integrated floating wind turbine controller.
FIG. 4 shows a flowchart for a marine system controller.
FIG. 5 shows a flowchart for standard variable torque controller for a wind turbine.
FIG. 6 shows a control diagram for a standard collective blade pitch controller for a wind turbine.
FIG. 7 shows a flowchart for an integrated controller with a modification of the standard torque control loop.
FIG. 8 shows a flowchart for an integrated controller with a modification of the standard blade pitch control loop.
FIG. 9 shows an example of a farm layout with wind sensors that allow ballast water pre-compensation.
FIG. 10 conceptually illustrates an example electronic system with which some implementations of the subject technology are implemented.
FIG. 11 shows a plot of wind speed versus power.
FIG. 12 shows a plot of wind speed versus thrust.
DETAILED DESCRIPTION
The detailed description set forth below is intended as a description of various configurations of the subject technology and is not intended to represent the only configurations in which the subject technology may be practiced. The appended drawings are incorporated herein and constitute a part of the detailed description. The detailed description includes specific details for the purpose of providing a thorough understanding of the subject technology. However, it will be clear and apparent to those skilled in the art that the subject technology is not limited to the specific details set forth herein and may be practiced without these specific details. In some instances, well-known structures and components are shown in block diagram form in order to avoid obscuring the concepts of the subject technology.
1. Identification and Significance of the Problem or Opportunity
Floating wind turbine technology is rapidly on its way towards commercialization. As of 2013, three full-scale prototypes with multi-megawatt turbines have been installed in the world, each using a different support platform type. The challenges associated with the design and operations of floating wind turbines are substantial. The floating platform, subject to wave and current loadings, bears a large weight (the wind turbine) and experiences large aerodynamic loads high above the water line. The large mass of the nacelle and rotor considerably raises the center of gravity of the platform compared to conventional floating structures, and the overturning moment created by the aerodynamic thrust at hub height is structurally penalizing.
The main challenge associated with floating wind turbines is the minimization or reduction of their motions to maintain optimal or good turbine performance, and minimize or reduce steel weight. A floating platform supporting a wind turbine will experience wind- and wave-induced motions.
In order to keep turbine performance at its best and to mitigate costs, the six degree-of-freedom motions have to be reduced or minimized as much as possible. The lateral motions of the platform—called surge and sway—are the most acceptable degrees of freedom. These planar motions mimic wind turbulence, and modify only the apparent wind speed on top of the tower.
The most unfavorable motions are the angular motions, rather the pitch and roll motions. These degrees-of-freedom result in high undesirable tower top motions and accelerations. If not restrained to acceptable limits, these motions and accelerations could considerably reduce the turbine performance, and reduce the structural life of the system. For example, considerable pitch or roll motions could modify the angle between the wind direction and the rotor plane, resulting in energy losses. The size and geometry of the floater matters the most for the platform dynamics. The stability of the floater is usually enhanced by its large size, the spacing between its water-piercing elements, and its large displacement. The designer is faced with a tradeoff between the stability and the size of the floater. It is desirable that the floater is both sufficiently stable and lightweight.
Another challenge lies in the adaptation of existing horizontal axis wind turbines (HAWTs). Typically, the turbine software, that is to say the system that carries the controller of the wind turbine, requires some modifications to accommodate peculiar floating wind turbine responses. Existing advanced control strategies are limited to use with onshore and fixed offshore wind turbines to achieve optimal or good power production while minimizing or reducing the loads on the turbine components.
The control objectives for floating wind turbines thus include the dampening of undesirable structural dynamic responses or the filtering of resonances due to natural wind turbulence or changes in wind speed and direction, and the maximization or improvement of power generation. Current control strategies for fixed wind turbines often involving the pitch angle of the turbine blades need to be re-engineered because the turbine is on a floating support. These active control system schemes must be adapted to floating wind turbines to limit wind-induced platform motions and mitigate coupling effects between floater and turbine.
A feature of the invention is aimed at creating a single controller for floating wind turbine platforms in order to meet the challenges described herein. This novel integrated controller minimizes or reduces the overall low-frequency angular response of the support platform.
Thus, the designer of the system can reduce the amount of construction material required for the floatation frame and the wind turbine components, and still target the same platform design life (mostly for fatigue-inducing cyclic loads), which would make its technology more economical and prone to reach unsubsidized market competitiveness.
2. Technical Approach for the Invention
In a specific implementation, a feature of the invention is based on the interaction of two existing controllers: the marine system controller of the support platform and the modified wind turbine controller. Each controller is described on its own first, and the integration of the two controllers, the subject of this invention, is then described in detail.
A. Marine System Controller
As presented in U.S. patent application Ser. No. 12/988,121, the marine system controller controls ballast water contained inside the three columns of the floatation frame that can be moved from columns to columns in order to maintain the low-frequency platform angular motions to zero or the wind tower vertical. This is a closed loop system, so the designer of the system fixes the necessary total amount of water based on the maximum overturning moment due to the maximum wind turbine thrust force.
FIG. 1 shows a floating wind turbine platform 100 with decoupled marine system 105 and wind turbine controllers 110 . For more redundancy and for a more efficient system, two pumps can be installed at each of the first column 115 , second column 120 , and third column 125 , which would bring the total number of pumps for the system to six pumps ( 130 , 135 , 140 , 145 , 150 , and 155 ). Each of the six pumps transfers ballast 160 from the column at which the pump resides to the column to which the pump is connected.
For example, the first column 115 has two pumps: pump 130 and pump 135 . The pumps work on an on-and-off basis. They are switched on only occasionally, when the wind speed or direction changes significantly. The controller is optimally set to turn on the pumps on average a few times per day, despite considerable dynamics due to wind and wave disturbance, in order to avoid pump fatigue and excessive energy expenditures on the platform.
The platform is fitted with motion sensors 160 to measure the platform angular motions that can be used as input signals for the marine system controller. Accelerometers or inclinometers are composed of a simple moving mass mounted on springs that track gravity. They both sense the acceleration due to the rotation of the platform, but also due to the linear accelerations—in surge, sway, and heave.
As far as this marine system controller is concerned, both a bi-axial pitch- and roll-inclinometer or a bi-axial surge- and sway-accelerometer are acceptable since linear accelerations (surge and sway) can be transformed to angular motions (pitch and roll). Both sensors are acceptable so long they track the gravity component of the platform, which is similar to the low-frequency angular motions. These motions sensors can be installed at any location on the platform. Usually for redundancy again, several motion sensors are installed in different columns and their measurement outputs are compared at all times before being fed into the control loop.
FIGS. 2 a and 2 b show example situations where the marine system controller turns on the appropriate pump to keep the tower vertical. (See, e.g., U.S. patent application Ser. No. 12/988,121 entitled “Column-stabilized offshore platform with water-entrapment plates and asymmetric mooring system for support of offshore wind turbines”).
FIG. 2 a shows a sudden change in wind speed will create a thrust force that will tend to cause the floating wind turbine platform 105 to lean away from the wind direction. If the wind is coming from between column 102 onto column 103 , in the direction as shown in FIG. 2 a , the torque caused by the wind will tend to push the downwind column 102 into the water and lift the upwind column 103 out of the water. As the wind speed and direction change, the wind turbine may utilize an internal active ballast system to transfer ballast 191 from one column to another in order to counteract the wind induced forces and moments and keep the structure 105 at the design floatation water line.
FIG. 2 b shows an example of a change of wind direction. The active ballasting system will adjust the water in the columns 102 , 103 when the wind has shifted. With reference to FIG. 2 b , the floating wind turbine platform 105 is illustrated with the wind blowing at a 90-degree shift from the platform centerline wind direction, with the wind coming over the left side of the platform 105 . The active ballast system has moved water from the right side column tank 191 to the left column tank 191 and the platform 105 is substantially horizontal. When the wind velocity drops and platform 105 has changed in its heel angle, the alignment sensor detects the list angle of the platform 105 and the controller instructs the pumps to move water 191 from the left column tank to the right column tank. The active ballast system moves water from the left column tank to increase the buoyancy and adds more water to the right column tank to increase the weight of the column. Platform 105 is again horizontal and the pumps have stopped until the inclination sensor detects another change in the platform inclination.
FIG. 4 shows a flowchart for a marine system controller, including the logic behind the feedback controller. The platform roll and pitch angles, α and γ, are input signals to the controller at 405 , provided by the platform sensors. Firstly, the measured signals are low-pass filtered at 420 to cancel off all the high-frequency disturbances resulting from the wave and wind dynamic and stochastic effects. The platform roll and pitch angles are low-pass filtered using standard low-pass filtering strategies such as high-order Butterworth filters. Based on the filtered platform pitch and roll angles, α and γ , the relative angles θ i-j between column top centers i and j, are derived using the following equations:
{
θ
1
-
2
=
-
(
3
2
γ
_
+
1
2
α
_
)
θ
1
-
3
=
-
(
3
2
γ
_
+
1
2
α
_
)
θ
2
-
3
=
α
_
(
1
)
The following convention is used. If θ i-j is positive, it means that column i is higher than column j. The error e i-j =|θ set −θ i-j | is the error used as an input of the controller. Usually, θ set =0°. Based on the sign of θ i-j , the correct pump P i-j will be turned on at 410 provided that e i-j is greater than a certain value that defines the dead-band for ON. The pumps P i-j or will be switched off provided that e i-j is less than a certain value that defines the dead-band for OFF. Depending on the relative angles θ i-j , one, two, or three pumps will be on. With this algorithm based on the relative angles between column top centers, the fastest water transfer path is always considered, thus the platform is always back to even keel very quickly or as fast as possible in every situation. Automatic bypass is also functioning with that approach, if one pump is suddenly deficient. The platform dynamics are measured, including its roll and pitch angles, α and γ, at 415 and used to provide a heel angle measurement fed back into the feedback loop.
A standard Proportional-Integral-Derivative (PID) controller could also be used in the determination of based on the heel angle error, but a simple on-off controller preceded by a filtered signal can be sufficient, due to the high capacitance of the system.
B. Conventional Wind Turbine Controller
The wind turbine controller includes a number of instruments, a number of actuators, and a computer system (or a microprocessor)—able to process the signals input by the instruments and communicate these signals to the actuators. The main objective of the wind turbine controller is the maximization or generation of the power production and the minimization or reduction of the extreme and cyclic loads on the wind turbine components.
Two types of control are usually performed by the system. The supervisory control allows the turbine to go from one operational state to the other. Examples of operational states are start-up, power production, normal shutdown, emergency shutdown, standby, and so forth.
The second type of control performed by a wind turbine is called closed-loop control and occurs at a given operational state of the turbine to keep the turbine at some defined characteristic or operational boundary for that state.
The wind turbine thrust force F T , the aerodynamic torque T r , and the power P r vary according to:
{
F
T
=
1
2
ρ
AC
T
(
λ
,
β
)
V
2
T
r
=
1
2
ρ
ARC
q
(
λ
,
β
)
V
2
P
r
=
1
2
ρ
AC
p
(
λ
,
β
)
V
3
(
2
)
Where ρ is the density of air, R is the rotor radius, A=πR 2 is the rotor swept area, V is the wind speed, C T is the thrust coefficient, C q is the torque coefficient, and C p is the power coefficient. All the non-dimensional coefficients (C T , C q , and Cp) depend on two parameters, the speed-tip ratio λ, and the blade pitch angle β. The speed-tip ratio is the ratio of the angular speed of the rotor ω at the tip of the blade over the wind speed V.
Typically, in power production mode, depending on the wind speed, two control regions called partial load and full load require different control strategies. These control regions are presented in FIGS. 11 and 12 . FIG. 11 is a plot of wind speed versus power in the partial load and full load regions. FIG. 12 is a plot of wind speed versus thrust in the partial load and full load regions.
In partial load, when the wind speed is below the rated wind speed—the lowest wind speed at which the turbine produces the maximum power—the controller will vary the generator torque to maximize the aerodynamic power capture, while keeping the blade pitch angle β at its optimal setting (usually zero degree).
Basically, the generator torque can be controlled to any desired value, which is proportional to the square of the filtered generator speed, with the aim of varying the rotor rotational speed to maintain a constant and optimal tip-speed ratio λ.
FIG. 5 shows a flowchart for standard variable torque controller for a wind turbine. The aerodynamic torque T R is an input to the controller, and will always try to be matched by the generator torque T G command, based on the actual rotor velocity ω. The rotor inertia J 505 , and an integrator block 510 come into play to represent the dynamic of the system described by the following equation:
T R −T G =J{dot over (ω)}
In full load, or above rated wind speed, the power produced is close to the rated power, but the turbine must limit or reduce the aerodynamic power extraction (or the Cp coefficient) so as not to exceed turbine component design loads, such as the generator. This time, the rotor spins at a constant angular speed ω, so the only parameter that can reduce the power coefficient Cp is the blade pitch angle β.
The generator torque is also held constant at the rated torque, but could also be controlled. The additional aerodynamic power that could be extracted is thus shed by varying the blade pitch angle. An increase in blade pitch angle—when the leading edge of the blade is turned into the wind—diminishes the aerodynamic torque by decreasing the angle of attack, hence the lift on the blades. Here, conventional PI or PID control strategies are used to modify the blade pitch angle, based on the generator speed error between the filtered generator speed and the rated generator speed. In some cases, notch filters are used to prevent excessive controller actions at the natural frequency of certain turbine components, such as the drivetrain torsional frequency or the blade passing frequency.
FIG. 6 shows a control diagram for a standard collective blade pitch controller for a wind turbine. The rotor velocity ω is measured, properly filtered and processed by 620 , and compared to its setpoint ω ref (the rotor velocity at rated power), which creates an error signal. This rotor speed error signal is fed into a PI controller 605 to compute the pitch command sent to the blade pitch actuator 610 . The wind turbine 615 continues to operate as the blade pitch angles are being controlled.
During a turbine startup, the PI controller 605 sends a command to the blade pitch actuator 610 to pitch the blades from feather (90 degrees) to the run position and let the wind accelerate the rotor until a certain speed is reached. The generator is then engaged and the wind turbine 615 starts producing power.
Similarly, for a normal turbine shutdown, the blades are pitched from their run position to feather. The generator is disengaged, when the turbine slows enough to drop the power to zero.
C. Integrated Controller
During power production, sudden variations of wind speed or directions can occur quite often at the site of floating wind turbines. These variations directly impact the overall magnitude and direction of the thrust force of the turbine applied to the rotor disk area in the direction of the wind. Viewed from the supporting platform far below the wind turbine hub, the thrust force represents an overturning moment to be withstood, and can yield high platform heel angles. Even if temporary, these high heel angles are detrimental to the overall system design life, and should be minimized during the unit lifetime.
In a specific embodiment, a feature of the invention includes an integrated controller that controls the wind turbine and the ballast pump simultaneously, in order to maintain the platform heel angle below a certain limit at all times or as desired. This controller is an extension of conventional wind turbine controllers in that it is modified to interact directly with the ballast pumps to minimize the heel angles of the floatation frame. The main benefit brought by this invention is a rise in the structural design life of the floatation frame if the same amount of construction material (most of the case, it is steel) is used, without sacrificing the overall power output of the turbine.
Based on industry experience, heel angles of up to 15 degrees could be reached by a floating wind turbine platform when the maximum thrust of the wind turbine is applied at the hub height. If the two controllers are decoupled, as described in the first two paragraph of this section, the platform marine system controller works independently of the wind turbine. A simple signal can be shared between the two controllers to shut down the turbine if a fault occurs on the platform.
If the two control systems are completely decoupled, the platform will experience high heel angles in sudden shifts of wind speed or direction. The reason lies behind the difference in time constants for the two control systems. The turbine controller usually acts very quickly on the scale of a second, since it is designed to adapt to the quick disturbances of wind speed due to turbulence. The marine system controller is working on a timeframe of about ten minutes, because of the time necessary to pump water from one column to another.
For example, if the wind shifts from the cut-in wind speed to the rated wind speed in a matter of minutes, an extreme heel angle of about 15 degrees could be experienced by the floating platform, until the marine system controller triggers the appropriate ballast pumps to bring the platform back to even keel. At this high heel angle, the power output of the turbine would be reduced by the cosine of the heel angle of 15 degrees, since the rotor swept area is reduced.
Thus, a platform high heel angle results in some loss in turbine power output. So, the marine system controller, even if used independently of the turbine controller, presents the benefit of keeping the tower vertical most of the time, but high heel angles are still experienced during transients (such as turbine startups or shutdowns) or sudden shifts of wind speed or wind direction.
FIG. 3 shows a floating wind turbine platform 300 with an integrated floating wind turbine controller 305 . In a specific embodiment of this invention, the wind turbine controller 305 directly controls the platform pumps ( 330 , 335 , 340 , 345 , 350 , and 355 ), in order to remedy the issues presented by two decoupled controllers. The platform pitch and roll angle information obtained by motion sensors 360 can be used directly by the turbine controller to keep the platform heel angle below a certain limit, say 5 degrees, at all times or as desired.
The wind turbine controller 305 would control either the generator torque or the blade pitch angle (or both at the same time) to temporarily maintain the thrust of the turbine 310 at a lower level, while water is being pumped from between the three columns ( 315 , 320 , and 325 ). In other words, the change of thrust loading on the turbine 310 resulting in an overturning moment will match or correspond to the change of righting moment due to the ballast water.
During that transition period—when the water 360 is being pumped from column to column—the overall thrust and power output of the turbine could be lower, but the platform heel angle would also be lower (below 5 degrees), which would actually keep the power production higher, than if the platform heel angle was 15 degrees.
There is clearly a tradeoff between the platform maximum allowable heel angle and the power production. If the heel angle is kept too low, the change in thrust will be very small while water is being pumped, leading to a lower power output than if the ballast pumps were started after the change in thrust. If the heel angle is kept too high, the power output loss originates from the cosine term. In other words, an optimal point can be found at which the power production would be maximized at all times or sufficiently high, while the low-frequency platform heel angle would be kept low, leading to an increase in the design life of the platform (mostly cyclic loads due to the weight of the rotor nacelle assembly in high heel angles).
However, in many cases, the main benefit of this system is truly the reduced amount of construction material for the platform, such as steel, which will improve the cost-effectiveness of floating wind turbine technologies.
In a specific implementation, this novel integrated controller entails the modification of a conventional wind turbine controller to control the aerodynamic torque (or thrust force) of the wind turbine while allowing the activation of appropriate ballast water pumps.
Equation (2) suggests that the thrust and the aerodynamic torque can be reduced if either the tip-speed ratio λ, or the blade pitch β are modified (or both at the same time). Therefore, these two parameters can be changed by the controller in partial load and in full load to maintain an aerodynamic torque that would minimize or reduce the platform heel angle.
At this stage, several options are considered depending on the operational state and the region of control for the wind turbine. The platform heel angle h would be a combination of roll and pitch and is defined as the squares root of the sum of the roll and pitch angles squared:
h =√{square root over (α 2 +γ 2 )} (3)
i. Approach in Power Production
In a specific implementation, in a first form, the generator torque demand could be adjusted to modify the tip-speed ratio λ or the rotor speed, in order to reduce the aerodynamic thrust when the platform heel exceeds a certain set point. The appropriate pumps could then be started up by the control system, and the torque demand would be constantly adjusted, until the pumps are turned off, and normal operation can restart.
During that transition period, the generator torque would be partially controlled based on the platform heel angles measured from the inclinometers or accelerometers. The conventional wind component of the generator torque is obtained through a direct measurement and low-pass filtering of the rotor velocity. With this strategy in mind, the torque of the turbine would be derived as a sum of two terms, one due to the platform heel, and one due to wind-induced conventional rotor velocity.
If the platform reaches a heel angle greater than a given set point (for example 5 degrees), this new control loop is called by the system. Automatically, the right pumps are switched on, while the desired torque would be calculated slightly differently to temporarily reduce the rotor aerodynamic torque (or thrust). This control loop comprises two branches.
FIG. 7 shows a flowchart for an integrated controller with a modification of the standard torque control loop. The first branch is the branch already used on conventional variable speed controllers, as shown in FIG. 5 . The generator speed is first used as an input, low-pass filtered, and the generator torque is determined based on a formula or lookup table. Usually, the generator torque is directly proportional to the filtered rotor velocity squared.
The second branch of the control loop (as described with reference to FIG. 4 ) uses the platform roll and pitch angles as input signals, calculates the heel angle of the platform in the frame of reference of the nacelle turned into the wind, low-pass filters this heel angle, and finally computes the second component of the desired torque using a PID controller 705 based on the platform heel angle error.
FIG. 8 shows a flowchart for an integrated controller with a modification of the standard blade pitch control loop. In a second form, the torque is still determined in a conventional way, as shown in FIG. 6 , so that the most optimal rotor speed is met, but the blade pitch angle is modified to control the aerodynamic torque. The blade pitch command is computed based on the sum of the typical filtered rotor speed error component calculated with a PID controller 805 , and a second component based on the platform heel angle error calculated again with a PID controller 805 . The new pitch command is the sum of these two components, only if the platform error exceeds a certain heel angle (for example 5 degrees). In that case again, the controller presents a control loop with two branches, one branch dealing with the component based on the filtered rotor speed error, the other branch taking care of the other component based on the filtered platform heel angle error.
In a specific implementation, a combination of these two forms of control is provided for both regions of turbine operation, in partial load and in full load. The modification of both the generator torque 810 and the blade pitch angle in both regions would add flexibility in the control system, regardless of the control region. For certain types of turbine, it is already not atypical to see the blade pitch angle being controlled below rated wind speed, and the generator torque being controlled above rated wind speed.
Thus, on the same principle, the generator torque controller in the first form and the blade pitch controller in the second form could be combined to temporarily control the aerodynamic torque, while the water is being shifted from column to column. The combination of both strategies would improve the overall performance of this integrated controller.
ii. Approach for Gentle Turbine Startups and Shutdowns
Gentle startup and shutdowns procedures are definitively desirable, as they can be intense fatigue life drainers for the turbine and the floatation frame. In a specific embodiment, a feature of the invention also relates to a controller that is used in the case of startup and shutdowns on the same principles as the ones described in operation.
In the case of a startup, the blade pitch is controlled to go from feather-to-pitch at the same speed as the ballast water is moved from column to column, so that the heel angle of the platform remains low at all times during the procedure. In the case of a shutdown, the blades would be controlled to go from pitch-to-feather while allowing the ballast water to maintain the platform even keel, until the turbine is stopped.
In both cases, the filtered platform heel angle error could be used as an input to an extra branch in the control loop to calculate the blade pitch at all times. As a result, the blade pitch increase or decrease is much slower than in the case of a conventional controller. Similarly, the generator torque ramp-up or ramp-down time could be increased to match the required ballasting time, in order to minimize or reduce the platform heel angle at all times or as desired during startup and shutdowns. Again, a combination of blade pitch and torque control can be used simultaneously to produce the same intended results.
D. Other Versions of the Integrated Controller
i. For a Single Floating Wind Turbine: Pre-Compensation
In another form, the wind turbine system controller could anticipate a change in wind speed or direction that would trigger an imminent startup or shutdown of the turbine, and pre-transfer water from column to column before any turbine action is performed. For instance, in the case of a turbine shutdown, the platform would be pre-inclined while the turbine is still spinning, so that half of the water ballast transfer is done upfront. The turbine would then be shut down, and the ballast water would continue to be transferred between columns until the platform is even keel. This ballast water pre-compensation scheme would halve the maximum platform heel angle.
In that case, the controller could use two extra input signals: an estimate of the mean wind speed and wind direction. A pre-compensation algorithm would be applied to pre-adjust the amount of ballast water in the different columns. Instruments such as anemometers or Light Detection and Ranging or Laser Imaging Detection and Ranging (LIDAR) sensors can be installed for that purpose.
This strategy leads to two possibilities: it could be a complementary approach to refine the first integrated controller described in the previous section (more information comes from the wind measurements), or it could be a much simpler integrated controller decoupled with existing wind turbine control schemes (variable torque and pitch controllers), and therefore could be implemented in a much easier fashion.
This control strategy could be employed in power production as well, when the wind turbine detects any significant change in wind speed and direction. Ballast water could be pre-adjusted in the platform columns, so that the maximum heel angle experienced by the platform in any situation would be reduced by a factor of two. At all times or as desired, the amount of water in the different columns can be determined based on the thrust force of the turbine and its applied direction, so based on the wind speed and the wind direction. Based on this information, a look-up table could be derived, and the wind turbine controller would follow that table to pre-adjust the ballast water of the platform as desired such as every time the measured heel angle exceeds a given reference heel angle (say again 5 degrees).
ii. For a Floating Wind Turbine Farm
FIG. 9 shows an example of a farm layout with wind sensors that allow ballast water pre-compensation. In the case of a farm of floating wind turbines 905 , previously described integrated control strategies can be implemented, and external input signals can also be used to refine the overall control scheme. Indeed, wind speed and direction measurement sensors can be installed a few miles away in different directions around the farm to predict any sudden change in wind speed or direction. The floating wind turbine farm is fitted with a few wind measurement sensors 910 such as LIDARS at different headings, to gauge the change in wind speed and direction at the site. The wind turbine controller of all the floating wind turbines in the farm can directly use these measurements as input signals to pre-adjust the amount of ballast water in the columns of each floatation frame, before the wind arrives at the farm at this wind speed or direction.
On top of that, the wind turbine controllers in a farm setting can communicate with one another over a standard data network to minimize the heel angle of the platforms. At a given time, the most upwind floating wind turbine in the farm, which is the first one to experience a change of heel angle after the wind speed or direction have shifted, can share the new appropriate ballast water configuration with the other more downwind floating wind turbines. The other floating wind turbines in the farm could then anticipate any changes in wind speed and direction through the sharing of information on the data network. A “leading” floating wind turbine would dictate the appropriate ballast water configuration for the whole farm. This “leading” floating wind turbine would be determined automatically by the controller, based on its position in the farm, and the wind speed and direction measured given by the neighboring sensors. The farm of floating wind turbines is connected to an offshore substation 915 , which is ultimately connected to a shore substation 915 via electrical cables 920 .
FIG. 10 conceptually illustrates an example electronic system 1000 with which some implementations of the subject technology are implemented. Electronic system 1000 can be a computer, phone, PDA, or any other sort of electronic device. Such an electronic system includes various types of computer readable media and interfaces for various other types of computer readable media. Electronic system 1000 includes a bus 1008 , processing unit(s) 1012 , a system memory 1004 , a read-only memory (ROM) 1010 , a permanent storage device 1002 , an input device interface 1014 , an output device interface 1006 , and a network interface 1016 .
Bus 1008 collectively represents all system, peripheral, and chipset buses that communicatively connect the numerous internal devices of electronic system 1000 . For instance, bus 1008 communicatively connects processing unit(s) 1012 with ROM 1010 , system memory 1004 , and permanent storage device 1002 .
From these various memory units, processing unit(s) 1012 retrieves instructions to execute and data to process in order to execute the processes of the subject disclosure. The processing unit(s) can be a single processor or a multi-core processor in different implementations.
ROM 1010 stores static data and instructions that are needed by processing unit(s) 1012 and other modules of the electronic system. Permanent storage device 1002 , on the other hand, is a read-and-write memory device. This device is a non-volatile memory unit that stores instructions and data even when electronic system 1000 is off. Some implementations of the subject disclosure use a mass-storage device (such as a magnetic or optical disk and its corresponding disk drive) as permanent storage device 1002 .
Other implementations use a removable storage device (such as a floppy disk, flash drive, and its corresponding disk drive) as permanent storage device 1002 . Like permanent storage device 1002 , system memory 1004 is a read-and-write memory device. However, unlike storage device 1002 , system memory 1004 is a volatile read-and-write memory, such as random access memory. System memory 1004 stores some of the instructions and data that the processor needs at runtime. In some implementations, the processes of the subject disclosure are stored in system memory 1004 , permanent storage device 1002 , and/or ROM 1010 . For example, the various memory units include instructions for controlling an inclination of a floating wind turbine platform in accordance with some implementations. From these various memory units, processing unit(s) 1012 retrieves instructions to execute and data to process in order to execute the processes of some implementations.
Bus 1008 also connects to input and output device interfaces 1014 and 1006 . Input device interface 1014 enables the user to communicate information and select commands to the electronic system. Input devices used with input device interface 1014 include, for example, alphanumeric keyboards and pointing devices (also called “cursor control devices”). Output device interface 1006 enables, for example, the display of images generated by the electronic system 1000 . Output devices used with output device interface 1006 include, for example, printers and display devices, such as cathode ray tubes (CRT) or liquid crystal displays (LCD). Some implementations include devices such as a touchscreen that functions as both input and output devices.
Finally, as shown in FIG. 10 , bus 1008 also couples electronic system 1000 to a network (not shown) through a network interface 1016 . In this manner, the computer can be a part of a network of computers, such as a local area network, a wide area network, or an Intranet, or a network of networks, such as the Internet. Any or all components of electronic system 1000 can be used in conjunction with the subject disclosure.
Many of the above-described features and applications are implemented as software processes that are specified as a set of instructions recorded on a computer readable storage medium (also referred to as computer readable medium). When these instructions are executed by one or more processing unit(s) (e.g., one or more processors, cores of processors, or other processing units), they cause the processing unit(s) to perform the actions indicated in the instructions. Examples of computer readable media include, but are not limited to, CD-ROMs, flash drives, RAM chips, hard drives, EPROMs, etc. The computer readable media does not include carrier waves and electronic signals passing wirelessly or over wired connections.
In this specification, the term “software” is meant to include firmware residing in read-only memory or applications stored in magnetic storage, which can be read into memory for processing by a processor. Also, in some implementations, multiple software aspects of the subject disclosure can be implemented as sub-parts of a larger program while remaining distinct software aspects of the subject disclosure. In some implementations, multiple software aspects can also be implemented as separate programs. Finally, any combination of separate programs that together implement a software aspect described here is within the scope of the subject disclosure. In some implementations, the software programs, when installed to operate on one or more electronic systems, define one or more specific machine implementations that execute and perform the operations of the software programs.
A computer program (also known as a program, software, software application, script, or code) can be written in any form of programming language, including compiled or interpreted languages, declarative or procedural languages, and it can be deployed in any form, including as a stand alone program or as a module, component, subroutine, object, or other unit suitable for use in a computing environment. A computer program may, but need not, correspond to a file in a file system. A program can be stored in a portion of a file that holds other programs or data (e.g., one or more scripts stored in a markup language document), in a single file dedicated to the program in question, or in multiple coordinated files (e.g., files that store one or more modules, sub programs, or portions of code). A computer program can be deployed to be executed on one computer or on multiple computers that are located at one site or distributed across multiple sites and interconnected by a communication network.
These functions described above can be implemented in digital electronic circuitry, in computer software, firmware or hardware. The techniques can be implemented using one or more computer program products. Programmable processors and computers can be included in or packaged as mobile devices. The processes and logic flows can be performed by one or more programmable processors and by one or more programmable logic circuitry. General and special purpose computing devices and storage devices can be interconnected through communication networks.
Some implementations include electronic components, such as microprocessors, storage and memory that store computer program instructions in a machine-readable or computer-readable medium (alternatively referred to as computer-readable storage media, machine-readable media, or machine-readable storage media). Some examples of such computer-readable media include RAM, ROM, read-only compact discs (CD-ROM), recordable compact discs (CD-R), rewritable compact discs (CD-RW), read-only digital versatile discs (e.g., DVD-ROM, dual-layer DVD-ROM), a variety of recordable/rewritable DVDs (e.g., DVD-RAM, DVD-RW, DVD+RW, etc.), flash memory (e.g., SD cards, mini-SD cards, micro-SD cards, etc.), magnetic and/or solid state hard drives, read-only and recordable Blu-Ray® discs, ultra density optical discs, any other optical or magnetic media, and floppy disks. The computer-readable media can store a computer program that is executable by at least one processing unit and includes sets of instructions for performing various operations. Examples of computer programs or computer code include machine code, such as is produced by a compiler, and files including higher-level code that are executed by a computer, an electronic component, or a microprocessor using an interpreter.
While the above discussion primarily refers to microprocessor or multi-core processors that execute software, some implementations are performed by one or more integrated circuits, such as application specific integrated circuits (ASICs) or field programmable gate arrays (FPGAs). In some implementations, such integrated circuits execute instructions that are stored on the circuit itself.
As used in this specification and any claims of this application, the terms “computer”, “server”, “processor”, and “memory” all refer to electronic or other technological devices. These terms exclude people or groups of people. For the purposes of the specification, the terms display or displaying means displaying on an electronic device. As used in this specification and any claims of this application, the terms “computer readable medium” and “computer readable media” are entirely restricted to tangible, physical objects that store information in a form that is readable by a computer. These terms exclude any wireless signals, wired download signals, and any other ephemeral signals.
To provide for interaction with a user, implementations of the subject matter described in this specification can be implemented on a computer having a display device, e.g., a CRT (cathode ray tube) or LCD (liquid crystal display) monitor, for displaying information to the user and a keyboard and a pointing device, e.g., a mouse or a trackball, by which the user can provide input to the computer. Other kinds of devices can be used to provide for interaction with a user as well; for example, feedback provided to the user can be any form of sensory feedback, e.g., visual feedback, auditory feedback, or tactile feedback; and input from the user can be received in any form, including acoustic, speech, or tactile input. In addition, a computer can interact with a user by sending documents to and receiving documents from a device that is used by the user; for example, by sending web pages to a web browser on a user's client device in response to requests received from the web browser.
Embodiments of the subject matter described in this specification can be implemented in a computing system that includes a back end component, e.g., as a data server, or that includes a middleware component, e.g., an application server, or that includes a front end component, e.g., a client computer having a graphical user interface or a web browser through which a user can interact with an implementation of the subject matter described in this specification, or any combination of one or more such back end, middleware, or front end components. The components of the system can be interconnected by any form or medium of digital data communication, e.g., a communication network. Examples of communication networks include a local area network and a wide area network, an inter-network (e.g., the Internet), and peer-to-peer networks (e.g., ad hoc peer-to-peer networks).
The computing system can include clients and servers. A client and server are generally remote from each other and typically interact through a communication network. The relationship of client and server arises by virtue of computer programs running on the respective computers and having a client-server relationship to each other. In some embodiments, a server transmits data (e.g., an HTML page) to a client device (e.g., for purposes of displaying data to and receiving user input from a user interacting with the client device). Data generated at the client device (e.g., a result of the user interaction) can be received from the client device at the server.
It is understood that any specific order or hierarchy of steps in the processes disclosed is an illustration of approaches. Based upon design preferences, it is understood that the specific order or hierarchy of steps in the processes may be rearranged, or that all illustrated steps be performed. Some of the steps may be performed simultaneously. For example, in certain circumstances, multitasking and parallel processing may be advantageous. Moreover, the separation of various system components in the embodiments described above should not be understood as requiring such separation in all embodiments, and it should be understood that the described program components and systems can generally be integrated together in a single software product or packaged into multiple software products.
The previous description is provided to enable any person skilled in the art to practice the various aspects described herein. Various modifications to these aspects will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other aspects. Thus, the claims are not intended to be limited to the aspects shown herein, but are to be accorded the full scope consistent with the language claims, wherein reference to an element in the singular is not intended to mean “one and only one” unless specifically so stated, but rather “one or more.” Unless specifically stated otherwise, the term “some” refers to one or more. Pronouns in the masculine (e.g., his) include the feminine and neuter gender (e.g., her and its) and vice versa. Headings and subheadings, if any, are used for convenience only and do not limit the subject disclosure.
A phrase such as an “aspect” does not imply that such aspect is essential to the subject technology or that such aspect applies to all configurations of the subject technology. A disclosure relating to an aspect may apply to all configurations, or one or more configurations. A phrase such as an aspect may refer to one or more aspects and vice versa. A phrase such as a “configuration” does not imply that such configuration is essential to the subject technology or that such configuration applies to all configurations of the subject technology. A disclosure relating to a configuration may apply to all configurations, or one or more configurations. A phrase such as a configuration may refer to one or more configurations and vice versa. | A method for controlling an inclination of a floating wind turbine platform comprising a generator, a set of turbine blades connected to a shaft inside a turbine nacelle, the turbine nacelle being mounted onto a tower, and at least three stabilizing columns is presented. Each of the at least three stabilizing columns have an internal volume for containing ballast. Position data associated with an orientation of the floating wind turbine is received. A heel angle in reference to the floating wind turbine platform is determined based on the position data. A first signal for adjusting at least one of a blade pitch of the set of turbine blades, and a torque of the generator is sent based on the determined heel angle. A second signal for distributing the ballast among the at least three stabilizing columns is also sent. The second signal for distributing the ballast is based on the determined heel angle and the first signal. | 8 |
CROSS REFERENCE TO RELATED APPLICATIONS
This is a division of application Ser. No. 445,501, filed Feb. 25, 1974, now U.S. Pat. No. 3,937,043.
This application contains, in its description, matter common to co-pending cases Application Ser. Nos. 445,028, 445,503 and 445,504, of common assignee with the present application.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to an air flow system for a dry cleaner for inducing ambient air to flow into the access opening of the machine whenever the door is opened. Such systems have previously been referred to as air exhaust systems; however, the present invention is particularly adapted to provide the air flow without exhausting the tubs.
2. Description of the Prior Art
As a safety feature in dry cleaning machines, an air flow system is provided for drawing ambient or room air in through the access opening to the interior of the machine whenever the door to the machine is opened. This air flow minimizes the escape of toxic solvent vapors out the access opening so that the user will not be subjected to such vapors when loading or unloading clothes from the machine. Heretofore, this air flow was commonly induced by the fan or blower which also was used during the drying cycle to circulate heat through the tubs. Also, to some extent, there were common ducts for each system with a diverter valve for determining whether the air would flow through the recirculating path or to an exhaust outlet. In machines using a relatively inexpensive solvent having normal volatility, the loss of residual solvent vapors from the interior of the tubs and the common ducts was of limited concern. Thus, the air flow system for inducing ambient air to flow in through the door was typically included in the tubs, exhausting the tubs of the residual solvent vapors therein and thus losing them to the atmosphere.
The use of a cleaning solvent which is substantially more expensive and of greater volitality required, for economic reasons, that the residual solvent vapors remaining in the tubs and air recirculating system at the end of the cleaning cycle not be exhausted to atmosphere but, of necessity, retained within the confines of the machine. However, it remains necessary to induce an air flow in through the access whenever the door to the machine is opened.
SUMMARY OF THE INVENTION
The dry cleaning machine of the present invention provides an air flow system for bringing ambient air into the access opening whenever the door is opened which is exclusive of the air recirculating system and substantially reduces exhausting the residual solvent vapors from the tubs. Thus, a separate intake fan and duct is provided with the duct interposed between the access opening of the machine housing and the open ends of the interior tubs, and includes a normally closed valve so that during normal operation of the machine the separate intake system is isolated from the solvent vapors developed during the cleaning cycle. In response to the access door being opened, the intake fan is energized and the valve is opened so that air is drawn into the access opening and directly into the interposed duct with only that vapor generally immediately adjacent the open end of the tubs commingling with the intake air and lost to atmosphere. However, for the most part, the vapors within the tubs are retained and the loss of solvent is minimized.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective schematic drawing of the dry cleaner primarily showing the solvent distributing system and the air distributing system of the present invention;
FIG. 2 is a perspective schematic drawing similar to FIG. 1 for primarily showing the air distributing system and a refrigeration system for solvent vapor recovery;
FIG. 3 is a timer cycle chart indicating the timer-energized components during each portion of the dry cleaning cycle; and,
FIG. 4 is a simplified schematic wiring diagram showing the machine controls.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring initially to FIGS. 1 and 2 it is seen that the dry cleaner 2 of the present invention is generally of known construction in that it includes a pair of nested tubs 4, 6 having a common horizontal access with the outer tub 6 generally stationarily supported and the inner tub 4 rotatably supported, and an outer cabinet 8 (shown in dotted lines in FIG. 1) having an access opening in alignment with the open end of the tubs and supporting a front opening door 9 for access to the inner tub 4. The cabinet 8 encloses the other operative elements of the dry cleaner such as the drive motor (see FIG. 4) coupled through a well-known belt and pulley drive to the inner tub 4 for either reversibly slowly rotating the tub or spinning the tub at a relatively high speed. Also included is a pump 24 for pumping the dry cleaning solvent from a storage tank 20 into the tub 6 through a filter 14 in the housing 36, and back into the storage tank and a blower 16 for circulating heated air through the tubs for drying the clothes.
The forward concentric openings of the tubs 4 and 6 are spaced from the wall of the cabinet having the opening to accommodate therebetween a header chamber 11. This chamber has opposed walls 11a defining concentric openings which in turn are in alignment with the cabinet opening and tub openings respectively to provide an access opening therethrough for the clothes. The walls of the chamber are also sealingly attached to the cabinet structure and outer tub 6, with the periphery of the forward opening bounded by a forwardly extending flange for sealingly engaging the inner face of the door when in a closed position. The upper portion of the chamber above the openings defines a plenum into which the air from the air blower is directed so that it enters the tubs at the forwardmost portion thereof, and also from which exhaust air is drawn as will be explained later.
The complete operation of the electrical components dictating the type of operation being performed is controlled through a well known timer mechanism 18 generally enclosed adjacent the rear of the housing in an area generally inaccessible to the customer/user.
The operative cycle of such a machine, maintained normally in a stand-by condition, includes, after the cleaning cycle is initiated, a washing portion wherein the solvent is delivered to the tub 6 during slow speed rotation thereof so that the clothes are randomly moved about within the solvent, a drain portion wherein the solvent is drained from the tub 6, a spin or centrifuging portion wherein the solvent is extracted from the clothes, and a drying portion when the clothes are again randomly moved about within the tub 4 in the presence of circulating heated air.
The present invention is better described with specific detail to the separate circulating systems within the machine. In this regard each system will be described as it functions through the various distinct portions of the complete cleaning cycle.
SOLVENT FLOW SYSTEM (FIG. 1)
Stand-by
Anytime the machine is not being used it is in a stand-by condition ready for use by merely closing the access door and depositing the appropriate coins. While in the stand-by condition there is no flow of the solvent within the machine, with the solvent being stored in tank 20.
Fill and Wash
After the clothes are loaded into the inner tub 4, the cleaning cycle is initiated, as by closing the access door 9 and depositing the correct change, which energizes the solvent pump 24. This pumps the solvent from the storage tank 20 through pump inlet line 22 into pump 24, hence to discharge pipe 26 and in one side 28A of a diverter valve 28 normally oriented to direct the flow into line 30 through nipple 29.
From line 30 the solvent passes through another diverter valve 32 which normally directs the flow into pipe 34 which is the inlet pipe of a housing 36 enclosing a pair of pleated paper and charcoal filters (not shown). After passing through the filters, the solvent exits the housing through outlet 38 which leads through a sight-glass 40 and manual valve 42 into leg 44 of a T-connector 46. The opposite leg of the T-connector leads to a oneway valve 48 which is set up to prevent flow therethrough from the connector. Thus, the solvent goes to another diverter valve 50 normally directing the flow into yet another diverter valve 54 through a nipple 52. Valve 54 normally directs the flow into pipe 56 which leads into the outer tub 6.
Once the tub 6 fills to a predetermined level, any further solvent coming into the tub causes the solvent to flow out the tub 6 through the overflow line 60. It is to be noted that a drain or dump line 62 also leads from the tub 6, but as this line is closed by a motor drive valve 64 at this time, the solvent can exit the tub only via line 60.
Line 60 also has a motor driven overflow valve 66 which at this time is open permitting flow of the solvent into line 68 connected to a housing 70 containing a button trap (as is well known in the art) enclosing a perforated container 72 interposed between the inlet and the outlet pipe 74 leading back to the storage tank 20.
This recirculation of the solvent from the storage tank through the filters, into the tubs, through the button trap, and back to the tank, is continuous throughout the fill and wash portion of the cycle.
Dump and Spin
At the termination of the wash cycle, although the clothes tub 4 continues to tumble the clothes, the above-described flow circuit is altered to provide two separate solvent flow paths. The first provides continuous filtration of the solvent by continuing to pump the solvent from the tank 20 through the filters via the route described above with the exception being that valve 54 has now been energized and directs the solvent into line 76 which leads directly back to tank 20. Thus, no more solvent enters the tubs. The other path dumps the solvent already in the tubs into the tank 20. This is done by opening valve 64 of line 62 for flow therethrough into another inlet pipe 78 of button basket 72 before flowing through outlet pipe 74 to the storage tank 20. This flow path is maintained all during the drain and subsequent spin portion of the cycle. Also, for purposes of air pressure balance through the solvent distributing system, overflow valve 66 remains open during this portion of the cycle.
Tumble Dry With Heat
During this portion of the cycle the solvent continues to flow through the filtering cycle above described; however, valves 64 and 66 are closed, which in conjunction with valve 54 closing the solvent inlet line to the tub, (as is the case with the filtration flowpath utilized), the solvent flow system is isolated from any evaporative air circulated during the dry cycle.
Last Minute Of The Cycle
During the last minute of the cycle, the solvent which has been flowing in one direction through the filters, is caused to flow through the filters in a reversed direction in an operation known as "backwash". (Again see the U.S. Pat. No. 3,253,431 of common assignee.)
Thus, as before, the solvent is drawn from tank 20 through pipe 22 into pump 24 and discharged to line 26 into valve 28. This diverter valve has now been energized to direct the flow into line 88 and into valve 50 which also has been energized to direct flow into leg 44 of connector 46, thence through manual valve 42, sight-glass 40 and into the outlet 38 of the filter housing 36.
The solvent exits the housing 36 through inlet 34 and into diverter valve 32 which is energized to divert the solvent into line 82 leading to the top of the button tank 70 which, as is also well known, houses a backwash bag which filters particles from the solvent as it passes therethrough into the button basket for return to the tank 20 via line 74.
A filter housing breather line 86 connects the upper end of the filter housing 36 with the button basket tank 70 to bleed any air entrapped therein out of the housing and into a suitable place. Any solvent that may flow therethrough goes directly to the button tank 70 and back to the storage tank 20.
It is important to note that valves 54, 64, and 66 still maintain the solvent distributing system isolated from the circulating drying air.
To complete the solvent flow system, a safety line 132 connects the top of the button tank 70 with a line 128 (a solvent vapor handling line to be explained subsequently) leading directly into storage tank 20. This line 132 accommodates the solvent flow in the event the button trap 70 becomes clogged to the extent that return flow to the tank 20 through line 74 is blocked. Thus, under this condition, the button trap would fill with solvent to the line 132 which would deliver it back to the tank 20 at a rate capable of accommodating the pump capacity during the filtering portion of the cycle.
AIR FLOW SYSTEM (FIG. 2)
As previously explained, the header chamber 11 is attached to the outer tub 6 at the tub's forward opening. This header chamber 11 thus is in air-flow communication with the inner tub 4 through the forward facing opening of the tub. The header chamber has attached thereto a pair of airflow hoses 118 and 122. Another air hose 96 is attached to the stationary outer tub 6 at some point axially remote from the header chamber 59. Each hose in turn is associated with an electrically energized oneway valve 90, 92, and 94 respectively, for controlling the flow through these hoses, these being the only airflow ingress or egress lines connected to the tubs.
Stand-By With Access Door Closed
During this time there is no airflow as no blower is energized and valve 90, 92 and 94 are normally closed. However, should the door become open, a door switch immediately energizes valve 92 and an exhaust blower 120. Thus, it is seen ambient room air is drawn through the front opening and immediately drawn into the upper portion of the header chamber 11 with minimal penetration into the interior of the tubs so that the solvent vapors within the tub are not exhausted while the air is being drawn through the front opening to prevent the user, when loading or unloading clothes, from encountering solvent vapor fumes.
Fill And Wash
Again there is no airflow during this portion of the cleaning cycle as valves 90, 92 and 94 remain closed and no blower is energized. Thus, during this portion of the cycle the solvent in the tub is not exposed to any circulating air.
Drain And Spin
During the drain portion of the cycle, valve 90 associated with the air inlet side of header chamber 59 and valve 94 associated with the air outlet side of the tub 6 are both open to assist in balancing the air pressure throughout the interior of the machine (with no blower being energized) as the solvent is drained from the tubs. However, once the drain portion is completed and the inner clothes tub 4 is energized to spin, all valves 90 and 94 are again closed. This again isolates the air within the tubs and prevents any air circulation through the air distributing system which could be induced by the spinning tub even though no blower was energized if such valves were open.
Elimination of the airflow through the clothes during spin by isolating the tubs as above described is important with respect to minimizing the undesirable phenomena associated with dry cleaning and referred to in the trade as "streaks and swales". These are darker areas in the form of spots and lines that form in the clothes when certain areas dry faster than others and before the solvent has a chance to be distributed generally equally throughout the clothes. Thus, in these areas, generally adjacent the creases or folds in the clothes which are dried quite rapidly, a concentration of non-volatile residue (N.V.R.) carried by the solvent as a result of cleaning the clothes, is present which is highly visible as darker streaks at the interface of the faster dried areas and the subsequently dried area of the clothes.
It logically follows that the greater the volatility of the solvent, i.e. the more readily the solvent vaporizes, the more likely it will be for uneven drying to occur, forming the streaks and swales. The uneven drying as accenuated by the spinning tub, which in addition to maintaining the clothes in a fixed position by virtue of the centrifugal force, also normally induces an air circulation through the tub, created by the high speed spinning of the clothes and tub acting as a blower.
It has been found that the formation of the streaks swales can be greatly reduced and even eliminated by preventing airflow through the tub during the spin cycle. This, in addition to decreasing the vaporization of the solvent from the exposed surfaces of the clothes due to air movement, prevents escape of the vaporized solvent, thereby permitting the vapor pressure within the tub to increase somewhat which itself retards further vaporization. Thus, although a solvent having a higher degree of volatility is used in this machine, the formation of streaks and swales is greatly reduced by having valves 90 and 94 closed during centrifugal extraction.
Tumble Dry With Heat
One minute after the start of the drying portion of the cycle wherein the tub 4 is again reversibly driven at a tumble speed, valves 90 and 94 are opened. This initial minute with the above valves closed permits the clothes to be in a tumbling mode before the flow of drying air is initiated. This is in furtherance of preventing rapid drying of selective areas for eliminating streaks of swales by letting the clothes move randomly about before being subjected to the rapid drying affects of the hot air.
Once the valves 90 and 94 are opened and blower 16 energized, the air and vapor mixture exits the tubs 4, 6 through hose 96 which leads into a lint box 98 having a lint screen 100. After passing through the lint box, air goes through valve 94, and then to hose 102 of the inlet of blower housing 104 enclosing the blower 16. From there the air/vapor mixture goes through hose 106 and into condenser housing 108. Condenser housing 108 contains the evaporator coils 110 of a refrigeration unit (to be described) which condense the solvent vapor from this air and vapor mixture.
The air exits housing 108 through hose 112 which leads into a heater box 114 enclosing a cast aluminum finned resistance heater 116, where the temperatures of air is elevated to a predetermined level. (It is noted in FIG. 3 that the heater has been energized a sufficient length of time prior to the flow thereover to insure the heater is at the elevated temperature when the airflow through the tub 4 begins.) From the heater box 114 the heated air flows into inlet valve 90 and thence into the inlet of header 59 to flow through the clothes in the tub 4, vaporizing the solvent from the clothes and repeating the closed circulation path described continuously through the dry portion of the cycle. At the termination of the dry portion of the cycle the blower 16 stops, valves 90 and 94 close and the front opening access door is permitted to be electrically unlocked by manual depression of a door opening switch. (It should be pointed out that once the cycle has been initiated the door is mechanically locked in a manner that can only be unlocked through the electrical energization of a solenoid that is prevented from being energized until the cycle is complete and subsequently described with reference to FIG. 4.)
Clothes Removal
Once the dry portion of the cycle is completed as above described, the machine is no longer controlled by the timer but is in a stand-by condition ready to repeat a cleaning cycle. However, for removal of the clean clothes, the access door must be open. And, as previously explained, anytime the door is open an exhaust fan 120 is energized through a door switch 140 (see FIG. 4) along with exhaust valve 92, also energized through the door switch 140, being opened. Thus, air is forced to enter the front opening, flow directly into the header chamber 11, through valve 92 attached thereto and into the blower 120. From the blower the air flows through hose 122 which in turn is to be connected to a venting system for the building housing the dry cleaner.
The airflow with the door open is thus limited to an exit path that is exclusive for exhausting and does not cause air to flow through the interior of the tubs 4, 6 thus minimizing the loss of solvent vapor to the exhaust. Also, the exhaust, to satisfy established requirements, causes air to flow through the door opening at a minimum rate of 100 linear feet per minute.
SOLVENT VAPOR HANDLING (FIG. 2)
During the fill portion of the cycle, the air in the tubs 4, 6 is displaced by the incoming solvent. Also, the warmer surfaces of the tubs cause some of the incoming solvent to vaporize. The closed door prevents this vapor from escaping through it and with the valves 90 and 94 closed, the air/vapor mixture is forced (by pressure) into hose 96 leading to lint box 98.
An exit hose 124 leads from the lint box to an expandable closed impervious bag 126, preferably plastic and housed in a container (not shown) located in the upper portion of the machine. The bag expands to accommodate and retain the air-vapor mixture. This bag keeps the pressure within the machine within low enough limits such that positively sealing the machine against the existing pressure to prevent leakage does not become prohibitively expensive as it would if the solvent vapor remained in the confines of the tub and attached hoses. In practice the pressure within the machine tends to stabilize at approximately one-half psi as opposed to approximately ten psi without the bag.
A safety release valve 130 is interposed in line 124 and adjusted to open under a somewhat greater pressure than one-half psi to insure that the internal stays within an acceptably low limit. However, under most circumstances valve 130 will not be required to open.
During the wash portion of the cycle, the vapor pressure within the tubs and line 96 tends to stabilize so that there is minimal air/vapor movement. Also, during the dump portion of the cycle, even though valves 90 and 94 are open, there is very little air/vapor flow from the bag 126 as the increasing volume in the tubs decreases the vapor pressure which in turn permits more solvent to vaporize to fill this space. The valves 90 and 94 being again closed for the spin portion of the cycle prevent air/vapor flow from the bag.
However, during the dry portion of the cycle with valves 90 and 94 open, the air is circulated as previously described. It is noted that line 24 is on the suction side of recirculating blower 16 so that with the blower 16 energized, the air/vapor mixture in the bag, being at a greater pressure and at an elevated position with respect to the suction inlet to the blower, is forced back into the flow stream via the lint box 98, until the bag 126 is evacuated. The vapor in this air/vapor mixture is then recovered in the same manner as the vapor driven from the clothes during the drying operation is recovered. The bag is evacuated well before the termination of the drying operation.
The relatively warm ambient temperature causes some of the solvent in the storage tank 20 to vaporize. This vapor is removed from the tank (to prevent pressure buildup therein) by a breather line 128 leading to condenser box 108. As the air passage through the condenser box 108 is blocked by valves 90 and 94 during all portions of the cycle except drain and dry, the box 108 and the hoses connected thereto act like a chamber providing additional volume to accumulate and retain the vapors. However, during this time, should the pressure increase beyond an acceptable level, (i.e. somewhat less than one-half psi) the vapors can by this pressure, be forced through line 106, backwards (in relation to the normal direction of flow) through recirculating fan 16, into hose 102. This pressure is then on the back face of closed valves 94 which is oriented to prevent flow in the other direction, but with back-pressure thereon, opens sufficiently for the vapors to leak through it and into box 98. From there the vapors go through line 124 for retention in the expandable bag 126 for subsequent reclamation as previously described.
During the drain portion of the cycle, the vapors generated in the tank 20 and directed to the condenser housing 108 are permitted to flow through the heater box 114 and into the tubs 4, 6 through the then open valve 90 for subsequent reclamation during the dry portion of the cycle, whereas during the dry portion, when the evaporator 110 is operating, the vapors directed into the condenser box 108 from either the tub or the tank are condensed.
In addition to condensing solvent vapor, the evaporator 10 in the condenser housing also condenses water vapor evaporated from the clothes during the dry portion of the cycle. This water/solvent mixture is directed from the condenser housing 108 by gravity flow through line 134 to the water separator housing 136 where, because of the difference in the specific gravity between the two liquids, the solvent can be removed from the water by lines exiting the separator at different levels as is well known in the art. Thus, the water goes through the separator 136 through line 138 into a closed container 140 for intermittent manual dumping. The solvent exits the housing 136 through line 142 to return to the storage tank 20.
REFRIGERATION SYSTEM (FIG. 2)
Stand-by
A compression-type refrigeration system is provided in the dry cleaner for condensing the vapors in the condenser box 108 and also for maintaining the liquid solvent in the storage 20 at a predetermined temperature to minimize the vaporization therein. The system is best seen in FIG. 2 and operates to cool the storage tank under all portions of the cycle except the drying portion. Thus, the description for stand-by includes these other portions of the cycle.
Thus, whenever the thermostat 141 within the tank 20 exceeds a predetermined limit (80°F) the refrigeration unit is energized with cooling directed to the evaporator coil 144 in the storage tank 20. In the system shown the refrigerant flow path includes a compressor 146 with a compressed refrigerant directed therefrom through line 148 to refrigerant condenser 150, accumulator 152, filter 154 and sight-glass 156 to T-connector 158. Of the two lines 160 and 162 leading from the T-connector 158, line 160 contains a normally closed valve 164 which thus prevents flow therethrough. However, line 162 contains a normally open valve 166 permitting the refrigerant to flow into line 168 leading to expansion valve 170 and evaporator coils 144 in the storage tank 20. From there the refrigerant is directed back to the compressor 146 through line 172 and T-connector 174. Once the solvent in the tank has been cooled to around 75°F, the refrigeration system is deenergized, but ready to repeat the cycle whenever the temperature exceeds 80°F.
Dry
During the dry portion of the cleaning cycle the refrigeration unit is continuously energized through a switch 143 (See FIG. 4) controlled by the timer. At this time the refrigerant flow from the compressor 146 is identical to that described above until it reaches the T-connector 158. The flow path from there is altered by the normally closed valve 164 being energized to an open position and the normally open valve 166 being energized to a closed position. Thus, the refrigerant is directed into evaporater coil 110 of the condenser housing 108 for continuous condensing of the solvent vapors passing therethrough during this time, and maintaining a substantially fixed temperature therein over the varying load conditions. From there the refrigerant 146 passes through line 176 leading to T-connector 174.
It is noted that during the dry portion of the cycle, the temperature of the solvent in the storage tank 20 can exceed the 80°F temperature without refrigeration being directed thereto. However, as this dry portion is a relatively short-term operation, the temperature rise is never too much beyond the 80°F and also the increased rate of vaporization is accommodated through the breather line 128 directing the vapor to the condenser housing where it is condensed and returned to the storage tank, as previously explained, as relatively cool solvent.
Further, as the refrigeration unit is sized in accordance with the heat removal required of it during the drying portion of the cycle (this being the greatest load it must accommodate) its refrigeration capacity is greatly in excess of that needed to maintain the solvent within the predetermined temperature range during all other portions of the cycle. Thus an alternative refrigeration control system would be to eliminate the normally closed valve 164 in line 160 and make valve 166 (previously identical as being normally closed valve. In this arrangement, during all portions of the cleaning cycle except drying, the now normally closed valve 166 would be opened in response to the thermostat sensing a predetermined limit and the refrigerant would then flow into the evaporator coils 144 in the tank 20. As the refrigerant line to the evaporator coils 110 is also opened (because there is no valve) a portion of the refrigeration would also flow into it, however, because of the oversized capacity of the unit, sufficient refrigerant would flow to the coils 144 to cool the tank.
During the dry portion of the cycle, valve 166 would be prevented from being energized by the thermostat, and thus being a normally closed valve, would direct all the refrigerant into the coils 110 to condense the vapors in the circulating drying air. This last described system permits the elimination of one valve 164 from the previously described system.
Thus, the refrigeration system has a single compressor for alternatively primarily cooling two distinct evaporator coils under either a continuously timed demand for one coil or a cyclical temperature responsive demand for the other coil, with the time demand having precedent.
CONTROLS (FIG. 4)
As previously stated and as is well known in the art, the automatic dry cleaning machine is controlled for the most part through a timer mechanism 18 mounted in the back portion of the housing so as to be generally accessible to only certain personnel so that the cleaning cycle cannot normally be altered in any way.
However, in the present invention, provision is made for purposely altering the timer operation to provide what would normally be a dry portion of the cycle, but without rotating the tub or advancing the timer to other portions of the cycle. This modified dry operation is thus utilized to dry the filter cartridges, which must occasionally be replaced, prior to them being discarded to reclaim any residual solvent or solvent vapors therein that remain after the filters are removed from their housing 36 for replacement.
Normally, the proprietor would know when it was time to change the filters and would preferably allow the machine to remain quiescent for some period of time to permit solvent to gravitationally drain from the filters. However, as this does not remove all the recoverable solvent, the present machine permits the filters to be placed within the tub 4 and the control mechanism set to provide the above operation identified as "cartridge dry" on the timer control panel. To actuate the mechanism to this procedure, a switch (to be discussed) is included on the control panel having one switch arm serially connected in the timer motor circuit and another switch arm serially connected in the main motor circuit so that in the "cartridge dry" position of this switch, both motors are inactive. After placing the switch in this position, the timer is manually turned to any point in the dry portion of the cycle, thereby actuating all elements previously identified to accomplish a drying process within the machine. After some length of time sufficient to dry the cartridges, the cycle is manually terminated by turning the timer to an "off" position and returning the "cartridge dry" switch to the normal position, thereby readying the machine for further use by the customer.
Reference is now made to FIG. 4 to briefly describe the controls of the machine and particularly those appliciable to the "cartridge dry" operation. Thus, it is seen that the control circuit includes a door switch 160 which, and the position shown, represents the access door being closed, and which is necessary for the machine to operate. It is noted that in the door open position, switch 160 would simultaneously energize the exhaust valve 92 and exhaust door 120 for air flow through the access opening as previously explained.
A control box switch 162 is in series with one side of the door switch and, in the position shown, indicates the termination of the cleaning cycle and thus the stand-by position. As the access door is mechanically locked, whenever closed, it can only be unlocked for acces when this switch 162 is in the position shown by manually depressing a door unlock switch 164 which energizes an unlocking solenoid 168.
Once coins are deposited to initiate the cleaning cycle, the control box switch moves to its other position to energize the appropriate timer contacts and deactivate the line having the door unlock switch 164 so that the door can no longer be unlocked.
The timer 18 as well known, includes a plurality of cam actuated switches (only certain ones being illustrated) with the controlling cams rotatingly driven by a timer advancing motor 174. Also, as can be seen, the main motor 176 of the machine is controlled through a timer switch. The "cartridge dry" switch 172 is interposed in each motor line so that when moved to the "cartridge dry" position, contact 172A to the timer motor is opened along with contact 172B to the tumble winding of the main motor (the tumble winding being the winding that is energized through the timer when the timer is positioned in the dry portion of the cycle) thus preventing either advancement of the timer mechanism or rotation of the inner tub 4. When it has been determined that the cartridges are dry, the machine is returned to the normal operating condition by closing switch 172 and returning the timer to the initiation point of the dry cleaning cycle. | An ambient air intake system for a dry cleaner is disclosed which draws room air through the access opening when the door to the machine is open and vents this air to an outlet without passing it through the interior tubs which contain residual solvent vapor laden air. To accomplish this an air duct is interposed between the access opening of the cabinet housing the dry cleaner and the open end of the interior tubs, with the duct effectively sealed about the periphery of the cabinet opening and the open end of the outer tub and having aligned openings therethrough to define a passageway through which the clothes are inserted and removed. The duct is connected to an electrically actuated normally closed valve which in turn is connected to the inlet of a motor driven fan, the outlet side of which leads to an exhaust pipe. Both the valve and the fan are energized by a door switch when the door associated with the access opening is opened to draw ambient air into the accessed opening, then immediately into the air duct to be exhausted without passing into the interior of the tubs. This minimizes the commingling of the ambient air and the vapor laden air within the tubs to reduce the loss of solvent when the access door is opened. | 3 |
FIELD OF THE INVENTION
This invention relates generally to the analysis of pressure data that is obtained during injection of fracturing fluids into an earth formation in order to determine fracture behavior and events, and particularly to a new and improved method that involves use of the logarithmic derivative of such pressures to determine minimum in-situ stress or closure pressure, and to identify fracturing events such as extension of the fractures with confined height or with height growth, and to provide early detection of screenout.
BACKGROUND OF THE INVENTION
The oil and gas products that are contained, for example, in sandstone earth formations, occupy pore spaces in the rock. The pore spaces are more or less interconnected to define permeability, which is a measure of the ability of the rock to transmit fluid flow. If permeability is low, or when some damage has been done to the formation material immediately surrounding the bore hole during the drilling process, a hydraulic fracturing operation can be performed to increase the production from the well.
Hydraulic fracturing is a process where a fluid under high pressure is applied against the formation to split the rock and create fractures that penetrate deeply into the formation. The fractures provide additional flow channels, as well as more surface area through which formation fluids can flow into the well bore. The result is to improve the near term productivity of the well, as well as its ultimate productivity, by providing flow channels that extend farther into the formation. Most wells of this type are fractured upon initial completion, and are refractured at a later date to restore productivity To prevent healing of the fractures after the parting pressure is released, it has become conventional practice to use propping agents of various kinds to hold the cracks open, and spacer materials to ensure optimum distribution of the proppants.
During fracturing, fluids are injected into the formation at a given rate in order to initiate the fractures and then propagate them. Calibrations can be made to determine key design parameters, or propping agent treatments. The efficiency of fracturing treatments rely heavily on the ability to produce fractures that have optimum physical characteristics such as length, height, width and flow capacity. Such characteristics can be predetermined to some extent by using a reservoir model, together with certain selected economic criteria. A determination of the closure pressure, and the identification of fracturing events such as height growth and/or the occurrence of screenout (proppant bridging that restricts fracture extension), in a timely manner, is crucial to the economic success of a fracturing operation, and to any future operations in the same geographical area by appropriate modification of the design criteria.
It is known that fracture behavior and certain fracturing events cause characteristic changes or patterns of change, in downhole pressures. As an aid to pressure change pattern recognition from which a model that defines the fracturing process can be inferred, it is known in the art to plot net pressure values versus pumping time on a log-log scale, where net pressure is the difference between bottom hole pressure and the in-situ stress or fracture closure pressure. See Nolte and Smith U.S. Pat. No. 4,393,933 issued Jul. 19, 1983, and "Interpretation of Fracturing Pressures", Nolte and Smith, Journal of Petroleum Technology Sep. 1981, p. 1767. A low, positive slope for this net pressure plot indicates so-called "PKN" behavior where the fracture is one that penetrates deeply into the formation with height confinement. A low, negative slope of the plot indicates "KGD" behavior where fracture height is much larger than its penetration into the formation, and can also indicate a radial or a penny-shaped fracture. A portion of the plot that has a substantially flat slope is indicative of the opening of natural fissures in the rock and accelerated fluid leakoff. This phenomenon may result in "screenout", which, as mentioned above, is a condition where propping agents bridge the fracture and restrict further extension thereof. Screenout itself is characterized by a section of the plot that has a relatively high positive slope of about one, or even higher. The net pressure plot has served as a very useful pattern recognition tool for interpreting fracturing pressure data, and enables a diagnosis to be made of certain fracturing events.
However, the use of the net pressure plot depends upon the existence of certain input data which can be ill-defined. The time origin is when the fracture is initiated, which usually is taken to be the time at which the gelled fluids hit the formation. The slopes exhibited by the net pressure plot depend to some extent on the value of the closure pressure, which has to be measured independently, preferably using in-situ stress tests. Failure to have the actual closure pressure can result in an inaccurate slope of the plot. A net pressure plot with a small positive slope may appear to be flat if the closure pressure that was selected is too low, and vice versa. Consequently an inaccurate interpretation of fracture behavior can be made if the error is not detected. In addition, certain important fracturing events can be difficult to detect in a timely manner due to compression of the data that is imposed by a logarithmic scale. Thus, there remains the need to enhance pattern recognition techniques in a manner that will obviate the foregoing limitations, and enhance the sensitivity of the analysis.
The general object of the present invention is to provide a new and improved method of analyzing the pressure data during a well fracturing operation that enhances early identification of certain fracturing events, such as extension of a fracture with confined height, or with height growth, as well as early detection of the onset of screenout.
Another object of the present invention is to provide a new and improved method of analyzing pressure data during a well fracturing operation that enable a more accurate determination of minimum in-situ stress or closure pressure.
SUMMARY OF THE INVENTION
These and other objects are attained in accordance With the concepts of the present invention through the performance of methods comprising the steps of pumping a fracturing fluid, preferably at a constant rate into a formation to create fractures in the rock, measuring the downhole pressures during such pumping step, determining the logarithmic derivative of the pressure data, plotting such derivative on a log-log scale as a function of time elapsed after initiation of a fracture, and determining the type of fracture and its propagation characterization from the general shape and slope of certain portions of the plot. Minimum in-situ stress can be determined by choosing a closure pressure value which, when subtracted from the fracture pressures yields a straight line on the plot having the same slope as the derivative plot for two dimensional and radial fractures. It can be demonstrated that the derivative is unaffected by the value of the closure pressure that is actually used, so that the effects of using an inaccurate closure pressure in a net pressure plot are eliminated. Indeed, the slope obtained from the derivative plot can be used directly to estimate the correct closure pressure. Where the fracturing fluid carries a propping agent, the derivative plot also has a characteristic slope which is indicative of an actual or potential screenout, which is evident much earlier in time than with the use of prior interpretation techniques.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention has other objects, features and advantages which will become more clearly apparent in connection with the following detailed description of preferred methods, taken in conjunction with the appended drawings in which:
FIG. 1 is an illustration of a log-log net pressure plot showing various types of fracture behavior and certain fracturing events;
FIG. 2 is a log-log plot of the derivative of the pressure values and several net pressure plots, to illustrate how the correct closure pressure value can be determined;
FIG. 3 is a log-log plot of both net pressure and the derivative that illustrates detection of stable height growth;
FIG. 4 is a plot similar to FIG. 3 of both net pressure and the derivative that illustrates early detection of a fracture tip-type screenout;
FIG. 5 is a plot similar to FIG. 4 which is diagnostic of a near well bore screenout; and
FIG. 6 is a log-log plot of net pressure and the pressure derivative taken from actual field data.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
FIG. 1 illustrates a generalized "net pressure" plot of downhole well bore pressures vs. pumping time on a log-log scale. The ordinates of the plot represent the differences between bottom hole pressure and in-situ stress or closure pressure of the rock, and the abscissae values represent elapsed pumping time. The curve portion 10 having a constant positive slope is indicative of "PKN" behavior of a fracture where it extends outwardly into the rock with vertical height confinement. The curve portion 11 which has a substantially flat slope indicates opening of natural fissures in the rock and accelerated leakoff of fracturing fluid, or stable height growth into a barrier. Curve portion 12, which has a positive slope of about one (1), is indicative of the onset of a "screenout" where bridging of a fracture by proppants will restrict further fracture extension. Curve 13 having a constant negative slope shows "KGD" type of behavior of a fracture where the height is greater than the penetration distance of the fracture into the formation, or a radial, penny-shaped fracture. The plots shown in FIG. 1 are the so-called "net pressure" plots and are well known in the art as a diagnostic tool for interpretation of fracturing pressure data. The pressure data can be measured during the fracturing operation in any suitable manner, for example by use of a downhole pressure gauge, or a dead string for measuring surface pressures that are representative of downhole conditions. The pressures also can be inferred from surface measurements of injection pressures, taking into account the friction losses in the pipe, and the hydrostatic head pressure. Thus, the term "measuring" as used herein and in the claims is intended to encompass any procedure whereby the pressure data is obtained.
The basic relationship for the PKN, and the KGD or radial fracture geometrics shown in FIG. 1 can be written as:
Pw-Pc=At.sup.b (1)
Where
A=constant of proportionality
Pw=pressure in the well bore, psi
Pc=closure pressure, psi
t=time since initiation of fracture, min.
b=slope
Taking the derivative of Equation (1) yields: ##EQU1## Multiplying Equation (2) through by t gives: ##EQU2##
It therefore follows that a log-log plot of the left-hand side of equation (3) versus pumping time will yield the same slope b as in equation (1), the net pressure plot. However, knowledge of the actual closure pressure, which essentially is constant is not necessary. In the absence of an independent measurement of the closure pressure, the slope of the derivative values can be used to estimate closure pressure by finding the value that will yield an equal slope for the corresponding net pressure plot. This effect is illustrated in FIG. 2 where curve 15 will result if closure pressure is underestimated, curve 16 will result if closure pressure is overestimated, and curve 17 which is parallel to the derivative plot 18 will result where the estimated closure pressure value is correct. It can be seen from FIG. 2 that an incorrect value for the closure pressure has a significant effect on the net pressure plot, while the derivative stays the same. The effect of constant friction losses in the casing or tubing also are eliminated, since the derivative is a measure of rate of change.
Provided the fracture is propagating with height confinement, or radially, the logarithmic derivative values of the pressure will display a straight line 18 having a slope of a certain value. As noted above, the minimum in-situ stress can then be determined by choosing a closure pressure value that, when subtracted from the fracture pressures, yields a log-log straight line 17 of equal slope. It will be apparent that the use of derivative values in accordance with this invention makes the choice of the closure pressure value that is actually used unimportant, since the derivative is unaffected thereby.
Fracture extension with height confinement (PKN behavior) can be readily identified from the plot according to the present invention, and is characterized by the net pressure plot 17 and the derivative plot 18 displaying parallel straight lines that have a small positive slope, generally between 1/4 and 1/8. Parallel straight lines with a small negative slope indicates either fracture height confinement for a height greater than three (3) times its penetration distance into the formation, or a radial, penny-shaped fracture. A flat derivative, that is where the slope approaches zero, indicates a stable height growth through a barrier, or possibly natural fissures that are opening and thereby accelerating leak-off.
FIG. 3 illustrates the foregoing effect and shows that the net pressure plot 20, alone, would have suggested fracture extension with height confinement. However the derivative plot 21, being approximately constant, shows clearly that a stable height growth, or fissures opening, is in fact taking place. The recognition of this through use of the present invention is important, as it gives a clear and early warning that the pressure capacity of the formation may be reached during the fracturing operation which will result in inefficient fracture extension, and a possible screenout, which would have a detrimental effect on the economics of the well unless corrective action is taken once the behavior is recognized from the essentially flat portion 21 of the derivative plot.
Another important fracturing event that can be recognized early in accordance with the present invention is screenout. The use of the derivative provides enhanced sensitivity, and detects events earlier in time than is possible through the use of the net pressure plot alone. As shown in FIG. 4, a fracture tip screenout can be recognized when the derivative increases sharply in the curve portion 25, well before this phenomena can be observed on the net pressure plot 26. At a later time, the derivative and net pressure values tend to merge in the region 27. For a near well bore screenout, FIG. 5 shows that the derivative increases sharply in the region 28, and then crosses the net pressure plot 29 at 30, which again identifies the screenout earlier than by using the net pressure plot alone. The lead time obtained in accordance with the present invention is highly advantageous in that corrective actions can be taken to minimize the economic impact of a screenout.
The use of the derivative of the pressure data clearly magnifies and permits detection of events earlier in time than prior methods due to the enhanced sensitivity. To further illustrate the derivative approach, a diagnostic plot is shown in FIG. 6 of net pressure, and the pressure derivative, made from actual field data. The plot indicates "PKN" behavior of the fractures in the region 30 of the plot for about the first six (6) minutes of pumping. The closure pressure is determined by making the slope of the net pressure data in the PKN region equal to that of the plot of the derivatives. The estimate was found to coincide with the results of an in-situ stress test that was conducted prior to the job. The net pressure data exhibits a flattened aspect 32 that is evident after about 20 minutes of pumping, while the injection rate was maintained constant. This pattern indicates increased fluid loss due to opening of natural fissures in the rock, or stable height growth. The pressure at which this phenomenon occurs its known as the pressure capacity of the formation. Detection of such capacity is crucial for an adequate design of a fracturing operation. Pressures are then kept, if possible, below the critical value which would otherwise increase leakoff, decrease the efficiency of fracture extension, and possibly result in an early screenout by premature slurry dehydration. Of extreme importance in connection with the present invention is the fact that the derivative detects the departure from the PKN-type behavior earlier in time. For example the derivative slope flattens in the region 33 after about 7 minutes, and a definite downward trend 34 can be seen at about 12 minutes. This lead time can be used to great advantage in making on-the-spot decisions during the fracturing operation.
The plots as disclosed herein can be made by machine in real time upon receipt of downhole pressure measurements, and then an interpretation made in accordance with the present invention upon observation of the trends of such plots. Alternatively, the interpretation also can be made by machine computation with a suitable display of the diagnosis. Either procedure is intended to be within the scope of the present invention.
It now will be recognized that new and improved methods have been disclosed for analysis of the pressure data that is obtained during a well fracturing operation. As mentioned previously, the data can be obtained by direct downhole measurements, or can be inferred from surface measurements, taken together with other factors such as friction losses and hydrostatic head. Since certain changes or modifications may be made in the disclosed methods without departing from the inventive concepts involved, it is the aim of the appended claims to cover all such changes or modifications falling within the true spirit and scope of the present invention. | In accordance with illustrative embodiments of the present invention, a method of determining fracture behavior from downhole pressure measurements that are made during a hydraulic well fracturing operation includes pumping fracturing fluids at a constant rate under high pressure against a formation to create fractures therein, and obtaining measurements representative of downhole pressures as pumping progresses. The logarithmic derivatives of such pressure measurements are used to determine the type of fracture behavior, as well as the onset of screenout where the fracturing fluid carries a proppant. In-situ stress or closure pressure also can be determined by finding a value thereof which makes a logarithmic net pressure plot have the same slope as the logarithmic plot of the values of the pressure derivatives. | 4 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a process for removing tar from a spent acid. The present invention further relates to a process for removing by-product tar during the manufacture of isopropyl alcohol and methyl ethyl ketone.
[0003] 2. Description of the Prior Art
[0004] Acids have been used in industrial hydrocarbon refining processes. For example, in indirect hydration processes for manufacturing isopropyl alcohol (IPA) and methyl ethyl ketone (MEK), concentrated sulfuric acid (e.g. 60% to 95% by weight) is employed as a catalyst for reactants. For economic reasons, sulfuric acid is captured and reused in the process. The sulfuric acid to be reused is in a dilute form referred to in the industry as “spent acid.” The spent acid is refined or concentrated by boiling off water, typically in a heater or heat exchanger.
[0005] A common problem encountered during the concentration of spent acid is the fouling of heater or heat exchanger surfaces. Fouling comes from the presence of dispersed tar, a reaction by-product, in the spent acid. Fouling necessitates more frequent cleaning and maintenance of the heat exchanger and reduces heat exchange efficiency.
[0006] U.S. Pat. No. 4,406,760 relates to the use of electrolytic process for treating sulfuric acid streams. Impurities are electrolytically oxidized. A disadvantage of the electrolytic process is the formation of hydrogen bubbles, which causes industrial hygiene and safety concerns.
[0007] Ind. Eng. Chem., Process Des. Dev., vol. 16, No. 4, 1977, discloses the use of air sparging with cationic/nonionic surfactants to separate low viscosity oil dispersions from water and sea water.
[0008] U.S. Pat. Nos. 5,080,802 and 5,156,745 disclose the use of a gas-producing eductor and coalescer to separate oil and particulate matters from liquids.
[0009] It would be desirable to have a process for removing tars from spent acid. It would further be desirable to have a process for removing tars from spent acid in indirect hydration processes for manufacturing IPA and MEK.
SUMMARY OF THE INVENTION
[0010] It is an object of the present invention to have a process for removing tar from spent acid.
[0011] It is an object of the present invention to have a process for removing by-product tar from spent acid in the manufacture of IPA and MEK.
[0012] According to this and other objects of the present invention, there is a process for removing by-product tar during the manufacture is isopropyl alcohol. The process comprises the following: a) reacting propylene with concentrated sulfuric acid and water to form isopropyl alcohol and a spent acid having a by-product tar therein; b) capturing at least a portion of the isopropyl alcohol; c) contacting the spent acid with a gas in bubble form; d) allowing a least a portion of the tar to separate from the remainder of the spent acid to form a layer of tar and a layer of cleaned acid solution; e) capturing tar from the tar layer and disposing of it; f) capturing cleaned acid solution from the cleaned acid solution layer; and g) recycling the cleaned acid solution to step a) as a source of acid.
[0013] Still further according to this and other objects of the present invention, there is process for removing by-product tar during the manufacture of methyl ethyl ketone. The process is substantially the same as the foregoing except that 1-butene is substituted for propylene.
[0014] Yet further according to this and other objects of the present invention, there is a process for removing tar from a spent acid. The process has the following steps: i) contacting the spent acid with a gas in bubble form for a time period sufficient to contact the tar; ii) allowing a least a portion of the tar to separate from the remainder of the spent acid to form a layer of tar; and iii) capturing the tar.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] [0015]FIG. 1 is a cross-sectional view of yet another embodiment of a gas sparging separation module useful in the process of the present invention. The separation module was employed in Examples 1 and 2.
[0016] [0016]FIG. 2 is a micrograph (500×) of spent acid before cleaning in Example 1.
[0017] [0017]FIG. 3 is a micrograph (500×) of spent acid after cleaning in Example 1.
[0018] [0018]FIG. 4 is a micrograph (500×) of spent acid before cleaning of Example 2.
[0019] [0019]FIG. 5 is a micrograph (500×) of spent acid after cleaning in Example 2.
[0020] [0020]FIG. 6 is a micrograph (500×) of spent acid before cleaning in Example 3.
[0021] [0021]FIG. 7 is a micrograph (500×) of spent acid after cleaning of Example 3.
[0022] [0022]FIG. 8 is a schematic diagram of an indirect hydration process in accordance with present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0023] It was found surprising that tar could be removed from the spent acid. It was also found surprising that by-product tar could be removed during the manufacture of MEK and IPA. Tar is removed by introducing into the spent acid a gas such that it is dispersed in the form of bubbles. The bubble contact the by-product tar and cause it to float and separate as a layer floating on the spent acid. The floating layer is captured and otherwise disposed of. The remainder of the spent acid, the cleaned acid solution, is returned in the manufacturing processes as a source of acid. If desired, the cleaned acid solution can be boiled in a heater or heat exchanger to concentrate the acid prior to reuse.
[0024] A gas is introduced into the spent acid in the form of bubbles to effect separation of the tar dispersion from the other components of the spent acid. The gas may be introduced into the spent acid by any means known in the art, such as injection or by vacuum. One means for introducing the gas is an eductor, which employs the flow of spent acid therethrough to create a vacuum that draws gas into the spent acid. A preferred means for introducing the gas is blowing the gas through a gas sparger. The size of the bubbles introduced is preferably microscopic, which is typically about 3000 microns or less and most typically about 100 to about 300 microns in diameter. The bubbles are dispersed and allowed to contact the by-product tar for a time period sufficient for tar separation and formation of a tar layer on top of the spent acid. The separation can be carried out over a wide range of temperatures, e.g. typically up to about 350° F. and more typically about 100° F. to about 350° F.
[0025] Virtually any gas is useful in the present invention so long as it does not react or cause undesirable chemical byproduct reactions with the spent acid. Useful gases include nitrogen, carbon dioxide, argon, and air. Nitrogen is a preferred gas.
[0026] After the gas is introduced into the spent acid, the spent acid may optionally be passed through a static or dynamic mixer, to ensure a substantially homogeneous dispersion of bubbles therein.
[0027] After introduction of gas bubbles, the spent acid having the dispersed gas bubbles therein is allowed to settle to effect separation of the spent acid into a layer or phase of tar and a layer or phase of a cleaned acid solution. Such separation is typically carried out by conveying the gas-laden spend acid to a tank or other container vessel. The retention time of the gas-laden spent acid in the tank or vessel is regulated such that such layering or phase separation has sufficient time to occur. An advantage of the present invention is that separation can take place without the introduction of a surfactant, e.g., a cationic surfactant or a nonionic surfactant, into the spent acid. If desired, a surfactant may be introduced.
[0028] The tar layer can be captured or removed from the spent acid by any means know in the art, such as filtration, runoff/overflow trough or paddle action. The cleaned acid solution is then returned as a source of acid or may be concentrated by removal of water by boiling in a heater or heat exchanger and then recycling. The tar layer may be disposed of or regenerated to yield sulfuric acid by means known in the art. One means for regenerating sulfuric acid from the tar layer is to fluidize the tar by adding dilute sulfuric acid and a optionally a surfactant. The fluidized tar is incinerated to yield sulfur dioxide. The sulfur dioxide is converted to sulfur trioxide, which is contacted with dilute sulfuric acid to form more concentrated (more enriched) sulfuric acid for reuse as a source of concentrated sulfuric acid. Alternately, the sulfur trioxide may be contacted with water to produce sulfuric acid for reuse. Additional teachings regarding the fluidization and conversion of tar to sulfuric acid are shown in 6,197,837 and 6,245,216, which is incorporated herein by reference.
[0029] Spent acid may have acid-soluble hydrocarbons dissolved therein and acid-insoluble tars dispersed therein. The present processes can remove a portion of or substantially all the acid-insoluble tars. Prior to treatment (cleaning), the spent acid is typically dark, opaque and tarry in appearance. After acid-insoluble tars have been removed, the remainder of the spent acid is a cleaned acid solution that is substantially lower in tar content.
[0030] Examples of useful commercial separation modules include the Wemco Duperator 1+1 (Baker Hughes Process Systems), ISF-Induced Static Flotation Cell (Baker Hughes Process Systems) and Unicell Vertical IGF (Unicell Technologies).
[0031] Flocculating agents or absorbent particles optionally may be employed in the present invention to assist in the removal of tar. Absorbent particles are particularly useful. Absorbent particles may be used in an amount and for a period of time sufficient to contact and absorb additional tar from the spent acid. Typically, the amount of absorbent particles used will be about 0.1 wt % or more, preferably about 0.25 weight percent (wt %) to about 5.0 wt %, more preferably about 0.50 wt % to about 3.0 wt %, and most preferably about 0.50 wt % to about 2.0 wt 5 based upon the weight of the spent acid. Useful absorbent particles are carbon black and fumed silica. Carbon black is preferred. Preferred carbon blacks are industrially reinforcing carbon blacks and are activated. Useful carbon blacks have a nitrogen surface area/weight ratio of about 20 to about 700 m 2 /gram, preferably about 70 to about 350 m 2 /gram and most preferably about 80 to about 250 m 2 /gram. Useful fumed silicas may have hydrophilic (Cab-O-SIL TS-720 by Cabot) or hydrophobic (Cab-O-SIL TS-720 by Cabot) or equivalent surfaces. Preferred surface area/weight ratios are about 100+/−20 m 2 /gram. As needed, filtration and/or centrifugation may be used to separate tar-laden absorbent particles from spent acid and/or tar sludges.
[0032] The present invention is particularly useful in cleaning by-product tar from conventional indirect hydration processes for manufacturing isopropyl alcohol (IPA) and methyl ethyl ketone (MEK).
[0033] In the manufacture of IPA, propylene is reacted with concentrated aqueous sulfuric acid and water in sequence to form IPA and an acid-containing by-product tar dispersion referred to as spent acid. After the first reaction with concentrated sulfuric acid, propylene is converted to propyl sulfate esters. The sulfates are then reacted with water to form IPA. The water reaction is usually carried by steam stripping, which also functions to separate the IPA in an overhead vapor steam. Numerous by-products can be formed, including tar, diisopropyl ether, acetone, propionaldehyde, and polymers of propylene, and IPA. By-products can be present in the overhead vapor stream or in the stripper bottoms (liquid stream from stripper). The spent acid typically comprises acid-soluble hydrocarbons and acid-insoluble mixed tars present in the stripper bottoms in the form of a dark dispersion. The spent acid has a brown/black coloration and is usually opaque. Sulfuric acid is present at dilute levels in the spent acid because water has been previously added for the hydration reaction. For reasons of economy, it is desirable to reuse the spent acid by removing tar and processing it to a more concentrated form so that it can be returned for use in reacting with propylene in the first reaction step. Tar is removed from the spent acid in accordance with the methods described herein. Tar removal from the spent acid ensures that fouling in the heater or heat exchanger is reduced or substantially reduced. The resulting cleaned acid solution is then concentrated and returned as a source of acid for the process. Optionally, the tar may be fluidized and thermally treated or regenerated into concentrated acid according the methods known in the art. Additional teachings to the indirect hydration process for manufacturing IPA are set forth in the Encyclopedia of Chemical Technology, 3 rd Ed. Vol. 19, pp. 198-220, which is incorporated herein by reference.
[0034] The manufacture of MEK is carried out in a manner substantially the same as the manufacture of IRA except the 1-butene is substituted for propylene. The Shell-Dominguez process is an example of an indirect hydration process for manufacturing MEK. Reaction by-products include tar, butadiene, polybutadiene, 4-vinyl-1-cyclohexene and 4-phenylcyclohexene. Additional teachings to the process are set forth in the Encyclopedia of Chemical Technology, 3 rd Ed. Vol. 12, pp. 133.
[0035] A general indirect hydration process is shown schematically in FIG. 8 and is generally referenced by the numeral 100 . Concentrated sulfuric acid in conduit 104 is conveyed to absorber 108 , where a hydrocarbon feedstock is added via conduit 112 . The hydrocarbon feedstock absorbs into the concentrated sulfuric acid in absorber 108 and is conveyed to stripper 114 via conduit 110 . Water is added to stripper 114 via conduit 116 . The hydrocarbon feedstock reacts with the water to form a product hydrocarbon; which exits stripper 114 via conduit 118 . Spent acid exits the bottom of stripper 114 and is conveyed via conduit 118 to separation module 120 . In separation module 120 , microscopic bubbles are employed to separate the tar from the remainder of the spent acid. Tar is captured via conduit 122 and stored for subsequent fluidization and thermal regeneration. The remainder of the spent acid takes the form of a cleaned acid solution, which exits module 120 via conduit 126 . Makeup concentrated sulfuric acid is added to conduit 126 via conduit 128 to form conduit 130 , which leads to heater 134 . The cleaned acid solution is heated in heater 134 to drive off part of the water therein to re-concentrate the sulfuric acid. The sulfuric acid concentrate is conveyed to a flash drum 140 via conduit 136 . Flash drum 140 lowers the temperature of the boiling acid, removes water vapor and further concentrates the cleaned acid solution. The acid concentrate bottoms from flash drum 140 , are conveyed to cooler 144 via conduit 142 . Cooler 144 cools the acid concentrate, which is conveyed to a purge tank 150 . In purge tank 150 , any remaining insoluble tar in the concentrate is allowed to float in a layer 152 , on top of the cleaned acid solution layer 154 . The acid concentrate is then conveyed to absorber 108 via conduit 104 , which was also discussed above. As necessary, floating tar or excess concentrate may be removed from purge tank 150 via conduit 156 .
[0036] In the following examples all percentages or parts are by weight unless indicated otherwise.
EXAMPLES
[0037] The process of the present invention was used to clean MEK spent acid samples in different separation modules under different temperature conditions. One test was conducted in glass/Teflon™ (polytetrafluoroethylene) separation module at 140° F. to 170° F. (Example 1), a glass/Teflon™ separation module at around 306° F. (Example 2) and a glass sparger separation module at 320° F. (Example 3). Teflon™ is a trademark of E.I. duPont de Nemours & Co.
EXAMPLES
Examples 1 (Medium Temperature 140° F. to 170° F.)
[0038] The test in Example 1 was conducted with a Glass/Teflon™ separation module, which is generally referenced by the numeral 70 in FIG. 1. Warm spent acid (140° F. to 170° F.) is introduced into glass jar 74 up to a level of a filter paper 80 , which is doughnut-shaped and composed of glass fiber. Nitrogen gas is introduced into the spent acid through a tube 76 and a gas sparger 78 having 20-50 micron holes to form microscopic gas bubbles. Tar dispersion adheres with these gas bubbles and rises inside column 75 into the glass spheres 88 . Column 75 has a doughnut-shaped perforated Teflon™ plate 82 designed to support glass spheres 88 as well as to allow gas bubbles and tar to pass through. The tar layer floats over spheres 88 and out onto-glass fiber paper 80 . The cleaned acid is collected from column 75 . The thick tar layer has a viscosity of over 10,000 centipoise (Brookfield viscometer at 77° F.).
[0039] Samples of the cleaned acid solution were taken at outside of column 75 at time zero and at 6 minutes of module operation. Percent carbon were tested using the Leco CHN(carbon, hydrocarbon and nitrogen) instrument, % acid were tested by titration and percent (%) water were determined using the potentiometric technique using the 701 KF Titrino tester (Ace Glass Inc.).
TABLE 1 Tar Separation using Glass/Teflon ™ Module at 140° F.-170° F. Sample % acid % water % carbon 0 minute control 48.1 51.9 0.56 @6 minute 48.2 51.4 0.20
[0040] The percent (%) carbon in the treated 6-minute sample is significantly less than for the untreated control sample. Micrographs (500×magnification) of the control sample and the 6 minute sample can be seen in FIGS. 2 and 3, respectively. Comparing FIGS. 2 and 3, the amount of tar dispersion in the cleaned sample is visibly lower. The cleaned acid is less turbid reflecting reduced amount of tar dispersion.
Example 2 (High Temperature-360° F.)
[0041] The test in Example 2 was conducted with the same separation module (glass/Teflon™ unit) as in Example 1 and was conducted in substantially the same manner as Example 1 except for a different operating temperature.
[0042] Column 75 was placed in jar 74 and the jar 74 preheated to 306° F. In a separate jar heated to 306° F., the spent acid and a small amount of tar were mixed together rapidly and added to jar 74 . A loose layer of tar was noticed to form rapidly on the surface. Samples were collected near the top and around the middle level of jar 74 . Nitrogen gas was passed through sparger 78 at 2 standard cubic feet per hour and cleaned acid samples were collected near the bottom of module 74 at 2 and 5 minutes after initiation of gas flow. Filter paper 78 was placed on top of the glass spheres 88 to collect the tar being separated. A sample was collected at the tar level and at the bottom of jar 74 for the time 0 to time 5 minute samples. The percent carbon, acid, and water for the samples were tested.
TABLE 2 Tar Separation using Glass/Teflon ™ Module at 306° F. Sample % acid % water % carbon Top Tar Rich Layer 60.1 38.6 1.04 0 minute sample 61.1 38.4 0.27 2 minute sample 61.7 37.9 0.28 5 minute sample 61.5 38.1 0.19
[0043] The initial top tar layer sample had the highest tar content (1.04%) even before the nitrogen sparging was started. The control sample (0-minute) was down to 0.27% carbon shortly before sparging was started. The carbon content was unchanged after 2 minutes of sparging but was down to 0.19% after 5 minutes. The heaviest tar dispersion was seen to collect quickly at the top (FIG. 4) whereas the tar droplets collected near the bottom were noticeably smaller for the 5 minute sample (FIG. 5).
Example 3 (gas sparging at 320° F.)
[0044] This test was conducted with a separation module different than the module employed in Examples 1 and 2. A glass jar was preheated to 320° F. and warm spent acid (@130° F.) was poured into jar 74 jar. The spent acid was heated to 320° F. under constant stirring. As soon as the equilibrium temperature was reached, nitrogen gas was injected through a glass sparger into the bottom of the jar at about 2 cubic feet/minute. Samples were collected at 0, 5 and 10 minutes at the bottom of jar 74 . Results are set forth in Table 3.
TABLE 3 Tar Separation using Glass Sparger at 320° F. Time of Sample (minutes) % Carbon 0 0.5 5 0.35 10 0.32
[0045] The initial 0 minute sample exhibited the highest carbon level, whereas the carbon level of the 5 and 10 minute were lower. The 0 minute sample exhibits more visible tar dispersion (FIG. 6) than the 5 minute sample (FIG. 7).
[0046] It should be understood that the foregoing description is only illustrative of the present invention. Various alternatives and modifications can be devised by those skilled in the art without departing from the invention. Accordingly, the present invention is intended to embrace all such alternatives, modifications and variances that fall within the scope of the appended claims. | There is a process for removing by-product tar during the manufacture of isopropyl alcohol. The process comprises the following: a) reacting propylene with concentrated sulfuric acid and water to form isopropyl alcohol and a spent acid having a by-product tar; b) capturing at leas a portion of the isopropyl alcohol; c) contacting the spent acid with a gas in bubble form; d) allowing a least a portion of the tar to separate from the remainder of the spent acid to form a layer of tar and a layer of cleaned acid solution; e) capturing the tar; and h) recycling the cleaned acid solution to step a) as a source of sulfuric acid. There is also a process for removing by-product tar during the manufacture of methyl ethyl ketone. The process is substantially the same except that 1-butene is substituted for propylene. There is also a process for removing tar from a spent acid. | 2 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a continuation of U.S. application Ser. No. 13/051,021, filed Mar. 18, 2011 and now issued as U.S. Pat. No. 8,082,281, which is a continuation of U.S. application Ser. No. 12/566,708, filed Sep. 25, 2009 and now issued as U.S. Pat. No. 7,933,931, which is a continuation of U.S. application Ser. No. 10/422,815, filed Apr. 25, 2003 and now issued as U.S. Pat. No. 7,617,248, which is a continuation of U.S. application Ser. No. 09/468,930, filed Dec. 22, 1999 and now issued as U.S. Pat. No. 6,587,851, with all incorporated herein by reference in their entirety.
BACKGROUND
1. Field of the Invention
The present invention is directed to a system and method for notifying and dispatching employees. The notification system and method of the present invention may also be used as an accessory or addition to existing dispatch systems.
2. Background of the Invention
Existing employee dispatch systems and methods include either a dispatcher (a person who receives and processes requests for services), or an automated dispatch system. These existing dispatch systems suffer from shortcomings and limitations that significantly detract from their usefulness and their efficient management of resources.
The limitations of current dispatch systems can be demonstrated by considering an example of a large public utility, such as a local telephone company that provides telephone services. Local telephone companies typically have tens of millions of customers, and those customers request new services or changes in services. These requests require the telephone company to dispatch technicians to service locations to make the requested changes in service.
On average, a local telephone company will make two and a half to three million service order dispatches per year. Generally, the productivity per task is about 2 hours, in other words, the requests for service generally take 2 hours to resolve. With this level of productivity, the local telephone company can only assign around four items per day per technician. Thus each truck dispatch is extremely costly to the local telephone company. It therefore becomes imperative that each dispatch is effective, i.e., each dispatch either actually resolves the problem or obtains information needed to resolve the problem.
Conventional automated dispatch systems very often assign tasks on a first-come, first-serve basis to the first available technician. As a technician completes or close out a job, the next job in the queue is automatically assigned to that technician. Occasionally, by happenstance, this first-come first-serve priority system would produce efficiencies where a second job would come to the technician after the first job was completed and the second job would happen to be in the same location as the first job. This would allow the technician to quickly complete a second job without having to drive to another location. Unfortunately, these efficiencies seldom occur and then only by pure chance. Oftentimes, in fact, that was not the case, and it would be very likely that a technician would leave the first location to travel to the next job site and a second technician would drive up to that first location to complete a second job there.
Moreover, in some cases a single problem causes multiple customers to lose service or experience poor service. For example, damage to pedestals that provide telephone service to multiple customers could cause several customers to report problems or loss of service. The pedestal often is located on the side of the road and provides a connection between a customer's location and serving centers. These pedestals are subject to damage, for example, from cars or even from state highway mowers. When damage to these pedestals occurs, the result is often that multiple outages occur in one locality. Generally, conventional reporting and dispatch systems address this problem by setting a certain tolerance threshold to indicate a probable common problem. For example, if the threshold were set at five, the system would require five or more similar complaints or reports of problems received from a common location to assume that a common problem was causing all of the problems reported by customers. If that threshold number of complaints or reports were met, then only a single technician would be dispatched to resolve the problem.
However, in those cases where the threshold for a system wide or regional problem is not met, as many (in the example provided above) as four technicians may be deployed to a single site causing enormous waste of resources and extreme expense to the company.
Also, customers often cancel appointments or request a modification in service. Sometimes these changes can occur at the last minute and existing systems have no way of informing the technician of these changes. These cancellations and modifications also waste technician resources, because technicians waste time waiting for customers or are required to return to the same location to make the modifications in service that the customer later requested.
Another source of ineffective use of technician resources is the lack of knowledge of customer service representatives. These representatives often lack an understanding of the costs associated with technician deployment and of the logistical complexities of managing and assigning a large number of technicians.
They are generally trained to meet the customer's needs and to generate service orders. However, customer service representatives may occasionally create two different service orders for related or similar tasks. This could cause two dispatches to be generated and result in two technicians being deployed to the same location to fix what the service representative thinks are two different problems, but is instead only a single problem that could be handled by a single technician.
Dispatch systems that use a human dispatcher may permit real time modification of tasks and assignments. However, these dispatch systems, generally employed by taxicab companies, suffer significant drawbacks that would prevent them from being employed in large-scale environments. These dispatcher-based dispatch systems rely on a human dispatcher who is given information regarding demand (customers that need rides). The dispatcher uses this information combined with his or her knowledge of where all of the cabs are to assign the customer pick up to the nearest available cab. First, these dispatch systems are very expensive because a staff of well trained dispatchers are required to work around the clock, 24 hours a day, to match resources with demand. Second, the dispatcher-based systems are not practical for large-scale deployment because human dispatchers cannot accurately track hundreds, much less thousands, of technicians and their daily assignments. Finally, human dispatcher-based systems rely heavily dependent on the performance of the dispatcher or the dispatcher staff.
Human error may produce an unacceptable level of errors.
Thus there is currently a need for a system that accommodates real time or near real time changes in load or demand by adjusting or reallocating resources to meet those changing needs. There is also need for such a system that is also automated, can handle a large number of technicians and requests for services, and inexpensively delivers information to the technician.
SUMMARY OF THE INVENTION
The present invention is designed to overcome the shortcomings of the prior art and to provide an effective and efficient dispatching system that can adjust resources to meet and accommodate real time changes in demand or load. The invention provides a system that notifies technicians of real time changes in their scheduled work. The system can determine if a real time intervention in a technician's schedule is necessary and can notify the technician in near real time of changes in assigned tasks. In this way, the invention adjusts the allocation of resources to meet real time changes in demand.
Once a technician has been dispatched to complete a task, the system monitors cancellations and changes that may be requested by the customer for that task. The system sends information to adjust the assignment of the technician to efficiently utilize the technician's time in situations where the customer has requested late or last minute cancellations or changes.
The system allows real time or near real time instructions to be sent to the technician. These instructions can include changes or modifications to the task assigned to the technician. The instructions can also include notices that the task has been canceled, or that the technician should complete the assigned task and then remain at that location to receive the next assignment.
The invention may include a system that considers the following information in determining if a real time intervention is necessary: information regarding the work history of the technician or the number of hours the technician has worked in a pay period, including the number of overtime hours, the availability of the technician, the qualifications of the technician, and the suitable locations where the technician is most beneficially dispatched.
An object of the present invention is to reduce or eliminate the inefficient use of technicians.
Another object of the present invention is to maximize the utilization of technicians.
Another object of the present invention is to provide a system that adjusts and reallocates resources to meet real time changes in load or demand.
Another object of the present invention is to provide real time or near real time information to a technician regarding the status of his assignments.
Additional features and advantages of the invention well be set forth in the description which follows, and in part will be apparent from the description, or may be learned by practicing the invention. The objectives and other advantages of the invention will be realized and attained by the structure particularly pointed out in the written description and claims as well as the appended drawings.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a schematic diagram of a preferred embodiment of the present invention.
FIG. 2 is a schematic diagram of another preferred embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 shows a schematic representation of a preferred embodiment of the present invention. When a problem 102 arises and is reported to a notification system 104 , according to the present invention, notification system 104 reviews the qualifications of a number of technicians 106 , and selects the most suitable technician 108 to dispatch to the problem 102 .
Once the suitable technician 108 has been dispatched or is en route 110 to the problem, the invention allows real time or near real time instructions to be sent to the technician. These instructions can include changes or modifications to the task assigned to the technician 108 . Preferably, those instructions also include notices that the task technician 108 is currently heading towards has been canceled, or that the technician should complete the assigned task and then remain at that location to receive the next assignment.
In a preferred embodiment, the system 104 includes information regarding the work history of the technician or the number of hours the technician has worked in a pay period, including the number of overtime hours, the availability of the technician, the qualifications of the technician, and suitable locations to which the technician is most beneficially dispatched. In addition to considering all of these factors in deciding to send information to the technician 108 , the system 104 also monitors problem information and requests for service sent to the system by customers and customer service representatives. The system 104 analyzes requests for modifications to existing assignments and determines if a real time intervention is required. If a real time intervention is required, the system 104 sends a message to the technician 108 and informs the technician 108 of that information.
FIG. 2 is a preferred embodiment of the present invention in which various components have been assembled and linked together to provide a notification system 200 . The notification system 200 includes a dispatch unit 202 , a centralized call-out system (CCS) 206 , an employee scheduling program (ESP) 208 and a paging system 210 . The system 200 can communicate with various other devices, for example, an access unit 204 via access system 203 and pagers 212 via paging system 210 .
The dispatch unit 202 serves several functions. Dispatch unit 202 , according to this embodiment, receives information 201 about problems or requests for service from customers directly or through customer service representatives. These problems could include reports of downed lines, loss of service, poor service and other problems that affect the services rendered. Examples of requests for service include requests to modify or change the services rendered. In the specific context of a local telephone company, this could include requests to add additional telephone lines, to add DSL lines, to install additional telephone jacks, and other types of service. Preferably, the dispatch unit 202 receives information regarding problems or requests for service through customer service representatives who complete an interactive computerized form. Preferably, this information, which may include the customer's name, address, telephone number, billing information, and nature of problem, is communicated to the dispatch system 202 when a technician intervention is required.
Dispatch unit 202 communicates with one or more access units 204 via an access system 203 . The access system 203 , which is capable of wireless or wireline communications with access units 204 , also communicates with dispatch unit 202 .
The access system 203 conveys information from the access units 204 to dispatch unit 202 . In an exemplary embodiment of the present invention, the Tech Plus system is used as the access system 203 . The Tech Plus system is disclosed in U.S. patent application Ser. No. 09/343,815, which is assigned to the same assignee as the present application, and is incorporated by reference herein. The access units 204 are preferably each associated with a technician. Preferably, each technician is assigned an access unit 204 and can use the access unit 204 to communicate with the dispatch unit 202 . For purposes of clarity, this disclosure will describe a single access unit 204 , but it should be kept in mind that many other access units 204 may be in communication with dispatch unit 202 . Dispatch unit 202 sends information regarding work assignments to the access unit 204 via access system 203 , which is capable of wireless or wireline communication with access unit 204 . In an exemplary embodiment of the invention, the dispatch system 202 is an LMOS™ (Loop Maintenance Operating System) created by Lucent Technologies.
Dispatch system 202 sends assignment information to access unit 204 via access system 203 and technicians use access unit 204 to retrieve assignment information. Access unit 204 is preferably equipped with a display 220 and an input portion 222 . Preferably, only one assignment is sent to the access unit 204 at a time and a second assignment is only sent after the first assignment has been completed or closed by the technician. Access unit 204 may also include provisions that allow technicians to retrieve infrastructure information. For example, in the context of a local telephone company, infrastructure information could include the number of lead pairs available to a particular location, the number of switches available and other information related to infrastructure. Access unit 204 may also include provisions that allow technicians to run tests on the customer's equipment.
The employee scheduling program (ESP) 208 communicates with dispatch unit 202 and centralized call-out system (CCS) 206 . ESP 208 contains a database that associates each technician with an employee or technician number and a system number. Preferably, the system number is an LMOS™ system number.
The use of a system number is optional, but may be helpful where systems allow only three digit employee numbers and those same employee numbers must be used over again for different employees in different regions. Adding a regional designation or a system number allows each employee to have a unique identification. ESP 208 also includes a detailed database that contains schedule information for some or all of the technicians. ESP 208 preferably stores the scheduling information for all or some of the technicians for up to one year.
Maintenance personnel preferably maintain, enter, and modify the schedules of technicians using the ESP 208 .
ESP 208 provides information regarding the availability of technicians to dispatch unit 202 . Preferably, ESP 208 provides technician numbers, system numbers, and scheduling information to dispatch unit 202 . The dispatch unit 202 preferably stores a detailed, but shorter time span of information regarding scheduling. While the preferred ESP may store a year of scheduling information, the preferred dispatch unit 202 may store only about three to five days of scheduling information. In addition to providing information to dispatch unit 202 , ESP 208 also provides information to CCS 206 . Preferably, ESP 208 provides technician numbers, system numbers, and scheduling information to CCS 206 .
Once CCS 206 receives information from ESP 208 , CCS 206 constructs a table or database that includes technician numbers, system numbers, pager numbers, and pager types. The pager numbers and pager types that are carried by the technicians are stored in CCS 206 , and CCS 206 associates these pager numbers and pager types with the additional information sent to it by ESP 208 . The pager numbers are associated with pagers worn or carried by technicians. CCS 206 is in communication with both the dispatch unit 202 and a paging system 210 .
In order to maximize the efficient use of resources, namely, the technicians and their time, the system 200 can dynamically adjust technician deployment to accommodate real time changes in load or demand for services. Notification system 200 accomplishes this by rapidly notifying technicians of information that could affect their work schedule as soon as possible, and by diverting technicians away from inefficient situations to locations where their talents and skills will be more effectively utilized. These notices to technicians can occur in near real time and even during the critical period after the technician has been dispatched to a job site.
In order to accomplish this near real time adjustment in technician deployment, system 200 preferably uses a number of different components. The following example of, an adjustment demonstrates how system 200 can dynamically adjust technician deployment in near real time.
Initially, dispatch unit 202 is functioning in its normal routine. It receives problems or requests for service 201 , matches technicians based on the factors mentioned above, then transmits tasks and assignments to access unit 204 via access system 203 . As noted above, the dispatch unit 202 may assign tasks in any suitable manner. However, the preferred method of assignment considers several factors including commitment dates and time, severity of the outage, the revenue generated by the service order, and the availability of a close-by technician.
Technicians are preferably assigned based upon geographic regions, which are areas bound by natural geographic barriers. Technicians who are geographically located closer to the task being the preferred dispatch technician. The technicians read the tasks and drive to those destinations to make the necessary repairs or changes in service. Occasionally, dispatch unit 202 will retrieve additional information from the ESP 208 and update its technician work schedules.
Dynamic adjustments occur when dispatch unit 202 is notified of a modification or change to a technician's schedule, or learns of a situation that could result in more efficient use of resources. Customers sometimes call their customer service representatives to notify them that they need to cancel, postpone or change a work request they had previously submitted. When this occurs, the customer service representative relays the information to dispatch unit 202 .
When the dispatch unit 202 receives the notification that a work request has been changed or modified, the dispatch unit 202 determines if an intervention by CCS 206 would be helpful. Any desired situation or condition that helps to prevent waste of technician resources or maximize technician utilization may be used by the dispatch unit 202 to determine if a CCS 206 intervention would be helpful.
Preferably, a condition where a technician has already been dispatched to a job site to an assigned task combined with a request for modification of that task is the condition used to determine a CCS 206 intervention. After dispatch unit 202 has determined that a CCS 206 intervention would be helpful, dispatch unit 202 communicates appropriate information to CCS 206 so that CCS 206 can provide real time adjustment information to the technician. Preferably, dispatch unit 202 communicates geographic information, that is, where in the service region the technician must go to respond to the request and where the technician is located or assigned; information associated with the technician, like the employee number and the technician's system number; and information related to the modification or change in schedule or task.
This information is used by CCS 206 to determine which technician should receive the information and what information that technician should receive. Once the identity of the technician and the adjustment information to be sent to the technician has been determined, CCS. 206 communicates this information to a paging system 210 . Preferably, the information communicated to the paging system 210 includes the technician's pager number and an information code. CCS 206 can also preferably send a text message, if the technician's pager is capable of receiving text messages.
The paging system 210 receives the information from CCS 206 and sends a page to the technician's pager 212 . After the technician has been paged, the technician can review the information displayed on pager 212 and act accordingly.
Some of the preferred messages that are sent to technicians include codes that inform the technicians that a job has been canceled or modified. Another code that can be sent to the technician informs the technician that the next job will be at the same or nearby location. In essence, this code is a “remain where you are and standby for the next job” command. Obviously, if a customer wants to cancel a previously scheduled service order, the cancel code will be transmitted. Similarly, if a customer wants to change or modify a previously scheduled service order, the change or modify code will be transmitted to the technician. When the technician receives the change or modify code, the technician is preferably trained to retrieve the new job from the access system 204 . Finally, if the system 200 determines that it would be beneficial for the technician to remain at a certain location after a job has been completed, the remain code will be transmitted. In an exemplary embodiment of the present invention, the cancel code is 333 , the modify or change code is 444 and the remain code is 555 .
Any of the various components or sub-steps disclosed above can be used either alone, or with other existing components, or with components or features of the present invention.
It will be apparent to those skilled in the art that various modifications and variations can be made to the dynamic carrier selection system of the present invention without departing from the spirit or scope of the invention.
The foregoing disclosure of embodiments of the present invention has been presented for purposes of illustration and description. It is not exhaustive or intended to limit the invention to the precise forms disclosed herein. Many variations and modifications of the embodiments described herein will be obvious to one of ordinary skill in the art in light of the above disclosure. The scope of the invention is to be defined only by the claims appended hereto, and by their equivalents. | A dispatching system adjusts resources to meet real-time changes in demand. When a customer requests service, a work assignment is generated and sent to an employee. When a customer cancels the requested service, a cancellation code is sent to the employee. The cancellation code informs the employee that the work assignment has been canceled. | 8 |
RELATED APPLICATION
This is a division of application Ser. No. 08/439,059 filed May 8, 1995 now abandoned which is a continuation in part of application Ser. No. 08/333,926 filed Nov. 3, 1994, now U.S. Pat. No. 5,559,624, which itself is a continuation of application Ser. No. 08/029,724 pending, titled "Optical Network Based on Remote Interrogation of Terminal Equipment", filed Mar. 11, 1993 (henceforth, Darcie 8-1-3), which is assigned to the assignee of the instant application and is hereby incorporated by reference.
BACKGROUND OF THE INVENTON
1. Field of the Invention
This invention related to optical communication networks.
2. Description of Prior Art
One approach for creating optical networks involves the use of a passive optical network (PON) in which there are no active components between a hub communication point, such as a central office, and an end communication point, such as a subscriber's terminal equipment. A feeder fiber from the central office provides a downstream optical signal to a remote distribution module, or node, (RN) that splits the optical signal for distribution onto a number of optical fibers, and each of the fibers terminates in an Optical Network Unit (ONU). The latter converts the received optical signal into electrical form and delivers it to either one or a number of subscribers
The Darcie 8-1-3 application discloses a passive photonic loop arrangement where the central office employs wavelength division multiplexing (WDM) to form an optical signal for downstream transmission. That is, the information for each ONU is multiplexed onto an optical signal of the particular wavelength assigned to the ONU, thereby forming an information-bearing optical signal, and the information-bearing optical signals for the other ONUs (each having its own wavelength) are combined to form the WDM signal.
Illustratively, each of the different wavelength signals is generated from a different laser.
The WDM optical signal is received by the RN, where it is demultiplexed into individual optical signals of particular wavelengths and each individual optical signal is then routed to its associated ONU, which may also be wavelength sensitive. The ONU employs a fraction of the received signal to detect the information that the central office was communicating, and employs the remainder of the received signal as a carrier for information that is transmitted by the ONU to the central office. Thus, the ONU does not need to have a light source of its own to serve as a carrier signals. Expressed another way, the central office creates a carrier signal which is used to communicate information downstream (when there is such information to be communicated) and which is also used to communicate information upstream (when there is such information to be communicated). Viewed another way, the central office effectively interrogates each ONU with the downstream optical signal, and allows each ONU to transmit its upstream information.
One feature of the system disclosed by Darcie 8-3-1 allows the use of a time-division multiplexing protocol that is decoupled from, or independent of, the ONU. As a result, the ONU does not have to have any predefined information about the time-division multiplexing protocol. This increases the flexibility of the central office to allocate system resources like bandwidth. Another feature of the system allows the use of subcarrier modulation of the transmitted optical signal to mitigate the effects of optical path delay (e.g., collision) on the upstream optical signal and to permit routing of signals at the ONU and the central office.
In addition, the disclosed system allows the central office to perform enhanced fault detection. In the embodiment described above, for example, there is effectively an unbroken optical circuit from the laser in the central office to an optical receiver in the central office, and this provides the central office with access to the entire optical loop.
In another copending application, Ser. No. 08/366,849, titled "A Passive Optical Network With Bi-Directional Optical Spectral Slicing and Loop-Back", filed Dec. 30, 1994 (Darcie 14-10-3), an arrangement is disclosed where information is transmitted from the ONU to the central office at a wavelength that is different from the wavelength at which information is sent by the central office, but the loop-back to the central office is maintained and it is used for evaluating continuity of the communication path to and from the ONU. This is accomplished by the central office sending a test signal at a wavelength that is different from the normal signal wavelength used to communicate to the ONU and different from the signal wavelength that is used to communicate from the ONU. The ONU loops it back, and the central office detects the returned signal as a confirmation of the path's continuity. Should the signal not return, conventional optical time domain reflectometry (OTDR) techniques may be employed to pin-point the break (or failure of the ONU). OTDR is described, for example, in J. M. Senior "Optical Fiber Communications" pp. 822-827 (Prentice Hall). This application is also incorporated by reference.
While use of a different wavelength for evaluating fiber continuity has certain advantages, there is also an advantage to not using a carrier of a different wavelength for that purpose because, in the latter case, no additional laser is required in the central office. However, it is not desirable to keep a central office carrier signal active all the time, because it consumes power.
SUMMARY
In accordance with the disclosure herein, the desire to confirm continuity of the bi-directional communication path between the central office and ONU is coupled with the process of establishing communication from the ONU and the central office. In the disclosed system, which follows the general mode of operation of the system disclosed in Darcie 8-1-3, when there is no active communication between the central office and the ONU, the central office repetitively sends an interrogation optical pulse to the ONU (at the ONU's assigned wavelength). Those pulses perform two functions: to determine whether the ONU wishes to initiate communication with the central office, and to report to the central office on the continuity of the communications path to and from the ONU.
In the ONU, a modulator whose function is to relay data from the customer's terminal is arranged to operate in two distinct modes. When it is "off", which is when the customer terminal is inactive, it allows central office signals to loop-back to the central office much like disclosed in the Darcie 8-1-3 application. In this state, the optical pulses sent by the central office serve the function of optical continuity checking. When an ONU wishes to establish a connection, i.e., the customer terminal wishes to "make a call", the modulator is arranged to interpose itself in the loop-back path and thereby inform the CO of its desire. One approach for informing the CO that a connection to some remote customer terminal is desired is to temporarily block the path to the central office by placing the modulator within the ONU in a state that prevents the return of the carrier to the CO. This can be done by applying an appropriate modulation signal to the modulator or, in the case of active modulators, by withholding the application of power to the modulator.
When the optical interrogation pulses fail to return to the central office, the central office knows that either the ONU is wishing to make a call, or a break exists in the communications path (the fiber broke, or the ONU failed). To distinguish between the two possible causes, the central office assumes that the ONU is signaling a desire to make a call and responds by sending a carrier signal with information corresponding to a "dial tone" in conventional telephony circuits. When, in fact, the condition is that of the ONU wishing to make a call, the ONU receives the dial tone and responds by reopening the loop-back path to the central office. Consequently, a portion of the dial tone is returned to the central office, the central office detects the returned dial tone, and that serves as a confirmation that the central office's assumption was correct. When the failure of the optical pulse to return to the central office is caused by a system failure, the dial tone is also not returned to the central office and the latter failure serves as notice to the central office that a true failure exists.
The optical communication system of this invention includes a coupler responsive to an input signal arriving at an input port, wherein the signal includes a carrier that is modulated with data. The coupler develops a first signal corresponding to the input signal multiplied by a constant M and a second signal corresponding to the input signal multiplied by a value N. The optical communication system also includes a detector responsive to the first signal and which detects the data, and a processing/control arrangement responsive to the detector. The processing/control arrangement receives the data detected by the detector, applies the signals related to the received data to a data output port, receives signals at a data input port, and outputs the data signals. The optical communications system further includes a modulator responsive to the second signal and to the data signals of the processing/control arrangement, wherein the second signal is modulated with data signals to form a modulated upstream signal which is applied to an output port.
Various other capabilities and features that relate to maintenance, system control, communication control, etc. are disclosed.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a block diagram of a passive optical communications system in accordance with the principles disclosed herein;
FIG. 2 shows time slots, the shallow modulation mode, gaps between time slots, and different data rates in different time slots;
FIG. 3 shows the deep modulation mode that may be employed by ONU 100;
FIG. 4 presents one design of modulator 140;
FIG. 5 depicts a system configuration employing subcarriers;
FIG. 6 illustrates interrogation pulse control within CO 10;
FIGS. 7-11 present another designs for modulator 140; and
FIGS. 12A-12G illustrate various time slot formats.
DETAILED DESCRIPTION
FIG. 1 presents a block diagram of an optical fiber communications system that comprises a local digital switch or hub, such as central office (CO) 10, remote node (RN) 90, and a number of optical network units, or ONUs, represented by ONU 100, ONU 200, ONU 300 and ONU 400. While it is not necessary, it is convenient to assume that all of the ONUs, or endpoints, are essentially identical in design, although each ONU may have different capabilities. Accordingly, only ONU 100 is shown in detail. CO 10 provides downstream optical signals over fibers to the RNs, such as optical fiber 11 connected to RN 90. Within RN 90, the downstream optical signal is split, i.e., demultiplexed, and the separate developed optical signals are provided to the various ONUs that are connected to the RN via optical fibers, such as ONU 100 which is connected to RN 90 via optical fiber 96. Each ONU can provide service to a number of subscribers, or customers, provided the signals destined to the different subscribers are carried by fiber 96 and can be separated out (e.g. by demultiplexing) at the ONU and delivered to the different subscribers. For the purposes of this description, only one subscriber is discussed, with data out line 121 to the subscriber and data in line 119 from the subscriber.
Turning now to the upstream direction, RN 90 receives an optical signal over an optical fiber from each ONU, e.g., on optical fiber 91 from ONU 100. RN 90 combines (i.e., mixes) the optical signals from each ONU and provides a single upstream optical signal to CO 10 over optical fiber 12. Except as described below, it is assumed CO 10 functions as in the prior art systems in providing services to each of the subscribers associated with each ONU. For example, CO 10 is able to provide a digital equivalent of plain old telephone service (POTS) between a called party, e.g., the subscriber associated with ONU 100, and a calling party, which might access CO 10 over facility 14 or from another ONU. Facility 14 is representative of any number of facilities that couples CO 10 to a telecommunications network (not shown); e.g., an inter-office trunk. Similarly, the data services can range from providing a simple data connection between terminal equipment of the subscriber associated with ONU 100 and a computer system (not shown), or the provisioning of video or multimedia services to a subscriber associated with ONU 100.
As shown in FIG. 1, CO 10 comprises CO processor 15, frequency tunable optical transmitter 20, sequencer 30 and optical receiver 40. Transmitter 20 includes a light source (optical carrier) and a modulator with an electronic signal on line 16 modulating the optical carrier. The optical carrier is developed under control of signal line 31 in a tunable optical signal generator (e.g. tunable laser) or in plurality of lasers that are turned "on" by the signal(s) on line(s) 31. CO processor 15 provides the data that is destined to the ONUs that are coupled to RN 90. That is, the data delivered by line 16 is synchronized to sequencer 30 so that when sequencer 30 causes transmitter 20 to operate at the wavelength assigned to ONU 100, the data on line 16 corresponds to the data that needs to be delivered to ONU 100. Frequency tunable transmitter 20 can be constructed as taught, for example, in "Discretely Tuned N-Frequency Laser for Packet Switching Applications Based on WDM," B. Glance et al., Electron. Lett., vol. 27, pp. 1381-1383, 1991. For the transmitter 20 structure described above (e.g., tunable transmitter), sequencer 30 most naturally operates transmitter 20 in a time division multiplexing mode, as depicted in FIG. 2. There is a plurality of time slots, and each times slot contains optical signals of different wavelength: a first wavelength during a time slot t 1 , a second wavelength during a time slot t 2 , a third wavelength during a time slot t 3 , etc. It may be observed that a strictly WDM system is also possible, where a plurality of lasers are each independently modulated and their outputs are combined. The operation of such a system closely parallels the TDM system described above and is conceptually simpler so, for sake of brevity, only the latter is described in detail. Skilled artisans can, of course, apply the teachings herein to a strictly WDM system.
Although the time slots shown in FIG. 2 are of equal duration, that is not a requirement. The data, or information, impressed onto the carrier during each time slot is destined, typically, to a different ONU and the modulation technique depicted in FIG. 2 is that of intensity modulation (i.e., ASK), with a low modulation index. In this, shallow modulation depth, a logic 1 is represented with a carrier at full intensity, and a logic 0 is represented with the carrier at intensity level 0.8. Of course, other modulation techniques are also possible. The freedom to have time slots of any length offers one degree of control for providing different bandwidths to different ONUs and customers. Another degree of control for adjusting bandwidth is the freedom to employ different data rates at each of the different time slots. This control is illustrated in FIG. 2 by the different widths of the pulses appearing in the amplitudes of the carrier signals.
Although the above describes an RN 90 where signals of only one specific wavelength are directed to ONU 100, that is also not a requirement. A remote node can be employed where a number of wavelengths are directed to a particular ONU, as disclosed, for example, in the aforementioned Darcie 14-10-3 copending application. Of course, the ONU will generally include wavelength division demultiplexing means to separate out the different wavelength signals. One benefit of an arrangement where more than one wavelength is directed to a particular ONU is a greater flexibility that is available in distributing services to customer terminals which are connected to a particular ONU. Another benefit is a distinct maintenance channel, as disclosed in detail in the aforesaid copending application. Aside from being able to make a "go--no go" determination, various other maintenance operations can be carried out without disturbing normal communication with ONU 100, such as measuring power margin (i.e., determining how close the system is to becoming inoperative should the carrier signal power diminish). Measuring power margin can be done, for example, by dividing a time slot into segments and in each segment sending a carrier signal of progressively lower intensity (amplitude). When the sent signal returns to the CO (as described in the aforementioned Darcie 8-1-1 application, also described in detail below), the signal of segments with signal intensity lower than detectable by receiver 40 will, by definition, not be detected, and the last-detected segment would indicate to the CO the power margin that is present in the system. This measurement does not have to be done at a different wavelength, of course. As indicated below, it may be part of the standard maintenance tools that are employed even in systems that send a single wavelength signal to each ONU.
The transmitted optical signal from CO 10 is accepted by RN 90. In FIG. 1, the latter comprises wavelength division multiplexer/router (WDM/R) 95, such as, for example, described in "An N×N Optical Multiplexer Using a Planar Arrangement of Two Star Couplers," C. Dragone, IEEE Phot. Technol. Lett., vol. 3, pp. 812-815, 1991; and in "Integrated Optics N×N Multiplexer on Silicon," C. Dragone, C. A. Edwards, and R. C. Kistler, IEEE Phot. Technol. Lett., vol. 3, pp. 896-899, 1991. WDM/R 95 has linearity and reciprocity properties that allow all the light paths to be reversed. That is, light with wavelength λ applied to fiber 11 is routed to fiber 96, and light with the same wavelength applied to fiber 96 is routed to fiber 11. However, since in some applications it is advantageous to physically separate the upstream and downstream optical signals, WDM/R 95 differs from standard WDMs in that it can be configured to comprise a second set of ports for upstream transmission, as represented by optical fibers 91 through 94 and optical fiber 12. Of course, in the upstream path the signal must be combined, rather than be split up. This can be achieved with a simple power combiner, since the signal timing and wavelengths are dictated by the CO (although there would be splitting losses). Alternatively, the upstream combining can be wavelength selective (without splitting losses). An intrinsic feature of WDM/R 95 is that it accomplishes wavelength selective combining in a manner "slaved" to the concomitant wavelength separation performed on FIGS. 11 and 96-99.
Returning to the description of FIG. 1, ONU 100 accepts the light applied by optical fiber 96 with receiver/modulator 140. The latter comprises passive tap coupler 105, detector 110, and modulator 115. Passive tap coupler 105 splits the incoming light into two signals for application to optical paths 106 and 107. Only a small portion of the incoming light is needed by detector 110 and, therefore, the bulk of the incoming light (e.g., 80%) can be diverted to path 107. Optical path 106 applies its optical signal to optical detector 110, where the optical signal is detected, converted to an electrical signal, and sent on path 111. Path 111 provides this electrical signal to processor 120, which further conditions and processes the signal to provide a subscriber "data out" signal representative of the respective downstream information, via path 121. Optical path 107 applies its signal to optical modulator 115. This signal is the carrier signal that is modulated and sent back to CO 10. The carrier signal is modulated, e.g., ASK, with the data signal that the customer equipment (communicating through processor 120) wishes to sent to CO 10.
It may be noted that processor 120 releases its information to modulator 115 only during periods that processor 120 determines (in response to signals from detector 110) that the carrier signal is present. In applications where the optical carrier of modulator 115 comes directly from coupler 105, it must be taken into account that the carrier may contain an information component, which is the information that was sent by the central office to ONU 100. To differentiate between this information and the data applied by path 143, and keeping in mind that the AM modulation by CO 10 has a low modulation index, one approach for modulating in element 115 is to use a high modulation index, or a "deep modulation depth". This is illustrated in FIG. 3.
Alternatively, the carrier signal applied to modulator 115 can be stripped of its data content (i.e., the data destined to detector 110). This can be done, for example, by including an optical amplifier in path 107 that goes into saturation. Stripping the data off the carrier can also be done with a feedback circuit that takes the output of detector 110 and remodulates the carrier appearing in path 107 to reverse the action of the CO's modulator. This is shown in FIG. 4, with element 130 interposed in path 107. As indicated above, "carrier smoother" 130 may be an amplifier or a modulator that is responsive to a feedback signal from detector 110. Carrier smoother 130 can also be incorporated in modulator 115. That is, the modulation signal on line 143 can be superimposed with data developed by detector 110.
The information-bearing optical signal developed by modulator 115 is applied to RN 90 via path 91. There, the signal is combined with signals from other ONUs and, together, they form the optical signal on path 12 which is sent to CO 10.
In may be noted in passing that the CO inherently knows from which ONU the data is arriving because it is carried on the very same signal that was sent by the central office to a specific ONU. Still it may be advantageous for processor 120 to include information in the data stream. That data can identify processor 120, or the source of the information relayed by processor 120, etc.
It may also be noted that the optical fibers from the different ONUs to RN 90 may differ in optical path length. One possible consequence of different length fibers is that data in a time slot t i which immediately follows time slot t i-1 out of the central office, is not necessarily in the same time relationship with data in time slot t i-1 when it returns to the central office. There may an overlap with time slot t i-1 , or there may be a gap between the two time slots. The overlap can results in collisions at optical receiver 40 between the data of time slot t i and the data of time slot t i-1 . These collisions can be avoided in any number of ways.
One approach for avoiding these collisions is for CO processor 15 to take into account the various time delays before transmission of any downstream information; i.e., transmit time slots with appropriately timed gaps. Another approach is to sequence the data in downstream time slots arranged in increasing order of distance from the RN. Such an approach retains time order at the cost of introducing "dead time" in the downstream signal.
Another approach is to subcarrier modulate the packets in each time frame. This is shown in FIG. 5. The only differences between FIG. 1 and FIG. 5 are voltage controlled oscillator (VCO) 50, mixer 55, and RF filter bank 45 of CO 10. The downstream signal on path 16 is sub-carrier modulated by mixer 55 at one of a few frequencies. In other words, the downstream signal is shifted from a base-band frequency to a radio-frequency (RF) band. At the same time that sequencer 30 signals transmitter 20 to change the transmitter's wavelength, sequencer 30 also changes the frequency of VCO 50. Consequently, transmitter 20 modulates its light output with RF bursts at each particular frequency. The amplitude of each RF burst represents "ones" and "zeroes" in a manner similar to the "baseband" description of FIG. 1. The number of subcarrier frequencies need not be greater than the largest number of overlapping time slots.
Still another approach is to use a plurality of wavelength sensitive optical receivers (in other words, employ a WDM approach at the receiver) but subcarrier filters (e.g., 65, 75, and 85) are typically less expensive than tuned receivers.
From the above it should be understood that while it is essential that an ONU have "some" time slot in a time frame, the details about which time slot is being used is irrelevant to any particular ONU. In other words, since an ONU does not transmit anything back to the CO until it receives an optical signal from the CO, the ONU does not have to have any a priori knowledge about the time-division multiplexing assignments used by a central office. As a result, the time-division multiplexing format, both in terms of amount of time dedicated to an ONU and the sequence of transmissions by the central office to an ONU, can be varied in any fashion desired by the CO without requiring a change to the ONU equipment. This results in no synchronization requirements between CO 10 and an ONU, and allows CO 10 to provide "bandwidth on demand". If ONU 100 signals a need for extra bandwidth and ONU 200 is not busy, the length of time that the central office's laser transmits at the wavelength associated with ONU 100 can be doubled by using the time slot assigned to ONU 200. This kind of reassignment of slots does not require recomputation and reconfiguration of any network synchronization scheme and all of the ONUs are unaware that anything has happened.
The above describes the arrangement shown in FIG. 1 without detailed reference to actually how communication takes place between the central office and a subscriber terminal that is coupled to processor 120. The following describes one mode of operation.
In accordance with the arrangement disclosed herein, CO 10 continually monitors the integrity of the paths to all the ONUs within its realm, such as ONU 100. It does so with a sequencer 32, shown in FIG. 6, which includes a control line 19 emanating from processor 15 in addition to control line 17. Whereas control line 17 directs sequencer 32 to control transmitter 20 to operate at a particular wavelength, as described previously in connection with FIG. 1, control line 19 merely gates the signal of sequencer 32. More specifically, control line 19 causes CO 10 to output a train of bursts, or interrogation pulses, of the carrier signal at the wavelength specified by control line 17. The interrogation pulses may be only a few percent of a time slot's duration (perhaps even less than 1%), and this reduces the power consumption of the CO laser significantly. The interrogation pulses can be at any rate, but one simple approach is to position one interrogation pulse at the beginning of each time slot.
Alternatively, in arrangements where no time slots are employed (such as in a strictly WDM system, the interrogation pulses can go at any rate whatsoever. Modulator 115 optically depicted in FIG. 1 is a transmissive modulator, which can be passive or active. A passive modulator requires no power to pass a carrier signal from path 107 to path 116. An active modulator requires power, but it may also provide gain. Gain is desirable in many applications and, therefore, a simple active modulator may be appropriate. On the other hand, when the modulator is powered "off" (or the ONU itself loses power), it effectively cuts the optical signal path. In many applications it is desirable to continuously test the integrity of the signal path and this requires a path through the modulator (even when the ONU is not communicating upstream). However, the need to provide a source of continuous power is not welcome, and that holds particularly true when the integrity testing can be done with an interrogation pulse, as described above, which is active relatively seldom (e.g., very low duty cycle). Continuously powering the modulator in such an arrangement is truly wasteful of power.
FIG. 7 presents one arrangement where an active modulator is employed which does not require the expenditure of power in order for the CO to test continuity of the path to ONU 100 and back. It comprises a bypass fiber 123 and "single pole, double throw" optical switches 125 and 126. The switches are under electrical control of line 128 (emanating from processor 120) and are arranged to pass the optical signals of path 107 to path 116 either through fiber 123 or through modulator 115. That control may be coupled to the application of power to modulator 115, but as will be disclosed below, there are distinct advantages to have that control be independent. The FIG. 7 modulator is an active, transmissive, modulator. Switches 125 and 126, by the way, can be as simple as electromechanical switches. Of course, they can also be more sophisticated, such as Lithium Niobate electro-optical switches.
FIG. 8 presents another embodiment, where switch 126 is replaced by coupler 129, and FIG. 9 presents still another embodiment (using a reflective modulator) where a single switch, 125, is used. Many other variations are possible, of course, such as a two switch arrangement using a reflective modulator. The FIG. 9 arrangement is useful in systems that employ a "downstream" fiber and a separate "upstream" fiber (e.g., 107 and 116), as well as in systems where a single fiber is used for both "upstream" and "downstream" transmissions (e.g., only fiber 107).
Returning to FIG. 7, the arrangement accepts the optical bursts which arrive at the ONU and are passed onto fiber 107 and forwards those bursts to path 116. According to the teachings above, the CO detects the return of those optical bursts, and from that detection determines that the path to and from ONU 100 is operative. Taking advantage of the independent control over power line 127 and control line 128, processor 120 can employ the following operational schema.
When the customer terminal that is coupled to processor 120 is not in use, control line 128 includes fiber 123 in the signal path and power line 127 maintains modulator 115 in a "power off" state.
When the customer terminal detects incoming information (with detector 110) and concludes that it wishes to send information to the CO (e.g., the central office is applying a "ringing signal" and the customer terminal chooses to go "off hook"), then modulator 115 is included in the signal path (excluding fiber 123 from the signal path) and is powered "on".
When, in the absence of a signal from the CO (other than the repetitive optical bursts), the customer terminal wishes to send information to the CO (e.g. to dial out and make a call), then modulator 115 is included in the signal path (excluding fiber 123 from the signal path) but modulator 115 is kept in its "power off" state, or the modulator power is turned "on" but the modulation signal on line 143 is set to its minimum transmissiveness level (i.e., the modulation is effectively turned "off").
With such a schema in place, the CO can effectively employ the interrogation pulse notion disclosed above. When such pulses are sent to the ONU, CO 10 expects a return of the interrogation pulses, to confirm that the system is operational. When the interrogation pulses do not return, the CO knows that either the system failed or that the customer equipment placed the modulator of FIG. 7 in the signal path but withheld power to the modulator. According to the above protocol, the latter indicates that the customer's terminal has gone "off hook". The proper response by the CO to this condition is to provide a "dial tone" signal to the customer terminal. The dial tone can be generated at CO processor 15 and a digital signal that corresponds to a dial tone can be applied to line 16. Alternatively, CO processor 15 can send a code to processor 120, and processor 120 can generate the dial tone locally. Of course, processor 120 must turn modulator 115 power "on" for it to send the dialing signals to CO 10. Processor 15 responds to the dialing signals in a conventional manner. The called party specified by the dialing signals is coupled to processor 15 (perhaps via facility 14) and communication proceeds. What that means is that, instead of the short interrogating bursts, the CO provides an appropriate duration optical signal carrier during the time slots that communicate with the calling party at ONU 100. In the course of such "normal" communication, when signals are sent to the called party (the party not at ONU 100) the carrier from the CO to the ONU is modulated with signals from processor 15, and when the calling party (the customer at ONU 100) is transmitting a signal the optical carrier signal that flows back to the CO is modulated by 115.
The monitoring of the "health" of the communication path can continue even in the absence of interrogation pulses because there is sufficient energy in the returned signal to serve the needs of the circuit that does the monitoring. Stated in other words, the fact that communication is taking place is sufficient indication that the system is operational. The evaluations that are necessary for performing the monitoring function are carried out, of course, in receiver 40 and CO processor 15. Receiver 40 detects the optical signals, demultiplexes the subcarriers, demodulates the signals, and converts the resulting baseband signals to electrical form. Processor 15 takes the electrical digital signals developed by receiver 40 and analyzes them in a conventional manner (e.g. using filters, accumulators and threshold detectors) to determine whether a returned signal is present at the time it is expected to appear at fiber 12.
In the event that the CO provides a "dial tone" (or a code indicative thereof) but no dialing signals are detected in response, the CO concludes that there is a failure in the tested path and, then, OTDR or a similar process can be initiated. OTDR processes are well known, and are referenced in the above-identified Darcie 14-10-4 application.
It may be noted that the monitoring of the communication path even during an active connection between a customer terminal coupled to ONU 100 and some other customer terminal has a benefit other than just the knowledge gained by the maintenance system the system continues to be operational. For example, this monitoring can be used to detect "end of conversation" condition, or to detect a "hook flash" condition. The manner of such detection is effectively as before. On the ONU side, when the customer terminal executes a "hook flash" or terminates the communication, processor 120 turns power off to modulator 115 (for a short predetermined time, in the case of a "hook flash", or permarrently, for an "end of conversation" condition) but keeps modulator 115 in the path of fibers 107-116. When CO processor determines that the continuous carrier signal has not returned for an interval greater than a preselected threshold (because modulator 115 was turned "off"), it first makes the tentative conclusion that it sees a "hook flash". When the carrier signal resumes its return to the CO (when it indeed is a "hook flash" condition), the CO confirms the conclusion that it experienced a "hook flash", and responds accordingly in a conventional manner. When the carrier signal continues to not return, the conclusion is made that either the customer terminal went "on hook", or the communication path failed. Assuming the former, the CO sends a message to processor 120 in ONU 100, directing it to confirm the "on hook" condition. Processor 120 does so by switching modulator 115 out of the signal path and inserting fiber 123 in the path (via control of switches 125 and 126). Placing fiber 123 in the path allows the optical carrier to return to the CO, which serves as the sought confirmation, and in response thereto, the CO returns to the pulsed monitoring mode; i.e., returns to sending the interrogation pulses.
While the above-described process of call establishment, communication, and call termination are couched in terms of a desire on the part of the customer terminal and readers might envision a human user activating the customer terminal, e.g. a telephone, it should be understood that the processes described above can be arranged to occur upon the occurrence of any other event, such as a fire or burglary at the home of the customer, etc. Still other ways are available for achieving these sought results, and it should be understood that the above is merely illustrative of the principles disclosed herein.
FIG. 10 presents still another embodiment of receiver modulator 140, where a transmissive modulator 115 is flanked by coupler 131 and 129, and a switch/modulator 132 is interposed in fiber 123. Element 132 can be a fiber, a simple "single pole single throw" mechanical switch, another modulator, or a modulator combined with a switch (e.g., serially). There is a particular advantage to using a passive modulator for element 132 in that it provides a second, distinct, channel of communication to the CO. That is, because it is passive, no expenditure of power occurs on its behalf at ONU 100. Moreover, the signal returned to the CO is markedly different in magnitude from the signal returned from modulator 115, and it could be even more different if the modulation technique used is different from that of modulator 115. For example, the signal modulating the carrier at element 132 can be an analog signal, while the signal modulating the carrier at element 115 can be a digital signal, or vice-versa. Also, instead of coupler 131 and 129, either one or both can be switches, in which case element 132 may be a mere modulator.
To a skilled artisan the possible variations are almost endless.
As for use of this enhanced capability, passive modulator 132 can be used to monitor a home for emergency conditions, can be used to read-out information from the home, such as reading power meters, etc. Even mechanical modulation of the light is possible.
In operation, when element 132 does not wish to communicate and the customer terminal is "on hook", modulator 132 is made to pass carrier signal (i.e. is made fully transmissive) and modulator 115 is turned "off". The CO bursts pass through element 132, and the operation is as described before. When an emergency condition occurs and element 132 wishes to communicate information, it turns least transmissive and the CO (in response thereto, as described before) sends a dial tone. Under control of processor 120, element 132 sends a particular data sequence and the CO responds accordingly. From the magnitude of the signals the CO knows that it is modulator 132 that is communicating. The CO can, therefore, provide appropriate compensation (e.g. gain or filtering) and simply make the appropriate connection. In the alternative, it can accept the data sequence as an instruction to the CO to take some predetermined action.
In the forward direction, when the CO wishes to access information from the customer via element 132 rather than make a full fledged connection to the customer's terminal, it sends an alert signal to processor 120 (via detector 110) that is different from the normal alert signal. Processor 120 responds appropriately by sending the sought information over the element 132 channel, and the desired result is achieved. It may be noted that the same can be accomplished by using modulator 115.
In applications where element 132 is a switch, the operation is identical to that of FIG. 7. In applications where element 132 does not exist, which is the case when it is said to consist of merely a fiber, the operation must rely on a somewhat finer control of modulator 115. That is, the above-described operation depends on having three states: a state where the bursts are returned (fiber 123 is in the path), a state where bursts are not returned (fiber 123 is not in the path and modulator 115 is "off), and a state where a carrier signal is modulated at enhanced amplitude (modulator 115 is "on"). In an arrangement where fiber 123 connects couplers 129 and 131 directly, the three states would be a state where bursts are returned, a state where the bursts are returned amplified somewhat (modulator 115 is turned on, and control 128 is set to a preselected amplification level), and a state where the carrier is modulated. Of course, on the CO side there would be a fourth state, where no bursts are returned at all. CO processor 15 can easily accommodate the enhanced capabilities that the fourth state presents. It should me noted that the arrangement where there is only a fiber between couplers 129 and 131 is likely to create interferometric noise, fading, etc.
Yet another arrangement can simply follow the FIG. 1 structure where only control over the output of modulator 115 is employed, provided that modulator 115 is passive. For example, when the customer terminal is "on hook", modulator 115 can be set to a state where is passes signals unaltered (i.e., maximum transmissive state). That allows the interrogation pulses to return to the CO. When the customer's terminal goes "off hook", the modulator is set at its least transmissive state, and the CO is faced with the question of whether the terminal is "off hook" or the signal path failed. That question is resolved as discussed above. When communication actually takes place, the modulator modulates the carrier as described above. Alternatively, the "off hook" condition can be specified by some other state of the modulator, such as placing the modulator in a medium transmissive state, alternating the modulator between minimum and maximum transmissive states at some preselected rate (slower than the repetition rate of the interrogation pulses), etc. The latter approach can also be used with active modulators.
FIG. 11 presents an embodiment where the splitting of the signal that occurs in element 105 of FIG. 1 and the modulation that occurs in element 115 are combined. Specifically, element 135 is a splitter with a built-in optical amplifier. Based on the value of the signal on line 128, a portion of the optical signal (amplified) that is applied by fiber 101 is directed to path 116, and the remainder is directed to path 106. Alternatively, element 135 can comprise a coupler of the type described above followed by an amplifier in the output leg that goes to fiber 116.
When the communication between the customer terminal and some other terminal is such that simultaneous transmission in both directions is not essential then, of course, there is no need for smoother 134. When data is being sent to detector 110, control signal 128 is at a dc level that corresponds to the sending of no energy to path 116 and the sending of all optical energy to detector 110. When data is being sent to the CO, control signal 128 modulates amount of energy that is sent to path 116, and the CO receives the sent data. Of course, the complement of the signal sent to the CO also arrives at detector 110 (less the amplification that may be present in the path to the CO), but detector 110 can be disabled or made to ignore its reception.
When the communication between the customer terminal and some other terminal needs to be fully duplex (i.e., permitting of communication in both directions simultaneously), a smoother 134 is interposed between element 135 and detector 110 which is under control of data line 128. Smoother 134, which may be passive or active, removes the effects of modulator 135, so that detector 110 sees only the data sent to it by CO 10.
Having mentioned the notions of "full duplex" communication, it should be pointed out that the above uses the term in the sense of having a carrier which, effectively, carries communication in both directions simultaneously. It does not refer to the notion of communication always flowing in both directions (such as in a conventional, analog, "plain old" telephone service). But that notion has to be taken in light of the general structure of the FIG. 1 system, where communication between CO 10 and ONU 100 is contemplated to occur only whenever the CO outputs a carrier of the right wavelength, and the latter occurs as dictated by sequencer 32 (or 30). Data signals typically have no problem with being sent in bursts, during the appropriate time slot. Speech signals, likewise, have no problem if some appropriate delay is acceptable. Given that fact, the distinction between half duplex and full duplex is effectively obliterated when the time slot during which sequencer 32 causes to CO 10 to communicate with ONU 100 is divided into a "send" segment and a "receive" segment. If the send and receive segments are long enough and the bandwidth during those segments is high enough to provide the necessary overall bandwidth, then on a macroscopic level a full duplex operation is attained even though on a microscopic level the operation is half duplex.
With that in mind, FIG. 12 depicts various possible signal conditions during a time slot when communication occurs with a particular ONU, such as ONU 100. FIG. 12A depicts an interrogation pulse. FIG. 12B depicts an interrogation pulse that is wide enough to include a reducing amplitude segment (or a sequence or trailing pulses with a predetermined set of generally declining amplitudes that is used to measure power margins, as described above. FIG. 12C shows a time slot that includes segments C and A. Segment C is a control segment, and segment A is a data segment. The communication segment provides a communication channel that can be employed throughout a communication session. The control segment provides a control channel from the CO to the ONU, which can be used throughout a communication session between a customer terminal coupled to an ONU and some other customer terminal, or even in the absence of such a communication session. FIG. 12D shows a control segment that includes a power margin test. FIG. 12E shows a control segment C and communication segments A and B. During segment A, CO 10 sends information to the ONU, and during segment B the ONU sends information to the CO. FIG. 12F depicts segments C, A, and B, and further shows segment C being divided into sub-segments C1 and C2. Sub-segment C1 is a control segment where CO 10 sends control information to the ONU, and sub-segment C2 is a control segment where the ONU sends control signals to the CO. FIG. 12F also depicts a condition where sub-segment C1 and segment A are much smaller than their siblings, sub-segment C2 and segment B, respectively. This condition may be employed when the customer's terminal is one where there is a natural disparity between the incoming and outgoing data rates, or a condition where the actual modulated data rates are different. The latter arrangement may be used when, for example, it is less expensive to employ an ONU which can receive high data rates but can only transmit lower data rates than it is to employ an ONU which can receive and transmit at the same data rates. FIG. 12G depicts a time slot with control segments C, A and B, and further shows that segment B is modulated at some preselected, relatively high frequency, subcarrier. This subcarrier is effectively a clock signal. This clock signal can be used by the CO, when it returns with the data from the ONU (e.g. to assist in the detection of the data), can be used by the ONU, or both.
It may be noted that a system arrangement such as disclosed in connection with FIG. 1 is not limited to any one specific time slot format, such as the ones shown in FIG. 12. Rather, the formats can be dynamically modified as the need arises. For example, the FIG. 12C format may be to send a "ringing packet" to the ONU, while FIG. 12G format is used during a communication session.
One of the major advantages of the system disclosed above is the fact that the ONUs are basically subservient to the CO; i.e., effectively all control is exercised by the CO. One variable that has not been addressed above is variations in the RN due to design tolerances and, more significantly, variations due to temperature changes. RN routers are typically placed outside the central office buildings and, having managed to create an RN that is totally passive, it makes sense to allow the placement of the RNs in the "outside plant". However, even though a passive RN (e.g. comprising glass gratings) is a rugged device, it is typically temperature sensitive in its wavelength selectivity. One approach for solving the potential mismatch between the wavelengths that are deployed by the CO and the wavelengths to which the RN is sensitive is to monitor the RNs' responses at the CO and to modify the wavelengths of the lasers accordingly. This additional control is shown by control line 21 in FIG. 1 which CO processor 15 applies to element 20. Internally within CO processor 15, a software feedback loop is executed where the wavelength at which a laser is operating while communicating with a particular ONU is periodically modified. The output of receiver 40 is compared to the output of receiver 40 prior to the wavelength's modification. When the output of receiver 40 increases, the conclusion is made that the modification was beneficial, and the succeeding modification is made in the same direction (i.e., reducing or increasing the wavelength, whichever was done before). When the output of receiver 40 reduces, the conclusion is made that the modification was detrimental, and the next modification is made in the opposite direction. By this process, the cooperation between receiver 40, CO processor 15 and element 20 under control of signal 21 causes the output of element 20 to properly follow the needs of the considered RN and, correspondingly, of all other RNs in the system. | A communication system where a central module repetitively sends interrogation optical pulses to endpoint modules in order to determine operational state of the endpoint modules and of the two-way communication path to the central module. Those pulses also determine whether the endpoint module wishes to initiate communication with the central office. In the endpoint module, a modulator whose function is to send data from the customer's terminal is arranged to operate in two distinct modes. When it is "powered off", which is when the customer terminal is inactive, it allows central office signals to loop-back to the central office. In this state, the optical pulses sent by the central office serve the function of optical continuity checking. When an endpoint module wishes to establish a connection, i.e., the customer terminal wishes to "make a call", the modulator is arranged to interpose itself in the loop-back path and inform the central module of its desire, such as by temporarily turning off the path to the central. When the optical interrogation pulses fail to return to the central office, the central module knows that either the endpoint module is wishing to make a call, or a break exists in the communications path. The central module assumes that the endpoint module desires to make a call and responds by sending an acknowledgment. Thereafter, the endpoint module can proceed with communication. | 7 |
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is a Continuation-in-Part of application Ser. No. 10/230,446, filed Aug. 30, 2002 (published on Mar. 4, 2004 as Application 20040040184) by the present inventor, Customer 3571. Disclosure Document 511438 covering this invention was mailed on May 6, 2002 and acknowledged by the PTO on May 13, 2002.
BACKGROUND OF THE INVENTION
[0002] a. Field of the Invention
[0003] The invention relates to devices for removing snow from driveways; from streets, roads, highways, etc. (hereinafter for simplicity called “roadways”); from all or parts of parking lots; and from sidewalks and other walkways.
[0004] b. Description of the Prior Art
[0005] Most plows for the removal of snow are mounted on the front of a vehicle. However, snowplows made for attachment to the front of vehicles are very heavy and require much bracket hardware and other complex hardware for controlling and stabilizing purposes. Their weight and rigidity often cause damage to roadway surfaces, curbs, and imbedded reflectors in fog-prone areas. Such snowplows are also very expensive, bulky, and heavy—too much so for the individual householder, the small-business person, the entrepreneur offering light-duty snow removal service, or a teenager seeking after-school or weekend jobs. Such snowplows are difficult to assemble, difficult to attach to vehicles, and, when not needed out of season, difficult to detach and to store. Further, such snowplows are not suited for attaching to ordinary automobiles or other relatively lightweight vehicles, requiring instead some kind of heavy-duty truck.
[0006] Modern vehicles are able to travel without difficulty over new-fallen snow, otherwise still-soft snow, or slush several inches deep, even without such enhancing equipment as all-weather tires, four-wheel drive, limited-slip differential, etc. Therefore, if a vehicle can drive over a snow-laden path, a towed snowplow is practicable.
[0007] A number of snowplows have been designed for attaching to the rear of vehicles or other means of propulsion. However, they suffer many limitations and disadvantages.
[0008] Two of these devices, for example, under U.S. Pat. Nos. 3,800,447 to Harvey and 4,907,357 to Lilienthal are designed not for general removal of snow from a path, but merely to remove snow from a close to a wall or garage door where the vehicle's front-mounted plow cannot each.
[0009] In another example, a grading device under U.S. Pat. No. 6,070,343, to Sheldon, intended for grading or snow removal, is to be attached to a towing hitch. Most vehicles are not equipped with or suited for towing hitches. Further, among other disadvantages, the device has no provision for stability in relation to the rear of the vehicle. Differential resistance of snow or some small object encountered on the left side of the device, looking forward, would cause the chain on the right side to collapse and destroy the plow's ability to properly deposit the snow.
[0010] Still other devices, such as those under U.S. Pat. Nos. 4,403,432 and 5,595,007 to Biance, and U.S. Pat. Nos. 5,930,922 and 6,151,809 to Altheide require much hardware to control the lifting and aiming of their devices. Such devices are very heavy, probably requiring handling by more than one person, they are time consuming to assemble and disassemble and to attach to and detach from a vehicle. They incur great expense, and they require a large space for storage.
[0011] Some snow clearing devices designed to be drawn purport to be snowplows, but are really devices that could be better defined as “scoops” or “gatherers.” For example, see U.S. Pat. No. 79,913 to Lewis, a vee-shaped device intended to clear snow from skating ponds and ice-lakes. Snow is repeatedly gathered inside the vee of the device and hauled to the side of the pond or lake and dumped. Another example occurs in U.S. Pat. No. 235,201 to Bond, whose snow scraping device also is intended to gather snow inside the vee of the device and remove it “from the surface of ice ponds and rivers where ice is to be cut and gathered.”
[0012] Features that permit a snowplow to be lifted, manipulated, and carried by one person—light weight, compactness, and handhold devices—are of great importance in a light-duty vehicle-drawn snowplow. Several snowplow devices are purported to have parts that are of lightweight material, but their entire assemblage is not light in weight; for example, see U.S. Pat. No. 4,680,880 to Boneta (which happens to be for a front-loaded device), whose device is composed of many parts, most of them of heavy steel. In some cases, even if the device has some lightweight elements, the entire assemblage is both heavy and composed of multiple units impossible to lift and handle together; for example, see U.S. Pat. No. 1,393,724 to Lackie).
[0013] The blades of some snowplows have been fitted with replaceable wear strips, designed to prolong the life of the blades used for heavy-duty service. Examples are the snowplow under U.S. Pat. No. 1,811,436 to Luyster, which has steel wear strips fitted to wooden blades, and the moldboard for a snowplow under U.S. Pat. No. 3,477,149 to Wagner, which has very hard polyurethane rubber, on the order of 85 Durometer (that is, somewhere between the hardness of shoe heels and bowling balls). While these very hard, inflexible wear strips may serve their purpose to prolong blade life, they fail to address the problem of providing a cleaner removal of snow from surfaces that are uneven.
[0014] The methods used to vary the widths of various vee-shaped snowplows that have been patented are more cumbersome and time-consuming than necessary. For example, U.S. Pat. No. 509,811 to Jones discloses a hand-pushed snowplow whose width is varied by attaching a crossbar at varying points on both blades of the plow, a procedure that can be improved upon. In another example, under U.S. Pat. No. 1,811,436 to Luyster, varying the width of the snowplow is accomplished by using an adjustable crossbar consisting of a pipe within a pipe set at different lengths by use of a pin through holes in the pipes. It is not made clear how the pin is made secure, but it probably calls for some manipulation. This method is also one that can be improved upon.
[0015] A vee-shaped snowplow that is intended to be disassembled for storage or transportation needs a simple, uncomplicated, and inexpensive means of attaching and detaching its blades to and from each other at the vee point. An example of a vee-point that does not meet these criteria is shown in U.S. Pat. No. 509,811 to Jones, which calls for the manufacture and assembling of a completely separate vee-point unit, consisting of several parts. Another example of a device that fails to meet these criteria is shown in U.S. Pat. No. 1,811,436 to Luyster, which also calls for the manufacture and assembling of a complex multiplicity of parts. Still another example of a device that fails to meet these criteria is shown in U.S. Pat. No. 1,393,724 to Lackie, whose hinge is undoubtedly of the conventional kind having two plates with several knuckles, which requires two hands to exactly line up and hold the knuckles in place, and requires a third hand to insert a pin through the knuckles.
[0016] What is needed and not provided in the prior art is an effective snowplow with a minimum number of parts; that does not require attaching to a trailer hitch or other special hardware on the towing vehicle; that is simple and inexpensive to manufacture and sell; that is compact for shipping, transporting, and storing; that is lightweight and compact enough to be handled by one person, adult or teenager; that can be easily and quickly assembled and disassembled by one person; that can be easily and quickly attached to and detached from a vehicle; that does not require cumbersome and unsightly hardware on the towing vehicle; that is simple and efficient to operate; that is stable in use; that is as easily adjustable in width as possible; that can easily be adjusted to deposit snow on either or both sides of the path being plowed; that has provision for cleaning uneven surfaces; that requires very little propulsive power; that can overcome unusual or unexpected minor obstructions in the path being plowed; that is durable; and that will rarely, if ever, need repair.
[0017] The present invention addresses all of the limitations and problems found in the prior art, and it is designed to fulfill all of the criteria listed in the preceding paragraph.
SUMMARY OF THE INVENTION
[0018] The present invention is a device for the removal of new-fallen snow, otherwise still-soft snow, or slush from driveways, roadways, all or parts of parking lots, and from sidewalks and other walkways. (Since the object of plowing is to remove snow as soon as possible, virtually all snow to be removed is new-fallen or, at least, still soft.) This invention has a minimum number of parts, is effective, simple, inexpensive, lightweight, easily and quickly assembled and disassembled, easily and quickly attached to and detached from any kind of vehicle (with no cumbersome or unsightly hardware on the vehicle), compact, quickly and easily adjustable in width, quickly and easily adjustable in the direction of snow deposit (right or left side), operable with very little propulsive power, and not defeated by minor obstructions in the path being plowed.
[0019] Shortly after or during a snowstorm, people begin to remove snow with a shovel or a powered snow thrower, or engage vehicles with conventional plows to remove snow from driveways, roadways, parking lots, and walkways.
[0020] Shoveling snow is burdensome, time-consuming, and often dangerous to health and even life.
[0021] As far as snow throwers are concerned, Consumer Reports magazine (October 1997, page 28) pointed out that “Though faster and less physically taxing than shoveling snow, using a snow thrower isn't effortless or without its annoyances. It demands some awkward maneuvering of a heavy machine. And a snow thrower is costly. Expect to pay $300 to well over $1000, along with the ongoing costs of fuel, oil, and servicing. You'll also need a sizable space in which to store it.” Further, snow throwers are not without their dangers; hospitals have reported quite a few cases each winter of fingers lost to snow throwers.
[0022] Vehicles engaged to remove snow are heavyweight vehicles with heavy plows attached, they are expensive to hire, they often cause damage to surfaces being plowed, they require much fuel for their operation, and consequently they cause much pollution of the air.
[0023] An object of the present invention is to contribute to conservation of the environment by providing a plow that (1) uses a minimum of material, (2) is lightweight, (3) requires very little propulsive power, (4) can be pulled by any motorized vehicle, (5) uses very little fuel for vehicle operation, and (6) causes a minimum of air pollution.
[0024] Another object of the present invention is to provide an effective, yet inexpensive way for users to remove large quantities of snow quickly, with very little physical effort, and with virtually no expense. Even if it were desirable to hire the removal of snow, engaging someone using a plow of the present design (possibly a teenager with a license to drive) would undoubtedly cost less than engaging someone using a conventional heavy-duty plow.
[0025] Another object of the present invention is saving the health and lives of many people each winter. Shoveling snow causes back strain in some people and heart strain in others. Still others suffer injuries from falling. Each year hospitals treat people who have had fingers cut off by snow throwers, as mentioned above. In spite of warnings, each winter many people attempt to clear snow from driveways and they die from the attempt, reportedly not only from the physical effort to push and lift snow, but also from breathing problems in the harsh weather conditions.
[0026] Another object of the present invention is to reduce the amount of time the user needs for clearing snow, and to reduce the user's time of exposure to the elements.
[0027] Another object of the present invention is to provide a means of removal of snow without resort to the use of salt, calcium chloride, or other substances that can be detrimental to the environment and harmful to automobile bodies.
[0028] Still another object of the invention is to provide a safe, cleared path for walking between the house and the front of the property for, say, reaching a curbside mailbox, moving trash for curbside pickup, or any pedestrian or bicycling purpose.
[0029] The present invention, after a minute or less to attach the lightweight plow to a vehicle, can clear great quantities of snow in a matter of seconds, without physical effort or breathing problems in cold and often windy conditions. The residence-size plow is light enough, under thirty pounds (less than fifteen pounds for each blade unit), that it can be easily handled by one adult or teenager. The larger sized plow of this invention, designed to clear even wider paths, is still light enough that it can handled by one adult of average strength. A small version of the plow is designed to clear long sidewalks and other walks, and it can be pulled easily by a farm tractor (or even by a lawn tractor or ride mower for snowfall up to about four inches, and higher levels of snow if the mower deck is removed for clearance).
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0030] [0030]FIG. 1 is a top view of the snowplow set to deposit snow on both sides of the path being plowed.
[0031] [0031]FIG. 2 is a side view of the snowplow.
[0032] [0032]FIG. 3 illustrates a lift-off (and thus “drop-in”) quick-connect hinge, which is just one of several possible means of connecting the two blade units to form the front end of the plow.
[0033] [0033]FIG. 4 shows a top view of the snowplow set to deposit snow primarily on the right side (facing forward) of the path being plowed. (A corresponding arrangement, not here illustrated, deposits snow on the left side.)
DETAILED DESCRIPTION OF THE INVENTION
[0034] The present invention is a snowplow whose blades are made of lightweight material such as, but not limited to 1 , plastic (PVC, vinyl, acrylic, etc.), fiberglass, composite material (such as carbon fiber reinforced plastic, which is one of thousands of available kinds of composites), aluminum, or other lightweight metal. Under ordinary use, these blades will leave little snow after plowing, and will be very durable. However, for even cleaner snow removal, optional strips of tough, but flexible, material (not illustrated in the drawings) may be attached to the blades' contact edge, which meets the surface being plowed. In very-frequent-use situations, optional metal or other hard, inflexible strips may be attached to the lower, or contact, edge of the plow's blades to extend blade life.
[0035] The plow consists of two blade units that can be connected to each other and attached to a towing vehicle in less than one minute. It can be detached and disassembled in like time.
[0036] [0036]FIG. 1 is a top view of the plow showing two rigid members, hereinafter called “struts” 1 , which are attached to the concave faces 2 of the plow blades 3 by a means of attachment 4 on the strut and a means of connection 5 a on the blade. (The struts normally remain attached to the plow blades, but are removable for the purpose of repositioning the plow to redirect the deposit of snow, as will be explained below under FIG. 4.) The other ends, or loose ends, of the struts 1 are attached by means of attachment 6 on the struts fastened to means, or points, of connection 7 , such as small drilled holes in or small eye-bolts on the towing vehicle's bumper or bumper cover 8 (hereinafter for simplicity called “bumper”), or other convenient locations on the vehicle.
[0037] In this embodiment, these struts 1 are of equal length, set at equivalent points on the two blades 3 , in order to deposit snow equally on both sides of the path being plowed. The struts are rigid in order to stabilize the plow, not allowing it to sway to one side or the other when subjected to differential resistance on the two faces 2 of the plow blades 3 —unlike earlier versions of plows attached to a towing vehicle at one point (such as a trailer hitch) or connected to the towing vehicle by a flexible and/or collapsible means (such as a chain or rope).
[0038] The front faces 2 of the plow blades 3 are concave (and the rear faces 9 are, of course, convex). The blades are tilted backward so that the tops of the blades are farther from the towing vehicle than the bottoms of the blades; this causes the snow to press down on its way to disposal, thereby helping to keep the plow hugging the surface of the path being plowed, and avoids the necessity to use heavy materials.
[0039] A connection means, such as a lift-off (and thus “drop-in”) quick-connect hinge 10 , which is a plate on one blade with a hollow tube attached to the outer side facing the edge of the plate, and a plate on the other blade with a pin attached to the outer side of that plate, whereby the pin fits into the hollow tube of the first plate, affording a quick and easy method of assembling and disassembling the snowplow with only two hands. Thus this hinge connects the front ends of the two blades, which are flattened and trimmed to receive the hinges. A retaining pin 16 is passed through holes in the snowplow blades 3 , just above the hinge 10 , which prevents one plate of the hinge from rising above or lifting off the other plate of the hinge as a result of uneven vertical pressures during operation. Convenient handhold means 11 are provided in or on the blades to ease lifting, carrying, and manipulating the blades and indeed the entire snowplow.
[0040] A transverse element 12 “inside” the plow is attached to one blade (in this illustration the right blade) by a means of attachment 13 hooked to a means, or point, of connection on the blade 14 e. It is attached for plowing to the other blade by another means of attachment 15 on the loose end of the transverse element, hooked to a means, or point, of connection 14 a on the other blade. The transverse element 12 serves two functions: it helps to stabilize the plow, and it is a bar used to set the plow blades to the width of the path desired. In one embodiment the transverse element is a fixed-length crossbar 12 hooked by a means of attachment 13 to just one means, or point, of connection 14 e on one blade (again, the right blade) and to the other blade at one of several means, or points, of connection 14 a, 14 b, 14 c, or 14 d affixed along the length of the left blade; the closer to the front point of the plow, the wider the plowed path would be. By design, this method requires only one length of transverse element and only one reattachment to change the width of the plow, unlike methods used in the past with a plurality of crossbars of various lengths, and requiring more than one reattachment. In another embodiment the transverse element is a telescoping bar composed of two submembers, one sliding within the other, which has aligning holes at suitable intervals to receive a spring-activated stub, which automatically locks the two submembers into any one of several fixed lengths.
[0041] [0041]FIG. 2 is a side view of the plow showing one of the two struts, 1 , which is attached to the face 2 of the plow's right-side blade 3 by a means of attachment 4 on the strut and a means of connection 5 a on the blade. The other end, or loose end, of the strut 1 is attached by a means of attachment 6 on the strut fastened to a means, or point, of connection 7 , such as a small drilled hole or a small eye-bolt at the underside edge of the vehicle's bumper 8 , or other convenient location on the vehicle.
[0042] The forward ends of the blades 3 (constituting the front point of the plow) are beveled at the bottom 16 , the purpose of which, along with other elements, is to help the plow rise over any small obstruction that may be in its path.
[0043] [0043]FIG. 3 illustrates the a lift-off (and thus “drop-in”) quick-connect hinge 10 , which is described above in paragraph 0037, and which is just one of several possible means of connecting the two blade units 3 to form the front end of the plow.
[0044] [0044]FIG. 4 is a top view of the plow with the plow set at a narrow width and the left strut, 1 attached to a means of connection 5 b near the front of the left blade 3 , in order to orient the plow for deposit of the bulk of the snow on the right side of the path being plowed. (Repositioning the right strut, instead of the left strut, would cause the bulk of the snow to be deposited on the left side of the path, of course.) In another embodiment, instead of repositioning one of the fixed struts, the same effect is accomplished by the use of optional, but more expensive, telescoping struts to reorient the plow by extending the length of one of the struts. (The telescoping strut used in this invention is a device composed of two submembers, one sliding within the other, which has aligning holes at suitable intervals to receive a spring-activated stub, which automatically locks the two submembers into any one of several fixed lengths.)
[0045] In operation, the user assembles the plow in a matter of seconds, as follows: The user connects the leading ends of the right and left blades to each other to form a vee at the vertex by attaching one part of the quick-connect hinge installed on one blade 3 to its corresponding part on the other blade 3 , and a retaining pin is passed through the blades, as described above in paragraph 0037. The user then attaches the loose end of the tansverse element 12 to one of several means, or points, of connection 14 a, 14 b, 14 c, or 14 d on the left blade, as described above in paragraph 0038. Then, in a matter of a few more seconds, the user attaches the loose ends of the struts 1 to the means, or points, of connection on the towing vehicle's bumper 8 or other convenient location, as described above under FIG. 1, paragraph 0034. When not in use, these bumper means of connection do not leave unsightly hardware equipment on the vehicle to impair its attractiveness, as in the prior art in many instances.
[0046] After assembling the two units of the plow and connecting it to the towing vehicle, the vehicle slowly advances over the path to be cleared. A one-hundred-foot-long driveway, for example, is cleared of virtually all snow in about fifteen seconds; a fifty-foot-long driveway in half that time. It's that quick and easy. Sometimes, depending on the kind of snowfall, a small amount of surface snow (no more than the amount left by conventional plowing equipment), and the narrow tracks of the tires are all that may remain in the path plowed. Any such residue is usually eliminated soon by melting, evaporation, or sublimation between storms, but in any event, no difficulty remains for the passage of vehicles over the plowed path.
[0047] In the case of multiple plowings, such as when snow drifts, or when a blizzard of, say, fifteen or twenty inches of snow is predicted, or in an area of frequent snow storms, the user may wish to plow a wide path the first time, say nine feet wide in a driveway. For a second pass, after another accumulation of snow, an eight-foot path could be plowed within the first nine-foot path. A third or fourth pass, if necessary, can be made by simply narrowing the width of the plow. Since automobiles and station wagons in general need only a five-foot track width (pick-up trucks and some sport utility vehicles slightly more), this example gives ample opportunity to keep a drive path clear of snow for passing through. In most areas, normal sunshine and warm periods of the day will serve to eliminate or lessen the accumulation of snow between storms.
[0048] In some circumstances it may be more desirable to deposit the bulk of the snow to one side of the path. This can be accomplished by orienting the plow as described above under FIG. 4, paragraph 0042. The path plowed will be narrower in this case, but still wide enough. A second pass for greater width can be made, if desired.
[0049] Because of the plow's light weight, the angle at which the blades move forward, the front point 16 (in FIG. 2) of the plow beveled in relation to the surface, and the small amount of “play” in the connections, the plow will not cause damage to surfaces plowed or to curbing, and it will easily rise over any small bumps or minor obstructions in its path, such as the reflectors imbedded in many roads in fog-prone areas—without damage to the objects or the plow. (Such reflectors, in this example, are often damaged or dislodged by conventional plows, requiring labor to install displaced, new, or repaired reflectors.)
[0050] To aid in the dispersal of snow, the blades of the plow may be coated with a lubricant such as silicone spray, but this is not really necessary.
[0051] Upon completion of plowing, the user disconnects the plow from the vehicle and separates one unit of the plow from the other (in less than one minute), nests one unit of the plow into the other, and stores it horizontally or vertically in a relatively small space. | A lightweight, adjustable snowplow, able to be lifted, carried, and manipulated by one person (adult or teenager) of normal strength, designed to remove new-fallen or otherwise soft snow or slush. It has a minimum number of parts. A plurality of struts attaches the plow to any kind of towing vehicle, providing horizontal stability. No brackets, hitches, or lifting devices are needed on the towing vehicle. | 4 |
CROSS-REFERENCE TO RELATED APPLICATIONS
Not Applicable.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
Not Applicable.
TECHNICAL FIELD
The present invention relates to gas turbine engines. More particularly, embodiments of the present invention relate to a stator vane assembly for use in a compressor of a gas turbine engine.
BACKGROUND OF THE INVENTION
Gas turbine engines are typically utilized to provide thrust to an aerial vehicle or mechanical power to drive an electrical generator. Gas turbine engines comprise at least a compressor, a combustion system, and a turbine, with the turbine coupled to the compressor through a shaft.
A typical compressor comprises a plurality of axially spaced and alternating rows of rotating and stationary airfoils. The rotating airfoils in the compressor are commonly referred to as blades and stationary airfoils are referred to as vanes or stators. Each stage of the blades and vanes decrease in radial height through the compressor as the volume of space decreases. As a result, the air compresses and pressure increases through each stage. The vanes serve to redirect the airflow onto the next stage of blades at the correct incidence angle.
Compressor vanes have an attachment for mounting the individual vanes in the compressor casing. The compressor blades are mounted by an attachment to the rotor while the compressor vanes are mounted by an attachment to the compressor casing. This configuration can be better understood with reference to FIG. 1 , which depicts a portion of a typical gas turbine engine in cross section. The engine 10 includes an inlet 12 , a compressor 14 , a plurality of can-annular combustors 16 , a turbine 18 , a diffuser 20 , and a shaft 22 (not shown) that lies generally coaxial to a centerline A-A. A closer, more detailed view of the compressor section 14 is shown in FIG. 2 .
FIG. 2 depicts a series of alternating rows of blades 24 and vanes 26 . The blades 24 are attached to a disk 28 and extend radially outward towards a compressor case 30 whereas the vanes 26 are attached to the compressor case 30 and extend radially inward towards the centerline A-A.
An example of a prior art compressor vane 26 used in the compressor 14 is shown in FIG. 3 . The compressor vane 26 in FIG. 3 includes two straight hooks 32 located as part of the attachment 34 for mounting the vane 26 in the compressor case 30 . However, the compressor case 30 is annular in shape and the slots 36 extend circumferentially about the case. Therefore, with the vane 26 having straight hooks 32 and the vanes being placed into circumferential slots 36 in the case, the hooks did not sit completely flush in the slots 36 , and as a result a concentrated load occurs at the ends of the hooks 32 .
This straight hook configuration is ideal for manufacturing due to its simple machining techniques and set-up required. Since all surfaces are straight and perpendicular, each vane can be individually machined. However, this arrangement is not ideal for engine operation due to the mismatch between the hooks and slots and the high localized stress that occurs due to this mismatch. As a result of this configuration the compressor vanes vibrate and rattle during engine operation. Any damping that does occur for this design is limited due to the stators being individual (low mass/low inertia) and having limited contact area with the slots for reacting displacement forces. As a result of the increased stress and limited damping, significant wear is exhibited at the compressor vane attachment hooks as well in the circumferential slot of the case. This wear requires premature replacement of the vanes and repair to the case.
SUMMARY OF THE INVENTION
The present invention provides embodiments for a compressor stator vane assembly in a gas turbine engine that addresses the limited damping capability of the prior art vane configuration. In an embodiment of the present invention a stator vane assembly is provided having a plurality of vanes, each vane having an attachment and channels machined into forward and aft walls of the attachment. A forward hook ring segment is pressfit into the channel in the forward wall of the attachment and an aft hook ring segment is pressfit into the channel in the aft wall of the attachment. The hook ring segments in turn engage the grooves in the compressor case, such that the contact area between the hook rings and the compressor case are significantly improved.
In an alternate embodiment, a method of forming a compressor vane assembly is disclosed. The method disclosed provides a means for assembling a plurality of vanes together with a forward hook ring segment pressfit into a channel in the forward face of the attachment and an aft hook ring segment pressfit into a channel in the aft face of the attachment.
In a further embodiment, a method of modifying prior art individual vanes into a compressor stator vane assembly is provided. The method utilizes modifying existing individual vanes having a pair of straight hooks to provide a channel in the forward face of the attachment and a channel in the aft face of the attachment. The method further comprises placing a forward hook ring segment into the channel and an aft hook ring segment into the channel such that each of the hook ring segments are pressfit into the attachment of the vanes to form a vane assembly.
Additional advantages and features of the present invention will be set forth in part in a description which follows, and in part will become apparent to those skilled in the art upon examination of the following, or may be learned from practice of the invention.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING
The present invention is described in detail below with reference to the attached drawing figures, wherein:
FIG. 1 depicts a partial cross section view of a typical gas turbine engine of the prior art;
FIG. 2 depicts a partial cross section view of a portion of the compressor of the prior art;
FIG. 3 depicts a perspective view of a series of vanes installed in the case of the prior art;
FIG. 4 depicts a perspective view of a vane assembly installed in a case in accordance with a preferred embodiment of the present invention;
FIG. 5 depicts a partial cross section view of a vane assembly in accordance with a preferred embodiment of the present invention;
FIG. 6 depicts a partial cross section view of the attachment portion of a vane assembly in accordance with a preferred embodiment of the present invention; and
FIG. 7 depicts a perspective view of a hook ring segment in accordance with a preferred embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
The subject matter of the present invention is described with specificity herein to meet statutory requirements. However, the description itself is not intended to limit the scope of this patent. Rather, the inventors have contemplated that the claimed subject matter might also be embodied in other ways, to include different steps or combinations of steps similar to the ones described in this document, in conjunction with other present or future technologies. Moreover, although the terms “step” and/or “block” may be used herein to connote different elements of methods employed, the terms should not be interpreted as implying any particular order among or between various steps herein disclosed unless and except when the order of individual steps is explicitly described.
Referring now to FIGS. 4-7 , the present invention provides a vane assembly 50 for reducing operating stresses and vibrations in individual vanes. The vane assembly of the present invention comprises a plurality of vanes 52 , each vane having an airfoil 54 and an attachment 56 . The attachment 56 has a first surface 58 adjacent the airfoil 54 and a second surface 60 spaced a distance from the first surface. In the embodiment shown in FIGS. 4-7 , the first surface 58 is generally parallel to the second surface 60 . However, depending on the actual attachment geometry, these surfaces could each have a radius of curvature.
Extending between the first surface 58 and the second surface 60 is a pair of generally parallel and axially extending sidewalls 62 and 64 and a forward wall 66 and aft wall 68 , with the forward and aft walls 66 and 68 being generally perpendicular to the plurality of sidewalls 62 and 64 . Another feature of the attachment 56 is a forward channel 70 in the forward wall 66 and an aft channel 72 in the aft wall 68 . As it can be noted from FIG. 6 , the forward channel 70 and aft channel 72 both have a general “C” shape cross section. Furthermore, the channels 70 and 72 are generally arc-shaped in the direction along the forward and aft walls such that the channels have a radius of curvature. In addition, the channels 70 and 72 are located at approximately the same radial position along the attachment.
The vane assembly 50 also comprises a forward hook ring segment 74 which has a circumferential length and an axially extending hook 76 and an aft hook ring segment 78 which also has a circumferential length and an axially extending hook 80 . The aft hook ring segment 78 is shown in FIG. 7 . The hook ring segments 74 and 78 are used to join the plurality of vanes 52 together into vane assembly 50 . This is possible since the hook ring segments are generally arc-shaped with a radius of curvature corresponding to the arc-shaped channels 70 and 72 .
In order to join the vanes together, the forward hook ring segment 74 is pressfit into the forward channel 70 and the aft hook ring segment 78 is pressfit into the aft channel 72 of the attachment 56 . To assist in the assembly of the hook ring segments 74 and 78 into the attachment, the hook ring segments each have chamfers at approximately a 45 degree angle at the corners of the surfaces that are first inserted into the channels 70 and 72 . The outside edges 70 a and 72 a of the channels are also chamfered.
As one skilled in the art will understand, a pressfit is a means of binding two or more components together through an interference fit along mating surfaces. The exact amount of interference is a function of the design requirements, component materials, and operating conditions. For an embodiment of the present invention, the radial dimensions of the forward and aft channels 70 and 72 , respectively, are slightly undersized compared to the radial height of the forward and aft hook ring segments 74 and 78 , respectively. For the embodiment disclosed in FIGS. 4-7 , this difference in dimension is set for up to 0.0005 inches of interference between the mating surfaces of the hook ring segment and channel. Such an interference fit was set in order to minimize stresses in the attachments 56 yet provide sufficient retention of vanes 52 in hook ring segments 74 and 78 . However, the interference fit could be slightly larger, for example up to about 0.0015 inches without exceeding the material capabilities of the vane attachments. The interference fit also serves to dampen the vibrations in the individual vanes and reduce the amount of displacement that can occur from vane-to-vane during operation.
As previously stated, the hook ring segments join a plurality of vanes together. For the embodiment shown in FIGS. 4-7 , the vane assembly 50 comprises five vanes 52 assembled together by hook ring segments 74 and 78 . However, the quantity of vanes shown in the vane assembly is meant to be merely illustrative and the actual quantity of vanes can vary depending on the engine configuration.
Depending on the engine conditions and compressor case receiving the vane assemblies, it may be desirable to also apply a coating to the surfaces of the hook ring segments that contact the compressor casing. Specifically, this region is radially inward of the axially extending hooks. Applying a coating, such as an Aluminum Bronze, ensures that the wear between the hook ring segments and the compressor case will be directed towards the hook ring segments, as these components can be replaced easier than repairing the large compressor casing out in the operating field.
Once the vanes are assembled with the hook ring segments into the vane assembly 50 , it is ready to be installed in the compressor casing. The vane assembly is held in the casing by the hooks 76 and 80 on the forward hook ring segment and aft hook ring segment respectively. Each vane assembly is intended to abut to an adjacent vane assembly when installed in an engine so as to provide additional damping from assembly to assembly. While it is intended that each vane assembly abuts and adjacent vane assembly, as one skilled in the art will understand, there may be small gaps between adjacent vane assemblies due to manufacturing and/or assembly tolerances. Any gaps that may be present between the vane assemblies are sealed by shim plates.
In an alternate embodiment, a method of forming a compressor stator vane assembly is disclosed in which the method comprises providing a plurality vanes, with each vane having an airfoil 52 and an attachment 56 having a forward wall 66 and an aft wall 68 . Each of the forward wall and aft wall have a channel 70 and 72 therein, respectively.
The method also comprises providing a circumferentially extending forward hook ring segment 74 and a circumferentially extending aft hook ring segment 78 . The method then comprises a step of inserting the forward hook ring segment 74 into the forward channel 70 and inserting the aft ring segment 78 into the aft channel 72 . By inserting the forward and aft hook ring segments into the forward and aft channels, the plurality of vanes are joined together to create a vane assembly with this vane assembly having increased damping capability.
In yet another embodiment of the invention, a method of modifying individual vanes to form a compressor stator vane assembly is disclosed. In this method a plurality of vanes are provided with each vane having an airfoil 52 and an attachment 56 with the attachment having a first surface 58 and a second surface 60 spaced a distance from the first surface 58 and generally parallel thereto. Extending between the first surface 58 and the second surface 60 is a pair of generally parallel sidewalls 62 and 64 and a forward wall 66 and an aft wall 68 , with the forward and aft walls and the sidewalls being generally perpendicular to the first surface and second surface. The attachment is also initially provided with forward and aft hooks 32 (see FIG. 3 ) that are generally parallel to the first and second surfaces.
This method also comprises providing a circumferentially extending forward hook ring segment 74 and a circumferentially extending aft hook ring segment 78 . Since this vane assembly is fabricated from existing individual vane segments, the sidewalls 62 and 64 of the attachment are machined at an angle so as to taper the sidewalls and improve surface area contact between adjacent vane sidewalls. This angle is preferably radial, but can also be a compound radial/axial angle. The existing forward and aft hooks 32 are removed by machining a forward channel 70 having a radius of curvature into the forward wall 66 and machining an aft channel 72 having a radius of curvature into an aft wall 68 of the attachment. Once the vane attachment has been modified to remove the original hooks and incorporate the channels, the forward hook ring segment 74 is inserted into the forward channel 70 and the aft hook ring segment 78 is inserted into the aft channel 72 . These hook ring segments join together the individual vane segments at their attachment to form a vane assembly.
The present invention has been described in relation to particular embodiments, which are intended in all respects to be illustrative rather than restrictive. Alternative embodiments will become apparent to those of ordinary skill in the art to which the present invention pertains without departing from its scope.
From the foregoing, it will be seen that this invention is one well adapted to attain all the ends and objects set forth above, together with other advantages which are obvious and inherent to the system and method. It will be understood that certain features and sub-combinations are of utility and may be employed without reference to other features and sub-combinations. This is contemplated by and within the scope of the claims. | Embodiments for a compressor stator vane assembly in a gas turbine engine are disclosed. In an embodiment of the present invention a stator vane assembly is provided having a plurality of vanes each with an attachment and channels machined into the forward and aft walls of the attachment. A forward hook ring segment is pressfit into the channel in the forward wall of the attachment and an aft hook ring is pressfit into the channel in the aft wall of the attachment. The hook ring segments join a plurality of vanes together so as to provide a uniform engagement of mounting slots in the compressor case. Such an arrangement increases the contact area between the hook rings and the compressor case such that damping of individual vane vibrations are improved and operating stresses are reduced. | 8 |
This application is a continuation of now abandoned application Ser. No. 683,198, filed Dec. 18, 1984.
BACKGROUND OF THE INVENTION
This invention relates to a twin-wire former for a papermaking machine which produces a fiber mat by dewatering a (fiber suspension) material by sandwiching the material between two wire screens (hereinafter "wire screen" is represented as "wire"). This invention particularly relates to improvements in a twin-wire former of the type in which a material is ejected out into a bottom wire which travels substantially horizontally; water is removed out of the material downwardly by means of the foils or the like arranged beneath the wire; and thereafter a top wire which is arranged to sandwich the material by approaching the bottom wire from above and travel downwardly along with the bottom wire on the circumference of a roll provided within the loop of the bottom wire and water is removed upwardly above the top wire.
In the conventional twin-wire former, where the material is sandwiched between two wires, the circumference angle of contact between the wires and the roll, (hereinafter "the wire contacting angle") is fixed. This conventional twin-wire former has a drawback in that formation is deteriorated when the condition of the material to be sandwiched between the wires, for example, thickness or consistency of the material deviates out of a certain range. In addition, in production of thick paper, which needs a large quantity of material to be sandwiched, part of the material is often disadvantageously rejected (toward the upstream side) out of the portion where the two wires come into contact and, travelling in the same direction, press the wet material (hereinunder the portion is represented as "wedge portion"), particularly when the speed of the paper machine is low.
On the other hand, with paper produced by what is called a Fourdrinier machine which forms a fiber mat by removing the water only downwardly with a single wire which travels horizontally, the paper surface facing the wire has fewer fines and less clay, because the fines and clay in the vicinity thereof are washed out. When twin wires are formed by providing another wire (top unit) over the Fourdrinier so as to remove the water upwardly also, it is possible to make the distribution of the fines and the clay in the thickness of the paper more uniform on both sides.
However, the conventional twin-wire former of this type cannot produce paper with good formation over a wide range of basis weight and running speed.
SUMMARY OF THE INVENTION
Accordingly, it is an object of the invention to solve this problem and to obtain a twin-wire former for a paper machine which can produce paper with good formation over a wide range of basis weight, from thin to thick, and at a machine running speed in a wide range, from low to high.
When a pair of wires, namely a top wire and a bottom wire, travel downward on the circumference of a roll for removing the water upwardly through the top wire with a material sandwiched between the wires, as the wire contacting angle on the circumference of the roll is increased, those portions which contain more fiber tend to move to the portions having fewer fibers, which improves the overall formation. However, a wire contacting angle which is too large moves fibers excessively toward the nipping point (in the direction opposite to the traveling direction of the wires), which deteriorates the formation of the paper.
Therefore, it is another object of this invention to improve the formation of paper by adjusting the wire contacting angle within the range in which the formation of paper is not deteriorated.
To adjust the wire contacting angle of the roll, in a twin-wire former according to this invention, a water receiver for receiving the water drawn off to the top wire side, a roll, and suction boxes are made movable.
The above and other objects, features and advantages of the present invention will become clear from the following description of the preferred embodiments thereof, taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side sectional view of a first embodiment of a twin-wire former according to the invention;
FIG. 2 is a side sectional view of the first embodiment of a twin-wire former according to the invention in which the operation state is different from the one in FIG. 1;
FIGS. 3 and 4 are side sectional views of second and third embodiments, respectively, of the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring first to FIG. 1, a material is ejected out of the opening portion of a head box 1 onto a bottom wire 2 travelling substantially horizontally. Within the loop of the bottom wire 2, forming boards 3 and foils 4 are arranged. Vacuum foil boxes 5 for dewatering with a vacuum pressure and by means of the foils 4 are arranged at desired portions. A top wire 6 approaches the material from above to sandwich it between the top wire 6 and bottom wire 2. The run of the pair of wires (twin wires) is directed downwardly around the circumference of a roll 7 which is placed within the loop of the bottom wire 2. Thus the water is drawn off to the top wire side and received by a water receiver 8 which is movable.
A roll 9, which is movable towards or away from the twin-wires, is provided so as to control the wire contacting angle of the roll 7, and similarly movable suction boxes 10 for dewatering by means of vacuum pressure are also provided. Thereafter a couch roll 11 is disposed so that the two wires 2, 6 travel around the circumference of the couch roll 11. A fiber mat is attracted toward the bottom wire 2 by the vacuum pressure of the couch roll 11, and the top wire 6 is released upwardly.
The bottom wire 2 travels substantially horizontally after passing around the couch roll 11 and is directed obliquely downwardly by a wire roll 16. When the bottom wire 2 comes into contact with a felt 18 which is guided by a suction pick-up roll 17 on this slanted portion, the sheet of paper is transferred to the felt 17, whereby it is fed to the next stage. The surfaces of the rolls 7, 9 used for dewatering may be solid, or an open roll made by cutting a groove on the surface thereof and covering a wire of rough meshes may also be used. The roll 7 shown in FIG. 1 is not movable towards and away from the upper or lower wires and is an open roll. The roll 9 may be replaced by a suction roll.
The position of rolls 12, 13 can be adjusted by adjustment mechanisms not shown in the Figure. The rolls 12, 13 control the nipping point of the material where the wet material begins to be sandwiched between the twin wires 2, 6 and the separation point where the top wire 6 is separated from the fiber mat, respectively. The water receiver 8 receives the water drawn off from the wires by virtue of the vacuum pressure. It is preferable to make the water receiver movable towards and away from the twin wires and rotatable around the axis of rotation of the roll 7, as is indicated by the arrow in FIG. 1.
Further, the roll 9 and the suction boxes 10 are also preferably mounted on support means which allows the roll 9 and suction boxes 10 to be movable and rotatable around the axis of rotation of the roll 11, as is indicated by the arrow in Figure 1. The suction boxes 10 which are disposed within the loop of the bottom wire 2 may be disposed in the loop of the top wire 6. In FIG. 2, the roll 9 in FIG. 1 is moved upward along a circular path centered on the axis of rotation of the couch roll 11 and the amount of the wire contacting angle is reduced.
The operation will be explained in the following. The material coming out of the head box 1 is dewatered on the bottom wire 2 in the same way as in the conventional Fourdrinier dewatering section. The amount of drainage and the phenomenon of material jumping on the wire vary depending on the angle of the foils, as is known. Therefore the formation of paper is adjusted by altering a combination and arrangement of a plurality of foils with different angles depending on a type of paper and the operation speed of a paper machine.
In the Fourdrinier machine, since the upper surface of the material is free, the dewatering pressure applied to the material before and after it passes the foils is not high. The retention of fines in the dewatering section of the Fourdrinier is high compared with a former in which the material is sandwiched between the two wires immediately after coming from the head box and is dewatered by members called "shoes" which are similar to the foils.
The angle of a foil and vacuum pressure of the vacuum foil box 5 are adjusted so that the thickness and the consistency of the material may be appropriate for the successive process where the material is sandwiched between the twin wires. Since the material which is sandwiched between the twin wires is first dewatered upwardly on the circumference of the roll 7, the amount of drainage on the upper side is large, which leads to little difference in distribution of fines and clay between the surface facing the bottom wire side and the surface facing the top wire.
As the roll 9 in the twin-wire portion is moved downwardly, the wire contacting angle of the roll 7 becomes large, and thus the amount of drainage also becomes larger. At this time the portion of the material containing more fibers moves to the portion having fewer fibers as it is pressed between the twin wires. This improves the formation.
However, a wire contacting angle which is too large moves fibers in the material sandwiched between the wires in the direction opposite to the traveling direction of the wires up to the upstream side of the wedge portion, which deteriorates the formation of the paper. Therefore, the formation is improved by adjusting the wire contacting angle within the range in which the formation is not deteriorated. Since the dewatering pressure does not fluctuate in the dewatering conducted by the roll 7, unlike the dewatering conducted by rubbing the wires with foils and shoes, the retention of fines is high. The suction box 10 removes further water by vacuum pressure.
The top wire 6 is separated from the bottom wire 2 on the couch roll 11. At this time, the fiber mat is pulled toward the bottom wire 2 by vacuum pressure, which prevents the fiber mat from travelling together with the top wire 6. Generally, in the case of making paper of large basis weight, a smaller degree of pushing down the wire by the roll 9 and accordingly a smaller wire contacting angle than in the case of paper of small basis weight is required to prevent the material sandwiched between the twin-wires from moving in the opposite direction up towards the upstream side of the wedge portion, and hence, the deterioration of the formation.
FIG. 3 shows another embodiment of the invention. In place of the roll 7 shown in FIG. 1, a plurality of supporting blades 14 are arranged such that the surfaces abutting the wire form an arc. The water removed upwardly from the wires 2, 6 is received by a movable water receiver 15. The supporting blades 14 may be in the form of shoes which are used in the known Belbaie former.
The operation with respect to the embodiment shown in FIG. 3 will be described in the following. The further downward the roll 9 is moved, the more often the two wires touch the edges of the supporting blades, whereby the amount of drainage can be increased. At this time the portion of the material containing more fibers moves to the portion having fewer fibers as it is sandwiched between the twin wires. This improves the formation of paper.
However, if the wire contacting angle of the supporting blades 14 which are arranged in an arc-like configuration is too large, the material between the wires moves in the opposite direction up towards the upstream side of the wedge portion. This deteriorates the formation. Therefore, the formation is improved by adjusting the wire contacting angle of the supporting blades 14 of the arc-like arrangement within the range in which the formation is not deteriorated.
When the material between the two wires passes the plurality of supporting blades, the fluctuating dewatering pressure is applied to the material on the edges of the blades a number of times. This dewatering pressure moves the fibers in the material in the micro scale such that the portion with more fibers move to the portion with fewer fibers, thus improving the formation of paper.
In the case shown in FIG. 3, the retention of the fibers with the supporting blades 14 is decreased as compared with the case of applying the roll 7 shown in FIG. 1, but paper with good formation and with less difference in fines distribution between the upper and reverse surfaces can be produced in a wide range of basis weight and a wide range of speed.
In FIG. 4 a fourth embodiment of the invention is illustrated. This embodiment is different from the one shown in FIG. 1 in that a roll 19 is disposed within the loop of the top wire 6 such that the two wires 2, 6 are pressed against the suction zone on the circumference of the couch roll 11. The surface of the roll 19 is preferably covered with soft rubber.
The operation with respect to the embodiment shown in FIG. 4 will now be explained. The fibers between the top wire 6 and the bottom wire 2 are pressed by the pressing force of the roll 19 when they pass between the roll 19 and the couch roll 11. At this time the portion of the material with more fibers moves to the portion with fewer fibers as it is sandwiched between the twin wires. This improves the formation of the fiber mat. The removed water is sucked by the vacuum zone of the couch roll.
As water is removed from the wet material between the two wires, the consistency of the fibers becomes high, and the fibers move with more difficulty. But in the embodiment shown in FIG. 4, it is possible to move the fibers by pressing the fibers strongly between the two wires with the pressing force of the roll 19 within the range in which the formation of paper is not deteriorated. Accordingly, the formation of paper is improved even more.
As has been described above in detail, according to the the present invention, paper with good formation and showing less difference in fines distribution between the top and bottom surfaces can be produced in a wide range of basis weight and speed.
While there have been described what are at present considered to be preferred embodiments of the invention, it will be understood that various modifications may be made therein, and it is intended that the appended claims cover all such modifications as fall within the true spirit and scope of the invention. | A twin-wire former for a paper machine which can produce paper of good formation over a wide range of basis weight and at a speed of wide variation essentially consisting of a top wire and a bottom wire. The bottom wire with a wet material thereon substantially horizontally travels. The top wire approaches the material from above and travels downward together with the bottom wire on the circumference of a supporting member provided in the loop of the bottom wire while pressing the material between the pair of wires. At the position of a force roll provided in the loop of the top wire, the pair of wires commence travelling upwardly through a suction box to a couch roll, where the pair of wires separate from each other. To adjust the wire contacting angle of the supporting member, and hence, to improve the formation of paper, each of a water receiver, the force roll and suction boxes and made movable. | 3 |
CROSS-REFERENCES TO RELATED APPLICATIONS
[0001] This application claims priority to copending U.S. provisional patent application (PPA) Ser. No. 61/696,924, entitled “Universal Docking Bay and Data Door in a Fluidic Analysis System”, filed Sep. 5, 2012. The entire disclosure of the referenced PPA is incorporated in its entirety at least by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention is in the field of fluidic analysis and pertains particularly to methods and apparatus for automating sample analysis.
[0004] 2. Discussion of the State of the Art
[0005] The analysis of fluids such as clinical or environmental fluidic samples may involve a series of processing steps or sequences including those sequences generally involved in chemical, optical, electrical, mechanical, thermal, or acoustical analysis of fluidic samples. Such processes used in fluid metering and analysis, whether incorporated by bench top instruments, disposable cartridges, or in so-called closed fluidic analytic systems are complex and are typically driven by complex algorithmic routines.
[0006] Conventional systems for processing and analyzing fluid samples may employ several fluid chambers, each one specifically configured for subjecting a fluid sample to a particular process step or sequence. The series of steps that can be performed on a fluid sample are typically limited to a sequence of steps performed according to a specific protocol. However, different protocols requiring different kinds of analytic processes require a more versatile approach if a single analytic system is to be employed to perform different types of processing on different types of fluid samples.
[0007] U.S. Pat. No. 8,048,386 issued on Nov. 1, 2011, issued to inventors Dority and Chang, entitled “Fluid Processing and Control”, teaches a modular housing containing multiple chambers for receiving, containing, processing and disposing of a fluid sample. This patent, hereinafter Dority, is incorporated in the instant application by reference.
[0008] The fluid processing and control apparatus taught by Dority enables many different analytic processes to be executed and performed on fluid samples. The system reduces time and effort involved in manual processing, especially where multiple concurrent protocols and different types of processes are required for analysis.
[0009] Further reduction in processing time and manual effort required of system operators might be achieved if additional automation relative to sample identification, sample source identification, process sequence identification, and real-time communication of ongoing process state could be realized.
[0010] Therefore, what is clearly needed in a closed fluidic control and analytic system is one or more universal docking bays for accepting multi-chamber cartridges containing one or more fluidic samples for analysis that overcomes the limitations described above. The instant invention addresses these and other concerns as detailed herein.
SUMMARY OF THE INVENTION
[0011] The present invention is directed to an analytic system comprising a system controller, for example a data door, integrated into the system. The system controller can identify the source of one or more presented samples in a fluidic vessel or cartridge, and what specific processes need to be performed for sample analysis. The analytic system can comprise a universal docking bay for a fluidic vessel or cartridge, for example, as disclosed in U.S. Pat. No. 8,048,386.
[0012] One aspect of the present invention provides for an analytic system comprising a bay having an opening on one side, the bay of a size and shape to enclose a cartridge carrying sample material to be analyzed, one or more mechanisms within the bay through which the cartridge and or material within the cartridge is influenced, a door of a size to cover the opening, a closure mechanism associated with the bay and the door, by which the door is held closed, and an imaging device incorporated in the door positioned and directed such that, with the door in an open position, the imaging device images the presence or absence of a cartridge and a visible indicia affixed on a surface of a cartridge in place in the bay.
[0013] Another aspect of the present invention provides for an analytic system comprising a bay having an opening on one side, the bay of a size and shape to enclose a cartridge carrying sample material to be analyzed, one or more mechanisms within the bay through which the cartridge and or material within the cartridge is influenced, a door of a size to cover the opening, a closure mechanism associated with the bay and the door, by which the door is held closed, and a display on the door, the display visible when the door is closed.
[0014] In another aspect of the invention an analytic method is provided, comprising the steps of (a) placing a cartridge carrying sample material to be analyzed, and one or more bar codes or QR codes, in a bay having an opening on one side of a size and shape to enclose the cartridge, and further having mechanisms within the bay through which the cartridge and or material within the cartridge is influenced; (b) imaging the cartridge by an imaging device incorporated in a door of a size to cover the opening, with the door in an open position, and acquiring by the imaging (i) presence of the cartridge, and (ii) one or more bar codes or QR codes affixed to a surface of the cartridge; and (c) closing the door and securing it closed by a closure mechanism associated with the bay and the door.
[0015] In some embodiments the system further comprises software executing from a non-transitory medium and access to data in a data repository. The software may comprise routines for operating the mechanisms through which the cartridge and/or material within the cartridge is influenced. For example, in some embodiments the mechanisms comprise activation of a rotary valve to align ports through which material is moved within the sample cartridge, and activation of a plunger that creates pressure alterations to urge material to translate between chambers in a sample cartridge.
[0016] In some embodiments the analytic sequence for a cartridge is selected in accordance with a visible indicia affixed to the cartridge in place in the bay. In some embodiments the visible indicia can be a bar code or QR code. The cartridge and operations associated with the cartridge are associated with an individual, and results of operations are stored associated with the individual visible indicia, for example, through a bar code or QR code affixed to the cartridge in place in the bay.
[0017] In some embodiments the door further comprises an electronic display on a side of the door visible to an operator with the door closed. The display may be a passive display and is updated periodically to indicate to an operator one or more of time to completion of an analytic sequence in progress, presence or absence of a cartridge in the bay when the door is closed, or one or more actions required by the operator to further a test sequence. In some embodiments the display may be a touch-screen display updated to present information to an operator, and wherein interactive indices are provided whereby the operator may initiate activities of the system.
[0018] In some embodiments of the method there is additionally a step executing software from a non-transitory medium and accessing data in a data repository. In some embodiments the software accomplishes operating the mechanisms within the bay through which the cartridge and or material within the cartridge is influenced by executing the software. In some embodiments the mechanisms comprise a rotary valve to align ports through which material is moved within the sample cartridge, and a plunger that creates pressure alterations to urge material to translate between chambers in a sample cartridge, further comprising steps for operating the rotary valve and the plunger.
[0019] In some embodiments a plurality of routines are accessed and executed to operate the mechanisms for individual ones of a plurality of analytic sequences, selected according to the nature of the sample material in the cartridge, which may be selected in accordance with a bar code or QR code affixed to the cartridge in place in the bay. The cartridge and operations associated with the cartridge may be associated with an individual, and results of operations may be stored associated with the individual through acquisition of a bar code or QR code affixed to the cartridge in place in the bay
[0020] In some embodiments of the invention the door comprises an electronic display on a side of the door visible to an operator with the door closed and secured by a closure mechanism, and information may be presented on the electronic display to an operator. This display may be a passive display updated periodically to indicate to an operator one or more of time to completion of an analytic sequence in progress, presence or absence of a cartridge in the bay when the door is closed, or one or more actions required by the operator to further a test sequence.
[0021] In some embodiments the door closure mechanism comprises a latch, in some embodiments the closure mechanism can be magnetic, snap-fit or click-fit mechanism, Additional types of closure mechanisms suitable for use with the invention and incorporated herein are well known to persons of ordinary skill in the art,
[0022] Each of the separate embodiments of the invention as detailed herein can be combined with the different aspects of the invention, all of which fall within the scope of the present invention.
BRIEF DESCRIPTION OF THE DRAWING FIGURES
[0023] FIG. 1 is an elevation view of a multi-bay fluidic analysis system according to an embodiment of the present invention.
[0024] FIG. 2 is an elevation view of a multi-chamber sample cartridge for use in the system of FIG. 1 .
[0025] FIG. 3 is an end view of the cartridge of FIG. 2 .
[0026] FIG. 4 is a block diagram illustrating basic system components of the system of FIG. 1 .
[0027] FIG. 5 is a perspective view of a sample cartridge inserted into a cartridge bay of the system of FIG. 1 according to an embodiment of the present invention.
[0028] FIG. 6 is an elevation view of a single bay of the system of FIG. 1 before loading.
[0029] FIG. 7 is an elevation view of the cartridge of FIG. 6 playing a video instruction on an active display.
[0030] FIG. 8 is an elevation view of the bay of FIG. 6 during loading of a sample cartridge.
[0031] FIG. 9 is an elevation view of the bay of FIG. 6 closed after loading a sample cartridge.
[0032] FIG. 10 is an elevation view of the bay of FIG. 6 displaying a test authentication on the active display.
[0033] FIG. 11 is an elevation view of the bay of FIG. 6 during initiation of the procedure authenticated in FIG. 10 .
[0034] FIG. 12 is an elevation view of the system of FIG. 1 depicting a running fluidic analytic sequence.
[0035] FIG. 13 is an elevation view of the system of FIG. 1 depicting a successful conclusion of a fluidic analytic sequence.
[0036] FIG. 14 is an elevation view of the system of FIG. 1 depicting user removal of a sample cartridge after a sequence was determined complete in FIG. 13 .
[0037] FIG. 15 is a block diagram depicting assembled components of a bay data door of the system of FIG. 6 according to an embodiment of the present invention.
[0038] FIG. 16 is a flow chart depicting steps for running one or more fluidic analytic sequences on one or more sample cartridges of the system of FIG. 1 .
DETAILED DESCRIPTION
[0039] The inventors provide a unique system and methods for performing fluidic analytic sequences on fluid samples that enables automatic identification and authentication of ordered procedures as well as notification of procedural state and other information. The present invention is described in enabling detail using the following examples, which may describe more than one relevant embodiment falling within the scope of the present invention.
[0040] FIG. 1 is an elevation view of a multi-bay fluidic analysis system 100 according to an embodiment of the present invention. System 100 includes a housing or framework 101 that can be manufactured of sheet metal, aluminum, a durable polymer, or other suitable materials. Framework 101 includes multiple cartridge bays 103 (A 1 -A 4 ) adapted to dock modular sample cartridges (not illustrated) that contain fluid samples for analysis. System 100 can contain more than four bays or fewer than four bays without departing from the spirit and scope of the present invention.
[0041] Each bay 103 (A 1 -A 4 ) includes an operable bay data door 106 that can be manually and or automatically opened and closed to provide access to internal mechanical components and interfaces adapted to dock with a sample cartridge containing fluidic samples for analysis. Each data door 106 in one embodiment includes a visible electronic display screen 105 (A 1 -A 4 ). Display 105 (A 1 -A 4 ) can be a light emitting diode (LED) display, an organic display, a liquid crystal display (LCD), an electroluminescent display (ELD), or one of a number of types of displays for electronic devices. In some embodiments, display 105 (A 1 -A- 4 ) is a passive display and in some embodiments, the display is a touch screen display capable of recording input in the form of touch by a human finger or stylus depending upon the technology used. In the case of a touch screen, display 105 (A 1 -A 4 ) may be a resistive or a capacitive touch screen, or one of a myriad of other available touch screen technologies such as dispersive signal technology or acoustic pulse recognition.
[0042] In some embodiments, system 100 is a “dumb” system comprising framework ( 101 ) containing multiple bay sites that are adapted to receive independently operational computing modules that include all of the circuitry, CPU facilities, and hardware, including hinged bay data doors, to perform fluidic analytic procedures on fluid samples contained in modular cartridges that may be inserted therein and secured for initiation and performance of automated processing and test result reporting. In some embodiments, system 100 is a computing system having a CPU, memory, and power and communication bus structures. In this case, components of each bay site derive power and instruction from system 100 . In some embodiments, CPU computing power is shared among the displays and the system CPU wherein each module located at each respective bay site has a separate CPU and memory, and wherein each of those peripherals communicates with the primary system CPU and memory and any external systems that might be connected to system 100 .
[0043] Each bay site 103 (A 1 -A 4 ) in some embodiments includes a visual indicator 104 , in this case, an LED that provides procedural state information such as, for example, lighting up when an ordered procedure is running on a cartridge inserted into the bay site. In some embodiments, each bay site 103 (A 1 -A 4 ) has one or more active buttons, switches, or other input mechanisms for the purpose of performing tasks like opening and closing the bay data door, initiating a sequence, clearing a data screen, and so on. In this particular example, displays 105 (A 1 -A 4 ) are touch screen displays that may receive input from a user. Therefore, in the case of active touch screen displays there may not be a requirement for additional input buttons or switches local to a bay site, however the presence or absence of such input mechanisms shall not be construed as a limitation to the practice of the present invention.
[0044] FIG. 2 is an elevation view of a multi-chamber sample cartridge 200 for use in the system of FIG. 1 . Cartridge 200 may be molded from a durable medical grade polymer or other suitable medical grade materials. Cartridge 200 includes a cartridge body 202 , a cartridge base 201 , a cartridge top 203 , and a cartridge alignment feature 206 . Cartridge 200 is adapted for insertion into and mechanical docking by any one of bay sites 103 (A 1 -A 4 ) of system 100 of FIG. 1 .
[0045] Cartridge 200 contains at least one chamber (not illustrated) presenting a fluid sample for analysis. In some embodiments, multiple chambers (two or more) are present within cartridge 200 . In the case of multiple chambers, one or more of the chambers may contain a sample for analysis and one or more of the chambers may be suited as one or more reaction chambers. In some embodiments of multiple chambers disposed within cartridge 200 , one or more of those chambers may contain solid materials such as filter materials, reactant materials, enrichment materials, dispersion materials, or the like. Cartridge 200 may have one or more than one internal chamber without departing from the spirit and scope of the present invention. In some embodiments, chamber 200 may include a detachable reaction chamber disposed externally from cartridge body 202 and fluidically coupled to one or more of the internal chambers disposed within the cartridge body.
[0046] Referring now to FIG. 3 , cartridge 200 is adapted, in some embodiments, to incorporate or receive a cylindrical, rotatable valve 302 containing a fluid displacement region and presenting multiple ports 300 in a rotary valve head capable of being rotated by a mechanical actuator to enable sealed coupling to selected numbers of like ports strategically disposed to interface to the multiple internal chambers in the cartridge body. There are in this exemplary embodiment eight ports 300 sharing a common radius pattern on valve 302 , however there may be more or fewer ports 300 present on valve 302 and some ports may occupy a different radius pattern. The valve may be coupled to one or more fluidic channel coupling mechanisms and may include fluidic vacuum inducing apparatus and fluidic pressure inducing apparatus such as by a piston or by a hydraulically sealed mechanism to draw fluid into and dispel fluid from the fluid displacement region within the valve. In this way, fluids may be processed in one or more than one chamber as well as moved from one chamber to another via selectively coupled ports. Complete analysis of samples may be performed within cartridge 200 docked into any one of bay sites 103 (A 1 -A 4 ) of system 100 without human intervention other than insertion and removal of the cartridge.
[0047] For further detail of construction and operation of cartridge 200 in different exemplary embodiments please refer to the Dority patent incorporated by reference above.
[0048] Referring now back to FIG. 2 , cartridge 200 in some embodiments of the invention includes at least one barcode, such as a (UPC) barcode 207 , and may also include a two-dimensional matrix barcode or quick response (QR) code 205 . Cartridge 200 may be disposable in some embodiments and reusable in some embodiments. In some embodiments, cartridge 200 is pre-loaded with at least one fluidic sample for analysis, and typically such a sample is associated with a particular person. Cartridge 200 is likewise prepared for patient, sample, and test identification purposes with applied stickers presenting the at least one barcode 207 and/or QR code 205 .
[0049] In some embodiments of the invention barcode 207 is associated in a database with a particular patient associated with the biological sample prepared for testing in the sample cartridge. There may be considerable information regarding the particular patient in the dB and information regarding the particular testing and analysis performed by the system using the bar coded cartridge, such as time and nature of the test and test results, for example, may be communicated to the database and stored associated with the particular patient or test subject. As described briefly above, the patient profile and medical information may be stored and updated at any location that is accessible by the communication apparatus associated with the system of the invention, either locally in the analysis unit, nearby by LAN to a server and data repository, or to remote systems reachable through the Internet or other wide area network.
[0050] Analysis may be performed on many different sorts of samples and for many different purposes using cartridges as described herein. Each specific situation will typically require sequencing instructions of the rotary valve and transfer of materials within the cartridge, motivated by movement of a piston in a chamber of the cartridge. The QR code in some embodiments is prepared and applied to the cartridge to indicate the specific processing procedure and timing to be accomplished with the specific cartridge to perform the analysis for the specific type of sample and desired test.
[0051] Further detail regarding the barcode and the QR code, and how they are used, acquired and decoded, and communication with one or more databases is described below.
[0052] Cartridge 200 may also have a visible indicia, for example, a sticker with a generic label, such as a label indicating a condition for which a test or tests are performed to confirm. In some embodiments, a human operator prepares cartridge 200 for insertion into system 100 of FIG. 1 . In some embodiments, cartridge 200 is automatically prepared by a separate automated system which is not illustrated here. Optics incorporated into the data door of each bay site 103 (A 1 -A 4 ) are provided to capture barcodes and/or QR codes, and reader software is provided to decode the information to identify the samples, tests, and source of the samples whether it be a human patient or some other sample source such as an animal or a biologic sample randomly collected from the field, such as from a stream or waterway.
[0053] There are many options for software storage and execution, and for acquisition and storage of test results, other data, and association with patient records. In some embodiments all software storage and execution is local, that is, at the multi-bay analysis system. In some embodiments one or more multi-bay systems may be connected on a local area network (LAN) on which a control server may be also connected, such as, for example, a general-purpose computer. In some embodiments the general-purpose computer may have an interactive interface for a user to command system functions and to display data to the user. In some embodiments data storage and association with patient records and the like may be via the well-known internet network to one or more Internet-connected servers with associated digital data repositories.
[0054] FIG. 4 is a block diagram illustrating basic system components of system 100 of FIG. 1 in one embodiment. System 100 may be adapted as a smart computing system or as a simple framework 101 . In some embodiments framework 101 supports multiple independent computing modules (bay sites 103 (A 1 -A 4 ). In some embodiments, each bay site module is plugged into a back plane 406 . Framework 101 may, in some embodiments, include a central processing unit (CPU) 400 . In some embodiments, the basic circuitry includes an input output (I/O) port 404 to connect the system to a power source, and in some aspects providing power to a peripheral or an external system or device. Framework 101 may also include I/O communication circuitry 402 for enabling computer network access to external systems or other systems on a computer network of systems. In the case of a smart system 100 , an I/O power and communication bus may be provided to connect back plane 406 to power and to CPU 400 and associated resources. Back plane 406 allows communication between independent bay site modules.
[0055] In some embodiments, each bay site module includes an electromechanical controller (EMC) and micro controller 407 ( a - d ). Controllers 407 ( a - d ) are plugged into back plane 406 for power and communication access. In some embodiments, wherein frame 101 includes CPU 400 , a memory block 403 is provided. Memory block 403 may contain any mix of read only memory (ROM), random access memory (RAM), or other suitable memory types that might be required for executing and running software, storing temporary data, and for storing permanent data. In this example, memory block 403 is compartmentalized logically to include memory (MEM- 1 ) for storing laboratory information system (LIS) information such as orders and associated data for approved tests pending. For example, information required to approve and proceed with any test or procedure may be temporarily stored locally for quick sample, test procedure, and patient or sample source identification. In some embodiments the LIS may be directly accessed over I/O port 402 without caching any data.
[0056] Memory block 403 includes a portion of memory (MEM- 2 ) for temporarily storing patient data including, but not limited to patient identification, primary clinical indication (illness disease), medical history summary information, and any other patient data deemed important to store for the purpose of running one or more analytic procedures on behalf of the patient. Sample source identification data may replace patient data in cases where applicable, like in a system that analyzes animal samples, for example. Memory block 403 includes memory for storing temporary state information about the occupancy of bay site modules with sample cartridges 200 . In this example, bay site 103 (A 1 ) and bay site 103 (A 4 ) are occupied with a sample cartridge. Procedural state information may include notification of authentication received for one or more pending procedures, current status of a procedure currently running, notifications of error state or pause state for a running procedure, notification of total time for a procedure and any time left on a running procedure, and notification of successful completion of a procedure. Bay sites 103 (A 2 ) and 103 (A 3 ) are unoccupied by sample cartridges in this example and may present state information via display 105 that they are empty and ready to be used.
[0057] In some embodiments, memory block 403 includes a portion of memory (MEM- 3 ) for storing real-time state information associated with bay site occupancy. Bay mapping data keeps track of all of the bay site occupancy states including sample source identification, patient identifications, procedure identifications, etc. Memory block 403 includes a memory portion (MEM- 4 ) for temporary or permanent storage of Lab routines that may be selected for run one any of the bay sites. In some embodiments where framework 101 is a “dumb” framework, memory for storing data and executing programs and procedures may be included at each independent bay site 103 (A 1 -A 4 ). CPU 400 and memory block 403 are not specifically required in order to practice the present invention. Each bay site 103 (A 1 -A 4 ) may be a fully independent site in terms of CPU processing, analytic testing, and notification and reporting features without departing from the spirit and scope of the present invention.
[0058] In this example, each bay site 103 (A 1 -A 4 ) includes a bay data door logically represented herein as bay data door 412 , shown as open and positioned substantially horizontally. Bay data door 412 is analogous to bay data door 106 of FIG. 1 . In some embodiments, each bay data door 412 for each bay site 103 (A 1 -A 4 ) includes a data display 105 presented outwardly when the data door is closed, an optical device 411 directed inwardly toward the bay that will hold a sample cartridge, the optics a for capturing bar code and/or QR code information, and circuitry 410 for operating the display and optical device. In one embodiment optical device 411 is a digital camera such as a charged coupled device (CCD) or C-MOS imaging device capable of capturing and decoding bar codes and QR codes with the aid of code-parsing software. In some embodiments, camera 411 is a scanner device enabled for optical character recognition (OCR) that automatically activates when a cartridge is inserted in the correct orientation into any of bay sites 103 (A 1 -A 4 ). Circuitry 410 contains all of the circuitry required to operate display 105 , optical device 411 , and any sound card and speakers that might be associated with each independent bay site 103 (A 1 -A 4 ). In some embodiments, each bay site 103 (A 1 -A 4 ) includes all of the electromechanical components to operate each bay site data door 412 and mechanical components for fluid processing relative to a sample cartridge.
[0059] A valve rotary actuator for turning the rotary valve inside the cartridge during fluid processing including moving fluids out of one cartridge chamber and into another cartridge chamber or into a displacement region located within the valve head or in the cartridge as previously described is a part of the system, as is a piston for insertion into the cartridge for urging fluid from chamber to chamber, but neither mechanism is shown here. These mechanisms may be differently placed and operated depending at least in part on the design and geometry of the particular sample cartridge in use and the design of the system that accepts and manipulates the sample cartridge. These mechanisms may be pneumatically or electromechanically operated and are well known to persons of ordinary skill in the art. Although not specifically illustrated here, electromechanically-operated components such as valves, ports, rotary actuators, mechanical extenders, fluid injection apparatus, docking mechanics, and the like may be present and operational at each independent bay site 103 (A 1 -A 4 ). In this way, multiple analytic procedures may be carried out on a sample cartridge without human intervention save for inserting and removing the cartridge.
[0060] FIG. 5 is a perspective view of an exemplary sample cartridge 200 inserted into an exemplary cartridge bay site of the system of FIG. 1 according to some embodiments of the present invention. In this example, cartridge 200 has been prepared with stickers that include one bar code 207 and one QR code 205 . A label 204 identifying a test or set of procedures is also illustrated. In this example, bay data door 412 is open while cartridge 200 is positioned inside the bay site. Optical device 411 is positioned within the data door and protected by a cover 501 , which also covers the display and camera circuitry 410 (see FIG. 4 ). Before data door 412 is closed, camera 411 captures the fact that a cartridge is positioned for test initiation at a bay site. The camera also captures the barcode and QR code data for at least identification and authentication purposes. Element 502 in FIG. 5 represents a portion of an external reaction chamber analogous to chamber 408 of FIG. 4 . In some embodiments, reaction chamber 502 is retractable to within cartridge 200 . In some embodiments, reaction chamber 502 may not be present. In this example, bay data door 412 is hinged at a lower extremity, and can swing open outwardly.
[0061] FIG. 6 is an elevation view of a single bay of the system of FIG. 1 before loading, shown with data door 412 closed with display 105 (A 2 ) visible. In this example, the term “Touch” is displayed within a circle and is indicative of an empty site ready for loading a sample cartridge for processing. In this example, display 105 (A 2 ) is a touch screen display and a user may touch the display to load and present further instruction relative to loading a cartridge for analytical processing. In some embodiments touching the screen at “Touch” will communicate to the software which will react to activate a mechanism to open the bay data door.
[0062] FIG. 7 is an elevation view of display 105 of FIG. 6 playing a video instruction on an active display. Display 105 (A 2 ) has a video presentation loaded for play. A user may initiate play of the video by touching the play icon presented on the screen. The video may be an instructional video covering the process of inserting a sample cartridge into the bay site for processing. In some embodiments, a menu may be presented on display 105 (A 2 ) that provides access to more than one video instruction and or more than one other option for proceeding.
[0063] FIG. 8 is an elevation view of the bay of FIG. 6 , with the data door now open, during loading of a sample cartridge 200 . In this view, a bar code 207 and a QR code 205 ( FIG. 2 ) are visible. A snap-on cover 801 in the bay data door is analogous to cover 501 of FIG. 5 . Hinge plates 803 are also visible in this view. The optical device (not visible here) captures the codes applied to the cartridge during preparation to identify and authenticate the sample source and to select proper test routines to perform on the sample or samples within the cartridge. In this example, the sample is a biologic sample taken from a patient who might have Methicillin-Resistant Staphylococcus aureus (MRSA).
[0064] As described previously with respect to FIG. 5 , the optical device identifies the cartridge and tests required to test for MRSA from the biological sample Likewise, information pertinent to processes performed at any particular bay site is displayed on the display device for that site so an operator may gain real time access to the data and to any instruction when required. The exact analytic processes that might be performed relative to one or more samples within a cartridge are not limited to medical diagnostics and are not relevant to the present invention. DNA analysis including polymerase chain reaction (PCR) processing, genome or exome sequencing, and other kinds of biologic analytic procedures may be performed in any bay site singly or concurrently without limitations. For example, substantially variant procedures may run concurrently in adjacent bay sites on disparate samples without conflict.
[0065] FIG. 9 is an elevation view of the bay of FIG. 6 with the data door closed after loading a sample cartridge. There are several alternative modes of operation that may be executed in different embodiments. In some embodiments the data door may be powered to open and close. The data door, when urged by a user, may close to a first position, and wait for an authentication procedure to verify that the sample cartridge is properly loaded and that the analytical procedure selected by the coding on the cartridge is loaded and ready, then the data door may latch automatically. In some embodiments the data door is opened by the system, but closed by a user. The authentication procedure confirms the information captured and processed from the one or more bar codes and or QR codes applied to the sample cartridge during preparation for analysis.
[0066] The authentication procedure may also confirm that the pending analytical procedure or procedures were pre-ordered and approved. The process is dependent on software that parses the code data captured optically from the sample cartridge and by software that aids in accessing and performing a lookup in a laboratory information system (LIS) or like information system using the code data to match with procedural order information, patient information, and or other data contained in the LIS that can be matched to cartridge data. The results of authentication and confirmation may be displayed for an operating user on display 105 as described in more detail below. One or more audible sounds or beeps may also accompany the data results. The authentication or approval process may depend on one or more conditions such as clear and successful capture of and identification of the data on the cartridge, and clear and successful match of a portion or all of the data to data contained within the LIS or other information system.
[0067] An error in capturing or identifying the barcode or QR code data may result in display of an error message requiring the operator to remove and reinsert the cartridge or to check the optical parameters such as camera view and code sticker integrity. An error in matching data from code to LIS data may result in an error that informs the operator that the pending procedures are not yet authorized, meaning that there may be no current order in the system for that cartridge.
[0068] FIG. 10 is an elevation view of the bay of FIG. 6 displaying an error message that indicates one or more problems leading to a need to abort the test. The error or errors may be any of a number of physical conditions or data discrepancies. The error condition may also be alerted by an audible alert. The operator may be enabled to display further detail about the problems leading to a need to abort by interacting with the touch screen.
[0069] FIG. 11 is an elevation view of the bay of FIG. 6 during initiation of the procedure. In this case an operator has closed the bay data door to a second, latched position. In some embodiments, a magnetic, snap-fit, or click-fit closure mechanism are used. In some embodiments there is only one closed position for the bay data door and the procedure or procedures to be run on the sample within the cartridge are initiated through the touch screen display. In this case, the display may present one or more visible and touch-interactive options for the operator to select. One of the options displayed may be an icon that the operator may select via touch to activate the pending procedure or procedures. There are many different possibilities for enabling initiation of the approved tests at each bay site.
[0070] FIG. 12 is an elevation view of the system of FIG. 1 depicting a running fluidic analytic sequence in bay site 103 (A 2 ) occupied with a cartridge in the process of being analyzed or processed according to the tests or procedures approved in FIG. 9 and initiated in FIG. 11 . Display 105 (A 2 ) depicts a running graphic 1201 that is indicative of a procedure in a running state. A time indication 1202 is displayed on display 105 (A 2 ) that informs the operator of the time remaining for the current procedure. In this case the time is 40:00 minutes. In some embodiments the time indicator decrements according to the timed progression of the procedure.
[0071] In some embodiments of the present invention, a wireless communication component is provided uniquely to each independent bay site and supported by circuitry 410 . Aided by software and user configuration, the wireless communication component may be used to extend the display in real time to the display of a hand-held computing appliance such as a smart phone, iPad, or Notebook adapted for wireless communication and operated by the user. The collection of displays for each bay may be wirelessly communicated to the operator's hand-held device so that the operator may not be required to visually monitor the system from immediately in front of the system.
[0072] Such wireless extension of the display functionality may enable the operator to perform other tasks while procedures are running and then be notified via hand-held display when tasks such as removing and replacing a cartridge and initiating new approved procedures are required. In some embodiments software provided to the hand-held appliance aids in enabling the user/operator to apply touch screen input to the extended display for communication to display 105 (A 1 -A 4 ) and implementation similar to a wireless remote control platform. In some embodiments the hand-held appliance may also communicate with a local or remote database, and there may be interactive features allowing the operator to access and edit data directly without channeling through the bay apparatus. In the example of FIG. 12 LED 104 is lit indicating visually that the bay site is occupied and that tests are being run on the inserted cartridge.
[0073] FIG. 13 is an elevation view of the system of FIG. 12 depicting a successful conclusion of a fluidic analytic sequence. Display 105 (A 2 ) of bay site 103 (A 2 ) indicates that a single or series of test procedures run on the inserted cartridge ( 200 ) are successfully completed. The indications are characterized in this example by time indicator 1202 reading zero time left, and by a visual indicator 1302 in the form of a check mark indicative of a successfully completed test or procedure. LED 104 is lit to indicate that bay site 103 (A 2 ) is still occupied by a cartridge ( 200 ).
[0074] In some embodiments where there is more than one procedure set to run serially, time indicator 1202 may reset for the next procedure. Multiple check boxes may be displayed for multiple procedures set to run serially. As each procedure completes, the check box associated with that procedure might display a check mark. The next procedure will immediately begin and the time indicator for that sequence will display the current time remaining for that procedure. When all of the procedures are completed successfully, all of the boxes will be checked and all of the time indications will read zero.
[0075] In some embodiments where two or more procedures are ordered on one cartridge inserted into a single bay site, a procedure may fail or otherwise not be successfully completed. In this case, the operator may be notified of the error and perhaps be given the option of running the remaining procedures that have not yet been initiated before attempting the failed procedure again. In some embodiments where a cartridge is subject to multiple procedures and the display is a touch screen, the display may depict a procedure scrolling mechanism that the operator may manipulate to scroll through the available procedures and select which ones to perform in serial order. Optionally, one or more of the available procedures may be skipped or left out. In some embodiments using a touch screen, a user may add one or more additional procedures to a list of one or more procedures already indicated for the cartridge. The additional procedures may be added using touch screen input.
[0076] FIG. 14 is an elevation view of the system of FIG. 1 depicting user removal of a sample cartridge after a sequence was determined to be complete in FIG. 13 . In this example, bay site 103 (A 2 ) has been opened after completing one or more procedures successfully. Cartridge 200 is subsequently removed from bay site 103 (A 2 ). LED 104 is now not lit and the user may close the bay data door. Display ( 105 ) will immediately indicate an empty bay site to the operator as described above relative to description of FIG. 6 . In some embodiments, a cartridge that has been successfully processed may be physically stamped or otherwise tagged by the system to help ensure that the cartridge is not reinserted into the system erroneously.
[0077] FIG. 15 is a block diagram depicting assembled components of a bay data door of the system of FIG. 6 according to some embodiments of the present invention. In a preferred embodiment, bay data door 412 includes a basic data door frame 503 . Data door frame 503 includes a window 1502 adapted for receiving display 105 and a pocket 1503 formed behind the window, pocket 1503 enclosing circuitry 410 . In this example, camera 411 is supported by circuitry 410 on the opposite side of the display and is disposed strategically at the center and near the end of the bay data door footprint for data captures. Plastic cover 801 snaps on to data doorframe 503 over circuitry 410 and camera 411 securing them into place in the bay data doorframe while protecting circuitry 410 and camera 411 from exposure to the elements.
[0078] In some embodiments the overall dimensions of display 105 are smaller than the inside dimensions of window 1502 so that the display is fully visible on the face of the data door. The overall dimensions of circuitry 410 are slightly larger than the inside dimensions of window 1502 so that the circuitry bottoms out against the inside wall of the data door. The overall dimensions of snap-on cover 801 are slightly smaller than the inside dimensions of pocket 1503 so that it may be secured over camera 411 and circuitry 410 .
[0079] Each bay data door assembly may be connected for power and communication to the EMC/Micro controller dedicated to that bay site. The controllers drive both the site electromechanical components and site data presentation through the data display on the data door front. In some embodiments, the bay data door is physically opened and closed by the operator. In some embodiments using a touch screen display, the bay data door is opened and closed by command input through the touch screen display. In some embodiments, the bay data door is electromechanically operated to open and close through interaction with the touch screen. In some embodiments, the bay data door is pneumatically operated to open through interaction with the touch screen.
[0080] In some embodiments to complete a bay site independent module, the bay data door with display, camera, and supporting circuitry is wired to an adjacent motherboard supporting the EMC/micro controller, which is plugged into a back plane when installed to the system framework.
[0081] FIG. 16 is a flow chart 1600 depicting, in some embodiments, steps for running one or more fluidic analytical sequences on one or more sample cartridges of the system of FIG. 1 . At step 1601 , an operator prepares one or more than one cartridge for processing. This process may include placement of one or more fluidic samples within the cartridge. In some embodiments, the samples may be contained in chambers that are insertable into pre-specified chamber footprints within the cartridge. In some embodiments, the samples are injected into the appropriate chambers within the cartridge. In this process, the operator places one or more barcode and or QR code stickers on the external cartridge wall that faces the inside of the bay data door when inserted into the bay site. The codes provide data identifying the sample, the sample source, and the ordered procedures to be performed on the sample or samples within the cartridge. In some embodiments all or a part of the tasks represented by step 1601 are performed automatically by equipment not described herein.
[0082] At step 1602 , the operator selects an empty bay site. The display on the bay data door may present an icon or other graphic that signifies that the bay site is empty and ready for a new cartridge. In some embodiments using a touch screen display, the display may be activated at step 1603 , to load and play an instructional presentation at step 1604 , in this case, a cartridge-loading procedure. The instructional presentation may be a video, slide show, or text display. The presentation may include audio instruction in embodiments where speakers are present.
[0083] At step 1605 , the operator opens the bay data door of the bay site selected at step 1602 . In one embodiment using a touch screen display, the operator may open the data door through touch screen command input. In some embodiments, the bay site includes one or more control buttons, one of which may be interacted with to open the data door. In some embodiments, the data door opens manually by interacting with the data door such as pulling the data door out physically, or pushing the data door in to release the data door to automatically swing open. In a preferred embodiment, the bay data door is hinged at the bottom and swings open similar to a drawbridge. In some embodiments the data door may be hinged at the top or at either side. In some embodiments the data door might be a sliding data door.
[0084] At step 1606 , the operator inserts the cartridge, prepared at step 1601 , into the bay site. The operator inserts the cartridge with the barcodes and or and QR codes facing the inside wall of the bay data door, preferably at an opportune angle for the optic device to capture the code data. The angle may be any convenient angle less than 90 degrees and may depend, at least in part, upon the angle at which the camera is mounted on the bay data door. The data door may remain open, partially open, or closed to a first latch position immediately after the cartridge is inserted. At step 1607 , the optical device built into the inside wall of the bay data door captures the coded information on the cartridge and identifies the sample, source of the sample, and the procedures or tests to run on the sample.
[0085] At step 1608 , the operator closes the bay data door. In the case of more than one data door latch position, the operator my “fully” close the bay data door to initiate confirmation or authentication before running analytic procedures. At step 1609 , the system aided by software (SW) accesses a laboratory information system (LIS) and authenticates or confirms the information coded on the inserted cartridge is correct and the procedures are approved for run. Initiation of a procedure or of a sequence of procedures may occur automatically at step 1610 upon test confirmation by the LIS. Various graphics may be presented on the display of the bay data door in a touch screen embodiment, the graphics providing at least visual notification to the operator of one or more states of the process. For example, upon authentication at step 1609 , a graphic of the cartridge may appear on the display indicating that the data was authenticated and the ordered tests will begin.
[0086] At initiation time of a first procedure, a timer is activated that tracks the process time down from an initial and pre-determined amount of time allotted for each procedure. The time allotted for a procedure may be an estimated time that the procedure should occupy, or the exact time it takes for the procedure to run on the system. In any case, the timer ticks down the remaining time as the procedure runs at step 1611 and reads zero when the procedure is complete. At step 1612 , the system determines if the testing is complete for a cartridge that is occupying the bay site. A test may include a single procedure or a sequence of procedures performed in serial fashion. In some embodiments a test may include two or more procedures performed in overlap, or in parallel, or otherwise concurrently.
[0087] At step 1612 , if the system determines that the testing is not complete, the process loops back to step 1611 until the time allotted has run out. At step 1612 , if it is determined that the testing is complete, the operator is prompted to remove the cartridge at step 1613 . The prompt may be displayed on the display screen on the bay data door of the bay site as a short video clip, a pop-up graphic, a text box, or an icon with or without audio. In some embodiments an audio prompt may be played. At step 1614 , the operator opens the bay data door of the bay site and removes the cartridge. The cartridge may then be disposed of or otherwise processed before a next use. At step 1615 , the operator closes the bay data door of the bay site. The display indicates that the site is now empty and ready to receive a next cartridge.
[0088] It will be apparent to one with skill in the art that the universal docking bay of the invention may be provided using some or all of the described features and components without departing from the spirit and scope of the present invention. It will also be apparent to the skilled artisan that the embodiments described above are specific examples of a single broader invention that may have greater scope than any of the singular descriptions taught. There may be many alterations made in the descriptions without departing from the spirit and scope of the present invention. | An analytic system for carrying out a chemical assay, the system having a bay with an opening on one side, the bay of a size and shape to enclose a cartridge carrying sample material to be analyzed, one or more mechanisms within the bay through which the cartridge and or material within the cartridge is influenced, a door of a size to cover the opening, a securing mechanism associated with the bay and the door, by which the door is secured when closed. | 7 |
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This nonprovisional application claims priority under 35 U.S.C. §119(a) on Patent Application No. 2010-233429 filed in Japan on Oct. 18, 2010, the entire contents of which are hereby incorporated by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to an image forming apparatus and, more specifically, to an image forming apparatus having a trial copy function and a control method thereof.
[0004] 2. Description of the Background Art
[0005] Recently, image forming apparatuses including copy machines having various and many copy functions and capable of high-speed copying have been put on the market.
[0006] As the number of functions increases, it becomes difficult to handle skillfully the various and many functions of the device except for users who are familiar with such a device through daily use. Miscopies resulting from errors in operations for setting copy conditions are likely. Even if the user finds the setting error immediately after starting the copy, in a high-speed copy machine, a large number of copies would be taken before the once-started copy operation stops, wasting resources.
[0007] Therefore, high-speed copiers having a “trial copy function” of providing only one copy before outputting a plurality of number of copies, and thereby allowing the user to confirm finished state, have been commercially available. Further, apparatuses having a function of displaying an expected state of an output image (preview function) on a display screen of an operation panel, and thereby allowing the user to confirm, have also been commercially available. Techniques related to copiers having the “trial copy function” and “preview function” are disclosed, for example, in Japanese Patent Laying-Open No. 2007-160790 (hereinafter referred to as '790 Reference).
[0008] '790 Reference discloses a function allowing confirmation of output result before starting copying, by selecting either the “trial copy” or “preview display.” The user selects a desired course from an operation screen image displayed on a display unit of a touch-panel.
[0009] Specifically, on an operation display unit shown in FIG. 2 of '790 Reference, a liquid crystal display unit allowing touch input is provided near the central portion. On the right side of liquid crystal display unit, a group of hard keys (operation unit) including ten keys, an interruption key and a start key is provided, and a hard key for selecting the “trial copy” mode is provided therein. If the trial copy key is operated, the copy executed immediately thereafter will be in the trial copy mode. Specifically, after a document is scanned and read, the image based on the read image is not formed but once displayed as a preview image on the operation screen image (liquid crystal display unit) (see FIG. 6 of '790 Reference). By operating a page feed key (left/right arrows for changing the display page, on the right side of preview image) displayed together with the preview image, it is possible to confirm the preview images by turning the preview images one by one. By touching “print stop” or “print continue” displayed at an upper right portion of the same screen display, it is possible to stop or continue the trial copy mode.
[0010] According to the operation specification disclosed in '790 Reference, keys having “print continue” and “print stop” indications thereon exist on the display screen and, in addition, a “start” key and a “clear/stop” key exist on the operation unit. The “print continue” and “print stop” can also be interpreted as start and stop of printing, respectively. This may leads to user's confusion as to which of the keys on the display screen and the keys on the operation unit are to be operated. Such a situation possibly causes erroneous operations of the user and, hence, there is still a possibility of miscopies, particularly a large number of miscopies in high-speed copiers.
SUMMARY OF THE INVENTION
[0011] In view of the problem described above, it is desirable to provide an image forming apparatus allowing the user to execute the trial copy function in safety, without causing erroneous operation by the user.
[0012] According to an aspect, the present invention provides an image forming apparatus including a display unit that displays an information input screen image allowing input of information, and an input unit that is arranged on the display unit and specifies a designated position on the information input screen image, and having a trial copy function of producing, when an instruction to produce multiple set of copies of a one- or multi-page document is given, a copy or a set of copies to allow a user to confirm that the copy or the set of copies are well; wherein if the trial copy function is designated and a position of one or a plurality of copy start keys displayed on the information input screen image is specified by the input unit, after the copy or the set of copies of the document are provided, the display unit erases the one or a plurality of copy start keys from the information input screen image, and displays a first key for executing the trial copy and a second key for producing copies of remaining number of set number of copies, on the information input screen image.
[0013] Preferably, the display unit changes the one or a plurality of copy start keys to the first key or the second key.
[0014] More preferably, the plurality of copy start keys include a monochrome copy start key and a color copy start key; and the display unit changes the monochrome copy start key and the color copy start key to the first key or the second key.
[0015] Further preferably, the input unit is a touch-panel.
[0016] Preferably, the first and second keys are displayed on an area of the information input screen image including an area where the one or a plurality of copy start keys are displayed adjacent to and parallel to each other.
[0017] More preferably, the display unit displays first help information near the first key or the second key.
[0018] Further preferably, the display unit displays second help information having the first help information of reduced amount, in place of the first help information in a prescribed situation.
[0019] Preferably, the prescribed situation is when a piece of information to be newly displayed on the information input screen image is overlapped on the first help information, or when a position on the first help information displayed on the information input screen image is specified by the input unit.
[0020] More preferably, the display unit displays the first help information in place of the second help information, if a position on the second help information displayed on the information input screen image is specified by the input unit.
[0021] Further preferably, the display unit erases the copy start key from the information input screen image, displays a stop copy key to stop copying on the information input screen image and displays third help information near the stop copy key, in a time period from when the trial copy function is designated until one copy of the document is produced.
[0022] According to another aspect, the present invention provides a method of controlling an image forming apparatus that includes a display unit that displays an information input screen image allowing input of information, and an input unit that is arranged on the display unit and specifies a designated position on the information input screen image, and has a trial copy function of producing, when an instruction to produce multiple set of copies of a one- or multi-page document is given, a copy or a set of copies to allow a user to confirm that the copy or the set of copies are well. The method includes the steps of: determining whether or not the trial copy function is designated; determining whether or not a position on one or a plurality of copy start keys displayed on the information input screen image is specified by the input unit; and if it is determined that the trial copy function is designated and a position on one or a plurality of copy start keys displayed on the information input screen is specified by the input unit, producing the copy or the set of copies of the document, erasing the one or a plurality of copy start keys from the information input screen image, and displaying a first key for executing the trial copy and a second key for producing copies of remaining number of set number of copies, on the information input screen image.
[0023] Preferably, at the step of displaying the first and second keys on the information input screen image, the one or a plurality of copy start keys are changed to the first key or the second key.
[0024] More preferably, the plurality of copy start keys include a monochrome copy start key and a color copy start key; and at the step of displaying the first and second keys on the information input screen image, the monochrome copy start key and the color copy start key are changed to the first key or the second key.
[0025] Further preferably, the input unit is a touch-panel.
[0026] Preferably, the first and second keys are displayed on an area of the information input screen image including an area where the one or a plurality of copy start keys are displayed adjacent to and parallel to each other.
[0027] More preferably, the control method further includes the step of displaying first help information near the first key or the second key.
[0028] Further preferably, the control method further includes the step of displaying second help information having the first help information of reduced amount, in place of the first help information, in a prescribed situation.
[0029] Preferably, the prescribed situation is when a piece of information to be newly displayed on the information input screen image is overlapped on the first help information, or when a position on the first help information displayed on the information input screen image is specified by the input unit.
[0030] More preferably, the control method further includes the step of displaying the first help information in place of the second help information, if a position on the second help information displayed on the information input screen image is specified by the input unit.
[0031] Further preferably, the control method further includes the step of erasing the copy start key from the information input screen image, displaying a stop copy key to stop copying on the information input screen image and displaying third help information near the stop copy key, in a time period from when the trial copy function is designated until one copy of the document is produced.
[0032] According to the present invention, a touch-panel is adopted as the information input device of an image forming apparatus, and in the trial copy mode, a trial copy key and a trial end key are displayed in place of the copy start key normally displayed on the task trigger area. Thus, error of key operation by the user can be prevented.
[0033] Further, when one copy is to be printed as the trial copy, the user instructs copying by the normal copy start key and, thereafter, the trial copy key is displayed on the area where the normal copy start key has been displayed. Therefore, it is possible for the user to instruct trial copy with the same feeling of operation.
[0034] Further, since help information related to the operation is displayed in a balloon near the keys operable in the trial copy mode, error in key operations by the user can further be reduced.
[0035] Further, when a sub-screen (window) for function setting or the like is displayed to receive user operation, the balloon is displayed in a smaller size and, therefore, the balloon does not interfere with the operation by the user. Further, the balloon is not completely erased but left to indicate presence of help information, allowing the user to operate with ease.
[0036] Further, while one copy is printed as a trial copy, unnecessary operation keys are hidden by the balloon and, therefore, error in key operations by the user during printing of one copy can be prevented.
[0037] The foregoing and other objects, features, aspects and advantages of the present invention will become more apparent from the following detailed description of the present invention when taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0038] FIG. 1 is a perspective view showing an appearance of an image forming apparatus in accordance with an embodiment of the present invention.
[0039] FIG. 2 is a functional block diagram showing hardware configuration of the image forming apparatus shown in FIG. 1 .
[0040] FIG. 3 is a plan view showing an information input device provided on the image forming apparatus shown in FIG. 1 .
[0041] FIG. 4 is a flowchart representing a control structure of a program for realizing the trial copy function in the image forming apparatus in accordance with an embodiment of the present invention.
[0042] FIG. 5 is a flowchart representing a control structure of a program for realizing the continuation process shown in FIG. 4 .
[0043] FIG. 6 shows an example of a screen image before the trial copy function is selected, showing the same screen image as that of FIG. 3 .
[0044] FIG. 7 shows an example of a function list displayed when “other functions” key is pressed on the screen image of FIG. 6 .
[0045] FIG. 8 shows an example of a screen image displayed when the trial copy is selected on the screen image of FIG. 7 .
[0046] FIG. 9 shows an example of a screen image displayed when a monochrome start key or a color start key is pressed on the screen image of FIG. 8 .
[0047] FIG. 10 shows an example of screen image displayed after completion of output of one copy, in the trial copy mode.
[0048] FIG. 11 shows an example of a screen image displayed when a trial end key is pressed, in the trial copy mode.
[0049] FIG. 12 shows an example of a screen image displayed when a function setting key is pressed on the screen image of FIG. 10 .
[0050] FIG. 13 shows another example of the screen image displayed after completion of output of one copy, in the trial copy mode.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0051] In the following description and the drawings, the same components are denoted by the same reference characters. Their names and functions are also the same. Therefore, detailed description thereof will not be repeated.
[0052] In the following, embodiments of the present invention will be specifically described with reference to appended figures.
[0053] <Image Forming Apparatus>
[0054] Referring to FIG. 1 , an image forming apparatus 150 in accordance with an embodiment of the present invention includes: a document reading unit 152 ; an image forming unit 154 ; a paper feed unit 156 ; a discharge unit 158 having a paper discharge tray 160 ; and an information input device 162 . Information input device 162 is an operation console causing image forming apparatus 150 to execute prescribed functions, for making various settings related to the image forming apparatus 150 . Information input device 162 has a display unit 164 and an operation unit 166 .
[0055] <Hardware Blocks>
[0056] Referring to FIG. 2 , inside image forming apparatus 150 , a CPU (Central Processing Unit) 180 , an ROM (Read Only Memory) 182 , an RAM (Random Access Memory) 184 and a HDD (Hard Disk Drive) 186 are provided. CPU 180 is for overall control of image forming apparatus 150 . ROM 182 stores programs and the like. RAM 184 is volatile storage. HDD 186 is non-volatile storage that retains data even when power is turned off. ROM 182 stores programs and data necessary for controlling operations of image forming apparatus 150 . Display unit 164 of information input device 162 is formed of a display panel 170 and a touch-panel 172 . Display panel 170 is a display device such as a liquid crystal display, and touch-panel 172 for detecting a pressed position is superposed thereon.
[0057] Image forming apparatus 150 is further provided with an image processing unit 188 , an image memory 190 , a bus 192 and an NIC (Network Interface Card) 194 . CPU 180 , ROM 182 , RAM 184 , HDD 186 , information input device 162 (display panel 170 , touch-panel 172 and operation unit 166 ), NIC 194 , document reading unit 152 , image processing unit 188 , image memory 190 , image forming unit 154 and the like are connected to bus 192 . Data (including control information) are exchanged among these units through bus 192 . CPU 180 reads a program from ROM 182 to RAM 184 through bus 192 , and executes the program using a part of RAM 184 as a work area. Specifically, CPU 180 controls various units forming image forming apparatus 150 in accordance with a program or programs stored in ROM 182 , to realize various functions of image forming apparatus 150 . NIC 194 is connected to an external network 196 , and functions as an interface for communication through network 196 .
[0058] <Information Input Device>
[0059] Referring to FIG. 3 , information input device 162 is formed by integrating display unit 164 and operation unit 166 . Specifically, operation unit 166 includes a home key 240 , a power key 242 and a power save key 244 as hard keys, and a power LED 246 . Power key 242 is for turning on/off the power supply to image forming apparatus 150 . Power save key 244 is for setting image forming apparatus 150 to a power save mode. Power LED 246 is lit when the power of image forming apparatus 150 is turned on. Home key 240 is a key for displaying a home screen image (a screen image on which frequently used functions are registered) on display unit 164 .
[0060] The screen image displayed on display unit 164 includes a function setting area 200 , a preview area 210 , an action panel area 220 and a task trigger area 230 . On function setting area 200 , a plurality of keys (hereinafter also referred to as function setting keys) for setting various functions of image forming apparatus 150 are displayed. On function setting area 200 of FIG. 3 , only a part of function setting keys is displayed. Function setting keys that are not displayed appear if “other functions” key 202 is pressed. Preview area 210 includes a ten key area 212 and a copy number display area 214 . The number of copies is input by the ten keys arranged on ten key area 212 . In FIG. 3 , the number of copies is set to 14.
[0061] On action panel area 220 , pieces of information related to assistance, guidance and suggestion related to the operation are displayed. For instance, if a user selects a specific function, functions related to the selected function are displayed on action panel area 220 . Other functions for objects common to the selected function may be displayed.
[0062] On task trigger area 230 , keys as triggers causing image forming apparatus 150 to start certain processes are displayed. Specifically, a monochrome start key 232 , a color start key 234 , a scan-in key 236 and a CA key 238 are displayed. Monochrome start key 236 is for starting monochrome copy. Color start key 234 is for starting color copy. Scan-in key 236 is for starting a process for once reading a document and providing a preview for copying or for FAX transmission. CA key 238 is for clearing all settings.
[0063] In information input device 162 , the state of image forming apparatus 150 and the job processing status are confirmed, by screen images displayed on display panel 17 Q. By selecting a key displayed on display panel 170 on touch-panel 172 superposed on display panel 170 (pressing the corresponding portion of touch-panel 172 ), function setting or operation instruction to image forming apparatus 150 can be realized.
[0064] In information input device 162 , to determine whether or not a displayed key is pressed, known technique may be used. By way of example, correspondence between two-dimensional coordinates of touch-panel 172 and two-dimensional coordinates of display panel 170 is determined beforehand, and whether or not the position pressed on touch-panel 172 is included in any area of a letter or a figure displayed on display panel 170 is determined.
[0065] <Software Configuration>
[0066] In the following, a process in which information input device 162 is operated by the user and image forming apparatus 150 realizes the trial copy operation will be described. In the following, various processes are realized by CPU 180 executing programs read from ROM 182 . In the following, that a prescribed area displayed on display panel 170 (for example, a key) is pressed means that a corresponding portion of touch-panel 172 is pressed.
[0067] Referring to FIG. 4 , if the trial copy function is selected, at step 300 of the program for realizing the trial copy, CPU 180 displays information indicating that the operation is in the “trial copy” mode, on the screen image displayed on display panel 170 .
[0068] The trial copy function can be selected from function setting area 200 displayed on a first screen image 600 of FIG. 6 . Specifically, on the first screen image 600 , if other functions key 202 is pressed, a second screen image 610 shown in FIG. 7 is displayed. In FIG. 7 , on a function list display area 612 of the second screen image 610 , a list of functions is displayed. Since not all functions are displayed, a scroll bar 614 for scrolling the list display is displayed on the right side of function list display area 612 . In the second screen image 610 , if an area having the indication of “trial copy” is pressed, the trial copy function is selected. Here, selection is indicated by a thick line in FIG. 7 . In this state, if a basic setting key 616 is pressed, display of function list display area 612 ends, and a different screen image is displayed. Specifically, a third screen image 620 shown in FIG. 8 is displayed. The third screen image 620 is substantially the same as the first screen image 600 shown in FIG. 6 , except that there is an indication 622 of “trial copy in progress” on the upper left portion of the screen image.
[0069] With the third screen image 620 being displayed, at step 302 , CPU 180 determines whether or not color start key 234 has been pressed. If color start key 234 is pressed, control proceeds to step 304 . At step 304 , CPU 180 sets a parameter M for designating an image formation mode to “1”. Thereafter, control proceeds to step 306 . If color start key 234 is not pressed, control proceeds to step 330 . Parameter M is stored, for example, in RAM 184 .
[0070] At step 330 , CPU 180 determines whether or not monochrome start key 232 has been pressed. If monochrome start key is pressed, control proceeds to step 332 . At step 332 , CPU 180 sets the parameter M for designating the image formation mode to “0”. Thereafter, control proceeds to step 306 . If monochrome start key 232 is not pressed, control proceeds to step 340 .
[0071] At step 340 , CPU 180 determines whether or not CA key 238 has been pressed. If CA key 238 is pressed, control proceeds to step 342 . At step 342 , CPU 180 cancels the trial copy mode, and the present program ends. If CA key 238 is not pressed, control returns to step 302 .
[0072] At step 306 , CPU 180 decreases the numerical value in a copy number display area 214 of the third screen image 320 by “1”. Further, at step 308 , CPU 180 changes the display of task trigger area 230 on the third screen image 620 . Specifically, CPU 180 displays a fourth screen image 630 shown in FIG. 9 . In the fourth screen image 630 , the number of copies is changed to “13”, and monochrome start key 232 and color start key 234 are changed to stop copy key 632 . At the same time, a first balloon 638 including help information (information indicating the state of image forming apparatus 150 and information assisting the operation by the user) is displayed to hide scan-in key 236 .
[0073] At step 310 , in accordance with the value of parameter indicating the image forming mode, CPU 180 controls document reading unit 152 , image processing unit 188 , image memory 190 and image forming unit 154 and thereby reads the document and executes color copy (when M=1) or monochrome copy (when M=0). Here the image data obtained by reading the document is stored in image memory 190 , and used when copy is taken at a subsequent step.
[0074] With the fourth screen image 630 being displayed, at step 312 , CPU 180 determines whether or not stop copy key 632 is pressed. If stop copy key 632 is pressed, control proceeds to step 314 . At step 314 , CPU 180 stops copying and on the fourth screen image 630 , returns the copy number and the display of task trigger area 230 to the original state (that is, to the third screen image 620 ). Thereafter, control returns to step 302 . If stop copy key 632 is not pressed, control proceeds to step 316 .
[0075] At step 316 , CPU 180 determines whether or not one copy (trial copy) is completed. If the one copy has not yet been completed, control returns to step 310 and if completed, control proceeds to step 318 . In this manner, through steps 310 , 312 , 314 and 316 , if a stop operation is made by the user during copying one trial copy, the one copy is stopped.
[0076] At step 318 , CPU 180 changes the display in the task trigger area of the fourth screen image 630 , and after executing the continuation process of step 320 , ends the present program of realizing the trial copy function. Specifically, at step 318 , CPU 180 displays a fifth screen image 640 shown in FIG. 10 , and waits for a user operation. When we compare the fifth screen image 640 with the preceding fourth screen image 630 , it can be seen that stop copy key 632 is changed to trial end key 642 , the first balloon 638 is erased and trial copy key 646 is displayed at that portion. In the fifth screen image 640 , a second balloon 648 including help information for assisting user operation is displayed. When we compare the fifth screen image 640 with the first screen image 600 and the third screen image 620 , it can be seen that monochrome start key 232 and color start key 234 are changed to trial end key 642 , and scan-in key 236 is changed to trial copy key 646 .
[0077] Referring to FIG. 5 , at step 500 of the program for realizing the continuation process at step 320 , with the fifth screen image 640 being displayed, CPU 180 determines whether or not trial copy key 646 has been pressed. If trial copy key 646 is pressed, control proceeds to step 308 and if not, control proceeds to step 510 .
[0078] Steps 310 , 312 , 316 and 318 shown in FIG. 5 , executed if trial copy key 646 is pressed, are the same as steps 310 , 312 , 316 and 318 of FIG. 4 . Therefore, description thereof will not be repeated here. It is noted that step 502 executed if stop copy key 632 is pressed with the fourth screen image 630 being displayed at step 312 is different from step 314 shown in FIG. 4 . At step 502 , CPU 180 simply stops copying, and the number of copies is not returned to the original value. Thereafter, control proceeds to step 318 .
[0079] At step 510 , with the fifth screen image 640 being displayed, CPU 180 determines whether or not trial end key 642 has been pressed. If trial end key 642 is pressed, control proceeds to steps 512 to execute copying of remaining number, and if not, control proceeds to step 520 .
[0080] At step 512 , CPU 180 changes the display of task trigger area 230 of the fifth screen image 640 . Specifically, CPU 180 displays the sixth screen image 650 shown in FIG. 11 . In the sixth screen image 650 , trial end key 642 of the fifth screen image 640 is changed to stop copy key 632 , and the second balloon 648 is erased. Further, a third balloon including help information indicating that copying is in progress is displayed on trial copy key 646 .
[0081] At step 514 , in accordance with the value of parameter M indicating the image forming mode, CPU 180 controls image processing unit 188 , image memory 190 and image forming unit 154 and executes color copy (when M=1) or monochrome copy (when M=0), to provide the remaining number of copies (here, 13 copies). Every time printing of one copy ends, CPU 180 decreases the number of printing displayed on the screen image by “1”. Here, since image data read and stored in image memory 190 at step 310 is used, document reading unit 152 is not driven.
[0082] With the sixth screen image 650 being displayed, at step 312 , CPU 180 determines whether or not stop copy key 632 has been pressed. If stop copy key 632 is pressed, control proceeds to step 502 . At step 510 , CPU 180 stops copying, and on the sixth screen image 650 , returns the display of task trigger area 230 to the original state (that is, to the fifth screen image 640 ). Thereafter, control returns to step 302 . If stop copy key 632 is not pressed, control returns to step 516 .
[0083] At step 516 , CPU 180 determines whether or not copying of the remaining number of copies has been all completed. By way of example, using a parameter representing the number of copies displayed on the screen image, by decreasing the parameter value by “1” every time one copy is printed, it is possible to determine whether all copies have been completed, by checking whether or not the parameter value is “0”. If not all copies have been completed, control returns to step 514 . If all copies are completed, the control returns to the main routine and the present program ends. In this manner, through steps 514 , 312 and 516 , if a stop operation by the user is received while the process of copying the remaining number is being executed, the copy operation is stopped.
[0084] At step 520 , CPU 180 determines whether or not a function setting key in function setting area 200 of the fifth screen image 640 has been pressed. If any function setting key is pressed, control proceeds to step 522 . At step 522 , CPU 180 displays a corresponding setting screen image, and waits for user operation. FIG. 12 shows an example when a magnification key is selected as the function setting key. On a seventh screen image 660 shown in FIG. 12 , a magnification setting window 662 is displayed overlapped on the fifth screen image 640 , and in place of the second balloon 648 , a fourth balloon 668 is displayed. When magnification setting window is displayed, the second balloon interferes with the view and, therefore, the fourth balloon 668 including only the information that the second balloon 648 exists and not the specific help information, is displayed.
[0085] Setting of copy magnification using magnification setting window 662 is realized by pressing a key of percentage indication and thereby directly designating the magnification, or by designating a numerical value in the range of 25 to 400 by pressing up and down keys 664 . After the completion of setting, magnification setting window 662 is closed (for example, the sign “x” at the upper right corner is pressed), and then the display returns to the fifth screen image 640 , in which the second balloon 648 including the help information appears in place of the fourth balloon 668 .
[0086] In this manner, if trial end key 642 or trial copy key 646 is pressed after a function setting key is pressed and the function setting is changed, the copy process is executed in accordance with the changed conditions, at step 310 or at step 514 .
[0087] Step 340 of determining whether or not CA key 238 has been pressed, and step 342 executed if CA key 238 is pressed, are the same as steps 340 and 342 shown in FIG. 4 . Therefore, description thereof will not be repeated here. It is noted, however, that at step 340 shown in FIG. 5 , if CA key 238 is not pressed, control returns to step 500 .
[0088] As described above, when the user uses the trial copy function and makes one copy at first, it is possible for the user to start copying by pressing the normal copy start key (monochrome start key 232 or color start key 234 ) displayed on the task trigger area. Copy instruction thereafter can be given by using trial end key 642 and trial copy key 646 , which are different from the normal copy start keys, displayed on the task trigger area. Specifically, the user evaluates the result of one copy, and if it is unsatisfactory, he/she may change setting by using the function setting key or keys, and then by pressing trial copy key 646 , the user can repeat printing one copy until satisfactory result is obtained. After the satisfactory finish is obtained, the remaining number of copies can be taken by pressing trial end key 642 . In this manner, since the keys related to trial copy are displayed in place of normally displayed keys in the task trigger area, erroneous operation by the user can be reduced, and the user can safely execute the trial copy function.
[0089] Further, in the trial copy mode, help information is displayed in a balloon in or around the task trigger area and, therefore, erroneous operation by the user can further be reduced.
[0090] In the foregoing, an example has been described in which monochrome start key 232 and color start key 234 of the third screen image 620 are changed to trial end key 642 in the fifth screen image 640 , and scan-in key 236 of the third screen image 620 is changed to trial copy key 646 in the fifth screen image 640 . The example, however, is not limiting. By way of example, a trial end key 702 and a trial copy key 706 may be displayed as shown in the eighth screen image 700 of FIG. 13 . In the eighth screen image 700 , the positions of trial end key and trial copy key are reversed from the fifth screen image 640 . Specifically, in the eighth screen image 700 shown in FIG. 13 , monochrome start key 232 and color start key 234 of the third screen image 620 are changed to trial copy key 706 , and scan-in key 236 of the third screen image 620 is changed to trial end key 702 .
[0091] Further, the positions for displaying the first to fourth balloons are not limited to the positions described above. Specifically, the first balloon 638 and the third balloon 658 displayed during the copying operation are used for displaying the state of image forming apparatus 150 and, besides, for hiding unnecessary keys displayed in the task trigger area. Therefore, the first and third balloons 638 and 658 may be displayed in any manner provided that keys other than stop copy key 632 and CA key 238 that may be operated during the copying operation are hidden. These balloons may be displayed with the size and position changed appropriately in accordance with the key arrangement in the task trigger area.
[0092] Further, the condition for displaying the second balloon 648 in a smaller size such as the fourth balloon 668 is not limited to the condition described above (when function setting is to be done), and it may be displayed in a smaller size when a different condition is satisfied. For example, the second balloon 648 may be displayed in a smaller size if it is pressed; or if a prescribed time passes after the second balloon 648 is displayed.
[0093] Further, the condition for returning the displayed small fourth balloon 668 to the original second balloon 648 is not limited to the condition described above (when function setting is completed). By way of example, the second balloon 648 may be displayed if the fourth balloon 668 is pressed.
[0094] Though an image forming apparatus capable of monochrome copy and color copy has been described as an example, it is not limiting. For instance, the image forming apparatus may have the monochrome copy function only and may not have the color copy function. In that case, the color start key is not displayed on the display panel and a simple copy start key (corresponding to the monochrome start key) is displayed. When the trial copy function is to be executed, the copy start key may be changed to the trial copy key or to the trial end key.
[0095] The embodiments as have been described here are mere examples and should not be interpreted as restrictive. The scope of the present invention is determined by each of the claims with appropriate consideration of the written description of the embodiments and embraces modifications within the meaning of, and equivalent to, the languages in the claims. | An image forming apparatus includes a display device that displays an input screen image and a touch-panel arranged on the display device, and has a trial copy function of producing, when instructed to produce multiple copies of a document, a copy or copies to allow the user to confirm that the copy or copies are well. When the trial copy function is designated and a copy start key displayed on the input screen image is pressed, the image forming apparatus produces one copy or copies of the document, erases the copy start key from the input screen image, and displays a trial copy key, a trial end key and a balloon including help information. Since keys related to the trial copy are displayed in place of normally displayed keys, operation errors can be reduced and the user can easily execute the trial copy function. | 6 |
CROSS-REFERENCE TO RELATED U.S. APPLICATION
This document is a continuation-in-part of application Ser. No. 372,661, filed June 28, 1989, now abandoned.
TECHNICAL FIELD
The present invention deals broadly with the field of electronics and electronic devices. More narrowly, however, it deals with the field of structures and methods for reducing noise emanating from transmission lines interconnecting electronic devices or connecting an electronic device to a power source. Specifically, the invention is directed to apparatus and a method for filtering a transmission line or cable at an appropriate location therealong.
BACKGROUND OF THE INVENTION
Propagation of radio frequencies is particularly desirable under some circumstances. The classic case of desirability is where a radio broadcast facility intends to transmit a radio wave into the atmosphere. In such a case, an antenna having a particular length and structure compatible with the wavelength and frequency of the waves to be transmitted is designed and constructed. The antenna is constructed specifically in order to maximize propagation of the wave.
While in the broadcasting scenario maximization of transmission is desirable, it is, at best, undesirable, and at worst, totally unacceptable, in other scenarios. The advent of the computer, including personal computers, and other equipments such as dedicated wordprocessors and electronic telephone systems has given light to circumstances where transmission of radio frequencies from transmission lines is undesirable. Power cables and transmission lines radiate radio frequencies for some distance into spaces which electronic equipments, of which the power cables and transmission lines are a part, occupy. Under some circumstances, there is no great problem because the frequencies are not radiated sufficient distances to create noise problems for other equipments. Typically, equipments in adjacent spaces are positioned so that noise problems are not made apparent.
In other circumstances, significant noise detriment can occur. This is often significantly true when an equipment generating RF noise has a power cable which plugs into a conventional wall outlet at the same location at which a wall outlet in an adjacent space is positioned. There can be a direct transmission of the noise from a generating equipment, along its power cable to its wall outlet, and directly through to the other side of the wall and into a power cable of an equipment in the adjacent space. When this occurs, a damaging effect results upon the operation of the equipment receiving the RF noise. For example, if the equipment is a computer, the effects upon operation of the computer may immediately become apparent in viewing the CRT.
There are two kinds of noise that can be generated. The first is conducted noise. Such noise is transmitted axially along the length of the transmission line. The second type is radiated noise; radiated noise emanates radially outwardly from the transmission line as would radio transmissions from, for example, a commercial radio station antenna.
While conducted noise can do much damage, it is often not as major a problem as is radiated noise. Consequently, those in the industry are, typically, not as concerned about conducted noise as they are about radiated noise. The problem can become critical, however, because conducted noise can become radiated noise if allowed to traverse cables or transmission lines.
Because of problems that have developed in the industry over the past decade or so, national agencies in various countries have implemented regulations and requirements which must be met by electronic equipments placed on the market.
Various attempts have been made to solve the problems created by conducted and radiated noise. One attempted solution has been to try to filter each individual pin of, for example, a D subminiature connector which functions to connect a data transmission line. The attempted filtering of each individual pin is, however, complex and, consequently, expensive. Even when filtering of this nature is able to be accomplished, the result is less than optimum, since such filtering does not effect filtering of noise on the cable shield.
Another attempted solution has been to place an annular ferrite sleeve over the transmission line or cable itself. Typically, however, such sleeves are brittle. Consequently, in view of their generally exposed disposition, they can become cracked, broken, and, as a result, unable to perform their intended function. Further, no magnetic shield is provided over the sleeve to eliminate magnetic interference to nearby components such as cathode ray tubes.
Additionally, when such a solution is sought, aesthetic problems result. An obtrusive appendage makes a product employing such a sleeve unsightly.
A further problem that is encountered when seeking to implement a ferrite sleeve solution is that of location. Sleeves that are affixed to a transmission line locate the sleeve some distance from the interconnecting pins thus leaving exposed or unfiltered lengths of transmission line causing radiation. Another problem encountered with the prior art is that the sleeve is often not captive but can move down the transmission line rendering it ineffective.
It is to these problems and desirable features dictated by the prior art that the present invention is directed. It is both an apparatus and method for reducing radio frequency noise emanating from a transmission line, without incurring the drawbacks of the prior art.
SUMMARY OF THE INVENTION
The present invention includes both apparatus and method embodiments. The apparatus includes a ferrite core which is received and held internally within a connector plug at at least one end of a transmission line interconnecting electronic devices. The ferrite core is disposed to surround, within the connector plug, all conductors, comprising a bundle which forms the transmission line, going to various connections of the connector plug. The core, thereby, is able to cut-off and reduce the noise immediately proximate its source.
A connector plug has an axial dimension of a certain length. In a preferred embodiment of the invention, the ferrite core is provided with an axial dimension less than that of the connector plug.
In order to facilitate positioning of the ferrite core within the connector plug and encircling a bundle comprising all conductors going to various connections of the plug and other conductors, one embodiment envisions a ferrite core which is bifurcated along a plane to divide the core into two substantially equal-in-size, generally symmetrical portions. The plane of bifurcation is such that it extends generally axially. Consequently, the bifurcated portions of the core are able to be disposed on opposite sides of the bundle of the conductors.
With the ferrite core positioned in this manner, a series inductor is created in each conductor passing through the ferrite. Additionally, a small RF bypass capacitor is created from each conductor to ground.
A cable shield and each conductor, in combination with the ferrite core and connector plug shell, function to form the capacitors. The cable shield is located outside the conductors yet Within an axial channel through the ferrite core through which the conductors pass. The shield and conductors form one plate of the capacitors.
The ferrite core, having a dielectric constant of between 15 and 500,000, insulates the connector shell from the cable shield and conductors. The shell forms the other plate of the bypass capacitors.
As discussed above, the shield and conductors form one plate of the capacitors, and the other plate (the connector shell) is connected to ground. Thus, a simple integrated, distributed series of LC filters is created because of the inherent properties of the ferrite core.
The filtering of each data line is to a much lesser degree than that of the shield in view of the much smaller inner plate area. Wave shape integrity is, thereby, achieved in view of the large amount of filtering on the cable shield with only a slight amount of filtering on each data line.
It is envisioned that the ferrite core in accordance with the present invention would be produced so that its outer surface would substantially conform to an inner wall of the connector plug defining a cavity within the plug in which the core can be received. By so producing the core, it can more securely be held within the connector plug without undesired movement resulting or separation of core halves.
The apparatus invention further envisions employment of clip means for grounding any shielding and for holding the bundle comprising the conductors going to various connections of the connector plug, tightly against the inner wall of the plug. By properly providing such clip means, exact positioning of the bundle of conductors within the ferrite core can be facilitated.
The method embodiment includes steps of providing a ferrite core having an outer surface substantially conforming to an inner wall of the connector plug shell which defines a cavity therewithin, and disassembling the connector plug by separating half portions of the plug to expose the bundle of conductors within the plug. Such conductors go to the various connections of the plug. With the connector plug so disassembled, the ferrite core is seated within one of the halves of the connector plug with one side of the core received so that its outer surface is cradled by the wall of the half portion of the plug.
The bundle of individual conductors is, thereafter, passed through a central, axially-extending channel in the ferrite core. The plug is, then, reassembled by securing the two halves of the plug shell together.
The ferrite core provided as the second step of the method, can be bifurcated along a plane extending generally axially with respect to the axis of the transmission line connector plug. Insertion of the core within the plug can, thereby, be facilitated.
The present invention is thus an improved apparatus and an improved method for reducing radio frequency noise emanating from a transmission line interconnecting electronic devices. More specific features and advantages obtained in view of those features will become apparent with reference to the DETAILED DESCRIPTION OF THE INVENTION, appended claims, and accompanying drawing figures.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a D subminiature connector, as typically used in connecting computer components, with which the present invention is used;
FIG. 1a is a fragmentary sectional view taken generally along line 1a--1a of FIG. 1;
FIG. 2 is an exploded assembly view in perspective illustrating the connector shown in FIG. 1 and the core in accordance with the present invention;
FIG. 3 is a rear elevational view of the connector plug shown in FIG. 1;
FIG. 4 is a rear elevational view of the core in accordance with the present invention;
FIG. 5 is a rear elevational view of an alternative core; and
FIG. 6 is a perspective exploded view illustrating a half portion of the connector plug shell and a clip employed to ground shields and to secure a bundle comprising the conductors of the transmission line, to the half of the shell.
DETAILED DESCRIPTION OF THE INVENTION
Referring now to the drawings wherein like reference numerals denote like elements throughout the several views, FIG. 1 illustrates a D subminiature connector plug shell 10 as is known in the prior art. Similarly, FIG. 2 shows a similar connector in an exploded presentation to illustrate the manner of use of the present invention.
Such connector plugs are known in the prior art. They serve the purpose of mating a transmission line cable 12, typically, comprising multiple data conductors, for transmitting data from one component of a computer to another. For example, a connector might function to mate one end of the transmission line cable 12 to a central processing unit (CPU) (not shown). The other end of the transmission line cable 12 could also be provided with a similar D subminiature connector. That end of the cable 12 could be connected to, for example, a printer (not shown).
As seen in the figures, a shell defining the connector plug 10 comprises two portions 10', 10". Each portion 10', 10" is a half of the plug 10 lying on one of opposite sides of a plane of bifurcation. The plane of bifurcation extends generally axially with respect to the axis of the overall connector plug. It can be seen, with reference to FIG. 2, that the transmission line 12 can be brought into the plug 10, therefore, by separating the shell halves 10', 10".
The cable 12 comprises a plurality of conductors such as transmission wires, shielding, etc., each of the conductors going to a different one of the male pins 16 of the connector 10 and shields connected to shell ground. Such wires can be mated to their corresponding pins 16, for example, by soldering or other appropriate processes.
It will be understood that in conventional off-the-shelf connectors of the type illustrated in the figures, no filtering or inclusion of RF attenuation means is provided within the plug 10 to filter cable shields, and no ferrite capacitors are formed to provide additional filtering. While filtering of individual pins 16 has been attempted, most solutions to the noise problem typical of transmission lines 12 used with electronic equipments have focused upon the provision of a sleeve at some point along the length of the transmission line cable 12.
As previously discussed, the shell of the connector plug 10 comprises two portions 10', 10". As seen in FIGS. 2 and 6, an interior wall 18 of the lower shell half 10" is provided with contours in view of the nature of the plug 10. For example, a pair of opposed lands 20 extend inwardly into the cavity 22 defined within the shell 10, from the sides thereof. These lands 20 are provided to define apertures 24 through which bolts 26 to secure the two shell halves 10', 10" together can be disposed.
FIG. 2 shows an upper shell portion 10' which is substantially a mirror image of the lower shell portion half 10". The upper portion 10', therefore, has corresponding lands, each of the lands corresponding to a related land 20 in the lower shell portion 10". When the two shell portions 10', 10" are brought into mating engagement, apertures 24 in the related lands 20 will be in registration so that a bolt 26 can pass completely therethrough and a nut 28 be threadedly secured onto the shank portion of the two bolts 26.
At a mating end 30 of the connector plug 10, each shell portion 10', 10" is provided with a pair of appendages 32 which relate to corresponding appendages on the opposite shell portion. An axially extending hole 34 is defined in the connector 10 when the shell portions 10', 10" are mated together. These holes 34 function to receive securing screws or bolts (not shown) which allow secure retention of the connector plug 10 to the electronic equipment with which it is used.
FIGS. 1, 2, and 6 also illustrate a latch 36. Such a latch 36 serves to maintain retention of the pin housing to the connector housing.
FIG. 1a illustrates a manner in which upper and lower shell portions 10', 10" of the connector plug 10 can be fitted with respect to one another. The upper portion 10' is shown as having an outer flange tab 38 which is received in a recess 40 in the lower shell portion 10" of the shell 10. By mating the portions 10', 10" together in this manner, a seal against entry of dirt and other particulate matter into the interior of the connector plug 10 is afforded.
The present invention, as shown in FIG. 2, comprises a split ferrite core 42 which is receivable within the connector plug body 10. An outer surface 44 of the core 42, as seen in FIG. 2, is configured to substantially conform to the inner wall 18 defining a cavity 22 within the plug 10.
As previously discussed, the inner wall 18 is irregular in accommodating the lands 20 for mating, etc. The core 42 shown in FIG. 2 is produced to have side indentations 46 which conform to these lands 20.
In order to facilitate closure of the core 42 over the bundle comprising the conductors, it (the core) can be bifurcated along a central, generally axially-extending plane (as at 48). This plane, it is intended, is substantially parallel to the plane of bifurcation of the connector plug shell 10.
In view of the bifurcation of the core 42 in a manner as described, production would be such so that, when the two core portions 42', 42" are mated together, they would, aggregatedly define an outer surface 44 conforming substantially to the inner wall 18 of the connector plug 10, and inwardly the core halves would mate perfectly.
FIG. 2 illustrates a sleeve 50 which would, typically, be elastomeric in nature. The sleeve 50 can be fitted about the transmission line cable 12 at a location therealong whereby the sleeve 50 would surround the cable 12 at a location along its length which passes through a central aperture 52 in the core 42. The bundle of conductors is, thereby, protected against pinching, sharp bending, etc.
FIG. 6 shows a clip 54 which can be employed to provide cable strain relief and shield grounding. The clip 54 is shown as having a central bowed portion 56 which would pass over the bundle of conductors and shield and thus secure them to the wall 18 of the shell portion defining, in part, the cavity 22 in which the core 42 is received.
As seen in FIG. 6, the central bowed portion 56 of the clip 54 can be registered with a cradle recess 58 molded into the lower shell half 10" to accommodate passage of the bundle of conductors. Additional lands 60, having internally threaded apertures 62, can be provided in order to enable the clip 54 to be secured to the shell half 10". Appropriate screws 64 are passed through the apertures 66 in the clip 54 and into the internally threaded apertures in these lands 60.
In inserting the core 42, the connector plug 10 would be opened by removing the appropriate bolts 26 or other securing means so that the shell halves 10', 10" could be unmated. With the plug 10 opened in this manner, a first portion 42" of the ferrite core 42 would be inserted into the appropriate location within the lower connector plug half 10". This could be done by maneuvering the core half 42" until it were easily fitted into position.
The bundle of conductors would then be fed, along with the protective sleeve 50, into a position wherein the bundle were cradled in the lower half of the central aperture 52 in the core 42. The bundle, it will be understood, will extend axially through the cradle recess 58 that registers with the central, bowed portion 56 of the clip 54. The clip 54 can then be secured into place.
Thereafter, the upper half of the core 42' would be fitted over its corresponding lower half 42". With the core 42 thusly encircling the bundle of conductors, the upper portion 10' of the connector plug shell 10 would be closed over the lower portion 10" and secured in place by the bolts 26 and their associated nuts 28.
As previously suggested, the core 42 is formed from ferrite, a compound formed from a strong base and ferric oxide which exists in alkaline solution. It has been found that this particular compound is proficient in attenuating radio frequency noise first conducted and then radiated outwardly from a transmission line or cable.
With the ferrite core 42 located as discussed above, a series inductor is created in each conductor passing through the core 42. Additionally, a small RF bypass capacitor is created from each conductor to ground. The formation of the small capacitors is unique with the present invention.
A cable shield encircling the various data conductors, disposed within the central aperature 52 in the core 42, functions as one of a plurality of first plates of the various capacitors. The data conductors function as first plates of other capacitors.
The ferrite, having a dielectric constant of between 15 and 500,000 forms an excellent dielectric. The connector shell 10, enveloping the ferrite core 42, forms the other plate of each of the capacitors.
Thus, a simple, integrated distributed series of LC filters is created. This advantage is inherent in positioning the core 42 with respect to the shell 10 and shield and conductors in a manner as defined hereinbefore.
Filtering of each data line is to a lesser degree than is filtering of the shield. This is because each data line has a much smaller area than does the shield. A large amount of filtering on the cable shield and only small amounts on each data line, however, is a situation which is sought to be achieved. As a result, wave shape integrity is maintained.
It will be understood that the discussion hereinbefore is with reference to a connector shell functioning as one capacitor plate. The invention, however, does encompass numerous varied applications wherein a ferrite core 42 is enclosed by a grounded or terminated outer metallic cover, both the metallic cover and the ferrite core 42 encircling various conductors to contain unwanted RF noise.
Numerous characteristics and advantages of the invention have been set forth in the foregoing description. It will be understood, of course, that this disclosure is, in many respects, only illustrative. Changes can be made in details, particularly in matters of shape, size, and arrangement of parts without exceeding the scope of the invention. The invention's scope is defined in the language in which the appended claims are expressed. | A device for filtering radio frequency noise emanating from one or more axially extending conductors. The device includes a conductive shell which is spaced axially from the conductor or conductors. A ferrite core is fitted intermediate, and in engagement with, both the conductor or conductors and the shell. The ferrite core, thereby, functions to provide substantially increased series impedance in the conductor or conductors and to concurrently provide a common dielectric for multiple distributed, bypass capacitors along the conductor or conductors. | 7 |
FIELD OF THE INVENTION
The present invention relates to a new and useful fast curing thermosetting adhesive comprised of cross-linked binary phenol-formaldehyde and lignin and additionally, an adhesive which can be rendered "pre-cure" resistant, as well as the methods of preparing same. The fast curing and "pre-cure" resistant adhesive may be used in the preparation of manufactured lignocellulosic products such as boards and panels employing sawdust, wood chips, wood wafers and the like.
BACKGROUND OF INVENTION
Phenol-formaldehyde (PF) adhesive resins have long been used as thermosetting binders in the preparation of manufactured boards or panels. Numerous attempts have been made to develop suitable substitute adhesives, which utilize wood waste, in order to not only meet growing environmental concerns, but to also reduce the dependence upon petroleum based constituents, the availability and cost of which is increasingly uncertain.
These attempts have included efforts to develop suitable adhesive binders by using PF to cross-link other possible adhesive constituents, including one or more waste products of wood processing. Unfortunately, to data these efforts have met with only limited success.
The range of wood waste products which have been successfully cross-linked is limited, and the methods used to produce these adhesive binders have been slow and laborious, often requiring pretreatment of the waste product constituent. Furthermore, the cure time and adhesion characteristics of these adhesive binders have been such that widespread use or acceptance of these substitutes by the manufactured board industry has not occurred. For example, it is often the case that the adhesive binder must be used under acidic conditions. However, board and panel manufacturers prefer to operate in an alkaline environment, since less wear and tear is encountered by production equipment.
In U.S. Pat. No. 2,786,008 issued on Mar. 19, 1957--Herschler, an adhesive binder consisting of phenol-formaldehyde (PF) and ammonium based spent sulphite liquor (NH 4 SSL) is disclosed. In addition to producing an acidic adhesive which is slow curing, the method disclosed by Herschler is laborious and time-consuming, as it is necessary to make the alkaline PF "acid tolerant" in order to avoid precipitation of the PF resin upon mixing of same with the acidic spent sulphite liquor.
Another example of using PF to cross-link a wood waste product is that disclosed in U.S. Pat. No. 4,113,675 issued on Sep. 12, 1978--Clarke et al., wherein methylolated lignin was cross-linked by an acid catalyzed low molecular weight PF resin. It was observed that kraft lignin was itself not sufficiently reactive to under significant cross-linking with PF, and that it was thus necessary to pre-react the lignin with a methylolating agent, such as formaldehyde, so as to introduce methylol groups to the lignin molecule. Moreover, it was indicated that in order to achieve satisfactory cross-linking on curing, the pH of the binder must be acidic. Finally, the adhesive disclosed in Clarke et al. was found to be relatively slow curing.
In Canadian patent 1,214,293 issued on Nov. 18, 1986--Calve et al., an adhesive consisting of ammonium based spent sulphite liquor (NH 4 SSL) cross-linked by a commercial PF is disclosed. It was found that while PF normally precipitates when in acidic solution with NH 4 SSL, a useful adhesive could be obtained if the NH 4 SSL-PF were maintained in dispersion through rigorous stirring or agitation. Again, acidic conditions, of pH 3 to 7, were required to provide acceptable modulus of rupture (MOR) test results on waferboard and particleboard manufactured with the adhesive.
In U.S. Pat. No. 4,127,544 issued on Nov. 28, 1978--Allan, a process for the partial substitution of ammonium lignosulfonate for phenol in alkaline phenolic-aldehyde resin adhesives is described. However, the NH 4 SSL is first pre-reacted with phenol at a temperature range of 150°-300° C. under autogenous pressure prior to condensation with formaldehyde under alkaline conditions. The reaction at high temperature and pressure is expensive. Also, no wood adhesive bond test data were provided.
In U.S. Pat. No. 4,324,747 issued on Apr. 13, 1982--Sudan et al, a resin where an alkaline phenol-formaldehyde resin is simply mixed with a kraft pulping liquor and use to bond waferboard is disclosed. The phenolic resin is prepared by refluxing phenol and formaldehyde in the presence of zinc acetate or heating at lower temperature in the presence of calcium oxide. No reference to adjustment of molecular weight distribution of the phenolic resin or example of addition of ammonium salt is provided. This type of resin is slow curing and not "pre-cure" resistant.
To be acceptable for industrial use, a new adhesive must meet certain criteria. For example, it must be available as a spray dried powder or stable liquid; be quick setting if it is employed as a core adhesive for thick multi-layer panels where the resin is far from the heating source, or be "pre-cure" resistant if it is employed for bonding a monolayer panel or the face of a multi-layer panel. If the resin cures prematurely while the mat is resting on a hot caul plate before pressing or at first contact with the press platens before sufficient pressure is applied to consolidate the mat, a poor bond will ensue.
In the aforementioned examples and elsewhere, it has not been suggested or contemplated that the PF component of the adhesive be modified or specially constituted to enhance the cross-linking of the wood waste product component of the adhesive.
While a two component or "binary PF" resin, comprised of a mixture of high average molecular weight PF and low average molecular weight PF components, has long been used in the manufacture of board, heretofore, the low molecular weight PF has been added to enhance resin flow with minimum dry-out. Its unique reactivity to produce a quick setting resin when used in combination with wood waste, especially polydisperse lignin, has not been recognized and its use in combination with wood waste product not contemplated.
For example, in U.S. Pat. No. 4,269,949 issued on May 26, 1981--Hickson et al, there is disclosed a binary PF resin comprised of a mixture of high and low molecular weight resins, particularly suitable for use in hardboard applications, owing to the minimum dry-out exhibited by the adhesive.
In U.S. Pat. No. 4,433,120 issued on Feb. 21, 1984--Chiu, it was demonstrated that a liquid binary PF resin having low viscosity and low surface tension could be used for efficient spray application as fine droplets in waferboard manufacture. The liquid binary PF resin has limited pre-cure resistance due to the presence of the slower curing low molecular weight phenolic resin which is however not sufficient for a surface resin. Although the liquid binary PF resin exhibited some pre-cure resistance, this resin is relatively expensive to produce, and displayed only limited pre-cure resistance. It is also difficult to spray-dry without advancing the resin and reducing its pre-cure resistance.
In a recent study Stephens and Kutscha (Wood and Fiber Science, 19(4), 1987, pp. 353-361) fractionated a phenol-formaldehyde resin into a high and low molecular weight resin by ultrafiltration and compared the adhesive properties of each fraction to the unfractionated PF resin. They found that: "the high molecular weight resin fraction performed nearly as well as the unfractionated resin". The presence of low molecular weight phenol-formaldehyde only slightly improve the characteristic of the PF resin, and is not essential to the process.
SUMMARY OF INVENTION
On the contrary to previous findings, it has been found that a mixture of a binary PF and a polydisperse lignin, shows an unexpected high adhesive reactivity.
While in previous work, different types of phenolic resin were required, for example, with kraft or sulphite lignin which have different molecular weight distribution, in accordance with this invention results better than previous were obtained with a binary PF resin cross-linker for the lignin and independently of the lignin origin. While high molecular weight PF resin could be used alone as adhesive, with a wood waste product such as lignin, the presence of both high and low molecular weight phenolic resin is needed to produce a fast curing adhesive composition and a strong weather resistance joint. The use of high or low molecular weight PF alone with a wood waste produce such as lignin, results in a weak bond, while a balance composition of high molecular weight PF, low molecular weight PF and lignin has been found to result in an adhesive with curing and strength properties similar to a fast curing commercial phenolic resin. Both high and low molecular weight PF cross-link the lignin which is itself a mixture of high and low molecular weight particles. The small phenolic molecules are also believed to link the high molecular weight lignin polymer as the resin is cured while the large phenolic molecules link the smaller lignin molecules. This system can also be used under acidic conditions, as a water solution or dispersion.
It has also been found that the lignin, as well as their uses as a water dispersion, improves the facility of spray drying of the phenolic system resulting in a higher yield. This is regarded as important since a resin which spray drys more easily can be produced at a higher rate, increasing productivity.
In accordance with yet another aspect of this invention, the inexpensive resin can also be made to exhibit improved pre-cure resistance which is important when used as a liquid or spray-dried powder face adhesive for three-layer composite products, such as waferboard.
This was achieved by simple mixing a phenol-formaldehyde resin (one which could be used as core adhesive for a 3-layer panel, for example), a relatively large quantity of a lignin and an ammonium salt. The use of ammonium spent sulphite liquor is preferred as lignin source as it already contains the ammonium salt component. If kraft, steam hydrolysed, organosolv, SSL of other cooking base or glucose was employed, the resin flow and pre-cure resistance is capable of being controlled by addition of ammonium hydroxide and ammonium salt such as ammonium sulphate, ammonium p-tolenesulfonic acid or ammonium chloride. The use of low molecular weight lignin is often preferable as it will help to control the flow of the resin. Upon addition of sodium hydroxide or a strong base other than ammonium hydroxide, the resin was found to loose some of its pre-cure resistance. Although the presence of a lignin is much preferred, it was also found possible to slightly improve the pre-cure resistance of a phenolic resin by adding directly to it an ammonium salt. The use of a binary PF resin is preferred for pre-cure resistance in the presence of lignin and ammonium salt.
As indicated above, the present invention contemplates using binary PF to cross-link wood waste lignin in order to provide a novel quick-curing thermosetting adhesive. By employing a binary PF, it is not necessary to include the additional step of pretreating (by methylolation) lignin as was the case in Clarke et al (supra.). Furthermore, contrary to the results indicated in Canadian Patent 1,214,293, it has been found that sodium based spent sulphite liquor (NaSSL) can be employed as an adhesive component where binary PF is utilized. Importantly, satisfactory results are obtainable where the adhesive is employed under alkaline, as well as acidic, conditions. Not only is the adhesive of the present invention relatively simple to produce, but it is also quick-curing, easy to spray-dry and demonstrates improved adhesion characteristics.
An adhesive having the foregoing quick or fast curing qualities is produced by reacting preferably by mixing the binary PF in solution with lignin which advantageously, can be obtained from wood, pulp, waste, such as that produced in the sulphite, kraft, organosolv or steam hydrolysed pulping process (of course mixing the various ingredients by powder to powder blending is also possible). As previously noted, the binary PF consists of a mixture of high average molecular weight PF (high MW PF) and low average molecular weight PF (low MW PF). As indicated herein, binary PF has been found to be an effective cross-linker for the aforementioned lignins to produce a quick-curing adhesive having improved adhesion characteristics.
Preferably, either the low MW PF is mixed with the lignin prior to mixing with the high MW PF, or, the high MW PF and the low MW PF are mixed concurrently with the lignin.
The adhesive system can be used as an alkaline water (aqueous) solution (pH 9-11) by simple mixing of the alkaline binary PF with the lignin copolymer and slight addition of a base such as sodium hydroxide if required to increase the resin solubility or by utilization of a binary PF having a concentration of low MW PF, for example, 85% low MW PF and 15% high MW PF. Excessive addition of sodium hydroxide will result in advancing the resin particularly during spray-drying, and reducing its adhesive properties. As well, the pH of the solution can be lowered to disperse the adhesive (pH 3-9), or the adhesive may be separated from the solution, or spray-dried. Slight improvement in lignin-PF reactivity has been observed if the lignin-PF mixture is heated at low temperature (for example 2 hours at 50° C.), prior to spray-drying.
The weight ratio of the high MW PF to the low MW PF can be from 1:1 to 9:1, and is preferably in the area of 7:3, but where an acid water solution is preferred, the ratio can be 1:9 to 1:4, preferably 15:85.
The average molecular weight of the high MW PF is preferably from 1,200 to 10,000, and the average molecular weight of the low MW PF is from 200 to 1,200. The weight ratio of binary PF to lignin may be from 9:1 to 1:9, preferably 80:20.
The weight ratio of the binary PF to lignin can range from 9:1 to 1:9 and is preferably 85:15 for the production of a quick setting adhesive.
The rendering of the adhesive "pre-cure" resistant contemplates the addition of an ammonium salt to a PF resin to provide a novel pre-cure resistant thermosetting adhesive. This type of adhesive is primarily intended for use as a face adhesive for three layer waferboards. Employing a binary PF for this type of resin is preferred. A face or a core PF resin (preferably core PF as more PF could be replaced with lignin) presently used for the manufacture of waferboard can be used. The amount of lignin and/or ammonium salt, and the choice of PF copolymer will determine the rate of curing of the adhesive and its pre-cure resistance. As before, the adhesive can be transformed into a useful adhesive powder by spray drying and is generally employed under alkaline conditions.
To produce the "pre-cure" resistant adhesive, as before, a PF in solution (and which preferably a binary PF) is mixed with a lignin which advantageously is in waste form and recovered from one of the different pulping processes, and an ammonium salt. As previously noted, the ammonium salt may consist for example of ammonium lignosulfonate, ammonium sulphate, ammonium p-toluenesulfonic acid or ammonium chloride.
The ammonium salts are generally acidic and will cause precipitation of the alkaline phenolic resin upon mixing. This may be prevented by concurrent slight addition of ammonium hydroxide. Again excessive addition of strong base other than ammonium hydroxide such as sodium hydroxide will reduce the flow and pre-cure resistance of the resin. The content of ammonium salt (salt other than ammonium spent sulphite liquor) in the resin mixture may vary from 1 to 30% based on the total dry weight of the resin mixture and is preferably 2-6%.
In the case of NH 4 SSL, the salt being also the lignin copolymer, the PF to NH 4 SSL weight ratio can vary from 8:2 to 1:9 and is preferably 70:30. The preferred weight ratio is also 70:30 for lignin sources other than NH 4 SSL such as for example, sodium or calcium based SSL or steam hydrolysed lignin. If a strongly alkaline kraft lignin is being used, it has been found that by removing part of the sodium salt content of the kraft lignin by precipitation of the lignin in acidic solution and washing with a dilute acid water solution, may be preferable, in order to avoid formation of excess of sodium hydroxide in the final resin mixture. It is also possible to formulate a phenolic resin with less sodium hydroxide to accommodate this copolymer.
As for the quick setting adhesive, the pH of the resin solution can be lowered to disperse the adhesive (pH 3-9) but it is preferably used as a water solution (pH 9-11). The resin may be spray dried into a stable powder or used as a liquid.
An important aspect of these findings is that the lignin as well as most ammonium salts are inexpensive in comparison to phenol-formaldehyde. Also important is the increase in the quantity of material recovered if spray-dried into stable powder per hour employing existing equipment, a further reduction in the adhesive production cost.
A further advantage of this finding is that the lignin and ammonium salt in a composite panel, during thermosetting, will react with any free formaldehyde present in the resin formulation and thus act as a formaldehyde scavenger.
BRIEF DESCRIPTION OF DRAWING
FIG. 1 is a graphic representation of the relationship between the percentage yield and particle size of the adhesive in powder form obtained after spray drying, and the percentage of binary PF and/or NH 4 SSL present in the adhesive mixture before spray drying. It should be noted that the 100% NH 4 SSL and PF were sprayed as a water solution while all the PF-NH 4 SSL mixture were spray-dried as a dispersion at a pH of 5.0. It should be added that similar high yield (89% powder recovery based on initial resin dry weight) obtained using a resin containing kraft lignin (27%)-(NH 4 ) 2 SO 4 (3%)-PF(70%). The resin was spray dried as a water solution at a pH of 9.8.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
In the following, the method of preparing the adhesives of the invention are described. As well, test results including assessments of the adhesion characteristics of various adhesive formulations are set forth.
THE BINARY PF RESINS
There are several examples in the literature of method of preparation of binary PF resins (Ex. U.S. Pat. Nos. 3,180,784; 3,267,188; 3,591,535; 3,927,140; 4,269,949; 4,345,054; 4,433,120). As already mentioned, the unique reactivity of binary phenolic resin to produce a quick setting resin when used in combination with lignin has not been recognized. The intent is not to show how to produce a binary PF since this art has already been described in the literature, but to provide examples of binary resin formulations which could be used to demonstrate their unique reactivity when employed with wood waste products such as lignin or containing lignin.
EXAMPLE OF PREPARATION OF A BINARY PF RESIN
For the preparation of high MW resin: P-formaldehyde (167 g) was suspended in water (378 g) and heated at 95° for 30 minutes. The mixture was then cooled to 25° C. and phenol (210 g) was added followed by slow addition of sodium hydroxide (62.5 g at 50 percent solid). The temperature of the reaction was raised to 90° C. in a 60 minutes period and held until the resin reached a (Brookfield) viscosity of 50 cps (viscosity measured at 25° C.). The resin was cooled to 75° C. and held at this temperature until a viscosity of 300 cps was obtained. At this point the resin was cooled to room temperature and 10 g of sodium hydroxide was added. The resin had a weight average molecular weight (Mw) of 4,000 and a number average molecular weight of 1314 as measured by gel permeation chromatography (polyethylene glycol calibration).
For the preparation of the low MW resin: P-formaldehyde (148 g) was suspended in water (220° C.) and heated at 95° C. for 30 minutes. The mixture was then cooled to 25° C. and phenol (210 g) was added followed by slow addition of sodium hydroxide (30.8 g at 50 percent solid). The temperature was raised to 60° C. and held at this temperature until a Brookfield viscosity of 35 cps was obtained. At this point the resin was cooled to room temperature and sodium hydroxide (25 g) was added.
Obviously the preparation of a binary PF is not restricted to these examples. For example, a high molecular weight PF could be obtained by a using a gradient temperature starting at 60° C. and increasing to reflux and the order of addition of the various ingredients may be changed. Alkaline catalyst other than sodium hydroxide may be employed.
It is also possible to produce a binary phenolic resin in a single process instead of separately producing the low and high molecular weight components and mixing. For example, an aqueous solution of phenol, formaldehyde and a catalyst such as sodium hydroxide can be treated at a temperature of about 95° C. and for a time sufficient to produce the high molecular weight PF component. Following cooling, additional phenol, formaldehyde and catalyst is added to this component and heated within a temperature range from about 40° C. to about 65° C. for a time sufficient to generate the low molecular weight PF component of the binary PF. It is also possible to reverse the two process steps by producing the low MW PF component prior to the high MW PF component.
MIXING OF BINARY PF AND LIGNIN
An adhesive solution may be prepared by first adding the low MW PF to the lignin, and then adding the high MW PF to the mixture of low MW PF and lignin, or the low MW PF and high MW PF may be added concurrently to the lignin. Adding high MW PF directly to the lignin may result in precipitation. Following reacting the binary PF and lignin preferably by mixing, the pH of the solution may be adjusted by adding hydrochloric acid or sodium hydroxide. Optimum adhesive properties for NH 4 SSL as the lignin component were obtained when mixed with a weight ratio of 30% low MW PF to 70% high MW PF and at a pH of 3 to 10.5.
It is also possible to add the lignin during the single process production of the high and low MW PF previously described with the lignin during the first or second stage of the binary PF production, or both. The cross-linking reaction between the lignin and binary PF is accelerated with the application of heat and thus it is possible to effect cross-linking when an aqueous solution of the binary PF and lignin is spray dried to create a dry adhesive powder.
MIXING OF PF, LIGNIN COPOLYMER AND AMMONIUM SALT
A pre-cure resistant adhesive solution is prepared by mixing ammonia, preferably ammonium salt, and more preferably an ammonium acid salt with lignin and then adding the PF resin while stirring vigorously. Addition of the ammonium acid salt directly to PF will cause its precipitation into a gummy mass rendering it difficult to work with. The mixture of PF, lignin and ammonium salt can be used as an alkaline solution by adjusting to pH 9-11 with ammonium hydroxide. The pre-cure resistance can be adjusted by varying the solid weight ratio of PF, lignin and salt.
The single process technique of producing binary PF with or without the addition of lignin thereto as above described can also advantageously be modified if it is desired that the thermosetting resin also exhibit pre-cure resistance. For example, ammonia, preferably in the form of an ammonia salt can be added with the second stage addition of phenol, formaldehyde and catalyst necessary for the production of the low molecular weight component in the binary PF. Moreover, the temperature gradients, quantities of addition and sequence of addition of the ingredients can also vary and depending upon the intended end use or characteristics of the adhesive (face or core applications and if it is to be made pre-cure resistant or not).
EXAMPLE 1
In this example, the adhesive properties of NH 4 SSL-PF adhesives having either a high molecular weight or a low molecular weight PF component are compared with a resin prepared by mixing in a 1 to 1 weight ratio a binary PF resin and NH 4 SSL with the results being set forth in Table 1.
TABLE 1__________________________________________________________________________Effect of PF Resin Molecular Weight onNH.sub.4 SSL (50%)-PF(50%) Adhesive Properties Board Properties.sup.a Torsion Press MOR Shear Cycle Density (MPa) (N · m)Resin Type (min.) kg/m.sup.3) Dry Wet IB MOE Dry Wet__________________________________________________________________________Low MW PF.sup.b 4 663 21.7 0 0.280 4290 7.5 0 5 667 24.9 10.5 0.380 4310 11.0 1.8High MW PF.sup.c 4 669 16.5 0 0.209 3776 5.5 0 5 660 16.8 0 0.245 3916 5.6 0Low MW PF (50%).sup.c + 4 676 25.4 12.9 0.378 4695 10.7 1.6High MW PF (50%) 5 667 26.5 13.4 0.418 4510 11.3 2.9Low MW PF (50%).sup.d 5 663 25.0 11.8 0.405 4410 10.9 2.2High MW PF (50%)__________________________________________________________________________ .sup.a Waferboard pressed at 210° C. .sup.b Solution at pH5. .sup.c Dispersion at pH5. .sup.d Dispersion at pH 9.5
As the results in Table 1 indicate, the adhesive containing the binary PF yielded a better quality waferboard in comparison to an adhesive having either only a low average molecular weight or high average molecular weight PF component. Both wet and dry MOR (modulus of rupture), and MOE (modulus of elasticity) results were superior for the binary PF-NH 4 SSL adhesive under both acid and alkaline conditions and exhibited comparatively higher IB (internal bond strength) values. Torsion shear test results also confirm the superiority of the binary PF-NH 4 SSL adhesive under both acid and alkaline conditions. Torsion shear test results also confirm the superiority of the binary PF-NH 4 SSL adhesive. Of particular note is that satisfactory adhesion characteristics are noted for the binary PF-NH 4 SSL adhesive under both acidic and alkaline conditions.
EXAMPLE 2
In the following example, an assessment of the relative efficacy of a commercial PF resin (not a binary PF) and a binary PF resin as a cross-linker for methylolated kraft lignin (MKL) was made with the results set forth in Table 2. As indicated by the superior MOR and IB values, under both acid and alkaline conditions MKL was cross-lined with the binary PF to provide an adhesive yielding a waferboard having properties superior to waferboard prepared when a commercial PF was used as MKL cross-linker.
TABLE 2______________________________________Comparison Between a Commercial PFand Experimental Binary Phenolic Resin asCrosslinker for Methylolated Kraft Lignin (MKL).sup.1,2 Board Properties MOR (Mpa)Resin Type pH Dry Wet IB______________________________________Commercial PK-MKL 11 4.8 0 -- 9.5 16.1 8.6 0.28 3.0 23.5 11.4 0.30Binary PK-MKL.sup.3 10.5 25.6 13.1 0.46 5.0 27.0 16.1 0.52______________________________________ .sup.1 Waferboards pressed 5 min. at 210° C. .sup.2 Resin containing 50% PF solid by weight .sup.3 Binary PFMKL.sup.3 resin formulated from the single two stage process
EXAMPLE 3
Test results as set forth in Table 3 indicate that an NH 4 SSL-PF adhesive having acceptable adhesion characteristics is obtained where the weight ratio of high average molecular weight PF to low average molecular weight PF is between 1:1 and 4:1, with optimal results being obtained where the weight ratio is 7:3. As also indicated by the results of Table 3, the percentage yield of adhesive obtained upon spray drying is enhanced where high MW PF molecular weight PF is present in greater quantity, with acceptable results being obtained for binary PF having at least 70% high MW PF.
TABLE 3______________________________________Optimization of PF molecular weight distributionwith relation to SSL (50%) - PF (50%) adhesiveproperties.sup.1 and spray-drying yield.sup.2PF MOR SPRAY-HIGH MW LOW MW (MPa) DRYING(%) (%) MW.sup.3 DRY WET YIELD (%)______________________________________ 0 100 280 22.1 0 030 70 600 26.5 7.0 050 50 850 25.1 9.8 1370 30 1300 25.5 14.0 7680 20 1350 27.1 12.3 82100 0 1590 16.9 0 90______________________________________ .sup.1 Waferboard of 11.1 mm thickness press 4 minutes at 210° C. .sup.2 Spray dried with a laboratory spraydryer (Bowen BE 1031) at 165° C. inlet and 90° outlet temperature. .sup.3 Molecular weight determined by size exclusion chromatography (SEC) relative to poly (ethylene glycol) standards.
EXAMPLE 4
In this example, a quick curing adhesive consisting by weight of 15% lignin of various origin and 85% binary PF resin (comprised of a 1:1 by weight mixture of high and low average molecular weight PF) was prepared. As indicated by the test results as summarized in Table 4, the binary PF resin effectively cross-linked each of the various lignin copolymers identified in Table 4 to produce an adhesive having adhesion characteristics comparable to a commercial PF adhesive.
TABLE 4______________________________________Effect of lignin type on binary PF (85%) - lignin (15%)adhesive properties for homogeneous waferboards.sup.1 MORRESIN RESIN PRESS MPaTYPE pH CYCLE DRY WET______________________________________Kraft Lignin 10.3 3 28.0 13.7Steam Hydrolyzed 9.5.sup.2 3 29.5 14.7LigninNH.sub.4 SSL 8.5 4 28.9 14.2NaSSL 9.0 4 26.2 13.6Commercial PF 3 28.8 14.8______________________________________ .sup.1 Panel 11.1 mm thickness press 3 minutes at 210° C. with 2.0 resin. .sup.2 LigninPF resin heated 2 hours at 50° C. prior to spray drying.
EXAMPLE 5
A further advantage of utilizing a binary PF resin to cross-link a lignin copolymer such as NH 4 SSL is that enhanced yields may be obtained upon spray drying. As graphically illustrated in FIG. 1, the yield on spray drying an NH 4 SSL-binary PF dispersion was greatest for a dispersion consisting of 50% by weight NH 4 SSL and 50% by weight binary PF. This is important as it indicates that more kilogram per hour of a lignin-phenolic resin can be produced in a commercial spray dryer, in comparison to spray drying of PF without lignin. This represents a higher production rate and important saving for a resin powder producer.
The following examples illustrate the properties of pre-cure resistant adhesives obtained from a mixture of a PF, a lignin and an ammonium salt. The PF may be a surface phenolic resin or a faster curing core phenolic resin. The core phenolic resin produces a faster curing pre-cure resistant PF-lignin adhesive.
EXAMPLE 6
In a mill, a waferboard mat may rest on a caul plate at 140°-150° C. for a few minutes before being transferred into the press. In the press, the mat may then rest on the hot press platen few seconds before press closing to target panel thickness. If the resin is not pre-cure resistant and cures prematurely, a poor bond will result. One method to differentiate between a face and core resin is the stroke cure test. The test involved placing 0.75 g of resin on a hot platen set at a temperature of 150° and spread back and forth until hardened and cannot be spread further. A fast core resin will generally have a short stroke cure of 15-25 seconds, which compares to 35-45 seconds for a face pre-cure resistant adhesive.
As shown in Table 5, a resin made from NH 4 SSL (30%) and PF (70%) had a stroke cure test of 42 seconds, if ammonium sulphate salt was added, longer stroke cure test could be obtained. It was also possible to obtain a resin with stroke cure test comparable to a commercial face resin (35-45 seconds) from kraft lignin (27%), (NH 4 ) 2 SO 4 (3%) and a commercial PF (70%). Similar results were also obtained with lignin other than kraft or NH 4 SSL, such as NaSSL or organosolv lignin.
TABLE 5______________________________________Effect of lignin and ammonium sulphate additives onstroke cure test of commercial core phenolic resinpowder (sprayed at 200° C. inlet and 90° C. outlet) RESIN POWDER COMPOSITION Stroke CurePF.sub.a.sup.1PF.sub.b.sup.1 Kraft.sup.2 NH.sub.4 SSL (NH.sub.4).sub.2 SO.sub.4 Test at 150° C.(%) (%) (%) (%) (%) (sec.)______________________________________100 0 0 0 0 24 0 100 0 0 0 2670 0 0 30 0 4267 0 0 30 3 62 0 67 0 30 3 3870 0 30 0 0 2270 27 0 0 3 4094 0 0 0 6 36______________________________________ .sup.1 PF.sub.a and PF.sub.b are core PF resin .sup.2 Kraft lignin precipitated and washed to remove the free inorganic salts
EXAMPLE 7
In other methods to test the resistance of an adhesive to "pre-cure", the caul plate was heated in an oven at 200° C. and then placed on the waferboard mat (wafers blended with the adhesive being tested) for five minutes under 25 kg weight. The mat was then pressed in a normal manner. The panels were then tested for internal bond strength (IB). For the pre-cure resistant adhesives, it was found the hot caul plate treatment had no adverse effects on IB. The temperature of the 1.6 mm thick metal caul plate at exit from the oven was observed to be 190° C. At contact with the wood furnish, the caul plate cooled off gradually to approximately 80° C. within the 5 minute treatment.
The results set forth in Table 6 below are for waferboard with the mat treated with a hot caul plate prior to pressing. The hot caul plate treatment had an adverse effect on IB and face failure for the sample bonded with the commercial core PF and also the binary PF copolymer. No adverse effect was noticed for the panels bonded with NH 4 SSL-PF and kraft-PF-(NH 4 ) 2 SO 4 resins as IB and face failure test results were similar to those obtained with panels bonded with the commercial face PF control.
TABLE 6______________________________________Effect of caul plate heat treatment of mats.sup.1prior to pressing on mechanical propertiesof three layer waferboards.sup.2 bondedwith commercial and experimental resins Face.sup.3 Density IB FailureFace Resin.sup.4 (kg/m.sup.3) (MPa) (%)______________________________________Commercial Face PF 675 .467 8PF.sup.5 Crosslinker 664 .390 42NH.sub.4 SSL (30%) - PF.sup.5 (70%) 652 .450 8Kraft (27%) - PF.sup.5 (70%) - 650 .509 8(NH.sub.4).sub.2 SO.sub.4 (3%)Commercial Core PF 648 .179 100______________________________________ .sup.1 Caul plate heated in an oven at 200° C. then placed on top of waferboard mat 5 minutes under 55 kg weight .sup.2 Panel pressed 4 minutes at 220° C. with 2.0% resin .sup.3 Sample delamination (failure at surface layers during testing of 1 IB samples .sup.4 The core wafers were bonded with a commercial core PF for all the panels .sup.5 Experimental resin composed of high MW PF (70%) and low MW PF (30% resins | Fast cure and "pre-cure" resistance thermosetting adhesives and methods for their production useful for binding lignocellulosic materials together, are disclosed.
A fast curing adhesive is obtained by cross-linking binary phenol-formaldehyde consisting of high average molecular weight phenolformaldehyde (PF) resin and low average molecular weight PF resin with lignin. A "pre-cure" resistant adhesive is obtained by cross-linking a PF resin, such as binary phenol-formaldehyde, with a lignin with the addition of ammonia preferably in the form of an ammonium salt. The lignin may be obtained from different wood pulping waste materials including that recovered from the sulphite, kraft, organosolv or steam hydrolysed wood pulping processes. The adhesive can be produced as an aqueous solution of dispersion, and used in either a basic or acidic environment. The quick setting and "pre-cure" resistant adhesive are inexpensive to produce and both display improved adhesion characteristics when compared with existing adhesives prepared from wood waste products. The adhesives also compare advantageously to a variety of existing commercial phenolic resin presently being used in the manufacture of wood composite products such as waferboards. These adhesives are capable of being spray dried more easily and produce higher yields, when compared with existing wood waste products which have been cross-linked with commercial PF resin or to a variety of existing commercial phenolic resins. | 2 |
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] The present application claims the benefit of Provisional Patent Application Ser. No. 60/737,569, filed Nov. 17, 2005, the entire disclosure of which is incorporated herein by reference in its entirety.
BACKGROUND OF THE INVENTION
[0002] The need to be able to effectively see a target and aim a weapon in the direction of the target is well recognized. Tactical illuminators to facilitate illuminating a target and aiming a weapon, especially under low light conditions, are known. Tactical illuminators typically have an incandescent lamp or light emitting diode (LED) to provide general illumination of an area or person of interest. The output is typically a white light capable of projecting 40 to 150 lumens, although higher output lights are also known. Some tactical illuminators have a laser for providing point of impact indication.
[0003] The tactical illuminator may be attached to a weapon, for example a handgun, long gun, or shotgun, in a variety of different ways. Some tactical illuminators are secured to a handgun having a set of rails located under the barrel, in an area forward of the trigger guard, and some tactical illuminators are secured to the trigger guard.
[0004] These tactical illuminators typically have one or more actuators to turn the light and/or laser on or off located on the ends of these devices. Some tactical illuminators for use with handguns have actuators that straddle the trigger guard to allow the operator to control the light from either side of the weapon. These actuators are not independent. Actuating one actuator on one side of the trigger guard causes the other actuator on the other side of the trigger guard to also move. In some tactical illuminators, rotating the actuator on the right side of the trigger guard upward (about a horizontal axis) causes the actuator on the left side of the trigger guard to also rotate upward. In other tactical illuminators, rotating the actuator on the right side of the trigger guard counterclockwise (about a longitudinal axis) causes the actuator on the left side of the trigger guard to also rotate counterclockwise. Placement of fingers on the trigger or non-trigger hand can impede movement of the actuator on an opposite side of the gun.
BRIEF DESCRIPTION OF THE DRAWINGS
[0005] Features and advantages of the present invention are set forth by description of embodiments consistent therewith, which description should be considered along with the accompanying drawings, wherein:
[0006] FIG. 1 is a perspective view of a tactical illuminator consistent with one embodiment of the invention mounted to a weapon.
[0007] FIG. 2 is a rear perspective view of the tactical illuminator of FIG. 1 .
[0008] FIG. 3 is an exploded perspective view of a tail cap assembly of the tactical illuminator of FIG. 1 .
[0009] FIG. 4 is a rear view of a tap cap assembly consistent with a second embodiment of the invention.
DETAILED DESCRIPTION OF THE EMBODIMENTS
[0010] With reference to FIGS. 1 and 2 , there is depicted a tactical illuminator 100 consistent with one embodiment of the invention mountable to a weapon 200 . For convenience, the description that follows describes the tactical illuminator as a device generally used to cast light upon a target area or a portion thereof. The light may extend outwardly from a first end of the tactical illuminator 100 from a light emitter 170 and be generally aligned parallel with a longitudinal axis LA of the weapon 200 . The light may illuminate a large area (e.g. a flashlight) or may be concentrated on a small area (e.g. laser pointer).
[0011] The weapon 200 may be a handgun (as shown), a long gun, or shotgun. A set of rails 202 may be disposed in an area forward of a trigger guard 204 extending generally parallel to the longitudinal axis LA of the weapon 200 . The tactical illuminator 100 may be coupled to rails 202 in a variety of different ways. For example, the tactical illuminator may utilize the spring-biased mechanism disclosed in issued U.S. Pat. No. 6, 574,901, or a conventional rail or trigger guard clamping mechanism.
[0012] One or more actuators for controlling the on/off status of the light emitter 170 may extend outwardly from a second end of the tactical illuminator 100 . A first actuator 106 A may be spaced from a second actuator 106 B (see FIG. 3 ) by a distance sufficient to allow the trigger guard 204 to extend therebetween. The actuators may be part of a tail cap assembly 104 that may be coupled to the housing 102 with a retainer 144 . The retainer 144 may be secured to bosses 142 in the tail cap assembly 104 by a retainer pin 140 that may be rotatable about an axis perpendicular to the longitudinal axis of the housing 102 . Alternatively, a retainer may be secured to the housing by a retainer pin.
[0013] FIG. 3 is an exploded perspective view of a tail cap assembly consistent with one embodiment of the invention. A first housing portion 120 and a second housing portion 122 may be coupled together with a gasket 124 and O rings 150 to form a water-tight tail cap assembly 104 . First actuator 106 A and second actuator 106 B may be pivotably coupled to the first housing portion 120 by fasteners 126 extending through openings 128 in the first and second actuators 106 A, 106 B and openings 130 in the first housing portion 120 . The first housing portion 120 may have protrusions 134 that extend through openings 132 in the first and second actuators 106 A, 106 B to limit the travel of the first and second actuators 106 A, 106 B.
[0014] First and second actuators 106 A, 106 B may be coupled to cam members 152 to urge portions 154 A of conductors 154 into electrical contact with portions 156 A of electrical conductor 156 . The cam members 152 may have cammed surfaces on opposing sides to provide momentary and constant-on operation and provide tactile feel to actuators 106 A, 106 B. The end portion 156 B of electrical conductor 156 may extend through an opening 162 in second housing portion 122 to provide an electrical connection to a first battery 164 disposed in the housing 102 . Electrical conductor 158 may provide an electrical connection between conductors 154 and contact 160 , which in turn provide an electrical connection to a second battery 166 disposed in the housing 102 .
[0015] FIG. 4 is a rear view of a tap cap assembly 104 ′ consistent with a second embodiment of the invention. The rear tail cap assembly 104 ′ may have protrusions 136 for limiting travel of the first and second actuators 106 A, 106 B.
[0016] It has been discovered that it is easier to train a peace officer if a tactical illuminator actuator(s) works the same, regardless of which hand the weapon is in. FIGS. 3 and 4 show that the first actuator 106 A may be moveable in a first general direction D 1 (upward, when the weapon is operated in its typical orientation, i.e. the trigger guard under the barrel) to cause the light emitter to turn on and stay on and moveable in a second general direction D 2 (downward) to cause the light emitter to stay on as long as the actuator is actuated and turn off when released. Second actuator 106 B may be moveable in the first general direction D 1 to cause the light emitter to turn on and stay on and moveable in the second general direction D 2 to cause the light emitter to turn on as long as the actuator is actuated and turn off when released. Clockwise rotation of the first actuator 106 A may cause the light emitter 170 to turn on and stay on and counterclockwise rotation may cause the light emitter 170 to turn on as long as the actuator 106 A is actuated. Counterclockwise rotation of the second actuator 106 B may cause the light emitter 170 to turn on and stay on and clockwise rotation may cause the light emitter 170 to stay on as long as the actuator 106 B is actuated. The correlation between the clockwise/counterclockwise movement of the actuators 106 A, 106 B and whether the light emitter 170 turns on and stays on may be changed without departing from the invention.
[0017] According to one aspect there is provided an illuminator for use with a weapon having a trigger guard. The illuminator may include a housing having a longitudinal axis, the housing at least partially enclosing a battery and supporting a first and a second movable actuator mechanically coupled to the housing. The first actuator moveable in a first general direction, independent of the second actuator, to cause a light emitter coupleable to the battery to turn on and stay on and moveable in a second general direction, independent of the second actuator, to cause the light emitter to turn on as long as the actuator is actuated, and the second actuator moveable in the first general direction, independent of the first actuator, to cause the light emitter to turn on and stay on and moveable in the second general direction, independent of the first actuator, to cause the light emitter to stay on as long as the actuator is actuated.
[0018] According to another aspect there is provided a tactical illuminator for use with a weapon having a trigger guard. The tactical illuminator may include a housing for at least partially enclosing a battery and supporting a first actuator rotatable about a first axis parallel to a longitudinal axis of the housing and a second actuator rotatable about a second axis parallel to the longitudinal axis of the housing. The first and second actuators configured to selectively control an on/off status of a light emitter coupleable to the battery. The first actuator actuatable from a first side of the trigger guard and the second actuator actuatable from a second side of the trigger guard, the second actuator being operable independent of the first actuator.
[0019] According to a yet another aspect there is provided a method of controlling a light emitter in a tactical flashlight. The method may include the steps of rotating a first actuator about a first axis parallel with a longitudinal axis of the tactical flashlight in a first general direction to cause the light emitter to turn on and stay on and rotating the first actuator about the first axis in a second general direction to cause the light emitter to turn on as long as the actuator is actuated. The method may further include the steps of rotating a second actuator about a second axis spaced from the first axis and parallel with the longitudinal axis in the first general direction to cause the light emitter to turn on and stay on and rotating the second actuator about the second axis in the second general direction to cause the light emitter to turn on as long as the actuator is actuated.
[0020] Although several embodiments of the present invention have been described in detail herein, the invention is not limited hereto. It will be appreciated by those having ordinary skill in the art that various modifications can be made without materially departing from the novel and advantageous teachings of the invention. Accordingly, the embodiments disclosed herein are by way of example. It is to be understood that the cope of the invention is not limited thereby | A plurality of actuators allow a gun operator to control the on/off status of an illuminator attached to a weapon in the area forward of the trigger guard. The actuators are spaced to allow them to extend rearwardly on opposite sides of the trigger guard. “Up” turns the light emitter on and keeps it on or allows it to turn on as long as the actuator is actuated, regardless of which side of the trigger guard the actuators is actuated. | 5 |
BACKGROUND OF THE INVENTION
[0001] The present invention generally relates to sidewall panel systems for aircraft cabins and, more particularly, to a sidewall panel having reconfigurable inserts allowing the panel to be placed anywhere along the cabin wall.
[0002] Present-day commercial aircraft cabins typically have various layouts depending upon the use to which the aircraft is being put. These layouts are made up of such items as seating for personnel, overhead bins for storage of personal items, sidewall panels covering the interior walls of the cabin, and monuments (i.e., closets, restrooms, interior dividers, and other space-defining items). The sidewall panels may have panel openings that oppose structural windows in the outer wall of the fuselage, so that passengers can see out of the aircraft. When there is a structural window in the outboard wall of the aircraft, a sidewall panel opening is aligned with the structural window and an inner window assembly is inserted through the sidewall panel to mate with the structural window. The sidewall panels must be configured to match different layouts with structural windows having different spacing arrangements. Aircraft designers desire consequently to minimize the number of different types of sidewall panels with respect to the panel openings required to accommodate these various layouts and structural window arrangements.
[0003] Therefore, efforts have been made to standardize the configuration of the sidewall panels so as to reduce panel inventory and tooling costs. Typically, a sidewall panel may have a given width when accommodating a single opening and a double width when accommodating two openings. For single width panels, there may be two more types, one with an opening and one without an opening. For double width panels, there may be four types, i.e. an opening on the left, an opening on the right, openings on both sides, and no openings. This is necessary since monument placement within the layout generally requires a standardized profile along the sidewall panel so that the monument may conform to the panel as needed. As can be readily seen, as the number of sidewall panel types that have sufficient width to accommodate three or more openings increases, the number of panel/window opening permutations increases geometrically. This in turn increases the different distinguishable sidewall panel types that must be fabricated. Each separate panel type requires different tooling, which in turn increases expense. Furthermore, in certain places in the airplane, non-standard frame spacings may require different width sidewalls, which further multiplies the number of different sidewall configurations and external window arrangements.
[0004] When an aircraft operator reconfigures the cabin interior, e.g. adding or reducing seats in different seating classes, the monuments for that layout may also have to be moved, which may result in covering or uncovering window openings. This may require different sidewall types to be installed. Therefore, the aircraft owner must also stock multiple spare sidewall configurations to cover each of the sidewall variants.
[0005] Sculpturing around the window opening complicates the reconfiguration process. On some aircraft models, the sidewall profile is different along its length due to sculpturing around the windows, and therefore simply blanking out a window hole would still result in a unique interface between the monument and the sidewall to fill the gap between the outboard monument profile and the inboard sidewall profile.
[0006] More specifically, prior art sidewall panels must have multiple configurations and types, so that different cabin layouts and window arrangements may be accommodated. Prior art sidewall panels also provide sculpturing of the sidewall panel adjacent to the panel opening to provide more room for passengers. Such sidewall panels typically span a space between three frames, or ribs, of a fuselage primary structure with an external structural window interposed between each frame, and thus are said to cover two frame bays. Additionally, some single frame bay sidewalls may also be used to interface with monuments and doorways or when there is an odd number of frame bays between the ends of the sidewall. Multiple sidewall configurations are thus required in the prior art to support monument locations. Typical configurations required are as follows:
Two frame bay panel, left and right sides with window openings Two frame bay panel, left with window opening and right without window opening Two frame bay panel, left without window opening and right with window opening Two frame bay panel, no window openings One frame bay panel with window One frame bay panel without window
Thus, six separate and distinct sidewall types must be constructed and stocked in order to support different cabin layouts, according to the prior art.
[0013] FIGS. 1A and 1B illustrate a typical situation that is frequently encountered when reconfiguring aircraft cabins. Referring to FIG. 1A , three sidewall panels 120 a , 120 b , 120 c are shown, each sidewall panel being of a different type. A closet monument 140 is shown between the first seat row 110 a and the second seat row 110 b . Since the closet monument 140 overlaps sidewall panels 120 a and 120 b , then sidewall panel 120 a is of a type having a left side with a window opening and a right side without a window opening, and sidewall panel 120 b is of a type having a left side without a window opening and a right side with a window opening; sidewall panel 120 c is of a type having openings on both sides. Because of window sculpturing, the prior art solution for this particular configuration change has been to provide these three panel types. If it is desired to move the closet monument 140 from a location indicated in FIG. 1A to a location indicated in FIG. 1B , then seat rows 110 b and 110 c must be moved forward and the closet monument 140 must be moved aft; in order to cover window openings 130 b and 130 c , all three sidewall panels 120 a , 120 b , and 120 c , must be removed and relocated to a different position along the sidewall; this would require the additional removal of seat rows 110 a and 110 d in order to access all the sidewall panels 120 a - 120 c.
[0014] A typical sidewall panel 200 is shown according to the prior art. According to FIG. 2A , a vertical cross-sectional view of the sidewall panel 200 may be seen. The sidewall panel 200 may have a panel opening 210 into which is inserted a window assembly 240 . The sculpturing area 230 immediately around the panel opening 210 may be curved in an outboard direction, indicated by the arrow labeled 288 . This outboard curvature may provide additional room to a passenger seated adjacent to the sidewall panel 200 , as indicated by the direction of the arrow labeled 299 . A flange 250 along around the perimeter of the window assembly 240 may abut the inboard surface 202 of the sidewall panel 200 to hold the window reveal 240 in place within the panel opening 210 . As can be readily seen, the replacement of the window assembly 240 by a cover plate to fill the panel opening will not affect the sculpturing around the panel opening. Furthermore, the gradual slope of the sculpturing area 230 as it conforms to the inboard surface 202 may be so gradual so that it is difficult to provide an adequate locking mechanism for a cover or to provide a cover having sufficient thickness around its perimeter to smoothly blend to the inboard surface 202 .
[0015] The prior art contains a number of examples of how the sidewall panel configuration has been addressed. U.S. Pat. No. 6,082,674 discloses a sidewall panel in which the sculpturing around the inner window is contained in the sidewall so that the inner window, comprising a dust cover and window shade, may be affixed to the outboard side of the sidewall panel. There is no suggestion of using a window reveal to interface the inner window assembly to the sidewall panel, and presumably the opening perimeter of the sidewall panel functions as a window reveal. European Pat. App. No. EP 1306302 A2 discloses a sidewall panel having a snap-in window assembly, in which the sculpturing around the panel opening is shown to be a portion of the sidewall panel. An inner window assembly includes a window reveal that attaches to the opening using snap-in fasteners.
[0016] As can be seen, there is a need for reducing the number of sidewall panel configurations by providing modular and interchangeable components to the sidewall system so that the numbers of different types of sidewall panels may be reduced and standardized.
SUMMARY OF THE INVENTION
[0017] The present invention provides simply curved sidewall panels (curved vertically around the fuselage but horizontally linear along the length of the airplane) to provide a consistent profile for monument placement. Embodiments of the present invention add features to the outboard side of the sidewall so that a flush mounted cover plate can fill a panel opening when a window is not needed. An inner window assembly may be provided that includes any required sculpturing in the window reveal, thus moving sculpturing from the sidewall panel to the window reveal and allowing more uniformity in the different types of sidewall panel profiles. Thus, a single sidewall panel may be used for multiple window configurations. The configuration of the sidewall panel may be rapidly changed to add or remove windows when interior layout changes occur. This results in the production of fewer parts as well as facilitating faster and less expensive interior reconfigurations. In a case where unique frame spacings exist, only one new tool may be required for the different frame spacing rather than four tools to cover each possible window arrangement.
[0018] In one aspect of the present invention, an interior sidewall panel for a cabin area of an aircraft is provided, where the panel comprises a surface with a curved aspect along a vertical axis to conform to an interior side of an aircraft frame and with a linear aspect along a longitudinal axis; and a panel opening in the surface, the panel opening having a recessed lip around its perimeter.
[0019] In another aspect of the present invention, a sidewall panel cover plate is provided for filling a panel opening of an aircraft sidewall having a constant curvature, where the cover plate comprises a surface having a profile the same as the aircraft sidewall and a fastener.
[0020] In still another aspect of the present invention, a window assembly is provided for an aircraft sidewall panel having a constant curvature, the sidewall panel having a panel opening and an inboard surface, where the window assembly comprises a window reveal providing sculpturing around the panel opening, the window reveal having a flange extending about its periphery for making abutting contact with the inboard surface when the window assembly is inserted through the panel opening from the inboard side of the sidewall panel, the flange preventing further outboard excursion of the window assembly.
[0021] In yet another aspect of the present invention, a configurable sidewall assembly is provided, the sidewall assembly comprising a sidewall panel with an inboard surface and an outboard surface, the sidewall panel with a curvature conforming the outboard surface to an aircraft frame, the sidewall panel having a panel opening; a window reveal sized for insertion into the panel opening; and a cover plate sized for insertion into the panel opening when the reveal is not occupying the opening, wherein the cover plate and the window reveal are selectively inserted into the opening.
[0022] In yet another aspect of the present invention, an interior sidewall system is provided for a layout of a cabin area in an aircraft, the system comprising a plurality of sidewall panels, each panel curved vertically to conform to an interior side of an aircraft frame and horizontally linear, each panel with at least one opening with all openings having an identical shape; a plurality of cover plates shaped for insertion in an opening; and a plurality of window assemblies shaped for insertion in a selected opening, each window assembly having a window reveal configured with sculpturing, the window reveal with a flange for abutting contact with the inboard surface of a selected panel and held in releasable attachment thereto by a snap-fit fastener that is released from the inboard side of the selected panel, wherein each opening is selectively provided with a cover plate or a window assembly selected according to the layout.
[0023] In a further aspect of the present invention, a method is provided for enclosing an interior wall of an aircraft cabin, where the method comprises the following steps: fabricating a sidewall panel that is longitudinally straight and vertically curved, with the sidewall panel having at least one opening; fabricating an inner window assembly with a window reveal that has sculpturing extending outboard of the sidewall panel, with the window assembly sized for removable insertion into a selected opening; shaping a cover plate for removable insertion into a selected opening; installing a plurality of sidewall panels along the interior wall according to an arrangement of monuments and seats within the aircraft cabin; and, for each opening in the plurality of sidewall panels, selecting either a cover plate or a window reveal for insertion into the opening according to the arrangement.
[0024] These and other features, aspects and advantages of the present invention will become better understood with reference to the following drawings, description and claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0025] FIG. 1A is an interior elevation view of a typical aircraft cabin showing a layout having seating and a closet monument, according to the prior art;
[0026] FIG. 1B is an interior elevation view of the same aircraft cabin as shown in FIG. 1A , but with the closet monument and one row of seating moved to a different location to illustrate the corresponding change required for the adjacent sidewall panels, according to the prior art;
[0027] FIG. 2A is a cross sectional view taken along a vertical line of a prior art sidewall panel showing the presence of sculpturing within the sidewall panel around the panel opening, according to the prior art;
[0028] FIG. 2B is a cross sectional view taken along a horizontal line of a prior art sidewall panel showing the presence of sculpturing within the sidewall panel around the panel opening, according to the prior art;
[0029] FIG. 3A is an interior elevation view of a typical aircraft cabin showing a layout having seating and a closet monument, according to an embodiment of the invention;
[0030] FIG. 3B is an interior elevation view of the same aircraft cabin as shown in FIG. 3A , but with the closet monument and one row of seating moved to a different location to illustrate the corresponding change required for the adjacent sidewall panels, according to an embodiment of the invention;
[0031] FIG. 4A is a cross sectional view taken along a vertical line of a sidewall panel where the sculpturing has been accomplished within the window assembly inserted in the panel opening, according to an embodiment of the present invention;
[0032] FIG. 4B is a cross sectional view taken along a horizontal line of a sidewall panel where the sculpturing has been accomplished within the window assemblies inserted through the panel openings, according to an embodiment of the present invention.
[0033] FIG. 5 is cross sectional view taken along a horizontal line of a window assembly to illustrate the manner in which it may be attached to a sidewall panel, according to an embodiment of the invention;
[0034] FIG. 6 is a cross sectional view taken along a horizontal line of a cover plate to illustrate the manner in which it may be attached to and made flush with the sidewall panel surface, according to an embodiment of the invention;
[0035] FIG. 7 is a cross sectional view taken along a horizontal line of a cover plate attached to the panel opening through use of a snap-fit fastener, according to an embodiment of the invention; and
[0036] FIG. 8 is a flowchart showing a method of enclosing the interior of an aircraft cabin, according to an embodiment of the invention.
DETAILED DESCRIPTION OF THE INVENTION
[0037] The following detailed description is of the best currently contemplated modes of carrying out the invention. The description is not to be taken in a limiting sense, but is made merely for the purpose of illustrating the general principles of the invention, since the scope of the invention is best defined by the appended claims.
[0038] For ease of understanding the orientation in the drawings, the terms “inside”, “inboard”, and “interior” shall refer to a direction oriented from the viewpoint of a person standing within the cabin of the aircraft, and the terms “outside”, “outboard”, and “exterior” shall refer to a direction oriented from the viewpoint of a person outside of the cabin observing the aircraft. Thus, a sidewall panel will have an interior side and an exterior side, where the interior side is that surface of the installed panel as seen by a person within the cabin of the aircraft and the exterior side is that surface of the installed panel that is seen by a person outside of the cabin of the aircraft. Other such descriptions will be obvious from the context. Similarly, the terms “aft” and “forward” are directional terms that indicate a direction away from the aircraft cockpit and towards the aircraft cockpit, respectively.
[0039] Broadly, an embodiment of the present invention provides a sidewall panel system for installation along an interior wall of an aircraft cabin. Each sidewall panel may have standard openings to accommodate inner window assemblies, but may be independent of the layout of the cabin interior. A flush-mounted cover plate may be provided by the system to fill panel openings in the sidewall panel when windows are not required. The outboard side of the sidewall panel may allow the cover plate to be snap-fit onto sidewall panel when the interior window structure has been removed. Furthermore, window sculpturing around the window opening may be removed from the profile of the sidewall panel and instead incorporated into the reveal of the window assembly, so that the cover plate may be flush to the panel surface when windows are not required. The present invention may be employed in aircraft cabins of commercial aircraft to enable the interior to be more easily reconfigured by the aircraft manufacturer according to the requirements of the customer to accommodate variable positioning of monuments within the cabin interior.
[0040] Window sculpturing has been incorporated as part of the sidewall panel in the prior art. The present invention moves the sculpturing to the window reveal of the inner window assembly, thus allowing simpler tooling to be used to fabricate the sidewall panel. This inventive configuration also allows interchangeable inserts to be used in the panel opening, i.e., either a window assembly (with reveal) or a blank cover plate, so that the sidewall panel can be reconfigured without complete removal and replacement of the entire sidewall panel, as is done in the prior art. This in turn allows sidewall panels to be reconfigured for monument placement in less time and with less expense than is required by the prior art.
[0041] An embodiment of the invention disclosed herein includes window sculpturing within the reveal of the window assembly that is inserted into the window opening, so that the number of distinct sidewall panel types may be reduced to one or two. By eliminating window sculpturing in the sidewall, the sidewall panels that may be provided by the embodiment may have a constant linear profile longitudinally along the airplane length (station.) This in turn may allow a standardized cover plate to be used to fill the window opening when not in use. These cover plates may be flush with the panel surface since sculpturing is not present on the panel, so that a standardized surface profile may be made available for the placement of monuments against the sidewall surface. The cover plates may be furnished with snap-fit fasteners that allow the cover plates to snap in and out of the panel openings. The window assembly may be similarly furnished with snap-fit fasteners similar to those of the cover plates. These snap-fit fasteners may be integral to the item, unlike the prior art, in order to permit these inserts to be attached without requiring special tools and to eliminate the requirement for separate fasteners to secure the inserts within the panel openings.
[0042] The advantages of such an arrangement may be seen in FIGS. 3A and 3B , which depict the same layout reconfiguration as shown in FIGS. 1A and 1B . If the sidewall panels and cover plates of the current invention were configured along the sidewall, only a sidewall panel 120 c of a type having window openings 135 a - 135 f in both sides would be required. The movement of the closet monument 140 would not require the removal and reinstallation of any sidewalls, but merely the removal of the cover plates 150 a and 150 b in window openings 135 b and 135 c , respectively, and reinstallation of the cover plates 150 a and 150 b into window openings 135 d and 135 e ; seat rows 110 a - 110 d would only be moved as required for the relocation of closet monument 140 and not for removal and reinstallation of any sidewall panel 120 c . This procedure would obviously require less time and therefore less expense than heretofore.
[0043] For purposes of this disclosure, a snap-fit fastener may be considered to be a mechanical joint system where the part-to-part attachment is accomplished with locating and locking features (i.e. constraint features) that are homogeneous with or integral to one or the other of the components being joined. Such joining may require the (flexible) locking features to move aside for engagement with the mating part, followed by a return of the locking feature toward its original position to accomplish the interference required to fasten the components together. Locator features, the second type of constraint feature, are inflexible, providing strength and stability to the attachment. Although any of the three types of snap-fit fastenings, i.e. annular, cantilever, and torsional, may be used with the components described herein, the cantilever type may be used and described in the embodiments described herein without limiting the scope of the disclosure.
[0044] Referring now to FIGS. 4A and 4B , a sidewall panel 400 is shown according to an embodiment of the invention. The window assembly 440 may have lengthened sides to provide a sculpturing area 430 as a portion of the window assembly 440 instead as a portion of the sidewall panel 400 . The profile of the sidewall panel 400 may be a smooth curve along its vertical cross section, as shown in FIG. 4A , so that the horizontal (longitudinal) cross section as shown in FIG. 4B may be linear. Geometrically, this means that all points on the surface of the sidewall panel 400 that fall upon a horizontal plane drawn through any portion of the sidewall panel 400 may fall along a straight line. This in effect eliminates any sculpturing from the sidewall panel ( 400 ) so that it may be included in the window assembly 440 . The sculpturing around the panel opening 410 may be incorporated in the sculpturing area 430 of the window assembly 440 to allow a simple cover plate to be used to fill the panel opening 410 when the window assembly 440 is not required. Note that when passengers press against the window assembly 440 , the sidewall panel 400 immediately behind the flange 450 of the window reveal perimeter may support such outboard loading.
[0045] Referring to FIG. 5 , a more detailed view of the window reveal shown in FIG. 4B may be seen. The window assembly 440 may be attached to the sidewall panel 400 by a flange 450 surrounding its perimeter, so that the flange 450 may make abutting contact with the inboard surface 402 of the sidewall panel 400 . The window reveal of the window assembly 440 may support the flange that may snap into the panel opening 410 and held by a snap-fit fastener. In FIG. 6 , a cover plate 460 may be seen inserted into the same panel opening 410 as the window assembly 440 . The cover plate 460 may have an outwardly extending lip 418 sized for mating contact with the recessed lip 415 surrounding the panel opening 410 , so that the surface of the cover plate 460 may be contiguous and flush with the inboard surface 402 . The cover plate 460 may be held in place by snap-fit fasteners as will be presently seen. By creating inserts, i.e. the window assembly 440 and the cover plate 460 , that snap into the same panel opening 410 , the same sidewall panels 400 may be used for any combination of windows and for any monument location required by the layout, since the inboard profile of the sidewall panels are the same throughout.
[0046] Referring to FIG. 7 , a snap-fit latching mechanism may be seen according to an embodiment of the invention. One or more snap-fit fasteners 470 may be fabricated as part of the cover plate 460 . Each snap-fit fastener 470 may be of a cantilever type that may be integral to the cover plate 460 along its perimeter. Each snap-fit fastener 470 may be configured so that it moves inwardly as the cover plate 460 is inserted into the panel opening 410 and then snaps back to engage against the outboard side 404 of the sidewall panel 400 . The snap-fit fasteners 470 may be disengaged from the outboard side of the sidewall panel 400 when the sidewall panel 400 is removed from its installed position; alternatively, features may be added to disengage the snap-fit fasteners from the inboard side of the sidewall panel 400 by using small tool holes (not shown) that are well known in the art.. Either method may for safety purposes prevent passengers removing the inserts.
[0047] Referring now to FIG. 8 , a flowchart of a method for enclosing an interior wall of an aircraft cabin is shown. A sidewall panel 400 is provided according to the block labeled 810 , where the sidewall panel 400 may have one or more sidewall panel openings 410 . The sidewall panel 400 may lack any sculpturing around its panel opening 410 , so that the cross section of the sidewall panel 400 is longitudinally linear but vertically curved to conform to the interior side of the aircraft frame. One or more window assemblies 440 may also be provided according to the block labeled 820 , each window assembly 440 having the desired sculpturing in the window reveal surrounding the window assembly 440 . Similarly, one or more cover plates 460 may also be provided according to the block labeled 830 , where each cover plate 460 may have the same curvature as the sidewall panel 400 so that it may be flush with the inboard surface 402 of the sidewall panel 400 . The window assemblies 440 and the cover plates 460 may be sized for insertion within the panel openings 410 . The sidewall panels 400 may be installed along the interior aircraft cabin wall, according to the block labeled 840 , without regard to the layout of the aircraft cabin. Either a window assembly 440 or a cover plate 460 may be selected according to the desired arrangement of seats and monuments within the aircraft cabin, according to the block labeled 850 . The window assemblies 440 and cover plates 460 may then be installed within their designated panel openings 410 , according to the block labeled 860 .
[0048] Thus, a reconfigurable interior sidewall system has been described, which may be easily reconfigured for different layouts within the aircraft cabin in less time than heretofore. The interior sidewall system may provide an inner window assembly in which any sculpturing around the panel opening is moved from the sidewall panel to the window reveal of the inner window assembly. It may also provide a cover panel that may be used to fill the panel opening in such a way as to provide a constant profile across all sidewall panels for placement of monuments within the aircraft cabin. It should be understood, of course, that the foregoing relates to exemplary embodiments of the invention and that modifications may be made without departing from the spirit and scope of the invention as set forth in the following claims. | A reconfigurable interior sidewall system includes one or more simply curved sidewall panels, each curved around the fuselage but longitudinally linear and providing a consistent mating surface for monuments. Panel openings are provided in each panel so that inner window assemblies may be installed for opposing structural windows, each inner window assembly having outward sculpturing for additional cabin room. A cover plate is also provided for flush insertion into the opening to fill the opening when it is not needed and to provide a constant profile for cabin monuments whenever the layout of the cabin changes. This results in the production of fewer parts as well as facilitating faster and less expensive interior reconfigurations. | 1 |
BACKGROUND
[0001] 1. Field
[0002] The disclosed and claimed concept relates generally to handheld electronic devices and, more particularly, to a key dome assembly for a handheld electronic device, wherein the dome assembly includes micro structures which elevate the dome shaped element from a supporting surface.
[0003] 2. Description of the Related Art
[0004] Numerous types of handheld electronic devices are known. Examples of such handheld electronic devices include, for instance, personal data assistants (PDAs), handheld computers, two-way pagers, cellular telephones, and the like. Many handheld electronic devices also feature a wireless communication capability, although many such handheld electronic devices are stand-alone devices that are functional without communication with other devices.
[0005] Such handheld electronic devices are generally intended to be portable, with many of such devices being small enough to fit within, for example, a pocket, a belt holster, a briefcase, or a purse. As the form factor of such devices has shrunk for improved portability, so has the size of components such as keyboards or keypads. The keyboards or keypads include keys that act as switches for input entry when actuated. In furtherance of miniaturization of keyboard assemblies such as keyboards and keypads, one general approach implemented by several different manufacturers has involved the use of an electrical key in the form of a resilient dome shaped element that is electrically conductive and is disposed on a circuit board.
[0006] In simplest form, such a dome assembly is a smooth sector of a hollow sphere. When an actuation force is applied to the apex of the dome assembly, the dome assembly collapses, completing an electrical circuit or at least an open portion of an electrical circuit of the device. The collapsing dome assembly provides a tactile feedback to the user of the handheld electronic device. Such simple sphere segments have been generally effective for their intended purpose; however they have not been without limitation, as the tactile feedback is sometimes not noticeable by the user, particularly in miniaturized keyboard assemblies.
[0007] Accordingly, it is desirable to manufacture a dome assembly which produces a detectable tactile feedback when electrical contact is made.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] A full understanding of the disclosed and claimed concept can be gained from the following Description when read in conjunction with the accompanying drawings in which:
[0009] FIG. 1 is a front elevational view of an example handheld electronic device in accordance with the disclosed and claimed concept;
[0010] FIG. 2 is a schematic depiction of the example handheld electronic device of FIG. 1 ;
[0011] FIG. 3 is a perspective view of the top of an embodiment of a dome assembly disposed on a support structure in accordance with the disclosed and claimed concept;
[0012] FIG. 4 is a perspective view of the embodiment of FIG. 3 with a section removed along line 4 - 4 to show detail;
[0013] FIG. 5 is the perspective view of FIG. 4 showing the dome assembly displaced in a second position.
[0014] FIGS. 6-8 are perspective views of alternate embodiments of a dome assembly in accordance with the disclosed and claimed concept; and
[0015] FIG. 9 is a perspective view of the embodiment of FIG. 8 with a section removed along line 9 - 9 to show detail.
[0016] FIG. 10 is a top view of an embodiment of a dome assembly in accordance with the disclosed and claimed concept.
[0017] FIG. 11 is a perspective view of a portion of a keyboard assembly in accordance with the disclosed and claimed concept.
[0018] Similar reference numerals refer to similar parts throughout the specification.
DESCRIPTION
[0019] An improved handheld electronic device 4 in accordance with the disclosed and claimed concept is indicated generally in FIG. 1 and is depicted schematically in FIG. 2 . The improved handheld electronic device 4 comprises a housing 6 , and further comprises an input apparatus 8 , an output apparatus 12 , and a processor apparatus 16 disposed on the housing 6 . The input apparatus 8 provides input to the processor apparatus 16 . The processor apparatus 16 provides output signals to the output apparatus 12 .
[0020] The input apparatus 8 comprises a keypad 20 and a track ball 24 . The keypad 20 in the example embodiment depicted herein comprises a plurality of keys 26 that are each actuatable to provide input to the processor apparatus 16 . The track ball 24 is rotatable to provide navigational and other input to the processor apparatus 16 , and additionally is translatable in a direction inwardly toward the handheld electronic device 4 to provide other input, such as selection inputs. The track ball 24 is freely rotatable on the housing 6 and thus is able to provide navigational inputs in the vertical direction, i.e., the up-down direction, in the horizontal direction, i.e., the left-right direction, as well as combinations thereof. The keys 26 and the track ball 24 serve as input members which are actuatable to provide input to the processor apparatus 16 . The example output apparatus 12 comprises a display 32 .
[0021] As shown in FIG. 1 , many of the keys 26 have a plurality of letters, i.e., linguistic elements, assigned thereto. For instance, one of the keys 26 has assigned thereto the letters “A” and “S”. Another of the keys 26 has assigned thereto the letters “Q” and “w”. The letters of the example keypad 20 are in an arrangement of a reduced QWERTY keyboard. It is to be appreciated that although the example device shown in FIG. 1 utilizes a reduced keypad 20 , the disclosed and claimed concept may readily be employed in other applications, such as but not limited to, a regular (non-reduced) keypad or other combination of one or more individual keys either integral to an electronic device or part of a separate keyboard assembly external to an electronic device.
[0022] Examples of other input members not expressly depicted herein would include, for instance, a mouse or track wheel for providing navigational inputs, such as could be reflected by movement of a cursor on the display 32 , and other inputs such as selection inputs. Still other example input members would include a touch-sensitive display, a stylus pen for making menu input selections on a touch-sensitive display displaying menu options and/or soft buttons of a graphical user interface (GUI), hard buttons disposed on the housing 6 of the handheld electronic device 4 , and so on. Examples of other output devices would include a touch-sensitive display, an audio speaker, and so on.
[0023] The processor apparatus 16 comprises a processor 36 and a memory 40 . The processor 36 may be, for example and without limitation, a microprocessor (μP) that interfaces with the memory 40 . The memory 40 can be any one or more of a variety of types of internal and/or external storage media such as, without limitation, RAM, ROM, EPROM(s), EEPROM(s), FLASH, and the like that provide a storage register, i.e., a machine readable medium, for data storage such as in the fashion of an internal storage area of a computer, and can be volatile memory or nonvolatile memory. The memory 40 has stored therein a number of routines 44 that are executable on the processor 36 . As employed herein, the expression “a number of” and variations thereof shall refer broadly to any nonzero quantity, including a quantity of one. One of the routines 44 is a disambiguation routine that is operable to disambiguate ambiguous text input, such as when one of the keys 26 having a plurality of letters assigned thereto is actuated.
[0024] Underlying each of the plurality of keys 26 is a deformable dome assembly 50 such as shown in FIGS. 3-5 . The dome assembly 50 includes a dome shaped resilient element 52 having a preferably centrally located apex 54 and extending to a periphery 56 . Preferably, resilient element 52 is formed from stainless steel coated with a conductive layer of silver plating after forming. For low end (low cost) devices, there is no post plating process on the metal dome. It is to be appreciated that resilient element 52 may also be formed from other resilient materials, such as, but not limited to, a plastic film coated with a layer of conductive carbon material.
[0025] Referring to FIGS. 3-5 , the dome assembly 50 further includes a number of elevating members 58 disposed adjacent the periphery 56 which serve to raise the periphery 56 of the resilient element 52 a distance D (see FIGS. 4 and 5 ) from a mounting surface 60 on which the dome assembly 50 is disposed. In a specific application of the present concept, the distance D which the periphery 56 of the resilient element 52 is raised above the mounting surface 60 is in the range of approximately 0.03 to 0.07 mm. However, such distance D may be of greater or lesser value depending on the application, more specifically the relative size and shape of the resilient element 52 . Although the example shown in FIGS. 3-5 shows a dome assembly 50 having eight elevating members 58 equally spaced along the periphery, it is to be appreciated that the number and spacing of such elevating members 58 may be varied.
[0026] In an application such as a handheld electronic device 4 such as shown in FIG. 1 , the mounting surface 60 may be a surface of a printed circuit board or other support formed from, or coupled to a portion of the housing 6 or other similar structure. In other example embodiments, such as, but not limited to, a keyboard or similar device separated from a main housing 6 , mounting surface 60 may be formed from a second housing or other member formed from, or coupled to a portion of the second housing. FIG. 11 shows a portion of an example keyboard assembly including a number of dome assemblies 50 .
[0027] In the example embodiment shown in FIGS. 3-5 , elevating members 58 are embossments of dimple-like shape, integrally formed from the resilient element 52 . Formation of such integral elevating members 58 may be carried out by stamping or other equivalent techniques. It is noted that although elevating members 58 shown in the example embodiment of FIGS. 3-5 are integrally formed with resilient element 52 , such members 58 could also be separately formed and then coupled to resilient element 52 . Additionally, such elevating members 58 could be coupled outside the resilient element 52 adjacent the periphery thereof while still providing the benefits of the present concept. It is to be appreciated that elevating members 58 may be of a variety of shapes including, but not limited to dimple shaped (see FIGS. 3-7 ), elongated dimple or groove (see FIGS. 8 and 9 ), cone shaped, cylindrical, or micro solid packs.
[0028] As shown in FIG. 5 , when one of the keys 26 of keypad 20 is actuated, a force F is applied preferably at or near the apex 54 of dome shaped resilient element 52 causing the dome assembly 50 to collapse from its initial relaxed position as shown in FIGS. 3-4 to a collapsed position as shown in FIG. 5 . In an application where the dome assembly 50 is disposed on a printed circuit board, the collapsed resilient element 52 , being constructed from, or coated with a conductive material will electrically engage one or more electrical contacts (not shown) disposed on the underlying printed circuit board to complete a circuit or at least a portion of a circuit. Alternatively, collapse of the resilient member 52 may cause a portion of a circuit to open. In either case, opening/closing of at least a portion of a circuit due to collapse of the resilient element 52 results in an input to the processor 36 of the handheld electronic device 4 . Upon deforming to the collapsed position, resilient element 52 produces a tactile feedback to a user of the handheld electronic device 4 thus providing the user with an indication that an input has been completed. Upon removal of the applied force F, the dome shaped resilient element 52 returns to its initial relaxed position as depicted in FIGS. 3-4 .
[0029] The addition of elevating members 58 to the resilient element 52 has been found to produce the desirable attribute of enhancing the tactile feedback to a user of the device compared to the use of a resilient element lacking such elevating members 58 in which the periphery 56 is directly disposed on a mounting surface 60 . Such improved tactile feedback can be attributed to a number of characteristics of the present concept. By elevating the periphery 56 of resilient element 52 from the mounting surface 60 , a greater travel distance (not numbered) for a depressed key 26 , and correspondingly for the apex 54 of the dome shaped resilient element 52 is provided when the resilient element 52 is moved from a non-collapsed position ( FIGS. 3-4 ) to a collapsed position ( FIG. 5 ).
[0030] The increase in travel distance of the apex 54 allows for the resilient element 52 to become more collapsed than a resilient element 52 with a periphery 56 disposed directly on a mounting surface 60 . Also, use of the elevating members 58 allows for utilization of a resilient element 52 requiring a smaller footprint than what would be required of a dome element 52 disposed directly on the mounting surface 60 if a specific key depression distance (generally equivalent to the distance traveled by the apex 54 upon collapsing of dome element 52 ) is desired.
[0031] Reduction of such footprint without decreasing the key depression distance makes the present concept readily adaptable to reduced keypad applications commonly found in handheld electronic devices. Additionally, elevation of the periphery 56 above the mounting surface 60 through the use of elevating members 58 provides improved venting of air from beneath the resilient element 52 upon collapse as well as an improved path for air to return when the resilient element 52 returns to the relaxed position. When the air beneath the dome assembly 50 does not have adequate venting for evacuation or return, such as when the periphery 56 is directly disposed on the mounting surface 60 , tactile feedback response is hindered and not as smooth as the case with the elevated periphery 56 .
[0032] Addition of elevating members 58 to the resilient element 52 has also been found to increase the area of the dome assembly 50 to which a force F may be applied to readily collapse the dome. Increase of such area is desirable by lessoning the potential negative effects of off center actuations or slight misalignments of overlying structures which would tend to not fully collapse the dome and thus not properly register an input.
[0033] Use of the elevating members 58 may also provide for reduced constraint of the periphery 56 relative to the underlying mounting surface 60 which in turn reduces the frictional forces acting against dome collapse, thus providing for a more readily collapsible dome. Such reduced constraint may occur by utilizing elevating members 58 that slightly flex outward as the resilient element 52 transitions from the non-collapsed to collapsed position. Such flexure of the elevating members 58 may result in movement of at least a portion of the periphery 56 relative to the mounting surface 60 . FIG. 10 shows a top view of a dome assembly 50 in which such elevating members 58 that slightly flex are employed. Referring to FIG. 10 , the solid line shows the position of the periphery 56 when the resilient dome element 52 is in a non-collapsed position, and the phantom line portion shows the flexed position of the periphery 56 when the resilient dome element 52 is collapsed. It is to be appreciated that the movement of the periphery 56 as well as elevating member 58 as shown in FIG. 10 has been shown for example purposes only as the amount of such potential movement would vary depending on the structure of the particular elevating members 58 and resilient element 52 .
[0034] FIGS. 6 and 7 show additional example embodiments of the present concept which demonstrate potential variations on the number of elevating members 58 utilized and also variations to the shape of the resilient element 52 . In particular, FIG. 6 shows an embodiment having half as many elevating members 58 as the example embodiment shown in FIGS. 3-5 . FIG. 7 shows an embodiment using the same number of elevating members 58 as the embodiment of FIG. 6 but instead utilizing only a portion of a resilient element 52 ′.
[0035] FIGS. 8 and 9 show a further example embodiment of the present concept in which the elevating members 58 comprise elongated dimples or grooves 58 ′ disposed on a portion of a resilient element 52 ′. Although only two such grooves of approximately equal length are shown in FIGS. 8-9 , it is to be appreciated that the quantity and size of the grooves as well as the dimensions of dome element 52 ′ can be varied according to the requirements of a specific application and still produce the desirable results of the present concept.
[0036] While specific embodiments of the disclosed and claimed concept have been described in detail, it will be appreciated by those skilled in the art that various modifications and alternatives to those details could be developed in light of the overall teachings of the disclosure. Accordingly, the particular arrangements disclosed are meant to be illustrative only and not limiting as to the scope of the disclosed and claimed concept which is to be given the full breadth of the claims appended and any and all equivalents thereof. | A dome assembly for use in a keyboard assembly of an electronic device is provided. The dome assembly includes a deflectable dome shaped element having a concave surface terminating at a periphery and a number of elevating members disposed on the element adjacent the periphery and protruding away from the concave surface. The elevating members serve to space the periphery from a mounting surface. The element is movable between an undeflected position and a deflected position. | 7 |
[0001] This nonprovisional application is a continuation of International Application No. PCT/EP2010/052776, which was filed on Mar. 4, 2010, and which claims priority to German Patent Application No. DE 10 2009 012 024.6, which was filed in Germany on Mar. 10, 2009, and which are both herein incorporated by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The invention relates to a charge air intercooler for arrangement in a suction tube.
[0004] 2. Description of the Background Art
[0005] It is known to design charge air intercoolers as indirect cooler so that the heat is dissipated by a liquid coolant. Such charge air intercoolers can be designed as an integrated unit with a suction tube of an internal combustion engine.
[0006] In this context it is known to design a floor of a charge air intercooler as a tube bundle construction and at the same time as a mounting plate for fastening at an edge of a suction tube opening.
SUMMARY OF THE INVENTION
[0007] It is therefore an object of the invention to provide a charge air intercooler for arrangement in a suction tube, which charge air intercooler is connected in a simple and reliably sealed manner to the suction tube.
[0008] Via a separate design of flange member and floor member, a better tolerance with respect to vibrations can be achieved. In addition, a higher flexibility with respect to shaping and material pairings of a suction tube and/or flange member is achieved. Depending on the details of the design, a further advantage of the invention can be that the connection between the suction tube and the flange member is not affected by potential flux residues or similar contaminants from soldering the cooler block.
[0009] In an embodiment, the floor member is made of aluminum, wherein the channels can be designed as flat tubes soldered to the floor member. In case of such an embodiment, the solution according to the invention especially relieves the connection of the flat tubes on the floor member from vibrations and mechanical stresses.
[0010] In a cost-effective and simple embodiment, the flange member can be made of a plastic. In a preferred and simple construction, a seal, such as an O-ring seal, can be provided between the floor member and the flange member. However, alternatively or additionally it is also possible that a seal is provided between the floor member and the suction tube.
[0011] In an embodiment of the invention, the flange member forms a portion of the collector, for example a collector compartment. In particular, the flange member can form a partition wall between the outside space and the charge air as well as between a coolant and the charge air or outside air. The flange member can be designed, for example, as a plastics molding, whereby it can be formed in a simple and cost-effective manner for fulfilling these functions. Preferably, it can also comprise a partition wall of the collector. Likewise, the coolant connection can be formed in a simple and cost-effective manner on the flange member, for example in the form of one-piece plastic nozzles of the same material. In a detail configuration, the floor member can have a crimping, in particular a corrugated, slotted crimping, for connecting to the flange member. Through these or other measures, a simple assembly, for example by latching of the floor member and the flange member or the collector compartment can be achieved.
[0012] In a further embodiment of the invention it is provided that the flange member can engage over the collector, wherein the flange member forms a partition wall between the charge air and an outside space. In particular, a seal, for example, an O-ring seal, can be provided between the collector and the flange member. In particular, in case of such an arrangement, the cooler block can be designed not only as tubular cooler but alternatively also as a disk stack cooler. In this case, a collector can be a channel formed by overlapping openings of the disks, wherein the upper disk plate of the stack represents a floor member.
[0013] In an embodiment of the invention, the collector and the floor member together can be completely formed as a soldered unit from aluminum components. Such a solution is particularly safe and can be manufactured in a coolant-tight and cost-effective manner.
[0014] In a further embodiment of the invention, the flange member can be connected to the suction tube in a firmly bonded manner, preferably by means of adhesive bonding and/or welding, particularly friction welding. Apart from the secure and durable fastening, the number of required seals can be minimized in such a configuration. Alternatively or additionally, depending on the requirements, screwing, riveting or other fastening of the flange member to the suction tube can also be carried out.
[0015] Further, the flange member can be connectable to the suction tube via a substantially circular ring-shaped area, for example, by friction welding. In case of a circular joint, friction welding can be generated in a simple, cost-effective and secure manner via a highly dynamic vibratory movement in circular direction.
[0016] 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
[0017] 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 limitive of the present invention, and wherein:
[0018] FIG. 1 shows a schematic illustration of a charge air intercooler according to the prior art;
[0019] FIG. 2 shows a spatial illustration of a first example of a charge air intercooler according to the invention;
[0020] FIG. 3 shows a sectional view of the charge air intercooler from FIG. 2 ;
[0021] FIGS. 4 a and 4 b show two exploded drawings of the charge air intercooler from FIG. 2 from different perspectives;
[0022] FIG. 5 shows a schematic sectional view of a second exemplary embodiment of the charge air intercooler according to the invention;
[0023] FIG. 6 shows a sectional view of a third exemplary embodiment of a charge air intercooler according to the invention;
[0024] FIG. 7 shows a spatial view of the charge air intercooler from FIG. 6 ; and
[0025] FIG. 8 shows a schematic top view of a fourth exemplary embodiment of a charge air intercooler according to the invention.
DETAILED DESCRIPTION
[0026] The charge air intercooler shown in FIG. 1 shows a cooler block formed from a bundle of flat tubes 1 with ribs 1 a arranged therebetween. The flat tubes 1 form channels for a liquid coolant which is distributed via a collector 2 with coolant connections 3 to the channels 1 . At the end of the channels 1 , the coolant is deflected in a second collector 4 so that the charge air intercooler has a U-flow cooler-type design. The channels or flat tubes 1 open out in a floor member 5 of the collector 2 , which floor member is plate-shaped here and extends on the edge side beyond the cooler block and is equipped with mounting bores 5 a for fastening at an insertion opening in a suction tube (not illustrated in FIG. 1 ). The floor member 2 of the known indirect charge air intercooler thus forms at the same time a flange member for fastening to a suction tube.
[0027] The charge air intercooler according to the invention shown in FIG. 2 to FIG. 4 b comprises a two-row stack of flat tubes 1 between which, ribs 1 a are soldered on a flat surface. The charge air L flows around the flat tubes or channels 1 and ribs, wherein through the channels 1 , in turn, a liquid coolant can flow, for example of a low-temperature cooling circuit, for dissipating the heat.
[0028] The flat tubes 1 as a whole form a cooler block and open out with each of their ends into a floor member 5 which is formed as aluminum sheet metal part. After a mechanical preassembly, the two floor members 5 on the end sides, the flat tubes 1 and the ribs are soldered together in a soldering furnace. In particular, for further simplification and cost reduction, the floor members 5 can be designed as identical parts.
[0029] The first of the floor members 5 is part of a first collector 2 on the connection side of the charge air intercooler. The collector 2 is formed from the floor member 5 and a plastic injection molded part 6 which, at the same time, forms a collector compartment as well as a flange member for fastening the charge air intercooler in a gas-tight manner at an opening of a suction tube 7 (see sectional view FIG. 3 ).
[0030] The flange member 6 has a circumferentially extending collar 8 which interacts with a crimping 9 of the floor member 5 , in the present case a corrugated, slotted crimping. For this, an O-ring seal is inserted between collar 8 and floor member 5 , whereupon the flange member 6 is attached with its collar 8 in a coolant-tight manner onto the floor member 9 . By deforming the corrugated, slotted crimping 9 , a firm connection of floor member 5 and flange member or collector compartment 6 is created. Alternatively or additionally, this can also be carried out by latching, adhesive bonding or other fastening measures.
[0031] A circumferential flange face 10 having screw holes 10 a extends on the side of the collar 8 of the flange member 6 , by means of which flange face, a gas-tight fastening of the flange member 6 at an edge of the suction tube opening is carried out. For this, a further groove for inserting an O-ring seal in the flange face 10 and/or at the suction tube opening can be provided.
[0032] Furthermore, two nozzle-like coolant connections 3 are integrally formed on the flange member 6 . For distributing the coolant flows to feed channels and return channels 1 , in addition, a partition wall 12 is provided between the coolant connections 3 , which wall is likewise made of the same material and integrally formed on the flange member 6 .
[0033] On the opposite side of the flat tubes 1 , the second floor member 5 is connected in an analog manner to the second collector compartment 13 . The latter forms a hollow space above the tube ends so that the coolant flow from the flat feed tubes 1 is deflected by 180° into the flat return tubes 1 .
[0034] Advantageously, the cooler block is also supported on the side of the second collector 4 with respect to the suction tube, for example by a holder of the second collector compartment 13 , which holder is made of an elastic material (not illustrated).
[0035] FIG. 5 shows a second exemplary embodiment of the invention, wherein in contrast to the first exemplary embodiment, a different kind of sealing is selected.
[0036] In this example too, a flange member 6 is designed at the same time as collector compartment made of plastic and having a partition wall 12 . However, in the present case, between a plate-shaped laterally protruding floor member 5 and the outer edge of the opening in the suction tube 7 , an O-ring seal 11 is provided which provides for a sealing between coolant and charge air.
[0037] The flange member 6 is attached on the floor member 5 in a supporting manner and the seal is attached on said floor element in a pressing manner, wherein an edge 14 of the flange member is continuously connected in a firmly bonding manner to a corresponding edge 15 circumferentially extending around the opening of the suction tube 7 . In the present case, the connection is carried out by welding the plastic material of suction tube 7 to the flange member 6 , for example by friction welding or ultrasonic welding. Alternatively or additionally, an adhesive bonding can also be carried out. For better positioning and fastening, the corresponding edges have in addition interlocking steps.
[0038] FIG. 6 and FIG. 7 show a third exemplary embodiment of the invention. In contrast to the preceding examples, the flange member 6 is not designed to be at the same time a collector compartment. Rather, the collector compartments and the floor members 5 are uniformly formed from aluminum and are soldered together with the flat tubes 1 and the coolant connection 3 in a soldering furnace.
[0039] The structural aluminum unit created in this manner consisting of cooler block 1 and collectors 2 , 4 (see FIG. 7 ) is held in the suction tube 7 by means of flange member 6 made of plastic (see FIG. 6 ). In the present case, the flange member 6 is screwed to the suction tube 7 using a seal 21 ; however, it can also be glued or welded.
[0040] The flange member 6 engages over the collector 2 of the charge air intercooler, wherein the coolant connections 3 of the collector penetrate through recesses in the flange member 6 . Said O-ring seals 17 between collector 2 and flange member 6 provide for a gas-tight separation of charge air and outside space. Thus, the flange member 6 forms a gas-tight partition wall between charge air and outside space.
[0041] At the opposite end of the charge air intercooler, the latter is supported with respect to an inner wall of the suction tube 7 with a second collector, in which the coolant is deflected, wherein for a better damping of vibrations, an elastic insert 18 is provided between collector 4 and suction tube wall.
[0042] It is to be understood that in the exemplary embodiment according to FIG. 6 and FIG. 7 , principally any charge air intercooler construction can be used without departing from the inventive principle of sealed fastening in the suction tube. For example, the charge air intercooler can also be formed as disk stack cooler (not illustrated). In case of such a construction, other structures of the charge air intercooler with collector and floor member are to be identified. In this case, a collector can be understood as a channel formed by overlapping openings of the disks, wherein for example an upper base plate of the stack represents a floor member.
[0043] FIG. 8 shows a fourth exemplary embodiment of the invention which is substantially a modification of the third exemplary embodiment. Here too, the flange member 6 is designed as plastic molded part which engages over a collector 2 and has an opening 19 with a sealing ring 17 , which opening is penetrated by coolant connections 3 .
[0044] As a further development, an edge of flange member 6 is connected to the suction tube made of plastic and has a circular ring shape so that initially, a circular ring-shaped contact surface 20 is present. Subsequently, by friction welding, a firmly bonded connection of flange member 6 and suction tube 7 is carried out in a simple, secure and cost-effective manner. Due to the circular ring-shaped configuration of the surface 2 , the friction welding can be carried in a particular advantageous manner by means of dynamic oscillations or torsional vibrations about a circle center (direction of the vibration arrow V). Circular friction welding is in particular advantageous if the circular seal 17 is not highly loaded. In case that the seal is rotated on the cooler collector surface during friction welding, the seal is then possibly better protected against damage. Here, in particular such sealing rings are suitable which have certain sliding properties. Due to a rotational movement during friction welding, the risk of damage to the seal is reduced.
[0045] It is to be understood that depending on the requirements, the specific features of the individual exemplary embodiments can be combined with each other. Provided that said features do not require special materials, the latter can be selected as desired. Within this context, the suction tube can be made, for example, of plastic but also of aluminum.
[0046] 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 are to be included within the scope of the following claims. | A charge air intercooler for arrangement in a suction tube is provided that includes a plurality of channels through which coolant flows, forming a cooler block around which charge air can flow, wherein the cooler block is connectable to a floor member and wherein a collector has at least one coolant connection. The charge air intercooler can be fastened in an opening of the suction tube via a flange member, the flange member and the floor member being separate components. | 5 |
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application is based on and claims domestic priority benefits under 35 USC §119(e) from U.S. Provisional Application Ser. No. 60/791,431 filed on Apr. 13, 2006, the entire content of which is expressly incorporated hereinto by reference.
FIELD OF THE INVENTION
[0002] The present invention relates generally to the field of chemical treatments of comminuted cellulosic fibrous material. In especially preferred embodiments, the present invention relates to processes and apparatus for the alkaline pulping of comminuted hardwoods.
BACKGROUND AND SUMMARY OF THE INVENTION
[0003] Chemical cooking of hardwoods can typically result in greater pulp rejects as compared to pulp obtained from the chemical cooking of softwoods at Kappa numbers of 17 and greater. In this regard, the present applicants have discovered that the middle lamella in hardwoods have substantial amounts of guaiacyl lignin (g-lignin) on a cellular level in the middle lamella as compared to the presence of syringyl lignin (s-lignin). Specifically, the lignin in the middle lamella of hardwoods is predominantly g-lignin. The middle lamella of softwood cells will typically be substantially entirely comprised of g-lignin.
[0004] Since s-lignin is predominantly found in the secondary walls of hardwoods and is more easily dissolved during the cooking process, the cooking conditions to obtain the same Kappa number pulp from hardwoods tends to be less harsh as compared to the cooking conditions to obtain pulp from softwoods. In order to increase pulp yield it would be desirable to cook hardwoods to a higher Kappa number but such a practice is conventionally not possible since the amount of rejects would increase to a point that would not be commercially feasible. By way of comparison, while softwoods may be cooked under relatively harsh conditions using higher temperature and higher alkali charge to obtain the same Kappa number as hardwood (e.g., due to the presence of substantially all g-lignin in the middle lamella and well as secondary walls), this harsh cooking condition which promotes the degradation of g-lignin in the middle lamella result in producing substantially lower rejects level than when cooking hardwoods to a Kappa number of about 30. At a Kappa number of about 30, softwoods have a reject level less than 1% while hardwoods show a rejects level of higher than 20%. Thus, for hardwoods, conventional cooking conditions are selected so as to achieve a Kappa number of less than about 20, and typically less than about 17 so as to achieve an acceptably low amount of rejects.
[0005] It has now been discovered that rejects from cooking hardwoods at a given Kappa number can be reduced by subjecting the hardwoods to specific cooking conditions at the end of cooking. According to the present invention, therefore, alkaline cooking processes and apparatus, especially those useful for hardwoods, are provided which aim to increase the Kappa number of the hardwood pulp at the end of cook to levels above 17, but with much lower rejects levels. The present invention may be combined with an effective oxygen delignification stage to reduce the kappa number below 17. The present invention therefore contributes to benefits in respect to overall pulping yield and pulp strength.
[0006] It has been discovered that s-lignin reacts faster than g-lignin and that there exists a higher proportion of g-lignin at the end of a hardwood cook as compared to at the beginning of the cook. Thus, when cooking hardwoods, relatively harsher cooking conditions (e.g., higher cooking temperatures) at the end of the cooking have been discovered to decrease the percentage of pulp rejects at a given Kappa number as a result of g-lignin breakdown.
[0007] According to certain aspects of this invention, methods and systems are provided for continuously producing chemical cellulose pulp from a slurry of comminuted hardwood material by subjecting the slurry of comminuted hardwood material to a first cooking stage under conditions sufficient to reduce syringyl lignin (s-lignin) content in the hardwood material as compared to guaiacyl lignin (g-lignin) content therein, and thereafter subjecting the slurry of comminuted hardwood material to a second cooking stage under conditions sufficient to reduce the g-lignin content remaining therein after the first cooking stage.
[0008] In some embodiments, the first stage of cooking of the hardwood material (that is the treatment stage after pretreatment or impregnation) is practiced so as to subject the hardwood material to a temperature of between about 120° C. to about 170° C. at about 2 to about 10% effective alkaline charge as (EA) NaOH on wood and/or so that the Kappa number for the cooked hardwood material which exits the first cooking stage is between about 30 to about 100.
[0009] According to other preferred embodiments, the first cooking stage is conducted under a low sulfidity condition of less than about 20% sulfidity. Such a low sulfidity condition of the first cooking stage may be performed, if necessary, by adding a sufficient amount of preferably anthroquinone and/or polysulfide.
[0010] The second cooking stage according to some embodiments of the invention is practiced so as to subject the slurry of hardwood material to a temperature of between about 130° C. to about 180° C. at about 2 to about 10% effective alkaline charge as (EA) NaOH on wood and/or so that the Kappa number for the cooked hardwood material which exits the second cooking stage is between about 15 to about 30.
[0011] It is preferred in some embodiments of the invention that the second cooking stage be conducted under a higher sulfidity condition of greater than about 20% sulfidity with or without the addition of anthraquinone and/or polysulfide.
[0012] The comminuted hardwood material may optionally be pretreated. If employed, the pretreatment occurs prior to the first cooking zone at about 20 to about 70% of the total effective alkaline charge as (EA) NaOH on wood at a temperature between about 80 to about 120° C.
[0013] These and other aspects and advantages will become more apparent after careful consideration is given to the following detailed description of the preferred exemplary embodiments thereof.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS
[0014] Reference will hereinafter be made to the accompanying drawings, wherein like reference numerals throughout the various FIGURES denote like structural elements, and wherein;
[0015] FIG. 1 is a schematic presentation of exemplary apparatus for practicing the method according to the present invention, and comprising an exemplary system according to the present invention;
[0016] FIG. 2 is a graph of the percent lignin from the original lignin of the cellulose material remaining at each of the sample points during a hardwood cook; and
[0017] FIG. 3 is a graph representing the ratio of s-lignin to g-lignin at various stages of a hardwood cook.
DETAILED DESCRIPTION OF THE INVENTION
[0018] Accompanying FIG. 1 illustrates one preferred embodiment of the present invention. In this regard, FIG. 1 illustrates a comminuted cellulosic fibrous material treatment system 10 consisting essentially of or comprising a continuous digester 11 having a continuous digester feed system 12 . Feed system 12 may be a LO-LEVEL® feed system or a TURBOFEED® system both as sold by Andritz Inc. but any conventional feed system for introducing, steaming, and slurrying comminuted cellulosic fibrous material may be used; and/or one or more separate impregnation vessels may be used; and/or unconventional systems, such as those including equipment and/or a chip bin in the wood yard with pumping to the digester. Also in some circumstances a plurality of impregnation vessels may be used, with slurry pumped from a particular vessel once impregnation with, or without, cooking additive is complete (or will complete during pumping).
[0019] Comminuted cellulosic fibrous material, for example, in the form of hardwood chips 13 , are introduced to feed system 12 , as described in U.S. Pat. Nos. 5,763,075; 6,106,668; 6,325,890; 6,551,462; 6,336,993; 6,841,042 (the entire content of each patent being expressly incorporated hereinto by reference), and marketed by Andritz Inc. under the trademark TURBOFEED®; or a feed system as described in U.S. Pat. Nos. 5,476,572; 5,700,355; 5,968,314 (the entire content of each patent being expressly incorporated hereinto by reference), and marketed by Andritz Inc. under the trademark LO-LEVEL® which may include forwarding the chips to steam treatment in a vessel 14 , which is preferably a vessel as described in U.S. Pat. Nos. 5,500,083; 5,617,975; 5,628,873; 4,958,741; and 5,700,355 (the entire content of each patent being expressly incorporated hereinto by reference), and marketed by Andritz Inc. under the trademark DIAMONDBACK®, though other types of steaming vessels may be used. From the vessel the chips pass through equipment such as a metering device connected to a conduit, which is preferably a Chip Tube provided by Andritz Inc. The slurry of chips and liquid is fed to the impregnation vessel (if used) or to the digester 11 via a pressurizing means.
[0020] The slurry pressurized, typically, to a pressure of between about 5 and 15 bar and propels the slurry via conduit 21 to the top of the continuous digester 11 . Excess liquor contained in the slurry is removed from the slurry at the inlet of the digester 11 by a separating device 22 , typically a conventional Top Separator, and the excess liquid is removed and returned to feed system 12 via conduit 23 . During treatment within vessel 14 , the slurry of hardwood material may be pretreated at an alkaline charge of between about 20 to about 70% of total effective alkaline (EA) NaOH charge on wood at a temperature between about 80 to about 120° C., preferably between about 100 to about 110° C.
[0021] Feed system 12 also typically includes conventional non-illustrated devices such as in-line drainer, level tank, and make-up liquor pump. Cooking liquor, for example, kraft white liquor (WL) is typically provided to the level tank (not shown) as is conventional.
[0022] The pretreated hardwood material (which may, but not necessarily, have been treated in an impregnation vessel) fed via line 21 is subjected to a first cooking stage in digester 11 . However, in accordance with the present invention, the pretreatment of the hardwood material as described above is not absolutely necessary as the hardwood material may be fed directly into the digester 11 . Whether or not the hardwood material is pretreated, the first cook within digester 11 is conducted under low sulfidity conditions (i.e., 0-20% sulfidity) using a beneficial additive such as anthroquinone (AQ) and/or polysulfide. The first cooking stage in digester 11 is conducted at temperatures of between about 120 to about 170° C. using an alkaline charge of between about 2 to about 10% effective alkaline (EA) NaOH charge on wood. The cooked hardwood material exits digester 11 via line 30 having a Kappa number of between about 30 to about 100 (preferably between about 40 to about 60).
[0023] The hardwood material after the first cooking stage in digester 11 has a higher proportion of g-lignin relative to s-lignin than at the beginning of the first cooking stage. High concentration of s-lignin in surrounding liquor may interfere with the dissolution of g-lignin remaining in the hardwood material. To reduce this interference, it may be necessary to wash the hardwood material following the first cooking stage in digester 11 . Thus, the hardwood material may optionally be transferred to a wash vessel 32 via line 30 and subjected to wash conditions with a wash liquor introduced via line 34 . Spent wash liquor is removed from the wash vessel 32 via line 36 . Since the wash stage within wash vessel 32 reduces the s-lignin in surrounding liquor, any cooking additives which could later be used would not be detrimentally consumed by the already dissolved s-lignin in the surrounding liquor.
[0024] The washed pulp which exits the optional wash vessel 32 via line 38 is directed to a digester 40 where a second cooking stage is conducted so as to further breakdown and reduce the g-lignin content in the hardwood material. Breakdown of g-lignin can be accomplished by use of high sulfidity cooking liquor (i.e., greater than about 20% sulfidity, and preferably between about 25 to about 40% sulfidity) with or without AQ and/or polysulfide. (See for example U.S. Pat. No. 6,576,084, the entire content is expressly incorporated hereinto by reference). Other cooking chemicals that work well under cooking conditions, such as sulfite, could also be used alone or in conjunction with AQ and/or polysulfide as mentioned above.
[0025] The second cooking stage in digester 40 is conducted at a temperature between about 130 to about 180° C., preferably between about 140 to about 180° C., with an alkali charge of between about 2 to about 10% EA charge on wood (original wood charge) and a Kappa number at the beginning of the second cooking stage of between about 30 to about 100 (preferably between about 40 to about 60). During this phase, it may be advantageous (but not always necessary) to increase the temperature to above that of the first cooking stage.
[0026] If sufficient alkali has not been provided initially at the beginning of the second cooking stage, it may be necessary to introduce additional white liquor to digester 40 during the second cook stage prior to removal from digester 40 in a second location. If this second addition of white liquor is made at the end of the second cook stage, it is preferred that the hardwood material be allowed to continue to cook at a temperature of at least about 130°. At the point where the hardwood cellulosic material exits the digester 40 via line 42 , the Kappa number will preferably be between 15 to 30, more preferably between about 17 to about 30.
[0027] Important to the present invention is that the hardwood material is divided into two distinct cooking stages. The H-factor achieved at the end of the second cooking stage is as least 50% of the total H-factor that is achieved for the entire cook. Stated another way, the H-factor achieved through the first cooking stage is less than 50% of the H-factor achieved for the entire cook (i.e., at the end of the second cooking stage).
[0028] It is also possible that the cooking stages, and washing stage if used, are preformed in a single digester vessel. If a single vessel is used the same operating parameters for each stage as described would be used and end of stage would not require intermediate transfer of material to multiple vessels.
[0029] The first and second cooking stages conducted in digesters 11 and 40 , respectively, or in a single digester vessel, is preferably conducted in accordance with one or more of the processes described more fully in U.S. Pat. Nos. 5,489,363; 5,536,366; 5,547,012; 5,575,890; 5,620,562; and 5,662,775 (the entire contents of each such patent being expressly incorporated hereinto by reference). The processes and apparatus disclosed in these patents are marketed under the trademark LO-SOLIDS® Cooking by Andritz Inc. of Glens Falls, N.Y.
[0030] The processes and apparatus of the present invention produce a pulp low in HexA content as a result of the relatively high temperature of the new treatment and/or cooking in the second cooking stage. This low HexA pulp favors oxygen delignification conditions which in turn provides for a low Kappa number pulp to a subsequent bleaching process. See in this regard, U.S. Pat. Nos. 6,776,876 and 6,475,338, the entire content of each being expressly incorporated hereinto by reference. The low Kappa number pulp may therefore be bleached using less chemicals thereby resulting in lower effluent loading. The following non-limiting example further illustrates the present invention.
EXAMPLE 1
[0031] A hardwood cooking cycle was performed using a total EA (effective alkaline as NaOH) charge of 18% introduced during the impregnation, first cook and second cook stages. The following conditions were used during each of the stages:
[0032] Impregnation:
60% of the total EA or 10.8% EA charged Impregnation temperature of 110° C. Time to impregnation temperature=15 minutes Time at impregnation temperature=30 minutes
[0037] 1 st Cook Stage:
25% of the total EA or 4.5% EA added at beginning of cook Cook temperature=140° C. Time to heat to cook temperature=15 minutes Time at cook temperature=60 minutes
[0042] 2 nd Cook Stage:
15% of total EA or 2.7% EA added at beginning of cook Cook temperature=158° C. Time at cook temperature=76 minutes
[0046] From this set of cooking conditions, the high temperature in the second stage of the cook gave lower Kappa number and at least 30% lower reject rate than the set of cooking conditions using 140° C. cooking temperature in both cook stages under the same alkali charge and the same H-factor.
EXAMPLE 2
[0047] A hardwood cooking cycle was performed using a total EA (effective alkaline as NaOH) charge of 17.5% introduced during the impregnation, first (or upper) cook and second (or lower) cook sequences. The following conditions were used during each of the cook sequences:
[0048] Impregnation:
50% of the total EA or 8.75% EA charged Impregnation temperature of 110° C. Time to impregnation temperature=15 minutes Time at impregnation temperature=30 minutes
[0053] 1 st (Upper) Cook:
30% of the total EA or 5.25% EA added at beginning of cook Cook temperature=155° C. Time to heat to cook temperature=15 minutes Time at cook temperature=60 minutes
[0058] 2 nd (Lower) Cook:
20% of total EA or 3.5% EA added at beginning of cook Cook temperature=156° C. Time at cook temperature=120 minutes
[0062] A sample of the cellulosic material (wood chips) was taken after impregnation was complete and tested for s-lignin and g-lignin in the laboratory using the method described in Lin et al, “Methods in Lignin Chemistry”, Springer-Verlag, Berlin (1992) (the entire content of which is expressly incorporated hereinto by reference). In addition, samples of the cellulosic material (wood chips) were taken at the midpoint of cook (e.g., about 90 minutes from the beginning of impregnation and at the end of the 1 st (upper) cook (e.g., about 120 minutes from the beginning of impregnation). Each such sample was likewise analyzed for s-lignin and g-lignin content. Finally, a sample was also taken at the mid point of the 2 nd (lower) cook (e.g., about 180 minutes from the beginning of impregnation). No analysis for s-lignin and g-lignin in the final pulp produced was made since the lignin content generally is so low that it is difficult to accurately analyze for the s-lignin and g-lignin species.
[0063] Accompanying FIG. 2 is a plot of the percent of lignin from the original cellulosic material remaining at each of the sample points. At the beginning of impregnation, 100% of the lignin is present, but by the end of the 2 nd (lower) cook zone only about 3% of the lignin remains. As a general rule, wood chips prior to treatment contain about 24% lignin which means from the data of FIG. 2 the amount of lignin is only about 0.72% of the wood chips and thus any analysis of s-lignin and g-lignin content would not be accurate.
[0064] FIG. 3 present data that shows the change in the ratio of s-lignin to g-lignin as the cook described above progressed. The first ratio of 2.74 is the initial ratio before the addition of any liquor or any treatment. The second ratio of 2.87 is at end of impregnation. The third and fourth ratios of 2.64 and 2.54 are respectively at the middle of the first cook stage and at the end of the first cook stage. The fifth and final ratio of 2.47 is at the middle of the second cook stage.
[0065] The data of FIG. 3 thus suggests that the s-lignin is being broken down or dissolved at a faster rate than that of the g-lignin. As a result, the g-lignin content remains present on a cellular level which requires a different set of conditions to cause it to break apart and be destroyed or dissolved. In order to destroy the g-lignin, therefore, operating conditions in the digester must change in the later stages of the cook. Specifically, according to the present invention, the later stages of the cook require a higher temperature as compared to the early stages to ensure that the g-lignin is destroyed and to improve the yield (thereby reducing the rejects) and physical properties of the pulp.
[0066] While the invention has been described in connection with what is presently considered to be the most practical and preferred embodiments, it is to be understood that the invention is not to be limited to the disclosed embodiment, but on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims. | Hardwood pulp rejects at a given Kappa number can be reduced by subjecting the hardwood pulp to specified cooking conditions at the end of cooking. In this regard, it has been discovered that s-lignin reacts faster than g-lignin and that there exists a higher proportion of g-lignin at the end of a hardwood cook as compared to the g-lignin present at the beginning of the cook. Thus, when cooking hardwoods, relatively harsher cooking conditions (e.g., higher cooking temperatures) at the end of the cooking have been discovered to decrease the g-lignin content which in turn decreases the percentage of pulp rejects at a given Kappa number. In preferred embodiments, methods and systems are provided for continuously producing chemical cellulose pulp from a slurry of comminuted hardwood material by subjecting the slurry of comminuted hardwood material to a first cooking stage under conditions sufficient to reduce syringyl lignin (s-lignin) content in the hardwood material as compared to guaiacyl lignin (g-lignin) content therein, and thereafter subjecting the slurry of comminuted hardwood material to a second cooking stage under conditions sufficient to reduce the g-lignin content remaining therein after the first cooking stage. | 3 |
This is a division of U.S. Pat. No. 4,745,343, application Ser. No. 812,054 filed Dec. 23, 1985, which is a division of application Ser. No. 651,742, filed Nov. 7, 1984, U.S. Pat. No. 4,543,345, which is a further division of application Ser. No. 405,723, filed Aug. 6, 1982, U.S. Pat. No. 4,486,691 and its parent application Ser. No. 165,131 filed July 2, 1980, abandoned.
This invention relates to light emitters. More specifically it relates to a flashlamp which generates a beam of light omnidirectionally in a horizontal plane and sharply controls the vertical distribution of the beam. This invention also relates to flashlamp discharge controlling methods, and more particularly to a method of achieving an effective candella power (ECP) flash for visual signaling. The method also uses widely varying capacitances which are small, lightweight and of low cost.
This invention also relates to radiation detectors, and more particularly to a controlled azimuth and elevation discriminating system.
A signaling effect may be produced by a flashing light. In applying this principle at airports, in the signaling of aircraft in flight as they are approaching the runways, an effective light beam is required which is omindirectional in the horizontal plane while extending in a controlled vertical beam from plus two degrees to plus ten degrees in the vertical plane. The sharp cut-off of the lower edge of the beam is required so that at zero degrees there will be a minimal effect upon motorists and upon the environment on the ground around the installation of the flashlamps.
Although electrical flashlamps for repetitive flashing are often thought of as being utilized in applications for signaling aircraft, there are also other applications. Those other applications include warning beacons for obstructions, lights on moving vehicles, photography, and flash photolysis of chemicals. When a flashing light is utilized in photography, the flash output is accumulated on film so that the results of a low-intensity, long-duration flash are essentially equal to the results of a high-intensity, short-duraction flash of the same color. When utilized in systems in which the human eye functions as the flash detector, the effects are much the same as the effects achieved on film, i.e., the effect is cumulative. However, the accumulation occurs, in the case of the human eye, only when the duration of the flash is less than about onetwentieth of a second and the interval between flashes exceeds about two-tenths of a second.
Observation of flashing light is five times more effectively detected by the human eye than the output of a steadily emitted light of the same operating intensity. The five fold increase in effective signaling, which the flashing light achieves, is determined by dividing the intensity of the light by the Blondel-Rey constant of 0.2. Blondel and Rey, and others, arrived at the figure of 0.2 through a wide range of empirical experiments involving the perception of flashing lights. Douglas et al. at the National Bureau of Standards of the United States established 0.2 as the practical standard constant used in determinning the Effective Candella Power of flashing lights for approved use at airports in the United States.
There is a need for economical flashing signal lights at airports, and such lights should be variable in intensity from five thousand plus or minus two thousand candellas ECP to fifteen hundred plus or minus four hundred fifty candellas ECP to seven hundred plus or minus two hundred candellas ECP. These intensities are needed in a beam which is omnidirectional in the horizontal plane and extends from ten degrees above the horizon down to two degrees above the horizon with a very sharp cut off between two degrees and zero degrees. This sharp cut-off prevents interference with automobile traffic and other such ground activity and prevents other adverse environmental effects around the airport where such flashing lights are involved. In order to accommodate the greatest of these three levels of intensity, the beam intensity and the beam volume dictates an energy storage requirement in excess of fifty joules per flash at one flash per second.
In the past, emitting sharply controlled light beams where efficiency of energy input was a consideration typically was accomplished by using large and heavy lens arrays. The lenses were large in order to accurately refract the light from high energy point sources and create a beam viewed by a distant observer. Since great amounts of energy were not available from quite small point sources, because such sources would be melted, larger sources were used, and such larger sources required larger optics for sharp beam control. Where large refractors were used in the larger optics systems, attempts were made to minimize the sizes by moving them as close to the source as possible. However, moving the refractors close to the source meant that their heat tolerance had to be higher and their refractive power had to be greater for such shorter focal distances. Quite heavy thicknesses of glass were often used. A drawback of such thick glass was that, although the refractive power was increased, the transmission losses were also increased.
Lighter weight plastic refractors were also used. However, such refractors have less refractive power and do not completely focus an axially located source. When such axially located source is not completely focused by the refractor, very sharp beam cut-off is not achieved, although lightweight low energy broad pattern control very suitable for street and area lighting is accomplished.
Typical beam emitters and panoramic light emitters are shown in U.S. Pat. Nos. 3,739,169 issued June 12, 1973, 3,818,218 issued June 18, 1974, 3,249,750 issued May 3, 1966, 3,448,260 issued June 3, 1969, 3,775,605 issued Nov. 27, 1973 3,697,736 issued Oct. 10, 1972, 3,705,303 issued Dec. 5, 1972, 3,427,747 issued Feb. 11, 1969, and 3,766,375 issued Oct. 16, 1973. The arrangements shown in the constructions illustrated by these patents utilize highly concentrated sources for the beam or fail to produce a beam with a sharp cut-off. In those cases where the source of the beam is distributed, the energy is dispersed and the surface temperature and life of materials is improved but the characteristics of the beam are sacrificed.
The operative mechanisms of flashlamps are gradually ionized and then deionized through the duration of the flash. This is true whether the flashlamp is electrically powered or chemically powered. The gradual ionization and then deionization is a continuous process throughout the ionized state and is controlled by the rate at which energy is made available to the ionizable material and by the rate at which energy is removed from such material. When the energy is removed at a higher rate than that at which it is being made available, the ionization decreases.
In the past, energy was put into any specific flashlamp for flashing purposes only at two impedance levels. The high impedance energy input which initiated ionization was limited in voltage and energy to a level which would not damage the flashtube envelope. This high impedance energy has been termed the "trigger" and has been specified for reliable initiation of ionization, or "triggering", for different lamps and lamp applications as follows: Class I at 4 kv min., 3 microseconds maximum rise time, with 3.2 millijoules typical trigger coil input; Class II at 10 kv min., 3 microseconds maximum rise time, with 20 millijoules typical trigger coil input; and Class III at 20 kv min., with 0.12 joules typical trigger coil input.
In earlier circuits the main discharge terminals of the flashlamp were connected to the main energy storage capacitor, and the voltage of that capacitor had to be maintained during triggering in a narrow voltage range. In other words, the main energy storage capacitor voltage had to be high enough to transfer increasing energy into the lamp ionizable material before the trigger energy was dissipated. This minimum voltage level, called the Minimum Flashing Requirement, was coordinated with a specified trigger pulse in one of the classes stated above. The maximum voltage level of the main energy storage capacitor was specified to assure that the lamp would not fire without trigger energy. This maximum voltage level is termed the Maximum Anode Voltage. Energy stored at a voltage between the two limits, i.e., Maximum Anode Voltage to minimum flashing requirement, determines a second general impedance level. Such stored voltage supports increasing ionization as the trigger energy is used up. Such stored energy also was utilized to supply the major and remaining portion of the energy used in the flash.
The main energy storage capacitor was operated in the voltage range between the maximum anode voltage and the minimum flashing requirement. For many flashlamps, this constituted a variation of plus or minus twenty percent of the main energy storage capacitance voltage between the maximum anode voltage and the minimum flashing requirement. A mathematical determination of such energy stored in the capacitor, as just described, is, in joules, equal to one-half the capacity of the capacitor expressed in farads times the voltage on the capacitor squared.
Electrolytic capacitors are small and inexpensive for their energy storage capability compared to foil-and-film capacitors operating at the one kv level. This level is particularly suited to many flashlamps. The application of electrolytic capacitors as discharging energy storage devices has been less than satisfactory heretofore because they are typically manufactured in a capacity tolerance of a plus fifty and minus ten percent of their capacity rating. Because they are electro-chemical devices, the characteristics of the electrolytic capacitors are further subject to temperature variations. Heretofore a specified Effective Candella Power from a flashlamp was obtained with a tolerance of plus or minus ten percent of the specified ECP. When this ECP was combined with optical variations of plus or minus ten percent of mean beam strength, a luminaire output variation was produced of less than plus or minus twenty-five percent by using foil-and-film capacitors of plus or minus ten percent tolerance charged to a voltage which was controlled to within plus or minus one percent. In an attempt to utilize electrolytic capacitors as discharging energy storage devices, that is, as devices turned off only by lamp extinction after discharging more than twenty percent of their voltage, such capacitors were charged through a resistance to effect a constant charge in a specified fraction of a second rather than to a constant voltage. Capacitors of plus fifty percent tolerance charged, of course, to a lower voltage than did capacitors of minus ten percent tolerance. Stored charge in Coulombs equals the product of Capacity times Volts. The voltage variation was 1.5/0.90 or 1.66 to 1 before any temperature variations, and compensating effors to reduce the voltage variations increased the variations in the stored energy. When a different level of intensity was required from the same flashing signal light, different banks of capacitors were connected to the lamps in order to maintain the lamp voltages required.
Typical prior art patents concerning flashlamp controlled discharge methods are as follows: U.S. Pat. No. 3,355,625 issued Nov. 28, 1967, No. 3,413,518 issued Nov. 26, 1968, No. 3,349,284 issued Oct. 24, 1967, and 3,551,741 issued Dec. 29, 1970.
The present invention overcomes the difficulties and problems of the prior art in that it uses dynamic impedance matching methods which allow the use of main energy storage capacitors having much wider voltage variations than those heretofore used. The device of the present invention utilizes a distributed focal plane which allows finer detail and also allows the use of a distributed source which spreads the heat energy of the source, lowers its surface temperature and improves the life of its materials.
In the device of the present invention, a flashlamp and reflector may be replaced with a radiation detector to accommodate a sharply controlled omnidirectional azimuth and elevation discriminating system.
Accordingly, it is an object of the present invention to provide an improved panoramic light emitter having a very sharp cut-off in the vertical plane of the emitted light beam.
It is a further object of the present invention to provide a panoramic light emitter using distributed light sources which also distribute the heat associated with such sources.
It is a further object of the present invention to provide an improved panoramic light emitter utilizing a reflector which directs substantially all of the light beams incident thereon past the light source and avoids condensing the said beams in said source.
It is a further object of the present invention to provide an optical system which increases the resolution of variations of the beam edges.
It is a further object of the present invention to provide an optical system in which the distributed focal plane is panoramically imaged.
It is a further object of the present invention to provide an optical system in which a complete conical surface of a reflector is panoramically imaged.
It is a further object of the present invention to provide a flashlamp discharge control dynamically impedance matching the main energy storage capacitance to the load.
It is a further object of the present invention to provide a flashlamp discharge control system which incorporates lightweight capacitors for storing electrical energy for discharge into an arc load.
It is a further object of the present invention to provide a flashlamp discharge control system for varying the discharge of stored energy into the lamp over wide limits from pulse to pulse by varying only the voltage on the main energy storage capacitors.
It is a further object of the present invention to provide a flashlamp discharge control system which incorporates means to vary the pulse length of energy into the lamp so as to control the RMS current in the capacitor-lamp discharge circuit.
It is a further object of the present invention to provide a flashlamp discharge control system which incorporates means for providing longer wavelength outputs of the flashlamp by controlling the discharge current levels within the maximum capabilities of the flashlamp.
It is a further object of the present invention to provide a panoramic radiation receiver which is simultaneously sensitive to radiation from a plurality of directions.
It is a further object of the present invention to provide an improved panoramic radiation receiver which incorporates means for simultaneously detecting and discriminating among radiations from a plurality of directions.
It is a further object of this invention to provide an arc discharge control method for controlling the RMS current in the capacitor-arc discharge circuit.
These and yet additional objects and features of the invention will become apparent from the following detailed discussion of exemplary embodiments, and from the drawings and appended claims.
In a preferred form of the present invention, a flashlamp is provided for signaling aircraft approaching a runway. The flashlamp includes a refractor for receiving a plurality of beams of light and distributing said beams in a plurality of directions. The refractor also includes a plurality of lenses having a common focal plane. The flashlamp incorporates also an illuminator emitting a plurality of light beams, an a reflector disposed in the depth of field of the focal plane directing a portion of the light beams toward the refractor. The light beams are focused by the refractor to form of an image of the reflector in the far field of the refractor.
A second form of the invention is a radiation receiver for detecting radiation emanating from at least one source of radiation outside of the receiver. The receiver includes at least one radiation sensitive element and a refractor. The refractor includes a plurality of prisms distributed on the walls of the refractor and forming a distributed focal plane adjacent to the refractor. The radiation sensitive element is located in the depth of field of the focal plane, and the image of at least one portion of the source of radiation is focused by the refractor from the far field of the refractor onto the radiation sensitive element.
A further form of the invention is an arc discharge control circuit which includes a pulsing electrical arc for dissipating energy, a storage member comprising a plurality of capacitors adapted to store energy at different voltages and to initiate their individual discharges at successively lower voltages, and means for initiating the flow of energy from the storage member into the arc.
BRIEF DESCRIPTION OF THE DRAWINGS
For a complete understanding of this invention, reference should be made to the accompanying drawings in which:
FIG. 1 is a perspective view of the panoramic light emitter of the present invention mounted upon a vertical support member;
FIG. 2 is an enlarged cross-sectional view of the panoramic light emitter shown in FIG. 1 and showing light beams emanating therefrom focused in the far field and taken along lines 2-2;
FIG. 2A is an enlarged view of a portion of the panoramic light emitter shown in FIG. 2;
FIG. 2B is an enlarged section of the wall of the refractor portion of the panoramic light emitter shown in FIG. 2A and taken along lines 2B--2B;
FIG. 3 is an enlarged perspective view of a portion of FIG. 2 which principally comprises a circular flash tube and its associated reflector, surrounding the tube;
FIG. 4 is a perspective view of an alternative form of the flash tube in FIG. 3 and an alternative form of the associated reflector in FIG. 3;
FIG. 5 is a perspective view of an alternative form of a portion of the construction shown in FIG. 2, shown in enlarged scale, which portion is a matrix of photo diodes which may be installed in the construction of FIG. 2 in place of the circular lamp and reflector shown in FIG. 3 when the invention is adpated to be used as a radiation receiver;
FIG. 6 is a schematic drawing and block diagram of a flashlamp discharge control circuit for use with the panoramic light emitter shown in FIG. 1;
FIG. 7 is a schematic drawing of a basic flashlamp discharge control system, the concept of which is applied in the discharge control circuit of FIG. 6;
FIG. 8A is a graph of lamp discharge voltage waveforms with respect to time of the lamp of FIG. 7 under three conditions of selected Effective Candella Power;
FIG. 8B is a graph of the same conditions shown in FIG. 8A using a time base 100 times greater than that which is specified in FIG. 8A; and
FIG. 9 is a plan view of a runway equipped with a plurality of panoramic light emitters flashing in sequqence toward the end of an airport runway.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
As shown in FIGS. 1 and 9 the panoramic light emitter of the present invention is particularly adapted for installation adjacent the ends of airport runways. A series of such emitters is located so as to flash at fraction of a second intervals leading toward the runway and identifying the front corners of the runway. These lights in the series repeat themselves each every second so as to guide the pilots of aircraft safely to the landing. The emitters are mounted on vertical support members, as shown in FIG. 1 and are erected a minimal distance above the plane of the runway. As may be noted especially in FIGS. 1 and 9, the light emitters of the present invention are constructed to provide a flashing light in a 360° arc so that pilots of aircraft may immediately determine the proper landing end of the runway from innumerable points around the airport.
Referring now to FIG. 2, the panoramic light emitter comprises a plastic refractor 2 imaging a reflector 4 which is illuminated by a circular lamp 6. The top edge of the reflector 4 is imaged by horizontal lenses 8 on the outside of refractor 2 to create the bottom edge 10 of the light beam 12. The relationship of the optical components, refractor 2 and reflector 4, is maintained by insulators 14, supports 16, base pan 18 and clamp 20. Preferably, the clamp 20 extends all the way around the interface of pan 18 and refractor 2. The circular lamp 6, which is a form of flash tube, is triggered to its "on" state by high voltage generator 22. Heat is primarily removed by convection through the open bottom and open top of the reflector 4 and rises into dome 24 through which heat is transferred to the outside air. The cooled air within the dome 24 then falls down the interior walls of refractor 2 and of base pan 18 and between insulators 14 and supports 16 to repeat its convection cooling of reflector 4 and of the flash tube 6.
Base pan 18 and dome 24 are preferably constructed of lightweight aluminum, which is corrosion protected, as are supports 16 and clamp 20.
The reflector 4 is preferably formed of aluminum with a specular reflective surface 26. The surface 26 reflects at least eighty percent of the light which is incident upon it. Preferably, the surface has a clear anodized coating to insure a long life of reflectivity.
The reflector 4 is operated at the same voltage as trigger wire 28 (see FIG. 3) which is wrapped around flash tube 6 to avoid voltage breakdown. The reflector 4 is supported by low capacity insulators 14 to minimize the required trigger energy which is supplied in the 15 kv range. The nominal 15 kv energy is supplied by the high voltage generator 22 once each second to trigger the flash tube 6. The anode and cathode of flash tube 6 are by-passed with low inductance capacitors contained in the high voltage generator 22 directly to the return connection of the 15 kv high voltage generator 22, thus preventing the 15 kv energy from being expended anywhere other than in the flash tube 6. Such an arrangement reduces the insulation requirements in the light emitter 1.
Referring now to FIG. 3, the flash tube 6 and the reflector 4 form a source of illumination. The source is comprised of a generally conically shaped reflector 4 which is internally illuminated by circular flash tube 6. The generally conically shaped surface is optimized for the single turn circular flash tube which is illustrated by having each vertical section, when viewed in a plane which includes the vertical axis of the source, seen as a parabola with its focus at the tube 6. A generally conical surface for cooperation with a two-turn tube would itself have a different element shape. Because the reflector 4 and the tube 6 are within the depth of field of the focal plane of the associated refractor 2, they are accurately imaged in the vertical cross-section of beam 10. The electrodes 30 and 32, which are disposed in the adjacent ends of flash tube 6 are so close to each other that light variations caused by them are integrated in the horzontal plane by Blondel prisms 34 (see also FIG. 2B) on the interior surface of refractor 2.
Referring now to FIG. 4, a source similar to that shown in FIG. 3 is illustrated. The source in FIG. 4 is comprised of a generally conically surfaced reflector 4a illuminated by a linear flash tube 6a. The image 6a' of the flash tube 6a is located in the focal plane of a cooperating refractor (not shown) situated with respect to the reflector 4a in the same relationship as refractor 2 is situated with respect to reflector 4. When the image 6a' is viewed by the cooperating refractor, the image 6a' extends beyond and off the top edge of the reflector 4a. Because the image 6a' is at full reflected brightness at the top edge of the reflector 4a and does not exist off the reflector 4a, the image 6a' has a very sharp edge which is projected as a sharp edge of a beam.
Referring now to FIG. 5, a radiation sensitive matrix 36 is illustrated. The construction of the emitter 1, shown in FIG. 2 may be readily modified by substituting the matrix 36 for the combination of reflector 4 and flash tube 6, and with suitable sensitive electronic registry means the emitter construction becomes a radiation sensitive receiver which discriminates in azimuth and elevation. Matricies of custom photodiodes are recommended as being available on page 2 of EG&G Catalog entitled "Electro-Optics Division, Condensed Catalog" Salem, Massachusetts, printed January 1978. Each segment, of the group of segments 38a, 38b, 38c, 38d and 38e in the matrix 36, produces a separate electrical signal when radiation to which it is sensitive falls upon it. The matrix 36 is located in the focal plane of a cooperating refractor (not shown). The cooperating refractor for matrix 36 would not have Blondel prisms because integration in the horizontal plane is not desired. When the optical system which includes matrix 36 in its focal plane has a common axis vertically oriented, a signal from segment 38a indicates a source of radiation in the lower-most portion of the imaged far field. Similarly, a signal from segment 38b indicates a radiation source just above the lowermost portion of the imaged far field, but still below the center of the imaged far field. Similarly, a signal from segment 38c indicates a source of radiation above the center of the imaged far field, and a signal from segment 38d indicates a source of radiation at the top edge of the imaged far field. A signal from segment 38e indicates a source of radiation at the same elevation as the source of radiation imaged on 38d, but at a different azimuth. Electronic scanning of the segment signals eliminates the need for mechanical scanning in an omnidirectional azimuth and elevation discriminating receiver.
Referring now to FIG. 6, a schematic drawing and block diagram of a flashlamp discharge controlling circuit is shown for use with the panoramic light emitter shown in FIG. 1. Further detailed discussion of this figure will be reserved to follow the discussion of the schematic drawing in FIG. 7, the concept of which is applied to the discharge controlling circuit of FIG. 6.
In FIG. 7, most of the energy to be discharged into a flash tube 40 is stored in the electrolytic capacitor 42 at voltage levels which are usually below the Minimum Flashing Requirement Voltage specified by the lamp manufacturer. The conventional triggering of the lamp 40 is accomplished by discharging the trigger capacitor 44 through the trigger impedance transformer 46 when the "kindling" capacitor 48 is charged to a voltage level always above the Minimum Flashing Requirement and below the Maximum Anode Voltage. When the "kindling" capacitor 48 discharges down to a voltage below the capacitor 42, which "kindling" capacitor 48 discharging through the arc to a lower voltage constitutes a Dynamic Impedance Matching, then capacitor 42 begins to discharge through the diode 50 into the partially ionized lamp 40 and increases the ionization of the lamp 40 until discharged down to a voltage level which can no longer sustain ionization in the lamp. Then the lamp 40 ionization percentage gradually decreases, and the lamp impedance gradually rises to such a high value that, when the "kindling" capacitor 48 subsequently is recharged to a value above the lamp Minimum Flashing Requirement, the lamp 40 will conduct to such an insignificant extent as to be considered an open circuit, and the lamp is then considered extinguished.
The cycle timing of the circuit of FIG. 7 is complete in one second, and it repeats itself every second. Switch 52 and switch 54 operates at the same time and cycle once per second. Switch 56 and switch 58 are operated to change the Effective Candella Power of the lamp 40 output.
The circuit of FIG. 7 conveniently models the disclosed flashlamp discharge control method. At 0.25 seconds after the lamp 40 has been triggered, flashed, and allowed to cool, switch 52 is opened and switch 54 is closed. If switch 56 and switch 58 are opened, then the lowest Effective Candella Power has been selected. The lamp 40 Minimum Flashing Requirement is 250 volts, and Maximum Anode Voltage is 315 volts when it is a Radio Shack 272-1145 Flashlamp. The trigger impedance matching transformer, which may be a Radio Shack 272-1146, puts out a 4 kv minimum pulse when 250 volts from the trigger capacitor 44 is connected to the primary winding through switch 52. The trigger is a class 1 trigger in voltage and energy. When the power switch 54 is closed, the 240 volt 60 Hertz A.C. line source 60 is connected to the anode of the power rectifier 62 which is a 1 N 5062 rectifier, and current flows on 45 positive half cycles of the A.C. line source 60. This current through resistor 64 charges the 1.0 microfarad capacitor 48 to 300 volts and through resistors 64 and 66 charges the 0.1 microfarad trigger capacitor 44 to above 250 volts. Forty-five cycles after the power switch 54 was closed, the power switch 54 is open-circuited and the trigger switch 52 is closed. Three millijoules of energy flows from the trigger capacitor 44 into the primary of the trigger transformer 46, where its impedance is changed to produce a 4 kilovolt pulse from the secondary. That pulse is applied through a conductor of less than twelve inches in length to the trigger electrode 68 distributed along the outside wall of the lamp 40.
A portion of the 3 millijoules is then coupled through the high impedance wall of the lamp to the interior Xenon gas. Because the lamp cathode 70 is 4 kilovolts away from the trigger electrode 68 and the lamp anode 72 is held by the capacitor 48 to within 300 volts of 4 kilovolts away from the trigger electrode 68, the voltage stresses across the Xenon gas cause ionization of the gas. This reduces the anode-to-cathode impedance of the lamp 40, so that energy stored at 300 volts in "kindling" capacitor 48 will start to discharge into the lamp 40.
Referring momentarily to FIGS. 8A and 8B which depict lamp anode-to-cathode voltages, in conventional fashion the discharge of "kindling" capacitor 48 will follow the solid curves on the graphs of the lamp anode-to-cathode voltage with respect to time and a low Effective Candella Power flash will be the output.
Referring back to FIG. 7, resistor 66 allows the trigger capacitor 44 to be quickly discharged into the primary of transformer 46 without substantially affecting the charge on the capacitor 48 in 0.1 milliseconds. When medium power output is desired for each flash, the power switch 56 is closed. When the power switch 54 is closed, the 100 microfarad electrolytic capacitor 42 is charged through the resistor 74 more slowly than the "kindling" capacitor 48 is charged through its associated resistor 64.
The associated resistor 74 is chosen so that, at the end of 45 cycles of charging from the 60 Hertz line source 60, the electrolytic capacitor 42 has reached approximately 100 volts plus or minus the inverse capacity tolerance of the 100 microfarad electrolytic capacitor 42.
To discharge for a medium Effective Candella Power output from the flashlamp the previous sequence for a low power flash is initiated. However, when the 1.0 microfarad "kindling" capacitor 48 discharges down to just below the voltage level of the 100 microfarad capacitor 42, energy begins to flow from the main storage electrolytic capacitor 42 through the diode 50 and into the lamp 40. Referring momentarily again to FIGS. 8A and 8B, depicting lamp anode-to-cathode voltages, the discharge of the "kindling" capacitor 48 follows the solid curve from 300 volts down to 100 volts, and then it proceeds along the dotted line, supported by the discharge of the electrolytic capacitor 42 for a discharge of greater energy than the low power discharge.
Referring back to FIG. 7, when high power is desired for each flash, the power switch 56 and the power switch 58 are both closed. When the power switch 54 is closed, the 100 microfarad electrolytic capacitor 42 is charged through the resistor 74, and through the resistor 76, in parallel, and still more slowly than the "kindling" capacitor 48 is charged through its associated resistor 64. The resistor 76 is chosen so that, at the end of 45 cycles of charging from the 60 Hertz line source 60, the 100 microfarad capacitor 42 has reached approximately 150 volts plus or minus the inverse capacity tolerance of the 100 microfarad capacitor 42. To discharge for a high Effective Candella Power output from the flashlamp 40, the previous sequence for a low power flash is initiated. However, when the 1.0 microfarad "kindling" capacitor 48 discharges down to just below the voltage level of the 100 microfarad capacitor 42, energy begins to flow from the main energy storage electrolytic capacitor 42, through the diode 50, and into the lamp 40.
Referring momentarily again to FIGS. 8A and 8B, after conventional triggering of the lamp 40, the discharge of the "kindling" capacitor 48 follows the solid curve from 300 volts down to 150 volts and then proceeds along the dashed line, supported by the discharge of the electrolytic capacitor 42 for a discharge of greater energy than the medium power discharge.
The diode 50 is preferably Type 1N 3663 operated entirely within its manufacturer's integrated forward and reverse limits. Motorola, Inc., rates its 1N 3663 diode at a peak repetitive reverse voltage of 400 volts maximum at 25° C. diode case temperature and an average half-wave rectified forward current with a resistive load of 25 amperes at 150° C. case temperature. At 150° C., the instantaneous forward conduction drop at 25 amperes is 0.87 volts. The diode heating equivalent to that endured in a peak 1-cycle surge-current of 400 amperes from a 60 Hertz source when the case temperature is 150° C. is to be avoided.
Referring now to FIG. 6, the power line 78, rated at 240 volts 60 Hertz, center tapped for 120 volts 60 Hertz on either side of the grounded neutral conductor 80, supplies the charge and discharge timing and control logic module 82, a module which is a conventional one and wellknown to those skilled in the art of semi-conductor switching, and the optical relays 84, 86 and the interlock relay 88 through line fuses 90 and 92, and is connected to transient overvoltage limiters 94, 96. The fuse circuits include inductance, and the overvoltage limiters include by-pass capacitance, to prevent electromagnetic interference from passing into or out of the power line 78 at the flasher power supply. The interlock relay 88 is controlled by the power supply interlock switch 98 and flasher interlock switch 100 for safety purposes and controls power to the charge and discharge timing and control logic module 82, to the optional thermostatically controlled heater 102, controls the operation of line power semiconductor switch 104 and controls the 120 volt 60 Hertz current-limited trigger 106, and high signal input 108 from the system distant control box. The open circuiting of either one of the interlock switches 98 or 100 turns off all 120 volt and 240 volt circuits coming into the power supply which also turns off all optical isolator outputs from the logic module 82. Power at the power line 78 is controlled at the system distant control box (not shown) and only exists when the flashlamp system operation is desired by activating the system distant control box.
A plurality of flashlamp optical pulses from a plurality of locations distributed from the end of each airport runway is controlled in intensity and sequence from the system distant control box to prevent any single flash from occurring at the wrong time in a sequence which would mislead an aircraft pilot. Power at the power-line 78 is in parallel with the powerline connection of other similar flasher units so that intensity and sequence of flashing arc controlled entirely through the trigger 106 and high signal input 108 control wires.
When 120 volt/240 volt 60 Hertz grounded neutral power appears at the power line 78, the interlock relay 88 will close and turn on the power switch 104. The charge and discharge timing and control logic module 82 will reset its internal clock and start clocking the power line cycles in order to turn on the low optically controlled switch 84 for forty-five cycles of the 60 Hertz powerline 78.
If low intensity was selected at the system distant control box, then no 120 volt 60 Hertz voltage will appear at the high signal input 108 line, and the high optically controlled switch 86 will never turn on. If high intensity operation was selected, then 120 volt 60 Hertz voltage will appear continuously on the high signal input line 108, and the high optically controlled switch 86 will be turned on for the same forty-five cycles of the 60 Hertz powerline 78 for which the low switch 84 was turned on. If medium intensity operation was selected, then 120 volt 60 Hertz voltage will appear continuously on the high signal input line 108, but the high optically controlled switch 86 will be turned on only during the last fifteen cycles of the time in which the low switch 84 is on. This medium mode is accomplished by the lengthening of the 120 volt 60 Hertz voltage trigger signal in the control box from 0.25 seconds duration, which is 15 cycles of the 60 Hertz voltage trigger signal. The trigger signal is lengthened to prevent high charging through the high optically controlled switch 86, and the longer trigger signal voltage on line 106 is converted to a shorter charging time by the charge and discharge timing and control logic module 82.
Because the flashlamp discharge controlling method of this invention uses dynamic impedance matching to a capacitance whose voltage can be varied over a wide range, the system distant control box can be made to incrementally select any intensity of flash over a wide range from near minimum intensity to maximum intensity just by incrementally varying the length of the trigger signal produced at the distant control box. However, practical applications as airport signaling devices indicate that 5000, 1500 and 700 Effective Candella Powers are sufficient variations. Each time a trigger signal starts, the clock in the logic module 82 is reset and begins counting again. If another trigger signal is not received in 1.1 seconds, then the charging switches 84, 86 are turned off and the module 82, optically isolated outputs to the power Schmitt triggers 110, 112 are also turned off, and this allows the power Schmitt triggers 110, 112 to begin their 4 second discharge of the 2000 microfarad of electrolytic energy storage capacitance to below 50 volts. This assures that the lamp will not flash at a wrong time.
When a trigger signal is received by the logic module 82, one second plus or minus 4/60 of a second from the beginning of the preceding trigger signal, then that subsequent trigger signal is accepted for normal flasher operation and the logic module 82 passes a portion of the trigger signal through an optical isolator to the trigger amplifier 114. The trigger amplifier 114 derives its power from the charged electrolytic energy storage capacitance and passes the trigger signal through the cable 116 and the transient limiting resistors 118 and 120. The trigger signal is transient limited by the zener diode 122 and is time integrated by the resistor 124 and the capacitor 126 to enhance system noise immunity. When the capacitor 126 is charged to 8 volts by the processed trigger signal, then the five layer diode 128 turns on to begin an 8 volt discharge which is developed across the resistor 130 and turns on the transistor 132. The pulse output from the emitter of transistor 132 is current limited by the resistor 134 and turns on the triac 136. The triac gate is shunted by a resistance 138, built into the triac 136 which further enhances system noise immunity.
The supply voltage to traic 136 is limited to 340 volts by the zener diode 138 and allowed to ring for a greater A.C. component in the trigger voltage of the lamp 140 by the diode 142. The 0.3 microfarad lamp trigger capacitor 144 is charged to 340 volts through the diode 146 and the limiting resistor 148. The turn-on of the triac 136 discharges the 0.3 microfarad capacitor through the primary of the trigger transformer 150 which has a 50 to 1 turns ratio raising the trigger impedance so that a 15 kv class II trigger pulse is delivered to the lamp 140 through the trigger electrode 152. Because the return of the 15 kv pulse developed in the secondary of the trigger transformer 150 is directly by-passed through the 0.15 microfarad capacitor 154 to the lamp anode 156, and through the 0.15 microfarad capacitor 158 to the lamp cathode 160, the maximum available trigger energy is applied to the high impedance xenon gas inside the lamp 140 and begins to reduce that gas impedance.
Just prior to the start of the 120 volt 60 Hertz trigger signal pulse at the trigger line 106, the "kindling" capacitors 154, 158, 162 and 164, which are of identical ratings for this lamp 140, completed charging to 560 volts each in the polarity provided by the voltage multiplier diodes 166, 168, 170 and 172 and the charging current limited by the foil-and-film capacitors 174, 176 through the low power switch 84 and through the damping resistor 178. At the same time, most of the energy for the low 700 Effective Candella Power flash had been stored as a charge of constant current into the electrolytic capacitances 180, 182 at approximately 270 volts each in the polarity provided by the voltage multiplier diodes 184, 186, 188 and 190, and was current-limited by the foil-and-film capacitors 192 and 194. The power diodes 196 and 198 isolate the "kindling" capacitors 162 and 164 from the low ECP capacitances 180 and 182, and the resistor 200 damps transients. Storage of a portion of the main discharge energy at a voltage not much below the lamp 140 minimum operating requirement assures not only an easy dynamic impedance matching step from the "kindling" capacitors' impedance level while using only a minimal capacity at the "kindling" voltage level, but also provides an intermediate impedance step to the last main energy storage voltage, when that voltage is at a low value, for the medium 1500 Effective Candella Power flash output.
When medium intensity operation is selected, the "kindling" capacitors 154, 158, 162 and 164 and the low ECP electrolytic capacitances 180 and 182 will charge as they did when the low intensity mode of operation was selected. Additionally, the trigger 120 volt 60 Hertz signal on the signal line 106 from the distant control box will be 45 cycles long, and 120 volt 60 Hertz voltage will exist on the high signal line 108, causing the charge and discharge timing and control logic module 82 to turn on the high optically controlled switch 86 during the last fifteen cycles of the time in which the low switch 84 is on. Conduction of the high switch 86 for fifteen cycles of the 60 Hertz line source 78 raises the voltage of the main energy storage electrolytic capacitances 202 and 204 to approximately 160 volts each in the polarity provided by the voltage multiplier diodes 206, 208, 210 and 212 and current-limited by the foil-and-film capacitors 214 and 216. The power diodes 218 and 220 isolate the low energy storage electrolytic capacitances 180 and 182 from the main energy storage electrolytic capacitances 202 and 204 whenever the main energy storage capacitances 202 and 204 are at voltages lower than the voltages on the low capacitances 180 and 182.
When high intensity operation is selected, the "kindling" capacitors 154, 158, 162 and 164 and the low electrolytic capacitances 180 and 182 will charge as they did when the low intensity operation was chosen. The trigger 120 volt 60 Hertz signal at the trigger input line 106 will be the same as it was for the low intensity operation, namely, 15 cycles long, and 120 volt 60 Hertz will exist on the high line 108, causing the charge and discharge timing and control logic module 82 to turn on the high optically controlled switch 86 during all forty-five cycles of the available charging time. Using all forty-five cycles for charging the main energy storage electrolytic capacitances raises them to their maximum charged voltage of approximately 270 volts so they can supply the energy for the high intensity flash of 5000 plus or minus 2000 Effective Candella Power. Using the foil-and-film capacitors 214, 216, 192, 194, 174 and 176 conveniently limits the input currents on any cycle of the line source 78 so that surges associated with resistive charging are avoided, and the foil-and-film capacitors accurately convey controlled amounts of charge to be accumulated by the energy storage capacitances 202, 204, 180, 182, 162, 164, 154 and 158.
Because high intensity operation applies approximately maximum rated electrolytic capacitor working voltage during routine operation of the flashlamp system, the electrolytic capacitors will not deform. Overvoltage stress on the electrolytic capacitors is avoided by the threshhold voltage sensor in each of the two power Schmitt triggers 110 and 112. When the threshhold of either of the sensors is exceeded, the associated power Schmitt trigger is activated, which latter then immediately activates the other power Schmitt trigger through the logic module 82. While the Schmitt triggers are conducting and dissipating energy in their load resistances 222 and 224, they also signal the logic module 82 that they are in heavy conduction, and the low and high optically isolated power switches 84 and 86 are held in a nonconducting mode, although trigger signals are allowed to pass to the lamp 140 to enable the lamp 40 to be triggered at the proper times. Surges in line source 78 can be accommodated, and the flashing of lamp 140 can be continued with this arrangement of the Power Schmitt triggers 110 and 112, although the primary function of these Power Schmitt triggers is to safely discharge the main energy storage capacitances 202, 204, 180 and 182 when the line source 78 voltage is removed.
Neon lamps 226 and 228, and their respective ballast resistors 230 and 232 regulate the "kindling" voltage to within the flashlamp 140 manufacturers' specifications and also indicate circuit functioning for rapid and safe maintenance evaluation. Light emitting diodes (not specifically shown) in the control logic module and in the Power Schmitt triggers also indicate circuit functioning for rapid and safe maintenance evaluation.
The optional thermostatically controller heater 102 warms the electrolytic capacitances 202, 204, 180 and 182 when the ambient temperature falls below minus 35° C. (-31° F.). Use of this heater in combination with premium electrolytic capacitors designed for -55° C. operation insures immediate adequate operation of the flasher down to -55° C. The heater is operated by applying the line source 78 voltage to the power supply while providing no trigger voltage pulse at connection 106.
The charge and discharge timing and control logic module 82 and the circuit components may be appropriately chosen to produce a variety of flashlamp controlled discharge optical output waveforms varying from short high instantaneous intensities of high RMS current value to long low instantaneous intensities of low RMS current value. Other arc devices can be similarly controlled in various applications of the present invention. Such applications are not limited to those which require visual detection.
While particular embodiments of the present invention have been shown, it will be understood, of course, that the invention is not limited thereto since modifications may be made by those skilled in the art, particularly in light of the foregoing teachings. It is, therefore, contemplated by the appended claims to cover any such modifications as incorporate those features which come within the true spirit and scope of the invention. | A radiation receiver is disclosed which, with no moving parts, detects both the azimuth and elevation of radiation in a panoramic field external to the receiver. The receiver includes at least one radiation sensitive element and a refractor. The refractor includes a plurality of prisms distributed on the walls of the refractor and forming a distributed focal plane adjacent to the refractor. The radiation sensitive element is located in the depth of field of the focal plane, and the image of at least one portion of the source of radiation is focused by the refractor from the far field of the refractor onto the radiation sensitive element. The disclosed combination reduces the possibility of damage by the radiation to the radiation receiver. | 7 |
FIELD OF THE INVENTION
This invention relates to tank blanketing valves which sense gas pressure in the vapor space of a tank and which maintain the gas pressure within the tank at or above a set point by the addition of an inert gas, as needed.
BACKGROUND OF THE INVENTION
Maintenance of an inert (or protective) gas in the vapor space over a flammable liquid held in a storage tank prevents atmospheric air from entering the tank. This minimizes liquid evaporation and environmental emissions, reduces fire and explosion risks, and also prevents a buildup of vacuum (subatmospheric pressures) in tank vapor space that is in excess of the tank's design capacity. To achieve such maintenance, tank blanketing valve assemblies that incorporate vapor space gas pressure sensing and regulating means have come into widespread use. Such a valve assembly is functionally associated with a top portion of a storage tank along with an independently functioning emergency pressure vent and an independently functioning conservation vent. The latter vent may be in association with a flame arrestor.
Tank blanketing valve assemblies often incorporate a main valve and a cooperating pilot valve operating in tandem. In such an assembly, a sensed pressure change in the tank gas causes a responsive movement in the pilot valve that opens the main valve and allows inert gas to flow into the tank.
Prior art tank blanketing valves suffer from various problems. One problem is that in an assembled tank blanketing valve, it was not previously possible to conveniently adjust the internal operation or position of pilot valve functional components. The pilot valve and the main valve components had to be precisely machined to achieve a predetermined positional relationship between components. Upon assembly, even slight variations in machining tolerances, operating conditions or even environmental conditions could change the desired operating characteristics of the assembled tank blanketing valve. There was no known way to adjust the positioning of the internal functional components of the pilot valve relative to one another from an external location after valve assembly.
Another problem is that an O-ring seal associated with the pilot valve assembly located entirely within the assembled tank blanketing valve but adjacent to the main valve dome chamber had a tendency to unseat during main valve operation. The unseating occurs as a result of pressure differentials that act upon the seal. The unseating results in excessive inert gas leakage. Reseating of this O-ring can only be accomplished by dismantling the entire tank blanketing valve.
The present invention provides a tank blanketing valve structure which overcomes the foregoing problems.
SUMMARY OF THE INVENTION
More particularly, this invention relates to a new, improved and very useful tank blanketing valve assembly which incorporates a main valve assembly and a cooperating main-valve actuating pilot valve assembly, and wherein the position of certain components of the pilot valve assembly are externally adjustable. The invention also relates to the improved pilot valve assembly.
The improved pilot valve assembly employs an improved combination of an elongated poppet which slidably and longitudinally moves in a cylinder defined by upper and lower cylindrical plug means. The lower plug means is longitudinally adjustable in the pilot valve assembly.
Thus, by the present invention, the slight relative size changes characteristically occurring in pilot valve components, which can result from various causes, for example, machining tolerances, blanketing valve operating conditions, environmental conditions, or the like, can be adjusted and compensated for even after valve assembly. Such adjustability is achieved without adversely affecting the intended functioning of the valve or its components, such as the functioning of gas conducting channels extending in, through and/or adjacent to either the pilot valve poppet body, or of the upper and the lower plug means. The pilot valve is balanced due to the presence of the same top and bottom sealing means. Inlet pressure thus does not effect pilot valve function.
Preferably, the tank blanketing valve assembly of this invention also includes a pressure relief port (or orifice) that is precisely located in the lower plug means so as to be adjacent to an O-ring seal that is supported by the lower plug means. This O-ring seal functions to help seal the channel connecting the pilot valve assembly with the dome chamber of the main valve assembly when the poppet of the pilot valve assembly is in its valve closed position. When the poppet is in its valve open position, however, this port prevents gas pressure changes of the type which occur in the region of this O-ring during operation of the main valve from unseating the O-ring.
Preferably, the tank blanketing valve assembly of this invention also includes an internal pilot valve gas exhaust channel, thereby avoiding the need for external gas conduit means.
The invention further relates to a new and improved combination of a subassembly for a pilot valve of a tank blanketing valve assembly that also employs a coacting and cooperating main valve subassembly as well
sure sensing means to which the pilot valve subassembly is responsive. The pilot valve subassembly incorporates a coacting combination of valve body, upper plug, adjustable lower plug, elongated poppet which slidably and longitudinally moves in a cylinder defined by the upper and lower plugs, and a pin-guided biasing spring for the poppet.
The tank blanketing valve assembly of the invention overcomes the foregoing disadvantages of prior art tank blanketing valve assemblies having a fixed interrelationship between the pilot valve components. A tank blanketing valve with a pilot valve assembly wherein upper and lower cylindrical plugs define the poppet cylinder was not known to the prior art so far as now known.
Other and further objects, aims, purposes, features, advantages, embodiments and the like will become apparent to those skilled in the art from the present description, the accompanying drawings and the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
In the drawings:
FIG. 1 is side elevational view showing an embodiment of a tank blanketing valve of this invention employed in a typical tank installation;
FIG. 2 is a vertical sectional view taken through the center of the tank blanketing valve of FIG. 1, the tank blanketing valve being shown in its closed position;
FIG. 3 is a horizontal sectional view taken along the line III--III of FIG. 2;
FIG. 4 is an enlarged fragmentary view of the pilot valve of FIG. 2 showing the pilot valve in its closed position with the popper rotated 90° relative to its position in FIG. 1;
FIG. 5 is an enlarged fragmentary view similar to FIG. 4, but with the tank pressure sensing conduit removed, and showing the pilot valve in its open position; and
FIG. 6 is an exploded perspective view of the poppet/pin/spring plug subassembly employed in the pilot valve assembly utilized in the embodiment shown in FIGS. 2 through 5 but with O-rings removed.
DETAILED DESCRIPTION
Referring to FIGS. 1 through 6, there is seen one illustrative embodiment 10 of a tank blanketing valve of this invention. A typical installation for valve 10 is illustrated in FIG. 1 where valve 10 is operably and functionally connected with a top portion or dome 12 of a storage tank 11. The dome 12 is shown independently and separately associated with a conventional conservation vent 13 and with a conventional emergency relief vent 14.
The conservation vent 13 is sized to take care of overpressure and Vacuum conditions brought about by pumping and thermal conditions or certain equipment failures. The vent 13 is associated with a pressure pallet (not detailed) whose pressure setting is set at a slightly higher setting than the blanketing pressure in the vapor space beneath dome 12 in the tank 11, but which setting is below the maximum pressure that the tank 11 is designed to withstand. Similarly, the vent 13 is also associated with a vacuum pallet (not shown) which is set to open to atmospheric air when a higher vacuum pressure (i.e., a lower subatmospheric or reduced pressure) occurs in tank 11 than is reached in normal operating conditions, such setting being a reduced pressure that is above the negative pressure that the tank 11 is designed to withstand.
The vent 13 is here illustratively connected in series with a conventional flame arrester 16 that provides additional protection in the event of inert gas failure in tank 11.
As shown in FIG. 1, the tank blanketing valve 10 is illustratively being used in a tank blanketing gas application to regulate the pressure of an inert gas, such as nitrogen or the like, existing on the top surface of a liquid (not indicated) that is stored in tank 11. The valve 10 senses the pressure of the tank gas blanket and opens to admit more inert gas when the gas pressure in tank 11 drops below a set pressure (as when the liquid level drops). The valve 10 closes and stops gas admission when gas pressure in tank 11 builds back above the set pressure.
As shown, for example, in FIG. 2, the tank blanketing valve 10 comprises two separate valves cooperatively operating in tandem, a pilot valve 17 which is controlled by the tank 11 sensed pressure and a main valve 18 whose opening and closing is controlled by the pilot valve 17. The main valve 18 when open provides flow of inert gas into tank 11 from an inert gas supply (not shown). The pilot valve 17 responds to pressure changes sensed by a pressure sensor 19 resulting in movement of a poppet 21 in valve 17. Movement of poppet 21 causes a piston 22 in main valve 18 to move and resultingly admit inert gas into tank 11. Valve 10 is arranged and adjusted so that the valves 17 and 18 and pressure sensor 19 operate responsively to a predetermined set pressure that is itself dependent upon the pressure differential existing at any given time between sensed atmospheric pressure and sensed internal tank (head) pressure.
The set pressure of valve 10 can be regarded as the pressure at which the main valve 18 opens. In general, the pilot valve 17 begins to leak inert gas at a pressure slightly above the set pressure (or set point). As the pressure thereafter decreases to the set point,
the pilot valve 17 opens fully, so that the pressure holding the main valve in a closed position drops and allows the main valve to open. Inert gas flow into the tank 11 from valve 18 raises the tank inert gas pressure to a point which causes each of the main valve 18 and the pilot valve 17 to reseal into their respective closed configurations. The poppet 21 in combination with other pilot valve components provides for pressure balanced operation that achieves a dependable, consistent opening pressure over the allowable range of inlet inert gas supply pressures.
Three external connecting conduits are required for operation of valve 10. One conduit 23 extends between dome 12 and pilot valve 17 to provide a source for the gas pressure in tank 11 that is sensed and compared by valve 10 to atmospheric air pressure. A second conduit 24 extends from the inert gas supply and connects with the inlet channel 26 in the main valve 18. A third conduit 27 connects the outlet channel 28 of the main valve 18 with tank 11.
The body 29 of main valve 18 is also provided with an external conduit 31 (see FIG. 3) which extends from inlet channel 26 to a small orifice 32 that opens into the dome chamber 33 of the main valve 18 whereby inert gas can bleed into the dome chamber 33 from inlet channel 26. Conduit 31 is preferably functionally associated with a conventional in-line filter 35 (not detailed). Preferably, inert gas entering conduit 31 and valve 18 passes through a conventional screen assembly 40 that is nestably received in a neck region of inlet channel 26. Alternatively, inert gas can be fed to orifice 32 through an internal channel (not shown) provided in the valve body 29, or through a channel and orifice in piston 22 (not shown).
The conduit 23 is preferably connected to the dome 12 at a distance sufficiently spaced from the connection location of conduit 27 so that an inert gas flow stream entering tank 11 from conduit 27 will not effect the gas pressure in conduit 23. Conduit 23 interconnects with channel 34 in the body 36 of pilot valve 17. The gas pressure in tank 11 is thus conveyed to the chamber 37 of pressure sensor 19. Chamber 37 is associated with the underside of the diaphragm 38 in pressure sensor 19.
As shown, for example, in FIGS. 2 and 4, the pressure sensor 19 is itself of the diaphragm type broadly previously known in the art and employs a case 66 defined by a saucer-configured lower case 66A and a rimmating, inverted (relative to case 66A), saucer-configured upper case 66B. Case 66A is mounted centrally and horizontally against the flattened upper face of pilot valve body 36 by means of hex screws 67 and associated lock washers 68 with a gasket 69 positioned between case 66A and body 36. Case 66B is mounted centrally and horizontally against the flattened base 71 of an air intake and set point adjustment subassembly 72 by means of hex screws 73 and associated lock washers 74.
In the air intake and set point adjustment subassembly 72, the number of independent cooperating components is preferably (as shown) minimized to reduce parts and assembly costs. The base 71 is integrally formed and connected with a spring guide 76. A coiled compression set spring (preferably stainless steel) 43 is located in spring guide 76 and is yieldingly compressed between a lower anchor 79 and an upper anchor 81. The upper anchor 81 is slidably and longitudinally movable within spring guide 76. An elongated set screw 82 threadably extends through the upper outward integral neck 83 of spring guide 76 so that the forward inner end of set screw 82 abuts against, but is rotatable relative to, the back face of upper anchor 81. For fixing the position of set screw 82 relative to neck 83, the rearward portion of set screw 82 is threadably associated with a jam nut 84 and a lock washer 86 that circumferentially extends interveningly between nut 84 and the top flat face of neck 83. The circumferential outside of neck 83 is threadably associated with a removable protective cap 87. The spring guide 76 is integrally formed with an elbow-type fitting 88 that is preferably welded to a conventional screen 91 assembly.
In case 66, upper case 66B is connected along its perimeter to lower case 66A by a plurality of circumferentially spaced interconnected hex screws 92 and jam nuts 93 with lock washers 94. The perimeter of diaphragm 38 is associated between the upper case 66B and lower case 66A with an intervening gasket 96. The mid-central region of a pressure-responsive diaphragm 38 whose periphery is held between the joining perimeter of upper case 66B and lower case 66A as shown is joined on each side thereof by one member of a pair of rigid plates 97. The lower anchor 79 is threadably secured to the center of plates 97 by a hex screw 98 that extends through the plates 97 and this combination is provided with a lock washer 99. The head of hex screw 98 serves as a stop for the axially upwardly projecting stem 46 of poppet 21. Case 66 is thus divided into two separate chambers, an upper chamber 39 which is at atmospheric pressure and charged with air, and the lower chamber 37 which is at tank pressure and charged with inert gas from tank 11.
In effect, pressure in tank 11 exerts a force on the lower side of diaphragm 38 while atmospheric pressure (which is conveyed to the opposing chamber 39 through fitting 88) plus the force of the adjustable spring 43 exert a downward force on diaphragm 38 upon the top side thereof. When the pressure in tank 11 drops below the set pressure (which is fixed by the compression setting chosen for spring 43), then the head of hex screw 98 (see FIG. 4, for example) that is abuttingly engaged with the longitudinally projecting stem 46 of the poppet 21 pushes downwardly on the end of stem 46. This causes poppet 21 to move downwardly, and moves poppet 21 from an upper valve closed position as shown, for example, in FIG. 4 to a lower valve open position as shown, for example, in FIG. 5, thereby relieving the pressure in chamber 33 and opening the pilot valve 17.
As shown, for example, in FIG. 6, the poppet 21 is generally circular in cross-section and has a characteristic barrel-like profile (medially thickened exterior mid-region 61) when viewed in side elevation. Opposite ends 56 and 57 of poppet 21 are circumferentially outwardly flanged. A circumferentially extending longitudinally broadened groove 53 is defined around its mid-region. The stem 46 axially and outwardly projects integrally from its upper opposite end 56. From its lower opposite end 57, a channel 54 axially extends upwardly through the poppet 21 to a terminal location that is in axially spaced relationship to the upper opposite end 56.
Radially extending channels 58 (see FIGS. 4 and 5) and 59 extend through the side walls thus defined in poppet 21 and intersect channel 54 in each of the two medial poppet regions 62 and 63 (see FIG. 6) of reduced diameter, such regions being located between each opposite end 56 and 57 and the mid-region 61. The respective outside diameter of each of the flanges 56A and 57A at respective opposite ends 56 and 57, and also of the circumferential ridges on each longitudinal side of the groove 53 in mid-region 61, is such that the poppet 21 is positioned and guided for longitudinal slidable movements in the cylindrical chamber 47 defined by coaxial bores 47A and 47B in the body 36 of pilot valve 17 that are associated respectively with the upper plug 107 and the lower plug 117, as further described below.
The stem 46 extends upwardly through valve body 36 and upper cylindrical plug 107, and into the chamber 37 through an aperture 125 in case 66A, so that the forward end of stem 46 abuts against the head of hex screw 98. Stem 46 is retained in engagement with the head of hex screw 98 by the coiled compression spring 52 which axially extends between a pocket 124 axially defined in the bottom of the bore 47B in lower plug 117 and a shoulder 64 provided in channel 54 that is inset from the widened open end region of channel 54.
As shown, for example, in FIG. 6, the poppet 21 is provided with an O-ring receiving circumferential groove 101 in the upper ridge 102 (that is, the ridge defining the longitudinal side of the groove 53 in poppet 21 which ridge is adjacent the poppet upper opposite end 56), and this groove 101 is provided with an O-ring 103 (as shown, for example, in FIGS. 4 and 5).
The valve body 36 is provided with a medial bore 104 that extends perpendicularly therethrough relative to the mid-region of lower case 66A. The upper end region of bore 104 is provided with a square profiled shoulder 106 at its upper end. The lower end region 105 of bore 104 is circumferentially internally threaded. Into the upper end region of bore 104 the upper cylindrical plug 107 is slidably engaged. The upper end of upper plug 107 is provided with a circumferentially extending flange 108 which is nestably received in the shoulder 106 and which limits downward travel of upper plug 107. After insertion, the upper plug 107 is held in place by the associated overlying lower case 66A.
Downwardly from, but adjacent to, flange 108, the cylindrical outer surface of the upper plug 107 is provided with a circumferentially extending groove 109 into which an O-ring seal 111 (see FIGS. 4 or 5) is seated. In a medial outer surface location along the length of upper plug 107, a circumferentially extending channel 112 is preferably provided. Channel 112 is longitudinally adjacent to the groove 109. Extending axially upwardly in upper plug 107 from its lower end is a bore 47A which terminates in spaced relationship to the upper end of upper plug 107. The inner upper end of bore 47A in upper plug 107 is provided with an axially extending smaller aperture or channel 116 whose diameter is adapted to receive slidably therein the stem 46 of poppet 21. In the location between the longitudinally medial region occupied by channel 112 and the lower end of upper plug 107, a circumferentially extending groove 129 is defined in the circumferential wall of bore 104 into which an O-ring seal 131 is seated. The O-ring seals 111 and 131 function to isolate and place the channel 112 in a gas-tight relationship relative to upper plug 107 and body 36. Bore 47A has a diameter that is adapted to slidably receive the upper portion of the body of poppet 21. A channel 116A extends diametrically through the side walls of upper plug 107 in the region of the circumferential channel 112. Channel 116A intersects (connects with) bore 47A.
Into the lower end region of bore 104, the lower cylindrical plug 117 is slidably engaged. A lower end region of lower plug 117 is exteriorly circumferentially threaded and adapted for engagement with a threaded lower end region 105 of bore 104. The lower end of lower plug 117 is provided with a diametrically extending groove 118 for engagement with a screw driver or like tool (not shown) for lower plug 117 positioning and adjustment purposes. The protruding portion of lower plug 117 relative to the lower end of body 36 is preferably provided with a lock nut 120 for fixing a desired set position for lower plug 117. Lock nut 120 is preferably fixed to lower plug 117 at assembly to allow for reassembly in the field. The upper interior end of lower plug 117 terminates in axially spaced, adjacent relationship to the lower interior end of upper plug 107. When the upper plug 107 and the lower plug 117 are assembled in the bore 104 of body 36, a circumferentially extending peripherally located cavity 137 is defined therebetween that is contiguous with bore 104. The terminal position of the upper end of lower plug 117 is determined by the extent to which the threaded portion of lower plug 117 is threadably engaged with the threaded terminal portion 105 of the bore 104.
Upwardly from, but longitudinally adjacent to, the threaded lower portion of lower plug 117, a circumferentially extending groove 119 is provided in lower plug 117 into which an O-ring seal 121 is seated. Upwardly from, but longitudinally adjacent to, the groove 119, a circumferentially extending channel 122 is provided in the outer circumferential side wall of lower plug 117. Extending axially downwardly from the inner end of lower plug 117 is a bore 47B which terminates in longitudinally spaced relationship to the lower end of lower plug 117. The inner lower end of bore 47B is provided with a smaller blind aperture or pocket 124 whose diameter is adapted to slidably receive therein the head of a headed pin 126 whose shank is circumferentially associated with the coiled spring 52. In the location between the medial region occupied by channel 122 and the upper end of lower plug 117, a circumferentially extending groove 132 is defined in the circumferential wall of bore 104 into which an O-ring seal 133 is seated. The O-ring seals 121 and 133 function to isolate and place the channel 122 in a gas-tight relationship relative to lower plug 117 and body 36. Bore 47B has a diameter that is adapted to slidably receive the lower portion of the body of poppet 21. A channel 136 extends diametrically through lower plug 117 in the region of the circumferential channel 122. Channel 136 intersects (connects with) bore 47B.
Communicating with channel 112 in upper plug 107 is a transverse channel 134 that is defined in body 36. Communicating with channel 122 in lower plug 117 is a transverse channel 136 that is also defined in the side wall of body 36. Communicating with the cavity 137 that is located between the lower end of upper plug 107 and the upper end of lower plug 117 is a transverse channel 138 that is likewise defined in the side wall of body 36. Each of the channels 134 and 136 in the side wall of body 36 communicates with a longitudinally oriented circular groove or channel 135 formed in the outer surface of the side wall of body 36. Channel 138 extends through the side wall of body 36 and communicates with dome chamber 33 in body 29 respective. The mouths of the channels 134 and 136 are thus interconnected together by a generally circumferentially defined channel 135 (not detailed) defined in the adjacent side wall of body 36. The mouth of the channel 138 is provided with an outstanding shoulder 139 that extends circumferentially thereabout.
The body 29 of the main valve 18 is adapted to engage abuttingly over the shoulder 139 and the adjacent side wall portions of the pilot valve body 36 that extend about the mouths of the channels 134 and 136. For sealing and isolation purposes, the mouths of the channels 134, 135, 136 and 138 are provided with O-ring seals 141 and 142 which are seated in mating circular grooves 143 and 144 respective defined in valve body 29.
The mouth of channel 138 effectively helps define the so-called dome chamber 33 of the main valve 18. Thus, the mouth of channel 138 is generally coaxial with a bore or channel 146 in body 29. Channel 146 extends generally perpendicularly to the bore 104 in body 36 and channel 146 extends through the body 29. The piston 22 is adapted for axial reciprocal sliding movements in bore 146. The forward end of piston 22 has axially defined therein a pocket channel 147. A coiled compression spring 148 (preferably stainless steel) is inserted into and supported by the side walls of channel 147. One end of spring 148 rests against the interior end of channel 147 in piston 22 while the other end of spring 148 rests against the entrance lip of channel 138 in body 36. A rear portion of channel 146 has an aperture 145 (see FIG. 2) that interconnects with the inert gas outlet channel 28. The adjacent rear end wall of channel 146 interconnects with the inert gas inlet channel 26.
In order to provide a sealed arrangement to isolate dome chamber 33 from inset channel 26, the side of piston 22 is provided with a circumferential groove 149 in which an O-ring seal 151 is seated. Another O-ring seal 152 that extends circumferentially about the terminal end of piston 22. O-ring seal 152 is retained in position at the end of piston 22 by a plate 154. The O-ring 152 is thus effective to seal gas flow between conduit 24 and conduit 27. A screw 156 retains a flow plug 155 at the end of the piston 22. In combination with lock washer 157, the hex screw 156 holds the O-ring 152, the cap plate 154 and the flow plug 155. Thus, when the piston 22 is biased into a normally rearward closed position in bore 146 (as shown in FIG. 2) by spring 148, both the outlet channel 28 and the inlet channel 26 are in a sealed shut configuration.
In the blanketing valve 10 closed position that is shown for example in FIGS. 2 and 4, the poppet 21 is in its upward closed position and the piston 22 is in its rearward closed position. Relative to poppet 21, the O-ring seal 103 is in sealed engagement with the lower edge of bore 47A and O-ring seal 127 is in sealed engagement with the lower ridge edge of the groove 53 of poppet 21. An elongated chamber 158 is radially located between poppet 21 and bore 47A in poppet region 62, and an elongated chamber 159 is radially located between poppet 21 and bore 47B in poppet region 63. Chambers 158 and 159 are in continuous communication with each other through channels 54, 58 and 59 in poppet 21. A negligible amount of gas leakage at tank pressure can occur from chamber 37 down along the sides of stem 46 into chamber 158. Gas enters the dome chamber 33 through conduit 31 and orifice 32 and the pressure in the dome chamber 33 is substantially at the supply pressure of the gas in conduit 24.
Opening of the pilot valve 17 is achieved through only a small axial movement of poppet 21 downwardly from its normally closed position as shown in FIG. 4. This axial poppet 21 movement occurs in the elongated, generally cylindrical chamber 47 (defined by coaxial bores 47A and 47B) in the respective plugs 107 and 117). Poppet 21 thus moves to its pilot valve open position as shown in FIG. 5. Such an opening of pilot valve 17 as shown in FIG. 5 vacates the gas from the volume of dome chamber 33 as shown by the arrows 160 in FIG. 5 by allowing gas flow past O-rings 103 and 127 into channels 134 and 136 and out through the pilot exhaust channel 169 in body 29 into outlet conduit 27 (see FIG. 2). Direction of gas flow in channels 134 and 136 is shown by arrows 161 and 162 respectively and in channel 138 by the arrows 160. This passage, and the gas pressure changes in the dome chamber 33, cause the piston 22 of main valve 18 to open, thereby allowing inert gas flow into the tank 11 through conduits 24 and 27.
Thus, the piston 22 is normally held closed when the pressure in dome chamber 33 equals the inlet pressure in conduit 24 because there is a larger area of piston 22 exposed to the dome chamber 33 pressure than the area of piston 27 that is exposed to the inlet pressure in conduit 24. A significant drop in the pressure in dome chamber 33, however, allows the piston 22 to be pushed towards the dome chamber 33 and into a main valve open configuration open by the inert gas inlet pressure in conduit 24.
When inert gas flow into the tank 11 raises the tank 11 pressure above the set pressure, then the diaphragm 38 is pushed up, thereby allowing the poppet 21 to raise up responsive to the expansive force of the spring 52 under the poppet 21 until the poppet 21 reseals at O-ring seals 103 and 127. When the poppet 21 reseals, the pressure in dome chamber 33 builds back up to the inlet pressure in conduit 24 thereby pushing the piston 22 into its fully closed position shown in FIGS. 2 and 4 and shutting off flow of inert gas into tank 11.
Also, those skilled in the art will appreciate that various locations and component arrangements can be utilized for the O-ring seals employed for sealing the poppet 21 relative to the channel 137. However, the arrangement shown in FIGS. 2-6 is presently preferred. With such an arrangement, it is preferred to provide a pressure equalization orifice 170 (see, for example, FIG. 6) for the lower O-ring seal 127. Orifice 170 extends radially through the outer wall of lower plug 117 into connecting relationship with the groove 128. The orifice 170 functions to prevent gas pressure changes of the type which occur in the region of the O-ring seal 127 when the poppet 21 moves to its valve open position from unseating O-ring seal 127.
Thus, in the pilot valve assembly of this invention, a valve body is employed having a bore defined therethrough. This bore is here regarded for descriptive purposes as having an upper end and an opposite lower end.
First and second cylindrical plug means are inserted into respective said upper and lower ends of the bore. Each plug means is adjacent to a different one of the bore opposite ends. The second plug means includes thread means engagable with a threaded portion of the valve body bore whereby the second plug means is longitudinally adjustably positionable in the bore. The first and the second plug means together cooperate to define coaxial portions of a longitudinally extending, medial cylindrical cavity with an adjoining circumferential peripheral channel located between longitudinally adjacent, spaced interior end portions of the first and the second plug means.
Elongated poppet means is included which is longitudinally slidably positioned in the cylindrical cavity for movement between an upper valve closed position and a lower valve open position. This poppet means has an upper end located in the first plug means and an opposite lower end located in the second plug means, and external circumferential poppet side walls.
An upwardly projecting stem at the poppet upper end is provided.
The poppet includes a pair of circumferentially extending poppet chambers. Each chamber is defined along and in a different portion of the poppet side walls. Each one of these poppet chambers radially adjoins the adjacent cylindrical cavity and is longitudinally adjacent to a different respective one of the opposite bore ends. Internal conduit means in the poppet interconnects each one of the poppet chamber means.
The poppet side walls have longitudinally adjacent circumferential upper and lower mid-region portions that radially outwardly extend and that cooperate with O-ring sealing means. Thus, individual sealing engagement of these mid-region portions circumferentially about the respective upper and lower inner end portions of the first and the second plug means is achieved when the poppet means is in its upper valve closed position.
Spring means 52 for yieldingly biasing the poppet 21 in the closed position is provided. Thus, when the poppet 21 is in the upper valve closed position, then each of the two poppet chambers is sealed from the peripheral channel. However, when the poppet means is in its lower valve open position, then each of the two poppet chambers communicates with the peripheral channel.
Preferably, in the inventive pilot valve assembly, each of the upper and the lower plug means has defined therein a circumferentially extending plug channel in a longitudinal mid-region thereof so as to be located in cooperative, radially adjacent relationship to adjacent portions of the valve body bore. Also, at least one radially extending plug channel extends from said circumferentially extending plug channel through each of said plug means to the radially adjacent one of said poppet channels. The valve body also has defined therein channel means which interconnect together each of the two plug channels. Further interconnected by channel means are the plug channels with an output channel of the main valve assembly. Thus, when said poppet means is in its lower valve open position, gas can pass from the peripheral channel to the output channel.
Preferably, in the inventive pilot valve assembly, the sealing engagement between the upper mid-region portion and the inner end portion of the first plug means is achieved by an upper O-ring sealing means which is received in a circumferential groove defined around an upper mid-region portion. Also, the sealing engagement between the lower mid-region portion and the end portion of the second plug means is achieved by a lower O-ring sealing means which is received in a circumferential groove defined in the second plug means and extending around the cylindrical cavity adjacent to the inner end portion of the second plug means.
Preferably, in the pilot valve assembly of this invention, there is provided a pressure equalization orifice for the lower O-ring sealing means in the second plug means. This orifice preferably extends radially through the second plug means at a longitudinal position therealong that is opposite the circumferential groove therein.
The foregoing description makes use of an illustrative embodiment of this invention, and no limitations upon the present invention are to be implied or inferred therefrom. | An improved valve is provided for blanketing and maintaining the vapor space of a tank with inert gas at a set pressure. The valve is of the type that incorporates a pilot valve that operates in response to sensed tank vapor space gas pressure. The opening and closing of the pilot valve controls the opening and closing of an associated main valve which admits pressurized inert gas into the tank from an inert gas supply to maintain the tank set pressure. The valve permits one to externally adjust internal components of the pilot valve after valve assembly. Also, the valve provides for pressure balanced operation that achieves a consistent opening pressure over the allowable range of inlet gas supply pressures. | 8 |
BACKGROUND OF THE INVENTION
The present invention has particular relation to the apparatus for thickening pulp and paper stock shown in Seifert et al U.S. Pat. No. 4,722,793, issued Feb. 2, 1988 to the assignee of this application. The apparatus disclosed in that patent comprises, as its major component, a pair of liquid-impervious rolls rotatably mounted in spaced relation on substantially horizontal axes. An endless wire is trained around these rolls in wrapping relation with a substantial portion of the surfaces of each thereof, and means are provided for driving one of the rolls to cause this wire to travel around the rolls while cooperating therewith to define a space mounted by the rolls and the opposed upper and lower runs of the wire.
A headbox is mounted in this space and includes an outlet for the pulp suspension to be thickened which is delivered into the space between one of the rolls and the portion of the wire wrapping that roll, whereby this pulp suspension is trapped between the wire and the roll. The rolls are driven at a speed effecting the development of centrifugal force causing liquid to be expressed from between the wire and rolls with the resulting thickening of the pulp carried on the inner surface of the wire, and means are provided to collect and remove this thickened pulp from the space bounded by the wire and rolls.
As is pointed out in the above patent, the apparatus disclosed therein is capable of operating at very much higher speeds than conventional thickening apparatus of the decker type, namely speeds in the range of 1500-4000 feet per minute as compared with decker operation at a linear speed in the range of 200-300 feet per minute. As a result, the capacity of such apparatus, in terms of tons per day of pulp, is correspondingly high, and in developing that apparatus for the marketplace, it was found that special provision should be made for facilitating the collection and removal of the thickened pulp.
Doctor blades of conventional types and mountings, such as are shown in the above patent, were found to have certain disadvantages for this purpose. More specifically, the use of a doctor blade in contact with the surface of the roll was found to be undesirable, for a number of reasons. For one, the resulting friction between the edge of the blade and the roll caused accelerated abrasion damage to both the blade and the surface of the roll, and this abrasion damage was magnified when the apparatus was used, as is conventional, for the thickening of waste paper pulp stock which had been only roughly screened and therefore contained many metal and other hard contaminant particles such as paperclips and staples.
Another problem appeared when a conventionally pressure loaded doctor blade was used in conjunction with the standard practice of utilizing means for reciprocating the blade longitudinally of the roll. It developed in the course of experimental use that over a relatively short period, fibers began to build up on the leading edge of the doctor blade until enough fiber had accumulated to force the blade so far away from the roll as to lose its doctoring effect. It therefore became clear that a new doctoring technique was needed.
SUMMARY OF THE INVENTION
In accordance with the invention, it was discovered that these problems could be successfully solved by employing a doctor blade of substantially heavier proportions than blades of the conventional type, and by supporting this blade with its working edge in close but spaced relation with the roll surface, e.g. with the space between the blade edge and the roll being in the range of 0.010 to 0.100 inch. As is explained in detail below in connection with the illustrated preferred embodiment of the invention, this novel non-contacting doctor arrangement will effect substantially complete removal of the thickened pulp from the bare surface of the roll, and if any pulp should move past it and remain on the roll, will promptly be remixed with partially dewatered pulp in such manner that it will be removed from the roll on its next movement past the doctor blade.
As noted above, the pulp stock with which this type of apparatus is commonly used can be expected to contain fairly large size contaminant materials, of which paperclips and staples offer the most difficulty because of their tendency to catch on the working edge of a doctor blade which is not in contact with the associated roll. In the practice of the invention, this difficulty is overcome by providing the non-contacting doctor blade with sufficient rigidity, and also by periodically moving the working edge of the blade with respect to the roll surface, and especially by temporary movement of the blade edge further away from the roll surface. It has been found in test operation that combination of this movement of the doctor blade in conjunction with the movement of the thickened pulp therepast will effectively dislodge any paperclip type of contaminant material from the blade, and such contaminants are readily removed during subsequent screening operations.
Other advantages of the invention will be apparent from or pointed out in the course of the Description of the Preferred Embodiment of the Invention which follows.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a somewhat diagrammatic side view, partly in section, of thickening apparatus with which the present invention is used;
FIG. 2 is a somewhat diagrammatic isometric view illustrating the structural arrangement of the doctor blade shown in FIG. 1;
FIG. 3 is a fragmentary isometric view further illustrating the operation of the doctor blade shown in FIGS. 1-2; and
FIG. 4 is an enlarged fragmentary view illustrating a modified mounting for the doctor blade shown in FIGS. 1-3.
DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 illustrates the principal structure of the thickening apparatus described and claimed in U.S. Pat. No. 4,722,793. It includes a relatively simple frame comprising two columns 10 and 11 on each side connected by side beams 11 and suitable cross braces 13. The two large rolls 20 and 22 which are the major operating elements of this apparatus are mounted adjacent opposite ends of the frame, the roll 22 being shown as mounted by pillow block bearings 23 on the tops of columns 10 and 11. This roll 22 is a driven roll, through the belt drive indicated generally at 24 by a motor 25 mounted on the cross brace 13 between the columns 10 and 11. The rolls 20 and 22 should have liquid-impervious outer surfaces, but preferably the surface of roll 20 should be grooved, as described in the above patent.
An endless loop of woven foraminous "wire" belt 30 is trained around the rolls 20 and 22 and defines therewith a space in which the other operating parts of the apparatus are located. Preferably the wire 30 will consist of any plastic material currently used for paper machine wires, e.g. polyester. Roll 20 has an adjustable mounting on the frame which includes means for tensioning the wire, each of the journals of the roll 20 being mounted by a pillow block 31 on a base 33 which is in turn mounted for sliding movement on the side beam 12. Means such as a pair of jack screws 35 connected between bases 33 and the adjacent columns 10 cause and control this movement to effect corresponding control of the tension in wire 30.
A headbox 40 is mounted on the same base members 33 as the roll 20 so that it maintains a fixed spacing with respect to roll 20. This headbox is shown as of any open type including lower and upper walls 41 and 42 which extend upwardly to define a spout through which stock is discharged into the wedge zone 44 defined by the upper run of wire 30 approaching roll 20 and the surface of the roll itself. The stock to be thickened is fed to the headbox by any convenient feed line (not shown) from the usual stock supply pump (not shown).
At the other end of the space defined by the upper and lower runs of the wire 30 and the rolls 20 and 22 is a trough 50 having a screw conveyor 51 mounted in the bottom thereof for receiving thickened pulp from the surface of roll 22 in the wedge zone 52 defined by the roll surface and the upper run of wire 30 leaving this roll. A doctor blade 55 bridges the space between the bare surface of roll 22 and the upstream wall 56 of trough 50 to transfer the thickened pulp from the surface of roll 22 to trough 50, and the screw 51 forces the accumulated pulp to a chute (not shown) at the back of the machine which leads to the next station in the system.
Details of the structure and mode of operation of the doctor blade 55 are illustrated in FIGS. 2-4. The blade 55 is shown as a rigid board or plate like member which is as long as the roll 22 and of sufficient width to extend from the bare surface of roll 22 into overhanging relation with the top of trough wall 56. The thickness of doctor blade 55 depends upon its constituent material and should be sufficient to maintain the blade rigid; for example, a thickness of the order of 3/4 inch has been found satisfactory with a blade 55 fabricated of Formica material and approximately 5 inches in width.
A steel blade 55 could be of comparable rigidity with a lesser thickness, e.g. 1/2 inch and a relatively thin and flexible blade could be used if it is mounted on a rigid support or otherwise reinforced. With the doctor blade 55 of the illustrated thickness, it is provided with a relatively wide angled working edge 60 formed by grinding a beveled surface 61 along its upstream side, and an angle in the range of 30°-60° between this surface 61 and the upper surface 62 of the blade may be used.
A blade in the sharper portion of this range has a wider range of adjustment with respect to the angle defined by its upper surface 62 and a tangent 63 to the closest portion of the roll surface. It also facilitates maintaining the desirable greater clearance between tangent 63 and the trailing edge 64 of beveled surface 61 than the minimum clearance between the leading edge 60 and the roll face at tangent 63.
The blade 55 can be mounted in a variety of ways, but preferred results have been obtained in test operation with a mounting which provides for rocking movement between an operating position shown in full lines in FIG. 2 and a raised position shown in broken lines in FIG. 2, as further explained below. For example, as illustrated in FIG. 3, the doctor blade 55 may be provided at each end with a shaft 65 having its outer end supported for rocking movement in an assembly 66 which is in turn mounted in any suitable way on a portion 67 of the main frame 10.
The purpose and function of the assembly 66 is to rock the doctor blade 55 between its two positions illustrated in FIG. 2. Satisfactory results have been obtained utilizing as the assembly 66 a commercial product marketed as "Parker HydroPower Rack & Pinion Rotary Actuator" by Parker Hanifin Corp., Rotary Actuator Division. As illustrated in FIG. 3, this assembly 66 includes a rack 70 which acts as the reciprocating piston of a double acting fluid pressure cylinder and has its teeth 71 meshing with a pinion 72 secured to the adjacent shaft 65.
A line 73 supplies operating fluid to the assembly 66 by way of a timer-controlled valve 75 which can be set to operate the assembly 66 at desired periodic intervals. Thus for each double stroke of the piston 70, the doctor blade 55 will rotate out of and back to its operating full line position as shown in FIG. 2, and it has been found advantageous to cause this action at intervals of the order of 10 minutes for a period of a few seconds, e.g. five or less during which any material which may have "stapled" over the blade edge will be carried away. Alternatively, the mountings for shafts 65 could be changed so that the blade 55 reciprocates lengthwise of roll 22 or moves back and forth linearly with respect to roll 22, as illustrated in FIG. 4. A combination of mountings can also be used to cause the blade to reciprocate lengthwise of roll 22 as well as back and forth with respect thereto.
In the operation of this apparatus, the pulp suspension to be thickened is initially supplied to the space between the wire 30 and roll 20 from the headbox 40, and it is desired that the wire tension be sufficiently low as to encourage the entry of a substantial volume of pulp suspension to enter the space between the wire and the surface of roll 20. This result is aided if the surface of the roll 20 is grooved, as explained in the above-noted U.S. Pat. No. 4,722,793, but preferred results are obtained if the roll 22 has a smoothly imperforate surface.
As is described in U.S. Pat. No. 4,722,793, the primary action of the wire is to serve as a filter medium that holds the fiber on its inner surface against the action of centrifugal force, which is the major factor causing dewatering of the retained pulp at the contemplated wire speeds in the range of 3,000 or more feet per minute. The white water expressed in this manner through the wire is initially received in a trough 80 which extends under both of rolls 20 and 22 and is provided with a drain outlet 81. A hood 82 is mounted above the apparatus as a whole, and it fits into the top of the trough 80 so that any water hitting the inner surface of this hood will drip therefrom into the trough 80.
With the roll 20 having a grooved or otherwise indented surface, the pulp which is thickened as it travels around this roll with the wire will remain as a relatively smooth layer 85 on the wire and travel thereon to the roll 22. Additional stock to be thickened may be applied thereon at the wedge zone 86 defined by the lower run of the wire and the roll 22, as indicated by the secondary headbox 88 and as described in U.S. Pat. No. 4,722,793.
The function of the doctor blade 55 is to remove from the surface of roll 22 the layer 90 of pulp which has been thickened during its travel around this roll, and to transfer that pulp to the trough 50. It has been found that this removal and transfer is effected smoothly, and while avoiding the possibility of abrasion damage to the roll surface, by having the working edge of the doctor blade 55 spaced out of contact with the roll surface rather than pressure loaded against this surface as in the conventional practice, and by oscillating the blade 55 as described.
More specifically, the first layer of pulp on the bare surface of roll 22 will be of a thickness in the range of 0.009 to 0.062 inch, and although the blade edge 60 is spaced out of contact with the roll surface, if it intercepts any of the thickness of this pulp layer, the remainder of the layer will tend to lift off the roll surface with the intercepted portion of the layer. In other words, the blade edge 60 does not tend to cleave the layer of pulp on the roll, and whatever pulp lies between edge 60 and the roll surface will tend to cling to and be lifted off with the portion of the layer which is intercepted by blade edge 60.
If, however, any pulp remains on the roll surface, or if the initial layer is thinner than the space between the bare surface of the roll 22 and the blade edge 60, this has no material effect, because the pulp layer will be carried back into the wedge zone 85 where additional pulp entering that wedge zone on the surface of the wire will be laid on top of the layer already on the roll. Thus it will travel around on the roll a second time, or even multiple times, but will ultimately be removed down to the bare roll surface when it accumulates to a sufficient thickness to catch on the blade edge 60.
The operating position of doctor blade 55 shown in full lines in FIG. 2 can be established by initial adjustment of the assembly 66, or by mechanical stops. However this is done, the operating position of the doctor blade 55 should locate its edge 60 in close but spaced relation with the bare surface of roll 22. Test operations have indicated that optimum results are obtained with this position locating the blade edge 60 at a space of 0.010 inch from the bare surface of roll 22, although satisfactory results may be obtained at greater spacings, up to as much as 0.100 inch, as may be determined by the operator in accordance with the type of stock being thickened. The dotted line position of blade 55 in FIG. 2 preferably provides a space of the order of 3/16 inch between edge 60 and the bare surface of roll.
As noted above, it is anticipated that thickeners of the illustrated type will often be used for thickening waste paper stock which has not been sufficiently screened to remove metallic contaminants such as paperclips and staples. If the apparatus is operated with the doctor blade 55 held in fixed position, items of this type will tend to catch on the edge of a doctor blade of conventional relatively small thickness. According to the invention, however, not only is this action inhibited by the relatively wide-angled doctor blade, but if any such objects should catch thereon, they will be dislodged by the periodic movement of the blade so that they are then carried on into the trough 50 by the continuing stream of thickened pulp for removal by subsequent cleaning and/or screening.
While the forms of apparatus herein described constitutes preferred embodiments of the invention, it is to be understood that the invention is not limited to these precise forms of apparatus and that changes may be made therein without departing from the scope of the invention which is defined in the appended claims. | In apparatus for thickening a suspension of pulp material which includes an endless foraminous belt wrapping two spaced horizontally supported rolls, a special doctor mechanism is provided for transferring thickened pulp from the bare surface of the second roll into a trough mounted in the space bounded by the two rolls and the upper and lower runs of the belt. More specifically, the doctor mechanism includes a rigid doctor blade mounted with its working edge in close but spaced relation with the bare surface of the roll to remove pulp therefrom without contact with the roll surface. Provision is also made for periodically oscillating the blade about a horizontal axis to move its working edge away from and back to its closely spaced working relation with the roll. | 3 |
This application is a continuation of U.S. patent application Ser. No. 06/782,745, filed 10/01/85 now abandoned.
CROSS-REFERENCES TO RELATED
Copending U.S. patent application Ser. No. 615,984, filed May 31, 1984, Data Processing System with CPU Register-To-Register Data Transfers Overlapped with Data Transfer To And From Main Storage, now U.S. Pat. 4,630,195, discloses a system in which register-to-register transfers within a CPU are overlapped with data transfers to and from main storage while eliminating or substantially reducing CPU storage cache requirements. Copending patent application Ser. No. 666,789, filed Oct. 31, 1984, Microcode Control of a Parallel Architecture Microprocessor, discloses a microprocessor which repeatedly attempts to execute separate micro-operations within a single microinstruction until all such micro-operations have been successfully completed. Both of the above identified applications are incorporated herein by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a data processing system having virtual memory and more particularly to such a system and methods employed therein for dealing with address translation exceptions in a demand paging system.
2. Description of the Prior Art
A hierarchical memory system may be formed which memory and a low-access-speed high-capacity memory as a secondary store. The main memory is usually an integrated circuit memory and the secondary store or memory is usually a magnetic disk memory. The purpose of the main memory is to provide appropriate transfer rates to and from a processing module, with data and other information being transferred from the secondary store or memory to the main memory as required. A virtual memory system may be created by providing a hierarchical memory system with the ability to automatically transfer requested information from the secondary store to main memory when that information does not reside in main memory at the time of its request. In this manner, the user is not aware of any inherent limitations due to the size of the main memory.
The advantage of a virtual storage implementation is that not all of the stored information, either program or data, needed for the progress of the computation is required to be stored in main memory simultaneously, but that for large periods of time, parts of the stored information may reside in the secondary store. This advantage follows from the fact that main memory is generally more expensive on a per unit or per bit basis than the secondary store. For virtual memory applications, the information is partitioned lB into a number of segments such that, during the progress of the computation, the information of a segment will either be totally present in, or totally absent from, the main or primary store. If all the segments have the same size, they are generally referred to as pages, in which case the primary store is then subdivided into so-called page frames which are units of the store able to contain exactly one page.
In a virtual memory system, demand paging is provided so that computation can proceed at its full rate until an access to an absent page is required. Such a requirement is called a page fault and the computation causing the page fault is halted until the needed page can be brought into the primary store from the secondary store. As new pages are brought into the primary store, some other pages, already present in the primary store when the page fault occurred, must be sent back to the secondary store in order to make room for new pages. The number of pages or page frames provided in primary store for any given program is defined as the program window size.
Different programs, different processes within a given program, or even the same process with different data may require different program window sizes. Some processes may require a few number of instructions which are often recalled and other processes may require long strings of instructions. Some processes may require rather small amounts of data for a time while other processes may require large amounts of data at a given time.
In a computer system which implements storage address translation, the control program must be able to decide which physical page frames are allocated to pages in the large virtual address space. The most efficient means of making this decision is by demand paging. In this scheme, physical page frames are allocated to virtual pages only when required by a particular program which is executing, as indicated by an address translation exception created by that program. This requires that these exceptions be handled in the normal course of program execution, and that lB the exceptions be completely transparent to the faulting routine.
There are two basic approaches to restarting a program which has encountered an addressing exception. One is to resume the program at the instruction which created the exception. This requires that no instruction complete until the results of the storage address translation (if required) are known, and (in many cases) that a partially-executed instruction be undone so that it may be re-executed. Since the processor must wait on the results of the translation before proceeding to the next instruction, there is no overlap in this technique and performance is relatively poor. However, the reporting mechanism is simple. An indication of the type of fault and the address of the faulting instruction is all that is required by the control program The control program corrects the exception condition and restarts the faulting routine by a return-from-interrupt to the faulting instruction.
Another prior art approach to restarting a program which has encountered an addressing exception is to resume the faulting program at the point where the exception was detected. This allows the processor to overlap subsequent instruction execution with address translation, but requires that it provide enough information about the faulting operation(s) to the control program so that the operation(s) may be restarted when the faulting program is restarted. The restart procedure may be quite complex, since the control program must restart these operations under the same processor state (e.g. problem state) that existed when the original operation(s) faulted.
In order for instruction execution to be effectively overlapped with address translation, the instruction set must be defined so that storage operations are decoupled from other instructions. For example, an instruction which allows the incrementing of a given storage location must necessarily wait on the results of the address translation before it completes.
The Motorola 68010 microprocessor employs a scheme lB which restarts a faulting instruction at the point where it faulted instead of at its beginning. This eliminates the need to undo the partially executed instruction and in some cases reduces the number of virtual pages which must be allocated to storage for the faulting program when it is restarted. However, it requires that the processor save a large amount of information about its internal state (100 bytes) so that the instruction can be restarted at some intermediate point. The exception handling and restart sequence is therefore complex and inefficient. There is also little effective overlap of instruction execution with translation, but this is affected by the instruction set definition as well as the exception handling algorithm.
Another processor architecture allows the faulting routine to be restarted at the point where the exception was detected. The architecture provides a set of registers which indicate the storage operation type, address, and data. Certain instructions are defined to use the information in these registers to restart the faulting operation. This approach allows some overlap, but, since it is register-based, it limits the number of overlapped storage operations to one. Thus, sequences of multiple loads and stores, which are fairly common, do not execute at the maximum possible rate.
SUMMARY OF THE INVENTION
The invention described herein avoids all of the disadvantages of the methods described above Given a processor with decoupled loads and stores, this invention presents a comprehensive method for reporting and restarting faulting programs so that processor performance is maximized and control program complexity is minimized. It allows a large number of storage operations to be overlapped with instruction execution and it does not limit performance In one embodiment, the amount of information saved for each storage operation is 16 bytes, since partially-executed instructions are not exposed to the exception handler. Finally, it provides an extremely simple restart procedure for the control program. It does not rely on any additional instructions, but modifies the definition of the return-from-interrupt instruction.
BRIEF DESCRIPTION OF THE DRAWINGS
The Figure is a block diagram illustrating those portions of a data processing system needed to carry out the present invention. FIG. 2 is a flow chart illustrating the operation of the invention in handling exception and restart procedures.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The present invention employs a 32-bit register in the processor to control the saving of information about failing storage operations. This register is referred to as the Exception Control Register (ECR), and is manipulated as any other processor control register. Actual information about the failing storage operations is saved in the processor's main storage. The ECR is also used to control the restart of failing operations when the faulting program is restarted.
The Exception Control Register contains the exception count and storage address for information saved by the processor for failing storage operations. The contents of this register are defined as follows:
BITS 0-3 Reserved.
BITS 4-7 Exception Count. This four-bit field contains the exception count. When the processor is reporting exceptions, this field specifies the number of storage operations which created exceptions. When the processor is restarting failing operations, it indicates to the processor how many operations must be restarted.
BITS 8-31 Exception Save Address. This 24-bit field contains a real storage address. When the processor is reporting exceptions, this field specifies the main storage locations where information about the failing storage operations is saved. When the processor is restarting failing operations, it indicates about the failing operations so that they can be restarted.
During normal operation, the Exception Count in the ECR is set to zero. The Exception Save Address points to a block of real storage which has been reserved for saving information on the maximum number of operations which can be reported in any given implementation.
In one embodiment, the present invention provides for the saving of up to 16 bytes of information on each exception, and the actual information which is saved is processor-dependent. Table I below describes the present invention as it applies to one particular processor on which it was implemented.
TABLE I______________________________________ Exception Status Storage Block Definition______________________________________Word 0 Exception ControlWord 1 Exception AddressWord 2 Exception DataWord 3 Reserved______________________________________
Table I shows the definition of the storage block which is used to save information about a particular faulting storage operation. Each block consists of four storage fullwords (one fullword is four bytes wide). Only ten bytes are used for this particular implementation.
Exception Control Word
The first word of the Exception Status Storage Block is the Exception Control word. The Exception Control word consists of the following fields:
BITS 0-15 Reserved.
BITS 16-18 Register Set Number. This three-bit field indicates which one of the eight register sets was active when the exception occurred.
BITS 20-23 Register Number. This four-bit field specifies which one of sixteen general-purpose registers (GPR) was involved in the storage operation which encountered the exception. In the case of a load, this register number specifies which GPR was being loaded. In the case of a store, this register number specifies which GPR contained the store data. For Load Multiple (LM) and Store Multiple (STM) operations, this field specifies the first register whose load or store encountered the exception.
BITS 24-25 Operation Length. This two-bit field specifies the length of the storage operand as defined below:
00 BYTE (8 BITS)
01 HALFWORD (16 BITS)
10 FULLWORD (32 BITS)
11 HALFWORD TEST AND SET
BITS 26-28 Operation. This three-bit field specifies the type of operation that caused the exception as defined below:
000 LOAD
001 LOAD MULTIPLE
010 PROGRAMMED INPUT/OUTPUT (PIO) READ
011 ALGEBRAIC LOAD (SIGN-EXTEND)
100 STORE
101 STORE MULTIPLE
110 PIO WRITE
111 Reserved
BITS 29-30 Reserved.
BIT 31 Cancelled. This bit indicates whether the operation was cancelled when the exception was B detected. Since storage operations are overlapped with subsequent instruction execution, an instruction which follows a load may alter the register which was loaded. The load in this case is cancelled. If an exception is then detected on a cancelled load, the exception is reported, but the load operation cannot be restarted. If this bit is set to one, the operation was cancelled, and is not restarted. If it is set to zero, the operation has not been cancelled, and is restarted.
Exception Address Word
The second word of the Exception Status Storage Block is the Exception Address word. The Exception Address word consists of the following information:
BITS 0-31 Exception Address. This word contains the 32-bit effective storage address for failing storage and I/0 operations.
Exception Data Word p The third word of the Exception Status Storage Block is the Exception Data word The Exception Data word consists of the following information:
BITS 0-31 Exception Data This word contains the 32-bit data quantity for failing storage or I/O operations if the failing operation were a single store or I/O write. This word is undefined if the failing operation were a load, load multiple, IOR, or store multiple.
The fourth word of the Exception Status Block is reserved.
Storage Operation Exception Save
When the processor detects an exception, it completes the current instruction, unless that instruction depends on the storage operation being successful. For example, an ADD of two registers where one has been previously loaded from main storage cannot be completed if the load caused a storage exception. If the current instruction cannot be completed, it is cancelled. The program is later restarted at this instruction.
Upon the completion or cancellation of the current instruction, the processor must wait for all current storage operations to complete. This is so that the results of all pending storage operations may be known: information must be saved on all operations which caused exceptions, and they must be saved in the proper order. It is possible that the first exception which is detected was not caused by the operation which was issued first. When all storage operations have completed, the processor saves information on each operation which caused an exception, beginning with the operation which was issued most recent to the point of the exception, and proceeding in order to the operation which was issued least recent to the point of the exception. For each exception, the procedure for saving the information is as follows:
1. The Exception Save Address in the ECR is decremented by pixteen (four words).
2. The Exception Count in the ECR is incremented by one.
3. The Exception Control word for the next operation is saved at the real storage address specified by the Exception Save Address in the ECR. 4. The Exception Address for the next operation is saved at the real storage address given by adding four to the Exception Save Address. The value in the ECR is not changed.
5. The Exception Data for the next operation is saved at the real storage address given by adding eight to the Exception Save Address. The value in the ECR is not changed. In the cases where this Exception Data does not need to be saved, the quantity is meaningless. However, it is easier to treat all cases alike.
When the information on all exceptions has been saved, the Exception Count indicates how many operations are to be restarted. The Exception Save Address points to the Exception Control word of the first operation to be restarted. Additional operations to be restarted have information in sequential main storage locations beyond the Exception Save Address location. These operations appear in order of restart.
Storage Operation Restart
Storage operations are restarted as part of the return-from-interrupt sequence in this invention They are restarted after the new processor status is loaded, but before any instructions in the target instruction stream are executed. This means that the operations are restarted under the original processor status. To the failing routine, there is no difference in the operations which were restarted and those which were issued by the original instructions.
The return-from-interrupt instruction is defined such that storage operations are conditionally restarted during the return-from-interrupt, based on bits in the instruction. Before returning to the program which encountered the exception, the control program must correct the exception condition and set the ECR to contain the same Exception Count it contained when the exception was reported. If the Exception Status Blocks have been moved or copied in main storage, the Exception Save Address must be changed to reflect this change. The order of Exception Status Blocks must be preserved, however. The operations are restarted in order of increasing Exception Status Block addresses according to the following sequence:
1. If the Exception Count in the ECR is zero, there are no remaining operations to restart. Execution proceeds to the first instruction in the target instruction stream.
2 The Exception Control word for the next operation to be restarted is fetched from the real storage address given by Exception Save Address in the ECR. The ECR is not modified.
3. The Exception Address for the next operation to be restarted is fetched from the real storage address given by Exception Save Address plus four. The ECR is not modified.
4. The Exception Data for the next operation to be restarted is fetched from the real storage address given by Exception Save Address plus eight. The ECR is not modified.
5 The Exception Count in the ECR is decremented by one. The Exception Save Address is incremented by sixteen. The Exception Save Address then points to the next operation to be restarted (if it exists). 6. The operation is restarted using the information fetched in steps 2, 3, and 4 above. Once this operation is restarted, the restart sequence begins again with step 1.
Exceptions During Restart
If more than one exception is reported, the control program does not necessarily have to correct the exception condition for each one. In fact, it may not be possible to correct them all. The exception condition must be corrected only for the first operation to be restarted. Thus it is possible that storage operations may again encounter exceptions when they are restarted.
This possibility is handled automatically by the way the Exception Count and Exception Save Address are treated. Any exceptions during restart occur after the Exception Status Block has been saved, the Exception Count has been decremented, and the Exception Save Address has been incremented. The storage which contained the Exception Status storage block is no longer needed. Thus, if an exception occurs during restart, the information about the operation which caused the exception is saved using the procedure described previously. The information about any operations which have not been restarted when the exception occurs is still preserved in main storage. The order of restart is also preserved.
Serialization
In order to restart failing storage operations in the same environment in which they were originally executed, it is necessary to serialize certain operations. Serialization consists of completing all logically prior storage operations before the next operation occurs in order to insure that all exceptions are reported before the environment is changed. The processor must serialize all interrupts and the execution of the following instructions:
1. Any control instruction which may alter the processor status.
2. Supervisor Call.
3. Return-from-Interrupt.
4. Input/Output Write. This operation may be used to change the address translation results for a previous operation. If this change were to occur, the operation could not be restarted.
The following events occur during serialization:
1. All logically prior storage operations are completed. 2. The normal function associated with the serialization operation is performed. In the case of instruction execution, the instruction is executed after all logically prior storage operations have completed. In the case of interrupts, the PSW swap is performed after all logically prior storage operations have completed.
3. Normal instruction execution resumes.
Serialization is a common method of insuring that all operations can be restarted. However, it is not part of this invention, and is included here only for completeness. This invention does allow a significant amount of overlap in the PSW swap case, even though the serialization requirements are still enforced. The storage accesses for the PSW swap may be issued before all previous accesses have completed: it is the processor status change which cannot complete until the results of all previous accesses are known. The processor need only be able to recognize the PSW swap accesses as special cases which are not reported if an exception occurs on a previous access.
Implementation
The present invention may appear initially to require a substantial amount of additional control logic for the saving and restarting of failing storage operations. However, it has been designed to take maximum advantage of logic which already exists to overlap storage accesses with subsequent instruction execution The operation of this logic is described in the above identified copending patent application Ser. No. 615,984, "Data Processing System with CPU Register-to-Register Data Transfers Overlapped with Data Transfer To And From Main Storage".
The single figure of the present application shows a high-level data flow of the processor, emphasizing the sections needed to control storage accesses. Storage operations originate in the Control Register 11 due to execution of microcode supplied from control store 15. During the execution of the storage operation microword, the following events take place:
1. The effective address of the storage operation is calculated in the ALU 12 and sent to the storage channel interface 13. There is no register file write-back required by this execution cycle, so the register file 14 is available to accept the address from the output of the ALU. This address is saved in a temporary location so that it may be saved if an exception occurs. This location cannot be reused until the current storage operation completes.
2. Controls must be set in a tag register such as 16a and 16b to control the execution of the storage operation on subsequent cycles. The information in the tag register has a one-to-one correspondence to information defined for the
3. Exception Control word in the Exception Status Block. The tag register cannot be reused until the current storage operation completes.
3. The storage channel interface 13 is notified of the operation type, data length, etc., and the storage channel logic then completes the operation without further processor intervention.
4. Any store data required for the operation is sent on the next microcode cycle. This data is saved in a temporary register file location in file 14 as the effective address was. Again, this location cannot be reused until the storage operation completes.
The processor can issue up to sixteen operations, as long as there are available tag registers to control the accesses, and as long as there are temporary register file locations to save the addresses and data for those operations. With the system shown in the drawing, no more than two operations can be pending at any given time. It will be noted that each tag register 16a, 16b must have associated with it an indication of the order of its operation relative to the other pending operations. This is IB required so that the Exception Status Blocks may be saved in the proper order if multiple exceptions occur. Saving Exception Information
If the storage channel interface 13 indicates that a given operation has an exception, the tag register, temporary address buffer, and temporary data buffer for that operation are locked. That is, they cannot be used for any additional storage operations until the exception is reported To save the Exception Status Block for a given operation, the processor simply saves the content of its associated tag register in the Exception Control Word, the content of the temporary address buffer in the Exception Address word, and the content of the temporary data buffer in the Exception Data word. The tag register, address buffer, and data buffer for that operation are freed after the Exception Status Block has been saved.
It is possible to have the maximum number of pending storage operations with an exception on every one. This leads to the situation where all tags, address buffers, and data buffers are locked when the processor begins saving Exception Status Blocks. Thus the processor cannot use any tag, address buffer, or data buffer when storing the Exception Status Blocks. This does not create a problem since this information is saved using untranslated stores which cannot cause exceptions. Also, since stores are used, there is no need for the processor to use tag registers to control the write-back of storage data into the register file.
Operation Restart
The restarting of storage operations is fairly straight-forward. The processor simply fetches the Exception Status Blocks in the proper order, using the Exception Address in the ECR. The operation is restarted from the Control Register 11, so that the control of the restart is identical to the control of the original operation, greatly simplifying the logic required. This is accomplished by establishing a strong relationship between microcode bits in the Control Register and bits in the Exception Control Word. The Exception Control word bits are then loaded directly into the Control Register along with microcode bits which do not vary between various storage operation restarts (for example, the ALU controls are not variable since the effective address is already known). If the Exception Control word indicates that the operation was cancelled, or if it specifies an operation which could not have been created by an instruction, the Control Register is simply loaded with a NO/OP instead of the storage restart operation.
The invention described herein provides a comprehensive method of reporting and recovering from address translation exceptions in a demand paging environment. This technique was implemented on a processor which had previously restarted the failing program at the instruction which caused the exception. The implementation of the technique described here resulted in a 30% improvement in processor performance. | A method for processing address translation exceptions occurring in a virtual memory system employing demand paging and having a plurality of registers and a real storage area, includes the steps of: (a) temporarily storing for each storage operation; (i) the effective storage address for the operation; (ii) exception control word information relative to the ones of the registers involved in the operation and the length and type of the operation; and (iii) any data to be stored during the operation; (b) retrieving the temporarily stored information to form an exception status block if an exception is generated indicating a failed operation; and (c) reinitiating the failed operation based on the information contained in the exception status block. | 6 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] Not applicable.
STATEMENT OF FEDERALLY FUNDED RESEARCH/DEVELOPMENT
[0002] Not applicable.
BACKGROUND OF THE INVENTION
[0003] The invention relates to canopy structures, and in particular to damage-resistant canopies sheltering, for example, drive-up ordering stations of fast food restaurants.
[0004] It is well known to shelter from the weather particular areas, such as the drive-up ordering stations of fast food restaurants, with overhanging portions of a roof or a free-standing canopy structure. These structures are rigid and fixed in height. Consequently, they provide a prescribed maximum clearance for pedestrian or vehicular travel thereunder. The amount of clearance for roof overhangs usually depends on the height of the building to which it is attached. The height of the canopy may be selected to balance the competing interests of maximum clearance and adequate protection from the elements. That is, the canopy must not be too much higher than the subjects being sheltered, otherwise it may provide insufficient shelter because the weather elements (wind, rain, sleet, snow, etc.) may easily pass around the canopy. The size of the canopy structure is also selected with an eye to material and assembly costs. At the drive-up ordering station of a fast food restaurant, for example, a canopy with 100 inches of clearance may be selected to provide adequate shelter and still allow automobiles and many sizes of trucks to pass underneath.
[0005] It is possible for the canopy top to be struck by vehicles that are taller, or are carrying loads that are higher, than the maximum clearance. This can cause the canopy and the vehicle (or load) to be damaged. To overcome this problem, canopy structures have been designed with components that move or break-away when struck. For example, U.S. Pat. No. 5,390,710, incorporated herein by reference, discloses a canopy assembly having an upright post and a canopy top that can be pivoted about the post (and out of the way) by an overheight vehicle. The canopy top has an impact bar at a leading edge that when struck activates an alarm and travels a small distance. If the vehicle does not stop, the impact bar travels a further distance to release a latch and allow the canopy top to be swung by the vehicle out of the path of movement. While this device provides a damage-resistant canopy, it must be returned manually to the centered position after the vehicle has passed out of the way. Until the canopy top is repositioned, it will not shelter the desired area and it may be swung about the post by external forces, such as high wind, thus subjecting it (and nearby structures) to damage.
[0006] Accordingly, there exists a need for an improved canopy structure.
SUMMARY OF THE INVENTION
[0007] The present invention provides a self-centering pivotal canopy assembly overcoming the problems of the prior art. In particular, the canopy assembly includes a support column, at an upper end, a roof structure having a frame supporting one or more sheltering members. A coupler is attached to the column and the roof to allow the roof to be pivoted about the column in response to a moment force about the column. A centering element is mounted to the support column to engage the coupler and bias the roof to a center position such that the roof returns to the center position in the absence of the moment force.
[0008] In one form, the coupler includes a pair of identical helical slots. In the centered position, the top ends of the slots rest on the pivot post. The coupler can rotate through approximately 180 degrees until the pivot post contacts a bottom end of the helical slots. When the coupler is rotated, the pivot post engages the slots so that the coupler translates upward. Gravity biases the coupler to return to the centered position. Preferably, the pivot post assembly includes a cylindrical rod fixed to the support column and supporting a plurality of cylindrical glides that ride within the helical slots.
[0009] In another form, a plastic spacer sleeve is disposed in the cavity between the coupler. The support column, coupler and spacer sleeve have a pair of openings aligned to receive the pivot post. The spacer sleeve has a top end with at least one wing extending outwardly to engage the top end of the support column.
[0010] The roof can also include a rectangular, perforated bottom panel that is supported by a the lip of a skirt extending around the perimeter of the roof frame. A front section of the skirt can be pivoted away from the frame to allow the bottom panel to be slid out from the roof assembly for accessing lighting mounted underneath the sloping panels of the roof assembly.
[0011] In a preferred form, the present invention provides a canopy assembly for sheltering a drive-up ordering station of a fast food restaurant that can pivot out of the path of a vehicle impacting a leading end of a pivotal portion of the assembly. The canopy assembly includes a support column mounting a roof assembly at a coupler. The support column has an upper end defining a cavity in which is disposed a plastic spacer sleeve through which a pivot post assembly extends across the cavity. The pivot post assembly includes a cylindrical rod fixed to the support column and supporting a plurality of cylindrical glides which ride within a pair of helical slots in the tubular coupler, which is mounted to the frame of the roof assembly. When the coupler is rotated, the pivot post engages the slots so that the coupler translates upward so that the coupler is biased by gravity to a centered position in which the top ends of the slots engage the pivot post. The coupler can rotate through approximately 180 degrees in which the pivot post engages a bottom end of the helical slots.
[0012] Thus, the invention provides a canopy assembly having a roof assembly that can pivot when impacted by a vehicle that is taller than the maximum clearance height of the canopy assembly. After the vehicle is passed clear of the canopy, the pivotal roof assembly automatically returns to its initial centered position, without manual intervention being necessary.
[0013] These and other advantages of the invention will be apparent from the detailed description and drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] [0014]FIG. 1 is a perspective view of a self-centering pivotal canopy assembly of the present invention;
[0015] [0015]FIG. 2 is a front view of the canopy assembly;
[0016] [0016]FIG. 3 is a right side view of the canopy assembly;
[0017] [0017]FIG. 4 is a top view of the canopy assembly;
[0018] [0018]FIG. 5 is an exploded assembly view of the canopy assembly;
[0019] [0019]FIG. 6 is a top view looking down on a pivot assembly and support column from line 6 - 6 of FIG. 2;
[0020] [0020]FIG. 7 is a cut out view taken along arc 7 - 7 of FIG. 1, showing a glide bar in a pair of helical slots;
[0021] [0021]FIG. 8A shows the canopy assembly with the roof assembly centered;
[0022] [0022]FIG. 8B shows the canopy assembly with the roof assembly pivoted 90 degrees;
[0023] [0023]FIG. 8C shows the canopy assembly with the roof assembly pivoted 180 degrees; and
[0024] [0024]FIG. 9 is a rear view of a pivotal front skirt section, showing a perforated bottom panel in cross-section.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0025] Although other applications are envisioned, the canopy assembly of the present invention is designed to shelter the drive-up, ordering station at a fast food restaurant. Referring to FIGS. 1 - 5 , the canopy assembly 10 includes as primary components a support column 12 to which is mounted a roof assembly 14 at a pivot assembly 16 . The canopy assembly 10 stands approximately 125 inches tall, with approximately 98 inches of clearance beneath the roof assembly 14 , which is enough to allow automobiles and other passenger vehicles as well as many standard height commercial vehicles to pass thereunder. The canopy assembly 10 thus provides restaurant customers shelter from inclement weather, such as rain, sleet and snow, when ordering. As will be explained, the canopy assembly 10 is designed so that the roof assembly 14 will swing out of the way when impacted by an extra tall vehicle, thereby avoiding substantial damage to the vehicle and the canopy assembly 10 .
[0026] The support column 12 is a square tubular member with a flanged top end 18 and a flanged bottom end 20 for anchoring the canopy assembly 10 to the ground by suitable bolts or anchors. When used to shelter the ordering station of a restaurant, a two-way communication device 22 with a speaker and microphone is mounted to the support column 12 at a suitable height from the ground to facilitate communication between a customer and the restaurant personnel.
[0027] The roof assembly 14 includes a rigid rectangular frame 24 with leading end 26 and trailing end 28 members joined together by a front 30 member and two shorter rear members 32 and 34 . A center brace 36 is connected to the middle of the front member 30 and the inner ends of the rear members 32 and 34 . The center brace 36 extends beyond the rear members 32 and 34 and a mounting plate 38 is attached at the intersection of the center brace 36 and the rear members 32 and 34 . The mounting plate 38 includes four through bores (not shown) in which bolts are disposed for fastening the roof assembly 14 to the pivot assembly 16 , described in detail below. The members of the frame 24 are preferably a stock, heavy-gauge, square tubular steel joined together by suitable weldment. Gussets (not shown) are used at the connection of the center brace 36 to the front member 30 and the rear members 32 and 34 .
[0028] The frame 24 supports a canopy 42 having any suitable configuration, but preferably having sloped front 44 and rear 46 sides joined together at a top ridgeline peak 48 and to the front 30 and rear 32 , 34 members, respectively. The sides 44 , 46 are preferably formed of aluminum stiles 50 with panels 52 fastened therebetween. Two triangular end panels 54 cap the leading 26 and trailing 28 ends. A skirt 56 extends around, and slightly below, the front 30 , rear 32 , 34 and end 26 , 28 members of the frame 24 to support a bottom panel 50 , (see FIG. 9) which is preferably a perforated metal sheet. Referring to FIG. 9, the skirt 56 has an L-shaped cross-section and defines a ledge 60 for supporting the perimeter of the bottom panel 58 . A front section 62 of the skirt 56 can pivot away from the frame 24 to allow the bottom panel 58 to be slid out for accessing suitable lamps (not shown) mounted within the roof assembly 14 beneath the canopy 42 .
[0029] Referring to FIGS. 5, 6 and 7 , the pivot assembly 16 includes a cylindrical pivot tube 64 having a top end flange 66 and a pair of opposing helical slots 68 and 70 . The top end flange 66 includes four bores 40 for bolts (not shown) used to secure the pivot tube 64 to the mounting plate 38 of the roof assembly 14 . The helical slots 68 and 70 are preferably cut through the pivot tube 64 using a laser cutting machine at opposite portions of the pivot tube 64 (as shown in FIGS. 5 and 7). The slots 68 and 70 allow the roof assembly 14 to pivot through approximately 180 degrees in the counter-clockwise direction. Preferably, the pivot tube 64 is disposed within a spacer sleeve 72 having a square cross-section and made of a self-lubricating material, such as polyethylene. The spacer sleeve 72 fits within the hollow, square cavity defined by the upper end of the support column 12 and is molded to include a pair of wings 74 that rest on the top end flange 18 of the support column. The sleeve 72 , pivot tube 64 and support column 12 are coupled together by a stationary post assembly 76 . The post assembly 76 , wings 74 and the square walls of the sleeve 72 prevent the sleeve 72 from rotating or moving within the support column 12 and allow the pivot tube 64 to rotate and translate within the sleeve 72 .
[0030] Referring to FIGS. 5, 6 and 7 , the post assembly 76 includes a cylindrical rod 78 with a smooth outer diameter and a threaded inner diameter at its ends. About the rod 78 fit three cylindrical glides 80 made of a suitable self-lubricating material. The rod 78 is sized to fit through bores 82 in the support column 12 and bores 73 in the spacer sleeve 72 so that the two outer glides ride within the helical slots 68 and 70 of the pivot tube 64 . A pair of bushings fit 84 within the bores 82 in the support column 12 and allow the rod 78 to rotate as needed. The rod 78 is secured to the support column 12 by threaded fasteners 86 . The bushings 84 and washers 88 disposed about the rod 78 prevent the threaded fasteners 86 from inhibiting rotation of the rod 78 when the fasteners 86 are tightened.
[0031] In use, the canopy assembly 10 is ordinarily in the position shown by FIG. 8A. In this position, the roof assembly 14 is centered, that is oriented so that the front member 30 faces front, i.e., the side with the communication device 22 , so as to provide a ceiling for the ordering area and thereby shelter persons from rain, snow, etc. when ordering. The bottom of the roof assembly 14 rests at a clearance height (h) above the ground. In this position, the pivot tube 64 rests on the post assembly 76 at top ends 90 of the helical 68 and 70 slots, as shown in FIG. 7. As such, the roof assembly can pivot in only one direction, namely, counterclockwise. This direction is chosen because typically vehicles will be approaching the canopy assembly 10 from the leading end 26 because vehicle operators in the United States are seated on the left-hand side of the vehicles. In the event that the vehicle is too tall to fit under the roof assembly 14 , the vehicle will contact the leading end 26 and create a moment, or rotational force, on the roof assembly 14 and, in turn, the pivot tube 64 . Since the post assembly 76 is fixed in position, it will contact the slots 68 and 70 and force the pivot tube 64 to travel upward as it rotates.
[0032] When the roof assembly 14 has pivoted 90 degrees, as shown in FIG. 8B, it will be raised upward (D/2), which is roughly one-half the total travel distance (D) allowed. In this position, the post assembly 76 is approximately in the meddle of helical slots 68 and 70 . The pivot tube 64 and roof assembly 14 will continue to rotate while the counter-clockwise rotational force is applied, i.e., while in contact with the vehicle, until the post assembly 76 contacts bottom ends 92 of the slots 68 and 70 . In this position, as shown in FIG. 8C, the pivot tube 64 and roof assembly 14 will have rotated through 180 degrees and traveled upward the total travel distance (D), roughly 6-8 inches. By rotating 180 degrees, the roof assembly 14 is capable of swinging completely clear of the vehicle to prevent or reduce damage to the vehicle and the canopy assembly 10 .
[0033] Once the vehicle has passed by the canopy assembly 10 so that a rotational force is no longer acting on the roof assembly 14 , the weight of the roof assembly 14 will apply a downward force on the pivot tube 64 . The pivot tube 64 will then be rotated clockwise and travel downward until the top ends 90 of the slots 68 and 70 contact and rest on the post assembly 76 . Thus, the roof assembly 14 returns automatically to the initial, centered position.
[0034] A preferred embodiment of the invention has been described in considerable detail. Many modifications and variations to the preferred embodiment will be apparent to those skilled in the art, which will be within the spirit and scope of the invention. Therefore, the invention should not be limited to the described embodiment, rather the following claims should be referenced. | A canopy assembly for sheltering a drive-up ordering station of a fast food restaurant can pivot out of the way when impacted by a vehicle and return automatically to a centered position. A centering feature mounted to a column supporting a roof structure engages a pivotal coupler to bias the roof to a center position. This feature includes a pivot post assembly extending across the cavity and through a pair of helical slots in the coupler. When a leading end of the roof assembly is struck by a vehicle, the coupler is rotated and the pivot post engages the slots so that the coupler translates upward. The coupler is biased by gravity to a centered position in which the top ends of the slots rest on the pivot post. | 4 |
This application is a continuation of application Ser. No. 09/184,982, filed Nov. 3, 1998, now abandoned, which claims the benefit of Provisional application Ser. No. 60/004,116, filed Nov. 3, 1997.
TECHNICAL FIELD
The present invention relates, in general, to a method of modulating physiological and pathological processes and, in particular, to a method of modulating cellular levels of oxidants and thereby processes in which such oxidants are a participant. The invention also relates to compounds and compositions suitable for use in such methods.
BACKGROUND
Oxidants are produced as part of the normal metabolism of all cells but also are an important component of the pathogenesis of many disease processes. Reactive oxygen species, for example, are critical elements of the pathogenesis of diseases of the lung, the central nervous system and skeletal muscle. Oxygen free radicals also play a role in modulating the effects of nitric oxide (NO·). In this context, they contribute to the pathogenesis of vascular disorders, inflammatory diseases and the aging process.
A critical balance of defensive enzymes against oxidants is required to maintain normal cell and organ function. Superoxide dismutases (SODs) are a family of metalloenzymes that catalyze the intra- and extracellular conversion of O 2 − into H 2 O 2 plus O 2 , and represent the first line of defense against the detrimental effects of superoxide radicals. Mammals produce three distinct SODs. One is a dimeric copper- and zinc-containing enzyme (CuZn SOD) found in the cytosol of all cells. A second is a tetrameric manganese-containing SOD (Mn SOD) found within mitochondria, and the third is a tetrameric, glycosylated, copper- and zinc-containing enzyme (EC-SOD) found in the extracellular fluids and bound to the extracellular matrix. Several other important antioxidant enzymes are known to exist within cells, including catalase and glutathione ceroxidase. While extracellular fluids and the extracellular matrix contain only small amounts of these enzymes, other extracellular antioxidants are also known to be present, including radical scavengers and inhibitors of lipid peroxidation, such as ascorbic acid, uric acid, and α-tocopherol (Halliwell et al, Arch. Biochem. Biophys. 280:1 (1990)).
The present invention relates generally to low molecular weight porphyrin compounds suitable for use in modulating intra- and extracellular processes in which superoxide radicals, or other oxidants such as hydrogen peroxide or peroxynitrite, are a participant. The compounds and methods of the invention find application in various physiologic and pathologic processes in which oxidative stress plays a role.
SUMMARY OF THE INVENTION
The present invention relates to a method of modulating intra- or extracellular levels of oxidants such as superoxide radicals, hydrogen peroxide, peroxynitrite, lipid peroxides, hydroxyl radicals and thiyl radicals. More particularly, the invention relates to a method of modulating normal or pathological processes involving superoxide radicals, hydrogen peroxide, nitric oxide or peroxynitrite, using low molecular weight antioxidants, and to methine (ie, meso) substituted porphyrins suitable for use in such a method. The substituted porphyrins are also expected to have activity as antibacterial and antiviral agents, and as ionophores and chemotherapeutics. Objects and advantages of the present invention will be clear from the description that follows.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 . Mechanism.
FIG. 2 . Manganese meso-tetrakis-N-alkyl-pyridinium based porphyrins.
FIG. 3 . SOD activity in vivo ( E. coli ) of 1, 2, 3* and 4* (20 μM) in minimal medium (mixture of atropoisomers, JI=SOD deficient strain, AB=parental strain).
FIG. 4 . Structures of MnCl x TE-2-PyP 5+ (x=1 to 4).
FIG. 5. 1 H-NMR spectrum (porphyrin ring) of H 2 Cl 2a T-2-PyP in CDCl 3 (δ=7.24 ppm). The four protons in alpha position of the four pyridyl nitrogens are taken as integration reference.
FIG. 6 . Plot of the free energy of activation (ΔG # ) for the O 2 − dismutation reaction catalyzed by MnCl x TE-2-PyP 5+ as a function of the ground state free energy change (ΔG°) for MnCl x TE-2-PyP 5+ redox. ΔG # and ΔG° were calculated from k cat and E° 1/2 values reported in Table 4 (E, R, h and k B are Faraday, molar gas, Planck and Boltzmann constants, respectively).
Numbers 0-4 correspond to x in MnCl x TE-2-PyP 5+ Corresponding data for one active site of Cu,Zn-SOD (Ellerby et al, J. Am. Chem. Soc. 118:6556 (1996)).
FIG. 7 . Illustrated are the chemical structures of three classes of antioxidants. A) The meso-porphyrin class is depicted where: R 1 is either a benzoic acid (tetrakis-(4-benzoic acid) porphyrin (TBAP)) or a N-methyl group in the 2 or 4 position of the pyridyl (tetrakis-(N-methyl pyridinium-2(4)-yl) porphyrin (TM-2-PyP, TM-4-PyP)); R 2 is either a hydrogen (H) or a bromide (Br, OBTM-4-PyP) and where the porphyrin is ligated with either a manganese (Mn), cobalt (Co), iron (Fe), or zinc (Zn) metal. B) The vitamin E analog class is represented by trolox. C) The flavanoid class is represented by rutin.
FIG. 8 . The time course of iron/ascorbate mediated oxidation of rat brain homogenates. Rat brain homogenates were incubated for various times with 0.25 μM FeCl 2 and 1 μM ascorbate, and lipid peroxidation was measured as thiobarbituric acid reactive species (TBARS) spectrophotometrically at 535 nm (n=3).
FIG. 9 . The comparison of trolox (▪), rutin (▴), bovine CuZnSOD (●), MnOBTM-4-PyP (▾) and MnTM-2-PyP (♦) in their ability to inhibit iron/ascorbate mediated oxidation of rat brain homogenates. Rat brain homogenates were incubated for 30 minutes with 0.25 μM FeCl 2 and 1 μM ascorbate, and lipid peroxidation was measured as thiobarbituric acid reactive species. The amount of TBARS formed in 30 minutes was expressed as 100% lipid peroxidation (n=3-6). Sigmoidal dose response curves were derived from fitting the data to a non-linear regression program.
FIG. 10 . The comparison of manganic (▴), cobalt (●), iron (▾) and zinc (▪) analogs of TBAP in their ability to inhibit iron/ascorbate mediated oxidation of rat brain homogenates. Rat brain homogenates were incubated for 30 minutes with 0.25 μM FeCl 2 and 1 μM ascorbate, and lipid peroxidation was measured as thiobarbituric acid reactive species. The amount of TBARS formed in 30 minutes was expressed as 100% lipid peroxidation (n=3-6). Sigmoidal dose response curves were derived from fitting the data to a non-linear regression program.
FIG. 11 . The comparison of manganic (solid) and zinc (open) analogs of TM-4-PyP (squares) and TM-2-PyP (triangles) in their ability to inhibit iron/ascorbate mediated oxidation of rat brain homogenates. Rat brain homogenates were incubated for 30 minutes with 0.25 μM FeCl 2 and 1 μM ascorbate, and lipid peroxidation was measured as thiobarbituric acid reactive species. The amount of TBARS formed in 30 minutes was expressed as 100% lipid peroxidation (n=3-6). Sigmoidal dose response curves were derived from fitting the data to a non-linear regression program.
DETAILED DESCRIPTION OF THE INVENTION
The present invention relates to methods of protecting against the deleterious effects of oxidants, particularly, superoxide radicals, hydrogen peroxide and peroxynitrite, and to methods of preventing and treating diseases and disorders that involve or result from oxidant stress. The invention also relates methods of modulating biological processes involving oxidants, including superoxide radicals, hydrogen peroxide, nitric oxide and peroxynitrite. The invention further relates to compounds and compositions, including low molecular weight antioxidants (eg mimetics of scavengers of reactive oxygen species, including mimetics of SODs, catalases and peroxidases) and formulations thereof, suitable for use in such methods.
Mimetics of scavengers of reactive oxygen species appropriate for use in the present methods include methine (ie meso) substituted porphines, or pharmaceutically acceptable salts thereof. The invention includes both metal-free and metal-bound porphines. In the case of metal-bound porphines, manganic derivatives of methane (meso) substituted porphines are preferred, however, metals other than manganese, such as iron (II or III), copper (I or II), cobalt (II or III), or nickel (I or II), can also be used. It will be appreciated that the metal selected can have various valence states, for example, manganese II, III or V can be used. Zinc (II) can also be used even though it does not undergo a valence change and therefore will not directly scavenge superoxide. The choice of the metal can affect selectivity of the oxygen species that is scavenged. Iron-bound porphines, for example, can be used to scavenge NO· while manganese-bound porphines cannot. These metal bound porphines scavenge peroxynitrite; iron, nickel and cobalt bound porphines tend to have the highest reactivity with peroxynitrite.
Preferred mimetics of the invention are of Formula I or II:
or pharmaceutically acceptable salt thereof, wherein R is C 1 -C 8 alkyl, preferably, C 1 -C 4 alkyl, more preferably, methyl, ethyl or isopropyl, most preferably methyl. This mimetic can also be present metal-free or bound to a metal other than Mn. All atropoisomers of the above are within the scope of the invention, present in isolated form or as a mixture of at least two. Atropoisomers wherein at least 3, preferably 4, of the R groups are above the porphyrin ring plane can be particularly advantageous.
One or more of the pyrrole rings of the porphyrin of Formula I or II can be substituted at any or all beta carbons, ie: 2, 3, 7, 8, 12, 13, 17 or 18. Such substituents, designated P, can be an electron withdrawing group, for example, each P can, independently, be a NO 2 group, a halogen (eg Cl, Br or F), a nitrile, a vinyl group, or a formyl group. For example, there can be 1, 2, 3, 4, 5, 6, 7 or 8 halogen (eg Br) substituents (when there are less than 8 halogen substituents, the remaining P's are advantageously hydrogen). Such substituents alter the redox potential of the porphyrin and thus enhance its ability to scavenge oxygen radicals. Each P can, independently, also be hydrogen. When P is formyl, it is preferred that there be not more than 2 (on non adjacent carbons), more preferably 1, the remaining P's being hydrogen. When P is NO 2 , it is preferred that there be not more than 4 (on non adjacent carbons), more preferably 1 or 2, the remaining P's being hydrogen.
Mimetics suitable for use in the present methods can be selected by assaying for SOD, catalase and/or peroxidase activity and stability. Mimetics can also be screened for their ability to inhibit lipid peroxidation in tissue homogenates using iron and ascorbate to initiate the lipid peroxidation and measuring the formation of thiobarbituric acid reactive species (TBARS) (Ohkawa et al, Anal. Biochem. 95:351 (1979) and Yue et al, J. Pharmacol. Exp. Ther. 263:92 (1992)). The selective, reversible and SOD-sensitive inactivation of aconitase by known O − 2 generators can be used as a marker of intracellular O − 2 generation. Thus, suitable mimetics can be selected by assaying for the ability to protect aconitase activity.
SOD activity can be monitored in the presence and absence of EDTA using the method of McCord and Fridovich (J. Biol. Chem. 244:6049 (1969)). The efficacy of a mimetic can also be determined by measuring the effect of the mimetic on the aerobic growth of a SOD null E. coli strain versus a parental strain lacking the specific mutations. Specifically, parental E. coli (AB1157) and SOD null E. coli . (JI132) can be grown in M9 medium containing 0.2% casamino acids and 0.2% glucose at pH 7.0 and 37° C.; growth can be monitored in terms of turbidity followed at 700 nm. This assay can be made more selective for SOD mimetics by omitting the branched chain, aromatic and sulphur containing amino acids from the medium (glucose minimal medium (M9), plus 5 essential amino acids) (see Example V).
Efficacy of active mimetics can also be assessed by determining their ability to protect mammalian cells against methylviologen (paraquat)-induced toxicity Specifically, rat L2 cells grown as described below and seeded into 24 well dishes can be pre-incubated with various concentrations of the SOD mimetic and then incubated with a concentration of methylviologen previously shown to produce an LC 75 in control L2 cells. Efficacy of the mimetic can be correlated with a decrease in the methylviologen-induced LDH release (St. Clair et al, FEBS Lett. 293:199 (1991)).
The efficacy of SOD mimetics can be tested in vivo with mouse and/or rat models using both aerosol administration and parenteral injection. For example, male Balb/c mice can be randomized into 4 groups of 8 mice each to form a standard 2×2 contingency statistical model. Animals can be treated with either paraquat (40 mg/kg, ip) or saline and treated with SOD mimetic or vehicle control. Lung injury can be assessed 48 hours after paraquat treatment by analysis of bronchoalveolar lavage fluid (BALF) damage parameters (LDH, protein and % PMN) as previously described (Hampson et al, Tox. Appl. Pharm. 98:206 (1989); Day et al, J. Pharm. Methods 24:1 (1990)). Lungs from 2 mice of each group can be instillation-fixed with 4% paraformaldehyde and processed for histopathology at the light microscopic level.
Catalase activity can be monitored by measuring absorbance at 240 nm in the presence of hydrogen peroxide (see Beers and Sizer, J. Biol. Chem. 195:133 (1952)) or by measuring oxygen evolution with a Clark oxygen electrode (Del Rio et al, Anal. Biochem. 80:409 (1977)). Peroxidase activity can be measured spectrophotometrically as previously described by Putter and Becker: Peroxidases. In: Methods of Enzymatic Analysis, H. U. Bergmeyer (ed.), Verlag Chemie, Weinheim, pp. 286-292 (1983). Aconitase activity can be measured as described by Gardner and Fridovich (J. Biol. Chem. 266:19328 (1991)). The ability of mimetics to inhibit lipid peroxidation is assessed as described by Ohkawa et al (Anal. Biochem. 95:351 (1979)) and Yue et al (J. Pharmacol. Exp. Ther. 263:92 (1992)).
Active mimetics can be tested for toxicity in mammalian cell culture by measuring lactate dehydrogenase (LDH) release. Specifically, rat L2 cells (a lung Type II like cell; (Kaighn and Douglas, J. Cell Biol. 59:160a (1973)) can be grown in Ham's F-12 medium with 10% fetal calf serum supplement at pH 7.4 and 37° C.; cells can be seeded at equal densities in 24 well culture dishes and grown to approximately 90% confluence; SOD mimetics can be added to the cells at log doses (eg micromolar doses in minimal essential medium (MEM)) and incubated for 24 hours. Toxicity can be assessed by morphology and by measuring the release of the cytosolic injury marker, LDH (eg on a thermokinetic plate reader), as described by Vassault (In: Methods of Enzymatic Analysis, Bergmeyer (ed) pp. 118-26 (1983); oxidation of NADH is measured at 340 nm).
Synthesis of mimetics suitable for use in the present method can be effected using art-recognized protocols (see also Examples I, II, III and IV and Sastry et al, Anal. Chem. 41:857 (1969), Pasternack et al, Biochem. 22:2406 (1983); Richards et al, Inorg. Chem. 35:1940 (1996) and U.S. application Ser. No. 08/663,028, particularly the details therein relating to syntheses). Separation of atropoisomers can be effected using a variety of techniques.
One specific embodiment of the present invention relates to a method of regulating NO· levels by targeting the above-described porphines to strategic locations. NO· is an intercellular signal and, as such, NO· must traverse the extracellular matrix to exert its effects. NO·, however, is highly sensitive to inactivation mediated by O 2 − present in the extracellular spaces. The methine (meso) substituted porphyrins of the invention can increase bioavalability of NO· by preventing its degradation by O 2 − .
In a further embodiment, the mimetics of the invention are used as catalytic scavengers of reactive oxygen species to protect against ischemia reperfusion injuries associated with myocardial infarction, stroke, acute head trauma, organ reperfusion following transplantation, bowel ischemia, hemorrhagic shock, pulmonary infarction, surgical occlusion of blood flow, and soft tissue injury. The mimetics can further be used to protect against skeletal muscle reperfusion injuries. The mimetics can also be used to protect against damage to the eye due to sunlight (and to the skin) as well as glaucoma, and macular degeneration in the eye. The mimetics can also be used to protect against and/or treat cataracts. The mimetics can also be used to protect against and/or treat inflammatory diseases of the skin (e.g., psoriasis). Diseases of the bone are also amenable to treatment with the mimetics. Further, connective tissue disorders associated with defects in collagen synthesis or degradation can be expected to be susceptible to treatment with the present mimetics, as should the generalized deficits of aging.
In yet another embodiment, the mimetics of the invention can be used as catalytic scavengers of reactive oxygen species to increase the very limited storage viability of transplanted hearts, kidneys, skin and other organs and tissues. The invention also provides methods of inhibiting damage due to autoxidation of substances resulting in the formation of O 2 − including food products, pharmaceuticals, stored blood, etc. To effect this end, the mimetics of the invention are added to food products, pharmaceuticals, stored blood and the like, in an amount sufficient to inhibit or prevent oxidation damage and thereby to inhibit or prevent the degradation associated with the autoxidation reactions. (For other uses of the mimetics of the invention, see U.S. Pat. No. 5,227,405). The amount of mimetic to be used in a particular treatment or to be associated with a particular substance can be determined by one skilled in the art.
In yet another embodiment, the mimetics of the invention can be used to scavenge hydrogen peroxide and thus protect against formation of the highly reactive hydroxyl radical by interfering with Fenton chemistry (Aruoma and Halliwell, Biochem. J. 241:273 (1987); Mello Filho et al, Biochem. J. 218:273 (1984); Rush and Bielski, J. Phys. Chem. 89:5062 (1985)). The mimetics of the invention may also be used to scavenge peroxynitrite, as demonstrated indirectly by inhibition of the oxidation of dihydrorhodamine 123 to rhodamine 123 and directly by accelerating peroxynitrite degradation by stop flow analysis.
Further examples of specific diseases/disorders appropriate for treatment using the mimetics of the present invention include diseases of the central nervous system (including AIDS dementia, stroke, amyotrophic lateral sclerosis (ALS), Parkinson's disease and Huntington's disease) and diseases of the musculature (including diaphramic diseases (eg respiratory fatigue in emphysema, bronchitis and cystic fibrosis), cardiac fatigue of congestive heart failure, muscle weakness syndromes associated with myopathies, ALS and multiple sclerosis). Many neurologic disorders (including stroke, Huntington's disease, Parkinson's disease, ALS, Alzheimer's and AIDS dementia) are associated with an over stimulation of the major subtype of glutamate receptor, the NMDA (or N-methyl-D-aspartate) subtype. On stimulation of the NMDA receptor, excessive neuronal calcium concentrations contribute to a series of membrane and cytoplasmic events leading to production of oxygen free radicals and nitric oxide (NO·). Interactions between oxygen free radicals and NO· have been shown to contribute to neuronal cell death. Well-established neuronal cortical culture models of NMDA-toxicity have been developed and used as the basis for drug development. In these same systems, the mimetics of the present invention inhibit NMDA-induced injury. The formation of O − 2 radicals is an obligate step in the intracellular events culminating in excitotoxic death of cortical neurons and further demonstrate that the mimetics of the invention can be used to scavenge O − 2 radicals and thereby serve as protectants against excitotoxic injury.
The present invention also relates to methods of treating AIDS. The NfKappa B promoter is used by the HIV virus for replication. This promoter is redox sensitive, therefore, an antioxidant can regulate this process. This has been previously shown for two metalloporphyrins distinct from those of the present invention (Song et al, Antiviral Chem. And Chemother. 8:85 (1997)). The invention also relates to methods of treating arthritis, systemic hypertension, atherosclerosis, edema, septic shock, pulmonary hypertension, including primary pulmonary hypertension, impotence, MED, infertility, endometriosis, premature uterine contractions, microbial infections, gout and in the treatment of Type I and Type II diabetes mellitus. The mimetics of the invention can be used to ameliorate the toxic effects associated with endotoxin, for example, by preserving vascular tone and preventing multi-organ system damage.
Inflammations, particularly inflammations of the lung, are amenable to treatment using the present invention (note particularly the inflammatory based disorders of asthma, ARDS including oxygen toxicity, pneumonia (especially AIDS-related pneumonia), cystic fibrosis, chronic sinusitis and autoimmune diseases (such as rheumatoid arthritis)). EC-SOD is localized in the interstitial spaces surrounding airways and vasculature smooth muscle cells. EC-SOD and O 2 − mediate the antiinflammatory-proinflammatory balance in the alveolar septum. NO· released by alveolar septal cells acts to suppress inflammation unless it reacts with O 2 − to form ONOO − . By scavenging O 2 − , EC-SOD tips the balance in the alveolar septum against inflammation. Significant amounts of ONOO − will form only when EC-SOD is deficient or when there is greatly increased O 2 − release. Mimetics described herein can be used to protect against destruction caused by hyperoxia.
The invention further relates to methods of treating memory disorders. It is believed that nitric oxide is a neurotransmitter involved in long-term memory potentiation. Using an EC-SOD knocked-out mouse model (Carlsson et al, Proc. Natl. Acad. Sci. USA 92:6264 (1995)), it can be shown that learning impairment correlates with reduced superoxide scavenging in extracellular spaces of the brain. Reduced scavenging results in higher extracellular O − 2 levels. O − 2 is believed to react with nitric oxide thereby preventing or inhibiting nitric oxide-medicated neurotransmission and thus long-term memory potentiation. The mimetics of the invention can be used to treat dementias and memory/learning disorders.
The availability of the mimetics of the invention also makes possible studies of processes mediated by O 2 − , hydrogen peroxide, nitric oxide and peroxynitrite.
The mimetics described above can be formulated into pharmaceutical compositions suitable for use in the present methods. Such compositions include the active agent (mimetic) together with a pharmaceutically acceptable carrier, excipient or diluent. The composition can be present in dosage unit form for example, tablets, capsules or suppositories. The composition can also be in the form of a sterile solution suitable for injection or nebulization. Compositions can also be in a form suitable for opthalmic use. The invention also includes compositions formulated for topical administration, such compositions taking the form, for example, of a lotion, cream, gel or ointment. The concentration of active agent to be included in the composition can be selected based on the nature of the agent, the dosage regimen and the result sought.
The dosage of the composition of the invention to be administered can be determined without undue experimentation and will be dependent upon various factors including the nature of the active agent, the route of administration, the patient, and the result sought to be achieved. A suitable dosage of mimetic to be administered, for example, IV or topically, can be expected to be in the range of about 0.01 to 100 mg/kg/day, preferably 0.1 to 10 mg/kg/day. For aerosol administration, it is expected that doses will be in the range of 0.01 to 1.0 mg/kg/day. Suitable doses of mimetics will vary, for example, with the mimetic and with the result sought. The results of Faulkner et al (J. Biol. Chem. 269:23471 (1994)) indicate that the in vivo oxidoreductase activity of the mimetics is such that a pharmaceutically effective dose will be low enough to avoid problems of toxicity. Doses that can be used include those in the range of 1 to 50 mg/kg.
Certain aspects of the present invention will be described in greater detail in the non-limiting Examples that follow.
EXAMPLES
The following chemicals were utilized in Examples I-V that follow.
The chloride salts of ortho and meta metal-free ligands (H 2 TM-2-PyPCl 5 and H 2 TM-3-PyPCl 5 ) were purchased from MidCentury Chemicals, and the tosylate salts of the para metal-free ligand H 2 TM-4-PyP(CH 5 PhSO 3 ) 5 ) were purchased from Porphyrin Products. The purity was checked in terms of elemental analysis and spectral properties, ie, molar absorptivities and corresponding wave-length of the Soret bands. The Soret band properties of metal-free ligands were ε 413.3 nm =2.16×10 5 M −1 cm −1 (H 2 TM-2-PyPCl 4 ), ε 416.6 nm =3.18×10 5 M −1 cm −1 (H 2 TM-3-PyPCl 4 ), ε 422.0 nm =2.35×10 5 M −1 cm −1 (H 2 TM-4-PyPCl 4 ). The non-methylated ortho metal-free ligand (H 2 T-2-PyP) was bought from MidCentury Chemicals and the purity checked in terms of elemental analysis (see below). Iodoethane, 1-iodobutane, anhydrous manganese chloride (MnCl 2 ), MnCl 2 .4H 2 O, tetrabutylammonium chloride (TBA) and ammonium hexafluorophosphate (PF 6 NH 4 ) were purchased from Aldrich.
Example I
Synthesis of meso-tetrakis-(N-methylpyridinium-2-yl)porphyrin and meso-tetrakis-(N-methylpyridinium-3-yl)porphyrin
Metal-free porphyrins meso-tetrakis-(2-pyridyl)porphyrin (H 2 T-2-PyP) and meso-tetrakis-(3-pyridyl)porphyrin (H 2 T-3-PyP) were synthesized via Rothmund condensation with use of a modified Adler procedure (Kalyanasundaram, Inorg. Chem. 23:2453 (1984); (Torrens et al, J. Am. Chem. Soc. 94:4160 (1972)). Into a 100 mL refluxing solution of propionic acid were slowly injected equimolar amounts of freshly distilled pyrrole and pyridine-2- or pyridine-3-carboxyladehyde, and the solution was allowed to reflux for about 45 min, after which the propionic acid was distilled off. The black residues were neutralized with NaOH, washed with methanol, dissolved in CH 2 Cl 2 (dichloromethane) and chromotographed on a neutral Woelm alumina column prepared with acetone. After elution of a pale blue fraction, H 2 TPyP was eluted with the use of CH 2 Cl 2 containing 5-10% of pyridine. Shiny dark purple crystals were recovered from the dark red eluant after removal of solvents on rotavaporator. Methylation of H 2 TPyPs was carried using the excess of methyl-p-toluensulfonate in refluxing chloroform (Kalyanasundaram, Inorg. Chem. 23:2453 (1984); (Hambright et al, Inorg. Chem. 15:2314 (1976)). Both of the alkylated porphyrins spontaneously precipitated from hot chloroform solutions and were washed with ether and air dried.
Example II
Preparation of Manganese Complexes of Ortho, Meta and Para Isomers of H 2 TMPyP 4+
The metallation was performed in water at room temperature. The porphyrin to metal ratio was 1:5 in the case of meta and ortho isomers and 1:14 in the case of para isomer. The solid MnCl 2 ×4 H 2 O (Aldrich) was added to the aqueous metal-free porphyrins after the pH of the solution was brought to ˜pH=10.2. The metallation was completed inside an hour in the cases of all three isomers. For the preparation of ortho and meta compounds, MnTM-2-PyP 5+ and MnTM-3-PyP 5+ , 300 mg of the metal-free ligand, either H 2 TM-2-PyP 4+ or H 2 TM-3-PyP 4+ , was dissolved in 100 mL water, pH brought to 10.2 with several drops of 1M NaOH, followed by the addition of 340 mg of MnCl 2 . The metallation was followed spectrally through the disappearance of the Soret band of H 2 TM-2-PyP 4+ or H 2 TM-3-PyP 4+ at 413.3 nm or 416.6 nm, respectively, and the appearance of the Soret bands of manganese complexes at 454.1 nm and 459.8 nm, respectively.
The excess of metal was eliminated as follows for all three (ortho, meta and para) isomers of MnTMPyP 5+ . The MnTMPyP 5+ was precipitated as PF 6 − salt by adding 50-fold excess of NH 4 PF 6 . The precipitate was washed with 2-propanol:diethylether=1:1, and dried in vacuum at room temperature. Dry PF 6 − salt of MnTMPyP 5+ was then dissolved in acetone (370 mg in 100 mL acetone) and 1 g of tetrabutylammonium chloride added. The precipitate was washed with acetone and dried overnight in vacuum at room temperature. In order to obtain a pure compound, the procedure was repeated. The elemental analysis was done for all metallated isomers. The compounds were analyzed in spectral terms and the following data were obtained: Soret bands properties of metallated compounds were: ε 454.1 nm =12.3×10 4 cm −1 M −1 (MnTM-2-PyPCl 5 ), ε 459.8 nm =13.3×10 4 cm −1 M −1 (MnTM-3-PyPCl 5 ), ε 462.2 nm =13.9×10 4 cm −1 M −1 (MnTM-4-PyPCl 5 ).
Metallation was performed in methanol as well. In addition, when performed in water, the metal:ligand ratio varied from 1:5, to 1:14 to 1:100. Under all conditions, the given molar absorptivities were obtained. The calculations were based on the metal-free ligands that were analyzed prior to metallation. The molar absorptivities of the metal-free ligands were consistent with literature as well as their elemental analyses.
The elemental analyses of MnTM2-PyPCl 5 and MnTM-3-PyPCl 5 are shown in Table 1.
TABLE 1
C*
H*
N*
MnTM2-PyPCl 5 .6 H 2 O
52.99 (52.90)
4.85 (4.64)
11.22 (11.21)
MnTM-3-PyPCl 5 .3 H 2 O
55.41 (54.87)
4.97 (4.40)
11.10 (11.69)
*Found (calcd).
Example III
Synthesis of Manganic Meso-tetrakis-(N-ethylpyridinium-2-yl)porphyrin
50 mg of H 2 T-2-PyP was dissolved in 30 mL of anhydrous dimethylformamide (DMF) and the solution was stirred and heated at 100° C. 20 mg of anhydrous MnCl 2 (20 eq) were added and the solution stirred for 3 days. The completion of the metallation was checked by UV spectroscopy. Upon metallation, the temperature was decreased to 60° C., 0.65 mL of iodoethane (100 eq) was added, and the solution was stirred for 7 days (Perree-Fauvet et al, Tetrahedron 52:13569 (1996)). DMF was evaporated, 10 mL of acetone was added, and the product was precipitated adding 20 mL of a solution of TBA in acetone (0.45 M); indeed, contrary to the iodide salt, the chloride salt precipitates in acetone. The product was purified using the “double precipitation” method, as described above. The product was dried overnight in vacuum, over P 2 O 5 , at 70° C., leading to 125 mg (95%) of a dark purple solid. UV (H 2 O), ε 454.0 nm =1.41×10 5 M −1 cm −1 . Elemental analysis, calcd. for MnC 48 N 8 H 44 Cl 5 .5H 2 O: C, (54.64), H, (5.16), N, (10.62); found: C, (54.55), H, (5.36), N, (10.88).
Example IV
Synthesis of Manganic Meso-tetrakis-(N-butylpyridinium-2-yl)porphyrin
The same procedure described above was used. 0.92 mL of 1-iodobutane (100 eq) was added and the mixture stirred at 100° C. for 7 days. Drying of the chloride salt resulted in 70 mg (50%) of a dark purple viscous product. The elemental analysis was thus performed on the hexafluorophosphate salt (non-viscous) The chlorine salt is water-soluble (micelles were not observed). UV(H 2 O) of the chloride salt, ε 454.0 1.21×10 5 M −1 cm −1 . Elemental analysis, calcd. For MnC 56 H 60 N 8P 5 F 30 .H 2 O: C, (40.94), H, (3.80), N, (6.82); found: C, (41.15), H, (4.35), N, (6.52).
Example V
The Ortho Effect Makes Manganic Meso-tetrakis-(N-alkylpyridinium-2-yl)-porphyrin a Powerful Superoxide Dismutase Mimic
The superoxide dismutase activity of the mimetics of the invention depends on a number of factors, including thermodynamic factors (eg the metal-centered redox-potential see FIG. 1 )), and kinetic factors (eg electrostatic facilitation). In an in vitro enzymatic assay of SOD activity (see McCord and Fridovich, J. Biol. Chem. 244:6049 (1969)) the ortho compound “3” proves to be more than an order of magnitude more active than the para compound “1” (see FIG. 2 (note also Table 2 where “2” is the meta compound and “4” and “5” are ortho compounds that carry 4 ethyl or 4 butyl groups, respectively)).
The activity in vivo of the mimetics of the invention can be tested on an E. coli strain deleted of the genes coding for both the MnSOD and FeSOD. In this assay, the efficacy of a mimetic is determined by measuring the effect of the mimetic on the aerobic growth of a SOD null E. coli strain versus a parental strain. Specifically, parental E. coli (AB1157) and SOD null E. coli . (JI132) are grown in M9 medium containing 0.2% casamino acids and 0.2% glucose at pH 7.0 and 37° C.; growth is monitored in terms of turbidity followed at 700 nm. This assay is made more selective for SOD mimetics by omitting the branched chain, aromatic and sulphur containing amino acids from the medium (glucose minimal medium (M9), plus 5 essential amino acids). As shown in FIG. 3 , the increase in activity by the “ortho effect” was confirmed in that, under these growth conditions, SOD null cells cultured in the presence of compound “1” did not show an increase in A 700 while such cells cultured in the presence of compounds “3” and “4” (as well as “2”) did.
The “ortho effect” also decreases the toxicity. It is well known that porphyrins, and particularly cationic porphyrins, interact with DNA and can act as DNA cleavers. This fact can be an issue in the use of metallo-porphyrins as anti-tumor drugs. The present mimetics avoid this interaction. In addition to the increase in activity, the interaction with DNA of the meta “2” and the ortho “3” compounds, is greatly decreased. This is clearly demonstrated by the measurements of the SOD activity in vitro in the presence of DNA (see Table 2), and by the decreased toxicity in vivo ( E. coli ) (see FIG. 3 ).
In order to maximize the decrease in toxicity due to interaction with DNA, two derivatives of the ortho compound have been prepared which carry four ethyl or four butyl groups (“4” and “5”, respectively). The ethyl derivative “4” was significantly less toxic than the methyl derivative “3” (see Table 2 and FIG. 3 ). However, in comparison to the ethylated derivative “4”, the butylated derivative did not show a further decrease in toxicity (see Table 2). These data indicate that ortho ethyl groups are sufficient to inhibit binding of the porphyrin to DNA.
TABLE 2
δ SB (nm)
ε(10 3 )
E ½ (V)
k cat (M −1 s −1 )
DNA-IC 50
1
462.2
139
+0.060
3.8 10 6
7.0 10 −6
2
459 8
133
+0.042
4 1 10 6
2.2 10 −5
3*
454.0
123
4.5 10 7
3.3 10 −5
4*
454.0
141
4.5 10 7
6 7 10 −5
5*
454.0
120
3.0 10 7
6.7 10 −5
Table. UV parameters, redox potential (vs NHE), SOD like activity and DNA interaction parameters of 1, 2, 3 and its atropisomers, 4 and 5 (*mixture of atropisomers, δ SB = Soret band wave-length, ε = molecular absortivity of the Soret band, E ½ = one-electron metal-centered redox-potential, k cat = rate constant for the superoxide dismutation reaction, DNA-IC 50 = concentration of DNA for 50% inhibition of the
# superoxide dismutation reaction).
Example VI
Syntheses and Superoxide Dismutating Activities of Partially (1 to 4) β-Chlorinated Derivatives of Manganese (III) Meso-tetrakis-(N-ethylpyridinium-2-yl)-Porphyrin
Materials and Methods
Materials. 5,19,15,20-Tetrakis-(2-pyridyl)-porphyrin (H 2 T-2-PyP) was purchased from Mid-Century chemicals (Posen, Ill.) (Torrens et al, J. Am. Chem. Soc. 94:4160 (1972)). N-Chlorosuccinimide (NCS), ethyl-p-toluenesulfonate (ETS), tetrabutylammonium chloride (98%) (TBAC), ammonium hexafluorophosphate (NH 4 PF 6 ), manganese chloride, sodium L-ascorbate (99%), cytochrome c, xanthine, ethylenedinitrilotetraacetic acid (EDTA), N,N,-dimethylformamide (98.8%, anhydrous) and 2-propanol (99.5%) were from Sigma-Aldrich. Ethanol (absolute), acetone, ethyl ether (anhydrous), chloroform and dichloromethane (HPLC grade) were from Mallinckrodt, and used without further purification. Xanthine oxidase was supplied by R. D. Wiley (Waud et al, Arch. Biochem. Biophys. 19:695 (1975)). Thin-layer chromatography (TLC) plates (Baker-flex silica gel IB) were from J. T. Baker (Phillipsburg, N.J.). Wakogel C-300 was from Wako Pure Industry Chemicals, Inc (Richmond, Va.).
Instrumentation. Proton nuclear magnetic resonance ( 1 H-NMR) spectra were recorded on a Varian Inova 400 spectrometer. Ultravisible/visible (UV/VIS) spectra were recorded on a Shimadzu spectrophotometer Model UV-260. Matrix-assisted laser desorption/ionization-time of flight—(MALDI-TOFMS) and electrospray/ionization (ESMS) mass spectrometry were performed on a Bruker Proflex III™ and a Fisons Instruments VG Bio-Q triple quadrupole spectrometers, respectively.
H 2 Cl 1 T-2-PyP. 50 mg (8.1×10 −5 moles) of H 2 T-2-PyP was refluxed in chloroform with 43 mg (3.22×10 −4 moles) of NCS (Ochsenbein et al, Angew. Chem. Int. Ed. Engl. 33:348 (1994). The reaction was followed by normal phase silica TLC using a mixture EtOH/CH 2 Cl 2 (5:95) as eluant. After 6 hours of reaction the solution was washed once with distilled water. The chloroform was evaporated and the products of the reaction were chromatographed over 100 g of Wakogel C-300 on a 2.5×50 cm column using the same eluant. The fraction corresponding to H 2 Cl 1 T-2-PyP was purified again using the same system leading to 16 mg of a black purple solid (30%). TLC: R f =0.47. UV/VIS (CHCl 3 ): λ nm (log ε) 419.6 (5.44), 515.2 (4.21), 590.0 (3.72), 645.8 (3.25). MALDI-TOFMS: m/z=654 (M+H + ). 1 H-NMR (CDCl 3 ): δ ppm −2.91 (2H, NH); 7.66-7.74 (m, 4H); 7.99-8.21 (m, 8H); 7.68 (s, 1H); 8.74 (d, 1H, J 6 Hz); 8.76 (d, 1H, J 6 Hz); 8.76 (d, 1H, J 6 Hz); 8.88 (d, 1H, J 6 Hz); 8.90 (d, 1H, J 6 Hz); 8.94 (d, 1H, J 6 Hz); 9.04-9.14 (m, 4H).
H 2 Cl 2a T-2-PyP. The same procedure as described above, leading to 5.3 mg of a black purple solid (10%). TLC: R f =0.50. UV/VIS (CHCl 3 ): λ nm (log ε) 421.4 (5.38), 517.8 (4.21), 591.4 (3.78), 647.6 (3.51). MALDI-TOFMS: m/z=688 (M+H + ). 1 H-NMR (CDCl 3 ): δ ppm −2.98 (2H, NH); 7.66-7.74 (m, 4H); 8.00-8.20 (m, 8H); 8.70 (s, 2H); 8.82 (d, 2H, J 6 Hz); 8.91 (d, 2H, J 6 Hz); 9.06-9.14 (m, 4H).
H 2 Cl 2b+2c T-2-PyP. The same procedure leading to 11 mg of a black purple solid (20%). TLC: R f =0.53. UV/VIS (CHCl 3 ): λ nm (log ε) 421.4 (5.42), 516.8 (4.25), 593.2 (3.74), 646.2 (3.31); MALDI-TOFMS, m/z=688 (M+H + ). 1 H-NMR (CDCl 3 ): δ ppm −3.04 (2H, NH); −2.84 (1H, NH); −2.87 (1H, NH); 7.66-7.74 (m, 8H); 7.98-8.20 (m, 16H); 8.59 (s, 1H); 8.61 (s, 1H); 8.73 (d, 2H, J<2 Hz); 8.78 (d, 2H, J 6 Hz); 8.87 (d, 2H, J 6 Hz); 8.93 (d 2H, J<2 Hz); 9.02-9.14 (m, 8H).
H 2 Cl 3 T-2-PyP. The same procedure using 65 mg (4.87×10 −4 moles) of NCS, leading to 8.4 mg of a black purple solid (14%). TLC: R f =0.55. UV/VIS (CHCl 3 ): λ nm (log ε) 422.8 (5.37), 519.4 (4.21), 593.8 (3.71), 651.4 (3.37). MALDI-TOFMS: m/z=723 (M+H + ). 1 H-NMR (CDCl 3 ): δ ppm −3.08 (1H, NH); −3.15 (1H, NH); 7.66-7.74 (m, 4H); 8.00-8.18 (m, 8H); 8.56 (s, 1H), 8.72 (d, 1H, J 6 Hz); 8.76 (d, 1H, J 6 Hz); 8.82 (d, 1H, J 6 Hz); 8.88 (d, 1H, J 6 Hz); 9.04-9.14 (m, 4H).
H 2 Cl 4 T-2-PyP. The same procedure using 65 mg (4.87×10 −4 moles) of NCS, leading to 7.3 mg of a black purple solid (12%). TLC: R f =0.58. UV/VIS (CHCl 3 ): λ nm (log ε) 423.4 (5.33), 520.0 (4.19), 595.6 (3.66), 651.0 (3.33). MALDI-TOFMS m/z=758 (M+H + ). 1 H-NMR (CDCl 3 ): δ ppm −3.14 (2H, NH); 7.66-7.74 (m, 4H); 7.98-8.16 (m, 8H); 8.74 (d, 4H, J<2 Hz); 9.06-9.12 (m, 4H).
MnTE-2-PyP 5+ . 100 mg (1.62×10 −4 moles) of H 2 T-2-PyP was dissolved in 5 mL of warm DMF (anhydrous), 5.5 mL (3.22×10 −2 moles) of ethyl-p-toluenesulfonate (ETS) was added under stirring at 90° C. and allowed to react for 24-48 hours. The completion of tetra-N-ethylation was followed by normal phase silica TLC using a mixture KNO 3sat /H 2 O/CH 3 CN (1:1:8) as eluant (Batinic-Haberle et al, J. Biol. Chem. 273:24521 (1998)). Upon the completion of the reaction, the DMF was removed in vacuo and 5 mL of acetone was then added. To this solution, a concentrated solution of tetrabutylammonium chloride (TBAC) in acetone (˜1 g/10 mL acetone) was added dropwise under stirring until precipitation of the chloride was complete. The resulting purple solid was dissolved in 10 mL of water, the pH of the solution was raised to 12 with NaOH and 640 mg of MnCl 2 4H 2 O (3.23×10 −3 moles) was added (Batinic-Haberle et al, J. Biol. Chem. 273:24521 (1998). Upon completion of metallation, the pH was lowered between 4 and 7 in order to facilitate the auto-oxidation of Mn(II) into Mn(III), and the excess of metal was eliminated as follows. The solution was filtered, and a concentrated aqueous solution of NH 4 PF 6 was added to precipitate the metalloporphyrin as the PF 6 − salt (Batinic-Haberle et al, Arch. Biochem. Biophy. 343:225 (1997); Richards et al, Inorg. Chem. 35:1940 (1996)). The precipitate was thoroughly washed with a mixture 2-propanol/ethyl ether (1:1), dried in vacuo at room temperature. The resulting solid was then dissolved in acetone and a concentrated solution of TBAC was added to isolate the metalloporphyrin in the form of its chloride salt. The precipitate was washed thoroughly with acetone and dried in vacuo at room temperature leading to 150 mg of a black red solid (95%). TLC: R f =0.18. UV/VIS (H 2 O): λ nm (log ε) 364.0 (4.64), 453.8 (5.14), 558.6 (4.05). ESMS: m/z=157.4 (M 5+ /5). Anal. calcd. for MnC 48 N 8 H 44 Cl 5 .5H 2 O: C, 54.64; H, 5.16; N, 10.62. Found: C, 54.55; H, 5.40; N, 10.39. (See FIG. 4 for compound structures).
MnCl 1 TE-2-PyP 5+ . The same procedure as described above starting from 10 mg (1.53×10 −5 moles) of H 2 Cl 1 T-2-PyP and 0.5 mL (2.94×10 −3 moles) of ETS in 1 mL of DMF. TLC: R f =0.20. UV/VIS (H 2 O): λ nm (log ε) 365.6 (4.63), 455.6 (5.13), 560.6 (4.02). ESMS: m/z=164.3 (M 5+ /5). Anal. calcd. for MnC 48 N 8 H 43 Cl 6 .5H 2 O: C, 52.91; H, 4.90; N, 10.28. Found: C, 52.59; H, 5.28; N, 10.14.
MnCl 2a TE-2-PyP 5+ . The same procedure starting from 5 mg (7.28×10 −6 moles) of H 2 Cl 2a T-2-PyP and 0.25 ml (1.47×10 −3 moles) of ETS, leading to 7.5 mg of a black red solid (95%). TLC: R f =0.21. UV/VIS (H 2 O): λ nm (log ε) 365.8 (4.58), 456.4 (5.05), 562.2 (4.00). ESMS: m/z=171.1 (M 5+ /5). Anal. calcd. for MnC 48 N 8 H 42 Cl 7 .6H 2 O: C, 50.48; H, 4.77; N, 9.81. Found: C, 50.08; H, 4.60; N, 10.01.
MnCl 2b+2c TE-2-PyP 5+ . The same procedure starting from 5 mg (7.28×10 −6 moles) of H 2 Cl 2b+2c T-2-PyP, leading to 7.5 mg of a black red solid (95%). TLC: R f =0.22. UV/VIS (H 2 O): λ nm (log ε) 365.2 (4.63), 457.4 (5.08), 462.2 (4.06). ESMS: m/z=171.1 (M 5+ /5). Anal. calcd. for MnC 48 N 8 H 42 Cl 7 .5H 2 O: C, 51.29; H, 4.66; N, 9.97. Found: C, 51.31; H, 5.19; N, 9.68.
MnCl 3 TE-2-PyP 5+ . The same procedure starting from 5 mg (6.93×10 −6 moles) of H 2 Cl 3 T-2-PyP, leading to 7.5 mg of a black brown solid (95%). TLC: R f =0.23. UV/VIS (H 2 O): λ nm (log ε) 364.8 (4.58), 458.0 (4.98), 466.4 (4.00). ESMS: m/z=178.1 (M 5+ /5). Anal. calcd. for MnC 48 N 8 H 41 Cl 8 .6H 2 O: C, 49.00; H, 4.54; N, 9.52. Found: C, 48.40; H, 4.26; N, 9.59.
MnCl 4 TE-2-PyP 5+ . The same procedure starting from 5 mg (6.61×10 −6 moles) of H 2 Cl 4 T-2-PyP, leading to 7.5 mg of a black brown solid (95%). TLC: R f= 0.24. UV/VIS (H 2 O): λ nm (log ε) 365.8 (4.52), 459.2 (4.90), 567.0 (3.96). ESMS: m/z=184.9 (M 5+ /5). Anal. calcd. for MnC 48 N 8 H 40 Cl 9 .5H 2 O: C. 48.33; H, 4.22; N, 9.39. Found: C, 48.38; H, 4.45; N, 9.53.
Electrochemistry. The electrochemical characterization was performed as described previously on a Voltammetric Analyzer Model 600 (CH instrument) using a glassy carbon electrode (Ag/AgCl reference and Pt auxiliary electrodes), at 0.5 mM porphyrin, pH 7.8 (0.05 M phosphate buffer), 0.1 M NaCl. The potentials were standardized against potassium ferricyanide/potassium ferrocyanide couple (Batinic-Haberle et al, Arch. Biochem. Biophys. 343:225 (1997); Kolthof et al, J. Phys. Chem. 39:945 (1974)).
Superoxide dismuting activity. The SOD-like activities were measured using the xanthine/xanthine oxidase system as a source of O 2 − and ferricytochrome c as its indicating scavenger (McCord et al, J. Biol. Chem. 244:6049 (1969)). O 2 − was produced at the rate of 1.2 μM per minute and reduction of ferricytochrome c was followed at 550 nm. Assays were conducted in presence of 0.1 mM EDTA in 0.05 M phosphate buffer (pH 7.8). Rate constants for the reaction of the compounds were based upon competition with 10 μM cytochrome c, k cyt c =2.6×10 5 M −1 s −1 (Butler et al, J. Biol. Chem. 257:10747 (1982)). All measurements were done at 25° C. Cytochrome c concentration was at least 10 3 -fold higher than the concentrations of the SOD mimics and the rates were linear for at least two minutes, during which the compounds intercepted ˜100 equivalents of O 2 − , thus confirming the catalytic nature of O 2 − dismutation in presence of the mimics.
Results
Despite increasing knowledge on the purification of water soluble porphyrins, the separation of halogenated uncharged porphyrins followed by N-alkylation and metallation still appeared easier for the successful preparation of MnCl x TE-2-PyP 5+ (Scheme A) (Richards et al, Inorg. Chem. 35:1940 (1996); Kaufman et al, Inorg. Chem. 34:5073 (1995)):
Synthesis of H 2 T-2-PyP β-chlorinated derivatives. β-Chlorination of H 2 T-2-PyP was performed as described in the literature for H 2 TPP analogues, using N-chlorosuccinimide (NCS) in chloroform under refluxing conditions (Ochsenbein et al, Angew. Chem. Int. Ed. Engl. 33:348 (1994)). The number of NCS equivalents used can be 4 or 6, depending on the degree of substitution desired (Table 3). The reaction can be followed by TLC (silica gel) using a mixture ethanol/dichloromethane (5:95) as eluant (Table 3 and Scheme B).
TABLE 3
H 2 Cl x T-2-PyP ( x = 1 to 4):
R f , Soret band data and yields with 4 and 6 equivalents of NCS.
Yield (%) c
Porphyrin
R f a
λnm (ε/10 5 M −1 cm −1 ) o
4 eq
6 eq
H 2 T-2-PyP
0.43
418.4
β-Cl 1
0.47
419.6
(2.74)
30
—
β-Cl 2a
0.50
421.4
(2.39)
10
5
β-Cl 2b-2c
0.53
421.4
(2.62)
20
10
β-Cl 3
0.55
422.8
(2.33)
10
15
β-Cl 4
0.58
423.6
(2.13)
7
12
a TLC on silica with EtOH/CH 2 Cl 2 (5.95) as eluant.
o in CHCl 3 (estimated errors for ε are within ±10%).
c in refluxing CHCl 3 during 6 hours (c ˜ 2 μM).
Each compound was purified by chromatography on silica gel (Wakogel C-300) using the same eluant. The structures of the main isomers were identified by mass spectrometry, and UV/VIS and 1 H-NMR spectroscopies (Table 3 and Scheme B). The bathochromic shift of the Soret band per chlorine on H 2 T-2-PyP was only 1.3 nm compared to 3.5 nm reported previously for H 2 TPP derivatives (Table 3) (Hoffmann et al, Bull. Soc. Chem. Fr. 129:85 (1992); Chorghade et al, Synthesis 1320 (1996); Wijesekera et al, Bull. Chem. Fr. 133:765 (1996)). Only one of the three dichlorinated regioisomers (β-Cl 2a derivative) was purified by chromatography on silica gel. Its two other regioisomers (β-Cl 2b and β-Cl 2c derivatives) exhibited the same R f . Preliminary results showed that purification of H 2 Br x T-4-PyP (x=1 to 4) is more difficult. Indeed, using the same TLC system, β-Br 1 and β-Br 2a derivatives both have the same R f , and no difference of R f between β-Br 2b , β-Br 2c , β-Br 3 and β-Br 4 derivatives was observed, showing clearly that, in this case, R f depends on the number of pyrroles substituted and not on the number of β-protons substituted.
1 H-NMR identification of H 2 T-2-PyP β-chlorinated derivatives. 1 H-NMR allowed the identification of the products of the substitution reaction (Table 4 and FIG. 5 ). As described in the literature for H 2 TPP analogues, the main regioisomer of H 2 Cl 4 T-2-PyP has chlorines in positions 7,8,17,18. Indeed, its 1 H-NMR spectrum shows an apparent singlet (doublet with J lower than 2 Hz), corresponding to four chemically equivalent β-protons coupled with the two pyrrolic protons which have lost their delocalization (Crossley et al, J. Chem. Soc., Chem. Commun. 1564 (1991). Nevertheless, another less polar fraction (R f =0.60) was identified, according to its mass spectrum, as a mixture of other tetrachloro-regioisomers ( 1 H-NMR spectrum uninterpretable), representing approximately 50% by weight of both β-Cl 4 fractions, and showing that the β-substitution is only partially regioselective. According to the 1 H-NMR spectrum of the corresponding H 2 Cl 3 T-2-PyP 5+ fraction, there are no apparent other regioisomers. The spectrum presents one singlet corresponding to the β-proton of the monosubstituted pyrrole and four doublets corresponding to the four β-protons of the two non-substituted pyrroles. Moreover, the asymmetry of this compound leads to a differentiation of the two NH protons. According to yields and 1 H-NMR spectra of H 2 Cl 2a T-2-PyP ( FIG. 5 ) and H 2 Cl 2b+2c T-2-PyP, no predominant β-Cl 2 regioisomer was observed. Finally, the H 2 Cl 1 T-2-PyP spectrum shows one singlet and six doublets, but only one NH signal, suggesting that in this case the asymmetry is too weak for the differentiation of the two NH protons.
TABLE 4
H 2 Cl x T-2-PyP (x = 1 to 4): 1 H-NMR
data (porphyrin ring) in CDCl 3
δ ppm (mult., Hz) a
H 2 Cl 1 T-2-PyP
NH
−2.91
(2H)
CH
7.68
(s, 1H)
8.74
(d, 1H, 5.5)
8.76
(d, 1H, 5.5)
8.76
(d, 1H, 6.0)
8.88
(d, 1H, 6.0)
8.90
(d, 1H, 6.0)
8.94
(d, 1H, 6.0)
H 2 Cl 2a T-2PyP
NH
−2.98
(2H)
CH
8.70
(s, 2H)
8.82
(d, 2H, 6 0)
8.91
(d, 2H, 6 0)
H 2 Cl 2b T-2-PyP b
NH
−3.04
(2H)
CH
8.59
(s, 2H)
8.78
(d, 2H, 6.0)
8.87
(d, 2H, 6.0)
H 2 Cl 2c T-2-PyP b
NH
−2.84
(1H)
−2.87
(1H)
CH
8.61
(s, 2H)
8.73
(d, 2H, <2.0)
8.93
(d, 2H, <2.0)
H 2 Cl 3 T-2-PyP
NH
−3.08
(1H)
−3.15
(1H)
CH
8.56
(s, 1H)
8.72
(d, 1H, 6.5)
8.76
(d, 1H, 6.5)
8.82
(d, 1H, 6.5)
8.88
(d, 1H, 6.5)
H 2 Cl 4 T-2-PyP
NH
−3.14
(2H)
CH
8.74
(d, 4H, <2.0)
a chemical shifts in ppm expressed relative to TMS by setting CDCl 3 = 7.24 ppm.
b one spectrum for the mixture of the two regioisomers (˜1:1 ratio).
N-ethylation and metallation. The N-ethylation of H 2 T-2-PyP was efficiently accomplished using ethyl-p-toluenesulfonate, diethylsulfate or iodoethane as reagents, but the high toxicity of diethylsulfate and the low reactivity of iodoethane makes ethyl-p-toluenesulfonate (ETS) the best choice (Chen et al, J. Electroanal. Chem. 280:189 (1990); Kalyamasundaram, Inorg. Chem. 23:2453 (1984); Hambright et al, Inorg. Chem. 15:1314 (1976); Alder et al, Chem. Brit. 14:324 (1978); Perree-Fauvet et al, 52:13569 (1996)). Some authors prefer performing N-alkylation after metallation in order to protect the pyrrole nitrogens (Perree-Fauvet et al, Tetrahedron 52:13569 (1996)). However, with direct treatment on the present free ligands, no N-ethylation of the pyrrole nitrogens was observed (subsequent metallation in aqueous solution was complete). The completion of ethylation as well as metallation can be followed by TLC (normal silica) using a highly polar eluant, a mixture of an aqueous solution of saturated potassium nitrate with acetonitrile (Batinic-Haberle et al, J. Biol. Chem. 273:24521 (1998)). The yields of this step (N-ethylation and metallation) were almost 100% (approximately 5% loss during the purification process). Since N-ethylation (or N-methylation) limits the free rotation of the pyridinium rings, each compound is in fact a mixture of four atropoisomers, and a further purification of each atropoisomer can be considered (Kaufmann et al, Inorg. Chem. 34:5073 (1995)). All the manganese porphyrins prepared had metal in the 3+ state as demonstrated by the 20 nm hypsochromic shift of the Soret band (accompanied by the loss of splitting) upon the reduction of the metal-center by ascorbic acid.
Electrochemistry. The metal-centered redox behavior of all metalloporphyrin products was reversible. The half-wave potentials (E° 1/2 ) were calculated as the average of the cathodic and anodic peaks and are given in mV vs NHE (Table 5). The average shift per chlorine is +55 mV (Table 5), which is in agreement with the values previously reported for H 2 TPP derivatives (between +50 and +70 mV) (Sen et al, Chem. Soc. Faraday Trans. 93:4281 (1997); Autret et al, J. Chem. Soc. Dalton Trans. 2793 (1996); Hariprasad et al, J. Chem. Soc. Dalton Trans. 3429 (1996); Tagliatesta et al, Inorg. Chem. 35:5570 (1996); Ghosh, J. Am. Chem. Soc. 117:4691 (1995); Takeuchi et al, J. Am. Chem. Soc. 116:9730 (1994); Binstead et al, Inorg. Chem. 30:1259 (1991); Giraudeau et al, J. Am. Chem. Soc. 101:3857 (1979)). This shift appears to be higher (˜+65 mV) between 0 and 1, and between 2 and 3 chlorines (Table 5). E° 1/2 values of β-Cl 2a and the mixture β-Cl 2b+2c were not significantly different. The manganese redox state of MnCl 4 TE-2-PyP 5+ (E° 1/2 =+448 mV) and MnOBTMPyP 4+ (E° 1/2 =+480 mV) is 3+ and 2+, respectively. This difference may be explained by their difference in terms of redox potential (˜30 mV) but also by structural considerations, for instance an increased distortion of the porphyrin ring in the case of MnOBTMPyP 4+ . (Batinic-Haberle et al, Arch. Biochem. Biophys. 343:225 (1997); Ochsenbein et al, Angew. Chem. Int. Ed. Engl. 33:348 (1994)).
TABLE 5
MnCl x TE-2-PyP 5− ( x = 1 to 4):
Soret band data, redox potentials and SOD activities.
Mn-porphyrin
λnm (ε/10 4 M −1 cm −1 ) a
E o ½ (Δ) b
IC 50 /10 −9 M c
k cat /10 7 M −1 s −1
MnTE-2-PyP 5−
453.8 (14.0)
+228
(71)
45
5.7
β-Cl 1
455.6 (12.5)
+293
(65)
25
10
β-Cl 2a
456.4 (10.6)
+342
(70)
20
13
β-Cl 2b-2c
457.4 (11.2)
+344
(65)
20
13
β-Cl 3
458.0 (9 5)
+408
(67)
10
26
β-Cl 4
459 2 (8.0)
+448
(79)
6.5
40
MnTM-4-PyP 5−
+060
0.4
MnTM-2-PyP 5−
+220
6.0
MnOBTMPyP 4+
+480
22
Cu,ZnSOD
+260
200
a in H 2 O (estimated errors for ε are within ±10%).
b mV vs NHE, with estimated errors of ±5 mV (Δ = peak to peak separation), and in the following conditions: 0.5 mM porphyrin, 0.1M NaCl, 0.05M phosphate buffer (pH 7.8).
c concentration that causes 50% inhibition of cytochrome c reduction by O 2 − (estimated errors are within ±10%).
Superoxide dismuting activities. SOD-like activities were measured as described previously, based on competition with cytochrome c (McCord et al, J. Biol. Chem. 244:6049 (1969)). MnCl x TE-2-PyP 5+ SOD-like activities are reported in Table 5, IC 50 (M) representing the concentration for one unit of activity (or the concentration that causes 50% inhibition of cytochrome c reduction by O 2 − ) and k cat (M −1 s −1 ) representing the rate constant for the superoxide dismutation reaction. The SOD-like activity per mole of MnCl 4 TE-2-PyP 5+ is approximately 2-, 7- and 100-fold higher than MnOBTMPyP 4+ , MnTM-2-PyP 5+ and MnTM-4-PyP 5+ , respectively (Faulkner et al, J. Biol. Chem. 269:23471 (1994); Batinic-Haberle et al, Arch. Biochem. Biophys. 343:225 (1997); Batinic-Haberle et al, J. Biol. Chem. 273:24521 (1998)). The SOD-like activity of MnCl 4 TE-2-PyP 5+ represents 20% of the activity of the Cu,Zn-SOD enzyme on a molar basis (40% per active site considering that the enzyme has two active sites) (Klug-Roth et al, J. Am. Chem. Soc. 95:2786 (1973)).
Test of stability. Each additional degree of chlorination increases the redox potential which is expected to be followed by the decrease in the pKa values of pyrrole nitrogens, as found for the series of meso-phenyl and meso-pyridyl substituted porphyrins as well as for β-substituted ones (Worthington et al, Inorg. Nucl. Chem. Lett. 16:441 (1980); Kadish et al, Inorg. Chem. 15:980 (1976)). The pKa, as a measure of the ligand-proton stability, is in turn a measure of the metal-ligand stability as well. Thus, the tetrachloro-compound is expected to be of decreased stability as compared to lesser chlorinated analogues. The stability of MnCl 4 TE-2-PyP 5+ was tested by measuring its SOD-like activity in the presence of excess EDTA. In the presence of a 10 2 -fold excess of EDTA, MnCl 4 TE-2-PyP 5+ (c=5×10 −6 M) maintains its activity for sixteen hours (at 25° C.). A loss of activity (˜25%) was observed after forty hours, thus indicating the formation of some manganese—EDTA complex (K=10 14.05 ). These results confirm a relatively good stability of MnCl 4 TE-2-PyP 5+ when compared to MnOBTMPyP 4+ (K=10 8.08 ) (Batinic-Haberle et al, Arch. Biochem. Biophys. 343:225 (1997)).
Relationship between redox properties and SOD-like activities. The Cu,Zn-SOD enzyme is a dimer of two identical subunits, and thus has two active sites, which exhibit a redox potential close to the midpoint of the two half reaction values, as well as the same rate constants for each half reaction (Scheme C and Table 5) (Ellerby et al, J. am. Chem. Soc. 118:6556 (1996); Klug-Roth, J. Am. Chem. Soc. 95:2786 (1973)):
On the other hand, previous studies of O 2 − dismutation catalyzed by MnTM-4-PyP 5+ (E° 1/2 =+60 mV), using pulse radiolysis and stopped flow techniques, showed that the rate of the reduction of the metal by O 2 − is 10 2 -fold to 10 3 -fold lower than the rate of reoxidation of the metal (Faraggi, Oxygen Radicals in Chemistry and Biology, Bors et al (Eds): Walter de Gruyter and Co.; Berlin, Germany 1984, p. 419; Lee et al, J. Am. Chem. Soc. 120:6053 (1998)). Whereas a peak of SOD-like activity somewhere between +200 and +450 mV was first expected, plotting k cat vs E° 1/2 for MnCl x TE-2-PyP 5+ shows an exponential increase of the SOD-like activity, strongly suggesting that the limiting factor is still the reduction of the metal. This hypothesis however must be confirmed by measuring the rates of each half reaction as catalyzed by each MnCl x TE-2-PyP 5+ compound. The relationship between activation free energy (ΔG # ) for superoxide dismutation and free energy change (ΔG°) for MnCl x TE-2-PyP 5+ redox is linear (slope ˜+0.2), clearly showing the predominance of kinetic over thermodynamic factors in the theoretical optimal redox potential region (FIG. 6 ). According to this behavior, the activity of the Cu,Zn-SOD enzyme (k cat =10 9 M −1 s −1 per active site) may be reached at approximately E° 1/2 =+570 mV (FIG. 3 ). However, due to both steric (distortion of the porphyrin ring) and thermodynamic factors, introducing a higher degree of β-chlorination is expected to stabilize the manganese in the 2+ redox state, and thus, as in the case of MnOBTMPyP 4+ , limiting the rate of the reoxidation of the metal as well as inducing Mn(II) dissociation (Batinic-Haberle et al, Arch. Biochem. Biophys. 343:225 (1997); Ochsenbein et al, Angew. Chem. Int. Ed. Engl. 33:348 (1994)).
Example VII
The ortho, meta and para isomers of manganese(III) 5,10,15,20-tetrakis(N-methylpyridyl)porphyrin, MnTM-2-PyP 5+ , MnTM-3-PyP 5+ , and MnTM-4-PyP 5+ , respectively, were analyzed in terms of their superoxide dismutase (SOD) activity in vitro and in vivo. The impact of their interaction with DNA and RNA on the SOD activity in vivo and in vitro was also analyzed. Differences in their behavior are due to the combined steric and electrostatic factors. In vitro catalytic activities are closely related to their redox potentials. The half-wave potentials (E 1/2 ) are +0.220 mV, +0.052 mV and +0.060 V vs normal hydrogen electrode (NHE), while the rates of dismutation (k cat ) are 6.0×10 7 M 1 s −1 , 4.1×10 6 M −1 s −1 and 3.8×10 6 M −1 s −1 for the ortho, meta and para isomers, respectively.
However, the in vitro activity is not a sufficient predictor of in vivo efficacy. The ortho and meta isomers, although of significantly different in vitro SOD activities, have fairly close in vivo SOD efficacy due to their similarly weak interactions with DNA. In contrast, due to a higher degree of interaction with DNA, the para isomer inhibited growth of SOD-deficient Escherichia coli . For details, see Batinic-Haberle et al, J. Biol. Chem. 273(38):24521-8 (Sep. 18, 1998).
Example VIII
Metalloporphyrins are Potent Inhibitors of Lipid Peroxidation
Materials and Methods
L-Ascorbic acid, n-butanol, butylated hydroxytoluene, cobalt chloride, iron(II) chloride, phosphoric acid (85%), sodium hydroxide, potassium phosphate, tetrabutylammonium chloride, and 1,1,3,3-tetramethoxypropane were purchased from Sigma (St. Louis, Mo.). Acetone, concentrated hydrochloric acid, 4,6-dihydroxy-2-mercaptopyrimidine (thiobarbituric acid), NH 4 PF 6 , zinc chloride, 5,10,15,20-tetrakis (4-benzoic acid) porphyrin (H 2 TBAP)*, 5,10,15,20-tetrakis (N-methylpyridinium-4-yl) porphyrin (H 2 TM-4-PyP), and Trolox were purchased from Aldrich (Milwaukee, Wisc.). Ferric 5,10,15,20-tetrakis (4-benzoic acid) porphyrin (FeTBAP) was purchased from Porphyrin Products (Logan, Utah). 5,10,15,20-tetrakis (N-methylpyridinium-2-yl) porphyrin (H 2 TM-2-PyP) was purchased from MidCentury Chemicals (Posen, Ill.). (+)-Rutin was purchased from Calbiochem (La Jolla, Calif.). Manganese chloride was purchased from Fisher (Fair Lawn, N.J.) and ethanol USP was purchased from AAPER Alcohol and Chemical Co. (Shelbville, Ky.). All solutions were prepared in Milli-Q Plus PF water (Millipore, Bedford, Mass.).
* Also known as 5,10,15,20-tetrakis (4-carboxyphenyl) porphyrin (H 2 TCPP)
Preparation and Analysis of Metalloporphyrins
The metalloporphyrins MnTBAP, CoTBAP and ZnTBAP were made using methods described previously (Day et al, J. Pharmacol. Exp. Ther. 275:1227 (1995)). MnTM-4-PyP, CoTM-4-PyP and ZnTM-4-PyP were synthesized by the following method. A 1.5 molar excess of manganese, cobalt or zinc chloride was mixed with H 2 TM-4-PyP that was dissolved in de-ionized water. The reaction mixture was heated to 80° C. and metal ligation was followed spectrophotometrically (UV-2401PC, Shimadzu, Columbia, Md.). Excess metal was removed by passing the mixture through a column containing Bio-Gel P-2 (BioRad, Richmond, Calif.) that selectively retained MnTM-4-PyP. MnTM-4-PyP was eluted with 0.01 N HCl after extensive washing of the column with water. MnTM-4-PyP, CoTM-4-PyP and ZnTM-4-PyP were characterized in terms of their reported Soret bands. The Soret band for MnTM-4-PyP is at 463 nm with an extinction coefficient of (ε)=1.3×10 5 M −1 cm −1 , the Soret band for ZnTM-4-PyP is at 437 nm with an extinction coefficient of (ε)=2.0×10 5 M −1 cm −1 (Pasternack et al, Inorg. Chem. 12:2606 (1973)) and the Soret band for CoTM-4-PyP is at 434 nm with an extinction coefficient of (ε)=2.15×10 5 M −1 cm −1 (Pasternack et al, Biochemistry 22:2406 (1983)). Manganese β-octabromo-meso-tetrakis-(N-methylpyridinium-4-yl) porphyrin (MnOBTM-4-PyP) was synthesized as previously described (Batinic-Haberle et al, Arch. Biochem. Biophys. 343:225 (1997)) and has a Soret band at 490 nm with an extinction coefficient (ε)=8.56×10 4 M −1 cm −1 . H 2 TM-2-PyP was metallated with a 1:20 porphyrin to manganese ratio in water (pH>11) at room temperature. Upon completion of metallation, MnTM-2-PyP was precipitated by the addition of a concentrated aqueous solution of NH 4 PF 6 . The precipitate was washed with 2-propanol:diethyl ether (1:1) and dried in vacuo at room temperature. The PF 6 − salt of MnTM-2-PyP was dissolved in acetone, filtered and a concentrated acetone solution of tetrabutylammonium chloride was added until the porphyrin had precipitated as its chloride salt. The precipitate was washed with acetone and dried in vacuo at room temperature. The Soret band for MnTM-2-PyP was found at 453 nm with an extinction coefficient (ε)=1.29×10 5 M −1 cm −1 .
Preparation of Rat Brain Homogenates
Frozen adult Sprague-Dawley rat brains (Pel-Freez, Rogers, Ariz.) were homogenized with a polytron (Turrax T25, Germany) in 5 volumes of ice cold 50 mM potassium phosphate at pH 7.4. Homogenate protein concentration was determined with the Coomassie Plus protein assay (Pierce, Rockford, Ill.) using bovine serum albumin as a standard. The homogenate volume was adjusted with buffer to give a final protein concentration of 10 mg/ml and frozen as aliquots at −80° C.
Oxidation of Rat Brain Homogenates
Rat brain homogenates (2 mg protein) were incubated with varying concentrations of antioxidant at 37° C. for 15 minutes. Oxidation of the rat brain homogenate was initiated by the addition of 0.1 ml of a freshly prepared anaerobic stock solution containing iron(II) chloride (0.25 mM) and ascorbate (1 mM) as previously reported (Braughler et al, J. Biol. Chem. 262:10438 (1987)). Samples (final volume 1 ml) were placed in a shaking water bath at 37° C. for 30 minutes. The reactions were stopped by the addition of 0.1 ml of a stock butylated hydroxytoluene (60 mM) solution in ethanol.
Lipid Peroxidation Measurement
The concentration of thiobarbituric acid reactive species (TBARS) in rat brain homogenates was used as a index of lipid peroxidation (Bernhem et al, J. Biol. Chem. 174:257 (1948); Witz et al, J. Free Rad. Biol. Med. 2:33 (1986); Kikugawa et al, Anal. Biochem. 202:249 (1992); Jentzsch et all Free Rad. Biol. Med. 20P251 (1996)). Malondialdehyde standards were obtained by adding 8.2 μl of 1,1,3,3-tetramethoxypropane in 10 ml of 0.01 M HCl and mixing for 10 minutes at room temperature. This stock was further diluted in water to give standards that ranged from 0.25 to 25 μM. Samples or standards (200 μl) were acidified with 200 μl of 0.2 M phosphoric acid in 1.5 ml locking microfuge tubes. The color reaction was initiated by the addition of 25 μl of a 0.11M thiobarbituric acid solution and samples were placed in a 90° C. heating block for 45 minutes. TBARS were extracted with 0.5 ml of n-butanol by vortexing samples for 3 minute and chilling on ice for 1 minute. The samples were then centrifuged at 12,000×g for 3 minutes, 150 μl aliquots of the n-butanol phase were placed in each well of a 96-well plate and read at 535 nm in a Thermomax platereader (Molecular Devices, Sunnyvale, Calif.) at 25° C. Sample absorbencies were converted to MDA equivalencies (μM) by extrapolation from the MDA standard curve. None of the antioxidants at concentrations employed in these studies affected the reaction of MDA standards with thiobarbituric acid and reactions without TBA were used as subtraction blanks.
Statistical Analyses
Data were presented as their means ±SE. The inhibitory concentration of antioxidants that decreased the degree of lipid peroxidation by 50% (IC 50 ) and respective 95% confidence intervals (CI) were determined by fitting a sigmoidal curve with variable slope to the data (GraphPad Prizm, San Diego, Calif.).
Results
Comparison of Metalloporphyrins with Other Antioxidants in Iron/Ascorbate-mediated Lipid Peroxidation
The objective of these studies was to investigate whether metalloporphyrins could inhibit lipid peroxidation and to compare their potencies with those of previously characterized antioxidants that include enzymatic antioxidants (SOD and catalase) and non-enzymatic antioxidants (water soluble vitamin E analog, trolox, and plant polyphenolic flavonoid, rutin) (FIG. 7 ). The time course of lipid peroxidation was determined in rat brain homogenates using iron and ascorbate as initiators of lipid oxidation and the formation of thiobarbituric reactive species (TBARS) as an index of lipid peroxidation. A linear increase in the formation of TBARS occurred between 15 to 90 minutes of incubation at 37° C. (FIG. 8 ). Based on this result, an incubation time of 30 minutes was selected to test the ability of metalloporphyrins and other antioxidants to inhibit lipid peroxidation. (FIG. 9 ). Of the agents tested, the manganese porphyrins that have the highest SOD activities, MnOBTM-4-PyP and MnTM-2-PyP, were found to be the most potent lipid peroxidation inhibitors with calculated IC 50 s of 1.3 and 1.0 μM respectively. (Table 6). Bovine CuZnSOD was moderately active with a calculated IC 50 of 15 μM while trolox and rutin were much less potent with calculated IC 50 s of 204 and 112 μM, respectively. In this system, catalase (up to concentrations of 1 mg/ml) did not inhibit iron/ascorbate-initiated lipid peroxidation.
TABLE 6 Comparison of Antioxidant Properties SOD Redox Potential Lipid Peroxidation c Antioxidants (U/mg) a (E ½ , V) b IC 50 [μM] 95% Cl [μM] CuZnSOD 5,100 +0.35 15 13-17 Trolox — — 204 135-308 Rutin — — 113 99-129 MnTM-2-PyP 8,500 +0.22 1.0 0.4-2.2 MnOBTM-4-PyP 18,460 +0.48 1.3 0.8-2.2 MnTM-4-PyP 547 +0.06 16 12-22 MnTBAP 179 −0.19 29 23-37 CoTM-4-PyP 113 +0.42 17 14-22 CoTBAP 24 +0.20 21 13-33 FeTBAP 24 +0.01 212 144-311 ZnTM-4-PyP trace — 241 159-364 ZnTM-2-PyP trace — 591 423-827 ZnTBAP trace — 843 428-1660 a Unit of SOD activity defined as the amount of compound that inhibits one half the reduction of cytochrome c or photoreduction of NBT. b Metal centered redox potentials vs NHE (Mn +3 /Mn +2 ; Co +3 /Co +2 ; Fe +3 /Fe +2 ). If not otherwise specified, E ½ were obtained at pH 7.8. c The amount of thiobarbaturic acid reactive substances produced in a rat brain homogenate by 30 minutes of incubation of iron and ascorbate.
Effect of Different Metal Chelates on the Ability of Porphyrins to Inhibit Lipid Peroxidation
A wide range of metals can be covalently ligated by porphyrins and that confers different redox potentials and SOD activities (Table 6). The ability of different metal chelates to influence a porphyrin's ability to inhibit lipid peroxidation was tested. Several different metal analogs of TBAP were examined in the iron/ascorbate-initiated lipid peroxidation model (FIG. 10 ). Both the manganese and cobalt TBAP analogs had similar efficacy with calculated IC 50 of 29 and 21 μM, respectively. The FeTBAP analog was an order of magnitude less potent with a calculated IC 50 of 212 μM. The ZnTBAP analog was much less active than the other metal analogs with a calculated IC 50 of 946 μM. This potency difference between the zinc and the other metals reflects the importance of metal centered verses ring structure redox chemistry since zinc can not readily change its valence. The ranked potencies of tested metalloporphyrins based on IC 50 s were as follows: MnTM-2-PyP=MnOBTM-4-PyP>MnTM-4-PyP=CoTM-4-PyP>CoTBAP=MnTBAP>FeTBAP=ZnTM-4-PyP>ZnTM-2-PyP>ZnTBAP.
Comparison of a Series of Tetrakis N-methylpyridyl Porphyrin (TMPyP) Analogs as Inhibitors of Lipid Peroxidation
Recently, several manganese analogs of N-methylpyridyl porphyrins have been found to possess large differences in SOD activities (Table 6). MnTM-2-PyP and MnTM-4-PyP differ structurally with respect to the position of the N-methylpyridyl group to the porphyrin ring (ortho vs para) as well as in SOD activity by a factor of six. Substitution of zinc in these porphyrin analogs results in loss of SOD activity. These TMPyP analogs were compared for their ability to inhibit lipid peroxidation (FIG. 11 ). The movement of the N-methylpyridyl group from the para- to the ortho-position in the manganese porphyrin resulted in a 15-fold increase in potency. Since MnTM-2-PyP possesses a more positive redox potential than MnTM-4-PyP (+0.22 vs +0.06, respectively), this data suggests that both the redox potential and the related SOD activity may contribute to the increased potency of the MnTM-2-PyP analog.
Example IX
Demonstration that Mn TE-2-PyP can be Effectively Used to Attenuate Oxidant Stress Mediated Tissue Injury
The ability of Mn TE-2-PyP to attenuate injury associated with 60 minutes of global ischemia followed by 90 minutes of reperfusion was assessed in an isolated, perfused mouse liver model. Excised livers were perfused with a buffered salt solution for 15 minutes after which the metalloporphyrin was introduced into the perfusate and the liver perfused in a recirculating system for an additional 15 minutes. The livers were then rendered globally ischemic under normal thermic conditions for 60 minutes. Following the ischemic period the livers were perfused for 90 minutes with perfusate supplemented with 10 μm Mn TE-2-PyP. In this model the ischemia/reperfused livers have a marked release of hepatocellular enzymes, aspartate transaminase, alanine transaminase, and lactate dehydrogenase during the first 2½ minutes of reperfusion. This is followed by a progressive release of hepatocellular enzymes indicating hepatocellular injury over the 90 minute perfusion period. Administration of Mn TE-2-PyP was highly efficacious in attenuating the liver injury, blocking virtually all of the acute hepatocellular enzyme release and blocking progressive hepatocellular enzyme release over the 90 minute perfusion period. At the end of the experiments liver is treated with the metalloporphyrin. It has demonstrated excellent oxygen consumption and a normal perfusion pattern. They remain firm and with a normal texture to gross morphologic examination. Livers with no drug treatment did not consume oxygen normally and became edematous, soft, and had a mottled appearance consistent with poor perfusion.
Example X
Effects of Mn TM-2-PyP on Vascular Tone
Rats were anesthetized and a femoral vein and carotid artery were cannulated. While blood pressure was monitored by the carotid artery, Mn TM-2-PyP was injected i.v. at doses ranging from 0.1 to 3.0 mg/kg. Mean arterial pressure fell from 100-125 mmHg to 50-60 mmHg within five to ten minutes. The effect was transient, lasting up to 30 minutes at doses of 0.1 to 0.25 mg/kg. At doses of 1-3 mg/kg the effect was prolonged, lasting up to two hours. The effect can be blocked by administration of inhibitors of nitric oxide synthase demonstrating that the role of Mn TM-2-PyP is being modulated by nitric oxide. Scavenging of superoxide in vascular walls would potentiate the effects of nitric oxide producing hypotension.
Example XI
Regulation of Airway Reactivity Using Mn TM-2-PyP
Mice were sensitized by intraperitoneal injection of ovalbumin twice, 14 days apart. Fourteen days after the second i.p. injection they were challenged with aerosolized ovalbumin daily for three days. Forty-eight hours after the third inhalation of ovalbumin they were given a 1 minute methacholine challenge and airway hyperreactivity followed using a Buxco body plethysmograph. Significant increases in airway resistance as measured by the PENH index occurred at doses of 20, 30 and 40 mg/ml of methacholine. At all doses of methacholine prior intratracheal instillations of 2 μg Mn TM-2-PyP given daily for 4 days resulted in a statistically significant reduction in the airway hyperreactivity. This dose of Mn TM-2-PyP is equivalent to 0.8 mg/kg whole body dose.
Example XII
Treatment of Bronchopulmonary Dysplasia Using Mn TE-2-PyP
Neonatal baboons were delivered prematurely by Caesarian section and then treated either with 100% oxygen or only sufficient PRN FIO 2 to maintain adequate arterial oxygenation. To establish the model, thirteen 100% oxygen treated animals and twelve PRN control animals were studied. Treatment with 100% oxygen results in extensive lung injury manifested by days 9 or 10 of exposure and characterized by delayed alveolarization, lung parenchymal inflammation, and poor oxygenation. This is characteristic of the human disease, bronchopulmonary dysplasia and is thought to be mediated, at least in part, by oxidative stress on the developing neonatal lung. In a first trial of Mn TE-2-PyP, a neonatal baboon was delivered at 140 days gestation and placed in 100% oxygen. The animal received 0.5 mg/kg/24 hr Mn TE-2-PyP qd given i.v. in a continuous infusion over the entire 10 day study period. This animal showed marked improvement of the oxygenation index. There was no evidence of clinical decompensation of the lungs at days 9 and 10. Lung pathology demonstrated absence of inflammation and a marked decrease in the lung injury found in the prior animals treated with 100% oxygen under identical conditions. This suggests that Mn TE-2-PyP can be used to treat oxidant stress in the premature newborn.
All documents cited above are hereby incorporated in their entirety by reference. Application Ser. No. 60/064,116, filed Nov. 3, 1997, is also incorporated in its entirety by reference.
One skilled in the art will appreciate from a reading of this disclosure that various changes in form and detail can be made without departing from the true scope of the invention. | The present invention relates, in general, to a method of modulating physiological and pathological processes and, in particular, to a method of modulating cellular levels of oxidants and thereby processes in which such oxidants are a participant. The invention also relates to compounds and compositions suitable for use in such methods. | 2 |
RELATED APPLICATION INFORMATION
[0001] This application claims priority to Patent Cooperation Treaty Application Number PCT/EP2005/056316 filed Nov. 29, 2005, which claims priority to German Application DE 20 2004 018 469.9 filed Nov. 29, 2004, both of which contents are incorporated herein by reference.
NOTICE OF COPYRIGHTS AND TRADE DRESS
[0002] A portion of the disclosure of this patent document contains material which is subject to copyright protection. This patent document may show and/or describe matter which is or may become trade dress of the owner. The copyright and trade dress owner has no objection to the facsimile reproduction by anyone of the patent disclosure as it appears in the Patent and Trademark Office patent files or records, but otherwise reserves all copyright and trade dress rights whatsoever.
BACKGROUND
[0003] 1. Field
[0004] This disclosure relates to a low temperature cryostat.
[0005] 2. Description of the Related Art
[0006] It is conventional to make use in low temperature microscopy of sample tubes in which the respective microscope is arranged. The sample tubes are inserted into 4K cryostats and cooled by means of liquid nitrogen (77K) and liquid helium (4K). A so-called dipstick with a sample to be examined and a microscope is inserted into the sample tube and cooled. The sample tube itself can in this case be evacuated or be filled with exchange gas for the purpose of better thermal coupling to the liquid nitrogen and the liquid helium.
[0007] FIG. 6 shows such a conventional arrangement having a cryostat vessel 302 that is evacuated. A cooling device 304 and a microscopy device 306 are arranged in the cryostat vessel 302 . The cooling device 304 comprises a nitrogen cooler 310 with liquid nitrogen as coolant. The nitrogen cooler 310 is connected to a 70K cold shield 314 via a thermal 70K coupling 312 . Arranged concentrically in the nitrogen cooler 310 with 70K cold shield 314 is a helium cooler 320 that is thermally coupled to a 4K cold shield 324 via a 4K coupling 322 . A sample tube 330 is arranged concentrically relative to the helium cooler 320 with 4K cold shield 322 , and relative to the nitrogen cooler 310 with 70K cold shield 314 . The thermal connection between the sample tube 330 and the nitrogen cooler 310 and/or the helium cooler 320 is performed by a mechanical, and therefore thermal connection of the sample tube 330 to the 70K coupling 314 and/or the 4K coupling 324 . A sample rod or dipstick 332 is inserted into the sample tube 330 , and a confocal microscope 334 is arranged at its lower end.
[0008] Cooling with the aid of liquid nitrogen and liquid helium is disadvantageous in this known apparatus, since handling liquid nitrogen and liquid helium is complicated and awkward. Moreover, the use of liquid helium is expensive.
[0009] It is therefore an object of the present invention to specify a low temperature cryostat that is easier to handle and more cost-effective in operation.
[0010] This object is achieved by means of a low temperature cryostat in accordance with the features of claim 1 .
[0011] Further details, features and advantages of the invention emerge from the following description of preferred embodiments of the invention with the aid of the drawings, in which:
DESCRIPTION OF THE DRAWINGS
[0012] FIG. 1 shows a schematic of a first embodiment of the invention having a single-stage pulse tube cooler;
[0013] FIG. 2 shows a second embodiment of the invention having a two-stage pulse tube cooler;
[0014] FIG. 3 shows a detailed illustration of the confocal microscope of the second embodiment of the invention having a piezo positioning apparatus;
[0015] FIG. 4 shows a detailed illustration, corresponding to FIG. 3 , of a third embodiment of the invention having an atomic force or scanning tunneling microscope instead of the confocal microscope;
[0016] FIG. 5 shows a fourth embodiment of the invention having a ADR cooling stage, a 100 mK cooling stage and a confocal microscope;
[0017] FIG. 6 shows a low temperature cryostat according to the prior art.
DETAILED DESCRIPTION
[0018] Throughout this description, the embodiments and examples shown should be considered as exemplars, rather than limitations on the apparatus and methods disclosed or claimed.
[0019] Since it is impermissible in low temperature microscopy to transmit vibrations onto the sample, there has so far been no use of mechanical cooling devices such as compressors and pulse tube coolers. Compressor cooling devices have a broad spectrum of vibrations from the low frequency up to the high frequency range, and are therefore unsuitable as a replacement for nitrogen/helium coolers. Given appropriate design, pulse tube coolers can certainly be configured because of vibration, but their functionality dictates that they have vibrations in the low frequency 1 Hz range that cannot be eliminated. These vibrations originate from the oscillating gas column in the pulse tube cooler. These vibrations cause a deflection of the cold head of the pulse tube cooler in the □m region. The use of pulse tube coolers has so far been refrained from because of these vibrations that cannot be eliminated. However, it has been shown that when use is made of pulse tube coolers these low frequency vibrations are by far less disturbing than assumed. This is likely to be ascribed to the fact that the microscope device connected to the cold head covibrates synchronously because of the low frequencies, and this oscillation is therefore not disturbing.
[0020] In accordance with an advantageous refinement of the invention, the component of a pulse tube cooler that still most readily also generates high frequency vibrations in addition to the low frequency vibrations, specifically the turning valve, is arranged outside the cryostat vessel and is connected to the latter by means of a flexible hose line. This prevents the high frequency vibrations from impairing the mode of operation of the microscopy device, and at the same time the low frequency vibrations are reduced. Consequently, it is only the low frequency vibrations that still occur in the cryostat vessel on the basis of the oscillating gas.
[0021] In accordance with a further preferred refinement of the invention, the thermal coupling of the microscopy device to the pulse tube cooling system is designed in an elastic and vibration damping fashion. Consequently, the low frequency vibrations still occurring from the pulse tube cooling system are strongly damped and are therefore less able to have a disturbing effect on the microscopy device. Moreover, account is thereby taken of the unavoidable changes in length between ambient temperature and the temperature of the sample.
[0022] Such a low temperature cryostat can be used with a multiplicity of different microscopy devices such as confocal microscope, tunneling microscope, atomic force microscope, magnetic microscope, chemical microscope etc.
[0023] The remaining subclaims relate to further advantageous refinements of the invention.
[0024] FIG. 1 shows a schematic of the essential components of a first embodiment of the invention, in the case of which the basic concept of the invention is concerned. A cooling device 4 in the form of a single-stage pulse tube cooler 10 is arranged in a cryostat vessel 2 . The pulse tube cooler 10 comprises a pulse tube 12 and a regenerator 14 that are arranged between a cold head 16 and a valve head 18 . A microscopy device 6 is mechanically and thermally coupled to the cold head 16 by means of a thermal coupling 8 .
[0025] FIG. 2 shows a second embodiment having a cryostat vessel 102 , a cooling device 104 , arranged in the cryostat vessel 102 , in the form of a two-stage pulse tube cooling system 110 . The pulse tube cooling system 110 has a first pulse tube cooler 111 and a second pulse tube cooler 121 . The first pulse tube cooler 111 has a first pulse tube 112 and a first regenerator 113 . The first pulse tube 112 and the first regenerator 113 are arranged between a valve head 114 and a 60K cold head 115 . The second pulse tube cooler 121 has a second pulse tube 122 and a second regenerator 123 . The second pulse tube 122 is arranged between the valve head 114 and a 4K cold head 125 , and the second regenerator 123 is arranged between the 60K cold head 115 and the 4K cold head 125 . A ballast volume 116 is directly connected to the valve head 114 arranged outside the cryostat vessel 102 . The valve head 114 and the ballast volume 116 are connected to a turning valve 118 via a flexible hose 117 .
[0026] Arranged in the cryostat vessel 102 is a sample tube 130 that is accessible from the outside and into which a sample rod 132 can be inserted. The sample rod 132 has a warm end 134 , which projects from the cryostat vessel 102 , and a cold end 136 , which comes to lie in the interior of the cryostat vessel 102 . A confocal microscope 138 is arranged in the region of the cold end 136 of the sample rod 132 .
[0027] The sample tube 130 , and thus the sample rod 132 with the confocal microscope 138 are connected thermally to the 60K cold head 115 via a 60K coupling 140 , and to the 4K cold head 125 of the cooling device 104 via a 4K coupling 142 . The 60K coupling 140 is arranged closer at the warm end 134 , and the 4K coupling 142 is arranged in the region of the cold end 136 . The sample rod 132 is arranged concentrically in the sample tube 130 . The sample tube 130 has a hollow cladding 144 that can be evacuated or filled with exchange gas.
[0028] Owing to the spatially separated arrangement of the turning valve and its connection to the valve head via a flexible hose 117 , vibrations of the turning valve 118 are strongly damped, and scarcely any vibrations are transmitted onto the cryostat vessel. Owing to the configuration of the 60K coupling 140 and of the 4K coupling 142 in the form of an elastic strip made from material that effectively conducts heat, vibrations from the pulse tube cooling system are likewise strongly damped, and so scarcely any vibrations are transmitted onto the sample tube 130 , and thus onto the confocal microscope 138 . A braided ground strap made from electrolytic copper is well suited therefor.
[0029] FIG. 3 shows a detail of the third embodiment of the invention, specifically the cold end 136 of the sample rod 132 with the confocal microscope 138 . The confocal microscope 138 comprises a lens arrangement 146 that is thermally and mechanically connected to the 4K coupling 142 by means of a piezo positioning apparatus 148 . A sample 150 to be examined is arranged below the lens arrangement 146 . The light that originates from a light source (not illustrated), is reflected by the sample 150 and falls into the lens arrangement 146 is guided out of the cryostat vessel 102 via an optical fiber 152 . The viewing light is preferably likewise coupled in via the optical fiber 152 . The focusing of the lens arrangement 146 is performed by the piezo apparatus 148 . The lens arrangement 146 can be moved and positioned on three spatial axes relative to the sample 150 with the aid of the piezo positioning apparatus 148 . The entire arrangement is surrounded by a cladding 154 that is part of the sample rod 132 .
[0030] FIG. 4 shows a detail of a third embodiment of the invention, in the case of which instead of a confocal microscope an atomic force or scanning tunneling microscope 160 is provided in the cryostat design according to FIG. 2 . Components are correspondingly provided with the same reference numerals in FIGS. 3 and 4 . The third embodiment of the invention differs from the second embodiment only in that a carrier unit 162 for a scanning tip 164 is provided instead of the lens arrangement 146 , and an electric signal line 166 is provided instead of the light guide 152 .
[0031] FIG. 5 shows a fourth embodiment of the invention having a cryostat vessel 202 in which a cooling device 204 is accommodated. The cooling device 204 arranged in the cryostat vessel 202 comprises a two-stage pulse tube cooling system 210 having a first pulse tube cooler 211 with a first cold head 215 , and a second pulse tube cooler 221 with a second cold head 225 . The interface to the outside is provided via a valve head 214 . The remaining components such as turning valve and ballast volume, for example, are not illustrated. The two-stage pulse tube cooling system 210 comes close to the pulse tube cooling system from FIG. 2 . The two-stage pulse tube cooling system 210 precools an adiabatic demagnetization cooling stage or an ADR cooling stage 205 , having a magnet that is not, illustrated, to approximately 4K. The ADR stage 205 is thermally and mechanically coupled to the second cold head 225 of the two-stage pulse tube cooling system 210 The confocal microscope 238 with positioning apparatus (not illustrated) is arranged at the magnet (not illustrated) of the ADR cooling stage 205 . The confocal microscope 238 is thereby thermally coupled to the second cold head 225 and is cooled to approximately 4K. The ADR cooling stage 205 cools to approximately 100 mK. A sample 208 is thermally coupled to the ADR cooling stage 205 via a sample holder 206 , such that the sample is cooled to approximately 100 mK.
[0032] The above-described embodiments of the invention may also be combined with one another. It is likewise possible, for example, to arrange a number of different microscopes in the cryostat vessel.
LIST OF REFERENCE NUMERALS
[0000]
2 Cryostat vessel
4 Cooling device
6 Microscopy device
8 Thermal coupling
10 Pulse tube cooler
12 Pulse tube
14 Regenerator
16 Cold head
18 Valve head
102 Cryostat vessel
104 Cooling device
110 Two-stage pulse tube cooling system
111 First pulse tube cooler
112 First pulse tube
113 First regenerator
114 Valve head
115 60K cold head
116 Ballast volume
117 Flexible hose
118 Turning valve
121 Second pulse tube cooler
122 Second pulse tube
123 Second regenerator
125 4K cold head
130 Sample tube
132 Sample rod
134 Warm end of 132
136 Cold end of 132
138 Confocal microscope
140 60K coupling
142 4K coupling
144 Cladding of 130
146 Lens arrangement
148 Piezo apparatus
150 Sample
152 Optical fiber
160 AFM or scanning tunneling microscope
162 Carrier unit for 164
164 Scanning tip
166 Electric signal line
202 Cryostat vessel
204 Cooling device
205 ADR cooling stage
206 Sample holder
208 Sample
210 Two-stage pulse tube cooling system
211 First pulse tube cooler
214 Valve head
215 First cold head
221 Second pulse tube cooler
225 Second cold head
238 Confocal microscope
302 Cryostat vessel
304 Cooling device
306 Microscopy device
310 Nitrogen cooler
312 70K coupling
314 70K cold shield
320 Helium cooler
322 4K coupling
324 4K cold shield
330 Sample tube
332 Sample rod (dipstick)
Closing Comments
[0097] The foregoing is merely illustrative and not limiting, having been presented by way of example only. Although examples have been shown and described, it will be apparent to those having ordinary skill in the art that changes, modifications, and/or alterations may be made. | A low temperature cryostat is disclosed. The low temperature cryostat may include a cryostat vessel, a cooling device arranged in the cryostat vessel for producing a cooling temperature level, a microscopy device for examining a sample, and at least one thermal coupling for thermally and mechanically connecting the microscopy device to the cooling device. The cooling device may comprise a pulse tube cooling system. | 5 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a substrate fastener to be fitted on substrates of printed circuit boards or chassis of electronic instruments or appliances for connecting or fixing a plural number of substrates substantially at right angles or at an askew angle to each other.
2. Description of the Prior Art
For example, substrates of printed circuits which are erected in upright positions on a chassis of an electronic instrument are usually connected by directly soldering their circuits or by the use of a connector. When mounting printed circuit boards in such upright positions, it has been the conventional practice to fix a large substrate retainers 21 opposingly on a horizontal substrate by means of screws and to hold side edge portions of the upright substrate in the grooves on the inner side of the substrate retainers. Therefore, stability of the vertical substrates depends upon the width and height of the retainers, as a result, it is necessary to use retainers of a large size. Use of large retainers limits the number of elements of vertical substrates which can be mounted on a horizontal substrate, or, namely, the packaging density of printed circuit boards which can be mounted on a horizontal substrate.
SUMMARY OF THE INVENTION
With the foregoing situations in view, the present invention has the provision of a substrate fastener which can overcome the above-mentioned problems or difficulties and which is arranged in the manner as follows.
Namely, according to the present invention, there is provided a substrate fastener which is provided with resilient coupling members on opposite ends of a strut member, the resilient coupling members being resiliently engageable in mounting holes provided in substrates to be connected, and one or both of the resilient coupling members being secured to the strut member through a flexible hinge of a synthetic resin material.
Since the substrate fastener has a resilient coupling member or members flexibly attached to strut member through the flexible hinge as mentioned above, it is possible to fit the resilient coupling members in mounting holes in the horizontal and vertical substrates at an askew angle with the respective substrates, which are connected to the other ends by means for suitable connecting. Thus, the two substrates can be supported at a right angle or at an arbitrary angle with each other by the round member. When the means for connecting at the other end of one substrate is removed, its freed end can be turned about the hinge of a synthetic resin to assume an arbitrary angular position relative to the other substrate thereby to facilitate repair or inspection of the printed circuit. In addition, since the substrate fastener can be used as a small diagonal strut, it occupies only small areas on the substrates, permitting to mount electronic elements on the substrates in higher density.
The above and other objects, features and advantages of the invention will become apparent from the following description and the appended claims, taken in conjunction with the accompanying drawings which show by way of example some preferred embodiments of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
In the accompanying drawings:
FIG. 1 is a front view of a substrate fastener according to the invention;
FIG. 2 is a side view of the fastener of FIG. 1;
FIG. 3 is a side view of the fastener in use;
FIG. 4 is a view similar to FIG. 3 but showing the fastener used in a different manner;
FIG. 5 is a front view of a second embodiment of the invention; and
FIG. 6 is a front view of a third embodiments of the invention.
DESCRIPTION OF PREFERRED EMBODIMENTS
Hereafter, the invention is described more particularly by way of the preferred embodiments shown in the drawings.
Referring to FIGS. 1 and 2, there is shown a first embodiment of the invention in front and side views, wherein indicated at 1 is a rod-like strut member which is provided with a resilient coupling member 3 at the opposite ends thereof through a flexible hinge 4 of a synthetic resin material, the resilient coupling member 3 each having a resilient support portion 2 in a base portion thereof. The flexible hinge 4 is in the form of a plate-like synthetic resin material capable of elastic deformation. Formed at the fore end of the flexible hinge 4 is a resilient support member 2 which has resilient support strips 2a protruded from the opposite sides in direction away from each other. Provided at the outer end of the resilient support member 2 is the resilient coupling member 3 to be fitted in a mounting hole of a printed circuit board or the like by elastic deformation, and locked therein by spreading its arm portions which are protruded on the other side of the printed circuit board. Namely, the resilient coupling member 3 includes a stem portion which is extended out from a center portion of the resilient support member 2, arm portions which are extended toward the resilient support member 2 from the free end of the stem, and thin wall portions which connect the fore end portions of the arms with the resilient support member 2.
The substrate fastener of the above-described construction is integrally formed of a resilient synthetic resin material such as nylon or the like, and, for example, the resilient coupling members 3 are fitted in mounting holes in corner portions of horizontal and vertical substrates 10 and 11 which are disposed substantially at a right angles to each other as shown in FIG. 3, securely connecting the vertical substrate 11 to the horizontal substrate 10 by diagonally disposed strut member 1. That is to say, the resilient coupling member 3 at the upper end of the fastener is first fitted in the mounting hole of the vertical substrate 11 which is held in upright state on the horizontal substrate 10, and then the resilient coupling member 3 at the lower end of the fastener is fitted in the mounting hole in the horizontal substrate 10. At this time, marginal edge portions of the respective mounting holes are gripped between the resilient support strips 2a of the resilient support members 2 and the coupling members 3. The strut member 1 is disposed at the angle of about 45 degrees, while the resilient coupling members 3 at the opposite ends of the strut member 1 are held at the angle of about 135 degrees with the strut 1 by the flexible hinges 4. On the other hand, the upper end of the vertical substrate 11 is gripped in a gripping portion 13a at one end of an end gripper 13 which is fitted at the other end in another vertical substrate 12, thereby holding the vertical substrate 11 in upright state.
Thus, the vertical substrate 11 is fixedly supported on the horizontal substrate 10 in a simple and secure manner. In a case where there arises a necessity for turning the vertical substrate 11 into a horizontal position for repair or insepction, the vertical substrate 11 can be easily turned upon removing the gripping portion of the end gripper 13 from its end, permitting to assume a horizontal position as shown in phantom line in FIG. 3 or other inclined positions, by means of the flexible hinge 4.
Illustrated in FIG. 4 is an example of connecting a horizontal substrate 15 on another horizontal substrate 14 in spaced relationship with each other by use of the above-described substrate fastener of the invention. In this case, the resilient coupling member 3 at the upper end is fitted in a mounting hole of a vertical substrate 16, fitting the other resilient coupling member 3 at the lower end of the fastener in a mounting hole of the horizontal substrate 15. Similar to the above-described case, the resilient coupling members 3 at the opposite ends of the fastener are bent to an angle of about 45 degrees with the strut member 1 by the flexible action of the synthetic resin hinge 4, the strut member 1 which is disposed at an angle of about 45 degrees holding the upper horizontal substrate 15 in a horizontal position relative to the vertical substrate 16. The fore end of the horizontal substrate 15 is held in a gripping portion 17a of an end gripper 17 which is fixedly mounted on the lower horizontal substrate 14, supporting the horizontal substrate 15 spacedly over the lower horizontal substrate 14. In a manner similar to the above-described fastener, this substrate fastener can also be bent at the flexible resin hinge 4 and turned easily into a vertical position upon releasing its end from gripping portion of the end gripper 17.
FIG. 5 illustrates a second embodiment of the invention, which is same as the foregoing embodiments in construction and operation except that the substrate fastener is provided with arcuate resilient support members 5 instead of the above-described resilient support members 2 at the opposite ends of a round rod-like flexible hinge 4 formed of synthetic resin 4.
Shown in FIG. 6 is a third embodiment of the invention, wherein resilient coupling members 9 are connected to the opposite ends of a strut member 1 through the flexible hinges 7 of synthetic resin 7 and in tilted state, forming an angle of about 45 degrees with the strut member. The resilient coupling members 9 are provided with small resilient support strips 8 at the base portions thereof. When the strut member 1 of the substrate fastener is placed in a corner portion between horizontal and vertical substrates diagonally at an angle of 45 degrees as shown in FIGS. 3 and 4, the laterally and downwardly facing the resilient coupling members 9 can be easily fitted in mounting holes in the vertical and horizontal substrates, respectively. Further, if the end portion of the horizontal or vertical substrate is freed from the end gripper, the substrate can be turned about the flexible hinge 7 of synthetic resin 7 to assume an arbitrary angular position in the same manner as described hereinbefore.
Although the flexible hinges are provided at both ends of the strut with the resilient coupling members, it is of course possible to provide the flexible hinge only at one end of the strut member if desired. | Described herein is a substrate fastener having resilient coupling members at the opposite ends of a strut member, characterized in that the coupling members are resiliently engageable in mounting holes of substrates to be fastened to each other, and at least one of the coupling members is connected to the strut member through a flexible hinge of a synthetic resin material. Accordingly, the fastener occupies only small areas on the substrates, permitting to mount electronic parts on the substrates in higher packaging density. The connected substrates can be freely turned into a horizontal or vertical position if desired. | 8 |
[0001] This application is a divisional application of pending U.S. application Ser. No. 11/893,264, filed Aug. 15, 2007 (of which the entire disclosure of pending, prior application is hereby incorporated by reference), now abandoned, which in turn, is a continuation application of application Ser. No. 10/286,107, filed Oct. 31, 2002, now abandoned.
FIELD OF THE INVENTION
Background of the Invention
[0002] Synthetic fibers fabricated primarily from polyamide, polyester, vinylon, polyolefin, etc. are now used as industrial synthetic fibers for fishery, agricultural, and construction uses, because improved tenacity and weatherproof are demanded in such applications. For lack of self-degradability, however, such synthetic fibers, if left undisposed at hills and fields and in the sea after use, offer problems that not only are they detrimental to landscapes, but also they cling to birds, oceanic life, divers or the like, killing them or to marine engines, leading to shipwrecks. These problems may be solved if used-up synthetic fibers are disposed by incineration, landfilling or regeneration; however, they are still left undisposed at hills and fields or in the sea because much labor and cost are taken for such disposals. To provide a solution to those problems, the use of synthetic fibers fabricated from biodegradable polymers is now taken up for consideration, and so a variety of biodegradable synthetic fibers are under development. In particular, efforts are focused on making fibriform lactic acid polymers because they are biodegradable polymers from which articles having practical mechanical properties and heat resistance can be formed at relatively low costs. The present invention relates to improvements in an agent and method for treating biodegradable synthetic yarns fabricated from lactic acid polymers.
[0003] For agents for treating biodegradable synthetic yarns fabricated from lactic acid polymers, there have so far been proposed (1) an agent comprising water, ethylene glycol, polyethylene glycol, silicone oil, etc. (JP-A's 10-110332 and 2000-154425), (2) an agent in which mineral oil lubricants are used as a lubricant (JP-A 2000-192370), and (3) an agent comprising an anionic surfactant such as potassium laurylphosphate, an cationic surfactant such as a quaternary ammonium salt, a nonionic surfactant such as an aliphatic higher alcohol and a higher fatty acid ethylene oxide adduct, a polyalkylene glycol such as polyethylene glycol, block copolymer of polyethylene glycol and polypropylene glycol, and a silicone oil such as dimethylsiloxane, polyether-modified silicone oil and higher alcohol-modified silicone (JP-A's 7-118922 and 7-126970). However, problems with those prior art agents are that they cannot impart any sufficient lubricity, cohesion or the like to biodegradable synthetic yarns fabricated from lactic acid polymers, and so fuzzing and yarn breakage are often found at every step from spinning to down-stream step, especially at a false twisting step. These factors, combined with poor bulkiness, then interact one another, resulting in a failure in producing yarns having satisfactory mechanical properties in a stable fashion.
[0004] An object of the present invention is to provide an agent and method for treating biodegradable synthetic yarns fabricated from a polymer comprising lactic acid as a main component (hereinafter called the lactic acid polymer), which enable improved lubricity, cohesion, etc. to be so imparted to the biodegradable synthetic yarns that the yarns can be prevented from fuzzing and breaking at every step from spinning to down-stream step, especially at a false twisting step and improved in terms of bulkiness, providing yarns having improved mechanical properties in a stable manner.
[0005] The inventors have now found that for treating biodegradable synthetic yarns fabricated from the lactic acid polymer it is reasonably preferable to use an agent comprising a specific functional agent at a given proportion and having a friction coefficient in a predetermined range.
SUMMARY OF THE INVENTION
[0006] Thus, the present invention provides an agent for treating biodegradable synthetic yarns produced from the lactic acid polymer, characterized by comprising 0.1 to 30% by weight of the following functional agent and a lubricant and a surfactant in a total amount of 70 weight % or greater and having the following friction coefficient in the range of 0.04 to 0.35. The present invention also provides a method for treating biodegradable synthetic yarns produced from the lactic acid polymer, characterized in that such an agent for treating biodegradable synthetic yarns is provided in an aqueous solution form, and the yarns are then applied with that aqueous solution in an amount of 0.1 to 3 weight % as calculated on the basis of said agent.
[0007] The functional agent comprises one or more compounds selected from the following polyether compound having an average molecular weight of 3,000 to 20,000, the following polyether polyester compound having an average molecular weight of 3,000 to 50,000 and a polyolefin wax having an average molecular weight of 1,000 to 10,000, wherein:
[0008] said polyether compound is represented by formula 1
[0000] (A−B) n T (formula 1)
[0000] where A is a hydrogen atom, a monovalent hydrocarbon group or an acyl group, B is residual group obtained by removing hydrogen atoms in all hydroxyl groups from polyoxyalkylene glycol containing a polyoxyalkylene group of which the oxyalkylene unit have 2 to 4 carbon atoms, T is a monovalent to tetravalent hydrocarbon group or a hydrogen atom, and n is an integer of 1 to 4 when T is a monovalent to tetravalent hydrocarbon group and 1 when T is a hydrogen atom, and
[0009] said polyether polyester compound comprises one or more compounds selected from a polyether polyester compound obtained by the polycondensation of the following component D and the following component E and a polyether polyester compounds obtained by the polycondensation of the following component D, the following component E and the following component F, wherein:
[0010] said component D comprises one or more compounds selected from an aliphatic dicarboxylic acid having 4 to 22 carbon atoms, an ester-forming derivative of said aliphatic dicarboxylic acid, an aromatic dicarboxylic acid and an ester-forming derivative of said aromatic dicarboxylic acid,
[0011] said component E comprises one or more compounds selected from a polyoxyalkylene monol, a polyoxyalkylene diol and a polyoxyalkylene triol, each containing a polyoxyalkylene group having as a constitutional unit an oxyalkylene unit having 2 to 4 carbon atoms, and
[0012] said component F comprises an alkylene diol having 2 to 6 carbon atoms.
[0013] The friction coefficient of the agent is defined by a value as found in a 25° C. atmosphere having a relative humidity of 65% under a counter weight condition of 40 g/80 g, using a pendulum type oiliness friction tester.
ADVANTAGES OF THE INVENTION
[0014] As can already by understood from the foregoing and the specification and claims which follow, the advantages of the present invention are that improved lubricity, cohesion, etc. are so imparted to the biodegradable synthetic yarns fabricated from the lactic acid polymer that the yarns can be prevented from fuzzing and breaking at every step from spinning to down-stream step, especially at a false twisting step and improved in terms of bulkiness, providing yarns having improved mechanical properties in a stable matter.
[0015] It is therefore an object of the invention is to provide an agent and method for treating biodegradable synthetic yarns fabricated from a polymer comprising lactic acid as a main component.
[0016] It is an additional object of the invention to provide such an agent and method which enable improved lubricity, cohesion, etc. to be so imparted to the biodegradable synthetic yarns and that the yarns can be prevented from fuzzing and breaking at every step from spinning to down-stream step, especially at a false twisting step.
[0017] It is a further object of this invention to provide improved yarns so treated in terms of bulkiness, providing yarns having improved mechanical properties in a stable manner.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] The accompanying drawings, which are incorporated in and form a part of this specification, illustrate embodiments of the invention, and together with the description serve to explain the principles of this invention.
[0019] FIG. 1 depicts Table 1. showing the compositions, etc. of the agents for treating biodegradable synthetic yarns according to the specification.
[0020] FIG. 2 depicts Table 2 which shows the results of various testing of the embodiments of the device and method herein disclosed.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0021] The functional agent used with the agent for treating biodegradable synthetic yarns according to the present invention comprises (1) a polyether compound having an average molecular weight of 3,000 to 20,000 and represented by formula 1, (2) a polyether polyester compound having an average molecular weight of 3,000 to 50,000, which is obtained by the polycondensation of the components D and E, (3) a polyether polyester compound having an average molecular weight of 3,000 to 50,000, which is obtained by the polycondensation of the components D, E and F, and (4) a polyolefin wax having an average molecular weight of 1,000 to 10,000.
[0022] The polyether compound used as the functional agent and represented by formula 1 includes (1) a polyether compound wherein all A's in formula 1 are hydrogen atoms (hereinafter called the polyether compound (a)), (2) a polyether compound wherein some of A's in formula 1 are hydrogen atoms with the rest being monovalent hydrocarbon groups (hereinafter called the polyether compound (b)), (3) a polyether compound wherein all A's in formula 1 are monovalent hydrocarbon groups (hereinafter called the polyether compound (c)), (4) a polyether compound wherein some of A's in formula 1 are hydrogen atom with the rest being acyl groups (hereinafter called the polyether compound (d)), (5) a polyether compound wherein all A's in formula 1 are acyl groups (hereinafter called the polyether compound (e)), (6) a polyether compound wherein some of A's in formula 1 are hydrogen atoms with the rest being monovalent hydrocarbon and acyl groups (hereinafter called the polyether compound (f)), and (7) a polyether compound wherein some of A's in formula 1 are monovalent hydrocarbon groups with the rest being acyl groups (hereinafter called the polyether compound (g)).
[0023] The polyether compounds (a) through (g) may all be synthesized by methods known in the art. For instance, the polyether compound (a) may be synthesized by the successive addition of an alkylene oxide having 2 to 4 carbon atoms to the monovalent to tetravalent hydroxy compound having a hydrocarbon group, which corresponds to T in formula 1. The polyether compounds (b) and (c) may each be synthesized by hindering the whole or a part of terminal hydroxyl groups in the polyether compound (a) with the hydrocarbon groups corresponding to A in formula 1 by means of etherification. The polyether compounds (d) and (e) may each be synthesized by hindering the whole or a part of terminal hydroxyl groups in the polyether compound (a) with the acyl groups corresponding to A in formula 1 by means of acylation. The polyether compounds (f) and (g) may each be synthesized by hindering the whole or a part of terminal hydroxyl groups in the polyether compound (a) with the hydrocarbon groups corresponding to A in formula 1 by means of etherification and with the acyl groups corresponding to A in formula 1 by means of acylation.
[0024] The monovalent to tetravalent hydroxy compounds used for the synthesis of polyether compound (a) include (1) monovalent, aliphatic hydroxy compounds having 1 to 40 carbon atoms such as methyl alcohol, butyl alcohol, octyl alcohol, lauryl alcohol, stearyl alcohol, ceryl alcohol, isobutyl alcohol, 2-ethylhexyl alcohol, isododecyl alcohol, isohexadecyl alcohol, isostearyl alcohol, isotetracosanyl alcohol, 2-propanol, 2-hexanol, 12-eicosanol, vinyl alcohol, butenyl alcohol, hexadecenyl alcohol, oleyl alcohol, eicosenyl alcohol, 2-methyl-2-propylene-1-ol,6-ethyl-2-undecen-1-ol, 2-octen-5-ol and 15-hexadecen-2-ol; (2) monovalent hydroxy compounds having an aromatic ring such as phenol, propylphenol, octylphenol and tridecylphenol ; and (3) divalent to tetravalent, aliphatic hydroxy compounds such as ethylene glycol, propylene glycol, butanediol, hexanediol, neopentyl glycol, glycerin, trimethylolpropane and pentaerythritol. Among these, monovalent, aliphatic hydroxy compounds having 1 to 6 carbon atoms and divalent, aliphatic hydroxy compounds having 2 to 4 carbon atoms are preferred, although particular preference is given to propyl alcohol, butyl alcohol, ethylene glycol, propylene glycol and trimethylolpropane.
[0025] The alkylene oxides having 2 to 4 carbon atoms used for the synthesis of polyether compound (a), for instance, include ethylene oxide, propylene oxide, 1,2-butylene oxide and 1,4-butylene oxide, which may be used alone or in admixture. When the alkylene oxides are used in admixture, they may be added to the hydroxy compound in random addition, block addition, and block·random addition forms.
[0026] In the polyether compounds (b) and (c), the monovalent hydrocarbon group corresponding to A in formula 1, for instance, includes (1) monovalent, aliphatic hydrocarbon groups having 1 to 8 carbon atoms such as methyl, ethyl, propyl, butyl, octyl, vinyl, butenyl and hexadecenyl groups and (2) monovalent hydrocarbon groups having an aromatic ring such as phenoxy, propylphenoxy, octylphenoxy and benzyl groups; however, preference is given to methyl groups. Known processes may be applied to the synthesis of such polyether compounds (b) and (c). For instance, use may be made of a process wherein an alkyl halide reacts with a metal complex salt of the polyether compound (a).
[0027] In the polyether compounds (d) and (e), the acyl group corresponding to A in formula 1, for instance, includes (1) aliphatic acyl groups having 2 to 22 carbon atoms such as acetyl, propanoyl, butanoyl, hexnoyl, heptanoyl, oxtanoyl, nonanoyl, decanoyl, hexadecanoyl, octadecanoyl, hexadecenoyl, eicosenoyl and octadecenoyl groups and (2) acyl groups having an aromatic ring such as benzoyl, toluoyl and naphthoyl groups, among which decanoyl and octadecenoyl groups are preferred. Known processes may be applied to the synthesis of such polyether compounds (d) and (e). For instance, use may be made of a process wherein an acyl halide reacts with a metal complex salt of the polyether compound (a).
[0028] For the hydrocarbon group corresponding to A in formula 1 in the polyether compounds (f) and (g), the same as referred to in conjunction with the polyether compounds (b) and (c) may hold true, and for the acyl group corresponding to A in formula 1, the same as referred to in conjunction with the polyether compounds (d) and (e) may go true. Known processes may be applied to the synthesis of such poylyether compounds (f) and (g). For instance, use may be made of processes wherein an alkyl halide reacts with a metal complex salt of the polyether compound (a) and an acyl halide reacts with the resulting reaction product.
[0029] All the polyether compounds as mentioned above and represented by formula 1 have an average molecular weight of 3,000 to 20,000, and preferably 3,500 to 18,000.
[0030] The polyether polyester compound used as the functional agent includes (1) a polyether polyester compound obtained by the polycondensation of component (D) and component (E), and (2) a polyether polyester compound obtained by the polycondensation of component (D), component (F) and component (F).
[0031] The component (D) used for the synthesis of the polyether polyester compound, for instance, includes (1) aliphatic dicarboxylic acids having 4 to 22 carbon atoms such as succinic acid, adipic acid, azelaic acid, sebacic acid, α,ω-dodecane dicarboxylic acid, dodecenylsuccinic acid, octadecenyl dicarboxylic acid and cyclohexane dicarboxylic acid, (2) aromatic dicarboxylic acids such as phthalic acid, isophthalic acid, terephthalic acid, 5-sulfoisophthalic acid, 2,6-naphthalene dicarboxylic acid, 2,3-naphthalene dicarboxylic acid and 1,4-naphthalene dicarboxylic acid, (3) ester-forming derivatives of said (1) such as dimethyl succinate, dimethyl adipate, dimethyl azelate and dimethyl sebacate, and (4) ester-forming derivatives of said (2) such as dimethyl phthalate, dimethyl isophthalate, dimethyl terephthalate, 5-sulfoisophthalic acid dimethyl ester salt, 2,6-bis(methoxycarbonyl)-naphtalene,2,6-bis(ethoxycarbonyl)-naphthalene and 1,4-bis(methoxycarbonyl)-naphthalene. Among these, preference is given to the aliphatic dicarboxylic acids having 6 to 12 carbon atoms, e.g., adipic acid, azelaic acid and sebacic acid, the aromatic dicarboxylic acid, e.g., phthalic acid, terephthalic acid and 5-sulfoisophthalic acid dimethyl ester salt, and the ester-forming derivatives thereof. Such organic dicarboxylic acids and ester-forming derivaties thereof, when used for polycondensation, may be used alone or in combination of two or more.
[0032] The component (E) used for polyether polyester synthesis contains polyoxyalkylene monols, polyoxyalkylene diols and polyoxyalkylene trials or any desired mixtures thereof, wherein an oxyalkylene unit having 2 to 4 carbon atoms is used as the constitutional unit.
[0033] The polyoxyalkylene monols, for instance, include those wherein one terminals of such polyoxyalkylene diols as mentioned below are hindered by monovalent hydrocarbon groups. Such monovalent hydrocarbon groups, for instance, include (1) aliphatic hydrocarbon groups having 1 to 22 carbon atoms, e.g., methyl, ethyl, butyl, n-octyl, lauryl, stearyl, isopropyl and 2-ethylhexyl groups and (2) hydrocarbon groups having an aromatic ring, e.g., phenyl, monobutylphenyl, octylphenyl and nonylphenyl groups, among which the phenyl group is preferred.
[0034] The polyoxyalkylene diols, for instance, include reaction products obtained by the addition of an alkylene oxide having 2 to 4 carbon atoms to alkylene diols having 2 to 6 carbon atoms, e.g., ethylene glycol, 1,2-propane-diol, 1,3-propanediol, 1,4-butanediol, 1,6-hexanediol and neopentyl glycol. Preference is given to polyoxyalkylene diols having an average molecular weight of 500 to 5,000, and particular preference is given to polyoxyalkylene dials having such an average molecular weight, wherein the oxyalkylene unit comprises an oxyethylene unit or an oxyethylene unit and an oxypropylene unit and the oxyethylene unit/oxypropylene unit proportion is in the range of 100/0 to 50/50 (mold %).
[0035] The polyoxylalkylene triols include reaction products obtained by the addition of an alkylene oxide having 2 to 4 carbon atoms to an alkylene dial having 2 to 6 carbon atoms, e.g., glycerol and trimethylolpropane. Preference is given to polyoxyalkylene triols having an average molecular weight of 500 to 5,000, and particular preference is given to polyoxyalkylene dials having such an average molecular weight, wherein the oxyalkylene unit comprises an oxyethylene unit or an oxyethylene unit and an oxypropylene unit and the oxyethylene unit/oxypropylene unit proportion is in the range of 100/0 to 50/50 (mol %).
[0036] The component (F) used for polyether polyester synthesis includes an alkylene diol having 2 to 6 carbon atoms, e.g., ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,4-butanediol, 1,6-hexanediol and neopenthyl glycol, among which ethylene glycol, 1,2-propanediol and 1,3-propanediol are preferred.
[0037] When the polyether polyester compound used as the functional agent is a reaction product obtained by the polycondensation of component (D) and component (E), it should preferably contain a constitutional unit formed from component (D) at a proportion of 40 to 60 mol %, preferably 48 to 52 mol %, and a constitutional unit formed from component (E) at a proportion of 40 to 60 mol %, preferably 48 to 52 mol %. When that polyether polyester compound is a reaction product obtained by the polycondensation of component (D), component (E) and component (F), it should preferably contain a constitutional unit formed from component (D) at a proportion of 20 to 40 mol %, preferably 20 to 25 mol %, a constitutional unit formed from component (E) at a proportion of 5 to 30 mol %, preferably 15 to 20 mol %, and a constitutional unit formed from component (F) at a proportion of 40 to 70 mol %, preferably 50 to 60 mol %.
[0038] Known processes may be applied to the synthesis of the polyether polyester compound used as the functional agent. For instance, reliance is on a direct poly-condensation process wherein an organic dicarboxylic acid that is component (D), a polyoxylalkylene diol that is component (E) and an alkylene diol that is component (F) are subjected to polycondensation in the presence of an anionic polymerization catalyst, a cationic polymerization catalyst, a coordination anionic polymerization catalyst or the like known in the art and under high-temperature, high-vacuum conditions while low-molecular-weight compounds are distilled off, thereby obtaining a polyether polyester compound.
[0039] Referring to the polyether polyester compounds as explained above, both the polyether polyester compound obtained from component (D) and component (E) and the polyether polyester compound obtained from component (D), component (E) and component (F) should have an average molecular weight of 3,000 to 50,000, and preferably 3,500 to 40,000.
[0040] The polyolefin wax used as the functional agent, for instance, includes oxidized polyethylene wax and copolymers of α-olefin and unsaturated fatty acids. The α-olefin used for the synthesis of such copolymers, for instance, includes ethylene, 1 propylene, 1 butene, 1 decene, 1 dodecene and 1 octadodecene. The unsaturated fatty acids, for instance, include acrylic acid, methacrylic acid, 4-pentenoic acid and 5-hexenoic acid. Preferable polyolefin waxes are oxidized polyethylene wax, and copolymers of ethylene and/or 1 propylene and acrylic acid and/or methacrylic acid. The waxes used should all have an average molecular weight of 1,000 to 10,000.
[0041] In the agent for treating biodegradable synthetic yarns according to the present invention, one or two or more compounds selected from such polyether compounds, polyether polyester compounds and polyolefin waxes as explained above is or are used as the functional agent or agents. However, it is preferable to use one or two or more compounds selected from the polyether compounds having an average molecular weight of 3,500 to 18,000 and the polyether polyester compounds having an average molecular weight of 3,500 to 40,000.
[0042] The agent for treating biodegradable synthetic yarns according to the present invention contains, in addition to the functional agent as explained above, a lubricant and a surfactant. For such a lubricant, lubricants that are known per se, for instance, aliphatic esters, polyether compounds and mineral oils or any desired mixtures thereof may be used.
[0043] The aliphatic ester used as the lubricant is obtained by the esterification of an aliphatic alcohol and a fatty acid, wherein carbon atoms of a hydrocarbon group in the aliphatic alcohol moiety and carbon atoms of a hydrocarbon group in the fatty acid moiety preferably adds up to 17 to 60, and more preferably 22 to 36. The aliphatic alcohols used for the synthesis of such aliphatic esters, for instance, include (1) aliphatic monohydric alcohols such as methyl alcohol, ethyl alcohol, butyl alcohol, 2-ethylhexyl alcohol, lauryl alcohol, palmityl alcohol, palmitoleyl alcohol, stearyl alcohol, isostearyl alcohol, oleyl alcohol and behenyl alcohol and (2) aliphatic polyhydric alcohols such as ethylene glycol, propylene glycol, butanediol, hexanediol, glycerol, trimethylolpropane, sorbitol and pentaerythritol. The fatty acids, for instance, include (1) saturated aliphatic monocarboxylic acids such as acetic acid, butyric acid, caproic acid, caprylic acid, capric acid, undecanoic acid, lauric acid, tridecanoic acid, myristic acid, pentadecanoic acid, palmitic acid, stearic acid, nonadecanoic acid, arachic acid, behenic acid, cerotic acid, montanic acid and mellisic acid, (2) aliphatic monoenoic monocarboxylic acids such as linderic acid, palmitoleic acid, oleic acid, elaidic acid and vaccenic acid, (3) aliphatic nonconjugated polyenoic monocarboxylic acids such as linolic acid, linoleic acid and arachidonic acid, and (4) aliphatic dicarboxylic acids such as succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid and sebacic acid. More specifically, fatty acid esters obtained from aliphatic monohydric alcohols and aliphatic monocarboxylic acids, for instance, include lauryl oleate, stearyl oleate, oleyl oleate, octyl oleate, tridecyl oleate, methyl oleate, butyl oleate, 2-ethylhexyl oleate, octyl stearate, oleyl stearate, oleyl palmitate, oleyl laurate, oleyl isostearate and oleyl octanate, with lauryl oleate and octyl stearate being preferred. Exemplary fatty acid esters obtained from aliphatic polyhydric alcohols and aliphatic monocarboxylic acids are ethylene glycol dilaurate, propylene glycol distearate, butanediol palmitate, hexanediol dilaurate, glycerol tri(12-hydroxystearate), glycerol trioleate, glycerol palmitate distearate, trimethylolpropane tripalmitate, sorbitan tetraoleate and pentaerythritol tetralaurate, with glycerol tri(12-hydroxystearate) and soribtan tetraoleate being preferred. Exemplary fatty acid esters obtained from aliphatic monohydric alcohols and aliphatic dicarboxylic acids are distearyl succinate, distearyl glutarate, dicetyl adipate, dibehenyl pimelate, dibehenyl suberate, disteary azelate and distearyl sebacate, with dicetyl adipate being preferred.
[0044] Preferable for the polyether compound used as the lubricant are those represented by the aforesaid formula 1 and having an average molecular weight in the range of 700 to 2,900.
[0045] The mineral oil used as the lubricant should have a viscosity at 30° C. of preferably 2×10 −6 to 2×10 −4 m 2 /s, and more preferably 2×10 −6 to 2×10 −5 m 2 /s. The more preferable mineral oil is a liquid paraffin oil.
[0046] The surfactant used may be those that are known per se, e.g., nonionic surfactants, anionic surfactants, cationic surfactants and amphoteric surfactants or any desired mixtures thereof.
[0047] The nonionic surfactants used, for instance, include (1) oxyalkylene adducts of aliphatic monohydric alcohols having 6 to 22 carbon atoms, (2) fatty acid esters of oxyalkylene adducts of aliphatic monohydric alcohols having 6 to 22 carbon atoms, (3) fatty acid esters of aliphatic polyhdric alcohols having 2 to 6 carbon atoms, (4) fatty acid esters of oxyalkylene adducts of aliphatic polyhydric alcohols having 2 to 6 carbon atoms, (5) oxyalkylene adducts of aliphatic amines having 6 to 22 carbon atoms, and (6) oxyalkylene adducts of aliphatic amides having 6 to 22 carbon atoms.
[0048] Referring to the oxyalkylene adducts of the aliphatic monohydric alcohols having 6 to 22 carbon atoms, used as the nonionic surfactant, the aliphatic monohydric alcohols having 6 to 22 carbon atoms, used as the synthesis material for the same, include hexyl alcohol, octyl alcohol, nonyl alcohol, decyl alcohol, undecyl alcohol, dodecyl alcohol, tridecyl alcohol, tetradecyl alcohol, pentadecyl alcohol, hexadecyl alcohol, hexadecenyl alcohol, heptadecyl alcohol, octadecyl alcohol, octadecenyl alcohol, nonadecyl alcohol, eicosyl alcohol, eicosenyl alcohol, docosayl alcohol, 2-ethylhexyl alcohol, 3,5,5-trimethylhexyl alcohol, etc. Among these, aliphatic monohydric alcohols having 8 to 18 carbon atoms are preferred, although 2-ethylhexyl alcohol and dodecyl alcohol are particularly preferred. Oxyalkylene adducts of such aliphatic monohydric alcohols having 6 to 22 carbon atoms, for instance, include oxyethylene adducts, oxypropylene adducts and oxyethylene-oxypropylene adducts as well as any desired mixtures thereof; however, preference is given to oxyalkylene adducts wherein oxylalkylenes are added at a proportion of 3 to 30 moles per mole of the aliphatic monohydric alcohol having 6 to 22 carbon atoms.
[0049] Referring to the fatty acid esters of oxyalkylene adducts of the aliphatic monohydric alcohols having 6 to 22 carbon atoms, used as the nonionic surfactant, the same as explained previously holds for the oxyalkylene adducts of aliphatic monohydric alcohols having 6 to 22 carbon atoms, used as the synthesis material for one of the same. In this case, however, it is preferable to add the oxyalkylene at a proportion of 1 to 10 moles per mole of the aliphatic monohydric alcohol having 6 to 22 carbon atoms. The fatty acid used as another synthesis material, for instance, includes (1) saturated aliphatic monocarboxylic acids having 2 to 22 carbon atoms such as acetic acid, butyric acid, caproic acid, caprylic acid, capric acid, undecanoic acid, lauric acid, tridecanoic acid, myristic acid, pentadecanoic acid, palmitic acid, stearic acid, nonadecanoic acid, arachic acid, behenic acid, cerotic acid, montanic acid and mellisic acid, (2) aliphatic monoenemonocarboxylic acids such as linderic acid, palmitoleic acid, oleic acid, elaidic acid and vaccenic acid, (3) aliphatic nonconjugated polyenoic acids having 18 to 22 carbon atoms such as linolic acid, linoleic acid and arachidonic acid, and (4) aliphatic dicarboxylic acids such as succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid and sebacic acid.
[0050] Referring to fatty acid esters of aliphatic polyhydric alcohols having 2 to 6 carbon atoms, used as the nonionic surfactant, the aliphatic polyhydric alcohols having 2 to 6 carbon atoms, used as the synthesis material for one of the same, for intance, include ethylene glycol, propylene glycol, butanediol, hexanediol, glycerol, trimethylolpropane, sorbitol and pentaerythritol. The same as explained previously goes true for the fatty acids used as another synthesis material. Exemplary fatty acid partial esters of such polyhydric alcohols are ethylene glycol monolaurate, propylene glycol monostearate, butanediol monopalmitate, hexanediol monolaurate, glycerol di(12-hydroxystearate), glycerol dioleate, glycerol monopalmitate monostearate, trimethylolpropane dipalmitate, sorbitan monooleate and pentaerythritol dilaurate, with glycerol di(12-hydroxystearate) and sorbitan monooleate being preferred.
[0051] Referring to the fatty acid esters of oxyalkylene adducts of the aliphatic polyhydric alcohols having 2 to 6 carbon atoms, used as the nonionic surfactant, the same as set forth previously holds true for the aliphatic polyhydric alcohols having 2 to 6 carbon atoms, used as the synthesis material for one of the same. Such oxyalkylene adducts of the aliphatic polyhydric alcohols having 2 to 6 carbon atoms, for instance, include oxyethylene adducts, oxypropylene adducts and oxyethylene-oxypropylene adducts or any desired mixtures thereof. However, it is preferable to use adducts wherein the oxyalkylene is added at a proportion of 3 to 40 moles per mole of the aliphatic polyhydric alcohol having 2 to 6 carbon atoms. The same as mentioned previously goes true for the fatty acids used as another synthesis material. Examples of such fatty acid esters of oxyalkylene adducts of the aliphatic polyhydric alcohols having 2 to 6 carbon atoms are polyoxyethylene glycol dilaurate, polyoxypropylene glycol distearate, 1,4-di(polyoxyethylene)butanediol palmitate, 1,6-di(polyoxyethylene-polyoxypropylene)hexanediol dilaurate, and 1,2,3-tri(polyoxyethylene)glycerol tri(12-hydroxystearate), although polyoxyethylene glycol dilaurate and 1,2,3-tri(polyoxyethylene)glycerol tri(12-hydroxystearate) are preferred.
[0052] Referring to the oxyalkylene adducts of aliphatic amines having 6 to 22 carbon atoms, used as the nonionic surfactant, the aliphatic amines having 6 to 22 carbon atoms, used as the synthesis material for the same, include (1) saturated aliphatic amines such as hexylamine, octylamine, nonylamine, laurylamine, myristylamine, cetylamine, stearylamine and arachinylamine, (2) unsaturated aliphatic amines scuh as 2-tetradecenylamine, 2-pentadecenylamine, 2-octadecenylamine, 15-hexadecenylamine, oleylamine, linolenylamine and eleostearylamine, and so on, among which laurylamine, palmitylamine and stearylamine are preferred. Such oxyalkylene adducts of the aliphatic amines having 6 to 22 carbon atoms, for instance, include oxyethylene adducts, oxypropylene adducts and oxyethylene-oxypropylene adducts or any desired mixtures thereof. However, it is preferable to use adducts wherein the oxyalkylene is added at a proportion of 2 to 20 moles per mole of the aliphatic amines having 6 to 22 carbon atoms.
[0053] Referring to the oxyalkylene adducts of aliphatic amide compounds having 6 to 22 carbon atoms, used as nonionic surfactant, the aliphatic amide compounds having 6 to 22 carbon atoms, used as the synthesis material for the same, includes those obtained by the amidation of polyalkylene polyamines and fatty acids. In such amidation, the proportion of fatty acids to the polyalkylene polyamines should be such that at least one of terminal amino groups of polyalkylene polyamine has to be amidated; however, that proportion should preferably be such that amino groups at both terminals of polyalkylene polyamine be amidated. The polyalkylene polyamines that form such fatty acid amides, for instance, include diethylenetriamine, triethylenetetramine, di(trimethylene)triamine and tri(trimethylene)tetramine, among which diethylenetriamine is preferred. The fatty acids used, for instance, include caproic acid, caprylic acid, capric acid, undecanoic acid, lauric acid, tridecanoic acid, myristic acid, pentadecanoic acid, palmitic acid, stearic acid, nonadecanoic acid, arachidic acid, behenic acid, cerotic acid, montanic acid, mellisic acid, linderic acid, palmitoleic acid, oleic acid, elaidic acid and vaccenic acid, among which laruic acid and oleic acid are preferred. Such oxyalkylene adducts of the aliphatic amide compounds having 6 to 22 carbon atoms, for instance, include oxyethylene adducts, oxypropylene adducts and oxyethylene-oxypropylene adducts or any desired mixtures thereof. However, it is preferable to use adducts wherein the oxyalkylene is added at a proportion of 1 to 15 moles per mole of the aliphatic amide compound having 6 to 22 carbon atoms.
[0054] The anionic surfactant used herein, for instance, include fatty acid salts, organic sulfonic acid salts, organic sulfuric acid salts and organic phosphoric acid ester salts. The fatty acid salts used as the anionic surfactant include (1) alkaline metal salts of fatty acids having 6 to 22 carbon atoms, and (2) amine salts of fatty acids having 6 to 22 carbon atoms. Such fatty acids having 6 to 22 carbon atoms, for instance, include capric acid, caprylic acid, lauric acid, myristic acid, palmitic acid, stearic acid, behenic acid, oleic acid, erucic acid, linolic acid and dodecenylsuccinic acid. The alkaline metals that form such alkaline metal salts of fatty acids having 6 to 22 carbon atoms, for instance, are sodium, potassium and lithium, and the amines that form the amine salts, for instance, are (1) aliphatic amines such as methylamine, dimethylamine, trimethylamine, ethylamine, diethylamine, triethylamine, butylamine, dibutylamine, tributylamine and octylamines, (2) aromatic or heterocyclic amines such as aniline, pyridine, morphorine and piperazine or derivatives thereof, (3) alkanolamines such as monoethanolamine, diethanolamine, triethanolamine, isopropanolamine, diisopropanolamine, triisopropanolamine, butyldiethanolamine, octyldiethanolamine and lauryldiethanolamine, and (4) ammonia. Among these, potassium dodecenylsuccinate is preferred.
[0055] The organic sulfonic acid salts used as the anionic surfactant used herein, for instance, include (1) alkaline metal alkylsulfonates such as sodium decylsulfonate, sodium dodecylsuflonate, lithium tetradecylsulfonate and potassium hexadecylsulfonate, (2) alkaline metal alkylarylsulfonates such as sodium butylbenzenesulfonate, sodium dodecylbenzenesulfonate, potassium octadecyl-benzenesulfonate and sodium dibutylnaphthalenesulonate, and (3) alkaline metal ester sulfonates such as sodium 1,2-bis(dioctyloxycarbonyl)-ethanesulfonate, lithium 1,2-bis(dibutyloxycarbonyl)-ethanesulfonate, sodium 2-(dodecyloxy)-2-oxoethane-1-sulfonate and potassium 2-(nonylphenoxy)-2-oxoethane-1-sulfonate. Among these, alkaline metal alkylsulfonates and alkaline metal alkylarylsufonates, especially with 12 to 18 carbon atoms, are preferred.
[0056] The organic sulfates used as the anionic surfactant, for instance, include (1) alkaline metal alkylsuflates such as sodium decylsulfate, sodium dodecylsulfate, lithium tetradecylsulfate and potassium hexadecylsulfate, and (2) alkaline metal salts of sulfides of natural fats and oils such as sulfated tallow oil and sulfated castor oil. In particular, sodium dodecylsulfate is preferred.
[0057] The organic phosphoric acid ester salts used as the anionic surfactant include (1) alkyl phosphoric ester salts containing an alkyl group having 4 to 22 carbon atoms, and (2) (poly)oxyalkylene alkyl ether phosphoric ester salts in which an alkyl group has 4 to 22 carbon atoms and the number of an oxyalkylene unit that forms a (poly)oxy-alkylene group is 1 to 5.
[0058] The alkyl phosphoric ester salts containing an alkyl group having 4 to 22 carbon atoms, for instance, include butyl phosphoric ester salt, pentyl phosphoric ester salt, hexyl phosphoric ester salt, octyl phosphoric ester salt, isooctyl phosphoric ester salt, 2-ethylhexyl phosphoric ester salt, decyl phosphoric ester alkali metal salt, lauryl phosphoric ester alkali metal salt, tridecyl phosphoric ester salt, myristyl phosphoric ester salt, cetyl phosphoric ester salt, stearyl phosphoric ester salt, eicosyl phosphoric ester salt and behenyl phosphoric ester salt. These alkyl phosphoric ester salts also include a pure form of monoester and a pure form of diester or mixtures thereof. The diester includes a diester having identical alkyl groups (symmetric diester) and a diester having different alkyl groups (asymmetric diester). The alkyl phosophoric ester salt as explained above is formed from an acidic alkyl phosphoric ester, and a base compound for which an alkali metal hydroxide, an organic amine compound, an ammonium compound or the like are mentioned.
[0059] The (poly)oxyalkylene alkyl phosphoric ester salt, in which the alkyl group has 4 to 22 carbon atoms and the number of an oxyalkylene unit that forms a (poly)oxyalkylene group, includes polyoxyalkylene butyl ether phosphoric ester salt, polyoxylalkylene hexyl ether phosphoric ester salt, polyoxylalkylene octyl ether phosphoric ester salt, polyoxyalkylene isooctyl ether phosphoric ester salt, polyoxyalkylene decyl ether phosphoric ester salt, polyoxyalkylene lauryl ether phosphoric ester salt, polyoxyalkylene tridecyl ether phosphoric ester alkali metal salt, polyoxyalkylene myristyl ether phosphoric ester alkali metal salt, polyoxyalkylene cetyl ether phosphoric ester salt, polyoxyalkylene stearyl ether phosphoric ester salt, polyoxyalkylene behenyl ether phosphoric ester salt, etc. The (poly)oxyalkylene group in such (poly)oxyalkylene alkyl ether phosphoric ester salts, for instance, includes (poly)oxyethylene group, (poly)oxypropylene group and (poly)oxyethylene-oxypropylene group. These polyoxyalkylene alkyl ether phosphoric ester salts also include a pure form of monoester and a pure form of diester or mixtures thereof. The diester includes a diester having identical alkyl groups (symmetric diester) and a diester having different alkyl groups (asymmetric diester). The (poly)oxyalkylene alkyl ether phosphoric ester salt as explained above is formed from an acidic (poly)oxyalkylene alkyl ether phosphoric ester, and a base compound for which an alkali metal hydroxide, an organic amine compound, an ammonium compound or the like are mentioned.
[0060] The cationic surfactant used includes a quaternary ammonium salt and an organic amine oxide. The quaternary ammonium salts used as the cationic surfactant, for instance, includes tetramethylammonium salt, triethylmethylammonium salt, tripropylethylammonium salt, tributylmethylammonium salt, tetrabutylammonium salt, triisooctylethylammonium salt, trimethyloctylammonium salt, dilauryldimethylammonium salt, trimethylstearylammonium salt, dibutenyldiethylammonium salt, dimethyldioleyl-ammonium salt, trimethyloleylammonium salt, tributylhydroxyethylammonium salt, dipropyl bis(2-hydroxyethyl)ammonium salt, octyl tris(2-hydroxyethyl)ammonium salt, and methyl tris(3-hydroxpropyl)ammonium salt.
[0061] The organic amine oxide used as the cationic surfactant, for instance, includes hexylamine oxide, octylamine oxide, nonylamine oxide, laurylamine oxide, myristylamine oxide, cetylamine oxide, stearylamine oxide, arachinylamine oxide, dihexylamine oxide, dioctylamine oxide, dinonylamine oxide, dilaurylamine oxide, dimyristylamine oxide, dicetylamine oxide and distearylamine oxide.
[0062] Various amphoteric surfactants may be used; however, it is preferable to use betaine type amphoretic surfactants such as octyl dimethyl ammonioacetate, decyl dimethyl ammonioacetate, dodecyl dimethyl ammonioacetate, hexadecyl dimethyl ammonioacetate, octadecyl dimethyl ammonioacetate, nonadecyl dimethyl ammonioacetate and octadecenyl dimethyl ammonioacetate.
[0063] As the surfactant used with the agent for treating biodegradable synthetic yarns according to the present invention, the nonionic, anionic, cationic and amphoteric surfactants may be used alone or in admixture of two or more; however, it is preferable to use the nonionic and anionic surfactants in admixture. More preferably in this case, a fatty acid salt and/or an organic sulfonic acid salt is used as the anionic surfactant.
[0064] The agent for treating biodegradable synthetic yarns according to the present invention comprises a functional agent in an amount of 0.1 to 30 weight %, preferably 0.5 to 20 weight %, and a lubricant and a surfactant in a total amount of 70 weight % or greater, preferably 80 weight % or greater. In one preferable embodiment of the invention, the agent comprises 20 to 80 weight % of lubricant and 10 to 70 weight % of surfactant, and in one more specific embodiment, that agent should more preferably comprise 1 to 18 weight % of functional agent, 34 to 75 weight % of lubricant and 15 to 65 weight % of surfactant.
[0065] Besides the functional agent, lubricant and surfactant as explained above, the agent for treating biodegradable synthetic yarns according to the present invention may contain other components such as antioxidants, antiseptic agent and rust preventives with the proviso that their contents are reduced as much as possible.
[0066] The agent for treating biodegradable synthetic yarns according to the present invention should have a friction coefficient in the range of 0.04 to 0.35, and preferably 0.05 to 0.16. The “friction coefficient” used herein is understood to be indicative of a value as measured in an atmosphere of 25° C. and a relative humidity of 65% under a counter weight condition of 40 g/80 g, using a pendulum type oiliness friction tester.
[0067] Referring to how to treat biodegradable synthetic yarns according to the present invention, the aforesaid agent for treating biodegradable synthetic yarns according to the present invention is first prepared in an aqueous solution form. Then, biodegradable synthetic yarns fabricated from the lactic acid polymer are oiled with that aqueous solution in an amount of 0.1 to 3% by weight, and preferably 0. 5 to 1.5% by weight as calculated on the basis of said agent for treating biodegradable synthetic yarns. Known oiling methods such as a roller oiling method, a guide oiling method using a measuring pump, a dip oiling method and a spray oiling method may be used. Oiling may be carried out at the step of spinning biodegradable synthetic yarns fabricated from the lactic acid polymer or at the step of carrying out spinning and drawing simultaneously. It is here noted that the present invention can most efficiently be applied to biodegradable synthetic yarns that are subjected to false twisting.
[0068] The agent and method for the treatment of biodegradable synthetic yarns according to the present invention may be applied to biodegradable synthetic yarns that are fabricated from (1) polylactic acid that is a homopolymer of lactic acid, (2) a lactic acid copolymer obtained from lactic acid and a cyclic lactone such as ε-caprolactone, γ-butyrolactone and γ-valerolactone , (3) a lactic acid copolymer obtained from lactic acid and a hydroxy acid such as hydroxybutyric acid, hydroxy-isobutyric acid and hydroxyvaleric acid, (4) a lactic acid copolymer obtained from lactic acid and a glycol such as ethylene glycol, propylene glycol and 1,4-butanediol, (5) lactic acid and a dicarboxylic acid such as succinic acid, sebacic acid and adipic acid, and (6) mixtures of two or more of (1) to (5) above.
PREFERRED EMBODIMENTS OF THE INVENTION
[0069] Set out below are nine embodiments (1) to (9) of the agent for treating biodegradable synthetic yarns according to the present invention.
First Embodiment
[0070] An agent for treating biodegradable synthetic yarns fabricated from the lactic acid polymer, which comprises 10 weight % of the following functional agent (K-1), 75 weight % of the following lubricant (L-1) and 15 weight % of the following surfactant (S-1), and has a friction coefficient of 0.09:
Functional Agent (K-1)
[0071] A polyether compound having an average molecular weight of 10,000, which is obtained by the random addition of ethylene oxide and propylene oxide to ethylene glycol at an ethylene oxide-to-propylene oxide proportion of 50/50 by mole.
Lubricant (L-1)
[0072] A 1/1 by-weight mixture of a polyether monol having an average molecular weight of 1,100, which is obtained by the random addition of ethylene oxide and propylene oxide to butyl alochol at an ethylene oxide-to-propylene oxide proportion of 60/40 by mole and a polyether monol having a number-average molecular weight of 2,400, which is obtained by the random addition of ethylene oxide and propylene oxide to butyl alcohol at an ethylene oxide-to-propylene oxide proportion of 75/25 by mole.
Surfactant (S-1)
[0073] A 67/27/6 by-weight mixture of polyoxyethylene (with the number of repetition of oxyethylene unit being 5, hereinafter mentioned n=5) lauryl ether/sorbitan monooleate/sodium dodecylsulfonate.
Second Embodiment
[0074] An agent for treating biodegradable synthetic yarns fabricated from the lactic acid polymer, which comprises 16 weight % of the following functional agent (K-2), 62 weight % of the following lubricant (L-2), 21 weight % of the aforesaid surfactant (S-1) and 1 weight % of the following subordinate component (E-1), and has a friction coefficient of 0.07.
Functional Agent (K-2)
[0075] A polyether compound having an average molecular weight of 6,000, which is obtained by the random addition of ethylene oxide and propylene oxide to trimethylolpropane at an ethylene oxide-to-propylene oxide proportion of 70/30 by mole and in which hydrogen atoms in all hydroxyl groups of resulting polyether triol are substituted by methyl groups.
Lubricant (L-2)
[0076] A 1/2 by-weight mixture of polyether monol having an average molecular weight of 2, 500, which is obtained by the random addition of ethylene oxide and propylene oxide to dodecyl alcohol at an ethylene oxide-to-propylene oxide proportion of 40/60 by mole and polyether diol having a number-average molecular weight of 1,000, which is obtained by the random addition of ethylene oxide and propylene oxide to ethylene glycol at an ethylene oxide-to-propylene oxide proportion of 80/20 by mole.
Subordinate Component (E-1)
[0077] A polyether-modified silicone.
Third Embodiment
[0078] An agent for treating biodegradable synthetic yarns fabricated from the lactic acid polymer, which comprises 11 weight % of the following functional agent (K-3), 74 weight % of the aforesaid lubricant (L-1) and 15 weight % of the aforesaid surfactant (S-1), and has a friction coefficient of 0.10.
Functional Agent (K-3)
[0079] A polyether compound having an average molecular weight of 3,500, which is obtained by the random addition of ethylene oxide and butylene oxide to ethylene glycol at an ethylene oxide-to-butylene oxide proportion of 70/30 by mole and in which hydrogen atoms in all hydroxyl groups of resulting polyether diol are substituted by decanoyl groups.
Fourth Embodiment
[0080] An agent for treating biodegradable synthetic yarns fabricated from the lactic acid polymer, which comprises 5 weight % of the aforesaid functional agent (K-3), 40 weight % of the aforesaid lubricant (L-1) and 55 weight % of the following surfactant (S-2), and has a friction coefficient of 0.11.
Surfactant (S-2)
[0081] A 14/85/2 by-weight mixture of polyoxyethylene (n=5) lauryl ether/decanoic ester of polyoxyethylene (n=4) lauryl ester/dipotassium dodecenylsuccinate.
Fifth Embodiment
[0082] An agent for treating biodegradable synthetic yarns fabricated from the lactic acid polymer, which comprises 1 weight % of the following functional agent (K-6), 42 weight % of the aforesaid lubricant (L-1) and 57 weight % of the aforesaid surfactant (S-2), and has a friction coefficient of 0.08.
Functional Agent (K-6)
[0083] A polyether polyester compound having an average molecular weight of 20,000, which is obtained from a 1/1 by-mole mixture of dimethyl terephthalate and polyethylene glycol having an average molecular weight of 1,000.
Sixth Embodiment
[0084] An agent for treating biodegradable synthetic yarns fabricated from the lactic acid polymer, which comprises 3 weight % of the aforesaid functional agent (K-6), 66 weight % of the aforesaid lubricant (L-2), 30 weight % of the aforesaid surfactant (S-1) and 1 weight % of the aforesaid subordinate component (E-1), and has a friction coefficient of 0.06.
Seventh Embodiment
[0085] An agent for treating biodegradable synthetic yarns fabricated from the lactic acid polymer, which comprises 5 weight % of the following functional agent (K-7), 74 weight % of the aforesaid lubricant (L-1), 19 weight % of the aforesaid surfactant (S-1) and 2 weight % of the following subordinate component (E-2), and has a friction coefficient of 0.08.
Functional Agent (K-7)
[0086] A polyether polyester compound having an average molecular weight of 8,000, which is obtained from dimethyl terephthalate/dimethyl 5-sulfoisophthalate/polyethylene glycol having an average molecular weight of 600/ethyelene glycol at a proportion of 0.95/0.05/0.9/0.1 by mole.
Subordinate Component (E-2)
[0087] Ethylene glycol.
Eighth Embodiment
[0088] An agent for treating biodegradable synthetic yarns fabricated from the lactic acid polymer, which comprises 5 weight % of the aforesaid functional agent (K-7), 40 weight % of the following lubricant (L-3) and 55 weight % of the aforesaid surfactant (S-2), and has a friction coefficient of 0.10.
Lubricant (L-3)
[0089] Octyl stearate.
Ninth Embodiment
[0090] The ninth embodiment of the present invention is directed to a method for the treatment of biodegradable synthetic yarns.
[0091] According to this method the agent for treating biodegradable synthetic yarns according to any one of the 1st to 8th embodiments of the present invention is first provided in a 10 weight % aqueous solution form. Then, the biodegradable synthetic yarns spun from the lactic acid polymer are applied with that aqueous solution in an amount of 0.8 weight % as calculated on the basis of said agent.
[0092] By way of example but not by way of limitation, the present invention will now be explained with reference to working examples, etc., in which “part” means “part by weight” and “%” is given % by weight.
EXAMPLE
Experimentation 1
Preparation of the Agent for Treating Biodegradable Synthetic Yarns
Example 1
[0093] 10 parts of the following functional agent (K-1), 75 parts of the following lubricant (L-1) and 15 parts of the following surfactant (S-1) were uniformly mixed together to prepare the following agent (P-1) for treating biodegradable synthetic yarns, with a friction coefficient of 0.09.
Functional Agent (K-1)
[0094] A polyether compound having an average molecular weight of 10,000, which was obtained by the random addition of ethylene oxide and propylene oxide to ethylene glycol at an ethylene oxide-to-propylene oxide proportion of 50/50 by mole.
Lubricant (L-1)
[0095] A 1/1 by-weight mixture of a polyether monol having an average molecular weight of 1,100, which was obtained by the random addition of ethylene oxide and propylene oxide to butyl alcohol at an ethylene oxide-to-propylene oxide proportion of 60/40 by mole and a polyether monol having a number-average molecular weight of 2,400, which was obtained by the random addition of ethylene oxide and propylene oxide to butyl alcohol at an ethylene oxide-to-propylene oxide proportion of 75/25 by mole.
Surfactant (S-1)
[0096] A 10/4/1 by-weight mixture of polyoxyethylene (with the number of repetition of oxyethylene unit being 5 and having an alkyl group having 12 carbon atoms) alkyl ether/sorbitan monooleate/sodium laurylsulfonate.
[0097] The friction coefficient of that agent was found in a 25° C. atmosphere having a relative humidity of 65% under a counter weight condition of 40 g/80 g, using a pendulum type oiliness friction tester manufactured by Shinko Zoki Co., Ltd.
Examples 2-19 & Comparative Examples 1-3
[0098] As in Example 1, the agents for treating biodegradable synthetic yarns according to Examples 2 to 19 and Comparative Examples 1 to 3 (P-2 to P-19 and R-1 to R-3) were prepared. Tabulated in Table 1 are the compositions, etc. of the agents for treating biodegradable synthetic yarns according to the examples inclusive of Example 1.
[0000]
TABLE 1
Agent for treating biogradable synthetic yarn
Composition
Functional
agent
Lubricant
Surfactant
Other
Oiliness
Use
Use
Use
Use
Friction
Item
Kind
Kind
amount
Kind
amount
Kind
amount
Kind
amount
coefficient
Example
1
P-1
K-1
10
L-1
75
S-1
15
3.09
2
P-2
K-2
16
L-2
62
S-1
21
E-1
1
4.07
3
P-3
K-3
11
L-1
74
S-1
15
5.10
4
P-4
K-3
5
L-1
40
S-2
55
6.11
5
P-5
K-6
1
L-1
42
S-2
57
7.08
6
P-6
K-6
3
L-2
66
S-1
30
E-1
1
8.06
7
P-7
K-7
5
L-1
74
S-1
19
E-2
2
9.08
8
P-8
K-7
5
L-3
40
S-2
55
10.10
9
P-9
K-10
20
L-4
30
S-2
50
11.13
10
P-10
K-1
10
L-1
75
S-3
15
12.09
11
P-11
K-3
0.5
L-3
79
S-1
20.5
13.18
12
P-12
K-2
10
L-3
60
S-4
30
14.10
13
P-13
K-2
5
L-1
74
S-5
20
E-2
1
15.10
14
P-14
K-6
2
L-2
65
S-4
30
E-1
3
16.06
15
P-15
K-6
2
L-1
71
S-5
24
E-2
3
17.07
16
P-16
K-4
22
L-1
59
S-1
19
18.13
17
P-17
K-5
8
L-2
66
S-2
26
19.10
18
P-18
K-8
1.5
L-3
60
S-1
39.5
20.16
19
P-19
K-9
2.2
L-4
69
S-2
29
0.07
Comparative
1
R-1
L-1
80
S-1
15
E-2
5
21.22
Example
2
R-2
K-1
35
L-1
50
S-1
15
22.07
3
R-3
L-3
65
S-5
30
E-2
5
0.25
[0099] In Table 1, the amounts of the agent components used are given by part.
[0100] K-1 is a polyether compund having an average molecular weight of 10,000, which was obtained by the random addition of ethylene oxide and propylene oxide to ethylene glycol at an ethylene oxide-to-propylene oxide proportion of 50/50 by mole.
[0101] K-2 is a polyether compound having an average molecular weight of 6,000, which was obtained by the random addition of ethylene oxide and propylene oxide to trimethylolpropane at an ethylene oxide-to-propylene oxide proportion of 70/30 by mole and in which hydrogen atoms in all hydroxyl groups of resulting polyether triol were substituted by methyl groups.
[0102] K-3 is a polyether compound having an average molecular weight of 3,500, which was obtained by the random addition of ethylene oxide and butylene oxide to ethylene glycol at an ethylene oxide-to-butylene oxide proportion of 70/30 by mole and in which hydrogen atoms in all hydroxyl groups of resulting polyether diol were replaced by decanoyl groups.
[0103] K-4 is a polyether compond having an average molecular weight of 3,300, which was obtained by the random addition of ethylene oxide and butylene oxide to butyl alcohol at an ethylene oxide-to-butylene oxide proportion of 70/30 by mole.
[0104] K-5 is a polyether compound having an average molecular weight of 19,000, which was obtained by the random addition of ethylene oxide and propylene oxide to trimethylolpropane at an ethylene oxide-to-propylene oxide proportion of 75/25 by mole and in which hydrogen atoms in all hydroxyl groups of resulting polyether triol were substituted by octadecanoyl groups.
[0105] K-6 is a polyether polyester compound having an average molecular weight of 20,000, which was obtained from a 1/1 by-mole mixture of dimethyl terephthalic acid and polyethylene glycol having an average molecular weight of 1,000.
[0106] K-7 is a polyether polyester compound having an average molecular weight of 8,000, which was obtained from a 0.95/0.05/0.9/0.1 by-mole mixture of dimethyl terephthalate, dimethyl 5-sulfoisophthalate, polyethylene glycol having an average molecular weight of 600 and ethylene glycol.
[0107] K-8 is a polyether polyester compound having an average molecular weight of 15,000, which was obtained from a 1/1/2/1 by-mole mixture of terephthalic acid, adipic acid, polyethylene glycol having an average molecular weight of 1,000 and polyethylene glycol monophenyl ether having an average molecular weight of 1,000.
[0108] K-9 is a polyether polyester compound having an average molecular weight of 45,000, which was obtained from a 3/3/1 by-mole mixture of dimethyl terephthalate, polyethylene glycol monophenyl ether having an average molecular weight of 600 and polyoxyethylene glycol triol having an average molecular weight of 500 obtained by adding ethyleneoxide to glycerin.
[0109] K-10 is an oxidized polyethylene wax having an average molecular weight of 2,400.
[0110] L-1 is a 1/1 by-weight mixture of polyether monol having an average molecular weight of 1,100, which was obtained by the random addition of ethylene oxide and propylene oxide to butyl alcohol at an ethylene oxide-to-propylene oxide proportion of 60/40 by mole and polyether monol having a number-average molecular weight of 2,400, which was obtained by the random addition of ethylene oxide and propylene oxide to butyl alcohol at an ethylene oxide-to-propylene oxide proportion of 75/25 by mole.
[0111] L-2 is a 1/2 by-weight mixture of polyether monol having an average molecular weight of 2,500, which is obtained by the random addition of ethylene oxide and propylene oxide to dodecyl alcohol at an ethylene oxide-to-propylene oxide proportion of 40/60 by mole and polyether diol having a number-average molecular weight of 1,000, which is obtained by the random addition of ethylene oxide and propylene oxide to ethylene glycol at an ethylene oxide-to-propylene oxide proportion of 80/20 by mole.
[0112] L-3 is octyal stearate.
[0113] L-4 is a 60/40 by-weight mixture of glycerol tri (12-hydroxystearate) and a mineral oil of 5×10 −6 m 2 /s.
[0114] S-1 is a 67/27/6 by-weight mixture of polyoxyethylene (n=5) lauryl ether, sorbintan monooleate and sodium dodecysulfonate.
[0115] S-2 is a 14/85/2 by-weight mixture of polyoxyalkylene (n=5) lauryl ether, decanoic ester of polyoxyethylene (n=4) lauryl ether, and dipotassium dodecenylsuccinic acid.
[0116] S-3 is a 70/10/20 by-weight mixture of polyoxyethylene (n=4) lauryl aminoether, lauryl dimethyl ammonioacetate and lauryl phosphate·octyltrimethyl-ammonium.
[0117] S-4 is a 27/67/6 by-weight mixture of polyoxyethylene (n=5) lauryl ether, polyoxyalkylene (n=20) hardened castor oil and polyoxyethylene (n=3) lauryl ether phosphoric ester potassium.
[0118] S-5 is a 40/40/20 by-weight mixture of polyoxyethylene (n=5) lauryl ether, polyoxyalkylene (n=4) diethylenetriamineisostearylamide and lauryl dimethylamine oxide.
[0119] E-1 is polyether-modified silicone.
[0120] E-2 is ethylene glycol.
Experimentation II
Oiling and Evalulation of each Agent with Respect to Biodegradable Synthetic Yarns
[0121] Oiling of each agent with respect to biodegradable synthetic yarns:
[0122] Lactic acid polymer chips having an average molecular weight 100,000, a melt flow rate of 25 g/10 min. at 210° C., a glass transition temperature of 64° C. and a specific gravity of 1.26 were fed into an extruder type melt spinning machine where they were melted at 210° C. After the hot melt was extruded from a spinneret and hardened by cooling, the resultant traveling yarns were oiled with a 10% aqueous solution obtained by diluting the agent for treating biodegradable synthetic yarns obtained in Experimentation 1 with water at an oiling amount as indicated in Table 2 on the basis of the agent for treating biodegradable synthetic yarns by means of a guide oiling method using a measuring pump. Thereafter, the yarns were bundled together on a guide, and wound at a speed of 2,800 m/min. without any mechanical drawing, thereby obtaining a plurality of 10 kg cakes comprising partially drawn yarns of 154-dtex 36-filaments. The obtained partially drawn yarns were found to have a tenacity of 2.8 g/dtx and an elongation of 78%.
[0000] Measurement of the coverage of the agent for biodegradable synthetic yarns:
[0123] According to JIS-L1073 (for synthetic yarn testing), the coverage of the agent for treating biodegradable synthetic yarns with respect to biodegradable synthetic yarns was measured using a mixed solvent of n-hexane/ethanol (50/50 by volume) as an extraction solvent. The results are enumerated in Table 2.
[0000] Evaluation of bulkiness:
[0124] Using a twisting system (employing a hard polyurethane rubber disk), the obtained partially drawn yarns were subjected to drawing and false twisting at a yarn traveling speed of 400 m/min. and a drawn ratio of 1.5 with a 2 m long heater on a twist side (at surface temperatures of 100° C. and 140° C. but without a heater on an untwisting side. The intended number of twisting was set at 2,800 T/m. Prior to winding, the obtained false-twisted yarns of 100 dtx 36 filaments were measured in terms of the number of twisting, using a twist monitor (Model TM-501 manufactured by Toray Industries, Inc.), and evaluated in terms of bulkiness on the following criteria. The results are set out in Table 2.
[0125] AA: the intended number of twisting, say 2,800 T/m, was achieved.
[0126] A: greater than 2,700 T/m but less than 2,800 T/m.
[0127] B: greater than 2,500 T/m but less than 2,700 T/m.
[0128] C: less than 2,500 T/m.
[0000] Evaluation of fuzzes:
[0129] Prior to winding, the obtained false-twisted yarns of 100 dtx 36-filaments were measured in terms of the number of fuzzes per hour using a fray counter (DT-105 manufactured by Toray Engineering Co., Ltd.), and evaluated on the following criteria. The results are set out in Table 2.
[0130] AA: no fuzz was found.
[0131] A: Five or less fuzzes were found.
[0132] B: greater than five but less than 10 fuzzes were found.
[0133] C: Ten or more fuzzes were found.
[0000] Evaluation of breaks:
[0134] After subjected to drawing and false twisting continuously over 10 days under the aforesaid conditions, the number of breaks per hour was evaluated on the following criteria. The results are shown in Table 2.
[0135] AA: no break was found.
[0136] A: one break was found per hour.
[0137] B: three breaks were found per hour.
[0138] C: five or more breaks were found per hour.
[0000] Measurement of tenacity of false-twisted yarns:
[0139] According to JIS-L1013, the tenacity of the obtained false-twisted yarns was evaluated as tensile tenacity-elongation property. The results are shown in Table 2.
[0140] AA: tenacity of 5.4 g/dtx or greater.
[0141] A: tenacity of greater than 5.0 g/dtx but less than 5.4 g/dtx.
[0142] B: tenacity of greater than 4.0 g/dtx but less than 5.0 g/dtx.
[0143] C: tenacity of less than 4.0 g/dtx.
[0000]
TABLE 2
Evaluation
Bulkiness
Fuzzes
Breaks
Tenacity
Oiling
Cond.
Cond.
Cond.
Cond.
Cond.
Cond.
Cond.
Cond.
Item
amount
1
2
1
2
1
2
1
2
Example
1
1.8
AA
AA
AA
AA
AA
AA
AA
AA
2
2.8
AA
AA
AA
AA
AA
AA
AA
AA
3
3.8
AA
AA
AA
AA
AA
AA
AA
AA
4
4.8
AA
AA
AA
AA
AA
AA
AA
AA
5
5.8
AA
AA
AA
AA
AA
AA
AA
AA
6
6.8
AA
AA
AA
AA
AA
AA
AA
AA
7
7.8
AA
AA
AA
AA
AA
AA
AA
AA
8
8.8
AA
AA
AA
AA
AA
AA
AA
AA
9
9.8
A
AA
AA
A
AA
A
AA
AA
10
10.8
A
AA
AA
A
AA
AA
AA
AA
11
11.8
A
AA
AA
A
AA
AA
AA
AA
12
12.8
A
AA
AA
A
AA
AA
AA
AA
13
13.8
A
AA
AA
A
AA
AA
AA
AA
14
14.8
A
AA
AA
A
AA
AA
AA
AA
15
15.8
A
AA
AA
A
AA
AA
AA
AA
16
16.8
A
AA
AA
A
AA
A
AA
AA
17
17.8
A
AA
AA
A
AA
A
AA
AA
18
18.8
A
AA
AA
A
AA
A
AA
AA
19
0.8
A
AA
AA
A
AA
A
AA
AA
Comparative
1
19.8
B
B
B
C
A
C
A
C
Example
2
20.8
A
A
C
C
C
C
A
A
3
0.8
C
B
C
C
B
C
A
C
[0144] In Table 2, the coverage of the agent, given in %, is defined with respect to biodegradable synthetic yarns.
[0000] Condition 1: heater temperature of 100° C.
Condition 2: heater temperature of 140° C.
[0145] While all of the fundamental characteristics and features and method of the present invention have been described herein, with reference to particular embodiments thereof, a latitude of modification, various changes and substitutions are intended in the foregoing disclosure and it will be apparent that in some instance, some features of the invention will be employed without a corresponding use of other features without departing from the scope of the invention as set forth. It should be understood that such substitutions, modifications, and variations may be made by those skilled in the art without departing from the spirit or scope of the invention. Consequently, all such modifications and variations are included within the scope of the invention as defined by the following claims. | An agent and method for treating biodegradable synthetic yarns fabricated from a polymer comprising lactic acid as a main component, which enable improved lubricity, cohesion, etc. to be so imparted to the biodegradable synthetic yarns that the yarns can be prevented from fuzzing and breaking at every step from spinning to down-stream step, especially at a false twisting step and improved in terms of bulkiness, providing yarns having improved mechanical properties in a stable manner. The agent of the invention comprises 0.1 to 30 weight % of a specific functional agent, and a lubricant and a surfactant in the total amount of 70 weight % or greater, and has a friction coefficient in the range of 0.04 to 0.35. | 3 |
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of U.S. Provisional Application No. 60/814,304 filed Jun. 16, 2006.
BACKGROUND OF THE INVENTION
[0002] Removable electric light assemblies for use on vehicles such as motorcycles, in ovens, and as lanterns have been described in the prior art, see, for example, U.S. Pat. Nos. 5,820,254, 6,461,010, and 7,014,459. Unlike conventional flashlights, these devices allow for mounting or placement of the light assembly in a location for use, and removal for storage, replacement, or installation.
[0003] As light sources in a closed or open environment, these known prior art devices present certain disadvantages. For example, the light assembly for the motorcycle cannot function as a discrete light source apart from the vehicle. Similarly, the oven light assembly cannot be removed for use as a light source away from the oven. In addition, while electric lanterns are portable and functional discrete devices, typical lanterns, like flashlights, are not designed to be mounted to a surface.
[0004] The present invention addresses the disadvantages of conventional removable electric lights by providing a discrete electric light that can be mounted for long-term use as a permanent or temporary fixture in an environment, and yet be easily removed without the use of tools for use as a portable light source.
SUMMARY OF THE INVENTION
[0005] The present invention provides a light assembly that is both portable and mountable. The light assembly can be attached to a surface as a fixed light source but is also easily removed to function as a portable light device. In particular, the light assembly of the invention combines a retaining element that is affixed to a surface but also releasably retains the light emitting element. The light emitting element unites with or detaches from the retaining element without the use of any tools and functions as a discrete portable light source when removed from the retaining element. The retaining element may be permanently or temporarily attached to a surface to easily add a light source where necessary or desired. The associated light emitting element remains removable and portable.
[0006] One object of this invention is to provide a light assembly that includes (1) a portable lamp unit having a light transmitting means, a power source, and an operating means for activating the power source, where the light transmitting means has at least one light source, such as an incandescent light, a halogen light, a fluorescent light, a high intensity discharge lamp, and/or a light emitting diode and/or a laser; and (2) a base unit having a retaining means to releasably hold the lamp unit and a fastening means to attach the base unit to a surface.
[0007] In the portable lamp unit of the light assembly, the power source can be one or more batteries or an external power source. The operating means of the lamp unit can further include an actuator connected to the power source and can be a string, a button, a slide switch, and/or a sensor. The lamp unit can also include a light permeable shell that encloses at least a portion of the lamp unit, where the shell has a screw-type, snap-type, or other type of connector for connecting to the lamp unit.
[0008] Another object of the invention is to provide a retaining means for the base unit of the light assembly that allows for the lamp unit to be slid into and out of the retaining means without locking such that the lamp unit is readily and easily removable. The retaining means can be a sleeve, a hook and loop fastener, a clip, a socket, a cavity, and/or a groove. The fastening means of the base unit of the light assembly can be an adhesive, a screw, a nail, a bolt, and/or a dowel. The base unit of the light assembly may be attached to a surface, such as, for example, a wall, ceiling, shelf, or door, either temporarily or permanently.
[0009] A further object of the invention is to provide a light assembly having a portable lamp unit having a light transmitting means, a power source, and an operating means for activating the power source, wherein the light transmitting means has at least one light source; and a base unit having a retaining means to releasably hold the lamp unit and a fastening means to attach the base unit to a surface. The operating means can activate the power source and the light transmitting means can have at least one light source. The retaining means can allow for the lamp unit to be slid in and out without locking and can have a sleeve, a hook and loop fastener, a clip, a socket, a cavity, and/or a groove. Also, the fastening means can be an adhesive, a screw, a nail, a bolt, and/or a dowel. In addition, the base unit can be permanently or temporarily attached to the surface which can be a wall, ceiling, shelf, and/or door.
[0010] Another object of the invention is to provide a light permeable shell for enclosing at least a portion of the lamp unit. The shell can have a connector for connecting to the lamp unit and the connector can be a screw-type connector and/or a snap-type connector.
[0011] An additional object of the invention is to provide the power source as at least one battery, the power source being activated by an actuator which can be a string, a button, a slide switch, and /or a sensor. Also, the light source can be an incandescent light, a halogen light, a fluorescent light, a high intensity discharge lamp, a light emitting diode, and/or a laser.
[0012] Another object of the present invention is to provide a method of using the light assemblies described above having the steps of: (a) mounting the base unit onto a surface; (b) sliding the lamp unit into the base unit; and (c) using the operating means to activate the power source. The method can also include the steps of (a) sliding the lamp unit out of the base unit; and (b) transporting the lamp unit.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] FIG. 1 shows a front perspective view of the lamp unit of one embodiment of the invention;
[0014] FIG. 2 shows a perspective view of the interior of the lamp unit of one embodiment of the invention;
[0015] FIG. 3 shows a top perspective view of the interior of the lamp unit of one embodiment of the invention;
[0016] FIG. 4 shows a bottom perspective view of a power source of one embodiment of the lamp unit of the invention;
[0017] FIG. 5 shows a front perspective view of the base unit of one embodiment of the invention;
[0018] FIG. 6 shows a rear perspective view of the base unit of one embodiment of the invention;
[0019] FIG. 7 shows a perspective view of a lamp unit releasably retained in the base unit of one embodiment of the invention;
[0020] FIG. 8 shows a side perspective view of the lamp unit of another embodiment of the invention with a light permeable shell; and
[0021] FIG. 9 shows a side perspective view of a light permeable shell of one embodiment of the invention with a screw-type connector.
DETAILED DESCRIPTION OF THE INVENTION
[0022] Referring to the drawings, FIG. 1 shows a discrete lamp unit 10 of one embodiment of the invention. The lamp unit 10 includes a light transmitting means 20 , a casing 30 enclosing a power source 40 ( FIG. 2 ), and an operating means 50 accessible from outside the casing 30 . The lamp unit 10 is portable, that is, capable of functioning independently. The light source 60 of the light transmitting means 20 can be any light source capable of illuminating an area, for example, an incandescent light, a halogen light, a fluorescent light, a high intensity discharge lamp, a light emitting diode, a laser, or any combination of these or other light sources.
[0023] In one embodiment shown in FIG. 3 , the light source 60 is a halogen bulb filled with krypton gas for longer life and less energy consumption. The light source 60 can be mounted directly to the casing 30 , but in one embodiment is attached by a screw-type connector 70 , which in turn is mounted on a platform 80 , as shown in FIGS. 2 and 3 . The electrical connection of the screw-type connector 70 to the power source 40 through a switch (not shown) is conventional.
[0024] The power source 40 within the casing 30 has at least one direct power source, such as one or more batteries 100 , as in FIG. 4 showing a bottom perspective view of an embodiment of the lamp unit, or an external power source attached through a receptacle in the casing 30 . Such an external power source can be a transformer from an alternating current source such as a conventional electric outlet (not shown), or a combination of power sources. The external power source is particularly useful when the light unit is in the base unit 200 ( FIG. 5 ) and the base unit is mounted near a conventional outlet. FIG. 4 shows a door 110 that provides access to the power source 40 such as one or more batteries inside the casing 30 .
[0025] The operating means 50 of the lamp unit 10 has an actuator (not shown) that allows activation of the power source 40 . In one embodiment, the operating means 50 is a string. However, any switch actuator can be used, for example, push button(s), slide switches, sensors, et cetera.
[0026] FIG. 5 shows the base unit 200 of one embodiment of the invention. The base unit 200 has a retaining means 210 that allows the lamp unit 10 to be slid in, without locking, so that the lamp unit 10 can be removably mounted by means of the base unit 200 , or easily slid out as a separate, portable device. In one embodiment, the retaining means 210 is at least one sleeve adapted to receive the casing 30 of the lamp unit 10 . In another embodiment, the base unit 200 has at least two retaining means 210 adapted to receive the lamp unit 10 . Other retaining means, such as, for example, hook and loop fasteners, clips, sockets, cavities, grooves, et cetera can also be employed.
[0027] The base unit 200 shown in FIG. 5 also has a fastening means 220 for attaching the base unit 200 to a surface such as a wall, ceiling, shelf, or door. The fastening means 220 shown in FIG. 5 has apertures 230 that can accommodate one or more screws, nails, bolts, dowels, or other means to attach the base unit 200 to a surface.
[0028] FIG. 6 shows a rear perspective view of one embodiment of the base unit 200 . The drawing shows the back of the retaining means 210 and the fastening means 220 . In one embodiment, the fastening means 220 can accommodate an adhesive such as a two-sided adhesive pad (not shown) for temporarily or permanently attaching the base unit 200 to a surface instead of or in addition to the fastening means 220 .
[0029] FIG. 7 shows the present invention as an assembly of the lamp unit 10 and the base unit 200 . The drawing illustrates the lamp unit 10 sliding into place, guided by the retaining means 210 of the base unit 200 , such that the retaining means 210 releasably holds the lamp unit 10 by the casing 30 . FIG. 7 also shows the operating means 50 of the lamp unit 10 as a string. The string connects to a conventional switch (not shown) for the power source 40 , such that pulling the string 50 reversibly activates the power source 40 to provide or to stop providing power to the light transmitting means 20 .
[0030] FIGS. 7 and 8 show a light permeable shell 250 that encloses at least a portion of the lamp unit 10 . In an embodiment, the shell 250 is formed from a clear or translucent plastic to appear as a conventional light bulb envelope. The shell 250 is attached to the casing 30 by a connector 260 ( FIG. 9 ), which may be a screw-type, a snap-type, or another type of connector. In one embodiment, the connector 260 is complementary to a connector (not shown) formed in the casing 30 to provide for a reversible attachment. To replace the light source 60 of the light transmitting means, one need only unscrew the shell 250 , replace the light source 60 and reattach the shell 250 . FIG. 9 further shows a side perspective view of a light permeable shell 250 separated from the lamp unit 10 and base unit 200 .
[0031] While the present invention has been described with respect to preferred embodiments, those skilled in the art will appreciate that various adaptations and modifications of the embodiments may be made without departing from the scope and spirit of the invention. Therefore, it is to be understood that the invention may be practiced other than as specifically described above, within the scope of the appended claims. | A light assembly includes a portable lamp unit that functions alone as a light source or may be combined with a base unit for permanent or temporary attachment to a surface. The lamp unit has a light transmitting means, a power source, and an operating means that together provide a portable light source. When associated with the base unit, the lamp unit becomes removably retained in the base unit, providing for use of the lamp unit at a fixed location, while remaining easily removable for portable use. | 5 |
FIELD OF THE INVENTION
[0001] The invention relates generally to door latches. More specifically, the invention relates to a dual functioning latching apparatus that can maintain a door in a closed position through the interaction between a nose on the latch with a striker plate. The latch of the invention provides a user with options for disengaging the latch with the door frame permitting the user to operate the latch and door in a variety of ways. More specifically, the invention relates to a door latch for a all season door such as a storm or screen door used in conjunction with a main entry door installation. Such a latch can be installed on the surface of the door and can maintain the screen door in a closed position. Such all season doors, storm doors or screen doors are typically manufactured of thinner material than common entry doors and can comprise windows, insulating systems, gaskets, closure systems and other elements common to screen doors or storm doors in conjunction with the dual function latch of the invention.
BACKGROUND OF THE INVENTION
[0002] Door latching apparatus has been a rapidly evolving technology for use in primary entry doors and secondary doors such as all season doors doors. The primary function of the door latch, or catch, is to maintain a door in a closed position when not in use by engaging a strike plate. The door latch however, should respond to the application of a force that moves the latch in such a way to disengage the strike to open the door easily. Once the force is released, the latch should maintain a secure and safe closure, even when the latch is not locked.
[0003] Although door latches are known and generally function adequately for their intended purposes, some problems remain. One problem stems from the fact that door latches typically operate in a limited and specific manner. For example, some prior art latches operate in response to rotational forces applied to a handle. Others operate when a user pushes on a handle. Naturally, a user can become accustomed to a certain type of latch mechanism after repeated use. A broad array of closure systems have been used in configuring all season doors, storm doors or screen doors over the years. Simple closures have been used such as simple hook and eye closure systems, spring loaded compression systems and with simple hardware systems. Many screen doors are not latched at all and simply are maintained in a closed position with a spring loaded device that closes the door after its operation. Certain all season doors have been manufactured using either a latch that has an opening by pressing on a lever arm that disengages the latch nose from the strike. Still other doors have latch mechanisms that rotate to withdraw the latch nose from the strike thus permitting the operation of the door. Many users become familiar with one or the other mode of operating of the door and can often be confused when confronted with a door having an unfamiliar operating mode. Such problems can be minor annoyances, however, they can also provide safety concerns if rapid exiting of a location in the presence of some hazard is required.
[0004] Further, encounters with non-familiar types of latches can be awkward, especially for elderly users. In situations where a user has a limited range of motion in their wrists or hands, it may become necessary to install a new latch that is better suited to the user's physical capabilities. In nursing home environments, it would not be feasible to replace each latch to accommodate a specific user. Accordingly, a latch system capable of accommodating a broader range of user preferences and physical capabilities is desirable.
[0005] Miller U.S. Pat. No. 4,632,439 shows an adjustable latch system that is operated by either compressing a button in a door handle or by compressing a lever arm on the interior of the door to operate the latch nose. This system is representative of conventional systems typically using a force normal to the surface of the door operating either a lever arm or a compression button. Certain handle mechanisms in the prior art are configured such that the handle can move in both a rotation mode and in a normal mode with respect to the surface of the mounting surface. However, in all of these systems, such handles do not operate to open or close a door system when operated in both a rotational and a normal force mode. Examples of these types of handles are shown in Nehls U.S. Pat. No. 2,141,659; Dickason U.S. Pat. No. 2,278,534; Sanderlin et al. U.S. Pat. No. 2,605,648; and Mayer U.S. Pat. No. 1,684,499. Fujiya U.S. Pat. No. 4 , 480 , 451 shows a rotational latch having an interior lock operable using a handle that can move in more than one direction. Lastly Butterfield et al. U.S. Pat. No. 4,072,331 shows a “three-way” actuation means. This actuation means provides a variety of operating levers that can be used to operate the door. No one lever has the capability of permitting operation of the door with the operation of the handle in both a rotational and axial mode.
SUMMARY OF THE INVENTION
[0006] The present invention is directed to a dual functioning latching apparatus that can maintain a door, preferably an all season door, in a closed position through the interaction of a latch nose with a striker plate. A user can apply a number of different forces to the latch handle to disengage the nose from the striker plate. In a rotational function of the latching apparatus, the user may apply a force to move the handle in a rotational fashion in a plane that is substantially parallel to the door surface to retract the latch nose. The latching apparatus is also configured such that the user at his option can apply an axial force to the handle that is substantially normal to the door surface so that one end of the handle moves toward the door to retract the latch nose. This dual function latching assembly provides a user with the option of either opening the door by exerting a force on the latch assembly substantially normal to the door surface or by exerting a rotational force against the matching assembly in a plane substantially parallel to the door surface.
[0007] With regard to the rotational function of the latching apparatus, the rotational movement of the handle corresponds to the rotational movement of the latch nose about the access of the spindle. In the first position, the latch nose can contact a strike on the door frame. The rotation of the handle in either a clockwise or counterclockwise motion rotates the latch nose to a position that is away from the strike so a user can open the door. When the user is not applying a force to the handle, a turning axis spring can return the handle and latch nose to the first position.
[0008] The retractional function of the latching apparatus functions independently of the rotational function. For example, the user can open the door by applying a force in a direction substantially normal to the door surface. In one embodiment, a first spring biases the handle in an extended position. The user can depress the handle on the latching apparatus. This action displaces the handle so that it no longer contacts the latch nose. The displacement of the handle enables the latch nose to pivot toward the spindle and away from the strike on the doorframe. This pivoting action is caused by a second spring that is fastened to the latch nose and the spindle assembly. The second spring biases the latch nose away from the strike on the doorframe. When the user is not applying a force to the handle, the first spring can return the handle to the extended position and overcome the force of the second spring to displace the latch nose to its extended position.
[0009] In an alternative embodiment, the latch assembly includes a locking lever. The locking lever has a locked position and an unlocked position operatively connected to the spindle/handle assembly. The lock lever is configured for contacting a corresponding feature on the spindle to substantially prevent axial or rotational movement of the spindle. Similarly, the lock lever is also configured to contact the latch nose when the lock lever is in the locked position. The contact between the lock lever and the latch nose prevents the latch nose from moving toward the spindle and clearing the strike on the doorframe. For the purpose of this patent application, the term “strike” refers to a mechanical element installed on a door frame that can interact with the latch nose of the latch of the invention to maintain the door in a closed position. Strikes are commonly simple planar metal elements having a curved surface to facilitate the engagement and disengagement of the latch nose with the strike surface. For the purpose of this patent application the term “to detract the latch nose from the strike” typically implies that the latch nose is removed from an engaging position with respect to the strike either through a rotational force placed on the handle or through a axial force placed on the handle in a direction normal to the surface of the door. In this application, the term “axial force” relates to a force directed in parallel to the axis of rotation of the latch and acts unlatch in a direction towards the surface of the door. The term “all season door” refers to a door used in conjunction with a main entry door and can be a storm door a screen door or other door that provides added insulation, insect resistance, ease of use, air circulation or other feature in an opening having a entry door.
[0010] The above summary of the present invention is not intended to describe each disclosed embodiment or every implementation of the present invention. The figures and the detailed description that follows exemplify these embodiments more particularly.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] The invention may be more completely understood in consideration of the following detailed description of various embodiments of the invention in connection with the accompanying drawings, wherein like numerals represent like parts throughout several views, in which:
[0012] [0012]FIG. 1 is a partially exploded front view of a latch assembly of the present invention;
[0013] [0013]FIG. 2 is an exploded front view of the head and spindle assembly of the present invention;
[0014] [0014]FIG. 3 is an exploded front view of the base assembly of the present invention;
[0015] [0015]FIG. 4 is a front view of the turning axis hub of the present invention;
[0016] [0016]FIG. 5 is a side view of the turning axis hub of the present invention;
[0017] [0017]FIG. 6 is a side view of the latch nose of the present invention;
[0018] [0018]FIG. 7 is a front view of the latch nose of the present invention;
[0019] [0019]FIG. 8 is a top view of the latch base of the present invention;
[0020] [0020]FIG. 9 is a side view of the latch base of the present invention;
[0021] [0021]FIG. 10 is a bottom view of the latch base of the present invention;
[0022] [0022]FIG. 11 is a front view of the stator of the present invention;
[0023] [0023]FIG. 12 is a top view of the spindle head of the present invention;
[0024] [0024]FIG. 13 is a side view of the spindle head of the present invention;
[0025] [0025]FIG. 14 is a front view of the spindle head of the present invention;
[0026] [0026]FIG. 15 is a front view illustrating handle positions when a push force is applied to the latch assembly of the present invention;
[0027] [0027]FIG. 16 is a side view illustrating the handle positions when a twist force is applied to the latch assembly of the present invention;
[0028] While the invention is amenable to various modifications in alternative forms, the specifics thereof have been shown by way of example in the drawings and will be described in detail. The intention is not limited to the particular embodiments described. On the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0029] The door latch apparatus of the invention is configured to maintain a hinged door in a closed position by engaging a strike. The latching apparatus is capable of being mounted on the surface of the door comprising a latch nose and a handle. The latching apparatus is configured such that the user can disengage the latch in either of two different operating modes. First the latch can be disengaged from the strike by the application of rotational force in a plane parallel to the surface of the door. As the handle is moved in that rotational direction, the latch nose is moved away from the strike to disengage the strike permitting the user to operate the door to an open position. The latch also has the capability of being operated in a substantially different mode for a user that expects to be able to operate the door in a different mode. In this mode, the user compresses the handle by placing an axial force on the handle directed towards the surface of the door in a direction normal to the door. As the handle is compressed by this axial force, the handle is coupled with the latch nose through a lever and spring mechanism in a way such that the nose is retracted from the strike. As the operator continues to press the handle in this mode, the door can be operated to an open position. In this way, the latch mechanism of the invention provides a dual operating function in which the dual operating mode can permit a user to operate the door in both common operating modes. The nose, handle, strike, spindle, mounting materials, fasteners and other component parts can be made of conventional structural materials. Commercially available metals, thermoplastics, composites and coatings can be used in the manufacture of the functional unit of the claims.
[0030] Referring to the drawings, wherein like reference numerals refer to like parts throughout the several views, FIG. 1 shows a partially exploded view of a latch assembly 100 of the present invention. The handle 101 is shown as a substantially elongated member with a first end that is not in contact with the spindle head 109 and a second end that contacts the spindle head 109 at pivot 106 . The portion of handle 101 contacting the pivot 106 may have an aperture. The aperture on the handle 101 can be a variety of dimensions. In a preferred embodiment, the diameter of the aperture is at least 0.1 inches (2.5 mm). This dimension permits a fastener to pass through the aperture and the pivot that is a sufficient size and strength to withstand the force of a user opening the door 122 .
[0031] The handle 101 , latch nose 102 , spindle head 109 , and spindle 110 can be manufactured from a variety of materials including wood, metal, or thermoplastics. In any case, the material should be rigid enough to resist deformation and strong enough to withstand repeated forces from several directions under a variety of operating conditions. Handle 101 can comprise a variety of shapes based on the user's physical capabilities and aesthetic preferences. However, it is desirable to select a handle 101 that is long enough to move the latch nose 102 with relatively little effort. In most cases, handle 101 will be at least 2.5 inches (6.4 cm.) long, although in some embodiments, handle 101 can be up to 5 inches (12.7 cm.) long. Handle 101 can be straight or curved, and have a variety of cross sectional profiles based on the aesthetic preferences of the user. The cross-sectional area of handle 101 should preferably be rigid enough to withstand a variety of forces from several directions. In a preferred embodiment, the cross sectional area of handle 101 should be at least 0.04 in 2 (0.26 cm 2 ).
[0032] Spindle 110 can be slidably inserted into spindle head 109 at housing 104 . Spindle 110 can comprise a variety of shapes and dimensional configurations depending upon the thickness of the door 122 and the housing 104 . Spindle 110 can have a substantially elongated shape, with a substantially square cross-sectional profile. Spindle 110 should be able to withstand the repeated torque applied by a user against torsion spring 132 . In a preferred embodiment, spindle 110 should be at least 2 inches (5 cm) long and have a cross sectional area of at least 0.097 in 2 (0.62 cm 2 ). Spindle 110 is preferably fabricated from a metallic or thermoplastic material.
[0033] Spindle 110 can then be secured to housing 104 using a variety of methods. In a preferred embodiment, a pin 107 extends through slot 113 in the side of housing 104 and into spindle recess 112 . The interaction of pin 107 and slot 113 secures spindle 110 into housing 104 so that spindle 110 cannot exit housing 104 , or rotate relative to housing 104 . In an alternative embodiment, spindle 110 can be secured into housing 104 with a press fit between the spindle head 109 and housing 104 .
[0034] Latch nose 102 may be rotatably fastened to spindle head 109 at rivet aperture 105 b on spindle head 109 and rivet aperture 105 a on latch nose 102 . Once rivet apertures 105 a and 105 b are properly aligned, a rivet or other suitable fastener may be inserted through rivet apertures 105 a and 105 b to rotatably secure the latch nose 102 to the spindle head 109 . Rivet aperture 105 may be located in multiple locations, with a variety of dimensions. It is desirable for rivet aperture 105 a to be large enough to permit a fastener of suitable strength to pass therethrough. In a preferred embodiment, rivet aperture 105 a can have a diameter of 0.125 inches (3.2 mm). The diameter of rivet aperture 105 b should be large enough to correspond to the dimension of rivet aperture 105 a . In the preferred embodiment, rivet aperture 105 b can have a diameter as small as 0.1 inches (2.5 mm).
[0035] Latch nose 102 has surface 111 suitably arranged for contacting a corresponding strike 124 extending from a doorframe 123 . Surface 111 is preferably at least 45° relative to the surface of the door frame. Surface 111 and strike 124 should be manufactured from a material that is wear resistant. In a preferred embodiment, the surface 111 on the latch nose 102 is biased toward the spindle 110 by a spring 103 . The spring 103 may be secured to the latch nose 102 by a stud 108 located on the interior surface of latch nose 102 . Stud 108 can be molded from the same material as latch nose 102 . The size of stud 108 can vary depending on the size of spring 103 . For example, stud 108 may be 0.126 inches (3.2 mm) in diameter.
[0036] Spring 103 may be secured to the spindle head 109 or housing 104 by attaching the spring 103 to the end of the pin 107 that is protruding from the housing 104 . When a user is not applying a force to the handle 101 the handle 101 is in an extended position (shown in FIG. 1). When a user is applying a force to the handle 101 that is normal to the surface of the door, the handle 101 is in a retracted position (shown with dashed lines in FIG. 15). A pivot spring may be located at pivot 106 that biases the handle 101 in an extended position. Handle 101 and latch nose 102 are rigidly in contact with one another when handle 101 is in an extended position. When a user applies a force normal to handle 101 such that handle 101 moves to a retracted position, latch nose 102 is permitted to rotate towards spindle 110 due to the force of spring 103 . When the force normal to handle 101 is no longer applied, the pivot spring should be strong enough to overcome the force of spring 103 acting on latch nose 102 and return the handle 101 to the extended position.
[0037] In an alternative embodiment, the spring 103 may be secured to the latch nose 102 by inserting the first end of spring 103 over a stud 108 located on the interior surface of latch nose 102 . The interior diameter of the first end of spring 103 and stud 108 can be configured to create a tight fit. Similarly, the spring 103 may be secured to the spindle head 109 or housing 104 by inserting the second end of spring 103 over the end of the pin 107 that is protruding from the housing 104 .
[0038] With reference to FIG. 2, the spindle 110 to spindle head 109 assembly is shown with dashed lines representing hidden features in the corresponding parts. For example, spindle recess 112 is shown on spindle 110 . Spindle 110 can be inserted into housing recess 114 on spindle head 109 . Housing recess 114 is configured so that when spindle 110 is inserted into the housing recess 114 , spindle recess 112 aligns with slot 113 on the spindle head 109 . Spring pin 107 can then be inserted into slot 113 and spindle recess 112 , which locks spindle 110 into housing recess 114 . It should be appreciated that the spindle 110 to spindle head 109 assemblies can comprise many different embodiments while falling within the scope of this invention. For example, the spindle recess 112 can consist of a drilled hole in the side of the spindle 110 , or it could consist of a milled groove running the entire circumference of spindle 110 . In an alternative embodiment, spindle 110 would not contain a spindle recess 112 . In that situation, spindle 110 could be press fit into housing recess 114 or secured in place with the friction of spring pin 107 inserted into slot 113 . In a preferred embodiment, spindle recess 112 is at least 0.15 inches (3.8 mm) deep and at least 0.12 inches (3.0 mm) in diameter. The center of spindle recess 112 can preferably be located at least 0.12 inches 3.0 mm from one end of the spindle 110 .
[0039] An exploded side view of the base assembly 130 is shown in FIG. 3. Base assembly 130 includes a turning axis hub 136 extending outward from the base assembly 130 and a snap ring groove 134 recessed in the base assembly 130 . Base assembly 130 can be inserted into latch base 131 so that the turning axis hub 136 contacts the surface of latch base 131 . Then, torsion spring 132 can be inserted over base assembly 130 past snap ring groove 134 . Torsion spring 132 biases the rotation of the base assembly 130 in its inserted position relative to the latch base 131 . Moreover, torsion spring 132 biases handle 101 in the relaxed position, shown as the solid line handle 101 in FIG. 16.
[0040] In a preferred embodiment, snap ring groove 134 is at least 0.05 inches (1.3 mm) in length. Turning axis hub 136 can preferably extend outward from the base assembly, to a diameter of at least 1.2 inches (30 mm). The base assembly 130 is most preferably at least 1 inch (25 mm) long when measured in its axial dimension. The portion of the base assembly 130 , on the side of the turning axis hub 136 toward the snap ring groove 134 can preferably measure at least 0.5 inches (13 mm) along the axial dimension. Similarly, the portion of the base assembly 130 , on the side of the turning axis hub 136 away from the snap ring groove 134 can preferably measure at least 0.3 inches (7.6 mm) along the axial dimension. The turning axis hub 136 can measure at least 0.05 inches (1.2 mm) along the axial dimension. The turning axis hub 136 should preferably be located at least 0.4 inches (10 mm) from the snap ring groove 134 . The base assembly can preferably be manufactured from a wear resistant metal or thermoplastic material.
[0041] When a user exerts a rotational force against the handle 101 in a plane substantially parallel to the door surface, handle 101 moves to either the counterclockwise position 101 ′ or the clockwise position 101 ″. In a preferred embodiment, the counterclockwise position 101 ′ of the handle and the clock-wise position 101 ″ of the handle are less than 50° from the relaxed position of the handle 101 , shown as a solid line on FIG. 16. The position of the latch nose 102 moves relative to the handle 101 . When the handle 101 is in the counterclockwise position 101 ′ or clockwise position 101 ″, the latch nose is able to clear the strike 124 on the surface of the door frame 123 , and the user is able to open the door 122 . In a preferred embodiment, the latch nose 102 can clear the strike 124 when the latch nose is rotated less than 50° in response to a rotation of the handle 101 .
[0042] Stator 133 , shown in FIG. 11, is inserted over base assembly 130 so that it secures torsion spring 132 in place. Stator 133 contains at least one extension 136 that protrudes outward from stator 135 . Extension 136 is useful for stabilizing stator 135 and torsion spring 132 . In one embodiment, the ends of torsion spring 132 can catch in notch 136 . Notch 136 provides a surface of resistance that is useful in biasing the torsion spring 132 . Then, snap ring 135 is secured to snap ring groove 134 and locks the torsion spring 132 and stator 133 in place.
[0043] The latch base 131 is shown in FIGS. 8, 9, and 10 . Latch base 131 contains a cavity 182 with a supporting ring 183 surrounding the cavity 182 . The diameter of cavity 182 should be large enough so that base assembly 130 can pass there through, allowing turning axis hub 136 to contact supporting ring 183 . Preferably, cavity 182 can be at least 0.59 inches (15 mm) in diameter. The outer portion of supporting ring 183 can preferably be at least 1.2 inches (30 mm) in diameter.
[0044] At least one mounting aperture 181 is located on the latch base 131 at a point adjacent to the supporting ring. Mounting aperture 181 should be large enough so that a fastener of suitable strength can pass there through. For example, mounting aperture 181 should preferably be at least 0.17 inches (4.3 mm) in diameter. The latch base 131 can be mounted to a door by inserting a fastener of suitable strength through the mounting aperture 181 . In a preferred embodiment, the latch base 131 is mounted to a door by inserting screws through mounting apertures 181 and 182 so that they are tightly affixed to the door. Alternatively, the latch base 131 can be mounted to the door with adhesive. The shape of the latch base can vary considerably based on aesthetic considerations. Latch base 131 can include notch 184 that can provide a surface that is useful in preventing rotation of latch base 131 relative to spindle 110 . In a preferred embodiment, notch 184 is at least 0.19 inches (4.8 mm) wide and 0.06 inches (1.5 mm) deep.
[0045] Spindle 110 of the latch assembly 100 can be inserted into the cavity 182 and through a similarly aligned aperture in the door so that the supporting ring 183 contacts the housing 104 and an end of the spindle 110 is exposed on the side of the door opposite the handle. A second latch base and second handle can then be slid over the exposed end of spindle 110 so that the latch nose 102 can be moved from both sides of the door.
[0046] [0046]FIG. 15 shows a first operable condition of the latch assembly 100 in which the latch nose 102 is moved by retracting the latch nose 102 in response to a force substantially normal to the door surface. The retracted position of the handle 101 and latch nose 102 are shown outlined in FIG. 15. The extended position of the handle 101 is substantially parallel to the surface of the door, and is shown with a solid outline on FIG. 15. In the extended position, the handle 101 makes contact with the latch nose 102 and biases the latch nose 102 toward the door. When the handle 101 is in the retracted position, the latch nose 102 is permitted to retract due to the force of the spring 103 . In a preferred embodiment, the retracted position of the handle is less than 50° from the extended position of the handle.
[0047] A second operable condition of the latch assembly 100 is shown in FIG. 16. In the second operable condition, the latch nose 102 can be moved in response to a force in a plane substantially parallel to the door surface. The rotatable latch nose 102 and handle 101 position are shown outlined in FIG. 16. The user can rotate the handle 101 in either a clockwise or counterclockwise manner relative to the spindle 110 . The rotation of the latch nose 102 corresponds to the rotation of the handle 101 . When the user is not applying a force to the handle 101 , torsion spring 132 biases the handle 101 and the latch nose 102 so that the latch nose 102 is located toward the strike on a door frame (shown as a solid line latch nose 102 on FIG. 16). In a preferred embodiment, the counterclockwise position of the handle and the clockwise position of the handle are less then 50° degrees from the relaxed position of the handle 101 .
[0048] The above specification provides a complete description of the manufacture and use of the invention. Since many embodiments of the invention can be made without departing from the spirit and scope of the invention, the invention resides in the claims hereinafter appended. | A door latch assembly configured to maintain an openable door in a closed position using a nose portion interacting with a striker plate, the latch assembly configured for opening the door through either moving the nose portion in response to a force in a plane substantially parallel to the door surface or by retracting the nose portion in response to a force substantially normal to the door surface. Such a dual function latching assembly provides a user with the option to either open the door by exerting a force on the latch assembly substantially normal to the door surface or by turning the latch assembly by exerting a rotating force against the matching assembly in a plane substantially parallel to the door surface. | 4 |
TECHNICAL FIELD
The present invention relates to modified cellulases. More specifically, the invention relates to modified Family 6 cellulases with improved thermostability, alkalophilicity and/or thermophilicity. The present invention also relates to genetic constructs comprising nucleotide sequences encoding for modified Family 6 cellulases, methods for the production of the modified Family 6 cellulase from host strains and the use of the modified Family 6 cellulases in the hydrolysis of cellulose.
BACKGROUND OF THE INVENTION
The most abundant polysaccharide in the biosphere, cellulose, consists of D-glucose units linked together in linear chains via β-1,4 glycosidic bonds. These chains can vary in length and often consist of many thousands of units. Cellulose chains form numerous intra- and intermolecular hydrogen bonds, which result in the formation of insoluble cellulose microfibrils. This crystalline cellulose is a recalcitrant material with a natural half-life of over five million years.
In order to access this important renewable carbon source, microorganisms, such as bacteria and fungi, produce a cocktail of enzymes to break down crystalline cellulose into glucose. Three general classes of cellulase enzymes act synergistically to hydrolyze the crystalline cellulose into the simple energy source glucose. Endo-β-1,4-glucanases (EC 3.2.1.4) randomly hydrolyze amorphous regions of crystalline cellulose generating oligosaccharides of various lengths and consequently new chain ends. Cellobiohydrolases (or exo-β-1,4-cellobiohydrolase, EC 3.2.1.91) hydrolyze processively cellobiose units from one end of the cellulose chain. Finally, β-1,4-glucosidases (EC 3.2.1.21) hydrolyse cellobiose into glucose.
Most cellobiohydrolases and endo-β-1,4-glucanases are multidomain proteins consisting of a catalytic core domain and a cellulose-binding domain separated by a flexible linker region. The cellulose-binding domain promotes adsorption of the enzyme to regions of the cellulosic substrate (Tomme, P., et al. 1988 . Eur. J. Biochem 170:575-581; Lehtio J., et al. 2003 Proc. Natl. Acad. Sci. USA. 100:484-489), while the catalytic core domain is responsible for the cleavage of cellulose. The linker region may ensure an optimal interdomain distance between the core domain and the cellulose-binding domain (Srisodsuk M., et al. 1993 . J. Biol. Chem. 268:20756-20761).
The catalytic domains are classified into the glycoside hydrolase families based on amino acid sequence similarities whereby a family comprises enzymes having similar fold and hydrolytic mechanisms but may differ in their substrate specificity. Trichoderma reesei contains known cellulase genes for two cellobiohydrolases, i.e., Cel7A (also known as CBH1, which is a member of Family 7) and Cel6A (CBH2), at least eight endo-β-1,4-glucanases, i.e., Cel7B (EG1), Cel5A (EG2), Cel12A (EG3), Cel61A (EG4), Cel45A (EG5), Cel74A (EG6), Cel61B (EG7), and Cel5B (EG8), and at least seven β-1,4-glucosidase, i.e., Cel3A (BG1), CellA (BG2), Cel3B (BG3), Cel3C (BG4), CellB (BG5), Cel3D, and Cel3E (Foreman, P. K., et al. 2003 . J. Biol. Chem. 278:31988-31997).
T. reesei Cel6A (or TrCel6A) is one of the two major cellobiohydrolases secreted by this fungus and has been shown to be efficient in the enzymatic hydrolysis of crystalline cellulose. TrCel6A is a member of glycoside hydrolase Family 6, which comprises enzymes that hydrolyse β-1,4 glycosidic bonds with inversion of anomeric configuration and includes cellobiohydrolases as well as endo-β-1,4-glucanases. The three dimensional structures of TrCel6A (Rouvinen J., et al. 1990 . Science 249:380-386. Erratum in: Science 1990 249:1359), Thermobifida fusca endo-β-1,4-glucanase Cel6A (TfCel6A, Spezio M., et al. 1993 . Biochemistry. 32:9906-9916), Humicola insolens cellobiohydrolase Cel6A (HiCel6A, Varrot, A., et al. 1999 Biochem. J. 337:297-304), Humicola insolens endo-β-1,4-glucanase Cel6B (HiCel6B, Davies, G. J., et al. 2000 . Biochem. J. 348:201-207), and Mycobacterium tuberculosis H37Rv Cel6A (MtCel6A, Varrot. A., et al. 2005 . J. Biol. Chem. 280:20181-20184) are known.
Applications of cellulase enzymes in industrial processes are numerous and have proven commercially useful within the textile industry for denim finishing and cotton softening; in the household and industrial detergents for color brightening, softening, and soil removal; in the pulp and paper industries for smoothing fiber, enhancing drainage, and de-inking; in the food industry for extracting and clarifying juice from fruits and vegetables, and for mashing; in the animal feed industry to improve their nutritional quality; and also, in the conversion of plant fibers into glucose that are fermented and distilled to make low CO 2 cellulose ethanol to reduce fossil fuel consumption, which is an emerging industry around the world (e.g. Gray K. A., et al. 2006 . Curr. Opin. Chem. Biol. 10:141-146).
In order to obtain enzyme variants with improved stability properties, three strategies have generally been used within the art: 1) isolation of thermophilic enzymes from extremophiles, residing in severe environments such as extreme heat or cold, high salt concentrations or high or low pH conditions (e.g. U.S. Pat. No. 5,677,151 U.S. Pat. Appl. No. 20060053514); 2) protein engineering by rational design or site-directed mutagenesis, which relies on sequence homology and structural alignment within a family of proteins to identify potentially beneficial mutations using the principles of protein stability known in the art (reviewed in: Eijsink, V. G., et al. 2004 . J. Biotechnol. 113:105-20.); and 3) directed evolution involving the construction of a mutant library with selection or screening to identify improved variants and involves a process of iterative cycles of producing variants with the desired properties (recently reviewed in: Eijsink V G, et al. 2005 . Biomol. Eng. 22:21-30). This approach requires no structural or mechanistic information and can uncover unexpected beneficial mutations. Combining the above strategies has proven to be an efficient way to identify improved enzymes (Chica R. A., et al. 2005 . Curr. Opin. Biotechnol. 16:378-384).
Using rational design, Zhang et al. (Zhan S et al., 2000 . Eur. J. Biochem. 267:3101-15), introduced a new disulfide bond across the N- and C-terminal loops from TfCel6B using two double mutations, and four glycine residue mutations were chosen to improve thermostability. None of the mutations increased thermostability of this cellobiohydrolase and most mutations reduced thermostability by 5-10° C. Surprisingly, the double mutation N233C-D506C showed a decrease of 10° C. for the T 50 (Zhang S et al., 2000 . Eur. J. Biochem. 267:3101-15), or a slight increase of about 2° C. for the T 50 (Ai, Y. C. and Wilson, D. B. 2002. Enzyme Microb. Technol. 30:804-808). Wohlfahrt (Wohlfahrt, G., et al. 2003 . Biochemistry. 42:10095-10103) disclosed an increase in the thermostability of TrCel6A, at an alkaline pH range, by replacing carboxyl-carboxylate pairs into amide-carboxylate pairs. A single mutant, E107Q, and a triple mutant, E107Q/D170N/D366N, have an improved T m above pH 7 but a lower T m at pH 5, which is the optimal pH of the wild-type TrCel6A. These mutations are found in, or close to, the N- and C-terminal loops. Hughes et al (Hughes, S. R., et al. 2006 . Proteome Sci. 4:10-23) disclose a directed evolution strategy to screen mutagenized clones of the Orpinomyces PC-2 cellulase F (OPC2Cel6F) with targeted variations in the last four codons for improved activity at lower pH, and identified two mutants having improved activity at lower pH and improved thermostability.
The above reports describing rational design of Family 6 cellulases suggest that the introduction of hydrogen or disulfide bonds into the C-terminal loops is not a good strategy to increase the thermostability at optimal hydrolysis conditions. Furthermore, stabilizing the exo-loop of the T. reesei Family 7 cellobiohydrolase Cel7A, which forms the roof of the active site tunnel, by introducing a disulfide bond with mutation D241C/D249C showed no improvement in thermostability (von Ossowski I., et al. 2003 . J. Mol. Biol. 333:817-829).
TrCel6A variants with improved thermostability are described in US Patent Publication No. 20060205042. Mutations were identified based alignment of TrCel6A amino acid sequence with those of eight Family 6 members using structural information and a modeling program. This alignment served as basis for the determination of a so-called consensus sequence. Those mutations that, according to the 3D-structure model of TrCel6A, fit into the structure without disturbance and were likely to improve the thermostability of the enzyme were selected as replacement for improved thermostability of TrCel6A. Among those identified as improving the thermostability of TrCel6A was the mutation of the serine at position 413 to a tyrosin (S413Y). This mutation increased the retention of enzymatic activity after a 1 hour pre-incubation at 61° C. from 20-23% for the parental TrCel6A to 39-43% for TrCel6A-S413Y; however, after a 1 hour pre-incubation at 65° C., the parent TrCel6A retained 5-9% of its activity while TrCel6A-S413Y retained 6-8% of its activity. The melting temperature, or Tm, improved by 0.2-0.3° C., from 66.5° C. for the parental TrCel6A to 66.7-66.8° C. for TrCel6A-S413Y.
Despite knowledge of the mechanisms of and desirable attributes for cellulases in the above and related industrial applications, the development of thermostable cellulases with improved stability, catalytic properties, or both improved stability and catalytic properties, would be advantageous. Although thermophilic and thermostable enzymes may be found in nature, the difficulty in achieving cost-effective large-scale production of these enzymes has limited their penetration into markets for industrial use. Therefore, a need exists for improved stable cellulases which can be economically produced at a high-level of expression by industrial micro-organisms such as T. reesei.
SUMMARY OF THE INVENTION
The present invention relates to modified Family 6 cellulases. More specifically, the invention relates to modified Family 6 cellulases that exhibit enhanced thermostability, alkalophilicity and/or thermophilicity. The present invention also relates to genetic constructs comprising nucleotide sequences encoding for modified Family 6 cellulases, methods for the production of the modified Family 6 cellulase from host strains and the use of the modified Family 6 cellulases in the hydrolysis of cellulose.
It is an object of the invention to provide an improved cellulase with increased thermostability, thermophilicity and alklophilicity.
This invention relates to a modified Family 6 cellulase produced by substitution of an amino acid at position 413 with a proline. The position(s) of the amino acid substitution(s) are determined from sequence alignment of the modified cellulase with a Trichoderma reesei Cel6A amino acid sequence as defined in SEQ ID NO: 1. The modified Family 6 cellulase exhibits enhanced thermostability, alkalophilicity, thermophilicity, or a combination thereof, relative to a parent Family 6 cellulase from which the Family 6 cellulase is derived.
The modified Family 6 cellulase may be derived from a filamentous fungus, such as Trichoderma reesei . In one embodiment of the invention, the modified cellulase is not derived from a cellulase which has a naturally-occurring proline residue at position 413 (TrCel6A numbering), for example a native Family 6 cellulase (CelF from Orpinomyces sp PC-2) which contains a proline residue at position 413.
This invention also includes a modified Family 6 cellulase comprising a proline residue at position 413 and further comprising polar amino acids at positions selected from 231, 305, 410 or a combination thereof.
The present invention also pertains to the modified Family 6 cellulase comprising a proline at position 413 and further comprising a substituted amino acid at position 231 selected from the group consisting of Ser, or Thr. The substituted amino acid at position 231 may be Ser.
The present invention also pertains to the modified Family 6 cellulase comprising a proline at position 413 and further comprising a substituted amino acid at position 305 selected from the group consisting of Ser and Thr.
The present invention also pertains to the modified Family 6 cellulase comprising a proline residue at position 413 and further comprising a substituted amino acid at position 410 selected from the group consisting of Gln and Asn.
The present invention also includes a Family 6 cellulase comprising a proline residue at position 413 and further comprising substituted amino acids at positions 231 and 305 with Ser residues (i.e. 231S, 305S), and substitution of an amino acid at position 410 with Gln. The modified Family 6 cellulase comprising these mutations may be from a filamentous fungus, such as Trichoderma reesei.
The present invention also relates to a modified Family 6 cellulase comprising a proline residue a position 413 and having an increase in thermostability relative to a parent cellulase, as measured by the “T 50 ”, from about 5° C. to about 30° C. higher, or from about 9° C. to about 20° C. higher than the corresponding parent cellulase.
The present invention also relates to a modified Family 6 cellulase comprising a proline residue at position 413 and having an increase in its temperature for maximal activity (T opt ) of from about 1.5° C. to about 30° C. higher, or from about or 2.5° C. to about 20° C. higher, that the T opt of a parent Family 6 celulase. The present invention also relates to a modified Family 6 cellulase comprising a proline residue at position 413 and having an increase in its pH for maximal activity (pH opt ) of about 0.5 units to about 6.0 units higher, relative to a parent cellulase.
The present invention also relates to a modified Family 6 cellulase selected from the group consisting of:
(SEQ ID NO: 12)
TrCe16A-S413P;
(SEQ ID NO: 13)
TrCe16A-G82E-G231S-N305S-R410Q-S413P;
(SEQ ID NO: 14)
TrCe16A-G231S-S413P;
(SEQ ID NO: 15)
TrCe16A-N305S-S413P;
(SEQ ID NO: 16)
TrCe16A-R410Q-S413P;
(SEQ ID NO: 17)
TrCe16A-G231S-N305S-S413P;
(SEQ ID NO: 18)
TrCe16A-G231S-R410Q-S413P;
(SEQ ID NO: 19)
TrCe16A-N305S-R410Q-S413P;
(SEQ ID NO: 20)
TrCe16A-G231S-N305S-R410Q-S413P;
(SEQ ID NO: 21)
HiCe16A-Y420P;
and
(SEQ ID NO: 22)
PcCe16A-S407P.
The invention also relates to genetic constructs for directing expression and secretion of the modified Family 6 cellulase from a host microbe including, but not limited to, strains of Trichoderma reesei.
The present invention relates to a genetic construct comprising a DNA sequence encoding a modified Family 6 cellulase comprising a proline residue at position 413, which DNA sequence is operably linked to DNA sequences regulating its expression and secretion from a host microbe. Preferably, the DNA sequences regulating the expression and secretion of the modified Family 6 cellulase are derived from the host microbe used for expression of the modified cellulase. The host microbe may be a yeast, such as Saccharomyces cerevisiae , or a filamentous fungus, such as Trichoderma reesei.
The invention also relates to a genetic construct comprising a DNA sequence encoding a modified Family 6 cellulase comprising a proline residue at position 413 and further comprising substituted amino acids at positions 231 and 305 with Ser and substitution of an amino acid at position 410 with Gln. The DNA sequence is operably linked to DNA sequences regulating its expression and secretion from a host microbe. Preferably, the DNA sequences regulating the expression and secretion of the modified Family 6 cellulase are derived from a filamentous fungus, including, but not limited to, Trichoderma reesei.
The invention also relates to a genetically modified microbe capable of expression and secretion of a modified Family 6 cellulase comprising a proline residue at position 413 and comprising a genetic construct encoding the modified Family 6 cellulase. In one embodiment, the modified Family 6 cellulase further comprises Ser residues at positions 231 and 305 and a Gln residue at position 410. Preferably, the genetically modified microbe is a yeast or filamentous fungus. The genetically modified microbe may be a species of Saccharomyces, Pichia, Hansenula, Trichoderma, Aspergillus, Fusarium, Humicola, Neurospora or Phanerochaete.
The present invention also relates to the use of a modified Family 6 cellulase comprising a proline residue at position 413 for treatment of a cellulosic substrate.
The invention also relates to the process of producing the modified Family 6 cellulase, including transformation of a yeast or fungal host, selection of recombinant yeast or fungal strains expressing the modified Family 6 cellulase, and culturing the selected recombinant strains in submerged liquid fermentations under conditions that induce the expression of the modified Family 6 cellulase.
Family 6 cellulases of the present invention comprising a proline residue at position 413 display improved thermostability and thermophilicity or alkalophilicity relative to wild-type Family 6 cellulases. Without wishing to be bound by theory, improved thermostability of the modified Family 6 cellulase results from amino acid substitutions that stabilize the C-terminal loop of Family 6 cellobiohydrolases by increasing the stability of the small α-helix.
Such cellulases find use in a variety of applications in industry that require enzyme stability and activities at temperatures and/or pH values above that of the native enzyme. For example, modified Family 6 cellulases, as described herein, may be used for the purposes of saccharification of lignocellulosic feedstocks for the production of fermentable sugars and fuel alcohol, improving the digestibility of feeds in ruminant and non-ruminant animals, pulp and paper processing, releasing dye from and softening denim.
This summary of the invention does not necessarily describe all features of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
These and other features of the invention will become more apparent from the following description in which reference is made to the appended drawings wherein:
FIG. 1 shows an amino acid sequence alignment among Family 6 cellulases. The amino acid numbering for each cellulase is compared with that of the Trichoderma reesei Cel6A (TrCel6A; SEQ ID NO:1) as indicated at the left and right of each sequences. The residues at positions 213, 305, 410 and 413 (relative to TrCel6A) are indicated with an asterisk. The residues identical with the corresponding amino acid in TrCel6A are in bold. For cellulases with a cellulose-binding domain, only the catalytic core sequences are presented. CfCel6B (SEQ ID NO:2); HiCel6A (SEQ ID NO:4); HiCel6B (SEQ ID NO:11); MtCel6A (SEQ ID NO:9); NpCel6A (SEQ ID NO:5); OpC2Cel6F (SEQ ID NO:6); PE2Cel6A (SEQ ID NO:8); TfCel6A (SEQ ID NO:10); TfCel6B (SEQ ID NO:3).
FIG. 2 depicts plasmid vectors a) YEp352/PGK91-1ΔNheI-xyl SS -cbh2 vector, b) YEpFLAGΔKpn10-cbh2 directing the expression and secretion of native and modified TrCel6A from recombinant Saccharomyces cerevisiae (The same organization if found for the TrCel6 variants cloned in the same vectors), c) YEpFLAGΔKpn10-PcCel6A directing the expression and secretion of native and modified PcCel6A from recombinant Saccharomyces cerevisiae (The same organization if found for the PcCel6 variants cloned in the same vectors), d) YEpFLAGΔKpn10-HiCel6A directing the expression and secretion of native and modified HiCel6A from recombinant Saccharomyces cerevisiae (The same organization if found for the HiCel6 variants cloned in the same vectors).
FIG. 3 depicts the vector pC/X—S413P-TV used to transform and direct the expression and secretion of modified TrCel6A from recombinant Trichoderma reesei . As shown, the TrCel6A-S413P gene is operable linked to the promoter of the cbh1 (TrCel7A) gene, the secretion signal peptide of the xln2 (TrXyl11B) genes and the transcriptional terminator of the native cbh2 (TrCel6A) gene. The selection marker is the Neurospora crassa pyr4 gene.
FIG. 4 shows the effect of pre-incubation temperature on the relative residual activity (%), as measured by the release of reducing sugars from β-glucan in a 30 minutes assay at a) 65° C., of the native TrCel6A and modified Family 6 cellulases TrCel6A-S413P, TrCel6A-R410Q-S413P, TrCel6A-G231 S-N305S-S413P, TrCel6A-G231S-R410Q-S413P, TrCel6A-N305S-R410Q-S413P and TrCel6A-G231S-N305S-R410Q-S413P, b) 60° C., of the native PcCel6A and modified Family 6 cellulases PcCel6A-S407P, c) 65° C., of the native HiCel6A and modified Family 6 cellulases HiCel6A-Y420P, after 15 minutes incubation at temperatures between 45° C. and 75° C.
FIG. 5 shows the effect of increasing pre-incubation times on the relative residual activity (%), as measured by the release of reducing sugars a soluble β-glucan substrate in a 30 minutes assay at a) 65° C., of the native TrCel6A and modified Family 6 cellulases TrCel6A-S413P, TrCel6A-R410Q-S413P, TrCel6A-G231S-N305S-S413P, TrCel6A-G231S-R410Q-S413P, TrCel6A-N305S-R410Q-S413P and TrCel6A-G2311S-N305S-R410Q-S413P after 0-120 minutes incubation at 60° C. and b) 60° C., of the native PcCel6A and modified Family 6 cellulases PcCel6A-S407P after 0-120 minutes incubation at 55° C.
FIG. 6 shows the effect of temperature on the enzymatic activity of a) the native TrCel6A and modified Family 6 cellulases TrCel6A-S413P, TrCel6A-G82E-G231S-N305S-R410Q-S413P, TrCel6A-R410Q-S413P, TrCel6A-G231S-N305S-S413P, TrCel6A-G231S-R410Q-S413P, TrCel6A-N305S-R410Q-S413P and TrCel6A-G231S-N305S-R410Q-S413P b) the native PcCel6A and modified Family 6 cellulases PcCel6A-S407P and c) the native HiCel6A and modified Family 6 cellulases HiCel6A-Y420P during 30 minutes incubation at pH 5.0. The data are normalized to the activity observed at the temperature optimum for each enzyme.
FIG. 7 shows the effect of pH on the enzymatic activity of a) the native TrCel6A and modified Family 6 cellulases TrCel6A-S413P, TrCel6A-G82E-G231S-N305S-R410Q-S413P, TrCel6A-R410Q-S413P, TrCel6A-G231S-N305S-S413P, TrCel6A-G231S-R410Q-S413P, TrCel6A-N305S-R410Q-S413P and TrCel6A-G231S-N305S-R410Q-S413P b) the native PcCel6A and modified Family 6 cellulases PcCel6A-S407P and c) the native HiCel6A and modified Family 6 cellulases HiCel6A-Y420P during 30 minutes incubation at pH 3.95-7.45. The data are normalized to the activity observed at the pH optimum for each enzyme.
FIG. 8 shows the relative activity of whole Trichoderma cellulases comprising TrCel6A or TrCel6A-S413P (along with all of the remaining native Trichoderma reesei cellulase components) in the enzymatic hydrolysis of pretreated lignocellulosic substrate after 0, 4, 20.5, 28, 40.5, 52, 68, 76 and 96 hours of pre-incubation in the absence of substrate at 50° C. in 50 mM citrate buffer, pH 5.0.
DESCRIPTION OF PREFERRED EMBODIMENT
The present invention relates to modified cellulase. More specifically, the invention relates to modified Family 6 cellulases with enhanced thermostability, alkalophilicity and/or thermophilicity. The present invention also relates to genetic constructs comprising nucleotide sequences encoding for modified Family 6 cellulases, methods for the production of the modified Family 6 cellulase from host strains and the use of the modified Family 6 cellulases in the hydrolysis of cellulose.
The following description is of a preferred embodiment by way of example only and without limitation to the combination of features necessary for carrying the invention into effect.
Modified Family 6 Cellulases
Family 6 (previously, Family B) cellulases enzymes are a group of enzymes that hydrolyse the β-1,4 glucosidic linkages in cellulose with inversion of configuration of the anomeric carbon (Claeyssens, M. and Henrissat, B. 1992, Protein Science 1: 1293-1297). Family 6 cellulases share extensive amino acid sequence similarity ( FIG. 1 ). A cellulase is classified as a Family 6 cellulase if it comprises amino acids common to other Family 6 cellulase, including two aspartic acid (D) residues which may serve as catalytic residues. These aspartic acid residues are found at positions 175 and 221 (see FIG. 1 ; based on TrCel6A ( Trichoderma reesei Cel6A enzyme) amino acid numbering). Most of the Family 6 cellulases identified thus far are mesophilic. However, this family also includes thermostable cellulases from Thermobifida fusca (TfCel6A and TfCel6B) and the alkalophilic cellulases from Humicola insolens (HiCel6A and HiCel6B).
The topology of Family 6 catalytic domains is a variant of the α/β-barrel with a central β-barrel containing seven parallel β-strands connected by five α-helices. One important difference between Family 6 cellobiohydrolases and endo-β-1,4-glucanases is the length of their N- and C-terminal loops present on each side of the active site and which are responsible for their functional behavior on cellulose. In the cellobiohydrolases, an extensive C-terminal loop forms a tunnel with the N-terminal loop enclosing the active site. This confers the unique property of cellobiohydrolases to attack the ends of crystalline cellulose where the N- and C-terminal loops maintain a single cellulose chain in the active site and facilitate the processive degradation of the substrate. In the endo-β-1,4-glucanases, the C-terminal loop is reduced in length and the N-terminal loop pulls it away from the active site and could be also shorter resulting in a more open active site allowing access to internal β-1,4 glycosidic bonds of cellulose for hydrolysis. The role of these loops in the functional behavior of Family 6 enzymes on cellulose was confirmed by the deletion of fifteen amino acids of the C-terminal loop of the Cellulomonas fimi cellobiohydrolase Cel6B in order to mimic the properties of an endo-β-1,4-glucanase (Meinke A., et al. 1995 . J. Biol. Chem. 270:4383-4386). The mutation enhanced the endo-β-1,4-glucanase activity of the enzyme on soluble cellulose, such as carboxymethylcellulose, and altered its cellobiohydrolase activity on insoluble cellulose.
Non-limiting examples of Family 6 cellulases that may be modified following the general approach and methodology as outlined herein are described in Table 1 below.
TABLE 1
Family 6 cellulase enzymes
Microbe
Cellulase
SEQ ID No.
Cellulomonia fimi
CfCe16B
2
Humicola insolens
HiCe16A
4
Humicola insolens
HiCe16B
11
Mycobacteriumn tuberculosis
MtCe16A
9
Neocallimatrix patriciarum
NpCe16A
5
Orpinomyces sp. PC-2
OpC2Ce16F
6
Phanerochaete chrysosporium
PcCe16A
7
Pyromyces sp. E2
PE2Ce16A
8
Thermobifida fusca
TfCe16A
10
Thermobifida fusca
TfCe16B
3
Examples of preferred Family 6 cellulases, which are not meant to be limiting, include Trichoderma reesei Cel6A, Humicola insolens Cel6A, Phanerochaete chrysosporium Cel6A, Cellulomonas fimi Cel6B, Thermobifida fusca Cel6B. More preferably, the modified cellulase of the present invention comprises a modified Trichoderma reesei Cel6A enzyme.
By “modified Family 6 cellulase” or “modified cellulase”, it is meant a Family 6 cellulase in which the amino acid at position 413 (said position determined from sequence alignment of said modified cellulase with a Trichoderma reesei Cel6A amino acid sequence as defined in SEQ ID NO:1) has been altered, using techniques that are known to one of skill in the art, to a proline and which exhibits improvements in thermostability, thermophilicity, alkalophilicity, or a combination thereof, over the corresponding unmodified Family 6 cellulase. Techniques for altering amino acid sequences include, but are not limited to, site-directed mutagenesis, cassette mutagenesis, random mutagenesis, synthetic oligonucleotide construction, cloning and other genetic engineering techniques (Eijsink V G, et al. 2005 . Biomol. Eng. 22:21-30, which is incorporated here in by reference). It will be understood that the modified cellulase may be derived from any Family 6 cellulase. The modified cellulase may be derived from a wild-type cellulase or from a cellulase that already contains other amino acid substitutions.
For the purposes of the present invention, the parent cellulase is a cellulase that does not contain a substitution of its original amino acid at position 413 (said position determined from sequence alignment of said modified cellulase with a Trichoderma reesei Cel6A amino acid sequence as defined in SEQ ID NO:1) by a proline and is otherwise identical to the modified cellulase. As such, the parent cellulase may be a cellulase that contains amino acid substitutions at other positions that have been introduced by genetic engineering or other techniques. However, a parent cellulase does not include those cellulases in which the naturally occurring amino acid at position 413 is a proline.
By “TrCel6A numbering”, it is meant the numbering corresponding to the position of amino acids based on the amino acid sequence of TrCel6A (Table 1; FIG. 1 ; SEQ ID NO:1). As disclosed below, and as is evident by FIG. 1 , Family 6 cellulases exhibit a substantial degree of sequence similarity. Therefore, by aligning the amino acids to optimize the sequence similarity between cellulase enzymes, and by using the amino acid numbering of TrCel6A as the basis for numbering, the positions of amino acids within other cellulase enzymes can be determined relative to TrCel6A.
Enzyme thermostability can be defined by its melting temperature (T m ), the half-life (t 1/2 ) at defined temperature, and the temperature at which 50% of the initial enzyme activity is lost after incubation at defined time (T 50 ). Thermophilic enzymes typically show common structural elements that have been identified as contributing factors to enzyme thermostability when compared to their mesophilic counterparts (e.g. see Sadeghi M., et al. 2006 . Biophys. Chem. 119:256-270). These structural elements include greater hydrophobicity, better packing, increased polar surface area, deletion or shortening of loops, interactions, smaller and less numerous cavities, stability of α-helix, increase in aromatic interactions, additional disulfide bridges or metal binding and glycosylation sites, decreased glycines and enhanced prolines content, increased hydrogen bonding and salt bridges, improved electrostatic interactions, decreased of thermolabile residues, and conformational strain release.
For the purposes of the present invention, a cellulase exhibits improved thermostability with respect to a corresponding parent cellulase if it has a T 50 which is at least about 4° C., or at least about 9° C. higher than that of the parent cellulase, or for example a cellulase having a T 50 from about 4° C. to about 30° C. higher, or any amount therebetween, or a T 50 from about 9° C. to about 30° C. higher, or any amount therebetween, when compared to that of the parent cellulase. The T 50 is the temperature at which the modified or the natural enzyme retains 50% of its residual activity after a pre-incubation for 15 minutes and is determined by the assay detailed in Example 10.4. As set forth in Example 10.4, the residual activity against β-glucan in a 30 minute assay at 65° C. is normalized to 100%.
The modified Family 6 cellulase may have Tso which is about 4° C. to about 30° C. higher than that of a corresponding parent cellulase, or any range therebetween, about 5° C. to about 20° C. higher, or any range therebetween, about 8° C. to about 15° C. higher, or any range therebetween, or from about 9° C. to about 15° C. higher, or any range therebetween. For example, the modified cellulase may have a T 50 that is at least about 4, 5, 6, 7, 8, 9, 10, 12, 14, 16, 18, 20, 22, 24, 26, 28, or 30° C. higher than that of the corresponding parent cellulase.
The modified Family 6 cellulase may also be characterized as having a T 50 above 65° C. (or at least 5° C. above that of the corresponding parent Family 6 cellulase), for example, the modified cellulase may have a T 50 from about 65° C. to about 90° C., or any amount therebetween. The modified Family 6 cellulase may have a T 50 above 70° C. (or at least 9° C. above the parent Family 6 cellulase) for example, the modified cellulase may have a T 50 so from about 70° C. to about 90° C., or any amount therebetween. The Family 6 cellulase may have a T 50 of 50, 55, 60, 65, 70, 75, 80, 85 or 90° C. or any amount therebetween.
For the purposes of this specification, a cellulase exhibits improved thermophilicity with respect to a corresponding parent cellulase if the cellulase exhibits a temperature optimum (T opt ) that is at least about 1.5° C. higher than the T opt of the corresponding parent cellulase. For example, a cellulase exhibits improved thermophilicity if the cellulase exhibits a temperature optimum (T opt ) that is from about 1.5° C. to about 30° C. or any amount therebetween, higher than the T opt of the corresponding parent cellulase By temperature optimum or T opt , it is meant the highest temperature at which a cellulase exhibits its maximal activity. For the purposes of this specification, the T opt of a Family 6 cellulase is determined by measuring the temperature profile of activity against a β-glucan substrate as detailed in Example 10.1. The temperature profile for the activity of the cellulase is measured at its pH optimum.
The modified Family 6 cellulase may have a T opt which is at least about 1.5° C. to about 30° C. higher than the T opt of a corresponding parent Family 6 cellulase. In a preferred embodiment, the T opt of the modified Family 6 cellulase is at least about 2.5° C. to about 20° C. higher than the T opt of parent Family 6 cellulase. For example, the modified Family 6 cellulase may have a T opt of at least about 1.5, 2.5, 4.0, 5.0, 6.0, 8.0, 10.0, 12.0, 15.0, 20.0, 25.0, or 30° C. higher than that of the corresponding parent cellulase.
The terms “thermostability” and “thermophilicity” have been used interchangeably within the literature. However, the use of the terms as defined herein is consistent with the usage of the terms in the art (Mathrani, I and Ahring, B. K. 1992 Appl. Microbiol. Biotechnol. 38:23-27).
For the purposes of the present invention, a cellulase exhibits improved alkalophilicity with respect to a corresponding parent cellulase if the cellulase exhibits a pH opt that is at least about 0.5 units higher than the pH opt of the parent cellulase. By pH opt , it is meant the highest pH at which a cellulase exhibits its maximal activity. For the purpose of this specification, the pH opt is determined by measuring the pH profile of a Family 6 cellulase as set out in Example 10.2.
The modified Family 6 cellulase may have a pH opt that is at least about 0.5 units to about 6.0 units, or any amount therebetween, higher than the pH opt of the parent Family 6 cellulase. In a preferred embodiment, the pH opt , of the modified Family 6 cellulase is at least about 0.8 units to about 5.0 units, or any amount therebetween, higher than the pH opt parent Family 6 cellulase. For example, the pH opt of the cellulase may be about 0.5, 1.0, 1.5, 2.0, 2.5, 3.0, 3.5, 4.0, 4.5, 5.0, 5.5 or 6.0 units higher than the pH opt of the parent cellulase.
As described in more detail herein, several mutant Family 6 cellulases have been prepared that exhibit enhanced thermostability, thermophilicity, alkalophilicity, or a combination thereof. A list of several mutants, which is not to be considered limiting in any manner, is presented in Table 2.
TABLE 2 Modified Family 6 cellulases New mutant TrCe16A SEQ ID NO: TrCe16A-S413P 12 TrCe16A-G82E-G231S-N305S-R410Q-S413P 13 TrCe16A-G231S-S413P 14 TrCe16A-N305S-S413P 15 TrCe16A-R410Q-S413P 16 TrCe16A-G231S-N305S-S413P 17 TrCe16A-G231S-R410Q-S413P 18 TrCe16A-N305S-R410Q-S413P 19 TrCe16A-G231S-N305S-R410Q-S413P 20 HiCe16A-Y420P 21 PcCe16A-S407P 22
Genetic Constructs Comprising Modified Family 6 cellulases
The present invention also relates to genetic constructs comprising a DNA sequence encoding the modified Family 6 cellulase operably linked to regulatory DNA sequences directing the expression and secretion of the modified Family 6 cellulase from a host microbe. The regulatory sequences are preferably functional in a fungal host. The regulatory sequences may be derived from genes that are highly expressed and secreted in the host microbe under industrial fermentation conditions. In a preferred embodiment, the regulatory sequences are derived from any one or more of the Trichoderma reesei cellulase or hemicellulase genes.
The genetic construct may further comprise a selectable marker to enable isolation of a genetically modified microbe transformed with the construct as is commonly known with the art. The selectable marker may confer resistance to an antibiotic or the ability to grow on medium lacking a specific nutrient to the host organism that otherwise could not grow under these conditions. The present invention is not limited by the choice of selection marker, and one of skill may readily determine an appropriate marker. In a preferred embodiment, the selection marker confers resistance to hygromycin, phleomycin, kanamycin, geneticin, or G418, complements a deficiency of the host microbe in one of the trp, arg, leu, pyr4, pyr2, ura3, ura5, his, or ade genes or confers the ability to grow on acetamide as a sole nitrogen source. In a more preferred embodiment, the selectable marker is the Neurospora crassa pyr4 gene encoding orotidine-5′-decarboxylase.
Genetically Modified Microbes Comprising Modified Family 6 cellulases
The modified Family 6 cellulase may be expressed and secreted from a genetically modified microbe produced by transformation of a host microbe with a genetic construct encoding the modified Family 6 cellulase. The host microbe is preferably a yeast or a filamentous fungi, including, but not limited to, a species of Saccharomyces, Pichia, Hansenula, Trichoderma, Hypocrea, Aspergillus, Fusarium, Humicola, Neurospora or Phanerochaete . Typically, the host microbe is one from which the gene(s) encoding any or all Family 6 cellulases have been deleted. In a most preferred embodiment, the host microbe is an industrial strain of Trichoderma reesei.
The genetic construct may be introduced into the host microbe by any number of methods known by one skilled in the art of microbial transformation, including but not limited to, treatment of cells with CaCl 2 , electroporation, biolistic bombardment, PEG-mediated fusion of protoplasts (e.g. White et al., WO 2005/093072, which is incorporated herein by reference).
After selecting the recombinant fungal strains expressing the modified Family 6 cellulase, the selected recombinant strains may be cultured in submerged liquid fermentations under conditions that induce the expression of the modified Family 6 cellulase.
Hydrolysis of Cellulosic Substrates
The present invention also relates to the use of the modified Family 6 cellulases described herein for the hydrolysis of a cellulosic substrate. By the term “cellulosic substrate”, it is meant any substrate derived from plant biomass and comprising cellulose, including, but not limited to, lignocellulosic feedstocks for the production of ethanol or other high value products, animal feeds, forestry waste products, such as pulp and wood chips, and textiles.
By the term “lignocellulosic feedstock”, it is meant any type of plant biomass such as, but not limited to, non-woody plant biomass, cultivated crops such as, but not limited to, grasses, for example, but not limited to, C4 grasses, such as switch grass, cord grass, rye grass, miscanthus, reed canary grass, or a combination thereof, sugar processing residues, for example, but not limited to, baggase, beet pulp, or a combination thereof, agricultural residues, for example, but not limited to, soybean stover, corn stover, rice straw, rice hulls, barley straw, corn cobs, wheat straw, canola straw, oat straw, oat hulls, corn fiber, or a combination thereof, forestry biomass for example, but not limited to, recycled wood pulp fiber, sawdust, hardwood, for example aspen wood, softwood, or a combination thereof.
In the saccharification of lignocellulosic feedstocks for the production of ethanol, or other products, cellulases of the invention may be used to hydrolyze a pretreated feedstock produced by, for example, but not limited to, steam explosion (see Foody, U.S. Pat. No. 4,461,648, which is incorporated herein by reference and to which the reader is directed for reference). Pretreatment may involve treatment of the feedstock with steam, acid, or typically a combination of steam and acid, such that the cellulose surface area is greatly increased as the fibrous feedstock is converted to a muddy texture, with little conversion of the cellulose to glucose. The cellulase enzymes of the invention then may be used to hydrolyze cellulose to glucose in a subsequent step. The glucose may then be converted to ethanol or other products.
Modified cellulase enzymes of the invention may be added to pulp or wood chips to enhance the bleaching or reduce refining energy of the pulp. The pulp may be produced by a chemical pulping process or by mechanical refining.
Increasing the Thermostability of Family 6 Cellulases
The thermostability of the mutant Family 6 cellulase was compared via pre-incubation of the enzyme in the absence of substrate at different temperatures. After 15 minutes, the residual activity of the cellulase was determined via a standard assay with soluble β-glucan as a substrate.
The effect of the S413P mutation, alone or in combination with one or more of G231S, N305S and R410Q, on the thermostability of Family 6 cellulase was determined via a comparative study of the modified TrCel6A-S413P and the parent TrCel6A. After pre-incubation at higher temperatures for up to 120 minutes, the former retained greater residual activity than the latter ( FIG. 5 a ).
The pre-incubation temperature that allowed Family 6 cellulase to retain 50% of the residual activity, T 50 , was determined. For the modified Family 6 cellulase, TrCel6A-S413P, the T 50 was 64.1° C., as compared to 59° C. for the parent TrCel6A ( FIG. 4 a ). This represented an increase in the thermostability by over 5° C. through the introduction of the S413P mutation.
The T 50 of the other TrCel6A variants was at least 3.2° C. higher then wild-type TrCel6A. PcCel6A-S407P and Hicel6A-Y420P also have shown an increase in T 50 when compared to their respective parent enzyme ( FIGS. 4 b and c ).
Increasing the Thermophilicity of Family 6 Cellulases
The thermophilicity of the modified Family 6 cellulases was determined by measuring effect of the assay temperature on the hydrolysis of β-glucan.
All modified Family 6 cellulases shown an improved T opt for β-glucan hydrolysis when compared to their respective wild-type except variant TrCel6A-G231S-N305S-R410Q-S413P which on the other hand exhibits a broad temperature range with more then 80% of the maximum activity ( FIG. 6 ). Among all TrCel6A variants, TrCel6A-S413P has the higher optimal temperature at 72.2° C., an increase of 5.6° C. in thermophilicity compared to wild-type TrCel6A ( FIG. 6 a ). PcCel6A-S407P and HiCel6A-Y420P also exhibit an increase in optimal temperature when compared to their respective wild-type ( FIGS. 6 b and c ).
Increasing the Alkalophilicity of Family 6 Cellulases
The effect of the S413P mutation, alone or in combination with one or more of G231S, N305S and R410Q, on the pH/activity profile of Family 6 cellulase was also studied.
All modified Family 6 cellulases exhibit increased alkalophilicity when compared to their wild-type. For TrCel6A, the most important shift was observed with variants TrCel6A-G231S-R410Q-S413P (+1.25 pH units) followed by TrCel6A-G231S-N305S-R410Q-S413P (+1.01 pH units).
Cellulase systems comprising modified Family 6 cellulases in combination with non-Family 6 cellulases show improved thermostability. A Trichoderma cellulase system comprising TrCel6A-S413P maintains at least 80% of its maximal activity after incubation in the absence of substrate at 50° C. for 96 hours, while the corresponding cellulase system comprising the parent TrCel6A maintains only 50% of its maximal activity ( FIG. 8 ).
In summary, improved thermostable, alkalophilic and/or thermophlic mutant Family 6 cellulase of the invention comprise a proline residue at position 413 and may further comprise one or more than one of the following amino acid substitutions:
(i) a substituted amino acid at position 231 such as a polar amino acid, including, but not limited to, Ser; (ii) a substituted amino acid at position 305, such as a polar amino acid, including, but not limited to, Ser; (iii) a substituted amino acid at position 410, such as a polar amino acid, including, but not limited to, Gln; and (iv) combinations of any of the above mutations set out in (i) to (iii).
Non-limiting examples of preferred Family 6 cellulase mutants comprising a S413P in combination with the amino acid substitutions listed above are given in Table 2.
Furthermore, the modified Family 6 cellulase of the present invention may comprise amino acid substitutions not listed above in combination with S413P.
The above description is not intended to limit the claimed invention in any manner. Furthermore, the discussed combination of features might not be absolutely necessary for the inventive solution.
EXAMPLES
The present invention will be further illustrated in the following examples. However, it is to be understood that these examples are for illustrative purposes only and should not be used to limit the scope of the present invention in any manner.
Examples
Example 1 describes the strains and vectors used in the following examples. Examples 2-5 describe the random mutagenesis of the TrCel6A gene, cloning of the random mutagenesis libraries in yeast vectors and high-throughput screening to identify modified Family 6 cellulases with increased thermostability. Examples 6-8 describe the cloning, recombination and expression of the modified and native Family 6 cellulase genes in an alternative yeast vector for higher expression. Example 9 describes the enzymatic characterization of modified Family 6 cellulases. Example 10 describes genetic constructs to express and secrete the modified Family 6 cellulases in a filamentous fungus. Example 11 describes the transformation of fungal protoplasts with genetic constructs expressing modified Family 6 cellulases. Example 12 describes the production of modified Family 6 cellulases from modified microbes in submerged liquid cultures. Example 13 describes the characterization of whole Trichoderma cellulases comprising modified Family 6 cellulases in combination with cellulases from other Families.
Example 1
Strains and Vectors
Saccharomyces cerevisiae strain DBY747 (his3-Δ1 leu2-3 leu2-112 ura3-52 trp1-289 (amber mutation) gal(s) CUP(r)) was obtained from the ATCC. S. cerevisiae strain BJ3505 (pep4::HIS3 prb-Δ10.6R HIS3 lys2-208 trp1-Δ101 ura3-52 gal2 can1) was obtained from Sigma and was a part of the Amino-Terminal Yeast FLAG Expression Kit.
A strain of Trichoderma reesei obtained derived from RutC30 (ATCC #56765; Montenecourt, B. and Eveleigh D. 1979 . Adv. Chem. Ser. 181: 289-301) comprising a disrupted native TrCel6A gene was used in the experiments described herein.
Escherichia coli strains HB101 (F − thi-1 hsdS20 (r B − , m B − ) supE44 recA13 ara-14 leuB6 proA2 lacY1 galK2 rpsL20 (str I ) xyl-5 mtl-1) and DH5α (F − φ80lacZΔM15 Δ(lacZYA-argF)U169 recA1 endA1 hsdR17 (r k − , m k + ) phoA supE44 thi-1 gyrA96 relA1 λ − ) were obtained from Invitrogen.
Humicola insolens and Phanerochaete chrysosporium strains were obtained from ATCC® (#22082™ and #201542™ respectively).
The YEp352/PGK91-1 vector was obtained from the National Institute of Health. The YEpFLAG-1 vector was obtained from Sigma as a part of the Amino-Terminal Yeast FLAG Expression Kit. The pALTER®-1 vector was obtained from Promega as a part of the Altered Site® II in vitro mutagenesis System. The pBluescript® II KS-vector was obtained from Stratagene.
Example 2
Cloning of the TrCel6A gene into the YEp352/PGK91-1 and Transformation in Yeast
2.1 Isolation of total RNA from T. reesei and Generation of Total cDNA.
T. reesei biomass was grown under inducing conditions as described in example 13 then 50 mg of biomass was used to isolate total RNA with the Absolutely RNA® Miniprep Kit (Stratagene) according to the manufacturer procedure. Total cDNA was generated from the total RNA using the SuperScript™II Reverse Transcriptase (Invitrogen) according to the manufacturer procedure.
2.2 Cloning and Transformation in Yeast.
In order to facilitate cloning using NheI and KpnI restriction enzymes, the unique NheI site at position 1936 of the YEp352/PGK91-1 vector was blunted using the DNA Polymerase I large (Klenow) fragment to generate YEp352/PGK91-1ΔNheI.
The cbh2 gene encoding TrCel6A was amplified by PCR from total cDNA (generated as described in example 2.1) using primers (C2STU 5 and C2STU3 that introduce StuI-NheI sites upstream and a KpnI-BglII-StuI sites downstream to the coding sequence. In parallel, the secretion signal peptide of the TrXyl11B gene was amplified by PCR from a genomic clone of TrXyl11B (pXYN2K2, example 11.3) using primers to introduce BglII at the 5′ end and an NheI site at 3′ end of the amplicon, which was subsequently cloned using these restriction sites into pBluescript® II KS-(Stratagene) to generate the plasmid pXYNSS-Nhe. The amplicon was then cloned into the unique NheI and Bgl II sites of pXYNSS-Nhe. A fragment comprising the TrCel6A gene operably linked to the secretion signal peptide of TrXyl11B with BglII sites at the 5′ and 3′ ends was subsequently amplified by PCR from this intermediate construction using primers (BGL2XYF and C2STU3). This amplicon was cloned in the BglII site of the YEp352/PGK91-1ΔNheI vector to yield to the YEp352/PGK91-1ΔNheI-xyl SS -cbh2 vector ( FIG. 2 a ) and transformed in yeast strain DBY747 using the procedure described by Gietz, R. D. and Woods, R. A. (Gietz, R. D. and Woods, R. A. 2002 . Meth. Enzym. 350: 87-96) and plated on SC-Ura plate. Primer sequences are listed below:
StuI NheI C2STU5: 5′GAT AGG CCT GCT AGC TGC TCA AGC GTC TGG GGC (SEQ ID NO: 24) StuI BglII KpnI C2STU3: 5′ATC AGG CCT AGA TCT GGT ACC TTA CAG GAA CGA TGG (SEQ ID NO: 25) BglII BGL2XYF: 5′GAT C AG ATC T AT GGT CTC CTT CAC CTC CCT C (SEQ ID NO: 26)
SC-Ura pate contains:
Component
g/L
Yeast Nitrogen Base without amino
1.7
acid and ammonium sulfalte (BD)
(NH 4 ) 2 SO 4 (Sigma)
5.0
Complete Supplement Media without uridine (Clontech)
0.77
Agar (BD)
17.0
Glucose (Fisher)
20.0
pH 5.6
Example 3
Making Error Prone-PCR Libraries of cbh2
Random mutagenesis libraries were generated using two methods: a Mn 2+ /dITP method and a biased nucleotides method. For the Mn 2+ /dITP method, the TrCel6A gene was amplified from YEp352/PGK91-1ΔNheI-xyl SS -cbh2 vector using the above-mentioned C2STU3 and BGL2XYF primers in a two step PCR method. In the first step, the amplification occurs for 20 cycles in the presence 20 μM MnCl 2 . The second step is done with the same primers but using the product from the first step as template and with 0, 25, 50, 75 or 100 μM dITP (0 μM being a control). For the biased nucleotides method, the PCR is conducted with 1:3, 1:5 or 1:10 molar ratio between purine bases and pyrimidine bases respectively.
To get mostly mutations in the core of the enzyme, the final amplicon in both cases was cloned using the XhoI and KpnI restriction sites in the YEp352/PGK91-1ΔNheI-xyl SS -cbh2 vector (XhoI cuts right after sequence coding for S55's codon in the linker of the enzyme) and transformed in S. cerevisiae strain DBY747.
Example 4
Making Site-Directed Semi-Random Libraries of TrCel6A
Glycine residues have no β-carbon and thus have considerably greater backbone conformational freedom. By analyzing the three-dimensional structure of TrCel6A, 4 glycines residues were targeted to decrease this degree of freedom, namely G90, G85, G231 and G384. All but G231 positions were saturated and G231 was randomly mutated for an alanine, a proline, a serine or a threonine by megaprimer PCR using the following primers:
G 90 to Xxx:
(SEQ ID NO:27)
5′ CCA ACA AAA GGG TTN NNT GAA TAC GTA GCG G
G 85 to Xxx:
(SEQ ID NO:28)
5′ CCC AAG GAG TGA CNN NAA CAA AAG GGT TG
G 231 to A/P/S/T:
(SEQ ID NO:29)
5′ GGT GAC CAA CCT CNC NAC TCC AAA GTG TG
G 384 to Xxx:
(SEQ ID NO:30)
5′ CCG CAA ACA CTN NNG ACT CGT TGC TG
All amplicons were cloned in the YEp352/PGK91-1ΔNheI-xyl SS -cbh2 vector as described in example 3.
Example 5
Screening of TrCel6A Gene Libraries for Modified Family 6 Cellulases with Increased Thermostability
A total of 3371 TrCel6A variants generated as per Example 3 and 4 were screened as follows: each yeast colony was cultured in a well of a 96-deep well plate containing 1 mL of YPD (1% yeast extract, 2% peptone, 2% glucose) media and one 1.5 mm glass bead for 2 days in a Vortemp apparatus (Labnet) at 650 rpm and at 30° C. The plate was centrifuged at 3,000×g for 5 minutes then 300 μL of supernatant was filtered through each of two Biodyne B positively charged nylon membranes (Pall Gelman) using a Bio-Dot apparatus (Bio-Rad).
Membranes were placed on a moist (not wet) Whatman paper containing 50 mM sodium citrate at pH 4.8. One was incubated for 12 minutes at 62° C. and the other one at room temperature (control). Membranes were then placed on agar plates containing β-glucan substrate and incubated overnight at 50° C. in a humidity chamber:
Component
g/L
(NH 4 ) 2 SO 4 (Sigma)
5.0
β-glucan (Barley, Medium Viscosity; Megazyme)
2.0
Agar (BD)
17.0
Glucose (Fisher)
20.0
pH 5.6
Agar plates were then stained 30-60 minutes by covering them with a 0.1% (w/v) Congo Red solution then rinsed 2-3 times with demineralized water to remove unbound dye and covered with 1M NaCl for 10-15 min. The clearing zones could be observed and compared between the control and the plate that was covered with the heat treated membrane. Each plate was scrutinized by at least two people and every positive variant that appeared to maintain its activity after the 12 min incubation at 62° C. when compared to the wild-type TrCel6A control was considered as potential positive. Each potential positive clone was produced again in microculture to allow observation of the phenotype on an additional occasion and to reduce the possibility of false negative.
From that screening, five positive clones were sequenced to identify the mutations they carry. Clone E6 contained a S413P mutation, clones G3 and F7 both contained a G231S mutation, clone A3 contained a N305S mutation and clone 7 contained a R410Q mutation as well as a G82E mutation at the end of the linker peptide.
Example 6
Cloning Modified TrCel6A Genes into the YEpFLAG-1 Vector for Higher Expression from Saccharomyces cerevisiae
In order to facilitate cloning of the modified TrCel6A genes identified in Example 5 into the YEpPLAG-1 vector in such a way as to operabling link the genes to the αmating factor secretion signal peptide, two modifications were necessary. First, the unique KpnI site present in the α secretion signal peptide sequence (bp 1457) of the YEpFLAG-1 vector was removed. This was done by PCR using two complementary mutagenic primers (5′-FLAGΔKpnI and 3′-FLAGΔKpnI). The mutagenesis reaction was then digested with DpnI for 1 hour at 37° C. and the plasmid was allowed to recircularize by placing the tube in boiling water and allowed to cool slowly to room temperature. This reaction was transformed directly in E. coli DH5α chemically competent cells. A clone that was digested only once with KpnI was sequenced to confirm the desired mutation and was used for further work and named YEpFLAGΔKpn. Primer sequences are listed below:
ΔKpnI
5′-FLAGΔKpnI:
5′CTA AAG AAG AAG G GG TAC A TT TGG ATA AAA GAG AC
(SEQ ID NO:31)
66 KpnI
3′-FLAGΔKpnI:
5′GTC TCT TTT ATC CAA A TG TAC C CC TTC TTC TTT AG
(SEQ ID NO:32)
Second, the T. reesei cbh1 gene was amplified from pCOR132 (Example 11.2) by PCR using primers to introduce XhoI-NheI sites at the 5′ end and Kpn1-Apa1 sites at 3′ end of the amplified fragment. This fragment was then inserted as an XhoI/ApaI fragments into the XhoI/ApaI linearized YEpFLAG-1 expression vector. The resulting vector, YEpFLAGΔKpn10, allows insertion of the modified TrCel6A genes identified in Example 5 as NheI/KpnI fragments in such a way that the coding regions are operably linked to the α secretion signal peptide.
The YEp352/PGK91-1ΔNheI-xyl SS -cbh2 vectors containing native or modified TrCel6A genes were isolated from transformants of yeast strain DBY747 using method modified from Hoffman and Winston (Hoffman, C. S., and Winston, F. 1987 . Gene 57: 267-272) and transformed in E. coli HB101 chemically competent cells. The modified TrCel6A genes were removed from the YEp352/PGK91-1ΔNheI-xyl SS -cbh2 vectors by digestion with NheI and KpnI and cloned in the YEpFLAGΔKpn10 using the same restriction enzymes. The final constructs, YEpFLAGΔKpn10-cbh2, YEpFLAGΔKpn10-G82E-R410Q, YEpFLAGΔKpn10-N305S YEpFLAGΔKpn10-S413P and YEpFLAGΔKpn10-G231S ( FIG. 2 b ), were transformed into yeast strain BJ3505 using the procedure described by Gietz and Woods (Gietz R. D. and Woods R. A. 2002 . Meth. Enzym. 350: 87-96) and plated on SC-trp plate. The integrity of the cloned region of all variants was confirmed by DNA sequence analysis. The amino acid sequence of the parent TrCel6A produced by this yeast vector (SEQ ID NO. 23) shows the C-terminal extension containing the FLAG peptide. However, it was determined experimentally that this small peptide extension does not in any way contribute to the thermostability, thermophilicity or alkalophilicity of the parent or modified TrCel6A cellulases.
SC-trp Pate Contains:
Component
g/L
Yeast Nitrogen Base without amino acid and ammonium
1.7
sulfalte (BD)
(NH 4 ) 2 SO 4 (Sigma)
5.0
Yeast Synthetic Drop-Out Media Supplement without
1
Tryptophan (Sigma)
Agar (BD)
20
Glucose (Fisher)
20
Example 7
Generation of Other TrCel6A Variants, PcCel6A, PcCel6A-S407P, HiCel6A and HiCel6A-Y420P and Their Cloning in the YEpFLAG-1 Vector
7.1 Generation of Other TrCel6A Variants.
TrCel6A variant R410Q-S413P was obtained by error-prone PCR on the TrCel6A-S413P variant while cloned in the YEp352/PGK91-1ΔNheI using the Mutazyme® II DNA polymerase (Stratagene). It was then amplified from that source using primers 5′FLAG-Cel6A-GR and 3′FLAG-Cel6A-GR that introduce sequences homologue to the YEpFLAG-1 vector upstream the NheI site and downstream the ApaI site respectively.
Mutagenic primers in conjunction with primer 3′FLAG-Cel6A-GR were used to generate megaprimer PCR of the following TrCel6A mutation combinations: G231S-S413P, N305S-S413P, G231S-N305S-S413P, G231S-R410Q-S413P, N305S-R410Q-S413P and G231S-N305S-R410Q-S413P. The resulting PCR products were isolated and used as a reverse primer in conjunction with the forward primer 5′FLAG-Cel6A-GR to generate final constructs. Primers sequences are listed below:
5′G231SCBH2 (SEQ ID NO: 35) 5′GGT GAC CAA CCT CTC TAC TCC AAA GTG TG 5′N305SGBH2 (SEQ ID NO: 36) 5′CAA TGT CGC CAG CTA CAA CGG G 5′Ce16A-E82G (SEQ ID NO: 38) 5′GTA CCT CCA GTC GGA TCG GGA ACC GCT 5′FLAG-Ce16A-GR (SEQ ID NO:39) 5′AGA GAC TAC AAG GAT GAC GAT GAC AAG GAA TTC CTC GAG GCT AGC TGC TCA AGC G 3′FLAG-Ce16A-GR (SEQ ID NO: 40) 5′GAC CCA TCA GCG GCC GCT TAC CGC GGG TCG ACG GGC CCG GTA CCT TAC AGG AAC G
7.2 Generation PcCel6A and PcCel6A-S407P.
Lyophilized P. chrysosporium was resuspended in 300 μL sterile H 2 O and 50 μL were spreaded onto PDA plates. Plates were incubated at 24° C. for 4 days. Spores for P. chrysosporium were inoculated on a cellophane circle on top of a PDA plate and biomass was harvested after 4-6 days at 24° C. Then, 50 mg of biomass was used to isolate total RNA with the Absolutely RNA® Miniprep Kit (Stratagene) according to the manufacturer procedure. Total cDNA was generated from the total RNA using the SuperScript™II Reverse Transcriptase (Invitrogen) according to the manufacturer procedure. Gene encoding for PcCel6A was amplified from the cDNA using the following primers:
5′PcCe16A-cDNA
(SEQ ID NO: 41)
5′CTA TTG CTA GCT CGG AGT GGG GAC AGT GCG GTG GC
3′PcCe16A-cDNA
(SEQ ID NO: 42)
5′CTA TTG AAT TCG GTA CCC TAC AGC GGC GGG TTG GCA
GCA GAA AC
PCR amplicon was clone in the pGEM®-T Easy vector by TA-cloning following manufacturer's recommendations. The gene encoding for PcCel6A was then amplified from that source using primers 5′FLAG-PcCel6A-GR and 3′FLAG-PcCel6A-GR that introduce sequences homologue to the YEpFLAG-1 vector upstream the NheI site and downstream the SstII site respectively.
Mutagenic primer 5′PcCel6A-S407P in conjunction with primer 3′FLAG-PcCel6A-GR was used to generate megaprimer PCR. The resulting PCR product was isolated and used as a reverse primer in conjunction with the forward primer 5′FLAG-PcCel6A-GR to generate final construct. Primers sequences are listed below:
5′FLAG-PcCe16A-GR (SEQ ID NO: 43) 5′AAGGATGACGATGACAAGGAATTCCTCGAGGCTAGCTCGGAGTG GGG ACAGTGC 3′FLAG-PcCe16A-GR (SEQ ID NO: 44) 5′TGGGACGCTCGACGGATCAGCGGCCGCTTACCGCGGCTACAGCG GCG GGTTGGC 5′PcCe16A-S407P (SEQ ID NO: 45) 5′CCCCGCTACGACCCTACTTGTTCTCTG
7.3 Generation HiCel6A and HiCel6A-Y420P.
Lyophilized H. insolens was resuspended in 300 μL sterile H 2 O and 50 μL was spreaded onto Emerson YPSS pH 7 agar plate (0.4% Yeast extract, 0.1% K 2 HPO 4 , 0.05% MgSO 4 .7H 2 O, 1.5% Glucose, 1.5% Agar). Fungus was incubated for 6 days at 45° C. then spores were inoculated in Novo media (as per Barbesgaard U.S. Pat. No. 4,435,307): Incubation for 48 hours at 37° C. in 100 mL growth phase media (2.4% CSL, 2.4% Glucose, 0.5% Soy oil, pH adjusted to 5.5, 0.5% CaCO 3 ), then 6 mL of pre-culture was transferred into 100 mL production phase media (0.25% NH 4 NO 3 , 0.56% KH 2 PO 4 , 0.44% K 2 HPO 4 , 0.075% MgSO 4 .7H 2 O, 2% Sigmacell, pH adjusted to 7, 0.25% CaCO 3 ) and culture was incubated for up to 4 days prior to biomass harvest. Then, 50 mg of biomass was used to isolate total RNA with the Absolutely RNA® Miniprep Kit (Stratagene) according to the manufacturer procedure. Total cDNA was generated from the total RNA using the SuperScript™II Reverse Transcriptase (Invitrogen) according to the manufacturer procedure. Gene encoding for HiCel6A was amplified from the cDNA using the following primers:
5′HiCe16A-cDNA
(SEQ ID NO: 46)
5′CTA TTG CTA GCT GTG CCC CGA CTT GGG GCC AGT GC
3′HiCe16A-cDNA
(SEQ ID NO: 47)
5′CTA TTG AAT TCG GTA CCT CAG AAC GGC GGA TTG GCA
TTA CGA AG
PCR Amplicon was Clone in the pGEMO-T Easy vector by TA-Cloning following manufacturer's recommendations. The gene encoding for HiCel6A was then amplified from that source using primers 5′FLAG-HiCel6A-GR and 3′FLAG-HiCel6A-GR that introduce sequences homologue to the YEpFLAG-1 vector upstream the NheI site and downstream the ApaI site respectively.
Mutagenic primer 5′HiCel6A-Y420P in conjunction with primer 3′FLAG-HiCel6A-GR was used to generate megaprimer PCR. The resulting PCR product was isolated and used as a reverse primer in conjunction with the forward primer 5′FLAG-HiCel6A-GR to generate final construct. Primers sequences are listed below:
5′FLAG-HiCe16A-GR (SEQ ID NO: 48) 5′AAGGATGACGATGACAAGGAATTCCTCGAGGCTAGCTGTGCCCC GACTTGGGGC 3′FLAG-HiCe16A-GR (SEQ ID NO: 49) 5′AGCGGCCGCTTACCGCGGGTCGACGGGCCCGGTACCTCAGAACGG CGGATTGGC 5′HiCe16A-Y420P (SEQ ID NO: 50) 5′GCCCGCTACGACCCTCACTGCGGTCTC
7.4 Cloning of the Other TrCel6A Variants, PcCel6A, PcCel6A-S407P, HiCel6A and HiCel6A-Y420P in YEpFLAG-1 and Transformation in BJ3505.
The YEpFLAGΔKpn10 vector (example 6) was digested with NheI and ApaI and the empty vector fragment was isolated. This linear fragment and the final PCR products generated in example 8.1 and 8.3 were cloned and transformed simultaneously by in vivo recombination (Butler, T. and Alcalde, M. 2003. In Methods in Molecular Biology, vol. 231: (F. H. Arnold and G. Georgiou, editors), Humana Press Inc. Totowa (New Jersey), pages 17-22).
The YEpFLAGΔKpn10 vector (example 6) was digested with NheI and SstII and the empty vector fragment was isolated. This linear fragment and the final PCR products generated in example 8.2 were cloned and transformed simultaneously by in vivo recombination.
Example 8
Medium Scale Expression of Native and Modified Family 6 Cellulases in Yeast
One isolated colony of BJ3505 yeast containing YEpFLAG-ΔKpn10-cbh2 was used to inoculate 5 mL of liquid SC-trp in a 20 mL test-tube. After an overnight incubation at 30° C. and 250 rpm, optical density at 600 m was measured and 50 mL of YPEM liquid media in a 250 mL Erlenmeyer flask was inoculated with the amount of yeast required to get a final OD 600 of 0.045. After 72 h of incubation at 30° C. and 250 rpm, supernatant was harvested with a 5 minutes centrifugation step at 3,000×g. The BJ3505 strains expressing the TrCel6A variants, wild-type HiCel6A and variant, wild-type PcCel6A and variant as well as the empty YEpFLAG-1 vector were cultured the same way.
SC-trp liquid media contains the same components as the SC-trp plate mentioned in example 7 without the agar. YPEM liquid media contains:
Component
per Liter
Yeast Extract (BD)
10
g
Peptone (BD)
5.0
g
Glucose (Fisher)
10
g
Glycerol (Fisher)
30
mL
Example 9
Characterization of Modified Family 6 Cellulases from Yeast Culture Supernatants
9.1 Comparison of the thermophilicity of the Modified TrCel6A with the Native TrCel6A.
The thermophilicity of each enzyme was determined by measuring the release of reducing sugars from a soluble β-glucan substrate at different temperatures. Specifically, in a 300 μL PCR plate, 50 μL of crude supernatant obtained as per Example 9 was mixed with 50 μL of pre-heated 1% (w/v) β-glucan (Barley, Medium Viscosity; Megazyme) in 55 mM sodium citrate pH 5.0 in 10 different columns of a 96-well PCR plate. Mixtures were incubated for 30 min. at 10 different temperatures of a gradient (56, 58.1, 59.8, 62.6, 66, 70, 73.4, 76.2, 78.1 and 80° C.) then released reducing sugars were measured as follows: 100 μL of DNS reagent was added to each well and the plate was incubated 20 minutes at 95° C.
DNS reagent contains:
Component
g/L
3,5-Dinitosalicylic acid (Acros)
10
Sodium hydroxide (Fisher)
10
Phenol (Sigma)
2
Sodium metabisulfate (Fisher)
0.5
Once the temperature decreased below 40° C., 135 μL of each reaction mixture was transferred to individual wells of a 96-well microplate containing 65 μL of Rochelle salts (40% Sodium potassium tartrate) in each well and OD 560 was measured using a Fluostar Galaxy microplate reader equipped with a 560 nm filter. Blank value was measured by treating the supernatant from the strain carrying the empty vector the same way and was subtracted to each value. Then activity was expressed in percentage relatively to the highest value of the four parameters Polynomial fit for each variant except variant TrCel6A-G231S-N305S-R410Q-S413P for which a four parameters Log Normal fit was used ( FIG. 6 ).
All modified Family 6 cellulases shown an improved optimal temperature when compared to their respective wild-type except variant TrCel6A-G231S-N305S-R40Q-S413P which on the other hand exhibits a broad temperature range with more then 80% of the maximum activity ( FIG. 6 ). Among all TrCel6A variants, TrCel6A-S413P has the higher optimal temperature at 72.2° C., an increase of 5.6° C. compared to wild-type TrCel6A ( FIG. 6 a ). PcCel6A-S407P and HiCel6A-Y420P also exhibit an increase in optimal temperature when compared to their respective wild-type ( FIGS. 6 b and c ).
9.2 Comparison of the Alkalophilicity of the Modified TrCel6A with the Native TrCel6A.
The alkalophilicity of each enzyme was determined by measuring the release of reducing sugars from a soluble β-glucan substrate at different pH. Specifically, in a 300 μL PCR plate, 50 μL of crude supernatant obtained as per example 9 was mixed to 50 μL of pre-heated 1% (w/v) β-glucan (Barley, Medium Viscosity; Megazyme) in 55 mM sodium citrate, 55 mM sodium phosphate pH 3.0, 4.0, 5.0, 5.75, 6.25, 6.75, 7.25 or 8.5 in 8 different columns of the plate (once mixed to the supernatant and heated at 60-65° C., pHs where 3.95, 4.65, 5.65, 6.25, 6.65, 6.95, 7.15 and 7.45 respectively). Mixtures were incubated 30 min. at 65° C. (60° C. for PcCel6A and variant) then released reducing sugars were measured as per Example 10.1. Background activity from the yeast host was measured by treating the supernatant from the strain carrying the empty vector the same way and this activity was subtracted from the activity value for each variant. Then activity was expressed in percentage relatively to the highest value of the three parameter mechanistic fit for each variant ( FIG. 7 ).
All modified Family 6 cellulases exhibit increased alkalophilicity when compared to their wild-type. For TrCel6A, the most important shift was observed with variants TrCel6A-G231S-R410Q-S413P (+1.25 pH units) followed by TrCel6A-G231S-N305S-R410Q-S413P (+1.01 pH units).
9.3 Comparison of the Thermostability of the Modified TrCel6A with the Native TrCel6A.
The thermostability of each enzyme was determined by measuring the release of reducing sugars from a soluble β-glucan substrate after different pre-incubation time of the supernatant at 60° C. (55° C. for PcCel6A and variant). Specifically, in a 300 μL PCR plate, 50 μL of crude supernatant obtained as per Example 9 was incubated at 60° C. (55° C. for PcCel6A and variant) for 0, 15, 30, 45, 60, 75, 90 and 120 minutes. Then, 50 μL of 1% (w/v) β-glucan (Barley, Medium Viscosity; Megazyme) in 55 mM sodium citrate pH 5.0 was added and mixtures were incubated 30 minutes 65° C. (60° C. for PcCel6A and variant). Released reducing sugars were then measured as per Example 10.1. Background activity from the yeast host was measured by treating the supernatant from the strain carrying the empty vector the same way and this activity was subtracted from the activity value for each variant. Finally, activity was expressed in percentage relatively to the highest value of the three parameter single exponential decay fit for each variant ( FIG. 5 ).
All TrCel6A variants have shown increased thermostability when compared to wild-type TrCel6A ( FIG. 5 a ). The S413P mutation results in a significant increase in the thermostability TrCel6A. TrCel6A-S413P retains 45% of its activity after 60 minutes at 60° C. whereas TrCel6A retains only 4% of its activity after 60 minutes. This represents a greater improvement in thermostability compared to that of the TrCel6A-S413Y variant disclosed in US Patent Publication No. 20060205042, which retained on average 41% of its activity under similar conditions. The highest improvement was observed with TrCel6A-R410Q-S413P and TrCel6A-G231S-R410Q-S413P as both retain 58 and 60% of their activity after 60 minutes at 60° C. respectively. Similarly to TrCel6A, PcCel6A-S407P retains 38% of its activity after 60 minutes at 55° C. whereas PcCel6A retains only 6% of its activity after 60 minutes ( FIG. 5 b ). This supports the claim for which a proline at the equivalent position of TrCel6A residue 413 increases thermostability.
9.4 Comparison of the T 50 of the Modified TrCel6A with the Native TrCel6A.
T 50 herein is defined as the temperature at which the crude yeast supernatant retains 50% of its β-glucan hydrolyzing activity after 15 minutes of incubation without substrate. It was determined by measuring the release of reducing sugars from a soluble β-glucan substrate after 15 minutes of pre-incubation at different temperatures. Specifically, in a 300 μL PCR plate, 50 μL of crude supernatant obtained as per Example 9, was incubated at 45, 49.2, 53.9, 57.7, 59.5, 60.4, 62.5, 64.2, 66.4, 68.9, 72.7 or 75° C. for 15 minutes. Then, 50 μL of 1% (w/v) β-glucan (Barley, Medium Viscosity; Megazyme) in 55 mM sodium citrate pH 5.0 was added and mixtures were incubated 30 minutes 65° C. (60° C. for PcCel6A and variant). Released reducing sugars were then measured as per Example 10.1. Background activity from the yeast host was measured by treating the supernatant from the strain carrying the empty vector the same way and this activity was subtracted from the activity value for each variant. Finally, activity was expressed in percentage relatively to the highest value of the four parameter sigmoid fit for each variant ( FIG. 4 ).
The T 50 of the TrCel6A-S413P was determined to be 64.1° C., as compared to 59° C. for the parent TrCel6A ( FIG. 4 a ). This represents an increase in the thermostability by over 5° C. through the introduction of the S413P mutation. This represents a significant improvement in enzyme stability compared to the S413Y mutation disclosed US Patent Publication No. 20060205042, which shows a very modest 0.2-0.3° C. increase in the Tm of the TrCel6A-S413Y over TrCel6A. Although the methods to determine the Tm disclosed US Patent Publication No. 20060205042 is different from the determination of T50 disclosed herein, both methods seek to determine the temperature at which the protein undergoes a significant and structural change that leads to irreversible inactivation. The T 50 of the other TrCel6A variants was at least 3.2° C. higher then wild-type TrCel6A.
PcCel6A-S407P and Hicel6A-Y420P also have shown an increase in TSO when compared to their respective parent enzyme ( FIGS. 4 b and c ). This also supports the claim for which a proline at the equivalent position of TrCel6A residue 413 increases thermostability in Family 6 cellulases.
Example 10
Making Genetic Constructs Comprising Modified Family 6 Cellulase DNA Sequences
10.1 Isolation of Trichoderma reesei Genomic DNA and Construction of T. reesei Genomic Libraries
A strain of Trichoderma reesei obtained derived from RutC30 (ATCC #56765; Montenecourt, B. and Eveleigh. D. 1979 . Adv. Chem. Ser. 181: 289-301) comprising a disrupted native TrCel6A gene was used. RutC30 is derived from Trichoderma reesei Qm6A (ATCC # 13631; Mandels, M. and Reese, E. T. 1957 . J. Bacteriol. 73: 269-278). It is well understood by those skilled in the art that the procedures described herein, the genetic constructs from these strains, and the expression of the genetic constructs in these strains are applicable to all Trichoderma strains derived from Qm6A.
To isolate genomic DNA, 50 mL of Potato Dextrose Broth (Difco) was inoculated with T. reesei spores collected from a Potato Dextrose Agar plate with a sterile inoculation loop. The cultures were shaken at 200 rpm for 2-3 days at 28° C. The mycelia was filtered onto a GFA glass microfibre filter (Whatman) and washed with cold, deionized water. The fungal cakes were frozen in liquid nitrogen crushed into a powder with a pre-chilled mortar and pestle; 0.5 g of powdered biomass was resuspended in 5 mL of 100 mM Tris, 50 mM EDTA, pH 7.5 plus 1% sodium dodecyl sulphate (SDS). The lysate was centrifuged (5000 g for 20 min, 4° C.) to pellet cell debris. The supernatant was extracted with 1 volume buffer (10 mM Tris, 1 mM EDTA, pH 8.0) saturated phenol followed by extraction with 1 volume of buffer-saturated phenol:chloroform:isoamyl alcohol (25:24:1) in order to remove soluble proteins. DNA was precipitated from the solution by adding 0.1 volumes of 3 M sodium acetate, pH 5.2 and 2.5 volumes of cold 95% ethanol. After incubating for at least 1 h at −20° C., the DNA was pelleted by centrifugation (5000 g for 20 min, 4° C.), rinsed with 10 mL 70% ethanol, air-dried and resuspended in 1 mL 10 mM Tris, 1 mM EDTA, pH 8.0. RNA was digested by the addition of Ribonuclease A (Roche Diagnostics) added to a final concentration of 0.1 mg/mL and incubation at 37° C. for 1 hour. Sequential extractions with 1 volume of buffer-saturated phenol and 1 volume of buffer-saturated phenol:chloroform:isoamyl alcohol (25:24:1) was used to remove the ribonuclease from the DNA solution. The DNA was again precipitated with 0.1 volumes of 3 M sodium acetate, pH 5.2 and 2.5 volumes of cold 95% ethanol, pelleted by centrifugation, rinsed with 70% ethanol, air-dried and resuspended in 50 μL of 10 mM Tris, 1 mM EDTA, pH 8.0. The concentration of DNA was determined by measuring the absorbance of the solution at 260 nm (p. C1 in Sambrook et al., Molecular Cloning: A Laboratory Manual, Second Edition, Cold Spring Harbor Press 1989, which is incorporated herein by reference, and hereafter referred to as Sambrook et al.).
Two plasmid libraries and one phage library were constructed using genomic DNA isolated from T. reesei strain M2C38. The plasmid libraries were constructed in the vector pUC119 (Viera and Messing, Methods Enzymol. 153:3, 1987) as follows: 10 μg genomic DNA was digested for 20 hrs at 37° C. in a 100 μL volume with 2 units/μg of BamH1 or EcoR1 restriction enzymes. The digested DNA was fractionated on a 0.75% agarose gel run in 0.04 M Tris-acetate, 1 mM EDTA and stained with ethidium bromide. Gel slices corresponding to the sizes of the genes of interest (based on published information and Southern blots) were excised and subjected to electro-elution to recover the DNA fragments (Sambrook et al., pp. 6.28-6.29). These enriched fractions of DNA were ligated into pUC119 in order to create gene libraries in ligation reactions containing 20-50 μg/mL DNA in a 2:1 molar ratio of vector:insert DNA, 1 mM ATP and 5 units T4 DNA ligase in a total volume of 10-15 μL at 4° C. for 16 h. Escherichia coli strain HB101 was electroporated with the ligation reactions using the Cell Porator System (Gibco/BRL) following the manufacturer's protocol and transformants selected on LB agar containing 70 μg/mL ampicillin.
The phage library was constructed in the vector λDASH (Stratagene, Inc.) as follows: genomic DNA (3 μg) was digested with 2, 1, 0.5 and 0.5 units/μg BamHI for 1 hour at 37° C. to generate fragments 9-23 kB in size. The DNA from each digest was purified by extraction with 1 volume Tris-staturated phenol:choroform:isoamyl alcohol (25:24:1), followed by precipitation with 10 μL 3 M sodium acetate, pH 5.2 and 250 μl 95% ethanol (−20° C.). The digested DNA was pelleted by microcentrifugation, rinsed with 0.5 mL cold 70% ethanol, air-dried and resuspended in 10 μL sterile, deionized water. Enrichment of DNA fragments 9-23 kB in size was confirmed by agarose gel electrophoresis (0.8% agarose in 0.04 M Tris-acetate, 1 mM EDTA). Digested DNA (0.4 μg) was ligated to 1 μg λDASH arms predigested with BamHI (Stratagene) in a reaction containing 2 units T4 DNA ligase and 1 mM ATP in a total volume of 5 μl at 4° C. overnight. The ligation mix was packaged into phage particles using the GigaPack® II Gold packaging extracts (Stratagene) following the manufacturer's protocol. The library was titred using the E. coli host strain XL1-Blue MRA (P2) and found to contain 3×10 5 independent clones.
10.2 Cloning the Cellobiohydrolase I (cbh1) and Cellobiohydrolase II (cbh2) Genes from pUC119 Libraries
E. coli HB101 transformants harboring cbh1 or cbh2 clones from recombinant pUC119-BamH1 or -EcoRI libraries were identified by colony lift hybridization: 1−3×10 4 colonies were transferred onto HyBond™ nylon membranes (Amersham); membranes were placed colony-side up onto blotting paper (VWR 238) saturated with 0.5 M NaOH, 1 M NaCl for 5 min to lyse the bacterial cells and denature the DNA; the membranes were then neutralized by placing them colony-side up onto blotting paper (VWR 238) saturated with 1.5 M Tris, pH 7.5 plus 1 M NaCl for 5 min; the membranes were allowed to air-dry for 30 min and the DNA was then fixed to the membranes by baking at 80° C. for 2 h.
32 P-labelled probes were prepared by PCR amplification of short (0.7-1.5 kB) fragments of the cbh1 and cbh2 coding regions from the enriched pool of BamH1 or EcoR1 fragments, respectively, in a labelling reaction containing 10-50 ng target DNA, and 0.2 mM each of d(GCT)TP, 0.5 μM dATP, 20-40 μCi α- 32 P-dATP, 10 pmole oligonucleotide primers and 0.5 units Taq polymerase in a total volume of 20 μL. The reaction was subjected to 6-7 cycles of amplification (95° C., 2 min; 56° C., 1.5 min; 70° C., 5 min). The amplified, 32 P-labelled DNA was precipitated by the addition of 0.5 mL 10% (w/v) trichloroacetic acid and 0.5 mg yeast tRNA. The DNA was pelleted by microcentrifugation, washed twice with 1 mL 70% ethanol, air-dried and resuspended in 1 M Tris pH 7.5, 1 mM EDTA.
Nylon membranes onto which the recombinant pUC119 plasmids had been fixed were prehybridized in heat-sealed bags for 1 h at 60-65° C. in 1 M NaCl, 1% SDS, 50 mM Tris, 1 mM EDTA pH 7.5 with 100 μg/mL denatured sheared salmon sperm DNA. Hybridizations were performed in heat-sealed bags in the same buffer with only 50 μg/mL denatured sheared salmon sperm DNA and 5×10 6 -5×10 7 cpm of denatured cbh1 or cbh2 probe for 16-20 h at 60-65° C. Membranes were washed once for 15 min with 1 M NaCl, 0.5% SDS at 60° C., twice for 15 min each with 0.3M NaCl, 0.5% SDS at 60° C. and once for 15 min with 0.03M NaCl, 0.5% SDS at 55° C. Membranes were again placed in heat-sealed bags and exposed to Kodak RP X-ray film to 16-48 h at −70° C. The X-ray film was developed following the manufacturer's protocols. Colonies giving strong or weak signals were picked and cultured in 2×YT media supplemented with 70 μg/mL ampicillin. Plasmid DNA was isolated from these cultures using the alkaline lysis method (Sambrook, et al., pp. 1.25-1.28) and analyzed by restriction digest, Southern hybridization (Sambrook, et al., pp. 9.38-9.44) and PCR analysis (Sambrook, et al., pp. 14.18-14,19).
Clones carrying the cbh1 gene were identified by colony lift hybridization of the pUC119-BamH1 library with a 0.7 kb cbh1 probe prepared using oligonucleotide primers designed to amplify bp 597-1361 of the published cbh1 sequence (Shoemaker et al., Bio/Technology 1: 691-696, 1983; which is incorporated herein by reference). A cbh1 clone, pCOR132, was isolated containing a 5.7 kb BamH1 fragment corresponding to the promoter (4.7 kb) and 1 kb of the cbh1 structural gene (2.3 kb). From this, a 2.5 kb EcoR1 fragment containing the cbh1 promoter (2.1 kb) and 5′ end of the cbh1 coding region (0.4 kb) was subcloned into pUC119 to generate pCB152. Clones carrying the cbh2 gene were identified by colony lift hybridization of the pUC119-EcoR1 library with a 1.5 kb cbh2 probe prepared using oligonucleotide primers designed to amplify bp 580-2114 of the published cbh2 sequence (Chen et al. Bio/Technology 5: 274-278, 1987). A cbh2 clone, pZUK600 was isolated containing a 4.8 kb EcoR1 fragment corresponding to the promoter (600 bp), structural gene (2.3 kb) and terminator (1.9 kb).
10.3 Cloning Xylanase II (xln2) gene from λDASH Libraries
Digoxigen-11-dUTP labelled probes were prepared from PCR amplified coding regions of the xln2 gene by random prime labeling using the DIG Labeling and Detection kit (Roche Diagnostics) and following the manufacturer's protocols. Genomic clones containing the xln2 gene were identified by plaque-lift hybridization of the λDASH library. For each gene of interest, 1×10 4 clones were transferred to Nytran® (Schleicher and Schull) nylon membranes. The phage particles were lysed and the phage DNA denatured by placing the membranes plaque-side up on blotting paper (VWR238) saturated with 0.5 M NaOH, 1 M NaCl for 5 min. The membranes were then neutralized by placing them plaque-side up onto blotting paper saturated with 1.5 M Tris, pH 7.5 plus 1 M NaCl for 5 min and subsequently allowed to air-dry for 30 min. The DNA was then fixed to the membranes by baking at 80° C. for 2 h. The membranes were prehybridized in heat-sealed bags in a solution of 6× SSPE, 5× Denhardt's, 1% SDS plus 100 μg/mL denatured, sheared salmon sperm DNA at 65° C. for 2 h. The membranes were then hybridized in heat-sealed bags in the same solution containing 50 μg/mL denatured, sheared salmon sperm DNA and 0.5 μg of digoxigen-dUTP labelled probes at 65° C. overnight. The membranes were washed twice for 15 min in 2× SSPE, 0.1% SDS at RT, twice for 15 min in 0.2× SSPE, 0.1% SDS at 65° C. and once for 5 min in 2× SSPE. Positively hybridizing clones were identified by reaction with an anti-digoxigenin/alkaline phosphatase antibody conjugate, 5-bromo-4-chloro-3-indoyl phosphate and 4-nitro blue tetrazolium chloride (Roche Diagnostics) following the manufacturer's protocol. Positively hybridizing clones were further purified by a second round of screening with the digoxigen-dUTP labelled probes.
Individual clones were isolated and the phage DNA purified as described in Sambrook et al. pp. 2.118-2.121 with the exception that the CsCl gradient step was replaced by extraction with 1 volume of phenol:choroform:isoamyl alcohol (25:24:1) and 1 volume of chloroform:isoamyl alcohol (24:1). The DNA was precipitated with 0.1 volumes of 3 M sodium acetate, pH 5.2 and 2.5 volumes cold 95% ethanol. The precipitated phage DNA was washed with 0.5 mL cold 70% ethanol, air-dried and resuspended in 50 μL 10 mM Tris, 1 mM EDTA pH 8.0. Restriction fragments containing the genes of interest were identified by restriction digests of the purified phage DNA and Southern blot hybridization (Sambrook, et al., pp. 9.38-9.44) using the same digoxigen-dUTP labelled probes used to screen the λDASH library. The membranes were hybridized and positively hybridizing fragments visualized by the same methods used for the plaque lifts. Once the desired restriction fragments from each λDASH clone were identified, the restriction digests were repeated, the fragments were resolved on a 0.8% agarose gel in TAE and the desired bands excised. The DNA was eluted from the gel slices using the Sephaglas B and Prep Kit (Pharmacia) following the manufacturer's protocol.
Clones carrying the xln2 gene were identified by colony lift hybridization of the λDASH library (Example 7) with a xln2 probe comprising bp 100-783 of the published xln2 sequence (Saarelainen et al., Mol. Gen. Genet. 241: 497-503, 1993). A 5.7 kb Kpn1 fragment containing the promoter (2.3 kb), coding region (0.8 kb) and terminator (2.6 kb) the xln2 gene was isolated by restriction digestion of phage DNA purified from a λDASH xln2 clone. This fragment was subcloned into the Kpn1 site of pUC119 to generate the plasmid pXYN2K-2.
10.4: Construction of a Vector Directing the Expression of Modified Family 6 Cellulase in Trichoderma reesei.
A 2.3 kb fragment containing the promoter and secretion signal of the xln2 gene (bp −2150 to +99 where +1 indicates the ATG start codon and +97-99 represent the first codon after the TrXyl11 secretion signal peptide) was amplified with Pwo polymerase from the genomic xln2 subclone pXYN2K-2 (Example 7) using an xln2-specific primer containing a NheI directly downstream of the Gln at codon 33 and the pUC reverse primer (Cat. No. 18432-013, Gibco/BRL) which anneals downstream of the Kpn1 site at the 5′ end of the xln2 gene. This xlz2 PCR product was inserted as a blunt-ended fragment into the SmaI site of the pUC119 polylinker in such an orientation that the BamHI site of the polylinker is 3′ to the NheI site; this generated the plasmid pUC/XynPSS(Nhe). The same xln2 PCR product was reisolated from pUC/XynPSS(Nhe) by digestion with EcoRI (which was amplified as part of the pUC119 polylinker from pXYN2K-2) and BamHI and inserted into the plasmid pBR322L (a derivative of pBR322 containing an Sph1-Not1-Sal1 adaptor between the original Sph1 and Sal1 sites at bp 565 and 650), also digested with EcoRI and BamHI, to generate the plasmid pBR322LXN. To facilitate high level expression of the modified xylanases, a 1.3 kb HindIII fragment comprising bp −1400 to −121 of the xln2 promoter in pBR322LXN was replaced with a 1.2 kb HindIII fragment comprising bp −1399 to −204 of the cbh1 promoter which was isolated by HindIII digestion of pCOR132; this generated the plasmid pBR322LC/XN. Finally, the EcoR1 site of pBR322LXC was then blunted with Klenow and Spe1 linkers (Cat. No. 1086, New England Biolabs) were added to generate pBR322SpXC.
A fragment containing the TrCel6A-S413P gene was isolated from the YEpFLAGΔKpn10-cbh2 vector (described in Example 6 above) by digestion with NheI and KpnI inserted into pCB219N-N digested with NheI and BamHI to generate pS413P/C2ter. To make pCB219N-N, a cbh2 terminator fragment was amplified from the pZUK600 (described in Example 7, above) template using a primer homologous to bp 2226-2242 of the published 3′ untranslated region of the cbh2 gene (Chen et al., 1987) containing a short polylinker comprising XbaI-NheI-BamHI-SmaI-KpnI sites at the 5′ end and the pUC forward primer (Cat. No. 1224, New England Biolabs) which anneals upstream of the EcoR1 site at the 3′ end of cbh2 in pZUK600. This fragment was digested at the engineered XbaI and EcoRI sites and inserted into the corresponding sites of pUC119 to generate pCB219. An EcoR1-Not1 adaptor (Cat. No. 35310-010, Gibco/BRL) was inserted into the unique EcoR1 site of pCB219 to generate pCB219N. A fragment comprising the TrCel6A gene and the cbh2 terminator was isolated from pS413P/C2ter by digestion with NheI and NotI and inserted into pBR322SpXC digested with NheI and NotI to generate the expression cassette pc/xS413P-EC.
The selection cassette containing plasmid, pNCBgINSNB(r), was derived from a N. crassa pyr4 containing plasmid, pFB6 (Radford, A., Buston, F. P., Newbury, S. F. and Glazebrook, J. A. (1985) Regulation of pyrimidine metabolism in Neurospora . In Molecular Genetics of Filamentous Fungi (Timberlake, W. E., editor), Alan R. Liss (New York), pages 127-143). A 3.2 kb BglII fragment from pFB6 containing the N. crassa pyr4 gene (GenBank accession M13448) as well as its promoter, terminator and some 5′ UTR sequences was cloned into the BamHI site of pUC119 modified to contain NotI, SmaI, NheI and BglII sites in the polylinker (between EcoRI and SacI) to generate pNCBgl-NSNB(r). An SpeI/NotI fragment comprising the TrCel6A-S413P gene operably linked to the cbh1 promoter, xln2 secretion signal peptide and cbh2 transcriptional terminator was isolated from the expression cassette vector pc/xS413P-EC and inserted into pNCBgl-NSNB(r) digested with NheI (SpeI and NheI having compatible 5′ overhanging sequences) and NotI to generate p c / x -S413P-TV. This final construct was linearized by NotI prior to transformation of Trichoderma reesei.
Example 11
Transformation of the Trichoderma reesei
11.1 Isolation of pyr4 Auxotrophs
In order to use the N. crassa pyr4 gene as a selectable marker, a spontaneous pyr4 auxotroph was isolated as follows: 1×10 6 spores of T. reesei were plated onto minimal media containing 5 mM uridine and 0.15% (w/v) of the uridine analog 5-fluoroorotic acid (FOA) as previously described for the selection of pyr4 auxotrophs of T. reesei (Berges, T. and Barreau, C. 1991 Curr Genet. 19(5):359-65). The ability to grow on FOA-containing media will allow for selection of mutants disrupted in either the pyr2 gene encoding orotate phosphoribosyl transferase or the pyr4 gene encoding orotidine 5′-phosphate decarboxylase. Spontaneous FOA-resistant colonies were subjected to secondary selection of minimal media with and without uridine. Spores of FOA-resistant colonies that could not grow on minimal media were then transformed with pNCBglNSNB(r) (described in Example 11.4) and selected for growth on minimal media. Only those strains that were complemented by the N. crassa pyr4 gene in pNCBgINSNB(r) will grow on minimal media and are true pyr4 auxotrophs. Using these procedures, a stable pyr4 auxotroph of T. reesei was obtained.
11.2 Transformation of Protoplasts of T. reesei pyr4 Auxotrophs.
5×10 6 spores of T. reesei were plated onto sterile cellophane on Potato Dextrose agar supplemented with 5 mM uridine and are incubated for 20 hours at 30° C. to facilitate spore germination and mycelial growth. Cellophane discs with mycelia were transferred to 10 mL of a protoplasting solution containing 7.5 g/L Driselase and 125 units of protease free β-glucanase (InterSpex Products Inc., Cat. Nos. 0465-1 and 0410-3, respectively) in 50 mM potassium phosphate buffer, pH 6.5 containing 0.6 M ammonium sulfate (Buffer P). The mycelial mat was digested for 5 hours with shaking at 60 rpm. Protoplasts were separated from undigested mycelia by filtration through sterile No. 30 MIRACLOTH™ and collected into a sterile 50 mL round-bottom centrifuge tube and recovered by centrifugation at 1000-1500×g for 10 min at room temperature. Protoplasts were washed with 5 mL of Buffer P and centrifuged again at 1000-1500×g for 10 min at room temperature. Protoplasts were resuspended in 1 mL of STC buffer (1.2 M sorbitol, 10 mM CaCl 2 , 10 mM Tris-HCL, pH 7.5). For transformation, 0.1 mL of resuspended protoplasts were combined with 10 μg of vector DNA and 25 μL of PEG solution (25% PEG 4000, 50 mM CaCl 2 , 10 mM Tris-HCl, pH 7.5). After incubation in an ice water bath for 30 min, 1 mL of PEG solution was added and the mixture incubated for 5 min at room temperature. Transformation mix was diluted with 2 mL of 1.2 M sorbitol in PEG solution and the entire mix was added to 25 mL of molten MMSS agar media (see below) cooled to about 47° C. and the protoplast suspension poured over MMSS agar. Plates were incubated at 30° C. until colony growth was visible. Transformants were transferred to individual plates containing MM agar and allowed to sporulate. Spores were collected and plated at high dilution on MM agar to isolate homokaryon transformants, which were then plated onto PDA to allow for growth and sufficient sporulation to inoculate the screening cultures as described in Example 13 below.
Minimal medium (MM) agar contains the following components:
Reagent
Per L
KH 2 PO 4
10
g
(NH 4 ) 2 SO 4
6
g
Na 3 Citrate•2H 2 O
3
g
FeSO 4 •7H 2 O
5
mg
MnSO 4 •H 2 O
1.6
mg
ZnSO 4 •7H 2 O
1.4
mg
CaCl 2 •2H 2 O
2
mg
Agar
20
g
20% Glucose f.s.
50
mL
1 M MgSO 4 •7H 2 O f.s.
4
mL
pH to 5.5
MMSS agar contains the same components as MM agar plus 1.2 M sorbitol, 1 g/L YNB (Yeast Nitrogen Base w/o Amino Acids from DIFCO Cat. No. 291940) and 0.12 g/L amino acids (-Ura DO Supplement from BD Biosciences Cat. No. 630416).
Example 12
Production of Modified Family 6 Cellulases in Liquid Cultures
Individual colonies of Trichoderma were transferred to PDA plates for the propagation of each culture. Sporulation was necessary for the uniform inoculation of the micro-cultures used in testing the ability of the culture to produce the modified TrCelA. variants with increased thermostability. The culture media is composed of the following:
Component g/L (NH 4 ) 2 SO 4 12.7 KH 2 PO 4 8.00 MgSO 4 •7H 2 O 4.00 CaCl 2 •2H 2 O 1.02 Corn Steeped Liquor 5.00 CaCO 3 20.00 Carbon source** 30-35 Trace elements* 2 mL/L
*Trace elements solution contains 5 g/L FeSO 4 .7H 2 0; 1.6 g/L MnSO 4 .H 2 0; 1.4 g/L ZnSO 4 .7H 2 0.** glucose, Solka floc, lactose, cellobiose, sophorose, corn syrup, or Avicel. The carbon source can be sterilized separately as an aqueous solution at pH 2 to 7 and added to the remaining media initially or through the course of the fermentation.
Individual transformants were grown in the above media in 1 mL cultures in 24-well micro-plates. The initial pH was 5.5 and the media sterilized by steam autoclave for 30 minutes at 121° C. prior to inoculation. For both native and transformed cells, spores were isolated from the PDA plates, suspended in water and 10 4 -10 5 spores per mL were used to inoculate each culture. The cultures were shaken at 500 rpm at a temperature of 30° C. for a period of 6 days. The biomass was separated from the filtrate containing the secreted protein by centrifugation at 12,000 rpm. The protein concentration was determined using the Bio-Rad Protein Assay (Cat. No. 500-0001). Expression of TrCelA-S413P was determined as described in Example 14.
Example 13
Characterization of T. reesei Culture Filtrates Comprising Modified Family 6 Cellulases
The expression of TrCel6A-S413P in culture filtrates of T. reesei transformants was determined by Western blot hybridization of SDS-PAGE gels. Specifically, equal amounts of total secreted protein in 10-20 μL of culture filtrate from the TrCel6A-S413P transformants, the parent strain P107B and a strain expressing the native, unmodified TrCel6A (strain BTR213) were added to an equal volume of 2× Laemmli buffer (0.4 g SDS/2 mL glycerol/1 mL 1M Tris-HCl, pH 6.8/0.3085 g DTT/2 mL 0.5% bromophenol blue/0.25 mL β-mercaptoethanol/10 mL total volume). 10 uL of each prepared sample was resolved on a 10% SDS polyacrylamide gel using 24 mM Tris, 192 mM glycine pH 6.8, 10 mM SDS as running buffer. The separated proteins were transferred electrophoretically from the acrylamide gel to a PVDF membrane, prewetted with methanol, in 25 mM Tris/192 mM glycine buffer containing 20% methanol. The membrane was subsequently washed in 30 mL of BLOTTO buffer (5% skim milk powder in 50 mM Tris-HCl, pH 8.0). The membrane was probed with 30 mL of a 1:20,000 dilution of polyclonal antibodies specific to TrCel6A in BLOTTO overnight at room temperature, washed twice more for 10 min with an equal volume of BLOTTO at room temperature, then probed for 1 hour with a 1:3000 dilution of goat anti-rabbit/alkaline phosphatase conjugate in BLOTTO at room temperature. Finally, the membrane was washed twice for 15 min each at room temperature with an excess of 50 mM Tris-HCl, pH 8.0. Hybridizing complexes containing TrCel6A were visualized by treatment of the membrane with 10 mL of a 100 mM NaCl/100 mM Tris-HCl, pH 9.5 buffer containing 45 μl of 4-nitro blue tetrazolium chloride (Roche Diagnostics) and 35 μL of 5-bromo-4-chloro-3-indoyl phosphate (Roche Diagnostics) at room temperature until bands were clearly visible. Positively hybridizing bands of ˜60 kDa were observed in the culture filtrates from most transformants, the positive control strain BTR213, but not from the culture filtrate from strain P107B. Transformant P474B expresses and secretes approximately the same level of TrCel6A-S413P as the amount of unmodified TrCel6A expressed and secreted by the control strain BTR213.
The stability of the Trichoderma cellulases containing TrCel6A or TrCel6A-S413P was assessed incubation of the cellulases in 50 mM citrate buffer, pH 4.8 at 50° C. for up to 96 hours and then measuring the residual activity of the cellulase by nephelometry (Enari, T. M. and Niku-Paavola M. L. 1988. Meth. Enzym. 160: 117-126).
While the rate of cellulose hydrolysis by the untreated TrCel6A and TrCel6A-S413P cellulases was identical, after incubation for up to 96 hours in the absence of substrate, the TrCel6A-S413P cellulase maintained much higher activity than the TrCel6A cellulase ( FIG. 8 ). Thus, improvements in the thermostability of TrCel6A also improved the thermostability of a whole Trichoderma cellulase system comprising the modified Family 6 cellulase and other components.
The present invention has been described with regard to preferred embodiments. However, it will be obvious to persons skilled in the art that a number of variations and modifications can be made without departing from the scope of the invention as described herein.
All references and citations are herein incorporated by reference.
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Zhang S, et al. 2000. Eur. J. Biochem. 267:3101-15. | A modified Family 6 cellulase enzyme comprising a proline residue at position 413 is provided. Genetic constructs and genetically modified microbes comprising DNA sequences encoding the modified Family 6 cellulase are also provided. Family 6 cellulases of the invention display improved thermostability, thermophilicity, alkalophilicity, or a combination thereof, relative to the parent Family 6 cellulases. Such cellulases find use in a variety of applications in industry that require cellulase stability and activities at temperatures, pH values, or both, above that of the native enzyme. | 2 |
RELATED APPLICATIONS
[0001] This application claims benefit to US provisional application 60/740,222 filed Nov. 28, 2005 which is incorporated by reference in its entirety for all useful purposes.
GOVERNMENT LICENSE RIGHTS
[0002] The United States Government has rights in this invention as provided for by NASA Genetically Engineering Polymer Contract or grant no(s): MASC 372116 and NSF EPSCoR Grant No. EPS-0447610.
BACKGROUND OF THE INVENTION
[0003] The investigation of structure/property relationships in materials often requires processing prior to the measurement of their properties. Fiber spinning is often the processing method of choice in long chain polymers because of the subsequent chain alignment that occurs during the shear and windup process. This alignment can give rise to highly anisotropic electrical, mechanical and photonic properties. Unfortunately commercial spinning lines need large (5-10 lbs) quantities of starting material in order to produce melt-spun fibers. This limits the candidates for investigation to those that are made in sufficiently large quantities and/or those that do not degrade at elevated temperatures, in the case of melt spinning. Solution spinning is possible as an alternative method but has been reserved for those polymers that dissolve in volatile and often times aggressive solvents (e.g., KEVLAR® in sulfuric acid). (KEVLAR® is a polyamide, in which all the amide groups are separated by para-phenylene groups, that is, the amide groups attach to the phenyl rings opposite to each other, at carbons 1 and 4 and is manufactured by DuPont), in sulfuric acid).
[0004] The electrospinning of fibers has been investigated for more than 30 years. However, since 1998 the number of publications on electrospun polymer nanofibers have grown exponentially, Z. M. Huang, Y. Z. Zhang, M. K. Kotaki and S. Ramakrishna, Composites Sci. and Tech. 2003, 63, 2223-2253 (“Huang”), US20030137069. Electrospinning, an offshoot of electrospraying, can be used to spin spider-web type fibers (see FIGS. 1-3 ) for characterization and testing of their mechanical and surface properties. The fibers produced during the electrospinning process are microscale and nanoscale, with diameters ranging (D. H. Reneker and I. Chun, Nanotechnology 1996, 7, 216 (“Reneker”)) from 40 nm to 5 μm compared to traditional textile fibers which have diameters (Reneker) of 5 to 200-μm. The primary advantage of electrospinning is that it uses minute quantities (as little as 10-15 mg) of polymer in solution to form continuous fibers. Although a number of commodity polymers have already been electrospun (Huang and S. Megelski, J. S. Stephens, D. B. Chase and J. F. Rabolt, Macromolecules 2002, 35, 8456 (“Megelski”), an understanding of the mechanism and parameters that affect the electrospinning process is only starting to emerge. There are a limited number of parameters that appear to effect the fiber diameter, the concentration of “beads”, the fiber surface morphology and the interconnectivity of polymer fibrils. These include solution concentration, distance between “nozzle” and target molecular weight of the polymer, spinning voltage, humidity, solvent volatility and solution supply rate. Although some of these (e.g., molecular weight, humidity) have been investigated in detail (C. Casper, J. Stephens, N. Tassi, D. B. Chase and J. Rabolt, Macromolecules 2004, 37, 573-578 (“Casper”) and Megelski most of the work has focused on investigation of the development of microstructure in fibers and their potential applications ranging from tissue engineering constructs to fuel cell membranes.
[0005] Electrospinning is a simple method that can prepare fibers with submicron diameter using electrostatic force. Submicron fibers prepared by this technique have recently come under intense scientific study due to wide ranging potential applications including filtration, optical fibers, protective textiles, drug delivery system, tissue engineering scaffolds, and gas separation membranes etc.
[0006] Many polymers, synthetic and natural, have been successfully spun into nano-, and/or micron-sized fibers from polymer solution and melt. Although polyolefin (CH 2 —CH 2 ) n , poly-α-olefin (CH 2 —(R—CH)) n , with R=aliphatic, aromatic or cyclic groups, their copolymers and/or their polymer blends are important commercial polymers, very limited work on the electrospinning of polyolefins, poly-α-olefins, their copolymers and/or their polymer blend fibers exists. In the case of polyolefins, poly-α-olefins, their copolymers and/or their polymer blends have limited solubility due to their excellent chemical resistance and non-polar structure, and hence are not easy to electrospin from solution. All investigations thus far have used melt-electrospinning.
BRIEF DESCRIPTION OF THE INVENTION
[0007] The invention relates to a process for producing a porous membrane with polyolefin classes of polymers using the electrospinning process. These polyolefin membranes and/or membranes made from poly-α-olefin, their copolymers and/or their polymer blends have a high surface area, small pore size, soft feel, flexibility and possess the possibility of producing 3-dimensional structures for use in filtration, protective textiles and gas separation etc.
[0008] Polyolefins and poly-α-olefins like polyethylene, polypropylene, poly-1-butene (PB), poly-1-pentene, poly-1-hexene, poly(3-methyl-1-butene), poly(4-methyl-1-pentene) (PMP), poly(4-methyl-1-hexene), poly(5-methyl-1-heptene),etc and their copolymers and polymer blends consist of hydrocarbon chains of varying lengths, etc, and are in general and/or special use in many industrial applications.
[0009] According to this invention, polyolefin, poly-α-olefin, their copolymers and/or their polymer blends are completely dissolved in a multi-component solvent system to form a clear or transparent solution indicating that gelation has hot occurred when heating from room temperature to a higher temperature depending on the polymer type, molecular weight and solvent system used. Room temperature is approximately 23° C. Upon cooling slowly from a temperature higher than room temperature to 25° C.-50° C. under ambient conditions results in a clear solution for electrospinning (K-H Lee, S. Givens, D. B. Chase and J. F. Rabolt, Polymer 2006, 47, 8013 (“Lee”))
[0010] Solubility of polyolefin class polymers depends strongly on the chemical structures and molecular weight. For example, poly(methyl-1-styrene) and polystyrene(PS) solutions can be prepared at room temperature while polyethylene, polypropylene, polybutene, and poly(4-methyl-1-pentene), etc solutions can not be prepared at room temperature. These polymers require heating for preparation of clear solutions for electrospinning. Tailoring the multi-component solvent system with a blend of solvent and non-solvent for the specific polyolefin class polymers allows for a disruption of chain-chain interactions yielding a clear solution for electrospinning at room temperature in polypropylene, polybutene, and poly(4-methyl-1-pentene), etc systems.
[0011] According to the invention, the polymer component is a single polyolefin or a mixture of polyolefins, where the polyolefins also include polyolefin copolymers and/or modified polyolefins. Mixtures of different polyolefins are very interesting due to varying physical properties such as mechanical, physical and thermal characteristics. For example, by adding a certain amount of poly(4-methyl-1-pentene) in poly(1-butene), thermal characteristics can be influenced, while adding certain amounts of a polyolefin with a high molecular weight can increase mechanical properties. In this case, high molecular weight polyolefins must be soluble in the solvent used.
[0012] In general, polyolefins, poly-α-olefins, their copolymers and/or their polymer blends have good chemical resistance and require high temperature (above 100° C. except poly(α-methyl styrene)) to prepare the clear solutions. Solutions turbid at lower temperature eventually form a gel.
BRIEF DESCRIPTION OF FIGURES
[0013] FIG. 1 shows a field-emission scanning electron microscope (FE-SEM) image of an electrospun polypropylene fiber membrane from cyclohexane, acetone and DMF (80/10/10 w/w/w/—weight %) according to example 1 at ×500 magnification.
[0014] FIG. 2 shows a field-emission scanning electron microscope (FE-SEM) image of an electrospun poly(1-butene) fiber membrane from cyclohexane, acetone and DMF (80/10/10 w/w/w/—weight %) according to example 1 at ×250 magnification.
[0015] FIG. 3 shows a field-emission scanning electron microscope (FE-SEM) image of an electrospun poly(4-methyl-1-pentene) fiber membrane from cyclohexane, acetone and DMF (80/10/10 w/w/w/—weight %) according to example 1 at ×1000 magnification.
[0016] FIG. 4 contains the schematic diagram of electrospinning results and FE-SEM images of as-spun PMP fibers from solutions of PMP in (A) cyclohexane, (B) a mixture of cyclohexane and acetone (80/20, w/w—weight percent)), (C) a mixture of cyclohexane and DMF (80/20, w/w—weight %) and (D)) a mixture of cyclohexane, acetone and DMF (80/10/10, w/w/w—weight %). The arrows in FIG. 4C illustrated curled and/or twisted fibers structures.
[0017] FIG. 5 shows field-emission scanning electron microscope (FE-SEM) images of an electrospun fiber membranes of blends (PB/PMP) from cyclohexane, acetone and DMF (80/10/10 w/w/w/—weight %) according to example 1 at ×500 magnification, (A) PB/PMP (75/25), (B) PB/PMP (50/50) and PB/PMP (25/75).
[0018] FIG. 6 is a schematic of an electrospinning process with continuous supplying system.
DETAILED DESCRIPTION OF THE INVENTION
[0019] According to the invention, polyolefin polymers are completely dissolved in a multi-component solvent system to form a clear solution when heated preferably to 50° C.-100° C. depending on the solvent type, the polymer type and the molecular weight. Cooling the polymer solutions slowly under ambient conditions to 25° C.-50° C. depending on the solvent type, the polymer type and polymer concentration results in clear solutions for electrospinning. Tailoring the multi-component solvent system with a blend of solvent and non-solvent for the specific polyolefin class polymer allows for a disruption of chain-chain interactions yielding a clear solution for electrospinning at room temperature in polypropylene, polybutene, and poly (4-methyl-1-pentene), etc. systems. This is a novel result never before obtained. All other work on electrospinning of polypropylene, polybutene, and poly(4-methyl-1-pentene),etc systems has been performed in melt electrospinning without the presence of solvent.
[0020] The invention has potential applications in filtration of liquids, gases and molecular filters. Reinforcement of composite materials, protective clothing, protective masks, biomedical application such as medical prostheses, tissue engineering templates, wound dressing, drug delivery systems, and pharmaceutical compositions, cosmetic skin care and cleaning etc. are additional applications.
[0021] Clear solutions, an indicator that gelation has not occurred in polyolefins, poly-α-olefins, their copolymers and/or polymer blends, can be obtained by dissolving the polymer in a good solvent and/or in a mixture of solvent and non-solvents at room temperature up to to temperatures at which the solvents boil depending on the polymer concentration, molecular weight and polymer type. When the clear solutions were lowered to room temperature (25° C.), these solutions remained clear for a certain time.
[0022] The fibers are made from a polymer solution by an electrospinning process as described in Reneker, U.S. Pat. No. 4,323,525, U.S. Pat. No. 4,689,525, US 20030195611, US 20040018226, and US 20010045547, which are incorporated herein by reference in their entirety for all useful purposes.
[0023] The polymers that are preferably used are listed in Huang, US 20030195611, US 20040037813, US 20040038014, US 20040018226, US20040013873, US 2003021792, US 20030215624, US 20030195611, U S 20030168756, US 20030106294, US 20020175449, US20020100725, US20020084178 and also in the following U.S publications, US 20020046656, US 20040187454, US 20040123572, US 20040060269, US 20040060268 and US 20030106294. All these publications are all incorporated by reference in their entireties for all useful purposes.
[0024] The preferred solvents that may be used are (a) a high-volatility solvent group, including acetone, chloroform, ethanol, isopropanol, methanol, toluene, tetrahydrofuran, water, benzene, benzyl alcohol, 1,4-dioxane, propanol, carbon tetrachloride, cyclohexane, cyclohexanone, methylene chloride, dichloromethane, phenol, pyridine, trichloroethane, acetic acid; or
[0025] (b) a relatively low-volatile solvent group, including N,N-dimethyl formamide (DMF), dimethyl sulfoxide (DMSO), N,N-dimethylacetamide (DMAc), 1-methyl-2-pyrrolidone (NMP), ethylene carbonate (EC), propylene carbonate (PC), dimethyl carbonate (DMC), acetonitrile (AN), N-methylmorpholine-N-oxide, butylene carbonate (BC), 1,4-butyrolactone (BL), diethyl carbonate (DEC), diethylether (DEE), 1,2-dimethoxyethane (DME), 1,3-dimethyl-2-imidazolidinone (DMI), 1,3-dioxolane (DOL), ethyl methyl carbonate (EMC), methyl formate (MF), 3-methyloxazolidin-2-on (MO), methyl propionate (MP), 2-methyletetrahydrofurane (MeTHF) or sulpholane (SL). Other solvents that can be used are listed in US20020100725 and US20030195611, which are incorporated by reference. The amount of polymer and solvent will vary from 0.1-99.9%, the latter being a highly concentrated polymer solution. In general, it has been shown that polymers can be electrospun when their concentration in solution, C, multiplied by the intrinsic viscosity of the solution, η, is ≧8.9 (M. G. McKee, G. L. Wilkes R. L. Colby and T. E. Long, Macromolecules 2004, 37, 1760 (“McKee”).
[0026] The concentration of polymer and solvent can be the same as discussed in the electrospinning publications and patents, Reneker, Megelski, Casper, U.S. Pat. No. 4,323,525, U.S. Pat. No. 4,689,525, US 20030195611, US 20040018226 and US 20010045547, which are all incorporated herein by reference in their entirety for all useful purposes.
[0027] Electrospinning or electrostatic spinning is a process for creating fine polymer fibers using an electrically charged solution that is driven from a source to a target with an electrical field. Using an electric field to draw the positively charged solution results in a jet of solution from the orifice of the source container to the grounded target. The jet forms a cone shape, called a Taylor cone, as it travels from the orifice. Typically, as the distance from the orifice increases, the cone becomes stretched until, near the target, the jet splits or splays into many fibers prior to reaching the target. Also prior to reaching the target, and depending on many variables, including target distance, charge, solution viscosity, temperature, solvent volatility, polymer flow rate, and others, the fibers begin to dry. These fibers are extremely thin, typically measured in nanometers. The collection of these fibers on the target, assuming the solution is controlled to ensure the fibers are still wet enough to adhere to each other when reaching the target, form a randomly oriented fibrous material with extremely high porosity and surface area, and a very small average pore size.
[0028] The basic components required for solvent electrospinning are as follows A polymer is mixed with a solvent to form a solution having desired qualities. The solution is loaded into a syringe like container that is fluidly connected to a blunt needle to form a spinneret. The needle has a distal opening through which the solution is ejected by a controlled force, represented here in a simplified manner as being supplied by a plunger but can be any appropriate controllable variable rate fluid displacement system and should be automated to ensure accurate flow rates.
[0029] The electrospinning process is carried out at temperatures ranging from a lower limit at which the solvent freezes to an upper limit where the solvent evaporates or the polymer degrades chemically.
EXAMPLES
Example 1
[0030] As a result of electrospinning the polyolefin solutions, fibers whose diameters range between 1 and 10 microns are produced depending on the concentration of polyolefin in the mixed solvent system. Under other conditions, fibers smaller and bigger than this range have been produced by the electrospinning process as described in Megelski, “Stephens” (J. S. Stephens, J. F. Rabolt, S. Fahnestock and D. B. Chase, MRS Proceedings 774, 31(2003)), US20030195611 and US20030168756 which are incorporated by reference.
[0031] The as-produced fibers have been studied using both optical and field emission scanning electron microscopy (FE-SEM) in order to ascertain any surface topography that may exist and to determine the presence of any morphological defects.
Example 2
[0032] Poly(4-methyl-1-pentene) (PMP) is a widely used polymer in industry and specifically, in medical products. Producing micro- or nanofiber membranes would expand the usefulness of PMP to a broaden range of medical applications. A choice of solvent quality for the solution used for electrospinning can have a dramatic effect on the spinnability of fibers and on their morphological appearance. We tested the following four solvent systems: cyclohexane, cyclohexane/acetone mixture, cyclohexane/dimethyl formamide (DMF) mixture and cyclohexane/acetone/DMF mixture. As demonstrated by FE-SEM, electrospun fibers with different morphologies including round, twisted with a roughened texture, curled and twisted-ribbon shapes were formed. The fiber shape and morphology depended strongly on the type and amount of non-solvent used.
[0033] Each PMP solution was poured into a 3-ml syringe equipped with a 21 gauge needle (Hamilton). A high-voltage power supply (Gassman High Voltage) capable of generating voltages up to 30 kV was used to generate a 10-15 kV potential difference between the needle and a grounded metallic plate with Al-foil placed 15 cm from the tip of the needle. All fiber spinning was carried out at ambient conditions. A schematic of the electrospinning apparatus is shown in the FIG. 6 .
[0034] The morphologies of electrospun PMP fiber membranes were investigated using field emission scanning electron microscopy (FE-SEM, JSM-7400F, JEOL). Typical imaging conditions were 1-2 kV and 10 μA. Depending on the mixture of solvents and nonsolvents or poor solvents used a distinctly different fiber morphology as shown in FIG. 4 was obtained.
Example 3
[0035] If a blend of two or more polyolefins is dissolved in the mixed solvent system described above then blended polymer fibers can be electrospun using the typical conditions mentioned previously. For example, PB/PMP blended fibrous mats can be produced in this way. FIG. 5 shows field-emission scanning electron microscope (FE-SEM) images of an electrospun fiber membrane of blends (PB/PMP) from cyclohexane, acetone and DMF (80/10/10 w/w/w/—weight %) according to Example 1 at ×500 magnification, (A) PB/PMP (75/25), (B) PB/PMP (50/50) and PB/PMP (25/75). In all cases, twisted flat fibers are produced.
[0036] All the references described above are incorporated by reference in its entirety for all useful purposes.
[0037] While there is shown and described certain specific structures embodying the invention, it will be manifest to those skilled in the art that various modifications and rearrangements of the parts may be made without departing from the spirit and scope of the underlying inventive concept and that the same is not limited to the particular forms herein shown and described. | A process to make a polyolefin fiber which has the following steps: mixing at least one polyolefin into a solution at room temperature or a slightly elevated temperature to form a polymer solution and electrospinning at room temperature said polymer solution to form a fiber. | 3 |
BACKGROUND OF THE PRIOR ART
This invention relates to devices arranged to loosen the twisted strands of a length of cable and secure the loosened cable in a stationary position while the length of cable is being spliced, and more particularly, this invention provides a portable cable splicing vise stand which is configured to permit one man to accomplish a cable splice without assistance even in remote areas such as logging fields.
Although some cable splicing vises have been known in the art, such as those disclosed in U.S. Pat. Nos. 2,724,986 and 826,766, no device have been known heretofore in the art which secures a length of cable and provides means by which the cable may be easily untwisted in order to permit a conventional cable splice to be undertaken.
It has heretofore been conventional, in a logging field for example, for a cable splice to be accomplished by spiking a cable to a log or stump with railroad spikes, and driving a marlin spike through the cable between the strands in order to open spaces in the intermediate portion of the cable so that a person can "weave" cable strands between the openings in portion of the cable. One can certainly appreciate the difficulty in the foregoing operation when one considers the effort required to accomplish this operation with a tightly woven cable of an inch or 11/2 larger in diameter, with each individual strand being 3/8ths inch or more in diameter. Heretofore in the art, nothing known to the applicant has been provided which substitutes for or assists with the foregoing splicing operation in the field.
SUMMARY OF THE INVENTION
In its basic concept, this invention provides a cable splicing stand configured to securely engage a length of cable with vises at two spaced apart points along the cable, at least one vise being lockably rotatable whereby, by rotating the cable securing vise, the cable may be untwisted between its points of attachment on the stand, and thereby opening up spaces between the cable strands to permit separate, individual cable strands to be woven therethrough to form a finished splice once the conventional weaving process is completed and the cable is again released from the stand.
It is by virtue of the foregoing basic concept that the principal objective of this invention is achieved; namely, the provision of a stand which supports a cable in a convenient position for a splice to be made, and further, a stand which also accomplishes the opening up of spaces between the strands of a cable so that additional strands may be easily inserted therebetween during weaving, the entire operation being easily accomplishable by one individual.
Another object and advantage of this invention is the provision of a cable splicing stand of the class described which is configured to be usable in remote areas such as logging fields and the like where heretofore no such apparatus has been available.
Still another object and advantage of this invention is the provision of a cable splicing stand of the class described which may be supported for use in a variety of convenient ways for versatility of use, such ways including freestanding on a ground surface, straddling fallen logs, and attached to a vehicle by a conventional trailer hitch.
Yet another object and advantage of this invention is the provision of a cable splicing stand of the class described in which the length of the splicing portion of a cable between the spaced apart points of engagement by vises can be easily varied for different types and diameters of cable to be spliced.
A further object and advantage of this invention is the provision of a cable splicing stand of the class described which is collapsible for convenient storage and handling.
A still further object and advantage of this invention is a cable splicing stand of the class described which is of simplified construction for economical manufacture.
The foregoing and other objects and advantages of this invention will appear from the following detailed description, taken in connection with the accompanying drawings of a preferred embodiment.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side elevation of a portable cable splicing stand embodying the features of this invention, the drawing illustrating two alternative mounting means by which the stand is supported over a ground surface.
FIG. 2 is a plan view of the cable splicing stand as viewed from the top in FIG. 1.
FIG. 3 is a an end view of the cable splicing stand as viewed from the right in FIG. 1, the view illustrating alternative ways that the leg structure may be utilized to support the stand above a ground surface, either by disposition on a ground surface or by straddling a fallen tree trunk.
FIG. 4 is a fragmentary end view of the rotatable vise assembly taken along the line 4--4 in FIG. 1.
FIG. 5 is a fragmentary sectional view of the vise-mounting rotating plate assembly, taken along the line 5--5 in FIG. 2.
FIG. 6 is a fragmentary, sectional view of the rear cable support structure taken along the line 6--6 in FIG. 1.
DESCRIPTION OF THE PREFERRED EMBODIMENT
FIGS. 1, 2 and 3 of the drawings show respective side, plan and end views of a preferred embodiment of a cable splicing vise stand embodying the features of this invention, and together thus illustrate the overall basic concept of this invention. As is seen, the stand includes a base frame assembly 10 which comprises, in this embodiment, a first base member 12 formed of a length of box steel. The outer terminal end of the base member 12 mounts an upstanding end member 14.
A second base member 16, formed of box steel having a hollow interior dimensioned sufficiently to receive the first base member telescopically therein, mounts a second upstanding end member 18. Clamp means, illustrated herein as set screw 20, is provided, as is conventional, to frictionally secure the two base sections 12, 16 together in a desired position of longitudinal extension.
Means is provided to support the frame securely above a ground surface. In the embodiment illustrated, two alternative support means are shown. The first, seen in FIG. 1, shows the frame section 16 removably received within a standard box-channel trailer hitch 22 shown in broken lines. Such hitches are common on pickup trucks and the like, and typically include a pin 24 arranged to be received through aligned bores in the hitch members to releasably secure the hitch and the frame member 16 together.
Another means to support the frame above a ground surface is also shown in FIG. 1, as well as in FIGS. 2 and 3. In this version, front and rear upstanding leg members 26, 28 are provided on the frame sections 12, 16 to support the frame securely above the ground for use. As seen, each leg member may be configured as an inverted "V", secured at its closed end to a box channel 30, 32 configured to receive the frame base members 12, 16 respectively. Friction clamp screws 34 provided on the box channels 30, 32 releasably secure the assemblies in desired position on their respective frame base members. In this manner, the leg members may be removed for convenience when the stand is not in use.
The leg members 26, 28 preferably are configured with a foot member 26' 28' arranged to be supported by a ground surface, and may include bores 36 therethrough whereby spikes 38, bolts, screws or the like may be used to secure the legs positively to a ground surface if such a secure and immovable support is required. Out in the field, such as in logging, such floor surfaces aren't available, so the leg members 26, 28 are preferably configured to straddle fallen tree trunks T and the like. If it is necessary to secure the frame in place, spikes 38 may be provided, as shown in FIG. 3, to securely anchor the assembly in position.
It will be appreciated by those skilled in the art that, although FIG. 1 shows the frame 10 mounting leg members 26, 28 while also engaging a trailer hitch 22, these are merely illustrative of alternative support means, and only one such version would be employed at a time. For example, if the stand is secured to the hitch of a truck or other vehicle, the leg members 26, 28 would not be installed on the base frame members 12, 16.
Similarly, although FIG. 3 shows that the legs are being supported both on a log F and on a ground surface G, these are illustrative only, and in use, the legs would be engaging either a ground surface or a tree trunk as the circumstances dictate.
As illustrated, the stand mounts at the upper terminal ends of the front and rear upstanding end members 14, 18, means to receive and secure a length of cable C to be spliced. Referring to the assembly associated with the rear end member 18, a vise-mounting base member 40 is secured to the end member 18 and is configured to mount, in the preferred embodiment, a conventional chain-type pipe vise 42 seen best in FIGS. 1 and 2. Although other types of vises and clamps will work adequately to secure a cable immovably on the stand, the chain-type vise common in plumbing has been found to be the most versatile and convenient for this use.
It is desirable, although not essential, that means be provided to confine a cable in the area adjacent the vise 42, particularly when splices are being done in order to form closed loop ends as is illustrated clearly in FIG. 2. With it understood that these cables may be two inches or more in diameter, it becomes apparent to those skilled in the art that the handling and management of the cable, while also engaging, clamping and operating the vise, can be tedious and rather difficult due to the awkwardness and inherent tension of these large cables.
In this regard, the preferred embodiment of the stand of this invention includes a releasable cable-confining bail assembly disposed rearward of the vise 42. As illustrated in FIGS. 1, 2 and 6, the vise-mounting base member 40 mounts, by pivot hinge 44, an inverted U-shaped bail member 46 configured to pivotally overlie the base member 40 and, together with the base member 40, releasably define a confined area through which the cable may pass, as seen clearly in FIGS. 2 and 6. Cooperating flanges 48, 50 on the base member 40 and the bail 46 respectively include bores (not shown) therethrough which align when the ball is in the closed position shown to releasably receive the lock pin 52 for releasably securing the bail in operative, closed condition.
In order to further ease the proper alignment of the cable preliminary to its engagement by the chain vise, a table saddle 54 may be provided, as shown, to support the cable in proper elevational position relative to the vise.
The forward upstanding end member 14 also mounts means to receive and secure a length of cable to be spliced. In this regard, a vise-supporting base plate 56 is secured to the upper end of the end member 14. As illustrated, the base plate in the preferred embodiment may be configured substantially as a square or rectangular plate mounted for disposition in the upstanding condition shown. The base plate is provided with an elongated slot 58 extending, in the illustrated example, from its upper edge through its middle point. The slot is dimensioned to be at least as wide as the largest diameter of cable that will be served by the splicing stand.
A second, smaller, substantially circular plate member 60 is rotatably mounted on the base plate 56. In the embodiment illustrated, the base plate 56 mounts projecting "L" flanges 62 which define a space in which the circular plate 60 is freely received for rotational movement.
As illustrated best in FIGS. 4 and 5, the circular plate also includes an elongated slot 64 extending, similar to the slot 58 in the base plate 56, from the outside edge through the middle point, the slot being dimensioned to be at least as wide as the largest diameter of cable that will be serviced by the splicing stand.
Means is provided to selectively and releasably secure the second plate 60 against rotation. A greatly simplified version of locking means is shown in the drawings, but it is to be understood that it is merely illustrative, and other suitable locking means are contemplated as well.
In this embodiment, the outer peripheral wall of the circular plate 60 is configured with notched portions which provide abutment stops 66 (FIG. 5) for a locking bar 68 which is mounted by pivot 70 to the base plate 56. As is apparent, gravity encourages the working end 68' of the bar 68 downward against the outer peripheral edge of the plate 60, e.g. clockwise in FIG. 5, allowing the plate to rotate in one direction, but providing an abutment stop 66 against rotation in the reverse direction. When the working end of the bar drops into one of the notches and engages the confronting edge 66 of that notch, the result is substantially a ratchet effect in which the notched plate is a ratchet wheel and the locking bar is a pawl. Depressing the opposite end of the bar 68 pivots it about the axis of its pivot 70 and removes the working end from engagement in the notched portion of the circular plate, thereby allowing the plate 60 to rotate freely in the opposite (counterclockwise in FIG. 5) direction.
It will be apparent to those skilled in the art that the ratchet assembly just described could also alternatively be configured to permit selective locking in either or both directions of rotation of the plate if so desired. As has been discussed earlier, the stand of this invention is illustrated in its most basic working form so as not to unduly complicate the description and drawings, and so as not to detract from the importance of the invention as a whole.
As is seen most clearly in FIGS. 1 and 5, the circular plate 60 mounts, adjacent the bottom terminal end of the slot 64, a perpendicularly projecting base member 72 which securely mounts a chain-type vise 74 similar to the vise 42 previously described. The vise is mounted on the base member 72 which in turn is mounted on the rotating plate 60 so that the working clamp portion of the vise is disposed substantially on the line that extends through the center of rotation of the plate 60. That line also extends centrally through the corresponding slots 58, 64 and through the working clamp portion of the first vise 42 on the rear end member, as seen in FIGS. 1 , 2, 4 and 5.
Means is provided to facilitate rotation of the vise-mounting structure just described against the inherent tension of the cable secured by the vises 42, 74. In the simplified construction embodied herein, tubular or squared brackets 76 are mounted on the vise-mounting base member 72 and preferably disposed thereon in perpendicularly extending relationship relative to one another. The brackets 76 removably receive an elongated bar 78 which may be grasped by a person, the bar being of sufficient length as to afford the operator an adequate amount of leverage to rotate the assembly against the tension of a cable to untwist a cable into a loosened condition in which the individual cable strands are easily separated, as is clearly illustrated in FIGS. 1 and 2.
Having thus described the basic structure of the present invention, the operation of the preferred embodiment illustrated is as follows:
If it is convenient for the stand to be supported by a trailer hitch, the rear section of the stand being carried by the second base member 16 is installed first by sliding the terminal end of the base member 16 into the box trailer hitch 22, where it may be secured in place by the conventional hitch retaining pin 24. The forward stand section is installed by sliding the first base member 12 into the hollow confines of the base member 16 until a desired working distance between the front and rear cable clamp assemblies is obtained, whereupon the friction clamp 20 is tightened to positively secure the base members 12 and 16 together in that position. The distance between the cable clamp assemblies is adjusted as desired depending upon the thickness and type of cable being used. The thicker the cable, the greater the distance between clamp assemblies. The cable splicing stand is thus ready for use.
If it is desired or necessary that the stand be supported independently on its own leg members, the setup of the stand simply involves first sliding the leg member assembly 26, 30 onto the base member 12 and securing it in position by tightening clamp bolt 34 and then inserting the terminal end of the frame section 12 into the confines of the base member 16 and tightening clamp bolt 20 as described before, and finally connecting the other leg member assembly 28, 32 and clamping it in position by friction clamp 34. The stand is thus ready for use.
In situations where the ground may be particularly uneven or unsteady, or in situations where the stand might become unsteady when a cable strand is being pulled through the cable in splicing, the leg members may be spiked to a fallen tree or the like as seen in FIG. 3. Similarly, the legs may be bolted to a floor or staked to the ground for the same reasons if so needed.
With regard now to the actual use of the cable splicing stand of this invention, reference is first had to FIGS. 2 and 4 of the drawings. In proper initial condition before a cable is installed, the rotating plate member 60 is in the position shown in FIG. 4 in which the respective slots 58, 64 in the base plate 56 and the rotating plate 60 are aligned. The ratchet lock bar 68 is pivoted fully so as to clear the aligned slots, and a cable length is lain into the slot, the cable being drawn rearwardly through the rear bail assembly 46, whereupon the terminal end of the cable is then brought back through the bail assembly in the reverse direction as is clearly seen in FIG. 2. The cable thus forms a loop by virtue of the confining bail assembly which also retains the terminal end of the cable in the forwardly extending position shown. The chain 42' of the vise 42 is drawn around the cable as shown, and the vise operated to securely clamp the two diameters of cable tightly. The chain 74' of the front vise 74 is drawn around the cable and the vise operated to securely engage the single diameter of cable as shown.
The operator then rotates the front vise mounting assembly as has been described earlier. Because the cable is securely and immovably clamped by the vise 74 which is rotated in the direction opposite the wrappings of the cable, the cable is untwisted between the two vise members 42, 74 and gaps are thus opened between the individual strands of the cable. The ratchet mechanism prevents the assembly from inadvertently rotating in the reverse direction due to the significant inherent tension of the cable. Once the cable has been untwisted to a desired degree, typically about one revolution, the operator then simply unravels the cable strands from the terminal end of the cable that is not engaged by the rotating vise, and begins to simply weave the individual strands through the open spaces in the untwisted portion of the cable in the manner that is dictated by the particular type of splice that is being done. If desired, a conventional marlin spike can easily be inserted by hand through the spaces between the wound cable strands first to open up the desired space more broadly for easier passage of the cable strand end therethrough. But as understood, the spike no longer needs to be driven or hammered through the cable since it has already been untwisted.
As more and more strands are woven into the spaces in the intermediate unwound portion of the cable, less and less space becomes available, and the operator need only go back and rotate the cab le further to open up more spaces as he continues the splicing operation. Once the splice has been fully accomplished, the operator operates the ratchet assembly to allow the rotating vise assembly to turn in the opposite direction until the cable has returned to its normal condition of inherent tension. The splice is thus complete.
The chain vises are released, the bail assembly is opened so that it no longer retains the cable, and the cable, which now has a closed loop end in this example, is simply lifted out and the entire operation is complete. The foregoing splicing operation has just been described in connection with one person doing the entire job without the necessity of using brute strength, other workers assisting to untwist and hold the cable, the need of forceably driving spikes through the strands to open up individual spaces through which cable strands may be laboriously drawn through, or any of the other heretofore conventional and energy and time consuming exercises that have previously been required to accomplish cable splices in the field. Also eliminated are the common hazards of injuries resulting from the forced manipulation of tensioned cables with spikes and hammers, the slipping of spikes, and other common occurrences.
From the foregoing it will be apparent to those skilled in the art that various changes other than those already described may be made in the size, shape, type, number and arrangement of parts described hereinbefore without departing from the spirit of this invention and the scope of the appended claims. For example, as mentioned earlier the ratchet assembly shown is merely illustrative of one means to secure the assembly against rotation resulting from the inherent tension of the cable. Also, although the rotating vise assembly is shown in connection with one end of the stand, it could alternatively be provided as well on the opposite end if so desired. Moreover, it is to be understood that both vise assemblies could be configured for releasable rotation in order to minimize the amount of rotation required of just one assembly or for accomplishing different types of cable splicing than the closed loop type of splice illustrated herein. Additionally, various alternative drive arrangements could be provided if so desired as an alternative to the manual bar 78 arrangement shown herein for simplicity. | A portable cable splicing stand comprises a longitudinally elongated base frame arranged to be supported above a ground surface as by removable leg members. A pair of adjustably spaced apart upright members extend vertically from the base frame, and each supports a chain vise arranged to receive and clamp between them a desired length of cable to be spliced. One of the chain vises is mounted on the frame for rotation about the axis of the cable so that with a cable clamped by the vises, rotation of the one vise in the direction opposite the windings of the cable untwists the cable between the vises and opens spaces between the individual strands so that the terminal ends of individual cable strands may be woven therethrough easily and without significant effort. A ratchet assembly engages the rotatable vise mount to releasably lock the assembly against reverse rotation of the vise when the cable is in tensioned condition. A bale assembly is provided adjacent the non-rotating vise to assist in confining a length of cable and maintaining it in a position closely adjacent the chain vise to facilitate handling of the cable while engaging the vise particularly in forming closed loop end splices with large diameter cables. | 3 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of PCT International Patent Application No. PCT/EP2003/050290, filed on Jul. 8, 2003, designating the United States of America, and published, in English, as PCT International Publication No. WO 2004/005541 A1 on Jan. 15, 2004, which claims the benefit under 35 U.S.C. § 119 of European Patent Application Serial No. 03076033.4, filed Apr. 8, 2003 and European Patent Application Serial No. 02077724.9, filed Jul. 9, 2002, the entirety of each of which is incorporated by reference.
STATEMENT ACCORDING TO 37 C.F.R. § 1.52(e)(5)—SEQUENCE LISTING SUBMITTED ON COMPACT DISC
[0002] Pursuant to 37 C.F.R. § 1.52(e)(1)(iii), a compact disc containing an electronic version of the Sequence Listing has been submitted concomitant with this application, the contents of which are hereby incorporated by reference. A second compact disc is submitted and is an identical copy of the first compact disc. The discs are labeled “copy 1” and “copy 2,” respectively, and each disc contains one file entitled “V121.ST25.txt” which is 76 KB and created on Jan. 10, 2005.
TECHNICAL FIELD
[0003] The present invention relates generally to the field of human genetics. Specifically, the present invention relates to methods and materials used to isolate and detect human peripheral neuropathy causing or predisposing genes, some alleles of which cause peripheral neuropathy.
BACKGROUND OF THE INVENTION
[0004] Peripheral neuropathy is a common neurological disorder resulting from damage to the peripheral nerves. It may be acquired and caused by diseases of the nerves or as the result of systemic illness. Many neuropathies have well-defined causes such as diabetes, uremia, AIDS, or nutritional deficiencies. In fact, diabetes is one of the most common causes of peripheral neuropathy. Other causes include mechanical pressure such as compression or entrapment, direct trauma, penetrating injuries, contusions, fracture of dislocated bones, pressure involving the superficial nerves (ulnar, radial, or peroneal), which can result from prolonged use of crutches or staying in one position for too long, or from a tumor, intraneural hemorrhage, exposure to cold or radiation or, rarely, certain medicines or toxic substances, and vascular or collagen disorders, such as atherosclerosis, systemic lupus erythematosus, scleroderma, sarcoidosis, rheumatoid arthritis, and polyarteritis nodosa. In addition, hereditary peripheral neuropathies, among the most common genetic disorders in humans, are a complex, clinically and genetically heterogeneous group of disorders and they produce progressive deterioration of the peripheral nerves. This group of disorders includes hereditary motor and sensory neuropathies (HMSN), hereditary motor neuropathies (HMN) and hereditary sensory neuropathies (HSN). Our understanding of these disorders has progressed from the description of the clinical phenotypes and delineation of the electrophysiologic and pathologic features to the identification of disease genes and elucidation of the underlying molecular mechanisms. Charcot-Marie-Tooth (CMT) disease is the most common inherited disorder of the peripheral nervous system (PNS), with an estimated frequency of 1/2500 individuals. CMT can be divided into two distinct groups based on electrophysiologic studies. CMT type 1 (CMT1) exhibits moderately to severely reduced motor nerve velocity conduction (NCV). The conduction deficit in CMT1 is bilaterally symmetric, which suggests an intrinsic Schwann cell defect. In contrast, CMT type 2 (CMT2) results from neuronal atrophy and degeneration and exhibits normal or only mildly reduced NCV with decreased amplitudes. Recent molecular analysis of the inherited peripheral neuropathies (IPN) has led to important insights into the process of myelination and the function of some of the genes involved. An important problem for the physician is that the IPN show considerable clinical and genetical heterogeneity. 1 The discovery that mutations in multiple genes result in similar phenotypes argues for complex protein interactions and complementing functions for each protein product within the myelin sheath. Knowledge of the structure and function of the causal genes is currently being actively pursued to better classify peripheral neuropathies and to elucidate the underlying molecular mechanisms of these diseases. Thus, the knowledge of the exact genetic aberration in the patients has important ramifications for diagnosis, prognosis, genetic counseling, and approaches for therapy. In the present invention, missense mutations in the small GTPase RAB7 (SEQ ID NOS:169 and 170) and the guanine exchange factor ARHGEF10 (SEQ ID NOS:171 and 172) associated with peripheral neuropathy have been identified. The present invention can be used for the manufacture of a diagnostic assay for a more correct diagnosis of peripheral neuropathies.
SUMMARY OF THE INVENTION
[0005] The present invention relates generally to the field of human genetics. Specifically, the present invention relates to methods and materials used to isolate and detect human peripheral neuropathy causing or predisposing genes (RAB7 and ARHGEF10), some alleles of which cause peripheral neuropathy. In particular, alleles of RAB7 cause Charcot-Marie-Tooth type 2B (CMT2B). Charcot-Marie-Tooth type 2B (CMT2B) (MIM # 600882) or hereditary motor and sensory neuropathy type IIB (HMSN IIB) is clinically characterized by marked distal muscle weakness and wasting, a high frequency of foot ulcers, infections and amputations of the toes due to recurrent infections. 2 More specifically, the present invention relates to germ line mutations in the RAB7 gene (SEQ ID NO:169) and/or the ARHGEF10 gene (SEQ ID NO:171) and their use in the diagnosis of peripheral neuropathy.
[0006] The Rho (Ras homology) proteins have been shown to regulate intracellular signaling activities including organization of the actin cytoskeleton, vesicular trafficking, extension of cellular processes and transcriptional regulation of gene expression. Several studies have demonstrated that the growth cone, by which neurons extend their axons and dendrites towards appropriate targets, is guided by extracellular signals and is transduced via Rho GTPases. The Rho GTPases couple intracellular signal transduction pathways to changes in the external environment. The GTPase has an inactive (GDP-bound) and active (GTP-bound) conformation. Guanine exchange factor proteins (GEFs), such as ARHGEF10, catalyze the release of GDP allowing GTP to bind. In the active GTP-bound state, Rho GTPases interact with target proteins to activate a cellular response. An intrinsic GTPase activity, catalyzed further by GTPase-activating proteins (GAPs), completes the cycle and the GTPase returns to an inactive GDP-bound state. RAB7 belongs to the Rab family of Ras-related GTPases. These Rab proteins are essential for the regulation of intracellular membrane trafficking. The Rab proteins regulate vesicular transport through the recruitment of specific effector or motor proteins and may have a role in linking vesicles and target membranes to the cytoskeleton. 10, 11
[0007] To date, about 60 human RAB genes have been identified and the majority is likely to control highly specialized functions in many cell types. Mutations in RAB genes may cause a wide range of inherited diseases. 16 RAB7 is involved in the transport between late endosomes and lysosomes and recent studies demonstrate that the RAB7-effector protein RILP (RAB7 interacting lysosomal protein) induces the recruitment of dynein-dynactin motors and regulates transport toward the minus-end of microtubules. 12, 13 Expression of RAB7-dominant negative mutants in cells inhibits degradation and disperses lysosomes. One such mutant, RAB7N125I, is localized in the GTP-binding domain and proximal to Leu129Phe mutation in families CMT-140 and CMT-126 ( FIG. 1 , Panel C). In vitro studies demonstrated that this mutant RAB7N125I protein exists preferentially in a nucleotide-free form and has been shown to have a dominant negative effect on late endocytic transport. 14 In contrast, in cells overexpressing RAB7, late endocytic vesicles accumulated in the perinuclear region, probably due to an increased motility in the minus-end direction of microtubules. 15
[0008] Thus, the invention discloses methods for determining the presence or absence of RAB7 and/or ARHGEF10 mutations that are useful in the diagnosis or susceptibility to peripheral neuropathy and, more particularly, wherein RAB7 mutations are useful in the diagnosis or susceptibility to CMT2 and, even more particularly, to CMT2B. Mutations of RAB7 (SEQ ID NO:169) causing peripheral neuropathy and, more specifically, CMT2B are included in Table 1A. Mutations of ARHGEF10 (SEQ ID NO:171) causing peripheral neuropathy are included in Table 1B. The amino acid sequence of RAB7 is depicted in SEQ ID NO:170 and the amino acid sequence of ARHGEF10 is depicted in SEQ ID NO:172. These nucleic acids or fragments capable of specifically hybridizing with the corresponding allele in the presence of other RAB7 alleles and/or ARHGEF10 alleles under stringent conditions find broad diagnostic application. Gene products of the disclosed mutant RAB7 and/or ARHGEF10 alleles also find a broad range of diagnostic applications. For example, mutant allelic RAB7 peptides and/or mutant allelic ARHGEF10 peptides can be used to generate specific binding compounds. Binding reagents can be used diagnostically to distinguish wild-type and peripheral neuropathy, more particularly, CMT2B causing RAB7 translation products. The subject nucleic acids (including fragments thereof) may be single or double-stranded and are isolated, partially purified, and/or recombinant. An “isolated” nucleic acid is present as other than a naturally occurring chromosome or transcript in its natural state and isolated from (not joined in sequence to) at least one nucleotide with which it is normally associated on a natural chromosome; a partially pure nucleic acid constitutes at least about 10%, preferably at least about 30%, and more preferably at least about 90% by weight of total nucleic acid present in a given fraction; and a recombinant nucleic acid is joined in sequence to at least one nucleotide with which it is not normally associated on a natural chromosome.
[0009] In a first embodiment, the invention provides an isolated nucleic acid coding for a dominant negative, mutant RAB7 polypeptide and/or an isolated nucleic acid coding for a dominant negative, mutant ARHGEF10 polypeptide, the nucleic acid containing, in comparison to the wild-type RAB7 encoding sequence set forth in SEQ ID NO:169, one or more mutations and/or the nucleic acid containing, in comparison to the wild-type ARHGEF10 encoding sequence set forth in SEQ ID NO:171, one or more mutations, wherein the presence of the nucleic acids is indicative for a predisposition or the presence of a peripheral neuropathy.
[0010] In yet another embodiment, the invention provides an isolated nucleic acid coding for a dominant negative, mutant RAB7 polypeptide and/or an isolated nucleic acid coding for a dominant negative, mutant ARHGEF10 polypeptide, the nucleic acid containing, in comparison to the wild-type RAB7 encoding sequence set forth in SEQ ID NO:169, one or more mutations selected from the mutations set forth in Table 1A and/or the nucleic acid containing, in comparison to the wild-type ARHGEF10 encoding sequence set forth in SEQ ID NO:171, one or more mutations set forth in Table 1B, wherein the presence of the nucleic acids is indicative for a predisposition or the presence of a peripheral neuropathy.
[0011] “Mutant,” as used herein, refers to a gene that encodes a mutant protein. With respect to proteins, the term “mutant” means a protein that does not perform its usual or normal physiological role and that is associated with, or causative of, a pathogenic condition or state. Therefore, as used herein, the term “mutant” is essentially synonymous with the terms “dysfunctional,” “pathogenic,” “disease-causing,” and “deleterious.” With respect to the gene-encoding RAB7 protein and/or ARHGEF10 of the present invention, the term “mutant” refers to a gene encoding RAB7 and/or ARHGEF10, bearing one or more nucleotide/amino acid substitutions, insertions and/or deletions that, for example, can lead to the development of the symptoms of a peripheral neuropathy when expressed in humans. This definition is understood to include the various mutations that naturally exist, including, but not limited to, those disclosed herein, as well as synthetic or recombinant mutations produced by human intervention. The term “mutant,” as applied to the gene encoding RAB7 and/or ARHGEF10, is not intended to embrace sequence variants that, due to the degeneracy of the genetic code, encode proteins identical to the normal sequences disclosed or otherwise presented herein; nor is it intended to embrace sequence variants that, although they encode different proteins, encode proteins that are functionally equivalent to normal RAB7 and/or ARHGEF10. Assays to measure the activity of (mutant) Rab proteins are disclosed in WO 01/20022. These assays can, for example, be used to measure a possible dominant effect of the identified RAB7-mutations in peripheral neuropathy patients. A “dominant negative” allele or a “dominant negative” gene is a mutant allele or mutant gene that, when inherited, manifests the phenotype of the mutation, even in the presence of a wild-type allele or gene.
[0012] In another embodiment, the invention provides a nucleic acid probe wherein the nucleotide sequence is a fragment of a nucleic acid sequence derived from a dominant negative, mutant RAB7 gene and/or ARHGEF10 gene.
[0013] As used herein, “fragment” refers to a nucleotide sequence of at least about nine nucleotides, typically 15 to 75, or more, wherein the nucleotide sequence comprises at least one mutation for RAB7 and/or ARHGEF10.
[0014] In another embodiment, the isolated nucleic acids of the present invention include any of the above-described sequences or fragments of RAB7 and/or ARHGEF10 when included in vectors. Appropriate vectors include cloning vectors and expression vectors of all types, including plasmids, phagemids, cosmids, episomes, and the like, as well as integration vectors. The vectors may also include various marker genes (e.g., antibiotic resistance or susceptibility genes) that are useful in identifying cells successfully transformed therewith. In addition, the vectors may include regulatory sequences to which the nucleic acids of the invention are operably joined and/or may also include coding regions such that the nucleic acids of the invention, when appropriately ligated into the vector, are expressed as fusion proteins. Such vectors may also include vectors for use in yeast “two hybrid,” baculovirus, and phage-display systems. The vectors may be chosen to be useful for prokaryotic, eukaryotic or viral expression, as needed or desired for the particular application. For example, vaccinia virus vectors or simian virus vectors with the SV40 promoter (e.g., pSV2), or Herpes simplex virus or adeno-associated virus may be useful for transfection of mammalian cells including dorsal root ganglia or neurons in culture or in vivo and the baculovirus vectors may be used in transfecting insect cells. A great variety of different vectors are now commercially available and otherwise known in the art and the choice of an appropriate vector is within the ability and discretion of one of ordinary skill in the art.
[0015] In yet another embodiment, the invention provides a host cell comprising a recombinant vector according to the invention.
[0016] In yet another embodiment, the invention provides a method for the preparation of a diagnostic assay to detect the presence of a peripheral neuropathy in a human comprising detecting at least one mutation in the nucleotide position of SEQ ID NO:169 and/or SEQ ID NO:171 in a tissue sample of the human, wherein the mutation respectively results in a dominant mutation of RAB7 and/or a dominant mutation in ARHGEF10 and wherein the presence of the mutation is indicative of a predisposition or the presence of a peripheral neuropathy.
[0017] In yet another embodiment, the invention provides a diagnostic method for determining if a subject bears a mutant gene encoding RAB7 and/or ARHGEF10 comprising the steps of (1) providing a biological sample of the subject and (2) detecting in the sample a mutant nucleic acid encoding a RAB7 protein and/or ARHGEF10 or a mutant RAB7 protein activity and/or a mutant ARHGEF10 activity.
[0018] The RAB7 and/or ARHGEF10 gene and gene product, as well as other products derived thereof (e.g., probes, antibodies), can be useful in the diagnosis of peripheral neuropathy and probably also in acquired forms of peripheral neuropathy (in other words, to detect if a human has a predisposition to acquire a peripheral neuropathy or, more particularly, CMT2B in the case of RAB7). Diagnosis of, for example, inherited cases of these diseases can be accomplished by methods based upon the nucleic acids (including genomic and mRNA/cDNA sequences), proteins, and/or antibodies. Preferably, the methods and products are based upon the human RAB7 and/or ARHGEF10 gene, protein or antibodies against the RAB7 and/or ARHGEF10 protein. As will be obvious to one of ordinary skill in the art, however, the significant evolutionary conservation of large portions of RAB7 and/or ARHGEF10 nucleotide and amino acid sequences, even in species as diverse as humans and C. elegans and Drosophila, allow the skilled artisan to make use of such non-human RAB7- and/or ARHGEF10-homologue nucleic acids, proteins and antibodies, even for applications directed toward human or other mammalian subjects. Thus, for brevity of exposition, but without limiting the scope of the invention, the following description will focus upon uses of the human homologues of RAB7 and/or ARHGEF10 genes and proteins. It will be understood, however, that homologous sequences from other species will be equivalent for many purposes. As will be appreciated by one of ordinary skill in the art, the choice of diagnostic methods of the present invention will be influenced by the nature of the available biological samples to be tested and the nature of the information required. The RAB7 and/or ARHGEF10 gene is highly expressed in dorsal root ganglia (sensory neurons) and the ventral horn (motor neurons), but motor neuron biopsies are invasive, dangerous, difficult and expensive procedures, particularly for routine screening. Other tissues which express the RAB7 and/or ARHGEF10 gene at significant levels, however, may demonstrate alternative splicing (e.g., white blood cells) and, therefore, mRNA derived from the RAB7 gene or proteins from such cells may be less informative. Thus, assays based upon a subject's genomic DNA may be the preferred methods for diagnostics of the RAB7 and/or ARHGEF10 gene as no information will be lost due to alternative splicing and because essentially any nucleate cells may provide a usable sample. When the diagnostic assay is to be based upon nucleic acids from a sample, either mRNA or genomic DNA may be used. When mRNA is used from a sample, many of the same considerations apply with respect to source tissues and the possibility of alternative splicing. That is, there may be little or no expression of transcripts unless appropriate tissue sources are chosen or available, and alternative splicing may result in the loss of some information. With either mRNA or DNA, standard methods well known in the art may be used to detect the presence of a particular sequence, either in situ or in vitro (see, e.g. Genome Analysis, A laboratory Manual, eds E. D. Green, B. Birren, S. Klapholz, R. M. Myers, P. Hieter, Cold Spring Harbor Laboratory Press, 1997). In a preferred embodiment of the invention, the starting nucleic acid represents a sample of DNA isolated from an animal or human patient. This DNA may be obtained from any cell source or body fluid. Non-limiting examples of cell sources available in clinical practice include blood cells, buccal cells, cervico-vaginal cells, epithelial cells from urine, or any cells present in tissue obtained by biopsy. Body fluids include blood, urine, and cerebrospinal fluid. DNA is extracted from the cell source or body fluid using any of the numerous methods that are standard in the art. It will be understood that the particular method used to extract DNA will be chosen as being appropriate for the particular biological sample. For example, freeze-thaw and alkaline lysis procedures can be useful for obtaining nucleic acid molecules from solid materials; heat and alkaline lysis procedures can be useful for obtaining nucleic acid molecules from urine; and proteinase K extraction and/or phenol extractions can be used to obtain nucleic acid from cells or tissues, e.g., blood. In a specific embodiment, the cells may be directly used without purification of the target nucleic acid. For example, the cells can be suspended in hypotonic buffer and heated to about 90-100° C., until cell lysis and dispersion of intracellular components occur, generally about 1 to 15 minutes. After the heating step, the amplification reagents may be added directly to the lysed cells. This direct amplification method may, for example, be used on peripheral blood lymphocytes. The preferred amount of DNA to be extracted for analysis of human genomic DNA is at least 5 picograms (corresponding to about 1 cell equivalent of a genome size of 4×10 9 base pairs). In some applications, such as, for example, detection of sequence alterations in the genome of a microorganism, variable amounts of DNA may be extracted.
[0019] In a particular embodiment, the starting nucleic acid is RNA obtained, e.g., from a cell or tissue. RNA can be obtained from a cell or tissue according to various methods known in the art and described, e.g., Genome Analysis, A laboratory Manual, eds E. D. Green, B. Birren, S. Klapholz, R. M. Myers, P. Hieter, Cold Spring Harbor Laboratory Press, 1997. For in situ detection of a mutant nucleic acid sequence of RAB7 and/or ARHGEF10, a sample of tissue may be prepared by standard techniques and then contacted with a probe, preferably one which is labeled to facilitate detection, and an assay for nucleic acid hybridization is conducted under stringent conditions which permit hybridization only between the probe and highly or perfectly complementary sequences. In many applications, the nucleic acids are labeled with directly or indirectly detectable signals or means for amplifying a detectable signal. Examples include radiolabels, luminescent (e.g., fluorescent) tags, components of amplified tags, such as antigen-labeled antibody, biotin-avidin combinations, etc. The nucleic acids can be subject to purification, synthesis, modification, sequencing, recombination, incorporation into a variety of vectors, expression, transfection, administration or methods of use disclosed in standard manuals such as Genome Analysis, A laboratory Manual, eds E. D. Green, B. Birren, S. Klapholz, R. M. Myers, P. Hieter, Cold Spring Harbor Laboratory Press, 1997, or that are otherwise known in the art. Because many mutations in genes that cause diseases detected to date consist of a single nucleotide substitution, high stringency hybridization conditions will be required to distinguish normal sequences from most mutant sequences. A significant advantage of the use of either DNA or mRNA is the ability to amplify the amount of genetic material using the polymerase chain reaction (PCR), either alone (with genomic DNA) or in combination with reverse transcription (with mRNA to produce cDNA). Other nucleotide sequence amplification techniques may be used, such as ligation-mediated PCR, anchored PCR and enzymatic amplification as will be understood by those skilled in the art. Sequence alterations may also generate fortuitous restriction enzyme recognition sites which are revealed by the use of appropriate enzyme digestion followed by gel-blot hybridization. DNA fragments carrying the site (normal or mutant) are detected by their increase or reduction in size, or by the increase or decrease of corresponding restriction fragment numbers. Genomic DNA samples may also be amplified by PCR prior to treatment with the appropriate restriction enzyme and the fragments of different sizes are visualized, for example, under UV light in the presence of ethidium bromide, after gel electrophoresis. Genetic testing based on DNA sequence differences may be achieved by detection of alteration in electrophoretic mobility of DNA fragments in gels. Small sequence deletions and insertions can be visualized by high resolution gel electrophoresis of single-stranded DNA, or as changes in the migration pattern of DNA heteroduplexes in non-denaturing gel electrophoresis. Alternatively, a single base substitution mutation may be detected based on differential PCR product length in PCR. The PCR products of the normal and mutant gene may be differentially detected in acrylamide gels. Nuclease protection assays (S1 or ligase-mediated) also reveal sequence changes at specific locations or, alternatively, to confirm or detect a polymorphism resulting in restriction mapping changes. Ligated PCR, allele-specific oligonucleotide probes (ASOs), REF-SSCP chemical cleavage, endonuclease cleavage at mismatch sites or SSCP may be used. Both REF-SSCP and SSCP are mobility shift assays which are based upon the change in conformation due to mutations. DNA fragments may also be visualized by methods in which the individual DNA samples are not immobilized on membranes. The probe and target sequences may be in solution or the probe sequence may be immobilized. Autoradiography, radioactive decay, spectrophotometry and fluorometry may also be used to identify specific individual genotypes. Mutations in RAB7 and/or ARHGEF10 can also be detected by direct nucleotide sequencing. Methods for nucleotide sequencing are well known in the art. Fragments of the disclosed alleles of RAB7 and/or ARHGEF10 are sufficiently long for use as specific hybridization probes for detecting endogenous alleles and, particularly, to distinguish the disclosed mutant alleles which correlate with peripheral neuropathy, more particularly, CMT2B alleles in the use of RAB7. Preferred fragments are capable of hybridizing to the corresponding mutant allele under stringency conditions characterized by a specific hybridization buffer. In any event, the fragments are necessarily of length sufficient to be unique to the corresponding allele; i.e., has a nucleotide sequence at least long enough to define a novel oligonucleotide, usually at least about 14, 16, 18, 20, 22, or 24 bp in length, though such fragment may be joined in sequence to other nucleotides which may be nucleotides which naturally flank the fragment. For example, where the subject nucleic acids are used as PCR primers or hybridization probes, the subject primer or probe comprises an oligonucleotide complementary to a strand of the mutant or rare allele of length sufficient to selectively hybridize with the mutant or rare allele. Generally, these primers and probes comprise at least 16 bp to 24 bp complementary to the mutant or rare allele and may be as large as is convenient for the hybridization conditions. In some cases where the critical mutation in RAB7 and/or ARHGEF10 is a deletion of wild-type sequence, useful primers/probes require wild-type sequences flanking (both sides) the deletion with at least two, usually at least three, more usually at least four, most usually at least five, bases. Where the mutation is an insertion or substitution which exceeds about 20 bp, it is generally not necessary to include wild-type sequences in the probes/primers. For insertions or substitutions of fewer than 5 bp, preferred nucleic acid portions comprise and flank the substitution/insertion with at least two, preferably at least three, more preferably at least four, most preferably at least five, bases. For substitutions or insertions from about 5 to about 20 bp, it is usually necessary to include both the entire insertion/substitution and at least two, usually at least three, more usually at least four, most usually at least five, bases of wild-type sequence of at least one flank of the substitution/insertion.
[0020] The wording “stringent hybridization conditions” is a term of art understood by those of ordinary skill in the art. For any given nucleic acid sequence, stringent hybridization conditions are those conditions of temperature, chaotrophic salts, pH and ionic strength which will permit hybridization of that nucleic acid sequence to its complementary sequence and not to substantially different sequences. The exact conditions which constitute “stringent” conditions, depend upon the nature of the nucleic acid sequence, the length of the sequence, and the frequency of occurrence of subsets of that sequence within other non-identical sequences. By varying hybridization conditions from a level of stringency at which non-specific hybridization conditions occurs to a level at which only specific hybridization is observed, one of ordinary skill in the art can, without undue experimentation, determine conditions which will allow a given sequence to hybridize only with complementary sequences. Hybridization conditions, depending upon the length and commonality of a sequence, may include temperatures of 20° C.-65° C. and ionic strengths from 5× to 0.1×SSC. Highly stringent hybridization conditions may include temperatures as low as 40-42° C. (when denaturants such as formamide are included) or up to 60-65° C. in ionic strengths as low as 0.1×SSC. These ranges, however, are only illustrative and, depending upon the nature of the target sequence and possible future technological developments, may be more stringent than necessary.
[0021] In yet another embodiment, the invention provides a method for the preparation of a diagnostic assay to detect the presence of CMT2B in a human comprising detecting at least one mutation in the nucleotide sequence of SEQ ID NO:169 in a tissue sample of the human, wherein the mutation results in a dominant mutation of RAB7 and wherein the presence of the mutation is indicative of a predisposition or the presence of CMT2B.
[0022] In yet another embodiment, the invention provides a method for the preparation of a diagnostic assay to detect the presence of a peripheral neuropathy, more particularly CMT2B, in a human comprising detecting at least one mutation in the nucleotide sequence of SEQ ID NO:169 in a tissue sample of the human, wherein the mutation is derived from Table 1A and wherein the presence of the mutation is indicative of a predisposition or the presence of a peripheral neuropathy, more particularly CMT2B.
[0023] In yet another embodiment the invention provides a method for the preparation of a diagnostic assay to detect the presence of a peripheral neuropathy, more particularly HMSN, in a human comprising detecting at least one mutation in the nucleotide sequence of SEQ ID NO:171 in a tissue sample of the human, wherein the mutation is derived from Table 1B and wherein the presence of the mutation is indicative of a predisposition or the presence of a peripheral neuropathy, more particularly HMSN.
[0024] When a diagnostic assay is to be based upon RAB7 and/or ARHGEF10 proteins, a variety of approaches are possible. For example, diagnosis can be achieved by monitoring differences in the electrophoretic mobility of normal and mutant RAB7 and/or ARHGEF10 protein. Such an approach will be particularly useful in identifying mutants in which charge substitutions are present or in which insertions, deletions or substitutions have resulted in a significant change in the molecular mass of the resultant protein. Alternatively, diagnosis may be based upon differences in the proteolytic cleavage patterns of normal and mutant RAB7 and/or ARHGEF10 protein, differences in molar ratios of the various amino acid residues, or by functional assays demonstrating altered function of the gene products. In some preferred embodiments, protein-based diagnostics will employ differences in the ability of antibodies to bind to normal and mutant RAB7 and/or ARHGEF10 proteins. Such diagnostic tests may employ antibodies which bind to the normal proteins but not to mutant proteins, or vice versa. In particular, an assay in which a plurality of monoclonal antibodies, each capable of binding to a mutant epitope, may be employed. The levels of anti-mutant examples binding in a sample obtained from a test subject (visualized by, for example, radiolabeling, ELISA or chemiluminescence) may be compared to the levels of binding to a control sample. Such antibody diagnostics may be used for in situ immunohistochemistry using biopsy samples of (CNS) tissues obtained ante mortem or post-mortem or may be used with fluid samples, such as cerebrospinal fluid, or with peripheral tissues, such as white blood cells.
[0025] In another embodiment, the invention provides a transgenic non-human animal comprising a vector comprising a dominant mutant of RAB7.
[0026] In yet another embodiment, the invention provides a transgenic non-human animal comprising a vector comprising a mutation of RAB7 listed in Table 1A.
[0027] In a further embodiment, the invention provides a transgenic non-human animal comprising a vector comprising a dominant mutant of ARHGEF10.
[0028] In a yet further embodiment, the invention provides a transgenic non-human animal comprising a vector comprising a mutation of ARHGEF10 listed in Table 1B.
DESCRIPTION OF THE FIGURES
[0029] FIG. 1 illustrates the DNA and protein sequence analysis of RAB7. Panel A is an electropherogram showing the C385T (also commonly referred to as c.385C>T and 385C→T) sequence variation in part of exon 3 resulting in the Leu129Phe missense mutation in families CMT-140 and CMT-126, and the isolated patient CMT-186.26 (see SEQ ID NO:173). Panel B is an electropherogram of the G484A (also commonly referred to as c.484G>A and 484G→A) sequence variation in part of exon 4 resulting in the Val162Met missense mutation in families CMT-90 and CMT-195, and the isolated patients CMT-186.28 and PN626.1 (see SEQ ID NO:175). The corresponding genomic sequence of a control person is shown below. Panel C shows clustalW multiple protein alignment (http:H/npsa-pbil.ibcp.fr/cgi-bin/npsa_automat.pl?page=npsa_clustalw.html) of the Rab7 orthologs of the region surrounding the Leu129Phe and Val162Met mutations (SEQ ID NOS:177-184, in order from top to bottom). Rab7 orthologs: Human ( H. sapiens ), mouse ( M. musculus ), rat ( R. norvegicus ), fly ( D. melanogaster ), slime mold ( D. discoideum ), nematode ( C. elegans ), mouse-ear cress ( A. thaliana ), and baker's yeast ( S. cerevisiae ). The highly conserved motif involved in guanine nucleotide binding is boxed. Both amino acid mutations are shaded and indicated by an arrow.
[0030] FIG. 2 depicts a haplotype analysis of chromosome 8p23 STR markers in family CMT-54 and PN-648. Legend to the symbols: squares=male, circle=female, open=unaffected, filled=affected, slashed=deceased, arrow=recombination event, box=disease-associated haplotype. The best genetic and physical order of STR markers is according to NCBI. Genotypes are represented by allele numbers, and “0-0”=failed genotype. The ARHGEF10 gene is located between markers D8S156 and D8S264. The clinical, neurophysiological and neuropathological findings in family CMT-54 have been reported in detail elsewhere (De Jonghe et al. 1999). In family PN-648, the single patient III-3 is a female of 54 years old. Her mother deceased at 65 years because of breast cancer and her father deceased at 89 years old. No neurological diseases were found in her relatives. At age 4 to 5 years old, her clinical history started with walking disturbances. Two years later, slight distal hypotrophy of legs and arms was noticed. At 8 years, she walked with difficulty and limb distal atrophy was more evident. At 11 years, she was not able to walk unassisted and at 14 and 16 years, she underwent surgical operation on the knee and feet, respectively, due to severe ankylosis. Her clinical picture remained stable from 16 to 30 years and she was able to walk if assisted. At 30 years of age, she developed a dorso-lumbar kypho-scoliosis and 7 years later she became wheel-chair bound. The MRI of brain and spinal cord were normal. At 49 years old, she showed severe distal hypotrophy of arms and legs and in the hands and feet, only bone structures were appreciable. The upper limbs showed important weakness in the proximal muscles; developed severe weakness of forearm and hand (Medical Research Council, MRC score=0). The lower limbs showed important proximal weakness, severe distal weakness, dropping feet, absent deep tendon reflexes and sensory disturbances. Because of the almost complete absence of muscular tissue, it was impossible to perform a neurophysiological study. Electromyography was performed when she was 30 years old; the motor NCVs were not evoked in the right sciatic-popliteus and median nerves, and the sensory NCVs were reduced on the right median nerve. At 49 years old, the sensory and motor NCV were not evoked in the ulnar nerve. Finally, the sural nerve biopsy of patient PN-648 III-3′ showed severe reduction in the density of myelinated fibers (about 85-90% of fibers were lost). The large size fibers were absent. There were no classical onion bulb formations (only some early and simple onion bulbs were observed) and the endoneural connective tissue was increased.
[0031] FIG. 3 is a genetic map of the 8p23 chromosomal region. Legend: Map showing the contigs covering the 8p23 region and the distribution of the ten polymorphic markers used for haplotyping family CMT-54. Approximate genetic distances are according to GenBank. The location of the candidate genes, KIAA0711 (hypothetical protein KIAA0711), MYOM2 (myomesin (M-protein) 2), CLN8 (ceroid-lipofuscinosis, neuronal 8), DLGAP2 (discs, large ( Drosophila ) homolog-associated protein 2) and ARHGEF10 (Rho guanine nucleotide exchange factor 10), screened for mutations are indicated. Arrows define the recombination events in candidate region for CMT-54. D8Skris4 is also designated as STR1, D8Skris9 is also designated as STR2, D8SkrisCA2 is also designated as STR3, D8Skris6 is also designated as STR4).
[0032] FIG. 4 depicts mutation analysis of ARHGEF10. Panel A includes electropherograms showing the C326T (also commonly referred to as c.326C>T and 326C→T), sequence variation in exon 3 resulting in the Thr109lle missense mutation in family CMT-54 and the A2111G (also commonly referred to as c.211A>G and 211A→G) sequence variation in exon 17 resulting in the Asn704Ser missense mutation in patient PN-648.1 (see SEQ ID NOS:185 and 187, respectively). The corresponding genomic sequence of a control person is shown in the electropherogram below. Panel B includes clustalW multiple protein alignment of the human ( Homo sapiens ), mouse ( Mus musculus ), fugu ( Fugu rubripes ), rat ( Rattus norvegicus ) and macaque ( Macaca fascicularis ) GEF10 orthologues SEQ ID NOS:189-197, in order, from top to bottom). Both amino acid mutations Thr109lle and Asn704Ser are shaded.
DETAILED DESCRIPTION OF THE INVENTION
[0033] Since the isolated RAB7 and/or ARHGEF10 mutations are dominant (dominant negative), an alternative method for constructing a cell line is to engineer a genetically mutated gene, or a portion thereof, into an established (either stably or transiently) cell line of choice. In another embodiment, the present invention provides a transgenic non-human animal that carries in its somatic and germ cells at least one integrated copy of a human DNA sequence that encodes a mutant RAB7 and/or ARHGEF10 protein or fragment thereof. It is expected that the transgenic non-human animal, for example a transgenic mouse, will have a particular value because, likewise in the human CMT2B patients with the same pathogenic mutations in RAB7, a transgenic animal with an axonal phenotype is expected. In a preferred example, it may be possible to excise the mutated RAB7 and/or ARHGEF10 gene for use in the creation of transgenic animals containing the mutated gene. In another example, an entire human RAB7 mutant allele and/or an entire human ARHGEF10 mutant allele may be cloned and isolated, either in parts or as a whole, in a cloning vector (e.g., cosmid or yeast or human artificial chromosome). The human variant RAB7 mutant and/or ARHGEF10 mutant, either in parts or in whole, may be transferred to a host non-human animal, such as a mouse or a rat. As a result of the transfer, the resultant transgenic non-human animal will preferably express one or more mutant RAB7 and/or ARHGEF10 polypeptides. Most preferably, a transgenic non-human animal of the invention will express one or more mutant RAB7 and/or ARHGEF10 polypeptides in a motor neuron-specific manner (e.g., dorsal root ganglia). Alternatively, one may design minigenes encoding mutant RAB7 and/or ARHGEF10 polypeptides. Such mini-genes may contain a cDNA sequence encoding a mutant RAB7 and/or ARHGEF10 polypeptide, preferably full-length, a combination of RAB7 and/or ARHGEF10 gene exons, or a combination thereof, linked to a downstream polyadenylation signal sequence and an upstream promoter (and preferably enhancer). Such a mini-gene construct will, when introduced into an appropriate transgenic host (e.g., mouse or rat), express an encoded mutant RAB7 and/or ARHGEF10 polypeptide.
[0034] Another approach to create transgenic animals is to target a mutation to the desired gene by homologous recombination in an embryonic stem (ES) cell line in vitro, followed by microinjection of the modified ES cell line into a host blastocyst and subsequent incubation in a foster mother (see Frohman and Martin (1989) Cell 56:145). Alternatively, the technique of microinjection of the mutated gene, or a portion thereof, into a one-cell embryo followed by incubation in a foster mother can be used. Various uses of transgenic animals are known in the art. Alternatively, site-directed mutagenesis and/or gene conversion can be used to mutate a murine (or other non-human) RAB7 and/or ARHGEF10 gene allele, either endogenous or transfected. The procedure for generating transgenic rats is similar to that of mice (Hammer et al., Cell 63; 1099-112 (1990)). Thirty day-old female rats are given a subcutaneous injection of 20 IU of PMSG (0.1 cc) and 48 hours later, each female placed with a proven male. At the same time, 40-80 day old females are placed in cages with vasectomized males. These will provide the foster mothers for embryo transfer. The next morning, females are checked for vaginal plugs. Females who have mated with vasectomized males are held aside until the time of transfer. Donor females that have mated are sacrificed (CO 2 asphyxiation) and their oviducts removed, placed in DPBS (Dulbecco's phosphate buffered saline) with 0.5% BSA and the embryos collected. Cumulus cells surrounding the embryos are removed with hyaluronidase (1 mg/ml). The embryos are then washed and placed in EBSS (Earle's balanced salt solution) containing 0.5% BSA in a 37.5° C. incubator until the time of microinjection. Once the embryos are injected, the live embryos are moved to DPBS for transfer into foster mothers. The foster mothers are anesthetized with ketamine (40 mg/kg, ip) and xylazine (5 mg/kg, ip). A dorsal midline incision is made through the skin and the ovary and oviduct are exposed by an incision through the muscle layer directly over the ovary. The ovarian bursa is torn, the embryos are picked up into the transfer pipet, and the tip of the transfer pipet is inserted into the infundibulum. Approximately 10-12 embryos are transferred into each rat oviduct through the infundibulum. The incision is then closed with sutures, and the foster mothers are housed singly.
EXAMPLES
[0000] 1. RAB7
[0035] A molecular genetic study of three families with an ulcero-mutilating phenotype that were previously linked to the CMT2B locus 7-9 was performed. To determine whether the American (CMT-195), 7 Scottish (CMT-90) 8 and Austrian (CMT-140) 9 families share a common disease-associated haplotype, 15 STR markers in the CMT2B region were analyzed. These markers included six new polymorphic STR markers (D3SCMT126A, D3SCMT126B, D3SCMT126C, D3SCMT126D, D3SCMT126F and D3SCMT126G) that were isolated by using sequence information from the public databases. For each marker, alleles associated with the ulcero-mutilating phenotype were identified and a disease haplotype was constructed in each family. No common disease haplotype was found in families CMT-195, CMT-90 and CMT-140, suggesting the absence of a genetic relationship between the CMT2B families. However, a common disease haplotype spanning nine STR markers, from D3S3519 to D3SCMT126C, was shared between the Austrian family CMT-140 and a small branch of the Austrian multigenerational pedigree CMT-126 (patients III-5, IV-2, IV-3 and V-1), originally excluded for the CMT2B locus. 3 Although the five remaining patients (III-1, III-2, III-3, III-6 and IV-6) with an ulcero-mutilating phenotype in CMT-126 do not have the same disease haplotype, it is highly unlikely that CMT-140 and part of the CMT-126 family share the same alleles over a nine-marker interval by chance.
[0036] In family CMT-140 and CMT-126, recombination in affected individuals V-10, V-12, V-13 and VI-5 between markers D3S1589 and D3S3584, mapping the CMT2B locus telomeric to D3S1589 was observed. The informative recombination in CMT-126 (III-5, IV-2, IV-3 and V-1) maps the CMT2B locus centromeric to marker D3SCMT126D. These data refine the CMT2B region to 2.5 cM, between D351589 and D3SCMT126D. In the CMT2B locus, three known positional candidate genes for mutation analysis in the CMT2B families were selected: ZNF9 (zinc finger protein 9), ABTB1 (ankyrin repeat and BTB domain containing 1), and RAB7 (small GTPase late endosomal protein RAB7). For each gene, all known exons and intron-exon boundaries in CMT2B patients were sequenced and no disease-causing mutations were found in ZNF9 and ABTB1. However, in exon 3 of RAB7, a C385T mutation (Leu129Phe) in family CMT-140 and in the small branch of family CMT-126 was found ( FIG. 1 , Panel A). A second G484A mutation (Val162Met) in exon 4 was found in families CMT-195 and CMT-90 ( FIG. 1 , Panel B). The missense mutations segregate with the CMT2B phenotype in all pedigrees and were not found in 200 control chromosomes. The cumulative LOD score, at 0% recombination, for segregation of the disease-causing mutation in CMT-140 and the small branch of CMT-126 is 8.23, and the LOD score in CMT-90 and CMT-195 is 1.49 and 4.13, respectively. Interestingly, the remaining patients of family CMT-126 (III-1, III-2, III-3, III-6 and IV-6) do not have the Leu129Phe mutation in RAB7. The fact that individuals III-5, IV-2, IV-3 and V-1 of CMT-126 have the same disease-associated haplotype and the same C385T (Leu129Phe) mutation as the patients in CMT-140 ( FIG. 1 , Panel A), indicates that there is a familial relationship between CMT-140 and a part of CMT-126, who both originate from the South of Austria (Carinthia). The ulcero-mutilating phenotype of the remaining patients in CMT-126 is probably caused by a mutation in another gene (as SPTLC1 is excluded) and further supports the presence of a third locus for ulcero-mutilating neuropathies. The alignment of RAB7 orthologs shows that both missense mutations target highly conserved amino acid residues ( FIG. 1 , Panel C, SEQ ID NOS:177-184). The Val162Met mutation affects a valine that is conserved among all species. The Leu129Phe mutation is located next to a conserved GTP-binding domain (-NKID-). Leul29 is not conserved in Arabidopsis and yeast. Vitelli et al. reports an expression of two transcripts of 2.5 and 1.8 kb for the human RAB7 gene in different cell types. The expression information of human and mouse RAB7 in the Unigene database suggests ubiquitous expression (Unigene Clusters: Hs.356386 and Mm.4268). Expression was found in all tested tissues. However, in human, the highest level of expression was found in skeletal muscle, while in mouse, the liver, heart and kidney had a high level of expression. Analysis of cDNA from mouse sensory (DRGs) and motor neurons (ventral horn) showed expression of RAB7 in both cell types. In conclusion, two missense mutations in the RAB7 late endosomal protein were reported as the cause for the ulcero-mutilating inherited peripheral neuropathy CMT2B.
[0000] 2. ARHGEF10
[0037] The phenotype of slowed motor and sensory nerve conduction velocities (NCVs) in a four-generation family (CMT-54 family; De Jonghe et al, (1999) Arch. Neurol. 56:1283-1288), was accidentally discovered upon clinical and electrophysiological examination of the proband III-16 for vascular problems of the leg. Subsequent examination identified slowed NCVs in 12 of 39 healthy relatives (5 males, 7 females) indicating an autosomal dominant inheritance of the phenotype. NCVs were uniformly slowed in all nerves examined: 34 to 42 m/s for motor median nerve (normal≧49 m/s), 27 to 36 m/s for motor peroneal nerve (normal≧41 m/s), 32 to 46 m/s for sensory median nerve (normal≧46 m/s), 33 to 45 m/s for sensory ulnar nerve (normal≧46 m/s), and 28 to 35 m/s for sensory sural nerve (normal≧44 m/s). Compound muscle action potentials were normal and sensory nerve action potentials were sometimes slightly reduced. None of the affected family members showed any clinical signs of peripheral or central nervous system dysfunction. The eldest individuals II-4 and II-7, respectively 87 and 78 years old at neurological examination, had NCVs that were not significantly different from those measured in younger affected. Histological studies of a peripheral nerve biopsy of the proband III-16 at 54 years showed numerous relatively thin myelin sheaths (mean g-ratio: 0.75 for myelinated fibers ranging from 2 μm to 7 μm), slight onion bulb formation and few axonal regeneration clusters. Family CMT-54 was excluded of all known loci for inherited peripheral neuropathies, indicating that this family represents a novel clinical and genetic entity of HMSN.
[0038] In order to map the disease locus in family CMT-54, a genome-wide scan using 382 short tandem repeat (STR) markers (ABI Prism® Linkage Mapping Set MD-10 (PE Biosystems)), which have an average inter-marker distance of 10 cM, was performed. Significant linkage with STR marker D8S264 on the short arm of chromosome 8 (LOD score=3.01 at 0% recombination, Table 3) was found. To fine-map the disease locus on 8p, five known STR markers (D8S504, D8S44 (AF009213), D8S156 (AF009208), D8S1806 and D8S1824) were selected and four new STR markers (STR1, STR2, STR3 and STR4) flanking D8S264 were identified by using sequence information from public databases (Table 4, FIG. 3 ). Two-point linkage analysis demonstrated positive LOD scores for all makers tested. A maximum LOD score of 9.33 was obtained with the most informative marker AF009213 (Table 3). For each marker, alleles associated with the HMSN phenotype were identified and a disease haplotype was constructed in family CMT-54 ( FIG. 2 , Panel A). In patients II-3, III-1, III-3 and III-9, the disease haplotype covers the ten STR markers. Patient II-6 has a recombination with markers STR2, STR3, STR4, D8S1806 and D8S1824, which is inherited by his four affected children (III-14, III-19, III-21 and III-25). The healthy relative III-24 carries a part of the disease haplotype at marker STR1 and D8S504. These recombination events assign the disease locus in family CMT-54 between the telomeric marker D8S504 and centromeric marker STR2. Physical mapping data demonstrated that the region is covered by sequenced clone contigs NT — 008060, NT — 037694 and NT — 023744, representing ±1.5 Mb (NCBI, LocusLink) ( FIG. 3 ). In the novel HMSN locus on chromosome 8p23, five positional candidate genes for mutation analysis were selected: KIAA0711 (hypothetical protein KIAA0711), MYOM2 (myomesin (M-protein] 2), CLN8 (ceroid-lipofuscinosis, neuronal 8), DLGAP2 (discs, large [ Drosophila ] homolog-associated protein 2) and ARHGEF10 (Rho guanine nucleotide exchange factor 10). For each gene, all known exons and intron-exon boundaries in patients from family CMT-54 and healthy controls were selected. No disease-associated mutations were found in MYOM, CLN8, DLGAP3 and KIAA0711. Subsequently, the 8467 bp mRNA sequence of ARHGEF10 (NM — 014629) with the sequence of contig NT — 023744 were annotated and 22 coding exons were retrieved, spanning a genomic size of 136160 bp (Table 5). In exon 3 of ARHGEF10, a heterozygous C→T transition mutation at nucleotide coding position 326 (C326T, Thr109lle) in patients III-9 and III-19 was found ( FIG. 4 , Panel A). This Thr109lle missense mutation co-segregated with the disease phenotype in family CMT-54. Subsequently, 95 patients with an HMSN phenotype, previously excluded for mutations in the common CMT genes PMP22, MPZ and connexin 32 (GJB1), were screened. In patient III-3 of an Italian family (PN-648), an A→G transition at coding position 2111 (A2111G, Asn704Ser) in exon 17 of ARHGEF10 was found ( FIG. 4 , Panel A). Since the parents of patient III-3 were not available for mutation analysis, no determination could be made as to whether the Asn704Ser mutation occurred de novo or whether it was inherited as an autosomal dominant trait. The patient's healthy brother and other relatives did not carry the Asn704Ser mutation or the disease-associated haplotype with STR markers from the novel HMSN locus on chromosome 8p23 ( FIG. 2 , Panel B, SEQ ID NOS:189-197). Both missense mutations, Thr109lle in CMT-54 and Asn704Ser in PN-648, were not found in 600 normal control chromosomes. The ARHGEF10 protein contains 1121 amino acids and contains a conserved dbl homology (DH) domain from codon 177 to 359 (ScanProsite, http://us.expasy.org/cgi-bin/scanprosite).
[0039] The CLUSTALW protein alignment of human ARHGEF10, macaque, puffer fish, rat and mouse Gef10 orthologues showed that the Thr109lle and Asn704Ser missense mutations target highly conserved amino acid residues ( FIG. 4 , Panel B, SEQ ID NOS:189-197).
[0040] Expression of ARHGEF10 using its mouse orthologue Gef10 was examined. Alignment of the Gef10 transcript of 4481 bp (NM — 172751) with the genomic sequence NT — 039455 identified 24 exons, exons 1 and 2 being absent from ARHGEF10. Multiple tissue Northern blot analysis of Gef10 indicated ubiquitous expression. Overlapping primer sets covering the mouse cDNA sequence were used in PCR analysis on cDNA of E13 mouse brain, dorsal root ganglia (DRG) and ventral horn (VH) and demonstrated Gef10 expression in all three neuronal tissues. Extra PCR fragments were observed that indicated the presence of alternative transcripts. Sequencing of these fragments identified three splice variants of Gef10: one in all three tissues missing exon 4, one specific for DRG missing exon 21, and one specific for VH with an insertion of an additional exon of 165 bp between exons 22 and 23. Exon 5 corresponding with exon 3 in ARHGEF10 and containing the Thr109lle mutation, is present in all three variant transcripts. Whole mount in situ hybridization experiments in mouse embryos at E8.5 showed Gef10 expression in the neuroepithelium of the meninges, including the optic sulcus. At E9.5, high levels of Gef10 expression were detected in the roof plate of the rhombencephalon. In E12.5 embryos, Gef10 is ubiquitously expressed with a pronounced expression in the neuroepithelium of brain vesicles, the neural tube, the ganglia, DRG and the neural layer of the retina.
[0041] ARHGEF10 encodes a guanine nucleotide exchange factor for the Rho family of GTPase proteins (RhoGEFs), and contains a DbI homology (OH) domain (codons 177 to 359), a common feature of all RhoGEFs. RhoGEFs activate RhoGTPases by catalyzing the exchange of bound GDP for GTP, inducing a conformational change in the GTP-bound GTPase that allows its interaction with downstream effector proteins. Within the RhoGEF family, DH domains are invariably followed by a pleckstrin homology (PH) domain supposed to be involved in subcellular localization of RhoGEFs. However, in ARHGEF10, a PH domain consensus motif using several bioinformatic tools (BlastP, ScanProsite or InterPro) was not detected. So far, only one other mammalian RhoGEF family member, p164-RhoGEF, lacking the PH domain has been reported. ARHGEF10 appears to lack an equivalent protein in C. elegans, D. melanogaster, D. discoideum and S. cerevisiae, suggesting that the ARHGEF10 signaling pathway is unique to vertebrates. This confirms the overall picture of plasticity when comparing the RhoGTPases and their interacting proteins between species, with certain species gaining or losing RhoGTPase and RhoGEF family members to give rise to unique sets of signaling proteins. RhoGTPases play a pivotal role in regulating the actin cytoskeleton but their ability to influence cell polarity, microtubule dynamics, membrane transport pathways and transcription factor activity is probably just as significant. Recent evidence has implicated RhoGTPases in neuronal morphogenesis, including cell migration, axonal growth and guidance, dendrite elaboration and plasticity, and synapse formation. Several GEFs play a central role in defining the temporal and spatial activation of the corresponding GTPase within neuronal cells.
[0042] The identification of ARHGEF10 as a gene implicated in peripheral nerve conduction raises questions about its role during the development of the peripheral nervous system in vertebrates. All affected members in the family had slowed NCVs with normal amplitudes at all ages, indicating that the phenotype is non-progressive. Together with the numerous thin myelinated axons in the absence of gross signs of demyelination or axonal de- and regeneration in the peripheral nerve biopsy of the proband, without wishing to be bound by theory, one possible theory is that these observations are indicative of a congenital non-progressive phenotype, suggesting that ARHGEF10 is most likely involved in normal development of peripheral nerves.
Materials and Methods
[0000] 1. RAB7
[0043] 1.1. Family Material
[0044] The study described herein comprised three families previously linked to the CMT2B locus on 3q13-q22, the originally described American CMT2B family, 7, 20 a Scottish family CMT-90, 8 and an Austrian family CMT-140. 9 In addition, another Austrian family, CMT-126, previously excluded for the CMT2B and HSN I loci, 3 was studied. In summary, the clinical picture of CMT2B is mild to severe, with sensory loss and all modalities equally affected. Spontaneous pain is absent. Motor deficits are often the first and most prominent sign of the disease. The distal leg muscles are more affected than the hand muscles. Nerve conduction velocity (NCV) studies indicate an axonal neuropathy that allows clinical diagnosis in asymptomatic individuals (reviewed in reference 2). Genomic DNA from total blood samples from family members and control persons using a standard extraction protocol was isolated. Informed consent was obtained from all family members and this study was approved by the Institutional Review Board at the Universities of Antwerp, Edinburgh, Graz, and St Louis.
[0045] 1.2. Molecular Genetics
[0046] From sequences of human High Throughput Genomic Sequences (HTGS) clones localized in the CMT2B region (NT — 031776, NT — 005543, NT — 005588, NT 028133, NT — 022513, NT — 005523, NT — 006025, NT — 022404, NT 005823), known STR sequences were selected and six new STR markers by BLASTN searches were identified (NCBI site at http://www.ncbi.nlm.nih.gov/BLAST/): D3SCMT126A, D3SCMT126B, D3SCMT126C, D3SCMT126D, D3SCMT126F and D3SCMT126G. For genotyping STRs, primer pairs were designed. PCR amplification was performed with dye-labeled primers on a DYAD thermocycler (MJ Research). Fragment analysis was performed on an ABI3700 DNA sequencer and analyzed with the ABI GENESCAN 3.1 and GENOTYPER 2.1 software (Perkin-Elmer, Applied Biosystems Inc.). Genetic linkage was computed with the LINKAGE program (http://linkage.rockefeller.edu/) considering the disease-causing mutation as rare allele (1%), equal male and female recombination fractions and a disease frequency of 1/10,000.
[0047] 1.3. Mutation Analysis
[0048] The NCBI Entrez Genome Map Viewer (http://www.ncbi.nlm.nih.gov/cgi-bin/Entrez/hum_srch?chr=hum_chr.inf&query), Ensembl Human Genome Server (http://www.ensembl.org/) and Genbank database (http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=Nucleotide) were used to find known genes, ESTs and putative novel genes in the CMT2B region. The exon-intron boundaries of the candidate sequences were determined by BLAST searches against the HTGS. All exons of the ZNF9, ABTB1 and RAB7 genes were PCR-amplified using intronic primers (Table 2, SEQ ID NOS:3-70). PCR products were sequenced using the DYEnamic ET Terminator Cycle Sequencing Kit (Amersham Pharmacia Biotech). The sequence reactions were loaded on the ABI3700 sequencer (Perkin-Elmer, Applied Biosystems Inc.). The data were collected and analyzed using the ABI DNA sequencing analysis software, version 3.6.
[0049] 1.4. Expression Analysis
[0050] Three plasmid clones, IMAGp956B0837, IMAGp956M0263 and IMAGp956M2246, containing partial human RAB7 cDNA sequences were obtained from RZPD (The Resource Center of the German Human Genome Project at http://www.rzpd.de/). T3- and T7-primers were used to make a RAB7 cDNA probe of 800 bp. This probe was used to hybridize the Human 12-lane Multiple Tissue Northern blot (Clontech).
[0051] Total RNA was extracted from mouse brain (NMRI) using the Totally RNA Kit (Ambion). RT-PCR was carried out using the SMART RACE cDNA Amplification kit (Clontech). The full length mouse RAB7 cDNA was cloned into the pCRII-TOPO vector (Invitrogen) and used as a probe to hybridize the Mouse Multiple Tissue Northern blot (Clontech). Both Northern blots were also hybridized with a β-actin cDNA probe (Clontech) as a control for RNA loading.
[0052] Motor and sensory neurons were isolated from 13 day-old mice embryos. Total RNA was extracted using the Totally RNA Kit (Ambion) and RT-PCR was carried out using the SMART RACE cDNA Amplification kit (Clontech). Mouse RAB7 cDNA primers (MRAB7-2F=5′-CTGACCAAGGAGGTGATGGT-3′ (SEQ ID NO:1) and MRAB7-2R=5′-GAACAGTTCTCACTCTCC-3′ (SEQ ID NO:2)) were used to amplify a RAB7 cDNA fragment of 854 bp.
[0053] 1.5. Genbank Accession Numbers
[0054] Protein sequences: RAB7_human, P51149 (SEQ ID NO:170); RAB7_mouse, P51150 (SEQ ID NO:178); RAB7 rat, P09527 (SEQ ID NO:179); Rab-protein 7 Drosophila melanogaster, NP — 524472 (SEQ ID NO:180); RAB7 — Dictyostelium discoideum, P36411 (SEQ ID NO:181); Ras-related protein — Caenorhabditis elegans, NP 496549 (SEQ ID NO:182); RAB7 — Arabidopsis thaliana, O 04157 (SEQ ID NO:183); YPT7_YEAST, P32939 (SEQ ID NO:184).
[0000] 2. ARHGEF10
[0055] 2.1 Electronic Database Information
[0056] Accession numbers and URLs for data presented herein are as follows:
[0057] ClustalW, http://npsa-pbil.ibcp.fr/ (for multiple protein alignment).
[0058] GenBank, http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=Nucleotide for mRNA sequences: Myomesin (M-protein) 2 (MYOM2), NM — 003970; KIAA0711, NM — 014867; Rho guanine nucleotide exchange factor (GEF) 10 (ARHGEF10), NM — 014629; ceroid-lipofuscinosis neuronal 8 (CLN8), NM — 018941; discs, large ( Drosophila ) homolog-associated protein 2 (DLGAP2), NM — 004745. For Protein sequences: Homo sapiens Rho guanine nucleotide exchange factor (GEF) 10, NP — 055444; Mus musculus sequence similar to GEF10, NP-766339; Macaca fascicularis brain cDNA similar to GEF10, BAB12119; Rattus norvegicus protein similar to GEF10, XP — 225032; Fugu rubripes.
[0059] NCBI Map Viewer, (http://www.ncbi.nlm.nih.gov/cgi-bin/Entrez/hum_srch?chr=hum_chr.inf&guery (for finding known genes, ESTs, and putative novel genes in the 8p23 region.
[0060] Online Mendelian Inheritance in Man (OMIM), http://www.ncbi.nlm.nih.gov/Omim/ (for CMT (MIM # 118220)).
TABLES
[0061]
TABLE 1A
Mutations in RAB7 causing CMT2B
Mutation
Exon
Family/Patient
(cDNA, Protein)
3
CMT-140, CMT-126 (part), CMT-1 86.26
C385T, Leu129Phe
4
CMT-90, CMT-195, CMT-186.28, PN-626.1
G484A, Val162Met
[0062]
TABLE 1B
Mutations in ARHGEF10 causing HMSN
Exon
Family/Patient
Mutation (cDNA, Protein)
3
CMT-54
C326T, Thr109lle
17
PN-648
A2111G, Asn704Ser
[0063]
TABLE 2
The exons of the ZNF9, ABTB1 and RAB7 genes were PCR-amplified using the following intronic primers
(SEQ ID NOS:3-70, in sequential order, left to right and top to bottom):
PCR
Gene
Exon
Forward primer
5-intron/exon
3′-intron/exon
Reverse primer
length
ZNF9
exon
5′-GATTACTGGCGTGAGCCACC-3′
cagccATGAG
TAGAGgtatt
5′-GGCTAGTCAGACCAGTCTTG-3′
361 bp
1
exon
5′-CAAGACTGGTCTGACTAGCC-3′
aacagGTTTC
GGATGgtaag
5′-CACAGTTGCATGTGCTCACC-3′
291 bp
2
exon
5′-GGTGAGCACATGCAACTGTG-3′
tgaagCCTGC
TATAGgtaag
5′-GCCACAGGATATCAGGGCAG-3′
511 bp
3
exon
5′-GCATGGTGACTGTTGCTTTG-3′
tttagGTGTG
CCTAAttatt
5′-GGGAGTTGCCTCTATCTGCC-3′
290 bp
4
ABTB1
exon
5′-GTCTGATGAGCCTGGCCCAG-3′
agaccATGGG
TGCAGgtagc
5′-GGCAAGGAAATGGTCACCTG-3′
331 bp
1
exon
5′-CATGACCTGATGACCCCTGC-3′
cttagATTAT
5′-GAAAAGTCACGGACCTGAGG-3′
394 bp
2A
exon
5′-CTGGCATATGCCTCCCAGAG-3′
5′-CGCTTGCTTCCTGAGGAGCC-3′
395 bp
2B
exon
5′-CTCCACCAGCCAAGAGGCAG-3′
CGCAGgtaaa
5′-GCCAGGCTCTGTGAAAGAAG-3′
410 bp
2C
exon
5′-CACTGGCCTCCACCTTCCAG-3′
cacagGTGAT
ACTGTgtgag
5′-CACTGCCTGCAGCCTTTCCC-3′
234 bp
3
exon
5′-GAGGGTTGAGGGTGAGTACG-3′
tgtagGAGGT
GCAGGgtgag
5′-CAAAGCCCTTATGCGTGCAC-3′
351 bp
4
exon
5′-GAGACAGAGGCTCAGGCCAG-3′
cccagGGGTG
AGGAGgtaag
5′-CGATGTGGGCAGACTCCTGG-3′
254 bp
5
exon
5′-CCAATGCAACCACCCCAGAG-3′
cctagATTGG
ACGTGgtgag
5′-GCAGATGAGGACACCTATCG-3′
326 bp
6
exon
5′-GATCGATGACGTCAGGGAGG-3′
ctcagTCGCA
TGTGAgcgca
5′-CCGAGGCCGATCCAGTTATC-3′
510 bp
7
RAP7
exon
5′-GGCTGCTCAGACATTTGTGC-3′
gaaggATGAC
TCTGGgtaag
5′-GAAGTGGCAGCACGGACAGT-3′
233 bp
1
exon
5′-GTCCTTCAGGTCAGGCAGATT-3′
ttcagAGTCG
TGCAGgtaag
5′-CTGAGTATCAGCCAATTATC-3′
365 bp
2
exon
5′-GCACCCCTTGCATACATGCT-3′
cacagATATG
GACAAgtaag
5′-GTGAGCTTAGCAGAGAACC-3′
377 bp
3
exon
5′-GAGGATGGAGTCAGTGCTGG-3′
ttcagGTGGC
AGCAGgtggg
5′-GTCAGTGGTCAGGCATCACC-3′
244 bp
4
exon
5′-CACTCTGCCCAAGCAGAAGTG-3′
tccagGAAAC
CTGAgggggc
5′-GGAAGAGGAGAGGGGAATTG-3′
288 bp
5
[0064]
TABLE 3
Two-point linkage results with chromosome 8p23 markers.
LOD scores at recombination fraction Θ
0
0.001
0.01
0.05
0.1
0.2
0.3
0.4
STR1
6.32
6.31
6.22
5.81
5.26
4.05
2.68
1.19
D8S504
−∞
6.20
7.07
7.20
6.76
5.44
3.79
1.87
AF009208
6.98
6.97
6.87
6.41
5.82
4.58
3.19
1.60
D8S264
3.01
3.01
2.96
2.77
2.51
1.95
1.34
0.68
Thr109lle
9.93
9.91
9.78
9.17
8.37
6.64
4.68
2.46
AF009213
9.33
9.32
9.19
8.60
7.82
6.14
4.24
2.09
STR2
−∞
4.39
5.28
5.51
5.19
4.15
2.84
1.34
STR3
−∞
4.27
5.18
5.44
5.18
4.25
3.02
1.53
STR4
−∞
5.36
6.25
6.43
6.05
4.90
3.44
1.72
[0065] Legend: Two-point linkage analysis was performed using the MLINK program of the FASTLINK program package (Cottingham R. W. et al. (1993) Am. J. Hum. Genet. 53:252-263; Lathrop G. M. and Lalouel J.-M. (1984) Am. J. Hum. Genet. 36:460-465). Since NCV values were diagnostic in all individuals, the phenotype was coded as a 100% penetrant phenotype (De Jonghe et al. (1999) Arch. Neurol. 56:1283-1288). The gene frequency was set at 0.0001, allele frequencies were set at 1/N (N=number of alleles observed in the pedigree), and equal recombination rates between males and females were assumed. Sequences of the four new STR markers, STR1, STR2, STR3 and STR4, can be found in Table 4.
TABLE 4 Primer conditions for new STR markers on chromosome 8p23 (SEQ ID NOS:71-78): STR Primer pair: PCR product # NT Position in NT marker F = forward, R = reverse length alleles contig sequence STR1 F: 5′-CCTCATTCTGCAGCGAGATGG-3′ 285-307 bp 11 NT_008060 656446-656730 R: 5′-TGGACAGAGGCATGAGGAAGAC-3′ STR2 F: 5′-GTGCAGATTCACTGCTGCTAAC-3′ 188-216 bp 13 NT_023744 1244480-1244663 R: 5′-GAGCGAGAGAGACCACTGTAT-3′ STR3 F: 5′-GTTTGCTCATCTTGTACAGTGC-3′ 169-177 bp 4 NT_023744 1522783-1522955 R: 5′-CTGCAGTCCACTCTGGAAACA-3′ STR4 F: 5′-CCAAAAACCTTCAGCTGAGTC-3′ 139-159 bp 6 NT_023744 1589656-1589798 R: 5′-CAGGACGATATACGTGCACAC-3′
[0066]
TABLE 5
Oligonucleotide primer sequences used for mutation analysis and intron-exon boundaries of ARHGEF10
(SEQ ID NOS:79-168, in sequential order, left to right, top to bottom).
PCR
Ex-
Size
5′-intron/
3′-exon/
product
IVS
on
(bp)
Forward primer
exon
intron
Reverse primer
(bp)
(bp)
1
174
5′-CCCCAGCTCTAGATGATTTGG-3′
aattt/ATGCA
AGCAA/gtacg
5′-GGCAAAGGAGAAGACGTGTC-3′
424
3313
2
117
5′-CTGCCAGCATCCTCTCAATG-3′
tgtag/CTTTC
TGAAG/gtaga
5′-GTCCTTGCTGTCTCAACAGC-3′
294
2472
3
115
5′-CGTGACACATGCGCTCAGAAG-3′
cgcag/ATGCA
ACAGG/gtccg
5′-CTGCTCAGTGCTTGGGTCTG-3′
468
2851
4
107
5′-GCTGGGTGTCAAGTAAGCATG-3′
ttaag/ATCAC
AGCAG/gtgag
5′-GCTGTCTCAAACTCTGCATCC-3′
353
7863
5
78
5′-CAGCAAGCCTCAGCATAGAAG-3′
aacag/GTTGT
TGGAG/gtact
5′-GGATCTAAGTATTATGTCTG-3′
312
747
6
180
5′-GCTGCAGTGAGCCATGATCG-3′
cttag/CAATA
CTTCG/gtaat
5′-CTGATCTCCTGCAAGCTGAC-3′
390
1760
7
117
5′-GATCACAGTGACCGAAAGAG-3′
ttcag/TTTTC
TAAAG/gtaag
5′-CAGTATCAATAGTGCCCTAG-3′
349
1983
8
93
5′-GAGTGTTCAGTGTGGTGGGG-3′
cacag/CAGGA
TCCAG/gtaag
5′-GTTCCTCCACTTTGGAATGGC-3′
277
4756
9
171
5′-CTCCTTTCCATTGTCAGCTG-3′
tgtag/GACAT
ACAAG/gttga
5′-CTGTCGTTGTCCAGCAATAC-3′
342
2119
10
146
5′-CCTGAGACTCCATACCAGAC-3′
tccag/CTTCT
TGAGG/gtaag
5′-CTGTCACTGAGACTGAACTGG-3′
338
3578
11
176
5′-CAGCAACGGGAAGTTTCTCAC-3′
ttcag/GCCCT
ACCAA/gtaag
5′-GTAAGCTCCACCATCAGCAG-3′
372
13675
12
116
5′-GTTCTAGATTCACCCCTCAAC-3′
tgtag/ACAAA
ATCAG/gtaac
5′-CCAAGTTCTACCAGAAGTGAG-3′
331
388
13
128
5′-CAGTGTGATCTGACTCCCAAAG-3′
tgtag/AACTT
GACAA/gttag
5′-TGCTGATTCTATCAGACAGGC-3′
387
178
14
101
5′-GCTGATTCTATCAGACAGGC-3′
ggcag/ATCTG
CCTAG/gtaag
5′-GTGAGGTCAGGGTTGAGAAG-3′
278
1408
15
122
5′-CAGAATGCCAGAAACTTCCCC-3′
tgcag/AAGAG
TCAAG/gtgaa
5′-GTTCACCACAGTGACCGCTTC-3′
353
972
16
87
5′-GTAGTCTAGGAGCCTCTTAGC-3′
tttag/ATTGA
TGTGG/gtaag
5′-TTGCTCAGTAGAGAGTTGGCG-3′
252
1963
17
224
5′-GAAAATCGAAGCTTGTCGTGGC-3′
ttcag/ATCGG
GGAAG/gtagg
5′-GAGTCCTTGACTTTGACTCAGG-3′
425
635
18
158
5′-GCAAGTGTCCCTAGGAATGG-3′
taaag/CATTT
CCCAG/gtgag
5′-GACTGTGCATCCGGTTTAGC-3′
360
4359
19
143
5′-CATTACAGGTGATCCTTCGGG-3′
ttaag/ATGGA
TAGAG/gtaag
5′-GTGCCGAAGTCAAGGCTTC-3′
341
11574
20
175
5′-CTACTGTGTTGCAGCCAGTG-3′
cacag/GGTCA
GCCAG/gtaag
5′-CTTAGCGCTTCGCAGTGCAG-3′
386
7098
21
123
5′-GATTTGGTGGTGGCACGACA-3′
cccag/GGCAC
GACCG/gtgag
5′-CTCGTGGAGCATAGCAGTG-3′
295
3936
22
515
5′-GGAATGCGTTGGGGTTAAGC-3′
ttcag/GAAGA
5′-CTGAGCTTGTCTCACGGCTC-3′
380
A
22
5′-GAGTGGAGGAGCTGGTTCATC-3′
TATAA/gcagg
5′-GCTGTGTCTACACTGGTTGG-3′
462
B
[0067] Seq ID (SEQ ID NOS:169-172, in sequential order)
SEQ ID NO:169 atgacctcta ggaagaaagt gttgctgaag gttatcatcc tgggagattc tggagtcggg aagacatcac tcatgaacca gtatgtgaat aagaaattca gcaatcagta caaagccaca ataggagctg actttctgac caaggaggtg atggtggatg acaggctagt cacaatgcag atatgggaca cagcaggaca ggaacggttc cagtctctcg gtgtggcctt ctacagaggt gcagactgct gcgttctggt atttgatgtg actgccccca acacattcaa aaccctagat agctggagag atgagtttct catccaggcc agtccccgag atcctgaaaa cttcccattt gttgtgttgg gaaacaagat tgacctcgaa aacagacaag tggccacaaa gcgggcacag gcctggtgct acagcaaaaa caacattccc tactttgaga ccagtgccaa ggaggccatc aacgtggagc aggcgttcca gacgattgca cggaatgcac ttaagcagga aacggaggtg gagctgtaca acgaatttcc tgaacctatc aaactggaca agaatgaccg ggccaaggcc tcggcagaaa gctgcagttg ctga SEQ ID NO:170 MTSRKKVLLKVIILGDSGVGKTSLMNQYVNKKFSNQYKATIGADFLTKEVMVDDRLVTMQIWDTAGQ ERFQSLGVAFYRGADCCVLVFDVTAPNTFKTLDSWRDEFLIQASPRDPENFPFVVLGNKIDLENRQV ATKRAQAWCYSKNNIPYFETSAKEAIVEQAFQTIARNALKQETEVELYNEFPEPIKLDKNDRAKASA ESCSC SEQ ID NO:171 atgcactcag atgaaatgat ttatgatgat gttgagaatg gggatgaagg tggaaacagc tccttggaat acggatggag ttcgagtgaa tttgaaagtt acgaagagca gagtgactcg gagtgcaaga atgggattcc caggtccttc ctgcgcagca accacaaaaa gcaactttct catgacctaa cccgtttaaa ggagcactat gagaaaaaga tgagagattt gatggcaagc acggtgggcg tggtggagat tcagcagctc aggcagaagc atgaactgaa gatgcagaag ctcgtgaagg ccgcgaagga cggcaccaag gacgggctgg agaggaccag ggcagccgtg aagaggggcc gctccttcat caggaccaag tctctcatcg cacaggatca cagatcttct cttgaggaag aacagaattt gttcattgat gttgactgca agcacccgga agccatcttg accccgatgc ccgagggttt atctcagcag caggttgtaa gaagatatat actgggttca gttgtcgaca gtgaaaagaa ctacgtagat gctcttaaga ggattttgga gcaatatgag aagccgctgt ctgagatgga gccaaaggtt ctgagtgaga ggaagctgaa gacggtgttc taccgagtca aagagatcct gcagtgccac tcgctatttc agatcgcgct ggccagccgc gtttccgagt gggactccgt ggaaatgata ggcgatgtct tcgtggcttc gttttctaag tccatggtgc tggatgcata cagtgaatat gtgaacaatt tcagcacagc cgtggcagtc ctcaagaaaa catgtgccac aaagcccgct tttcttgaat ttttaaagca ggaacaggag gccagccccg atcgaaccac gctctacagc ctgatgatga agcccatcca gaggttccca cagttcatcc tcctgctcca ggacatgctg aagaacacct ccaaaggcca ccccgacagg ctgcctcttc agatggccct gacagagctc gaaacactag cagagaagtt aaatgaaaga aagagagatg ctqatcaacg ctgtgaagtg aagcaaatag ccaaagccat aaacgaaaga tacctgaaca agcttctcag cagtggaagc cgatacctca ttcgatcaga tgatatgata gaaacagttt acaacgacag aggagagatt gttaaaacca aagaacgccg agtcttcatg ttaaatgatg tgttaatgtg tgccaccgtc agctcacgcc cctctcatga cagccgtgtg atgagcagcc agaggtactt gctgaagtgg agcgttccac tgggacatgt ggacgccatc gagtatggca gcagcgcagg cacgggcgag cacagcaggc accttgccgt tcacccgccg gagagcctgg ccgtggttgc taacgcgaaa ccaaacaaag tttacatggg gccaggacaa ctgtatcaag atttacaaaa cttgttgcat gacttaaatg taattggcca aatcactcag ctgataggaa accttaaagg aaactatcag aacttaaacc agtcagtagc ccatgactgg acatcaggtt tacaaaggct tattttgaag aaagaagatg aaatcagagc tgcggactgc tgcagaattc agttacagct tcccgggaag caggacaaat ctgggcgacc gacgttcttt acagctgtgt tcaatacgtt cacccctgcc atcaaggagt cctgggtcaa cagcttacag atggccaagc tcgccctaga agaggagaac cacatgggct ggttctgtgt ggaagacgat gggaatcaca ttaaaaagga gaagcatcct ctcctcgtcg gacacatgcc cgtgatggtg gccaagcagc aggagttcaa gattgaatgt gctgcttata accctgaacc ttacctaaat aatgaaagcc agccagattc attttccacg gcacatggtt tcctgtggat cggaagttgc acccatcaaa tgggtcagat tgccatcgtc tcgtttcaaa attccactcc caaagtcatt gagtgcttca acgtggaatc tcgcatcctg tgcatgctgt acgttcccgt cgaggagaag cgcagagagc ctggggcacc cccggacccc gagaccccgg ccgtgagagc ttctgatgtc cccacgatct gtgtagggac ggaggaggga agcatttcca tttataaaag cagtcaaggc tccaagaaag tgagacttca gcactttttc actcctgaga agtccacagt catgagcctg gcttgcacgt ctcagagcct gtacgctggc ctggtcaacg gggcagtcgc cagctacgcc agagccccag atggatcctg ggattcagaa cctcaaaaag tgatcaagtt aggcgtccta ccagttagaa gtctactcat gatggaagac acgttgtggg cggcttccgg aggtcaagtc ttcatcatca gtgtggagac tcatgctgta gagggtcagc tggaggccca ccaggaggaa ggcatggtga tctcccacat ggccgtgtcc ggcgtcggga tctggattgc cttcacctca gggtccacgc tccgcctttt tcacacggaa actctcaagc acctgcagga catcaacatc gccacccctg ttcacaacat gctgccaggg caccagcggc tgtcggtgac gagcctgctc gtctgccacg gattgctgat ggtcggcacc agcctgggag tcctcgtggc cctgccggtc ccacgtctgc aagggattcc caaagtgacc ggaagaggca tggtctccta ccatgcacac aacagtcctg tcaaattcat cgtcctggcc acggctctgc acgagaaaga caaggacaaa tccagggaca gcctggctcc tggccccgag cctcaggacg aagaccagaa ggacgcactt ccgagtggag gagctggttc atctctgagc cagggtgacc ctgacgcagc catctggttg ggagattcgc tgggatcgat gactcagaaa agcgacctgt cctcctcatc tgggtccctg agcttgtctc acggctccag ctctctagag cacagatcag aggacagcac catctatgat ctcctgaagg atcctgtctc gctgagaagc aaagcacgcc gggccaagaa agccaaggcc agctcggcgc tggtggtctg tggagggcag ggccaccgcc gggtgcacag gaaggcccgg cagccccacc aggaagagct ggcgccgacc gtcatggtct ggcagatccc tctgctgaat atataa SEQ ID NO:172 MHSDEMIYDDVENGDEGGNSSLEYGWSSSEFESYEEQSDSECKNGIPRSFLRSNHKKQLSHD LTRLKEHYEKKMRDLMASTVGVVEIQQLRQKHELKMQKLVKAAKDGTKDGLERTRAAVK RGRSFIRTKSLIAQDHRSSLEEEQNLFIDVDCKHPEAILTPMPEGLSQQQVVRRYILGSVVDSE KNYVDALKRILEQYEKPLSEMEPKVLSERKLKTVFYRVKEILQCHSLFQIALASRVSEWDSV EMIGDVFVASFSKSMVLDAYSEYVNNFSTAVAVLKKTCATKPAFLEFLKQEQEASPDRTTLY SLMMKPIQRFPQFILLLQDMLKNTSKGHPDRLPLQMALTELETLAEKLNERKRDADQRCEV KQIAKAINERYLNKLLSSGSRYLIRSDDMIETVYNDRGEIVKTKERRVFMLNDVLMCATVSS RPSHDSRVMSSQRYLLKWSVPLGHVDAIEYGSSAGTGEHSRHLAVHPPESLAVVANAKPNK VYMGPGQLYQDLQNLLHDLNVIGQITQLIGNLKGNYQNLNQSVAHDWTSGLQRLILKKEDE IRAADCCRIQLQLPGKQDKSGRPTFFTAVFNTFTPAIKESWVNSLQMAKLALEEENHMGWFC VEDDGNHIKKEKHPLLVGHMPVMVAKQQEFKIECAAYNPEPYLNNESQPDSFSTAHGFLWI GSCTHQMGQIAIVSFQNSTPKVIECFNVESRILCMLYVPVEEKRREPGAPPDPETPAVRASDV PTICVGTEEGSISIYKSSQGSKKVRLQHFFTPEKSTVMSLACTSQSLYAGLVNGAVASYARAP DGSWDSEPQKVIKLGVLPVRSLLMMEDTLWAASGGQVFIISVETHAVEGQLEAHQEEGMVI SHMAVSGVGIWIAFTSGSTLRLFHTETLKHLQDINIATPVHNMLPGHQRLSVTSLLVCHGLL MVGTSLGVLVALPVPRLQGIPKVTGRGMVSYHAHNSPVKFIVLATALHEKDKDKSRDSLAP GPEPQDEDQKDALPSGGAGSSLSQGDPDAAIWLGDSLGSMTQKSDLSSSSGSLSLSHGSSSLE HRSEDSTIYDLLKDPVSLRSKARRAKKAKASSALVVCGGQGHRRVHRKARQPHQEELAPTV MVWQIPLLNI
REFERENCES
[0000]
1. De Jonghe P., Timmerman V., and Nelis E. Hereditary Peripheral Neuropathies in Neuromuscular Diseases: From Basic Mechanisms to Clinical Management 128-146. Karger, Base! (2000).
2. Auer-Grumbach M. at al. Autosomal dominant inherited neuropathies with prominent sensory loss and mutilations: a review. Arch. Neurol. (2003) 60(3):329-34.
3. Auer-Grumbach M., Wagner K., Timmerman V., De Jonghe P. and Hartung H. P. Ulcero-mutilating neuropathy in an Austrian kinship without linkage to hereditary motor and sensory neuropathy IIB and hereditary sensory neuropathy I loci. Neurology 54, 45-52 (2000).
4. Bellone E. et al. A family with autosomal dominant mutilating neuropathy not linked to either Charcot-Marie-Tooth disease type 2B (CMT2B) or hereditary sensory neuropathy type I (HSN I) loci. Neuromuscul. Disord. 12, 286-291 (2002).
5. Dawkins J. L., Hulme D. J., Brahmbhatt S. B., Auer-Grumbach M. and Nicholson G. A. Mutations in SPTLC1, encoding serine palmitoyltransferase, long chain base subunit-1, cause hereditary sensory neuropathy type I. Nat. Genet. 27, 309-312 (2001).
6. Bejaoui K. et al. SPTLC1 is mutated in hereditary sensory neuropathy, type 1. Nat. Genet. 27, 261-262 (2001).
7. Kwon J. M. et al. Assignment of a second Charcot-Marie-Tooth type II locus to chromosome 3q. Am. J. Hum. Genet. 57, 853-858 (1995).
8. De Jonghe P. et al. Mutilating neuropathic ulcerations in a chromosome 3q13-q22 linked Charcot-Marie-Tooth disease type 2B family. J. Neurol. Neurosurg. Psychiatry 62, 570-573 (1997).
9. Auer-Grumbach M. et al. Phenotype-genotype correlations in a CMT2B family with refined 3q13-q22 locus. Neurology 55, 1552-1557 (2000).
10. Echard A. et al. Interaction of a Golgi-associated kinesin-like protein with Rab6. Science 279, 580-585 (1998).
11. Nielsen E., Severin F., Backer J. M., Hyman, A. A. and Zerial, M. Rab5 regulates motility of early endosomes on microtubules. Nat. Cell. Biol. 1, 376-382 (1999).
12. Jordens I. et al. The RAB7 effector protein RILP controls lysosomal transport by inducing the recruitment of dynein-dynactin motors. Curr. Biol. 11, 1680-1685 (2001).
13. Cantalupo G., Alifano P., Roberti V., Bruni C. B. and Bucci C. Rab-interacting lysosomal protein (RILP): the RAB7 effector required for transport to lysosomes. EMBO. J. 20, 683-693 (2001).
14. Press B., Feng Y., Hoflack B. and Wandinger-Ness A. Mutant RAB7 causes the accumulation of cathepsin D and cation-independent mannose 6-phosphate receptor in an early endocytic compartment. J. Cell. Biol. 140, 1075-1089 (1998).
15. Lebrand C. et al. Late endosome motility depends on lipids via the small GTPase RAB7. EMBO. J. 21, 1289-1300 (2002).
16. Seabra M. C., Mules E. H. and Hume A. N. Rab GTPases, intracellular traffic and disease. Trends Mol. Med. 8, 23-30 (2002).
17. Tang B. L. Protein trafficking mechanisms associated with neurite outgrowth and polarized sorting in neurons. J. Neurochem. 79, 923-930 (2001).
18. Geppert M., Goda Y., Stevens C. F. and Sudhof T. C. The small GTP-binding protein Rab3A regulates a late step in synaptic vesicle fusion. Nature 387, 810-814 (1997).
19. Eggenschwiler J. T., Espinoza E. and Anderson K. V. Rab23 is an essential negative regulator of the mouse Sonic hedgehog signaling pathway. Nature 412, 194-198 (2001).
20. Elliott J. L., Kwon J. M., Goodfellow P. J. and Yee, W. C. Hereditary motor and sensory neuropathy IIB: Clinical and electrodiagnostic characteristics. Neurology 48, 23-28 (1997). | The present invention relates generally to the field of human genetics. Specifically, the present invention relates to methods and materials used to isolate and detect human peripheral neuropathy causing or predisposing genes, some alleles of which cause peripheral neuropathy. | 2 |
RELATED APPLICATIONS
[0001] The present application claims the benefit of U.S. Provisional Patent Application No. 61/116,131, filed Nov. 19, 2008, which is incorporated herein by reference in its entirety.
FIELD OF THE INVENTION
[0002] The invention relates generally to a merchandising display and dispensing system for display and dispensing articles. In particular, the invention relates to a modular display and dispensing system having a plurality of modules fitted with one another. The invention also relates to a module device for constructing a merchandising display and dispensing system.
BACKGROUND OF THE INVENTION
[0003] Products in relatively small individual packages are often displayed in and sold from merchandise dispensers that dispense the packages to customers one at a time. Such dispensers are especially useful for small cylindrical product packages that would otherwise be difficult to display on a typical store shelf. The manner in which a product is displayed and dispensed can have a significant impact on sales. This is particularly true in “product-rich” environments, such as grocery and drug stores.
[0004] Conventional merchandise dispensers may suffer from certain shortcomings. For example, such dispensers may not display the product in a visually-appealing manner that promotes sales. Conventional dispensers may be difficult and/or inconvenient to reload. Such dispensers may not be amenable to the creation of larger displays by combining a number of separate dispensers.
SUMMARY OF THE INVENTION
[0005] The invention relates to a merchandising display and dispensing system for displaying and dispensing articles, including cylindrical shaped products, such as rolls of tablets, or disk-like confections. The display and dispensing system can be formed with a plurality of modules, which can be fitted together to construct a modular display and dispensing system.
[0006] Each module comprises a left side panel and a right side panel which are fitted together and form a serpentine chute which feeds rolls by gravity to an access tray where a roll can be removed by hand, thus permitting another roll to enter the tray. The front of the module receives a front cover which covers the chute and provides a surface for indicia of contents inside the module. The front cover is preferably hinged at either its bottom or top to permit reloading product in the chute.
[0007] Each module has a rear surface provided with openings for receiving suction cups or hanging on a nail, hook or other mounting device. However it is preferred to mount the modules side-by-side on a base plate by dovetail connections provided on the base plate and the bottoms of the modules. The modules can also be connected to one another vertically by dovetail connections on top of each module, and/or laterally by dovetail connections on the lateral walls of the adjacent modules. Additionally or alternatively, a header can be fitted by dovetail connection across the top row of modules to provide additional retention of the array or rows and columns, as well as additional space for identifying information.
[0008] Each module is fitted together by pins and sockets in a press fit, and may also be glued. However, positive mechanical retention is preferably provided by the various dovetail connections when the modules are assembled in an array of rows and columns on the base plate.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] Other objects and features of the present invention will become apparent from the following detailed description considered in conjunction with the accompanying drawings. It is to be understood, however, that the drawings are designed solely for purposes of illustration and not as a definition of the limits of the invention, for which reference should be made to the appended claims. It should be further understood that the drawings are not necessarily drawn to scale and that, unless otherwise indicated, they are merely intended to conceptually illustrate the structures and procedures described herein. In the drawings:
[0010] FIG. 1 shows perspective views of a single module and a group of modules assembled in a 2×3 array of rows and columns formed according to a first embodiment;
[0011] FIGS. 2A-2H show various views of a left side panel of the module shown in FIG. 1 ;
[0012] FIGS. 3A-3H show various views of a right side panel of the module shown in FIG. 1 ;
[0013] FIGS. 4A-4H show various views of the base of the module shown in FIG. 1 ;
[0014] FIGS. 5A-5H show various views of the cover of the module shown in FIG. 1 ;
[0015] FIGS. 6A-6H show various views of the header of the module shown in FIG. 1 ;
[0016] FIG. 7 shows a perspective view of a single module formed according to a second embodiment;
[0017] FIGS. 8A-8G show various views of a left side panel of the module shown in FIG. 7 ;
[0018] FIGS. 9A-9G show various views of a right side panel of the module shown in FIG. 7 ;
[0019] FIGS. 10A-10H show various views of the cover of the module shown in FIG. 7 ;
[0020] FIGS. 11A-11J show various views of the base of the module shown in FIG. 7 ;
[0021] FIGS. 12A-12J shows various views of the header of the module shown in FIG. 7 ;
[0022] FIG. 13 shows a flowchart of the process steps of assembling a 2×3 array of modules; and
[0023] FIG. 14 shows a flowchart of the process steps of loading the assembled modular array.
DETAILED DESCRIPTION OF THE EMBODIMENTS
[0024] FIG. 1 shows a merchandising display and dispensing system 1 for display and dispensing articles. The display and dispensing system 1 can be formed with a plurality of modules 10 , which are interconnected with one another to form a modular system 1 . In one embodiment, the multiple modules 10 can be formed to be identical so as to provide interchangeability for the modular system 1 . In the example shown in FIG. 1 , the display and dispensing system 1 is shown to have a 2×3 array (two rows and three columns) of modules 10 . One of such modules 10 is separated from the display and dispensing system 1 and shown side-by-side with the same. Detailed description of such modules 10 will be provided below.
[0025] The modules 10 each comprise a left side panel 12 L and a right side panel 12 R, which are formed so that each of them is substantially a mirror image of the other. FIGS. 2 and 3 show various views of the respective left and right side panels 12 L, 12 R. As the left and right side panels 12 L, 12 R are formed to be substantially mirror images, one the left side panel 12 L will be described in great details.
[0026] The left side panel 12 L include first and second guide rails 14 L, 16 L extending from an inside surface of the left panel 12 L and substantially perpendicularly thereto. The first and second guide rails 14 L, 16 L form a serpentine passage 18 L therebetween. Each lap of the serpentine passage 18 L is inclined downward, allowing articles to be dispensed in the assembled module 10 by gravity when the assembled module 10 is in a working position as shown in both perspective and right-side plane views of FIGS. 2A-2H .
[0027] In the example shown in FIGS. 2A-2H , the serpentine passage 18 opens at the front top portion of the left side panel 12 L, declines towards the rear portion of the left panel 12 L, turns and declines toward the front portion, turns and declines toward the rear portion a second time, and then turns towards the front bottom portion of the left panel 12 L. In such a case, the two ends 20 in , 20 out of the serpentine passage 18 L both open at the front side of the left panel 12 L. In the alternative, the serpentine passage 18 L can open at both the front and rear portions of the panel 12 L. In one example not shown, one end of the serpentine passage 18 L can open at the rear top portion of the panel 12 L. In such an example, articles are to be loaded into the module 10 from the rear thereof.
[0028] The first and second guide rails 14 L, 16 L can incline at different inclination angles. For example, each leg of the first and second guide rails 14 L, 16 L is inclined at an angle from about 10° to about 15° in relation to a horizontal direction. In one example, the inclination angle is about 11°. The inclination angle can be determined by a number factors including the weight of the articles to be dispensed, the material of the articles, the material of the guide rails 14 L, 16 L, and other factors.
[0029] Additionally or alternatively, the serpentine passage 18 L can be formed to have various numbers of turns. In the example of FIGS. 2A-2H , the serpentine passage 18 L is shown to have three turns. The first and second guide rails 14 L, 16 L of the left panel 12 L can also be formed to provide a different number of turns.
[0030] The left panel 12 L can be formed with one or more of top, rear, and bottom panels 22 L, 24 L, 26 L. In the example shown in FIGS. 2A-2H , the top, rear, and bottom panels 22 L, 24 L, 26 L and the left side panel 12 L define a substantially rectangular shape of a module 10 , after the left side panel 12 L is assembled with a corresponding right side panel 12 R (see, FIGS. 3A-3H ). In an example not shown, the top, rear, and bottom panels 22 L, 24 L, 26 L can assume various shapes for enhanced display effects.
[0031] The left and right side panels 12 L, 12 R each can be formed with various additional structures for various purposes. For example, the side panels 12 L, 12 R can be formed with fasteners 28 L, 28 R so that the side panels 12 L, 12 R can be joined with each other to form a module 10 (see, FIG. 1 ). For example, complementary fasteners, such as press-fit fasteners, can be formed on the left and right side panels 12 L, 12 R as are shown in their perspective views in FIGS. 2 and 3 . When the complementary fastener are made to engage with one another, they connect the left and right side panels 12 L, 12 R to each other to result in a module 10 . In an example, the fasteners 28 L, 28 R can be releasably connected to one another, allowing the left and right side panels 12 L, 12 R to be assembled and disassembled repeatedly.
[0032] In another example, the bottom panels 26 L, 26 R of the side panels 12 L, 12 R can be formed with forward extending lips 30 L, 30 R, respectively, to form an access tray 32 for receiving a dispensed product. The forward extending lips 30 L, 30 R each continue to extend upward and form a barrier 34 L, 34 R to retain the dispensed product in position and prevent the same from accidentally falling off the receiving tray 32 . The dispensed product can thus be readily accessed by a user.
[0033] Additionally or alternatively, various connecting structures can be formed on the side panels 12 L, 12 R and adapted to join the module 10 to a front cover (see FIGS. 4A-4H ), to another adjacent module 10 , to a module base (see FIGS. 5A-5H ), and/or to a module header (see FIGS. 6A-6H ) as will be described below in connection with these additional components of the display and dispensing system 1 .
[0034] The module 10 shown in FIGS. 2A-2H can be assembled by bringing and fastening the left and right side panels 12 L, 12 R to each other. For example, the side panels 12 L, 12 R are joined with each other by the fasteners 28 L, 28 R formed on such side panels 12 L, 12 R. In the resulting module 10 , the respective guiding rails of the left and right side panels 12 L, 12 R are aligned to form a serpentine chute 18 inside the module 10 . For example, the first guide rails 14 L, 14 R are aligned to each other and form a continuous front guide 14 . The second guide rails 16 L, 16 R are aligned with each other to form a continuous rear guide 16 . A serpentine chute 36 is formed between the front and rear guides 14 , 16 and extends similarly to the serpentine passage 18 L described above.
[0035] In one example, the first guide rails 14 L, 14 R are spaced from each other as the height of such guide rails 14 L, 14 R is less than that of the top, rear, bottom panels 22 L, 22 R, 24 L, 24 R, 26 L, 26 R as illustrated in the perspective views of the side panels 12 L, 12 R in FIGS. 2 and 3 . The space between the first guide rails 14 L, 14 R is designed to be less than the lesser dimension of the article to be dispensed to avoid such article to fall through the space.
[0036] When the module 10 is set up for operation in a working position as shown in FIG. 1 , the serpentine chute 36 (see FIGS. 2A-2H ) can assist to feed rolls by gravity to the access tray 32 . The dispensed articles can then be removed by a user. When the dispensed article is removed, another article can be dispensed by gravity and enter the access tray 32 .
[0037] FIGS. 4A-4H show a front cover 40 provided for covering the front of the module 10 and the front and rear guides 14 , 16 inside the module 10 . The front cover 40 can assume a shape corresponding the shape of the front portions of the left and right side panels 12 L, 12 R. In the example shown in FIGS. 4A-4H , the front cover 40 have a curved profile formed in accordance with the curvature of the front portions of the side panels 12 L, 12 R. One skilled in the art will appreciate that the front cover can assume various other shapes, such as a straight or wavy surface (not shown).
[0038] The front cover 40 of each module 10 can be formed to provide indicia of the content in the module 10 . For example, the front cover 40 can be provided with a transparent window or opening 42 to allow viewing of the products contained in the module 10 . Additionally or alternatively, the front cover 40 can provide a surface for indicia of products. In one example, the front cover 40 can be made of a transparent material allowing product indicia, such as a product label, to be placed on the inside of the front cover 40 and face outside toward the user. In the alternative, the front cover 40 can be formed so that product information can be affixed on the outside surface of front cover 40 . One skilled in the art will appreciate that the product information can be affixed to the front cover 40 by various other methods.
[0039] The front cover 40 can be attached to the remaining portion of the module 10 by any of various ways. In a preferred embodiment, the front cover 40 is hinged to the bottom portions of the left and right panels 12 L, 12 R in the module 10 to permit the front cover 40 to pivot open, such as when reloading products in the top of the chute 36 . In the example shown in FIGS. 4A-4H , the front cover 40 is formed with a pair of pivoting pins 44 L, 44 R extending from the bottom edges of the front cover 40 . The pivoting pins 44 L, 44 R are adapted to engage and pivot inside corresponding retaining apertures 46 L, 46 R in the left and right side panels 12 L, 12 R, respectively (see FIGS. 2 and 3 ).
[0040] The front cover 40 can also be formed with a pair of locking pins 48 L, 48 R extending from the top edges of the front cover 40 . The locking pins 48 L, 48 R are adapted to be received in corresponding latching openings 50 L, 50 R in the left and right side panels 12 L, 12 R. As is shown in FIGS. 2 and 3 , the latching openings 50 L, 50 R in the side panels 12 L, 12 R each are surrounded by a upward extending stopper 52 L, 52 R for maintaining the front cover 40 in a closed position and preventing the front cover 40 from opening by accident.
[0041] During operation of the front cover 40 , the front cover 40 is either lifted out of or dropped in the latching openings 50 L, 50 R in the left and right side panels 12 L, 12 R. To facilitate such opening and closing operation of the front cover 40 , the retaining apertures 46 L, 46 R in the left and right side panels 12 L, 12 R can be have an oblong shape, as is shown in FIGS. 2 and 3 . The oblong shaped retaining apertures 46 L, 46 R allow cylindrical pivoting pins 44 L, 44 R and in turn the front cover 40 to move slightly in a vertical direction.
[0042] In the embodiment shown in FIG. 1 , multiple modules 10 can be assembled together to form a modular display and dispensing system 1 . For example, the modules 10 can be stacked to form multiple rows or joined side-by-side to form multiple columns. For example, each module 10 can be formed with a convex joint element 54 vex on the top to connect with a concave joint element 54 cav on the bottom of another module 10 . In one example, the modules 10 are each formed with a convex joint element 54 vex on the top surface and a concave joint element 54 cav on the bottom surface. Such modules 10 can be interchanged and interconnected to form a modular system 1 .
[0043] Additionally or alternatively, each module 10 can be formed with a convex joint element 56 vex on one side surface to connect with a concave joint element 56 cav on an opposite side of another module 10 . In one example, the modules 10 each can be formed with a dovetail joint element on each of the top, bottom, and side surfaces of the module 10 to join with a complementary dovetail joint element in an adjacent module.
[0044] FIGS. 5A-5H show a base plate 60 formed to provide additional retention to modules 10 supported thereon. The base plate 60 has a bottom side 62 to be situated on a supporting structure, such as a shelf, countertop or tabletop at the point of purchase. On the top surface 64 of the base plate 60 , a number of joint elements 66 a , 66 b , 66 c are formed, which are complementary to the joint members on the bottom of the modules 10 . In one example, the joint elements 66 a , 66 b , 66 c on the base plate 60 are dovetail joint elements. As one of the perspective views in FIGS. 5A-5H shows, the base plate 60 can be formed with a hollow interior 68 on the bottom side 62 . In one example, a rib 70 is formed inside the hollow interior 68 to provide stability for the base plate 60 .
[0045] The base plate 60 can have an extension 72 extending beyond the assembled modules 10 in the front side. Such an extension 72 can prevent the stacked modules 10 from tipping forward and thus afford additional stability to the display and dispensing system 1 . In one example, the extension 72 is provided with indicia 74 (see FIG. 1 ) for the products contained in the modules 10 and/or the entire display and dispensing system 1 .
[0046] FIGS. 6A-6H shows a header 80 , which can be used together with the modules 10 in a display and dispensing system 1 . In the example shown in FIGS. 6A-6H , the header 80 has an elongated shape with an L-shaped cross-section. The header 80 has a joining plate 82 formed to be connected to the joint elements on the top of modules 10 . In one example, the joining plate 82 is formed with a plurality of cut-outs 84 each to be connected to a complementary dovetail joint element formed on top of the module 10 .
[0047] The front plate 86 of the header 80 extends upward from the joining plate 82 . Similar to the front covers 40 , the front plate 86 can provide a surface 88 for indicia of products in the modules 10 and/or the entire display and dispensing system 1 . In another example not shown, the front plate can be formed in various configurations to promote the products contained in the modules. For example, the front plate can be formed to have the same shape of the products, such as one or more two-dimensional or three-dimensional soda cans for a soda display and dispensing system.
[0048] The various components of the module 10 can be formed of any of various materials. For example, one or more of the side panels 12 L, 12 R including top, rear, and bottom panels 22 L, 22 R, 24 L, 24 R, 26 L, 26 R, the front cover 40 , the base plate 60 , and the header 80 can be made of a plastic material through a molding process.
[0049] FIGS. 7 to 10 show a second embodiment of a module 110 similar the module 10 described above. Similar components and elements of the modules 10 , 110 are formed of similar reference numerals with the same last two digits. Only differences between the two modules 110 , 10 are elaborated below.
[0050] As FIGS. 8A-8G and 9 A- 9 G show, the left and right side panels 112 L, 112 R are each formed with a third guide rail 117 L, 117 R continuously following along the serpentine passage 118 L. The third guide rails 117 L, 117 R have a smaller height dimension compared to that of the first and second guide rails 114 L, 116 L, as is shown in the front side views of FIGS. 8A-8G and 9 A- 9 G. The third guide rail 117 L, 117 R provide additional guidance to the products being dispensed along the serpentine passage 118 L. Additionally or alternatively, the third guide rail 117 L, 117 R space the products away from the inside surfaces of the left and right side panels 112 L, 112 R and thus minimize the possibility of the products being jammed inside the serpentine chute 118 .
[0051] In another example shown in FIGS. 8A-8G and 9 A- 9 G, the first guide rails 114 L, 114 R are each provided with a supporting pin 190 L, 190 R located near the inlet of the serpentine chute 118 and facing toward each other. The supporting pins 190 L, 190 R operate to support a loading guide when loading articles into the module 110 , as will be described below.
[0052] FIGS. 10A-10H show the front cover 140 of the second embodiment, in which a loading guide 192 is provided extending from the inside of the front cover 140 . When the front cover 140 is in an opened position, the loading guide 192 exits from inside of the module 10 and extends in a substantially the same inclined direction as the upper leg of the front guide 114 . The loading guide 192 is thus accessible by a user to load items onto the loading guide 192 . When the front cover 140 is moved toward the closed position, as is shown in the side view in FIGS. 10A-10H , the loading guide 192 retreats into the module 10 . During the retreat, the loading guide 192 inclines further downward to unload the items onto the serpentine front guide 114 by gravity.
[0053] In one embodiment, the loading guide 192 is formed with a tip portion 194 , which is narrower than the remaining portion of the loading guide 192 . During a loading operation, the narrowed tip portion 194 can fit between the first guide rails 114 L, 114 R formed in the left and right side panels 112 L, 112 R, respectively, and form a substantially continuous loading surface extending from the loading guide 192 to the front guide 114 (see FIG. 14 ). In a preferred embodiment, the tip portion 194 has a hook-like structure 196 formed on the lower surface of the tip portion 194 . The hook-like structure 196 is adapted to engage with a pair of supporting pins 190 L, 190 R formed on the first guide rails 114 L, 114 R so as to support the front cover 140 in an open position during a loading operation.
[0054] The front cover 140 can also be provided with a pulling tab 198 to assist a user in opening the front cover 140 . In the example shown in FIGS. 10A-10H , the pulling tab 198 can be formed to extend from the top of the front cover 140 and opposite from the loading guide 192 .
[0055] FIGS. 11A-11J show the base plate 160 of the second embodiment. The base plate 160 can be formed to support two, three, or more modules 10 , 110 . In the example of the two-module base plate 160 (see right side of the drawing), the base plate 160 can have one or more joint elements 167 vex formed on one of the side surface to connect with complementary joint elements 167 cav formed on an opposite side surface of another base plate 160 . For example, convex and concave joint elements 167 vex , 167 cav are formed respectively at the left and right side surfaces of the base plate 160 . Such a base plate 160 can be joined to another base plate 160 to form an expanded modular display and dispensing system 101 (see FIG. 13 ). In one example, the joint elements 167 vex , 167 cav on the side surfaces of the base plate are dovetail joint elements. In another example, the concave joint elements 167 cav can be in the form of cut-outs formed in the side walls of the base plate 160 .
[0056] FIGS. 12A-12J show a header 180 similar to that shown in FIGS. 6A-6H .
[0057] FIG. 13 shows a flowchart of the process of assembling a 2×3 array of modules 110 . Steps 1 and 2 in FIG. 13 indicate that the bottom row of modules 120 are attached to a base plate 160 . During steps 1 and 2 , each of the modules 110 in the bottom row is dovetailed to the base plate 160 and to the adjacent module(s) 110 . Step 3 indicates that the top row modules are then attached to the bottom row modules by the dovetail joint elements on the respective modules 110 . In Step 4 , the header 180 is assembled, resulting in a final modular display and dispensing system 101 .
[0058] The above assembling steps can be carried out at the point of purchase, such as a store. In such a case, the assembled modular display and dispensing system 101 is ready for loading the products as described below in connection with FIG. 14 . Alternative, the assembling steps 1 - 4 can be carried out by the manufacturer. In such a case, the assembled modular display and dispensing system 101 can be packed in a shipping carton, as indicated in step 5 , to be delivered to customers. Optionally, the products to be dispensed can be packed and shipped to the customers at the same time.
[0059] FIG. 14 shows a flowchart of the process of loading the modular array of FIG. 13 . To open the front cover 140 , lift the front cover 140 to unlatch the locking pins 148 L, 148 R on the front cover 140 as indicated in step 1 of the opening operation. Then, engage the hook-like structure 196 on the loading guide 192 with the supporting pins 190 L, 190 R on the left and right first guide rails 114 L, 114 R, as indicated in step 2 of the opening operation. The loading guide 192 thus extends the front guide 114 outside the module 110 for easier access by a user. For example, products can be placed onto the loading guide 192 , which leads the products onto the front guide 114 .
[0060] After the loading operation is completed, the loading guide 192 is unhooked from the supporting pins 190 L, 190 R. The front cover 140 can then be closed. When the locking pin 148 L, 148 R on the front cover 140 reaches the latching opening 150 L, 150 R on the side panels 112 L, 112 R, the front cover 140 is lifted to allow the locking pins 148 L, 148 R to be retained in position in the latching opening 150 L, 150 R.
[0061] The loaded display and dispensing system 101 is ready for use. In one example, the display and dispensing system 101 can be placed in a highly visible location in the store, such as by a cash register.
[0062] While there have shown and described and pointed out fundamental novel features of the invention as applied to a preferred embodiment thereof, it will be understood that various omissions and substitutions and changes in the form and details of the devices illustrated, and in their operation, can be made by those skilled in the art without departing from the spirit of the invention. For example, it is expressly intended that all combinations of those elements and/or method steps which perform substantially the same function in substantially the same way to achieve the same results are within the scope of the invention. Moreover, it should be recognized that structures and/or elements and/or method steps shown and/or described in connection with any disclosed form or embodiment of the invention can be incorporated in any other disclosed or described or suggested form or embodiment as a general matter of design choice. It is the intention, therefore, to be limited only as indicated by the scope of the claims appended hereto. | A merchandising display and dispensing system for displaying and dispensing articles, including cylindrical shaped articles or rolls of disk-shaped articles. In particular, the invention relates to a modular display and dispensing system having a plurality of modules fitted with one another. Each module comprises a left side panel and a right side panel which are fitted together and form a serpentine chute which feeds articles by gravity to an access tray where an article can be removed by hand, thus permitting another article to enter the tray. The front of the module receives a front cover for covering the chute and provides a surface for indicia of contents inside the module. The front cover is preferably hinged at the bottom to permit reloading product in the top of the chute. Various connecting structures can be formed on the side panels and adapted to join the module to a front cover, to another adjacent module, to a module base, and/or to a module header to form a modular display and dispensing system. | 0 |
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims priority to Provisional Application Serial No. 60/419,992, filed on Oct. 21, 2002.
BACKGROUND OF THE INVENTION
[0002] In certain offshore applications, keel guides are mounted to various vessels or platforms to guide risers extending to subsea locations. The keel guides restrain the upper end of the risers against lateral motion, thus preventing the risers from interfering with each other or with the vessel or platform. Generally, a keel guide comprises a cylindrical member or “can” which is attached to the hull of the vessel or platform with an appropriate bracket.
[0003] Risers are permitted to move vertically within the keel guide to compensate for motion of the vessel or platform. Each riser is equipped with a keel joint designed to ride within the keel guide. Generally, the keel joint comprises a pipe section of increased thickness to withstand the bending loads exerted on the joint by the keel guide. The keel joint may be provided with an outer wear sleeve along the portion of the joint which contacts the keel guide.
[0004] In many applications, a tieback connector is coupled to a lower end of the riser and moved to the seabed as the riser is lowered. However, such connectors may tend to be too large to pass through the keel guide of nominal size. Accordingly, the riser is run outside of or offset from the keel guide and moved into the keel guide in a later procedure. In some applications, for example, the keel guide is formed with a slot, and once the connector has passed the keel guide, the vessel or platform is translated toward the riser until the riser passes through the slot and into the keel guide. The riser is then moved vertically until the keel joint enters the keel guide. The outer diameter of the keel joint is larger than the width of the slot to restrain the keel joint within the keel guide.
[0005] In some applications, the riser is lowered until the tieback connector is below the keel guide. At this point, the vessel or platform is translated, until the riser moves through the slot in the keel guide. The riser is then lowered and positioned until the keel joint is within the keel guide, the riser is tensioned and the keel joint remains positioned in the keel guide.
[0006] Translation of the vessel or platform to the riser coupled with subsequent movement of the keel joint into the keel guide is a costly and time-consuming process. Additionally, such an approach typically requires the cutting of a slot into the platform structure of sufficient width to permit the passing of the riser from a position external to the keel guide to a position within the keel guide.
SUMMARY
[0007] The present invention relates generally to a technique for guiding a riser in an offshore environment. The technique utilizes a bushing assembly that may be selectively landed within a keel guide. The bushing assembly also comprises an opening sufficient to permit relative linear movement of the riser therethrough. The bushing assembly allows the use of a keel guide with a larger diameter, e.g. sufficient to permit the passing of a tieback connector, while still guiding linear movement of the riser within the keel guide.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] Certain exemplary embodiments of the invention will hereafter be described with reference to the accompanying drawings, wherein like reference numerals denote like elements, and:
[0009] [0009]FIG. 1 is a front elevational view of a riser being installed in a keel guide, according to an embodiment of the present invention;
[0010] [0010]FIG. 2 is a top view of a keel guide, according to one embodiment of the present invention;
[0011] [0011]FIG. 3 is a cross-sectional view taken generally along line 3 - 3 of FIG. 2;
[0012] [0012]FIG. 4 is a partial cross-sectional view taken generally along line 4 - 4 of FIG. 2;
[0013] [0013]FIG. 5 illustrates one embodiment of a bushing being installed in a keel guide;
[0014] [0014]FIG. 6 is a cross-sectional view taken generally along line 6 - 6 of FIG. 5;
[0015] [0015]FIG. 7 is a top view of an embodiment utilizing several keel guides arranged on a hull;
[0016] [0016]FIG. 8 is a top view of another embodiment of a keel guide having retractable pins for retaining a bushing;
[0017] [0017]FIG. 9 is a side cross-sectional view taken generally along line 9 - 9 of FIG. 8;
[0018] [0018]FIG. 10 illustrates a guide bushing being installed in a keel guide as illustrated in FIG. 8;
[0019] [0019]FIG. 11 is a cross-sectional view of a plumb mounted lock-down pin assembly taken generally along line 11 - 11 of FIG. 9;
[0020] [0020]FIG. 12 is a cross-sectional view similar to FIG. 11, but showing an obliquely mounted lock-down pin assembly;
[0021] [0021]FIG. 13 is a top view of a plurality of keel guides of the type illustrated in FIG. 8, arranged on a hull;
[0022] [0022]FIG. 14 is a side cross-sectional view of another embodiment of a keel guide having spring-loaded retaining pins;
[0023] [0023]FIG. 15 is a side view of the guide bushing illustrated in FIG. 14 being installed in a keel guide;
[0024] [0024]FIG. 16 is an expanded view of a spring-loaded retaining pin illustrated in FIG. 15;
[0025] [0025]FIG. 17 is a side cross-sectional view of another embodiment of a bushing disposed within a keel guide;
[0026] [0026]FIG. 18 is a cross-sectional view taken generally along line 18 - 18 of FIG. 17;
[0027] [0027]FIG. 19 is a top view of another embodiment of a keel guide having a lock-down pin assembly;
[0028] [0028]FIG. 20 is a side cross-sectional view taken generally along line 20 - 20 of FIG. 19;
[0029] [0029]FIG. 21 is an expanded view of an embodiment of a lock-down pin assembly illustrated in FIG. 20;
[0030] [0030]FIG. 22 is a cross-sectional view taken generally along line 22 - 22 in FIG. 21;
[0031] [0031]FIG. 23 is a cross-sectional view taken generally along line 23 - 23 in FIG. 21;
[0032] [0032]FIG. 24 is a top view of an embodiment of a keel guide system having a band-type locking device;
[0033] [0033]FIG. 25 is a side partial cross-sectional view of the keel guide system illustrated in FIG. 24;
[0034] [0034]FIG. 26 is a cross-sectional view taken generally along line 26 - 26 of FIG. 25; and
[0035] [0035]FIG. 27 is a cross-sectional view taken generally along line 27 - 27 of FIG. 24.
DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS
[0036] Referring generally to FIG. 1, an exemplary embodiment of a keel guide system 30 is illustrated. Keel guide system 30 comprises a keel guide 32 , a riser assembly 34 and a bushing 36 to be selectively landed in keel guide 32 . In at least one embodiment, riser assembly 34 comprises a keel joint 38 , and bushing 36 is temporarily coupled to riser assembly 34 at or below keel joint 38 . As riser assembly 34 is moved downwardly through keel guide 32 , bushing 36 lands in keel guide 32 and is released from riser assembly 34 to permit keel joint 38 to slide in a linear direction within an opening 39 formed axially through bushing 36 .
[0037] In the embodiment illustrated, keel guide system 30 also comprises a connector 40 , such as a tieback connector. Keel guide 32 is sized to permit the passage of connector 40 as riser assembly 34 is fed downwardly towards the subsea floor. Additionally, keel guide 32 may be attached to a structure 42 which, by way of example, comprises a hull of a vessel or a platform used in an offshore application. Keel guide 32 is attached to the vessel or platform via an appropriate bracket 44 .
[0038] One embodiment of keel guide system 30 is illustrated in FIG. 2. In this embodiment, keel guide 32 is mounted to a vessel or platform by bracket 44 . An inner diameter 46 of keel guide 32 is sufficiently large to allow passage of tieback connector 40 or other component attached to the bottom of riser assembly 34 .
[0039] As illustrated, keel guide 32 comprises a side opening 48 that extends the longitudinal length of keel guide 32 . Side opening 48 allows keel guide 32 to be opened and closed a slight amount to increase or decrease the effective internal diameter 46 of keel guide 32 . A locking device 50 , such as a band-type locking device, is coupled to keel guide 32 to open or close the keel guide 32 .
[0040] One exemplary locking device 50 is illustrated in cross-section in FIG. 3. In this embodiment, locking device 50 comprises a pivot bracket 52 attached to keel guide 32 by, for example, welding or other appropriate fastener, on one side of opening 48 . Pivot bracket 52 comprises a pair of slots 54 for receiving corresponding pins 56 extending from a pivot sleeve 58 .
[0041] A second bracket 60 is attached to keel guide 32 by welding or other appropriate fastener on a side of opening 48 opposite pivot bracket 52 . Second bracket 60 comprises a remote operated vehicle (“ROV”) bucket 62 . A stem 64 is coupled between pivot sleeve 58 and bucket 62 and extends across side opening 48 . Stem 64 may be threadably engaged with pivot sleeve 58 and retained against movement relative to ROV bucket 62 by a shoulder 66 and a retaining ring 68 . Stem 64 further comprises a head 70 that extends into ROV bucket 62 . Head 70 is adapted for engagement and rotation by an ROV manipulator to selectively increase or decrease the width of side opening 48 and thus the diameter 46 of keel guide 32 .
[0042] Referring generally to FIG. 4, in this embodiment, bushing 36 comprises a wear bushing assembly 72 disposed in an annular space between keel guide 32 and keel joint 38 . Wear bushing assembly 72 has a bushing member 74 and a plurality of wear members 76 . Wear members 76 may be attached to bushing member 74 by fasteners, such as screws 78 and are oriented to bear against keel joint 38 , as illustrated. Thus, wear members 76 may be replaced due to, for example, sacrificial wear. In other embodiments, wear members 76 may comprise coatings or other types of hardened surfaces, e.g. hard facing, to reduce the detrimental effects of wear. The coating may be formed of a hardened metal or a nonmetallic material applied to bushing member 74 .
[0043] Bushing 36 is selectively received and held within keel guide 32 by a retention or landing mechanism 80 . An exemplary landing mechanism 80 comprises a landing feature 82 , e.g. a groove, defined by a lower shoulder 84 and an upper shoulder 86 . Bushing member 74 is received in landing feature 82 and is retained against axial movement by lower shoulder 84 and upper shoulder 86 .
[0044] To facilitate landing of bushing 36 in keel guide 32 , bushing 36 may be temporarily attached to riser assembly 34 by a mounting mechanism 88 as illustrated in FIG. 5. One exemplary mounting mechanism 88 comprises a clamp connector 90 which connects wear bushing assembly 72 to riser assembly 34 generally at the junction between keel joint 38 and a next lower riser section 92 . A lower clamp 94 is secured below a flange 96 disposed on lower riser section 92 . An upper clamp 98 is secured above flange 96 on keel joint 38 . Lower clamp 94 is secured to upper clamp 98 by a plurality of tie rods 100 and corresponding fasteners, such as nuts 102 .
[0045] As illustrated in FIG. 6, lower clamp 94 and upper clamp 98 may each comprise semicircular halves 104 and 106 that are secured around riser assembly 34 by one or more appropriate fasteners 108 , such as screws. Clamp connector 90 is secured to wear bushing assembly 72 by posts 110 . In the specific embodiment illustrated, posts 110 extend from wear bushing assembly 72 to upper clamp 98 and are secured to upper clamp 98 by shear pins 112 (see FIG. 5).
[0046] Prior to running riser assembly 34 , the locking device 50 on keel guide 32 is actuated via, for example, an ROV to open keel guide 32 to a position where the inner diameter 46 above landing feature 82 is slightly larger than the outside diameter of bushing 36 . The inside diameter below landing feature 82 remains slightly smaller that the outside diameter of bushing 36 . As bushing 36 is lowered into keel guide 32 , bushing assembly 72 lands on lower shoulder 84 . As the riser assembly 34 is further lowered, the weight of the riser assembly causes the shearing of shear pins 112 . The riser assembly 34 then continues downward and leaves bushing 36 retained in keel guide 32 . Locking device 50 may then be actuated to close keel guide 32 such that upward, linear movement of bushing 36 is prevented by the interfering engagement of upper shoulder 86 with bushing member 74 .
[0047] In an exemplary application, a plurality of keel guides 32 are attached to a structure such as a hull 114 of a vessel or platform, as illustrated in FIG. 7. The locking devices 50 on each keel guide are oriented for accessibility by an ROV. By using bushings 36 in each keel guide 32 , connectors or components can be moved downwardly through the center of each keel guide during installation, and the corresponding keel guides 32 and bushings 36 cooperate to prevent the riser assemblies 34 from interfering with each other or hull 114 upon installation.
[0048] Another embodiment of keel guide system 30 is illustrated in FIGS. 8 through 10. A keel guide 32 ′ is coupled to a structure, such as the hull of a vessel or a platform, via bracket 44 . As described above, the inner diameter of the keel guide is large enough to allow passage of a tieback connector or other component attached to the bottom of riser assembly 34 . In this embodiment, bushing 36 is landed on a shoulder 116 formed along an interior surface 118 of keel guide 32 ′. Interior surface 118 has a slightly greater diameter than the remainder of keel guide 32 ′ to permit bushing 36 to move downwardly to shoulder 116 without the use of an expandable side opening.
[0049] In the embodiment illustrated, wear bushing assembly 72 , and specifically bushing members 74 , is held against shoulder 116 by one or more lock-down assemblies 120 . Lock-down assemblies 120 may be mounted in a variety of orientations, such as the exemplary plumb mounted lock-down assembly 122 and the obliquely mounted assemblies 124 , illustrated best in FIG. 8. Lock-down assemblies 120 may be used selectively to prevent upward linear motion of bushing 36 once landed against shoulder 116 , as illustrated in FIGS. 9 and 10. Specifically, once bushing 36 is landed in keel guide 32 ′, either or both lock-down assemblies 122 and 124 may be actuated by, for example, an ROV to retain bushing 36 against linear motion within keel guide 32 ′. As illustrated best in FIG. 10, a temporary mounting mechanism 88 and corresponding clamp connector 90 may be used to temporarily hold bushing 36 in place with respect to riser assembly 34 while being lowered into keel guide 32 ′.
[0050] Exemplary embodiments of a plumb mounted lock-down assembly 122 and an obliquely mounted lock-down assembly 124 are illustrated in FIGS. 11 and 12, respectively. Each lock-down assembly comprises a sleeve 126 which is attached to keel guide 32 ′ by an appropriate fastening method, such as welding. Each lock-down assembly further comprises an ROV bucket 128 attached to an end of sleeve 126 generally opposite keel guide 32 ′. A lock-down pin 130 is threadably engaged with sleeve 126 at an internal threaded region 132 . A first end 134 of lock-down pin 130 extends into a keel guide opening 136 . As pin 130 is threaded inwardly, the first end 134 moves into the interior of keel guide 32 ′ to prevent upward movement of bushing 36 . In the plumb mounted lock-down assembly 122 , opening 136 is generally radially directed, while opening 136 of obliquely mounted lock-down assembly 124 is oriented at an angle with respect to the radius, as illustrated in FIG. 12. First end 134 may have a variety of configurations, but one exemplary configuration is a conical tip.
[0051] An opposite end 138 of lock-down pin 130 extends into ROV bucket 128 and terminates at a head 140 . Head 140 is adapted for engagement by an external device, such as an ROV manipulator.
[0052] One exemplary application of keel guide system 30 in which keel guide 32 ′ is utilized is illustrated in FIG. 13. In this example, a plurality of keel guides 32 ′ are attached to hull 114 by appropriate brackets 44 . Each of the keel guides comprises a plurality of lock-down assemblies 120 oriented for access by an ROV. Thus, the riser assemblies 34 with attached connectors or other components may be run through corresponding keel guides 32 ′ until each bushing 36 is landed therein. Upon release, e.g. fracturing, of the temporary mounting mechanism 88 , each riser assembly slides linearly downward through its surrounding bushing 36 .
[0053] Another embodiment of keel guide system 30 is illustrated in FIGS. 14 through 16. In this embodiment, a keel guide 32 ″ is coupled to bracket 44 for connection to an appropriate structure, such as the hull of a vessel or platform. As with previously described embodiments, the inner diameter of keel guide 32 ″ may be large enough to allow passage of a connector, such as a tieback connector, or other component attached to the bottom of riser assembly 34 .
[0054] In this embodiment, bushing 36 is landed in a landing feature 142 that is in the form of bowl 144 defined by an upper interior surface of keel guide 32 ″ (see FIG. 15). Bowl 144 is shaped to receive a wear bushing assembly 146 of bushing 36 . Specifically, the exemplary wear bushing assembly 146 comprises one or more radially extending bearing members 148 having interior wear inserts 150 . Wear inserts 150 are positioned to bear against keel joint 38 . Additionally, wear bushing assembly 146 also comprises a plurality of retention members 152 that retain bushing 36 against upward movement within keel guide 32 ″. In other words, the shape of bowl 144 allows wear bushing assembly 146 to move downwardly into keel guide 32 ″ until further movement is blocked by landing feature 142 . Once positioned against landing feature 142 , retention members 152 may be actuated to impede upward movement of bushing 36 , as illustrated in FIG. 14.
[0055] In this embodiment, bushing 36 also may comprise a temporary retention mechanism 154 by which bushing 36 is temporarily coupled to riser assembly 34 during installation of bushing 36 into keel guide 32 ″. One exemplary retention mechanism 154 comprises a clamp connector 156 that may be clamped around riser assembly 34 . Clamp connector 156 is coupled to wear bushing assembly 146 via posts 158 and shear pins 160 . As riser assembly 34 is lowered through the interior of keel guide 32 ″, bushing 36 moves with riser assembly 34 until landed in landing feature 142 . The weight of riser assembly 34 shears shear pins 160 , and riser assembly 34 continues downward movement through keel guide 32 ″ while bushing 36 is retained within the keel guide. Subsequently, retention members 152 may be actuated to impede upward movement of bushing 36 with respect to keel guide 32 ″.
[0056] One exemplary embodiment of retention mechanism 152 is illustrated in FIG. 16. In this embodiment, retention member 152 comprises a plurality of spring-loaded assemblies 162 . Each spring-loaded assembly has a pin that is biased outwardly by a spring 166 . Pin 164 and spring 166 may be mounted in a corresponding bore 168 formed in bearing member or members 148 . Spring 166 biases pin 164 towards a retention groove 170 formed in the interior wall of keel guide 32 ″. Once pin 164 is biased into engagement with groove 170 , upward movement of bushing 36 is inhibited. A retainer, such as a screw 172 , may be used to partially block bore 168 and thereby retain pin 164 within bore 168 .
[0057] As illustrated in FIGS. 17 and 18, an external wear sleeve 174 may be utilized between bushing 36 and keel joint 38 . The wear sleeve 174 may be attached to keel joint 38 by, for example, press fitting, shrink fitting or other suitable techniques. Wear sleeve 174 protects keel joint 38 from wear and damage as keel joint 38 moves within keel guide 32 . In one example, wear sleeve 174 may comprise a radially inward backup ring 176 coupled to an external wear layer 178 by, for example, welding. In this example, backup ring 176 comprises a feature 180 , such as a split in the material. Feature 180 can be engaged with a corresponding feature 182 on keel joint 38 to limit relative movement between keel guide 38 and wear sleeve 174 . Alternatively, backup ring 176 may comprise or may be replaced with a thicker elastomeric material to enable greater flexibility within the keel guide. The thicker elastomeric material may comprise, for example, a poured or castable material, such as a foam.
[0058] Another embodiment of keel guide system 30 is illustrated in FIGS. 19 through 23. In this embodiment, a keel guide 32 ′″ is mounted to a structure, such as the hull of a vessel or platform by a bracket 44 . Again, the inner diameter of keel guide 32 ′″ may be large enough to allow the passage of a connector, such as a tieback connector, or other component attached to the bottom of riser assembly 34 . Bushing 36 is landed within the interior of keel guide 32 ′″ to limit radial movement of riser assembly 34 while allowing relative linear movement between riser assembly 34 and keel guide 32 ′″. Bushing 36 comprises a bushing assembly 184 having at least one and typically a plurality of wear inserts 186 that bear against keel joint 38 of riser assembly 34 . Additionally, a retention mechanism 188 is used to retain bushing 36 within keel guide 32 ′″, as illustrated in FIGS. 19 and 20.
[0059] One exemplary retention mechanism 188 comprises a plurality of swinging lock-down pin assemblies 190 (see FIG. 19). Additionally, a temporary retention mechanism may be used to hold bushing 36 to riser assembly 34 during installation of bushing 36 in keel guide 32 ′″, as with the embodiments described above. In this embodiment, the plurality of pin assemblies 190 , e.g. four pin assemblies, cooperate to restrain bushing 36 against linear movement with respect to keel guide 32 ′″ once the bushing is landed within the keel guide.
[0060] As illustrated in FIGS. 21 through 23, one exemplary type of pin assembly 190 comprises a body 192 having a bore or other type of opening 194 to slidably receive a lock-down pin 196 . Lock-down pin 196 is biased radially outwardly by a spring 198 disposed within bore 194 . Each lock-down pin 196 is retained in its corresponding bore 194 by a retaining screw 200 .
[0061] Pin assemblies 190 may be mounted at a lower region of bushing 36 beneath a wear bushing assembly 202 . Each pin assembly 190 may be coupled to the underside of wear bushing assembly 202 by sets of brackets and pins. For example, a pair of outer brackets 204 are attached to wear bushing assembly 202 at a radially outlying region by, for example, welding or other suitable attachment technique (see FIG. 22). A second set of brackets 206 are similarly attached below wear bushing assembly 202 radially inward from the set of brackets 204 (see FIG. 23). Body 192 is secured to the second, inward set of brackets 206 via a pin 208 . Additionally, body 192 is secured to the first, radially outward set of brackets 204 via shear pins 210 , which are threaded into outer brackets 204 . An undercut 212 is formed, e.g. machined, to an underside of wear bushing assembly 202 proximate each second, radially inward set of brackets 206 .
[0062] During deployment, bushing 36 is run into keel guide 32 ′″ in a manner similar to that of the embodiments described above. When the wear bushing assembly 202 enters keel guide 32 ′″, the outer end of each lock-down pin 196 contacts a tapered surface 214 formed along the interior surface of keel guide 32 ′″. The lock-down pins 196 ride against tapered surface 214 and are cammed inward into their corresponding bores 194 against the biasing force of the corresponding spring 198 . As wear bushing assembly 202 is moved downwardly into keel guide 32 ′″, the lock-down pins 196 are moved past tapered surface 214 and into proximity with a groove 216 . The springs 198 force corresponding lock-down pins 196 outwardly into groove 216 . An upper edge or shoulder 218 that defines the upper extent of groove 216 forms a locking taper with the lock-down pins 196 . This prevents pins 196 from being cammed inward by moderate upwardly directed loads on the bushing 36 .
[0063] If bushing 36 is to be retrieved, riser assembly 34 is raised until the installation clamps, e.g. clamp connector 154 , contacts wear bushing assembly 202 . When sufficient upward force is applied to bushing 36 , shear pins 210 are sheared. This allows each pin assembly 190 to swing about pin 208 so the lock-down pin 196 clears groove 216 . The undercut region 212 formed in wear bushing assembly 202 provides clearance for the pivoting of body 192 . Upon retrieval of bushing 36 , shear pins 210 may be replaced.
[0064] Another embodiment of keel guide system 30 is illustrated in FIGS. 24 through 27. In this embodiment, a keel guide 32 ″″ may be mounted to a structure, such as the hull of a vessel or platform. As with the embodiments described above, the inner diameter of keel guide 32 ″″ may be made large enough to allow passage of a connector, such as a tieback connector, or other component attached to the bottom of riser assembly 34 . In this embodiment, keel guide 32 ″″ has a longitudinal side opening 222 that extends along the length of the keel guide. Side opening 222 allows the diameter of the keel guide to be increased and decreased a small amount by expanding and contracting, respectively, side opening 222 . A locking device 224 , such as a band-type locking device, is used to expand or contract side opening 222 . An exemplary bushing 36 may be designed similar to that described with reference to FIGS. 2 and 5.
[0065] Locking device 224 comprises a first set of brackets 226 and 228 (see FIGS. 26 and 27) that are attached to an exterior of keel joint 32 ″″ by, for example, welding or other suitable attachment technique. The first set of brackets 26 , 28 are located on one side of opening 222 . A first pivot pin 230 is rotatably mounted in brackets 226 , 228 and is retained by a suitable mechanism, such as a washer 232 and a screw 234 .
[0066] A second set of brackets 236 and 238 are attached to the exterior of the keel joint, on a side of opening 222 opposite brackets 226 , 228 , by welding or other suitable technique. A second pivot pin 240 is rotatably mounted in brackets 236 , 238 and is retained by an appropriate mechanism, such as a washer 242 and a screw 244 . The first set of brackets 226 , 228 is provided with notches, such as notches 246 , and the second set of brackets 236 , 238 is provided with comparable notches, such as notches 248 (see FIG. 24). Notches 246 and 248 are designed for engagement by an ROV clamping tool of the type used in subsea operations.
[0067] A stud 250 (see FIGS. 26 and 27) is disposed through a hole 252 in first pivot pin 230 and through a second hole 254 disposed through second pivot pin 240 . The rotation of stud 250 is prevented by, for example, a screw 256 which engages a slot 258 in a head 260 of stud 250 . The other end of stud 250 is threaded into a blind bore 262 of a locking device bushing 264 . After stud 250 is threaded partially into bore 262 , a retaining screw 266 is screwed transversely into the side of stud 250 . Screw 266 prevents inadvertent separation of stud 250 from locking device bushing 264 .
[0068] An open end 268 of locking device bushing 264 is disposed proximate to or bears on pivot pin 240 to prevent further separation of locking device 224 . Opposite open end 268 , locking device bushing 264 is attached to an actuator 270 , such as a T-handle. The T-handle is attached via a fastener, such as a bolt 272 . By way of example, actuator 270 may comprise a cross-bar 274 adapted to be gripped for rotation by an ROV tool.
[0069] To adjust locking device 224 and increase or decrease the effective diameter of the keel guide, notches 246 , 248 are engaged by an ROV, and the two sides of the locking device are squeezed more closely together. Another ROV tool is then utilized to rotate actuator 270 , e.g. a T-handle, to turn bushing 264 relative to stud 250 . Depending on the direction of rotation, the distance between the head of stud 250 and locking device bushing 264 can be increased or decreased. Because the ROV is squeezing the locking device together, the spring force of keel guide 32 ″″ is not bearing on stud 250 and locking device bushing 264 . Accordingly, a smaller amount of torque is required to rotate the locking device bushing 264 .
[0070] Once the bushing 264 has been adjusted as desired, the ROV releases the sides of the locking device 224 , and the keel guide expands to its adjusted diameter. Accordingly, the diameter of the keel guide can be decreased or increased to hold or release the bushing 36 , as described with respect to the embodiment illustrated in FIGS. 2 and 5.
[0071] It should be understood that the foregoing description is of exemplary embodiments of this invention, and that the invention is not limited to the specific forms shown. For example, the keel guide system may be utilized in a variety of environments with a variety of riser assemblies; the size and shape of the keel guide may be adjusted depending on the size and shape of connectors or other components that pass through the keel guide; the configuration of the landing mechanisms, retention mechanisms and locking devices may be changed; and the size and configuration of various components can be adjusted according to a desired application. These and other modifications may be made in the design and arrangement of certain elements without departing from the scope of the invention as expressed in the appended claims. | A technique for guiding a riser in an offshore environment. The technique utilizes a keel guide that permits the passage of connectors or other components therethrough. A bushing is mounted within the keel guide to guide the relative linear motion of the riser assembly through the keel guide. | 4 |
BACKGROUND OF THE INVENTION
The invention relates to universal coupling mechanism for flexible torque-transmitting interconnection of rotatable input and output members, and in particular to such mechanisms which employ meshing gear teeth for torque transmission.
The conventional universal joint has remained essentially the same since its invention by Robert Hooke in 1676. It involves like input and output rotatable coupling members with bifurcated ends which are held in quadrature interlace by a first diametrically extending pin-axis connection of the bifurcated ends of the input member to an intermediate coupling member, and by a second diametrically extending pin-axis connection of the bifurcated ends of the output member to the same intermediate coupling member. Neat as Mr. Hooke's solution was, his coupling is necessarily severely limited as to tolerable degree of angular misalignment of the input and output rotary axes and as to the uniformity with which torque may be transmitted in the course of a single revolution of the coupling. Such limitations remain to this day, for such universal-joint constructions of which I am aware.
SUMMARY OF THE INVENTION
It is an object of the invention to provide an improved universal coupling of the character indicated.
A specific object is to provide such a coupling with inherent utility over a greater range of angular misalignment than heretofore.
Another specific object is to provide inherently greater and better torque-transmitting capability in such a coupling.
A further object is to employ basically simple structure in accomplishing the above objects.
It is also a specific object to meet the above objects with structure which is to an extent modular to thereby enable ganged series-connection of multiple couplings for even greater angular offset of the input and output axes of rotation.
The invention achieves the foregoing and other objects and features by providing rotatable input and output members with coacting formations to retain the same point of intersection of their respective rotary axes while permitting angular flexibility to said axes about said point of intersection. A first plurality of radially outward tooth formations in the radial plane of said point on one of said members meshes with radially inward tooth formations of a corresponding second plurality in the radial plane of said point on the other of said members. The teeth of both pluralities are each right-frusto-conical, each tooth being on a radial axis which intersects said point, and each tooth being geometrically convergent to said point. The meshing teeth which are at any given part of the rotary cycle involved in torque transmission are in or substantially in the geometrical plane (a) which bisects the instantaneous angle between the intersecting input and output axes of rotation and (b) which is normal to the geometrical plane which includes and is therefore defined by said axes of rotation.
DETAILED DESCRIPTION
The invention will be described in detail for various illustrative embodiments, in conjunction with the accompanying drawings, in which:
FIG. 1 is a simplified sectional view of a coupling between rotary axes which are shown to be angularly misaligned about the point of their intersection, the section being taken in the geometrical plane which includes both axes of rotation;
FIG. 2 is an exploded view of the parts of FIG. 1, for the aligned relation of the rotary axes;
FIG. 3 is a sectional view taken at 3--3 in FIG. 2;
FIG. 4 is an inside-end view of one of the parts of FIG. 2, taken from the aspect 4--4 of FIG. 2;
FIG. 5 is a somewhat schematic isometric diagram to illustrate intersecting orbits of tooth elements in the course of rotation of the coupling of FIG. 1;
FIG. 6 is a fragmentary and somewhat schematic diagram to illustrate an instantaneous relation between successive input-member teeth and output-member teeth on both sides of one of their regions of meshing relation;
FIGS. 7 and 8 are views similar to FIG. 1, to show modifications;
FIG. 9 is an exploded view similar to FIG. 2 but applicable to the structure of FIG. 8;
FIG. 10 is a sectional view taken at 10--10 in FIG. 8;
FIG. 11 is a fragmentary end view of one of the parts of FIG. 9, taken from the aspect 11--11 of FIG. 9;
FIG. 12 is a view similar to FIG. 1, to show a modification of FIG. 8;
FIG. 13 is a view similar to FIG. 1, to show a two-stage coupling of the invention, embodying the basic modular structure of FIG. 1;
FIG. 14 is a longitudinal sectional view of one of the parts of FIG. 13;
FIG. 15 is a view similar to FIG. 13, to show another two-stage coupling of the invention, embodying the basic modular structure of FIG. 8;
FIG. 16 is a longitudinal sectional view of one of the parts of FIG. 15; and
FIG. 17 is another view similar to FIG. 13, to show a further two-stage coupling of the invention, embodying the basic modular structure of FIG. 12.
In FIGS. 1 to 4, the invention is shown in application to first and second coupling members 10-11 on separate axes of rotation 12-13 which intersect at a point P. The coupling members 10-11 have freedom to change the degree of aligned or misaligned relation between their axes 12-13, through universal swivel action about the point P, the center of their articulation. To this end, the coupling members 12-13 have coacting formations, in the nature of a ball-and-socket joint, to assure constancy of the articulation center point P. As shown, member 10 embodies a centering ball 14 fixedly mounted to the suitably formed end of a shaft 15, and member 11 has the socket formations, namely, a first cupped half 16 fixedly mounted to a shaft 17 and having within its closed end a central concave spherical ball seat 18 of limited extent α 1 about the point P, and a second cupped half 19 having a series of angularly spaced ball-stabilizing radially inward feet 20; feet 20 are adjacent the rim 19' of a large central opening in the reduced end of the cupped half 19, allowing a wide range universal freedom±β for articulation of axes 12-13 about point P. Another and similar series of angularly spaced ball-stabilizing inward feet 21 is provided within the cupped half 16. And the ball-contacting inner surfaces of feet 20-21 will be understood to be formed to the same concave spherical geometrical surface as that of seat 18, thereby effectively fixing the position of point P, when the cylindrical walls of the cupped halves 16-19 are secured in telescoped relation, as shown in FIG. 1.
In accordance with the invention, torque transmission from one to the other of the coupling members 10-11 is accomplished via a series of radially inward teeth carried by one coupling member and meshing with a corresponding series of radially outward teeth carried by the other coupling member, and it makes no difference which of these members is the input or driving member and which is the output or driven member. As shown, the radially outward series of teeth 22 is carried by the ball 14, and the radially inward series of teeth consists of cylindrical studs 23 to each of which a bushing 24 has been rotatably fitted, the studs 23 being angularly spaced around and fixed to the bore of a mounting ring 25, and ring 25 in turn being in fixed centrally seated relation within the fitted confines of the cupped halves 16-19 of member 11. The number n of teeth in each series is the same and may be odd or even; as shown, the number of teeth in each series is nine. And each tooth has a frusto-conical outer surface which converges to the point P; preferably, the angular spread α 2 of each frusto-conical tooth surface is substantially π/n radians, so that at alignment of the shaft axes 12-13, the then fully meshing tooth surfaces 22-24 of both series will account for substantially 2π radians, i.e., substantially the full circumferential extent.
FIG. 5 illustrates that, for a given angular misalignment β as between the axes 12-13, the teeth 24 orbit about the center P in a first plane 24' that is normal to the axis 13, while the teeth 22 orbit around the center P in a second plane 22' that is normal to the axis 12. These planes and orbits intersect on an alignment 26 which represents a diameter common to the respective orbits, and the alignment 26 is always through the point P and perpendicular to the plane common to (i.e., defined by) the intersecting misaligned axes 12-13. It is in the region of approach to and departure from the alignment 26 that teeth 22-24 have their torque-transmitting meshing relation, as becomes apparent from the fragmentary diagram of FIG. 6, wherein shading in one set of teeth (22) is used to more clearly differentiate said one set from the other set (24). The relation depicted in FIG. 6 will be understood to apply for each of the diametrically opposite points of orbit intersection, the force reactions upon toothed engagement at the respective orbit intersections being equal and opposite, as denoted by vector arrows at these intersections in FIG. 5. Stated in other words, upon approach to each of the orbit-intersection points, the teeth 24 of one set may be viewed as gradually approaching a median plane 27 from one side, while the teeth 22 of the other set make a correspondingly gradual approach to the opposite side of the same plane 27, said plane 27 including the point P and the alignment 26, and being the bisector of the instantaneous angle between orbits 22'-24'. As a practical matter, each tooth-to-tooth contact is a line contact (aligned with center P) and is operative over a range of shaft-increment angles such that torque is always being effectively transmitted in substantially equal and opposite magnitudes at both zones of orbit intersection, with total symmetry about the point P and both rotary axes 12-13. And by providing a rotary bushing 24 on each of the teeth of one set, it is assured that all torque-transmitting contacts will be rolling contacts, with attendant low-friction action throughout the shaft-angle range for which each tooth-to-tooth contact is serving its torque-transmitting function.
Although elements 24 are described as bushings, in view of their indicated function, it will be understood that, in addition to being charcterized by a frusto-conical outer surface and cylindrical bore, they may be cupped, as shown, with a closed end 28 adjacent the sphere of ball 14, said closed end being concaved to the radius of the ball sphere for ball-piloted location of each bushing 24. The material of bushings 24 will depend upon the load to be transmitted, and for all but the heaviest-duty applications, bushings 24 may be injection-molded of a suitable low-friction material such as high-density polyethylene, polypropylene or the like.
The arrangement of FIG. 7 will be recognized for its similarity to FIG. 1 and therefore many of the same reference numbers are used, for corresponding parts. The principal differences in FIG. 7 are that the mounting ring 25 for studs 23 is fixedly seated in corresponding adjacent counterbores of the respective cupped halves 16-19, which are thereafter secured as by welding, suggested at 29.
The embodiment of FIGS. 8 to 11 is illustrated by drawings which are the close counterpart of FIGS. 1 to 4, the difference being that ball-and-socket retention of the center P in FIGS. 8 to 11 is completely independent of the torque-transmitting function of teeth of the inner and outer sets 22 and 23-24. The shaft 17, which will be referred to as the input shaft (although it could just as well be the output shaft) is fixed to a coupling member 30 which is again a cupped half but which has an inner surface in the form of a concave hemisphere, to match and slidingly nest the sphere of ball 14, to which the output shaft 15 is affixed. Also affixed to shaft 15, as by key means 31, is a cupped member or shell 32, substantially hemispheric about the center P and at radial offset from member 30, to an extent permitting the respective sets of coacting teeth 22 (23-24) to be carried by radially opposed orbit-encompassing regions of the members 30-32. A retainer ring 33 with concave spherical ball-engaging inner surface is secured as by threads to a threaded counterbore in member 30, and a snap-ring 34 in a groove formation provides a locating shoulder to assure correct positioning of member 32 with respect to the articulation center P. The studs 23 of the outer teeth 24 are again precisely and fixedly mounted to a ring member which may be welded at 35 to become a permanent part of the driven coupling member 32.
FIG. 12 will be recognized for its similarity to FIG. 8, and therefore the same reference numbers identify parts which functionally correspond. The principal differences reside in use of a cupped cylindrical shaping of the outer shell 36 which carries the studs 23 for the radially inward rotatable teeth 24, and also in the manner in which shell 36 is fixedly mounted to the flanged end of its shaft 37. As shown, the closed end of shell 36 has a central aperture which centrally locates a center projection of the end of shaft 37 and which also centrally locates a corresponding central projection of a flanged stub shaft 38 which is the means of connection to ball 14. Bolts 39 clamp the flanges of shaft means 37-38 to each other and to the shell 36.
FIG. 13 illustrates that the described embodiment of FIGS. 1 to 4 is essentially modular in nature, lending itself to back-to-back series-connection in order to achieve an effective doubling of the degree of off-axis misalignment through which torque may be transmitted. This misalignment is depicted as 2β, as between the axis 40 of an input shaft 41 and the axis 42 of an output shaft 43, each of the shafts 41 (43) being keyed to its own ball 44 (45). A special intermediate ring-like member 46 provides closely adjacent concave spherical ball seats 47-47' of the nature described at 18, along with spherically finished ball-engaging feet 48-48' of the nature described at 21. First and second rings 25 carry the studs for radially inward tooth sets 24 serving the radially outward tooth sets 22 on each of the respective balls, rings 25 being spaced by the cylindrical periphery of member 46 and fixedly seated in counterbores of outer cupped half members or shells 50-51. Ball-engaging feet with concave-spherical inner surfaces, as described at 20 (FIGS. 1, 2, 3) will be understood to characterize shells 50-51 near the rims of their respective end openings 52-52'.
FIGS. 15 and 16 illustrate the modular nature of the embodiment of FIGS. 8 to 11, in a back-to-back series-connected or tandem arrangement of two modules. The truncation is made at the base of the hub 30' (FIG. 9) of the coupling member 30, to produce first and second such members 60-61 which are shown welded back-to-back at 62. Each half of the tandem-connected double joint of FIG. 15 is otherwise as described for the coupling of FIGS. 8 to 11 and therefore the same reference numbers are employed to identify cooperating elements for smooth torque transmission between shafts 63-64, over the widely divergent axis-misalignment range 2β. Thus, a first ball 14 and coupling shell 32 (with radially inward teeth 24) are fixedly mounted to the end of shaft 63, and a corresponding ball 14' and coupling shell 32' (with radially inward teeth 24) are fixedly mounted to the end of shaft 64. And the twin coupling members 60, each with its set of radially outward teeth 22, are held by their respective retaining rings 33-33' to the balls 14-14'.
The embodiment of FIG. 17 will be recognized as a tandem employment of the basic modular structure of FIG. 12, for coupling shafts 66-67 with a 2β range of angular flexibility. The shaft 66 is fixed to the upper coupling or socket member 68 which with its retaining ring 33 locates the upper ball 69, and shaft 67 is similarly fixed to the lower coupling or socket member 68' to locate on the lower ball 69'. The balls 69-69' are interconnected by a pin connection 70 through telescopically lapped regions of their respective stub shafts 71-71'. The members 68-68' are each equipped with a set of radially outward teeth 22, and the respective open ends of a cylindrical shell member 72 mount the studs 23 for radially inward teeth 23 in each of two sets (at levels denoted A-B) to mesh with the respective tooth sets 22 of balls 69-69'. A mounting bulkhead 73, forming part of shell 72 has a cylindrical hub in which the telescoped ends of stub shafts 71-71' are received and held (by pin 70). Preferably, pin 70 has a sufficiently threaded shank, as shown, to enable manipulating access and thread-locking via a locally tapped region of shell 72.
The various described embodiments will be seen to have achieved all stated objects of the invention. Polar-coordination is an expression which may be applied to explain why my coupling lends itself so favorably to torque transmission, with such a wide range of angular misalignment β. By polar-coordination is meant that all actions and all cooperating surfaces have the same coordinated referencing to the center P. This is the center of ball-and-socket swivel universality. It is also the center of orbiting for both sets of the teeth which mesh, and it is the center to which all tooth axes and all frusto-conical tooth surfaces (and all line contacts between meshing teeth) converge. Power transmission by-passes the ball-and-socket engagement, because torque is not concentrated at one point but rather at two diametrically opposite locations, whereby ball-reaction force is substantially eliminated. Friction and wear between teeth is minimized by the roller-like (rotatable) suspension of the teeth of at least one set, here described as the radially inwardly directed set 23-24. As indicated, use of low-friction material at 24 may provide the sole lubrication needed for many applications; for heavier-duty applications, each ball (14) need not be solid but could contain a reservoir for lubricant, to be dispensed gradually under centrifugal force.
With an even number n of teeth in each of the sets 22-24, there are diametrically paired contacts, for every tooth distance or pitch. With an odd number n of teeth in each of the sets 22-24, there is a succession of single contacts every half pitch, although the range of shaft-angle advance for operability of such single contacts is found to be sufficient for the contacts to be effectively diametrically paired, even though the number n may be odd, as in the nine-tooth per set example herein described. Both the n-odd and n-even cases have their specific fields of use, n-odd providing the smoothest operation for large values of β, and n-even providing the greatest torque transmitting capability that is entirely free of ball-and-socket reaction.
The parts are basically simple, and the cylindrical-shell configurations of FIGS. 12 and 17 are to be preferred for largest values of β, being shown in these figures to provide for β=45°, as determined by freedom of the stub shaft 38 (71-71') within the opening of the ball-retaining ring 33.
While the invention has been described in detail for preferred forms shown, it will be understood that modifications may be made without departing from the scope of the claimed invention. | The invention contemplates a universal coupling wherein rotatable input and output members are coupled both (1) for universal flexible accommodation of the instantaneous angular orientation (misalignment) of their rotary axes about a single point of axis intersection and (2) for gear-tooth drive engagement in the transmission of torque from one to the other of these members. The result is to achieve both (1) and (2) above (a) for a greater range of axis misalignment than is possible with universal couplings of the past, (b) with greater uniformly high torque transmission as a function of incremental rotation of the coupling members, and (c) with symmetry of torque-transmitting force development with respect to the axes of rotation. | 5 |
This invention relates to security braces for doors to prevent unauthorized opening of the door, and has particular reference to a power operated door brace and a remotely controlled door brace.
BACKGROUND OF THE INVENTION
Many types of security devices for door have been devised to prevent unauthorized entry of rooms especially in hotels and motels. Throw bolts are commonly used and those operated only from the inside of the room are preferred. Many persons distrust the strength of throw bolts and braces from the floor to doorknobs have been devised. These braces extend at an angle from the floor to the doorknob and are sometimes extendable in length to get a firm grip on the floor as the upper end presses against the doorknob. These devices are generally operable only from the inside of the room and cannot be put in place on the inside of the door when the occupant leaves the room. The room, is then available for unauthorized entry by anyone with a key to the lock.
BRIEF SUMMARY OF INVENTION
I have devised a power operated doorknob security brace, that is operable not only from inside the room but from the outside as well. I provide a brace that is extendable or retractable by power. Further I provide a remote control for the power operated brace so that it can be extended after the occupant leaves the room to lock the door and can be retracted from outside the room to permit opening of the door. I prefer a radio remote control and the circuits used for remote arming and disarming have proved to be satisfactory.
BRIEF DESCRIPTION OF THE DRAWINGS
In the drawings forming an integral part of this specification:
FIG. 1 is a diagram of a presently preferred embodiment of my invention showing a brace secured to the doorknob and retracting to lift the brace foot from the floor.
FIG. 2 is a diagram of the devise of FIG. 1 with the brace extended so that the foot engages the floor so that the upper end presses against the doorknob, and showing remote control radio transmitters.
FIG. 3 is an elevation view, partly in section showing the brace of FIG. 1 separated into two parts for convenient storage or transportation.
FIG. 4 is a sectional view along the line IV--IV of FIG. 3 showing one of the two snap brackets for holding the bottom portion of brace to the upper portion.
FIG. 5 is a diagram on a smaller scale of the two brace portions together by the snap brackets of FIG. 4.
FIG. 6 is a top view or plan view of the foot of FIG. 3 and a portion of the brace.
FIG. 7 is an elevation view of a flexible foot shoe with projecting to engage carpet in a room.
FIG. 8 is an elevation view of an attachment that is slipped under a door when it is open and upon door closing is hooked to the that the foot cannot be dislodged by persons push rod under the door when the door is closed.
FIG. 9 is a schematic circuit for the device.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to FIG. 1 there is illustrated a brace 10 embodying my invention having an outer tube 11 within which reciprocates an inner tube 12. The brace 10 is secured at its upper end to a doorknob 13 on a door 14 which swings to the left to open. The door 14 is the entrance to a room (not shown) which has a floor 16.
Disposed on the bottom end of the brace 10 is a pivoted foot 17. Projecting horizontally from the brace is a pivot arm 18 normally held in a horizontal position. This arm 18 rests against the door 14 to hold the brace 10 at an angle to the door, which angle may be 30 degrees or greater for best results. The brace 10 is shown in its retracted position in FIG. 1 which permits the door 14 to be freely opened or closed.
Illustrated in FIG. 2 is the brace 10 in its extended condition wherein the foot 17 engages the floor 16 and prevents 14 from swinging to the left. The extension is accomplished by an internal motor 19 supplied with electrical current from any suitable source, such as internal batteries. The motor 19 is controlled by a radio receiver and associated electronics 21 which may be an off-the shelf arming and disarming circuits. Coded radio waves are sent directly to the radio receiver 21 by a hand held transmitter 22 and radio waves are transmitted through the door 14 by a hand held transmitter 23. The transmitters are preferably also off-the-shelf remote arming and disarming transmitters. When the code supplied by the transmitters is identical to the code recognized by the receiver 21, then the brace 10 will extend or retract depending upon the state of a flip-flop in the electronics 21. The flip-flop in the circuit permits the use of the same radio signal to extend or retract the brace 10, although separate extend and retract signals could be used.
While any suitable transmitting medium can be used, such as ultra sonic sound waves, I prefer radio waves because the transmitters and receivers are readily and inexpensively available.
Referring to FIG. 3, there it will be noted that the exterior tube 13 and its inner telescoping tube 12 may be separated from an upper tubular member 15. This connector for separation (and connection) of the tube 13 to the tube 15 may be of any suitable type and there is shown a bayonet connection wherein pins 24 fit in curved slots 26. A simple twisting action connects or disconnects the upper part 15 from the lower part 13. The upper end of part 13 abuts a thrust ring 30 which insulates the motor 19 and gear box 33 against compressive forces.
Referring still to FIG. 3, the upper tube 15 has on its upper end a yoke 27 to which is attached a strip of fabric 28 that passes over the shaft 25 of the inner doorknob 13 to hold the upper end of brace 10 to the door 14. This fabric strip 28 may have hooks or loops on one surface that engages loops or hooks on a piece (not shown) on the far side of the yoke 27. Such fabrics are sold under the trademark of Velcro and other names.
The yoke 27 is part of a cap on the tube 15 in which are disposed a plurality of batteries 29 which are preferably rechargeable and recharging can be done in place by an optional recharging unit 30 which can be plugged into any conventional outlet. The recharging unit 30 may include a step down transformer connected by a cord 31 to a plug 61 fitting into a socket 62 on upper tube 15. This recharging is especially useful when the brace 10 is left in place for a matter of weeks or months and the smaller constant drain might otherwise deplete the batteries and cause the door to remain permanently locked.
Referring still to FIG. 3, the motor 19 is connected to a gear reduction unit 32 preferably an off-the-shelf planetary gear unit which has a recess 33 to receive a splined shaft 34 projecting from the lower tube 13. The splined shaft is rotated by the reduction gears 32 and it is connected to a threaded shaft 36 which threads into a non-rotatable nut 37 secured to the upper end of the inner tube 12. The inner tube 12 (and the nut 37) are prevented from rotating by a pin 38 projecting from the inner tube 12 into a longitudinal slot 39 in the outer tube 13.
Illustrated in FIG. 5 is a break down of the brace 10 wherein the lower tubes 13 and 12 and the foot 17 are held to the tube 15 by a pair of snap brackets 41 shown in detail in FIG. 4.
Referring now to FIG. 8 there is illustrated an attachment 42 having a channel 43 that slips under the door 14 when it is open and which has an extension 44 terminating in a ratchet adjustment 46. To the left of the adjustment 46 is a shank 47 terminating in a hook 48 that engages a complimentary hook 49 in the foot 17. The two hooks are engaged when the attachment 42 is generally vertical and thereafter the attachment is rotated to a horizontal position and slipped under the bottom of the door 14 when it is open. The door is then closed and the adjustment 46 is tightened against the restraint of the horizontal arm 18. The purpose of attachment 42 is to prevent persons in high risk areas from inserting rods under the door to push the foot 17 inwardly to release the brace 10. A soft rubber bumper 51 can be moved against the inside of the door 14 to hold the channel 43 in the position shown so that it will not drag as the door 14 swings on its hinges.
The device can be used in rooms with hard wood, concrete or other floors devoid of carpeting. For this purpose the foot 17 has a layer of soft rubber or plastic 52 to grip the floor regardless of minor unevenness. For carpeted floors a tooth shoe 53 is snapped over the foot 17 and this is shown in FIG. 7 wherein teeth 54 point to the left and the shoe is held by an integral hook 56 engaging a projection 57 on the foot.
OPERATION
The device will normally be transported in a suitcase or other containers in the form shown in FIG. 5. The parts are then disengaged and aligned as shown in FIG. 3. The lower tube 13 is inserted within the lower end of the tube 15 so that the splined shaft fits in the gear box recess 33. A relative rotation of tubes 13 and 15 engages the slots 26 and pins 24 to fasten the two together. The Velcro strap 28 is next passed over the shaft 25 of doorknob 13 to hold the brace 10 to the door 14. The arm 18 is rotated to the position shown in FIG. 3 to hold the brace 10 at an angle with respect to the door 14.
The operator next presses an on-off switch 55 at the upper end of the radio receiver 21 (FIG. 3). The device is now ready for radio control.
Shown in FIG. 1 is the device in retracted condition. If the occupant of the room desires to brace the door against intruders, he operates the radio transmitter 22 of FIG. 2 resulting in an "extend" signal which is transmitted through the air to the receiver 21. The electric motor 19 then uses current from batteries 29 (FIG. 3) to rotate the threaded shaft 36 within non-rotatable nut 37 to extend the brace 10 to the condition shown in FIG. 2. An automatic limit stop (shown in FIG. 9) stops the motor when a sensor detects an overload condition of current at the limit of extension when the foot 17 engages the floor, or retraction when the pin 38 reaches the upper end of slot 39.
If now the occupant desires to leave the room he operates radio transmitter 22 resulting in a "retract" signal whereupon the receiver 21 causes the foot 17 to be lifted as shown in FIG. 1. He next opens the door 14 by swinging it to the left and proceeds through the doorway and closes the door with the brace hanging on it as shown in FIG. 1. He next operates a radio transmitter 23 (which may be the same transmitter 22) resulting in an "extend" signal whereupon the foot 17 again engages the floor 16 to lock the door. When he returns and desires to open the door he merely operates transmitter 23 resulting in a "retract" signal to the receiver 21 whereupon the foot 17 is retracted to the position shown in FIG. 1. The person then enters his room.
Referring to FIG. 8 the extension 44 and shank 47 can be described as telescoping members and the ratchet adjustment 46 constitutes means for locking these telescoping members at any desired over all length.
Referring to FIG. 9 there is illustrated a schematic diagram of a circuit for carrying out the radio commands. In the upper right the motor 19 is shown as well as motor battery 29. The battery 29 is connected to the motor 19 through a pair of relays 61 and 62 that determine the direction of rotation of the motor 19. The relays are sown in their non-energized positions. As shown in FIG. 9 the motor is in the OFF mode because the two relays are connected to a common side of the battery 29. The battery is connected to the motor through a series resistor R. If now a radio signal is received and recognize by the circuit, one of relays 61 and 62 will be energized and the relay armature of the energized relay will swing to the left completing a circuit from the battery 29, through the resistors R and through the motor 19.
If now the motor has fully extended or retracted the member 12 (FIG. 3), the movement will be mechanically stopped and as the motor 19 tries to overcome the stop, the current from battery 29 will drastically increase. This creates a voltage change across the series resistor R which is amplified by amplifier A and this amplified signal is fed to a comparator C which compares the voltage to an internal standard. When the standard is exceeded the comparator sends a signal to a flip-flop 63 which is the on-off flip-flop. When the signal from the comparator C is high, flip-flop 63 is reset turning off (opening) FET switch 64 which opens the circuit to the relay coils, allowing the relays to assume the position shown, and stopping motor 19. Switch 64 is normally open and is closed only during the 7 to 21 second period required to extend or retract member 12.
If now a radio signal is turned on (FIG. 2) from transmitters 22 or 23, its code can be recognized by a receiver 66 which sends a signal to a timer 67 which is turned on for a selected time period and it will refuse any new signal during that time period. I presently prefer a time period of 25 seconds because the inner tube 12 can be fully extended or retracted in 21 seconds. The signal from receiver 66 is transmitted through the timer 67 to a flip-flop circuit 68 connected to two switches FET 69 and FET 71 connected respectively to the relays 61 and 62. One of switched 69 or 71 is normally closed. The flip-flop circuit 68 will open the switch 69 or 71 which was previously closed and close the switch 69 or 71 which was previously open.
Therefore if the prior operation of the device was to extend the inner tube 12, then flip-flop 68 will cause the next operation to retract tube 12, and vice versa. This is done when one of switches 69 or 71 closes the circuit to the respective relay 61 or 62. This causes the affected relay to switch to the other terminal from that shown in FIG. 9, thus completing a circuit from the battery 29 to the motor 19. Simultaneously with the operation of flip-flop 68, the signal from the receiver 66 is transmitted through the timer and by a branch wire 72 to the on-off flip-flop 63. This is a high input and causes switch 64 to close. This closes a current to both relays 61 and 62 and energizes one or the other of relays 61 and 62, causing the motor to rotate in one direction or the other to extend or retract telescoping member 12. This direction of rotation is controlled by switches 69 or 71 as previously explained.
Referring to the lower left part of FIG. 9, connected to comparator C is a timer 73 which operates an audio sounder 74 for a few seconds to signal the completion of the extension or retraction movement.
I have described my invention with respect to my presently preferred embodiment as required by the patent statutes. It will be obvious to those skilled in the art that various modifications and variation can be made. I include all variations and modifications that come within the true spirit and scope of my invention within the scope of the following claims. | An inclined security brace for a door extends from the door knob to the floor and has telescoping parts that are extended and retracted by an electric motor. A horizontal arm keeps the brace in an inclined position when the brace is retracted. The motor is activated by radio controls having a circuit that controls the direction of retraction or extension. When the extension operation causes the brace to engage the floor an over load of the electronic motor occur and this over load is sensed by the circuit to stop the motor. When the retraction operation results in the telescoping parts reaching a mechanical stop the over load is again sensed by the circuit to stop the motor. Preferably the same transmitted signal is used for retraction and extension and a flip-flop in the circuit automatically alternates extension and retraction. The brace prevents entry to a room by pass keys. | 4 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to containers for storing and/or transporting materials. More particularly, the present invention relates to semi-rigid collapsible containers that may be employed to transport bulk materials including, but not limited to, hazardous materials.
2. Discussion of Background Information
Metal containers are generally used to store and transport bulk materials, particularly hazardous materials. These metal containers are expensive to purchase, rent and store. They are fairly large and therefore require a considerable amount of space to maintain on site. That required space could be considerable, dependent upon the amount of material that must be stored and/or transported. While the storage volume of metal containers is considerable, the volume of material that is storable within multiple containers is diminished by the fact that the metal containers are generally cylindrical in nature. Cylinders generally cannot be oriented in a space-efficient manner. As such, there is a need in the art for containers that will contain a high volume of material and be storable in a low volume storage facility.
To meet this need, bag containers have been employed. Such bags take up much less space when not in use. However, such bags are of insufficient physical characteristics for transport purposes. That is, they are generally not tough enough to stand up to the rigors of movement by mechanical devices such as forklifts, accidental drops into cargo holds, stacking, and the like. Moreover, bag containers are easily deformed by the materials that they contain. As such, bag containers are not reliably stackable, and hence bag containers do not provide for efficient transport or storing of voluminous materials.
In order to overcome the limitations associated with flexible bags and rigid metal boxes, a series of semi-rigid containers have been developed. While these containers provide storage and transport benefits, they lack the rigidity and impermeability to contain a wide range of materials, such as hazardous materials. Therefore, what is needed is a rigid container for the storage and transport of bulk materials suitable for retaining a range of materials. What is also needed is a collapsible container that minimizes the exposure of the materials to the surrounding environment. Lastly, there is a need in the art for a collapsible container that can reliably hold its shape while stacked during storage and transport.
SUMMARY OF THE INVENTION
Accordingly, the present invention includes a collapsible container having an internal truss system for use in a variety of applications. The container of the present invention includes a continuous rigid structure that defines a plurality of sides. In an effort to minimize the space occupied by the container during storage, the continuous rigid structure is collapsible via a pair of scoring lines disposed on opposing surfaces. The continuous rigid structure is buttressed by an internal truss system that includes at least one inelastic member. The inelastic member is preferably composed of a synthetic material of a fixed length and dimension. The inelastic material is then threaded through the sides of the continuous rigid structure such that it provides a symmetric and rigid supporting structure for the scored surfaces of the continuous rigid structure.
As further described herein, the continuous rigid structure is preferably four-sided, such that it defines four continuous surfaces of a cube. In one embodiment, a liner is integrally affixed to each of the four sides and additionally provides a fifth side that forms the bottom of the container. A protective cover is secured to the exterior of the continuous rigid structure for protecting the contained materials against the elements.
The container of the present invention is selectively sealable via a pair of flaps that form part of the cover. The flaps are selectively attached to the exterior of the cover through a mechanical means, such as a loop and eyelet closure. In such a manner, the container can be easily and effectively sealed for stacking and transport without worry that the materials contained therein will be unnecessarily exposed to moisture and debris. The container of the present invention is also collapsible for storage and empty transport, as noted above.
The container of the present invention thus provides numerous benefits over the existing art. Namely, the internal truss system of the container of the present invention combines the benefits of a metal container with the adaptability of a semi-rigid container. Moreover, the liner and cover cooperate to render the container of the present invention substantially impervious to environmental damage that otherwise might harm the materials within.
The present invention is directed to a collapsible container includes a continuous rigid structure defining four sides, two of the four sides having a first scoring line and a second scoring line rendering the continuous rigid structure collapsible. Each of the four sides defining a first pair of passages and an inelastic member connecting the four sides such that the inelastic member passes through each of the first pair of passages within each of the four sides thus providing support for the continuous rigid structure.
The present invention is directed to a method of making a collapsible container that includes providing a four-sided continuous rigid structure wherein a first scoring line and a second scoring line are defined on opposing sides. The method includes providing an inelastic member having a first end and a second end. Collapsing the four-sided continuous rigid structure such that it is a substantially planar collapsed continuous rigid structure. Punching at least two passages through the collapsed continuous rigid structure, and threading an inelastic member through the at least two passages of the collapsed continuous rigid structure. Fastening the first end of the inelastic member to the second end of the inelastic member.
Further features and advantages of the present invention are described in detail below with reference to the following drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an elevated perspective view of the collapsible container of the present invention.
FIG. 2 is a plan view of the collapsible container of the present invention shown in FIG. 1 .
FIG. 3 is a plan view of the collapsible container of the present invention in an early step in a method of making the same.
FIG. 4 is a plan view of the collapsible container of the present invention in an intermediate step in a method of making the same.
FIG. 5 is a plan view of the collapsible container of the present invention in a later step in a method of making the same.
FIG. 6 is an elevated partial cut-away perspective view of a collapsible container in accordance with an alternate embodiment of the present invention.
FIG. 7 is an exploded perspective view of a collapsible container in accordance with an alternate embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The present invention provides an internal truss system for a semi-rigid container that is sturdy enough for stacking, storing and transporting a variety of materials. In its preferred embodiments, the semi-rigid container of the present invention is collapsible. Therefore, unlike the ubiquitous metal containers, the container of the present invention can be collapsed from a substantially cubic volume into a substantially flat square for easy stacking and storage. The present invention thus provides numerous benefits to the user, as described more fully below with reference to the figures.
FIG. 1 is an elevated perspective view of the collapsible container 10 of the present invention. The container 10 preferably includes a first side 12 , a second side 14 , a third side 16 and a fourth side 18 , all of which cooperate to define a substantially cubic volume therein. The plurality of sides 12 , 14 , 16 , 18 preferably delineate a continuous rigid structure 20 that is formed from a semi-rigid material such as plastic, fiberboard or cardboard. In a preferred embodiment, the continuous rigid structure 20 is formed of cardboard such that it can be easily and economically produced while providing a substantial amount of rigidity as a containment device.
The continuous rigid structure 20 includes a pair of scoring lines 22 that are preferably disposed on opposing sides. For example, the scoring lines 22 may be disposed on the first side 12 and third side 16 , or alternatively on the second side 14 and the fourth side 18 . The scoring lines 22 are preferably disposed along the center of the respective sides thereby ensuring uniform and symmetrical folding attributes as described more fully below. That is, a scoring line disposed on the first side 12 will be disposed equidistant between the junction of the first side 12 and the second side 14 and the junction between the first side 12 and the fourth side 18 , as illustrated in FIG. 1 .
As the continuous rigid structure 20 is preferably comprised of a semi-rigid material as noted above, the collapsible container 10 of the present invention includes at least one inelastic member 30 that interconnects each respective side of the continuous rigid structure 20 . As shown in FIG. 1 , there are two inelastic members 30 that are interwoven between the four sides of the continuous rigid structure 20 in a symmetrical fashion so as to define a network of internal trusses between each of the four sides. In a preferred embodiment, each of the inelastic members 30 shown is formed from a single element that is connected to itself at an overlap 32 . The inelastic members 30 are shown anchored to each of the four sides of the continuous rigid structure 20 by passing through a series of passages 34 that connect an inner surface of each of the four sides to an opposing outer surface. In such a manner, the internal truss system defined by the inelastic members 30 is integrated into the continuous rigid structure 20 thus forming the collapsible container 10 .
FIG. 2 is a plan view of the collapsible container of the present invention shown in FIG. 1 . As shown, the inelastic member 30 forms a substantially octagonal profile by alternating periods on the inside of the continuous rigid structure 20 with periods on the outer surfaces of the respective sides. The inelastic member 30 is shown disposed on the outer surface of the fourth side 18 . Following the arrows in FIG. 2 , the inelastic member 30 is then pressed through a pair of passages 34 on the fourth side 18 , through which the inelastic member 30 is shown angling towards both the first side 12 and the third side 16 . At the first side 12 and the third side 16 , the inelastic member is pressed through a pair of passages 34 , from which it angles towards the second side 14 . Through another pair of passages 34 on the second side 14 , the inelastic member 30 meets and is fastened to itself at the overlap 32 .
In a preferred embodiment, the inelastic member 30 is of a length suitable for providing a tension between the four sides of the continuous rigid structure 20 such that the continuous rigid structure 20 maintains a substantially square shaped profile as shown in FIG. 2 . Of particular concern is that the scoring lines 22 disposed on opposing sides of the continuous rigid structure 20 must be able to withstand a substantial load as the collapsible container 10 of the present invention is filled. As such, the inelastic member 30 is preferably composed of a material that is light, inelastic and easy to deform into the necessary profile for creating the internal truss system for the collapsible container 10 . In preferred embodiments, the inelastic member 30 is polypropylene or polyester, although any other suitable synthetic, organic or inorganic polymer that can maintain its inelasticity under a load is suitable for use in the present invention.
FIG. 3 is a plan view of the collapsible container 10 of the present invention in an early step in a method of making the same. As shown, the collapsible container 10 is in a collapsed state in which it forms a substantially planar cross-section. By folding in along the scoring lines 22 , a user can compress the continuous rigid structure 20 in an accordion-like manner for easy storage and transport when not in use.
In order to form the internal truss system described above, the planar continuous rigid structure 20 is perforated to form the plurality of passages 34 , which pass continuously and symmetrically through each of the four sides of the continuous rigid structure 20 . In a preferred embodiment, the plurality of passages 34 are formed by a pressing machine adapted to thread the inelastic member 20 through the passages 34 as it creates them. Alternatively, the process of forming the plurality of passages 34 and the placement of the inelastic member 30 therein may be performed manually. As discussed further below, it is also conceived that the continuous rigid structure 20 of the present invention will be lined on its interior surfaces, in which case it is desirable to fit the liner into the continuous rigid structure 20 prior to threading the inelastic members 30 through the plurality of passages.
FIG. 4 is a plan view of the collapsible container of the present invention in an intermediate step in a method of making the same. In FIG. 4 , the inelastic member 30 is shown fastened to itself at the overlap 32 . The means for fastening the inelastic member 30 to itself may include mechanical devices, adhesives and other bonding techniques. For example, the inelastic member 30 may be fasted to itself using staples, epoxies or resins. Preferably, however, the means for fastening will be an automated process such as sonic welding, which is particularly well suited to bonding materials composed of synthetic polymers such as polypropylene and polyester. As shown in FIG. 4 , the overlap 32 of the inelastic member 30 is located near the outer surface of the second side 14 . While it is understood that the overlap 32 can be located at any point along the continuum of the inelastic member 30 , it is preferred that it be located near the outer surface of a side of the continuous rigid structure 20 that does not have a scoring line 22 .
FIG. 5 is a plan view of the collapsible container of the present invention in a later step in a method of making the same. As noted before, the inelastic member 30 is preferably of a single length of material that, when stretched to its limit, will maintain the substantially square profile of the continuous rigid structure 20 . In particular, when a load is placed upon the inner surfaces of the continuous rigid structure 20 , the sides of the continuous rigid structure 20 that have the scoring lines 22 therein will not bow or deform in an outward direction. However, as previously noted, the inelastic member 30 will permit the inward folding of the continuous rigid structure along the scoring lines 22 , thus allowing a user to collapse the continuous rigid structure 20 into a substantially planar form as shown in FIG. 3 .
FIG. 6 is an elevated partial cut-away perspective view of a collapsible container in accordance with an alternate embodiment of the present invention. As noted above, the present invention may incorporate a liner 40 that is uniformly affixed to the interior surfaces of the continuous rigid structure 20 . In a preferred embodiment, the liner 40 is sufficiently large to include a top portion 42 that can be folded over and affixed to the outer surfaces of the continuous rigid structure 20 , as shown in magnified portion M 2 . As previously noted, the liner 40 will incorporate the passages 34 through which the inelastic structure 30 passes, as it is preferred to affix the liner to the continuous rigid structure 20 prior to assembling the internal truss of the present invention.
The liner 40 preferably includes a fifth surface that forms the bottom portion of the container 10 . The liner 40 is preferably form-fitted to the four sides 12 , 14 , 16 , 18 of the continuous rigid structure 20 and uniformly affixed thereto by glue, epoxy, resin or any other adhesive that is known in the art. The liner 40 is affixed to the four sides 12 , 14 , 16 , 18 in such a manner so as to render it coplanar with each of the four sides 12 , 14 , 16 , 18 . That is, the liner 40 is affixed to substantially all of the interior surfaces of the respective four sides 12 , 14 , 16 , 18 , as shown in magnified portion M 1 . As the liner 40 also includes the bottom portion, the liner 40 and four sides 12 , 14 , 16 , 18 define five sides of a substantially symmetric cubic structure. The liner 30 is preferably composed of a water resistant or water proof synthetic material that is also resistive to degradation by temperature and corrosive compounds.
The continuous rigid structure 20 , inelastic member 30 and liner 40 can be utilized as an integrated unit as shown further in FIG. 7 , which is an exploded perspective view of a covered collapsible container 100 in accordance with an alternate embodiment of the present invention. As shown, the continuous rigid structure 20 , inelastic member 30 and liner 40 form a lined semi-rigid container 50 that may be utilized on its own for the storage and transport of various types of materials. In another embodiment, the lined semi-rigid container 50 may be disposed within a cover 60 that fully encloses and encapsulates both the lined semi-rigid container 50 and its contents.
The cover 60 defines a substantially cubic form that is disposed over the lined semi-rigid container 50 . The cover 60 further defines a bottom (not visible), as well as two flaps 64 , 66 that, in use, cooperate to enclose the contents of the container 100 . The cover 60 also includes a plurality of tabs 62 that may be fixed to the interior of the four sides 12 , 14 , 16 , 18 of the lined semi-rigid container 50 for securing the cover 60 thereto. The plurality of tabs 62 may be so affixed by glue, epoxy, resin or any other adhesive that is known in the art.
The flaps 64 , 66 include at least one end portion 68 for selectively engaging the cover 60 of the container 100 , thereby securing its contents. Any conventional and secure fastening means may be used to secure an end portion 68 of a flap 64 , 66 to a corresponding portion of the cover 60 . For example, the end portions 68 may include a plurality of eyelets 70 that are adapted for receiving a plurality of ties 72 disposed on the exterior of the cover 60 . The user may encapsulate the container 100 by folding flaps 64 , 66 down over the cavity of the container 100 and affixing the end portions 68 to the plurality of ties 72 through the eyelets 70 . As the cover 60 is preferably composed of a water resistant or waterproof material, the user can substantially insulate the container 100 against all kinds of moisture and corrosive elements by closing the flaps 64 , 66 in the manner described above. It should be understood that the eyelet-tie mechanism is only one means by which the container 100 may be closed, and other similar mechanisms for selectively affixing two objects are regarded as equivalent to those described herein.
The container 10 , 100 of the present invention as described herein provides a number of tangible benefits over the existing rigid and semi-rigid containers known in the art. The container of the present invention is rigid enough for stacking, storing and transporting a variety of materials that other semi-rigid containers cannot handle. Through the incorporation of the inelastic members, an internal truss structure is described that provides the strength and rigidity of the less-desirable metal containers. Moreover, unlike the rigid metal containers, the container 10 , 100 of the present invention can be collapsed from a substantially cubic volume into a substantially flat square for easy stacking and storage.
It should be apparent to those skilled in the art that the above-described embodiments are merely illustrative of but a few of the many possible specific embodiments of the present invention. Numerous and various other arrangements can be readily devised by those skilled in the art without departing from the spirit and scope of the invention as defined in the following claims. | A collapsible container defined by a continuous rigid structure and an integrated internal truss system. The continuous rigid structure is preferably four-sided such that it defines four continuous surfaces of a cube. The continuous rigid structure is collapsible due to at least one scoring line defined on at least one surface thereof. The internal truss system includes at least one inelastic member that is threaded through the surfaces of the continuous rigid structure to form a symmetrical and unitary support. A liner may be integrally affixed to each of the four sides and additionally provides a fifth side that forms the bottom of the container. A protective cover may be secured to the exterior of the continuous rigid structure for protecting the contained materials against the elements. The cover can be selectively sealed for rendering the container of the present invention substantially impervious to the elements. | 1 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is an improvement of an invention disclosed in British Pat. No. 1,417,809 by the inventors of the present application and assigned to the same assignee as that of the instant application. It is also a continuation-in-part application Ser. No. 417,509, filed Nov. 20, 1973 now U.S. Pat. No. 3,953,247.
BACKGROUND OF THE INVENTION
The invention relates to an apparatus for heat treatment of material to be worked on, such as cast strips and billets, as well as ingots, rods, tubes and the like, especially of aluminum or magnesium alloys. The heat treatment is of the general type in which the material is first pre-heated and thereafter is held at a desired heat treatment temperature.
Cast strips, billets and extrusion and rolling products, are customarily subjected to a heat treatment in order to homogenize, heterogenize, or otherwise heat treat the material. For example, continuously cast billets of aluminum alloys are first pre-heated after the casting, then finally annealed at temperatures between 500° and 620° C, and thereafter cooled. During this treatment, the billets receive the structure desired for further working, such as for example extrusion or rolling. An example of such methods is found in U.S. Pat. No. 2,802,657 (Nesbitt).
The material is customarily pre-heated with circulated hot gas, flue gas or with circulated hot air. As a result of the comparatively low temperature of such a source of heat or "heater," the pre-heating step takes a very long time.
If the material is to be passed through the apparatus in a continuous manner or in a flow operation, one normally tries to transport the material at an equal and constant speed through the pre-heating zone and subsequently through the holding heat treatment zone in the furnace. If the pre-heating is of long duration, then the pre-heating zone must be disproportionately long with respect to the holding zone or the material, and upon entry into the holding zone, does not attain the proper annealing temperature.
In using prior art apparatus, in order to achieve different annealing temperatures, the temperature of the hot gas in the pre-heating area or zone and in the holding phase area or zone must be finely controllable. This is normally very difficult and a change in the temperature of the hot gas is usually only possible within narrow limits. Additionally, as was noted above, in a flow-through operation, the material must normally be transported with equal speed through the pre-heating zone and the holding zone.
As a result of the above, there is imposed upon normal operations, a restricted flexibility in treatment of materials, especially a restricted adaptability to the changing of conditions under which the material is treated.
An additional serious drawback in known devices is that during heat treatment, which eventually also comprises subsequent cooling, the material suffers uneven deformations which may result in distortion or bending of the material.
SUMMARY OF THE INVENTION
One of the principal objects of the invention is to provide an apparatus of the kind referred to above but in which the noted drawbacks are avoided and with which apparatus a material of consistent quality can be produced.
Another object of the invention is to permit improved adaptability to a variable cycle sequence sometimes required by different desired structures, different previous and subsequent auxiliary apparatus in the case of further treatment, interrupted operation or operation under part load, and the like.
Further objects and advantages of the invention will be set forth in part in the following specification and in part will be obvious therefrom without being specifically referred to, the same being realized and attained as pointed out in the claims hereof.
Other objects of the invention will in part be obvious and will in part appear hereinafter.
With the above and other objects of the invention in view, the invention consists in the novel construction, arrangement and combination of the various devices, elements and parts, as set forth in the claims hereof, certain embodiments of the same being illustrated in the accompanying drawings and described in the specification.
In general, the objects of the instant invention are attained by providing at least one pre-heating furnace which utilizes direct flame impingement to rapidly heat the material, and whose flames has a temperature essentially higher than the treatment temperature. There is also provided a holding furnace or zone, maintained at the treatment temperature, wherein the material is transported from the pre-heating furnace by means of a transport device associated with the pre-heating furnace and the holding furnace but drivable independently of the transport devices which may be provided in either furnace. This permits the material to be moved through each furnace and between the furnaces at rates that are independent of each other.
With the apparatus according to the instant invention, a number of advantages can be achieved during the heat treatment:
As a result of the passage of material through each furnace in a continuous manner, rather than in a batch-like manner, each piece or all parts of a long piece of material being treated, is treated under essentially the the same condition. Each piece is pre-heated under essentially the same conditions, without regard to variations within the furnace, both during the pre-heating and the heat treatment stages. When the material is pre-heated by means of direct flame impingement (as is disclosed in U.S. Pat. No. 3,632,093 (Elhaus) the pre-heating time is generally shorter than the heat retaining or heat treatment time. By shortening the pretreatment or pre-heating time, it is possible to better match the time for movement through the pretreatment furnace and the heat treatment furnace. For example, the time for pre-heating a billet of aluminum alloy to a peak temperature of 500° to 570° C is, depending on the billet diameter, between approximately 10 to 30 minutes. By pre-heating the billets in a separate device, an exact temperature check during the pre-heating procedure is possible. The temperature check as well as the individual adjustability of the cycle sequence or speed of the material in the preheating furnace and of the travel speed through the holding furnace, make possible adaptability to change the cycle sequence, with great flexibility, as may be desirable in view of subsequent apparatus, different alloys to be treated, interrupted operation and operation under part load.
Although the rapid pre-heating step would appear to be disadvantageous because of the large power requirement, it has, surprisingly, in practice resulted in a more economical treatment of the materials, then previously attained using prior art apparatus. This results because the reduction in time necessary to treat the materials permits a higher production capacity to capital expenditure than in known apparatus. The apparatus, according to the instant invention, permits an economical treatment in a continuous flow manner, for the material. This leads to a significant economic improvement over prior art apparatus.
An additional significant contribution to increase the flexibility, lies in the fact that the temperature-time progression during pre-heating in the pretreatment furnace, is adjustable. The billets or pieces of material can be conveyed step-by-step and each individually pretreated in stationary condition in the pe-heating furnace, if that is desired. Additionally, the continuous feeding and pre-heating of billets in continuous flow or with intermediate pause is also possible. Finally, a purely continuous flow operation from the pre-heating phase through the final treatment is also possible. As the pre-heating or pretreatment phase in the pretreatment furnace is adjustable, it is also possible to pass material continuously through the pretreatment furnace into the heat treatment furnace using only one transport device.
By the individual treatment of the material, not only is a uniform quality ensured, but also measures against warping or curling of the billets are made possible. For this purpose it is particularly advantageous if the billets are rotated about their longitudinal axes during the holding, as in princiciple is known from French Pat. No. 1,150,693. Such a rotation appeared to be appropriate for avoidance of warping or curvind also during the cooling following the heat treatment.
If the material is supplied step-by-step, and is pre-heated in stationary condition, then in a preferred apparatus according to the invention, it may be placed in the pre-heating furnace in a predeterminable position. In this connection at least one limit switch for the control of the transport device can be arranged in a position in the preheating furnace, in which the material is placed in the desired manner. In order to be able to pre-heat different billet lengths without waste of energy, in a further developed embodiment of the instant invention, measuring devices are provided for measurement of the length of the material introduced into the pre-heating furnace, and the heating devices are sub-divided into groups, which are controlled by means of the measuring devices as a function of the length of the material.
A particularly suitable arrangement is provided in that between the pre-heating furnace and the holding furnace there is arranged an intermediate transport device, which serves for transference of the material to be treated from a supply device to the pre-heating furnace and from this to the holding furnace. For this purpose the pre-heating furnace and the holding furnace can be arranged with their two transport devices transversely to one another, and then the intermediate transport device suitably works reversibly. The heating arrangements in the furnace consist preferably of burners, the flames of which impinge directly on the material. The holding furnace is preferably heated electrically or with fuel and is a forced air type of furnace.
BRIEF DESCRIPTION OF THE DRAWINGS
For a fuller understanding of the nature and objects of the invention, reference should be had to the following detailed description, taken in connection with the accompanying drawings in which:
FIG. 1 is a schematic view of an apparatus according to the invention with a pre-heating furnace and a successively arranged holding or heat-treatment furnace;
FIG. 2 is a cross-section through a pre-heating furnace which is preferably employed in an apparatus, according to the instant invention;
FIG. 3 is a section along the line 111--111 of FIG. 2;
FIG. 4 is a longitudinal section through a holding furnace which can be employed in the apparatus according to the invention, with a transport device constructed in accordance with the invention;
FIG. 5 is a partial section according to line V--V of FIG. 4;
FIGS. 6a to 6e are transport phases succeeding one another in time, in transporting the material through the heat retaining furnace; and
FIGS. 7 and 8 are, respectively, a longitudinal section of a shower device, and a cross section according to line VIII--VIII of FIG. 7.
DESCRIPTION OF THE PREFERRED EMBODIMENT
In the schematic plan view according to FIG. 1, bars or billets are indicated by the reference numeral 1. From a supply device or a magazine 2, the billets or bars 1 are automatically transferred individually to a transport device 8, which can supply step-by-step, in the direction of the horizontal arrows, into the pre-heating pretreatment furnaces 3 arranged to left and right of it, as seen in FIG. 1. The billets or bars 1 are brought rapidly to full annealing temperature individually in the pre-heating pretreatment furnaces 3 in stationary condition by direct flame impingement by means of burners. Thereafter the individually pre-heated billets are taken out again from the respective pretreatment furnace 3, and are transferred individually in succession from the transport device 8 into a holding or heat treatment furnace 4. This holding furnace is formed as a continuous flow furnace, and operates with circulated hot gas, for example hot air. The full annealing temperature is maintained over the length of the holding furnace, or, in the case where the billets at the entry into the holding furnace have not yet entirely attained the full annealing temperature, is reached after a short travel in the holding furnace.
By alteration of the pre-heating time, that is of the period of time in which the billets 1 are held in the preheating furnaces 3, and by control of the burners, the pre-heating temperature can be adjusted finely and over a wide range, which makes it possible that always a uniform pre-heating of the billets is obtained.
The holding time in the holding or treatment furnace 4 can be varied according to the alloy composition of the billets and the desired structure by alteration of the speed of through travel. The temperature in the holding furnace 4 can be altered, for example by control of the temperature of the hot air gas.
In the holding furnace 4 devices are provided for rotation of the billets 1 about their longitudinal axes, so that these are completely uniformly heated and warping or curving cannot occur or the billets are straightened. The bars, plasticised by the annealing, automatically straighten themselves by reason of their own weight.
The billets 1 are transferred from the exit of the heat retaining furnaces 4 to a cooling station 6, where the billets passing through are cooled individually with water and/or air. At the cooling station 6 there is arranged, as shown in detail in FIGS. 7 and 8, a device for turning the billets during cooling, so that also here there is prevented bending or distortion of the billets due to uniform cooling effect from all sides.
From the cooling station 6 the billets 1 reach a magazine 7, from where they are conveyed to another station for further working.
The separation of pre-heating and heat retaining opens the possibility of individually controlling the temperature and primarily the sequence or transport speed in the pre-heating and heat retaining phase. This leads to a very high flexibility of the whole installation, that means to an optimal adaptability in each case to the different requirements during operation, such as realization of different peak annealing temperatures, desirable in practice, with different alloys, and interrupted operations or operation under part load in adapting to successive devices or to stoppages in the billet supply. By the quick preheating with direct flame impingement the construction of the pre-heating or pretreatment furnace is smaller than before, so that the space need of the whole installation is reduced. The material flow is greatly improved and the quantity of the material flow is increased due to the continuous or quasi-continuous performance.
FIGS. 2 and 3 show a preferred preheating furnace in detail.
The pre-heating furnace has such a length that a billet of the largest size availabe in practice (7-8m) fits into it lengthwise. In the preheating furnace 3 there is a provided double strand or strip conveyor chain 13 with carrier devices 12 mounted thereon for the billets 1 to be pre-heated. The carrier devices 12 reach through a longitudinal slot into a cylindrical furnace chamber 15 formed by two furnace shells 14. The furnace shells are each journalled to swing by their lower ends on a carrier rail 16 and are held together above by spacing members 17. Laterally the furnace shells are supported on the furnace wall by radial supporting bars 18. By removal of the spacing members 17 and slight swinging inwards around the supporting points on the carrier rail 16, the furnace shells 14 can be dismantled without difficulty.
The furnace shells 14 have four radially directed rows of openings 22, into which discharge nozzles 21, of pre-mixed burners 19, 20 are likewise radially directed. The radially directed rows of burners extend over the entire length of the furnace shells 14. In doing so, the lower rows of burners 29 are arranged close to the supporting devices 12 and directed obliquely upwards, while the two upper rows of burners are offset by about 90° to the corresponding lower rows of burners and directed obliquely downwards. The upper rows of burners 19 can be adjusted with respect to the lower rows of burner 20.
Based on the arrangement of the rows of burners 19, 20, during heating of billets 1 or 1' (of smaller diameter) the surfaces for heat transfer are employed in an optimum manner, so that a circularly symmetrical temperature distribution over the cross-section of the billets is achieved. The burner nozzles 21 are at this time differently adjusted in their output, so that the temperature distribution desired in each case is attained.
The carrier devices 12 for the billets 1 or 1' have, at the place where they penetrate into the slot formed between the two furnace shells 14, a shaft which is rectangular in cross-section, which fills up the slot except for a safety spacing necessary for thermal expansion.
The flue gases leave the furnace cavity 15 upwards through the slot formed by the furnace shells 14 and the spacer members 17, and are, together with fresh air, sucked away through a suction fan along the exhaust duct 26. The outer casing 27 serves in this connection at the same time as an air duct for the fresh air sucked in.
The pipes 28 necessary for the mixing and measuring of the combustion gas, as well as a device 29 for measurement of the temperature of the bars 1 or 1', are arranged at the right hand side of the furnace as seen in FIG. 2.
For pre-heating, the billets are pushed into the furnace from the transport device 8 and are taken over by the carrier devices which are moved by the double-run conveyor chain 13. The drive for the double-run conveyor chain is controlled by a limit switch not shown, which turns off the drive when a billet 1 runs against an abutment 30 at one end of the furnace shells 14.
Measuring devices, not shown, arranged at uniform spacings over the length of the furnace shells 14 measure the length of the billet inserted at each moment. These measuring devices control the burners 19 and 20 in groups, so that at each moment only a number of burners corresponding to the length of a billet is actuated for pre-heating. The burners are first switched on, when a corresponding billet 1 has reached the position shown in FIG. 3 against the abutment 30.
With shorter billet lengths, it is also possible that the pre-heating furnace 3 is supplied with a plurality of bars.
With the pre-heating furnace shown, a continuous flow operation is also attainable. The billets 1 in this operation are preheated in moving condition. The drive is, however, preferably intermittent in this case, so that the necessary matching with the following period of annealing in the holding furnace 4 is achieved.
The holding furnace 4 shown in FIG. 4 in longitudinal section is constructed for continuous flow operation and is heated with hot gas, for instance, hot air, which is blown by a radial-axial blower 40 against the billets 1 or 1' which are to be kept hot, and is circulated in the furnace.
The billets lie in saw-tooth-shape depressions 42 with oblique surfaces 42a of stationary beams 44 extending longitudinally through the furnace space 43. The beams 44 are arranged with spaces inbetween, at least two of which have a width x (FIG. 5). In the intermediate spaces so defined there fit lifting beams 45 extending between and parallel to the beams 44. The lifting beams 45 have horizontal flat surface portions 45' for receiving the billets 1 or 1', and these surface portions 45' are limited by prismatic abutments in the form of angle sections 46 welded onto the flat upper surface of the lifting beam. Adjacent angle sections 46 have a spacing at least approximating to the spacing of adjacent depressions 42, and, in the transport direction A, have a small longitudinal extent 1 in comparison with the extent k of the flat surface portions 45', so that round billets 1, 1' of usual diameter can roll on the flat portions 45'. The angle sections 46 serve simply as safety abutments, not normally used, if the billets 1, 1' for any reason, e.g. in the raised condition, are found to be turned, for example by reason of a twist received during lifting. Three lifting pipes 50 of square cross-section engage each lifting beam 45 from below; they are vertically movable but non-rotatingly held in rectangular longitudinal slots 51 on the floor 52 of the heat maintaining furnace. One of these longitudinal slots 51 is shown for better understanding in dot-and-dash lines in FIG. 5 where the floor 52 is omitted.
One possible construction is shown at the right in FIG. 4. Into the lower end of each lifting pipe 50 there is welded a nut 53, which is passed through by a spindle 54 making screw-threaded engagement therewith. Each spindle 54 carries at its lower end a bevel pinion 55 which meshes with a bevel pinion shifted by 90°. All bevel pinions 56 are arranged on a joint horizontal shaft 57 which is actuatable by a drive motor 58 in order to start moving the lifting pipes 50 and therewith the lifting beams 45.
The shaft is journalled in housings 47, each associated with a corresponding spindle 54, lifting pipe 50, and bevel pinion pair 55, 56. The motor 58 and the housing 47 are mounted on a carriage 59 which operates on rollers 60. This carriage is movable, along the ground or on rails 62, by a double-acting fluid cylinder 61 through a horizontal stroke y which corresponds approximately to the horizontal component of the length of the oblique surfaces 42a. The vertical travel z of the lifting beam 45 which is produceable via the above described lifting device by the motor 58 is made of such extent that, in lowered condition, the lifting beam 45 with the angle sections 46 can be freely pushed beneath the billets 1, 1', and in the raised condition the billets 1, 1' lying on the lifting beams 45 do not engage on the oblique surfaces 42a of the saw-tooth depressions 42 during horizontal transport.
In a preferred second embodiment (illustrated in FIG. 4 at the left hand spindle gear), the nut 53 of each spindle gear is movably held in the housing 47 and tightly connected with the lower end of the lifting pipe 50 and not turnable, but vertically movable in the housing 47 and shiftable in its axial direction. All component parts of the spindle gear are in this case lodged and mounted in the housing 47, and the lifting pipe 50 does no longer contain any movable parts of the drive gear. This is advantageous for mounting and maintenance.
The transport of the billets 1 by means of the transport device shown in FIGS. 4 and 5 will now be described with reference to FIGS. 6a to 6e.
In the rest position of the lifting beam 45 (FIGS. 4 and 6a), the depressions between the angle profiles 46 are slightly shifted ahead of the depressions 42. In principle, the transport device would also function without the angle profiles 46, that means with lifting beams having a horizontal flat surface.
As can be seen from FIG. 6a, a billet 1 with larger diameter lies in the depression 42 with its center offset against the transport direction A. This arises from the slight inclination of the inclined surface 42a in comparison to the opposite surface (which has no reference numeral).
In the rest position according to FIG. 6a, the billets lie in the depressions 42 of the stationary beams 44. The lifting beams 45 lie below the stationary beams. By actuation of the spindle gears, the lifting beams are now moved upwards in lifting direction B, engaging the billets 1 and lifting these upwards from the depressions 42 through the distance z (FIG. 6b).
After completion of this lifting movement, each lifting beam 45 is moved to the right as shown in FIG. 6c, by means of the drive cylinder 61, through the distance y in transport direction A. During this movement the billets 1 move to above the oblique surface 42a of the next following depressions 42 in transport direction. In this way one ensures that even bars which are curved before heat treatment can be carried without trouble through the holding surface.
After completed advance of the beam in the transport direction A, the spindle gear is again actuated, but now in direction B' which is counter to the lifting direction B. The speed of this movement is controlled in such a way that the bars are gently lowered onto the oblique surfaces 42a of the stationary beams (FIG. 6d). The bars 1 roll now due to their own weight from the oblique surfaces 42a into the depressions 42. During this motion, they turn about an angle (FIG. 6e). However, this rolling off movement is controlled by the lowering movement of the lifting beam in the direction B', that means braked to such an extent that no impact blow is created at arrival in the depression 42 that would damage the shape and surface of the bars which are annealed to plasticity.
The length of the oblique surfaces 42a is so proportioned that the bars reach the depressions 42 with the circumferential section turned about the angle, that is at each next following depression with an other section, so that in each case these other sections come in contact with the circulated hot gas or the circulated hot air. Hereby the bars in all their areas may be maintained on a very uniform temperature. The rolling off of the bars on the oblique surfaces 42a controlled by the downward movement of the lifting beam 45 leads to the automatic straightening of the bars due to their own weight for eliminating curvatures that might have occurred for any reasons.
In the manner described, the bars are transported through the heat treatment furnace avoiding any wedging-in between the lifting beams 45 and the stationary beams 44, so that the risk of damaging the bars is practically eliminated.
Simultaneously with the lifting movement of the lifting beams 45, the furnace doors 48, 49, are opened for admitting or discharging the bars 1 or 1'. The furnace doors 48, 49 are shown in FIG. 4 in broken lines in open position. The loading and emptying of the holding furnace 4 can also take place in the longitudinal direction of the billets 1 by doors provided on one side of the holding furnace, in which case the doors 48, 49 are omitted.
The cooling station shown in FIGS. 7 and 8 has a spray chamber 70 on the upper wall 71 of which there is mounted an internal closed water channel comprising several segments 72 aligned in succession in the longitudinal direction. Each segment 72 of the water channel has a separate water supply pipe 73 and in its lower wall is provided with spray holes 74 which are arranged close to one another in a row in the longitudinal direction of the water channel. Below the water channel a shaft 75, aligned axles 76, and a shaft 77 extend through the spray chamber, parallel to one another. The shafts 75, 77 and the axes 76 are all supported in bearing blocks 78, the shafts 75, 77 and the axles 77 being movable in journals 79, 80.
The shaft 75 is driven by a drive motor 81 arranged outside the shower chamber 70 and carries rolls 82 arranged on it movably at regular distances.
The axles 76 are shiftably mounted to rock about the shaft 77 by means of at least two rockers 84. In the normal position shown in FIG. 7, the axles 76 lie in the same horizontal plane as the shaft 75 and from it at a distance from it adjusted adjusted to the measurements of the billets 1 and 1' to be worked, which distance is smaller than the bar diameter.
On the axles 76 there are turnably mounted rolls 83 of the same diameter as the rolls 82 of the shaft 75. The rolls 82, 83 are associated in pairs, and form a prismatic recess for the billets 1 or 1'. The rockers 84 supporting the shaft 76 are rigidly connected to the axle 77. This shaft 77 is shiftable by one or two pivoted cylinders 85 and a crank arm 86 to the shaft 77 and pivoted to the piston rod 87 of the cylinder 85. The rocker 84 is shown in rotated positon in dot-and-dash lines.
There is furthermore provided at least one transfer arm 88 to feed the bars 1 into the spray device. This arm 88 is shiftable by a cylinder 89 with a piston rod 94, between the two positions shown in full and in dot-and-dash lines, about the axis of the shaft 75.
In the lower portion of the spray chamber 70 there is a collecting tub or reservoir 90 from the deepest location of which there issues a discharge pipe 91 directed vertically downwards.
The spray device described operates as follows:
A hot billet 1 or 1' coming from the heat maintaining furnace is set in motion over a roller conveyor 92 arranged alongside the spray device. The cylinder 89 has been actuated, so that the transfer arm 88 lies below the track of the billet 1. When the conveyor 92 stops, the cylinder 89 is extended and hence the transfer arm 88 lifted raising the billet 1 from the position shown in dot-dash lines, so that the billet may roll along the flat surface 93 of the transfer arm 88 which is now slightly sloping towards the rolls 82,83 and thereby may reach the prismatic recess between the rolls 82, 83. Now there is sprayed through the sprayhole 74 water onto the bar 1 or 1'. As the sprayholes 74 are arranged over the whole length of the bar at small distances from one another, there is obtained a very uniform cooling of the bar. For emitting the cooled bar, the piston 87 of the cylinder 85 is extended, after previous pulling in of the cylinder 89, and therewith shifting the feed drop 88 into the solidly placed lower position shown, so that the rockers 84 and therewith the axle 76 move from the solid into the dot-dash-line position. This moves the bar out of the prismatic seat between the rolls 82, 83 onto the now outwardly slanted surface 93 of the feed drop 88, wherefrom it rolls down onto the roller bed 92 for further handling.
We wish it to be understood that we do not desire to be limited to the exact details of construction shown and described, for obvious modifications will occur to a person skilled in the art. | Apparatus for heat treatment of metal pieces such as billets, ingots, bars and the like, by pre-heating using direct flame impingement in a pre-heating furnace and then transferance into a holding furnace using forced hot air circulation where the metal pieces are held for the time required at the desired heat treatment temperature. | 5 |
RELATED APPLICATIONS
[0001] This application is a continuation of U.S. patent application Ser. No. 14/081,317 filed on Nov. 15, 2013, which is a continuation of U.S. patent application Ser. No. 13/941,431 filed on Jul. 12, 2013, now U.S. Pat. No. 8,589,599, which is a continuation of U.S. patent application Ser. No. 13/430,650 filed on Mar. 26, 2012, now U.S. Pat. No. 8,675,590, which is a continuation of U.S. patent application Ser. No. 12/699,846 filed on Feb. 3, 2010, now U.S. Pat. No. 8,149,829, which is a continuation of U.S. patent application Ser. No. 11/728,246 filed on Mar. 23, 2007, now U.S. Pat. No. 7,756,129, which is a continuation of U.S. patent application Ser. No. 10/894,406 filed on Jul. 19, 2004, now U.S. Pat. No. 7,218,633, which is a continuation of U.S. patent application Ser. No. 09/535,591 filed on Mar. 27, 2000, now U.S. Pat. No. 6,804,232, which is related to U.S. patent application Ser. No. 09/536,191 filed on Mar. 27, 2000, all of which are incorporated herein by reference in their entirety for all purposes.
BACKGROUND AND FIELD OF THE INVENTION
[0002] A. Field of the Invention
[0003] The present invention relates to networking and, more particularly, to a data network.
[0004] B. Description of Related Art
[0005] Over the last decade, the size and power consumption of digital electronic devices has been progressively reduced. For example, personal computers have evolved from laptops and notebooks into hand-held or belt-carriable devices commonly referred to as personal digital assistants (PDAs). One area of carriable devices that has remained troublesome, however, is the coupling of peripheral devices or sensors to the main processing unit of the PDA. Generally, such coupling is performed through the use of connecting cables. The connecting cables restrict the handling of a peripheral in such a manner as to lose many of the advantages inherent in the PDA's small size and light weight. For a sensor, for example, that occasionally comes into contact with the PDA, the use of cables is particularly undesirable.
[0006] While some conventional systems have proposed linking a keyboard or a mouse to a main processing unit using infrared or radio frequency (RF) communications, such systems have typically been limited to a single peripheral unit with a dedicated channel of low capacity.
[0007] Based on the foregoing, it is desirable to develop a low power data network that provides highly reliable bidirectional data communication between a host or server processor unit and a varying number of peripheral units and/or sensors while avoiding interference from nearby similar systems.
SUMMARY OF THE INVENTION
[0008] Systems and methods consistent with the present invention address this need by providing a wireless personal area network that permits a host unit to communicate with peripheral units with minimal interference from neighboring systems.
[0009] A system consistent with the present invention includes a hub device and at least one unattached peripheral device. The unattached peripheral device transmits an attach request to the hub device with a selected address, receives a new address from the hub device to identify the unattached peripheral device, and communicates with the hub device using the new address.
[0010] In another implementation consistent with the present invention, a method for attaching an unattached peripheral device to a network having a hub device connected to multiple peripheral devices, includes receiving an attach request from the unattached peripheral device, the attach request identifying the unattached peripheral device to the hub device; generating a new address to identify the unattached peripheral device in response to the received attach request; sending the new address to the unattached peripheral device; and sending a confirmation message to the unattached peripheral device using the new address to attach the unattached peripheral device.
[0011] In yet another implementation consistent with the present invention, a method for attaching an unattached peripheral device to a network having a hub device connected to a set of peripheral devices, includes transmitting an attach request with a selected address to the hub device; receiving a new address from the hub device to identify the unattached peripheral device; and attaching to the network using the new address.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate an embodiment of the invention and, together with the description, explain the invention. In the drawings:
[0013] FIG. 1 is a diagram of a personal area network (PAN) in which systems and methods consistent with the present invention may be implemented;
[0014] FIG. 2 is a simplified block diagram of the Hub of FIG. 1 ;
[0015] FIG. 3 is a simplified block diagram of a PEA of FIG. 1 ;
[0016] FIG. 4 is a block diagram of a software architecture of a Hub or PEA in an implementation consistent with the present invention;
[0017] FIG. 5 is an exemplary diagram of communication processing by the layers of the software architecture of FIG. 4 ;
[0018] FIG. 6 is an exemplary diagram of a data block architecture within the DCL of the Hub and PEA in an implementation consistent with the present invention;
[0019] FIG. 7A is a detailed diagram of an exemplary stream usage plan in an implementation consistent with the present invention;
[0020] FIG. 7B is a detailed diagram of an exemplary stream usage assignment in an implementation consistent with the present invention;
[0021] FIG. 8 is an exemplary diagram of a time division multiple access (TDMA) frame structure in an implementation consistent with the present invention;
[0022] FIG. 9A is a detailed diagram of activity within the Hub and PEA according to a TDMA plan consistent with the present invention;
[0023] FIG. 9B is a flowchart of the Hub activity of FIG. 9A ;
[0024] FIG. 9C is a flowchart of the PEA activity of FIG. 9A ;
[0025] FIGS. 10A and 10B are high-level diagrams of states that the Hub and PEA traverse during a data transfer in an implementation consistent with the present invention;
[0026] FIGS. 11 and 12 are flowcharts of Hub and PEA attachment processing, respectively, consistent with the present invention; and
[0027] FIG. 13 is a flowchart of PEA detachment and reattachment processing consistent with the present invention.
DETAILED DESCRIPTION
[0028] The following detailed description of the invention refers to the accompanying drawings. The same reference numbers in different drawings identify the same or similar elements. Also, the following detailed description does not limit the invention. Instead, the scope of the invention is defined by the appended claims.
[0029] Systems and methods consistent with the present invention provide a wireless personal area network that permits a host device to communicate with a varying number of peripheral devices with minimal interference from neighboring networks. The host device uses tokens to manage all of the communication in the network, and automatic attachment and detachment mechanisms to communicate with the peripheral devices.
Network Overview
[0030] A Personal Area Network (PAN) is a local network that interconnects computers with devices (e.g., peripherals, sensors, actuators) within their immediate proximity. These devices may be located nearby and may frequently or occasionally come within range and go out of range of the computer. Some devices may be embedded within an infrastructure (e.g., a building or vehicle) so that they can become part of a PAN as needed.
[0031] A PAN, in an implementation consistent with the present invention, has low power consumption and small size, supports wireless communication without line-of-sight limitations, supports communication among networks of multiple devices (over 100 devices), and tolerates interference from other PAN systems operating within the vicinity. A PAN can also be easily integrated into a broad range of simple and complex devices, is low in cost, and is capable of being used worldwide.
[0032] FIG. 1 is a diagram of a PAN 100 consistent with the present invention. The PAN 100 includes a single Hub device 110 surrounded by multiple Personal Electronic Accessory (PEA) devices 120 configured in a star topology. Other topologies may also be possible. Each device is identified by a Media Access (MAC) address.
[0033] The Hub 110 orchestrates all communication in the PAN 100 , which consists of communication between the Hub 110 and one or more PEA(s) 120 . The Hub 110 manages the timing of the network, allocates available bandwidth among the currently attached PEAs 120 participating in the PAN 100 , and supports the attachment, detachment, and reattachment of PEAs 120 to and from the PAN 100 .
[0034] The Hub 110 may be a stationary device or may reside in some sort of wearable computer, such as a simple pager-like device, that may move from peripheral to peripheral. The Hub 110 could, however, include other devices.
[0035] The PEAs 120 may vary dramatically in terms of their complexity. A very simple PEA might include a movement sensor having an accelerometer, an 8-bit microcontroller, and a PAN interface. An intermediate PEA might include a bar code scanner and its microcontroller. More complex PEAs might include PDAs, cellular telephones, or even desktop PCs and workstations. The PEAs may include stationary devices located near the Hub and/or portable devices that move to and away from the Hub.
[0036] The Hub 110 and PEAs 120 communicate using multiplexed communication over a predefined set of streams. Logically, a stream is a one-way communications link between one PEA 120 and its Hub 110 . Each stream has a predetermined size and direction. The Hub 110 uses stream numbers to identify communication channels for specific functions (e.g., data and control).
[0037] The Hub 110 uses MAC addresses to identify itself and the PEAs 120 . The Hub 110 uses its own MAC address to broadcast to all PEAs 120 . The Hub 110 might also use MAC addresses to identify virtual PEAs within any one physical PEA 120 . The Hub 110 combines a MAC address and a stream number into a token, which it broadcasts to the PEAs 120 to control communication through the network 100 . The PEA 120 responds to the Hub 110 if it identifies its own MAC address or the Hub MAC address in the token and if the stream number in the token is active for the MAC address of the PEA 120 .
Exemplary Hub Device
[0038] FIG. 2 is a simplified block diagram of the Hub 110 of FIG. 1 . The Hub 110 may be a battery-powered device that includes Hub host 210 , digital control logic 220 , radio frequency (RF) transceiver 230 , and an antenna 240 .
[0039] Hub host 210 may include anything from a simple microcontroller to a high performance microprocessor. The digital control logic (DCL) 220 may include a controller that maintains timing and coordinates the operations of the Hub host 210 and the RF transceiver 230 . The DCL 220 is specifically designed to minimize power consumption, cost, and size of the Hub 110 . Its design centers around a time-division multiple access (TDMA)-based network access protocol that exploits the short range nature of the PAN 100 . The Hub host 210 causes the DCL 220 to initialize the network 100 , send tokens and messages, and receive messages. Responses from the DCL 220 feed incoming messages to the Hub host 210 .
[0040] The RF transceiver 230 includes a conventional RF transceiver that transmits and receives information via the antenna 240 . The RF transceiver 230 may alternatively include separate transmitter and receiver devices controlled by the DCL 220 . The antenna 240 includes a conventional antenna for transmitting and receiving information over the network.
[0041] While FIG. 2 shows the exemplary Hub 110 as consisting of three separate elements, these elements may be physically implemented in one or more integrated circuits. For example, the Hub host 210 and the DCL 220 , the DCL 220 and the RF transceiver 230 , or the Hub host 210 , the DCL 220 , and the RF transceiver 230 may be implemented as a single integrated circuit or separate integrated circuits. Moreover, one skilled in the art will recognize that the Hub 110 may include additional elements that aid in the sending, receiving, and processing of data.
Exemplary PEA Device
[0042] FIG. 3 is a simplified block diagram of the PEA 120 . The PEA 120 may be a battery-powered device that includes a PEA host 310 , DCL 320 , RF transceiver 330 , and an antenna 340 . The PEA host 310 may include a sensor that responds to information from a user, an actuator that provides output to the user, a combination of a sensor and an actuator, or more complex circuitry, as described above.
[0043] The DCL 320 may include a controller that coordinates the operations of the PEA host 310 and the RF transceiver 330 . The DCL 320 sequences the operations necessary in establishing synchronization with the Hub 110 , in data communications, in coupling received information from the RF transceiver 330 to the PEA host 310 , and in transmitting data from the PEA host 310 back to the Hub 110 through the RF transceiver 330 .
[0044] The RF transceiver 330 includes a conventional RF transceiver that transmits and receives information via the antenna 340 . The RF transceiver 330 may alternatively include separate transmitter and receiver devices controlled by the DCL 320 . The antenna 340 includes a conventional antenna for transmitting and receiving information over the network.
[0045] While FIG. 3 shows the exemplary PEA 120 as consisting of three separate elements, these elements may be physically implemented in one or more integrated circuits. For example, the PEA host 310 and the DCL 320 , the DCL 320 and the RF transceiver 330 , or the PEA host 310 , the DCL 320 , and the RF transceiver 330 may be implemented as a single integrated circuit or separate integrated circuits. Moreover, one skilled in the art will recognize that the PEA 120 may include additional elements that aid in the sending, receiving, and processing of data.
Exemplary Software Architecture
[0046] FIG. 4 is an exemplary diagram of a software architecture 400 of the Hub 110 in an implementation consistent with the present invention. The software architecture 400 in the PEA 120 has a similar structure. The software architecture 400 includes several distinct layers, each designed to serve a specific purpose, including: (1) application 410 , (2) link layer control (LLC) 420 , (3) network interface (NI) 430 , (4) link layer transport (LLT) 440 , (5) link layer driver (LLD) 450, and (6) DCL hardware 460 . The layers have application programming interfaces (APIs) to facilitate communication with lower layers. The LLD 450 is the lowest layer of software. Each layer may communicate with the next higher layer via procedural upcalls that the higher layer registers with the lower layer.
[0047] The application 410 may include any application executing on the Hub 110 , such as a communication routine. The LLC 420 performs several miscellaneous tasks, such as initialization, attachment support, bandwidth control, and token planning. The LLC 420 orchestrates device initialization, including the initialization of the other layers in the software architecture 400 , upon power-up.
[0048] The LLC 420 provides attachment support by providing attachment opportunities for unattached PEAs to attach to the Hub 110 so that they can communicate, providing MAC address assignment, and initializing an NI 430 and the layers below it for communication with a PEA 120 . The LLC 420 provides bandwidth control through token planning. Through the use of tokens, the LLC 420 allocates bandwidth to permit one PEA 120 at a time to communicate with the Hub 110 .
[0049] The NI 430 acts on its own behalf, or for an application 410 layer above it, to deliver data to the LLT 440 beneath it. The LLT 440 provides an ordered, reliable “snippet” (i.e., a data block) delivery service for the NI 430 through the use of encoding (e.g., 16-64 bytes of data plus a cyclic redundancy check (CRC)) and snippet retransmission. The LLT 440 accepts snippets, in order, from the NI 430 and delivers them using encoded status blocks (e.g., up to 2 bytes of status information translated through Forward Error Correction (FEC) into 6 bytes) for acknowledgments (ACKs).
[0050] The LLD 450 is the lowest level of software in the software architecture 400 . The LLD 450 interacts with the DCL hardware 460 . The LLD 450 initializes and updates data transfers via the DCL hardware 460 as it delivers and receives data blocks for the LLT 440 , and processes hardware interrupts. The DCL hardware 460 is the hardware driven by the LLD 450 .
[0051] FIG. 5 is an exemplary diagram of communication processing by the layers of the software architecture 400 of FIG. 4 . In FIG. 5 , the exemplary communications involve the transmission of a snippet from one node to another. This example assumes that the sending node is the Hub 110 and the receiving node is a PEA 120 . Processing begins with the NI 430 of the Hub 110 deciding to send one or more bytes (but no more than will fit) in a snippet. The NI 430 exports the semantics that only one transaction is required to transmit these bytes to their destination (denoted by “(1)” in the figure). The NI 430 sends a unique identifier for the destination PEA 120 of the snippet to the LLT 440 . The LLT 440 maps the PEA identifier to the MAC address assigned to the PEA 120 by the Hub 110 .
[0052] The LLT 440 transmits the snippet across the network to the receiving device. To accomplish this, the LLT 440 adds header information (to indicate, for example, how many bytes in the snippet are padded bytes) and error checking information to the snippet, and employs reverse-direction status/acknowledgment messages and retransmissions. This is illustrated in FIG. 5 by the bidirectional arrow between the LLT 440 layers marked with “(n+m).” The number n of snippet transmissions and the number m of status transmissions in the reverse direction are mostly a function of the amount of noise in the wireless communication, which may be highly variable. The LLT 440 may also encrypt portions or all of the snippet using known encryption technology.
[0053] The LLT 440 uses the LLD 450 to provide a basic block and stream-oriented communications service, isolating the DCL 460 interface from the potentially complex processing required of the LLT 440 . The LLT 440 uses multiple stream numbers to differentiate snippet and status blocks so that the LLD 450 need not know which blocks contain what kind of content. The LLD 450 reads and writes the hardware DCL 460 to trigger the transmission and reception of data blocks. The PEA LLT 440 , through the PEA LLD 450 , instructs the PEA DCL 460 which MAC address or addresses to respond to, and which stream numbers to respond to for each MAC address. The Hub LLT 440 , through the Hub LLD 450 , instructs the Hub DCL 460 which MAC addresses and stream numbers to combine into tokens and transmit so that the correct PEA 120 will respond. The Hub DCL 460 sends and receives (frequently in a corrupted form) the data blocks across the RF network via the Hub RF transceiver 230 ( FIG. 2 ).
[0054] The Hub LLT 440 employs FEC for status, checksums and error checking for snippets, and performs retransmission control for both to ensure that each snippet is delivered reliably to its client (e.g., PEA LLT 440 ). The PEA LLT 440 delivers snippets in the same order that they were sent by the Hub NI 430 to the PEA NI 430 . The PEA NI 430 takes the one or more bytes sent in the snippets and delivers them in order to the higher-level application 410 , thereby completing the transmission.
Exemplary DCL Data Block Architecture
[0055] FIG. 6 is an exemplary diagram of a data block architecture 600 within the DCL of the Hub 110 and the PEA 120 . The data block 600 contains a MAC address 610 designating a receiving or sending PEA 120 , a stream number 620 for the communication, and a data buffer 630 which is full when sending and empty when receiving. As will be described later, the MAC address 610 and stream number 620 form the contents of a token 640 . When the LLD 450 reads from and writes to the hardware DCL 46 . 0 , the LLD 450 communicates the MAC address 610 and stream number 620 with the data buffer 630 . When a PEA 120 receives a data block, the DCL 460 places the MAC address 610 and stream number 620 contained in the preceding token 640 in the data block 600 to keep track of the different data flows.
Exemplary Stream Architecture
[0056] The LLD 450 provides a multi-stream data transfer service for the LLT 440 . While the LLT 440 is concerned with data snippets and status/acknowledgements, the LLD 450 is concerned with the size of data blocks and the direction of data transfers to and from the Hub 110 .
[0057] FIG. 7A is a detailed diagram of an exemplary stream usage plan 700 in an implementation consistent with the present invention. A single stream usage plan may be predefined and used by the Hub 110 and all PEAs 120 . The PEA 120 may have a different set of active streams for each MAC address it supports, and only responds to a token that specifies a MAC address of the PEA 120 and a stream that is active for that MAC address. In an implementation consistent with the present invention, every PEA 120 may support one or more active Hub-to-PEA streams associated with the Hub's MAC address.
[0058] The stream usage plan 700 includes several streams 710 - 740 , each having a predefined size and data transfer direction. The plan 700 may, of course, have more or fewer entries and may accommodate more than the two data block sizes shown in the figure. In the plan 700 , streams 0-2 ( 710 ) are used to transmit the contents of small data blocks from the PEA 120 to the Hub 110 . Streams 3-7 ( 720 ) are used to transmit the contents of larger data blocks from the PEA 120 to the Hub 110 . Streams 8-10 ( 730 ), on the other hand, are used to transmit the contents of small data blocks from the Hub 110 to the PEA 120 . Streams 11-15 ( 740 ) are used to transmit the contents of larger data blocks from the Hub 110 to the PEA 120 .
[0059] To avoid collisions, some of the streams are reserved for PEAs desiring to attach to the network and the rest are reserved for PEAs already attached to the network. With such an arrangement, a PEA 120 knows whether and what type of communication is scheduled by the Hub 110 based on a combination of the MAC address 610 and the stream number 620 .
[0060] FIG. 7B is a detailed diagram of an exemplary stream usage assignment by the LLT 440 in an implementation consistent with the present invention. The LLT 440 assigns different streams to different communication purposes, reserving the streams with small block size for status, and using the streams with larger block size for snippets. For example, the LLT 440 may use four streams (4-7 and 12-15) for the transmission of snippets in each direction, two for odd parity snippets and two for even parity snippets. In other implementations consistent with the present invention, the LLT 440 uses different numbers of streams of each parity and direction.
[0061] The use of more than one stream for the same snippet allows a snippet to be sent in more than one form. For example, the LLT 440 may send a snippet in its actual form through one stream and in a form with bytes complemented and in reverse order through the other stream. The alternating use of different transformations of a snippet more evenly distributes transmission errors among the bits of the snippet as they are received, and hence facilitates the reconstruction of a snippet from multiple corrupted received versions. The receiver always knows which form of the snippet was transmitted based on its stream number.
[0062] The LLT 440 partitions the streams into two disjoint subsets, one for use with Hub 110 assigned MAC addresses 750 and the other for use with attaching PEAs' self-selected MAC addresses (AMACs) 760 . Both the LLT 440 and the LLD 450 know the size and direction of each stream, but the LLT 450 is responsible for determining how the streams are used, how MAC numbers are assigned and used, and assuring that no two PEAs 120 respond to the same token (containing a MAC address and stream number) transmitted by the Hub 110 . One exception to this includes the Hub's use of its MAC address to broadcast its heartbeat 770 (described below) to all PEAs 120 .
Exemplary Communication
[0063] FIG. 8 is an exemplary diagram of a TDMA frame structure 800 of a TDMA plan consistent with the present invention. The TDMA frame 800 starts with a beacon 810 , and then alternates token broadcasts 820 and data transfers 830 . The Hub 110 broadcasts the beacon 810 at the start of each TDMA frame 800 . The PEAs 120 use the beacon 810 , which may contain a unique identifier of the Hub 110 , to synchronize to the Hub 110 .
[0064] Each token 640 ( FIG. 6 ) transmitted by the Hub 110 in a token broadcast 820 includes a MAC address 610 ( FIG. 6 ) and a stream number 620 for the data buffer 630 transfer that follows. The MAC address 610 and stream number 620 in the token 640 together specify a particular PEA 120 to transmit or receive data, or, in the case of the Hub's MAC address 610 , specify no, many, or all PEAs to receive data from the Hub 110 (depending on the stream number). The stream number 620 in the token 640 indicates the direction of the data transfer 830 (Hub 110 to PEA 120 or PEA 120 to Hub 110 ), the number of bytes to be transferred, and the data source (for the sender) and the appropriate empty data block (for the receiver).
[0065] The TDMA plan controls the maximum number of bytes that can be sent in a data transfer 830 . Not all of the permitted bytes need to be used in the data transfer 830 , however, so the Hub 110 may schedule a status block in the initial segment of a TDMA time interval that is large enough to send a snippet. The Hub 110 and PEA 120 treat any left over bytes as no-ops to mark time. Any PEA 120 not involved in the data transfer uses all of the data transfer 830 bytes to mark time while waiting for the next token 640 . The PEA 120 may also power down non-essential circuitry at this time to reduce power consumption.
[0066] FIG. 9A is an exemplary diagram of communication processing for transmitting a single data block from the Hub 110 to a PEA 120 according to the TDMA plan of FIG. 8 . FIGS. 9B and 9C are flowcharts of the Hub 110 and PEA 120 activities, respectively, of FIG. 9A . The reference numbers in FIG. 9A correspond to the flowchart steps of FIGS. 9B and 9C .
[0067] With regard to the Hub activity, the Hub 110 responds to a token command in the TDMA plan [step 911 ] ( FIG. 9B ) by determining the location of the next data block 600 to send or receive [step 912 ]. The Hub 110 reads the block's MAC address 610 and stream number 620 [step 913 ] and generates a token 640 from the MAC address and stream number using FEC [step 914 ]. The Hub 110 then waits for the time for sending a token 640 in the TDMA plan (i.e., a token broadcast 820 in FIG. 8 ) [step 915 ] and broadcasts the token 640 to the PEAs 120 [step 916 ]. If the stream number 620 in the token 640 is zero (i.e., a NO-DATA-TRANSFER token), no PEA 120 will respond and the Hub 110 waits for the next token command in the TDMA plan [step 911 ].
[0068] If the stream number 620 is non-zero, however, the Hub 110 determines the size and direction of the data transmission from the stream number 620 and waits for the time for sending the data in the TDMA plan (i.e., a data transfer 830 ) [step 917 ]. Later, when instructed to do so by the TDMA plan (i.e., after the PEA 120 identified by the MAC address 610 has had enough time to prepare), the Hub 110 transmits the contents of the data buffer 630 [step 918 ]. The Hub 110 then prepares for the next token command in the TDMA plan [step 919 ].
[0069] With regard to the PEA activity, the PEA 120 reaches a token command in the TDMA plan [step 921 ] ( FIG. 9C ). The PEA 120 then listens for the forward error-corrected token 640 , having a MAC address 610 and stream number 620 , transmitted by the Hub 110 [step 922 ]. The PEA 120 decodes the MAC address from the forward error-corrected token [step 923 ] and, if it is not the PEA's 120 MAC address, sleeps through the next data transfer 830 in the TDMA plan [step 924 ]. Otherwise, the PEA 120 also decodes the stream number 620 from the token 640 .
[0070] All PEAs 120 listen for the Hub heartbeat that the Hub 110 broadcasts with a token containing the Hub's MAC address 610 and the heartbeat stream 770 . During attachment (described in more detail below), the PEA 120 may have two additional active MAC addresses 610 , the one it selected for attachment and the one the Hub 110 assigned to the PEA 120 . The streams are partitioned between these three classes of MAC addresses 610 , so the PEA 120 may occasionally find that the token 640 contains a MAC address 610 that the PEA 120 supports, but that the stream number 620 in the token 640 is not one that the PEA 120 supports for this MAC address 610 . In this case, the PEA 120 sleeps through the next data transfer 830 in the TDMA plan [step 924 ].
[0071] Since the PEA 120 supports more than one MAC address 610 , the PEA 120 uses the MAC address 610 and the stream number 620 to identify a suitable empty data block [step 925 ]. The PEA 120 writes the MAC address 610 and stream number 620 it received in the token 640 from the Hub 110 into the data block [step 926 ]. The PEA 120 then determines the size and direction of the data transmission from the stream number 620 and waits for the transmission of the data buffer 630 contents from the Hub 110 during the next data transfer 830 in the TDMA plan [step 927 ]. The PEA 120 stores the data in the data block [step 928 ], and then prepares for the next token command in the TDMA plan [step 929 ].
[0072] FIGS. 9A-9C illustrate communication of a data block from the Hub 110 to a PEA 120 . When the PEA 120 transfers a data block to the Hub 110 , similar steps occur except that the Hub 110 first determines the next data block to receive (with its MAC address 610 and stream number 620 ) and the transmission of the data buffer 630 contents occurs in the opposite direction. The Hub 110 needs to arrange in advance for receiving data from PEAs 120 by populating the MAC address 610 and stream number 620 into data blocks with empty data buffers 630 , because the Hub 110 generates the tokens for receiving data as well as for transmitting data.
[0073] FIGS. 10A and 10B are high-level diagrams of the states that the Hub 110 and PEA 120 LLT 440 ( FIG. 4 ) go through during a data transfer in an implementation consistent with the present invention. FIG. 10A illustrates states of a Hub-to-PEA transfer and FIG. 10B illustrates states of a PEA-to-Hub transfer.
[0074] During the Hub-to-PEA transfer ( FIG. 10A ), the Hub 110 cycles through four states: fill, send even parity, fill, and send odd parity. The fill states indicate when the NI 430 ( FIG. 4 ) may fill a data snippet. The even and odd send states indicate when the Hub 110 sends even numbered and odd numbered snippets to the PEA 120 . The PEA 120 cycles through two states: want even and want odd. The two states indicate the PEA's 120 desire for data, with ‘want even’ indicating that the last snippet successfully received had odd parity. The PEA 120 communicates its current state to the Hub 110 via its status messages (i.e., the state changes serve as ACKs). The Hub 110 waits for a state change in the PEA 120 before it transitions to its next fill state.
[0075] During the PEA-to-Hub transfer ( FIG. 10B ), the Hub 110 cycles through six states: wait/listen for PEA-ready-to-send-even status, read even, send ACK and listen for status, wait/listen for PEA-ready-to-send-odd status, read odd, and send ACK and listen for status. According to this transfer, the PEA 120 cannot transmit data until the Hub 110 requests data, which it will only do if it sees from the PEA's status that the PEA 120 has the next data block ready.
[0076] The four listen for status states schedule when the Hub 110 asks to receive a status message from the PEA 120 . The two ‘send ACK and listen for status’ states occur after successful receipt of a data block by the Hub 110 , and in these two states the Hub 110 schedules both the sending of Hub status to the PEA 120 and receipt of the PEA status. The PEA status informs the Hub 110 when the PEA 120 has successfully received the Hub 110 status and has transitioned to the next ‘fill’ state.
[0077] Once the PEA 120 has prepared its next snippet, it changes its status to ‘have even’ or ‘have odd’ as appropriate. When the Hub 110 detects that the PEA 120 has advanced to the fill state or to ‘have even/odd,’ it stops scheduling the sending of Hub status (ACK) to the PEA 120 . If the Hub 110 detects that the PEA 120 is in the ‘fill’ state, it transitions to the following ‘listen for status’ state. If the PEA 120 has already prepared a new snippet for transmission by the time the Hub 110 learns that its ACK was understood by the PEA 120 , the Hub 110 skips the ‘listen for status’ state and moves immediately to the next appropriate ‘read even/odd’ state. In this state, the Hub 110 receives the snippet from the PEA 120 .
[0078] The PEA 120 cycles through four states: fill, have even, fill, and have odd (i.e., the same four states the Hub 110 cycles through when sending snippets). The fill states indicate when the NI 430 ( FIG. 4 ) can fill a data snippet. During the fill states, the PEA 110 sets its status to ‘have nothing to send.’ The PEA 120 does not transition its status to ‘have even’ or ‘have odd’ until the next snippet is filled and ready to send to the Hub 110 . These two status states indicate the parity of the snippet that the PEA 120 is ready to send to the Hub 110 . When the Hub 110 receives a status of ‘have even’ or ‘have odd’ and the last snippet it successfully received had the opposite parity, it schedules the receipt of data, which it thereafter acknowledges with a change of status that it sends to the PEA 120 .
Exemplary Attachment Processing
[0079] The Hub 110 communicates with only attached PEAs 120 that have an assigned MAC address 610 . An unattached PEA can attach to the Hub 110 when the Hub 110 gives it an opportunity to do so. Periodically, the Hub 110 schedules attachment opportunities for unattached PEAs that wish to attach to the Hub 110 , using a small set of attach MAC (AMAC) addresses and a small set of streams dedicated to this purpose.
[0080] After selecting one of the designated AMAC addresses 610 at random to identify itself and preparing to send a small, possibly forward error-corrected, “attach-interest” message and a longer, possibly checksummed, “attach-request” message using this AMAC and the proper attach stream numbers 620 , the PEA 120 waits for the Hub 110 to successfully read the attach-interest and then the attach-request messages. Reading of a valid attach-interest message by the Hub 110 causes the Hub 110 believe that there is a PEA 120 ready to send the longer (and hence more likely corrupted) attach-request.
[0081] Once a valid attach-interest is received, the Hub 110 schedules frequent receipt of the attach-request until it determines the contents of the attach-request, either by receiving the block intact with a valid checksum or by reconstructing the sent attach-request from two or more received instances of the sent attach-request. The Hub 110 then assigns a MAC address to the PEA 120 , sending the address to the PEA 120 using its AMAC address.
[0082] The Hub 110 confirms receipt of the MAC address by scheduling the reading of a small, possibly forward error-corrected, attach-confirmation from the PEA 120 at its new MAC address 610 . The Hub 110 follows this by sending a small, possibly forward error-corrected, confirmation to the PEA 120 at its MAC address so that the PEA 120 knows it is attached. The PEA 120 returns a final small, possibly forward error-corrected, confirmation acknowledgement to the Hub 110 so that the Hub 110 , which is in control of all scheduled activity, has full knowledge of the state of the PEA 120 . This MAC address remains assigned to that PEA 120 for the duration of the time that the PEA 120 is attached.
[0083] FIGS. 11 and 12 are flowcharts of Hub and PEA attachment processing, respectively, consistent with the present invention. When the Hub 110 establishes the network, its logic initializes the attachment process and, as long as the Hub 110 continues to function, periodically performs attachment processing. The Hub 110 periodically broadcasts heartbeats containing a Hub identifier (selecting a new heartbeat identifier value each time it reboots) and an indicator of the range of AMACs that can be selected from for the following attach opportunity [step 1110 ] ( FIG. 11 ). The Hub 110 schedules an attach-interest via a token that schedules a small PEA-to-Hub transmission for each of the designated AMACs, so unattached PEAs may request attachment.
[0084] Each attaching PEA 120 selects a new AMAC at random from the indicated range when it hears the heartbeat. Because the Hub 110 may receive a garbled transmission whenever more than one PEA 120 transmits, the Hub 110 occasionally indicates a large AMAC range (especially after rebooting) so that at least one of a number of PEAs 120 may select a unique AMAC 610 and become attached. When no PEAs 120 have attached for some period of time, however, the Hub 110 may select a small range of AMACs 610 to reduce attachment overhead, assuming that PEAs 120 will arrive in its vicinity in at most small groups. The Hub 110 then listens for a valid attach-interest from an unattached PEA [step 1120 ]. The attach-interest is a PEA-to-Hub message having the AMAC address 610 selected by the unattached PEA 120 .
[0085] Upon receiving a valid attach interest, the Hub 110 schedules a PEA-to-Hub attach-request token with the PEA's AMAC 610 and reads the PEA's attach-request [step 1130 ]. Due to the low-power wireless environment of the PAN 100 , the attach-request transmission may take more than one attempt and hence may require scheduling the PEA-to-Hub attach-request token more than once. When the Hub 110 successfully receives the attach-request from the PEA, it assigns a MAC address to the PEA [step 1140 ]. In some cases, the Hub 110 chooses the MAC address from the set of AMAC addresses.
[0086] The Hub 110 sends the new MAC address 610 in an attach-assignment message to the now-identified PEA 120 , still using the PEA's AMAC address 610 and a stream number 620 reserved for this purpose. The Hub 110 schedules and listens for an attach-confirmation response from the PEA 120 using the newly assigned MAC address 610 [step 1150 ].
[0087] Upon receiving the confirmation from the PEA 120 , the Hub 110 sends its own confirmation, acknowledging that the PEA 120 has switched to its new MAC, to the PEA 120 and waits for a final acknowledgment from the PEA 120 [step 1160 ]. The Hub 110 continues to send the confirmation until it receives the acknowledgment from the PEA 120 or until it times out. In each of the steps above, the Hub 110 counts the number of attempts it makes to send or receive, and aborts the attachment effort if a predefined maximum number of attempts is exceeded. Upon receiving the final acknowledgment, the Hub 110 stops sending its attach confirmation, informs its NI 430 ( FIG. 4 ) that the PEA 120 is attached, and begins exchanging both data and keep-alive messages (described below) with the PEA 120 .
[0088] When an unattached PEA 120 enters the network, its LLC 420 ( FIG. 4 ) instructs its LLT 440 to initialize attachment. Unlike the Hub 110 , the PEA 120 waits to be polled. The PEA 120 instructs its DCL 460 to activate and associate the heartbeat stream 770 ( FIG. 7B ) with the Hub's MAC address and waits for the heartbeat broadcast from the Hub 110 [step 1210 ] ( FIG. 12 ). The PEA 120 then selects a random AMAC address from the range indicated in the heartbeat to identify itself to the Hub 110 [step 1220 ]. The PEA 120 instructs its DCL 460 to send an attach-interest and an attach-request data block to the Hub 110 , and activate and associate the streams with its AMAC address [step 1230 ]. The PEA 120 tells its driver to activate and respond to the selected AMAC address for the attach-assignment stream.
[0089] The unattached PEA 120 then waits for an attach-assignment with an assigned MAC address from the Hub 110 [step 1240 ]. Upon receiving the attach-assignment, the PEA 120 finds its Hub-assigned MAC address and tells its driver to use this MAC address to send an attach-confirmation to the Hub 110 to acknowledge receipt of its new MAC address [step 1250 ], activate all attached-PEA streams for its new MAC address, and deactivate the streams associated with its AMAC address.
[0090] The PEA 120 waits for an attach confirmation from the Hub 110 using the new MAC address [step 1260 ] and, upon receiving it, sends a final acknowledgment to the Hub 110 [step 1270 ]. The PEA 120 then tells its NI 430 that it is attached.
[0091] The PEA 120 , if it hears another heartbeat from the Hub 110 before it completes attachment, discards any prior communication and begins its attachment processing over again with a new AMAC.
Exemplary Detachment and Reattachment Processing
[0092] The Hub 110 periodically informs all attached PEAs 120 that they are attached by sending them ‘keep-alive’ messages. The Hub 110 may send the messages at least as often as it transmits heartbeats. The Hub 110 may send individual small, possibly forward error-corrected, keep-alive messages to each attached PEA 120 when few PEAs 120 are attached, or may send larger, possibly forward error-corrected, keep-alive messages to groups of PEAs 120 .
[0093] Whenever the Hub 110 schedules tokens for PEA-to-Hub communications, it sets a counter to zero. The counter resets to zero each time the Hub 110 successfully receives a block (either uncorrupted or reconstructed) from the PEA 120 , and increments for unreadable blocks. If the counter exceeds a predefined threshold, the Hub 110 automatically detaches the PEA 120 without any negotiation with the PEA 120 . After this happens, the Hub 110 no longer schedules data or status transfers to or from the PEA 120 , and no longer sends it any keep-alive messages.
[0094] FIG. 13 is a flowchart of PEA detachment and reattachment processing consistent with the present invention. Each attached PEA 120 listens for Hub heartbeat and keep-alive messages [step 1310 ]. When the PEA 120 first attaches, and after receiving each keep-alive message, it resets its heartbeat counter to zero [step 1320 ]. Each time the PEA 120 hears a heartbeat, it increments the heartbeat counter [step 1330 ]. If the heartbeat counter exceeds a predefined threshold, the PEA 120 automatically assumes that the Hub 110 has detached it from the network 100 [step 1340 ]. After this happens, the PEA 120 attempts to reattach to the Hub 110 [step 1350 ], using attachment processing similar to that described with respect to FIGS. 11 and 12 .
[0095] If the Hub 110 had not actually detached the PEA 120 , then the attempt to reattach causes the Hub 110 to detach the PEA 120 so that the attempt to reattach can succeed. When the PEA 120 is out of range of the Hub 110 , it may not hear from the Hub 110 and, therefore, does not change state or increment its heartbeat counter. The PEA 120 has no way to determine whether the Hub 110 has detached it or how long the Hub 110 might wait before detaching it. When the PEA 120 comes back into range of the Hub 110 and hears the Hub heartbeat (and keep-alive if sent), the PEA 120 then determines whether it is attached and attempts to reattach if necessary.
CONCLUSION
[0096] Systems and methods consistent with the present invention provide a wireless personal area network that permit a host device to communicate with a varying number of peripheral devices with minimal power and minimal interference from neighboring networks by using a customized TDMA protocol. The host device uses tokens to facilitate the transmission of data blocks through the network.
[0097] The foregoing description of exemplary embodiments of the present invention provides illustration and description, but is not intended to be exhaustive or to limit the invention to the precise form disclosed. Modifications and variations are possible in light of the above teachings or may be acquired from practice of the invention. The scope of the invention is defined by the claims and their equivalents. | A device comprises circuitry and a transceiver. In operation, the device is configured to cause the transceiver to: receive a first message from another device to support at least one aspect of attachment of the device and the another device, send, to the another device, a second message after the first message and prior to attachment, receive, from the another device, a third message that is sent after the second message and prior to attachment, send, to the another device, a fourth message after the third message and prior to attachment, receive, from the another device, a fifth message that is sent after the fourth message and prior to attachment, and send, directly to the another device, data utilizing at least one channel for data transfer utilizing a second one of the addresses for identification in association with the device on the shared wireless communication medium. | 8 |
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of co-pending application Ser. No. 13/390,819, which is the U.S. national stage of International patent application no. PCT/JP2011/001038, filed Feb. 23, 2011 designating the United States of America. Priority is claimed based on Japanese patent application no. 2010-037474 filed Feb. 23, 2010 and Japanese patent application no. 2011-035531 filed Feb. 22, 2011, the entire disclosures of which are herein expressly incorporated by reference.
TECHNICAL FIELD
[0002] The present invention relates to a roller bearing, such as a tapered roller bearing, for supporting a rotating shaft of an automobile drive system (differential, transmission, and transfer), and a method for manufacturing the same.
BACKGROUND ART
[0003] The tapered roller bearing used in the automobile differential requires lowered torque particularly in low-velocity areas. Formation of an oil film on the entire roller surface is effective in order to reduce the torque of the tapered roller bearing.
[0004] Formation of an oil film, which covers a surface of either an end of a roller or a rib including a guide face for it and is disposed therebetween, is disclosed in Patent Documents 1 to 3. In Patent Document 1, minute recesses are formed on the roller guide face of the rib through shot blasting. Patent Document 2 discloses making a smooth surface into a finished surface in which troughs are randomly formed through machining using a grindstone attached with grains of different sizes.
[0005] Patent Document 3 discloses making a predetermined smooth surface have interspersed troughs of a predetermined depth with a stipulated surface roughness. A method of repeating, after every short period, bringing a disc-like grindstone into contact with a surface to be polished and then retreating therefrom is disclosed.
[0006] Patent Documents 4 to 6 disclose random provision of multiple minute recesses in any one of a rolling surface of the roller, an end of the roller, and a bearing ring raceway surface, and stipulation of the surface roughness thereof within a specific range so as to achieve excellent oil film formative action. They also disclose that these recesses may be machined through barreling or a method using shot blasting or the like.
[0007] Patent Document 7 discloses projection of approximately spherical particles made of 99% or greater purity silica onto a sliding surface of an aluminum alloy slide member so as to form a transcriptional layer in which the silica has been transcribed onto the sliding surface. In this method, the roughness of the sliding surface is finished to approximately Ra 0.3 μm through grinding before projecting the silica particles.
[0008] Patent Document 8 discloses projection of abrasive particles including #2000 or larger grains made from an elastic material, such as rubber, or thermoplastic elastomer, onto an object to be polished at an angle of 90 degrees or less as a method of finished polishing a surface of the object. As a result, the remaining grains sticking out from the object are removed through grinding, and the grinding grains and strips are also sufficiently removed at the same time, thereby achieving a clean surface with a good roughness. Finished grinding of a rolling surface of the roller by this method allows improvement in burn-on lifetime of the roller bearing and the like.
[0009] On the other hand, Patent Document 9 discloses a structure illustrated in FIG. 4 as an automobile transfer according to conventional technology. This transfer has a bevel pinion shaft 5 , a ring gear 6 , and a differential 7 disposed in a casing (gear box) 100 . The bevel pinion shaft 5 is supported by the casing 100 via two tapered roller bearings 10 A at a distance therebetween. These tapered roller bearings 10 A are applied with a pre-load in an axial direction from a screw thread-attached member 110 .
[0010] The differential 7 is configured by a differential casing 71 , pinion gears (differential gears) 73 fixed on either end of a pinion shaft 72 , and side gears (output gears) 74 for engaging with the respective pinion gears 73 . Front edges of axel shafts 8 are coupled with the respective side gears 74 .
[0011] A bevel pinion gear 51 on the front edge of the bevel pinion shaft 5 engages with the ring gear 6 . The ring gear 6 is fixed to a flange 71 a of the differential casing 71 . Cylinders 71 b on both ends of the differential casings 71 are supported by the casing 100 via tapered roller bearings 10 B. Rotation of the bevel pinion shaft 5 drives the differential 7 via the bevel pinion gear 51 and the ring gear 6 .
[0012] The transfer has a problem that friction occurs between ends of the tapered rollers and the inner ring rim, which constitute the tapered roller bearings 10 A, thereby generating sliding friction. In order to resolve this problem, Patent Document 9 discloses that the bevel pinion shaft 5 is supported by double row angular ball bearings having a specific shape instead of the tapered roller bearings 10 A.
PRIOR ART DOCUMENTS
[0013] Patent Documents
Patent Document 1: JP Hei 6-241235 A Patent Document 2: JP Hei 7-42746 A Patent Document 3: JP 2003-269468 A Patent Document 4: JP 2006-9962 A Patent Document 5: JP 2006-9963 A Patent Document 6: JP 2006-9964 A Patent Document 7: JP 2009-526126 A Patent Document 8: JP 2009-113189 A Patent Document 9: JP 4058241 B
SUMMARY OF THE INVENTION
Problem To Be Solved By the Invention
[0023] The methods of Patent Documents 1 to 8 have room for improvement in torque reduction of the tapered roller bearing for supporting the rotating shaft of the automobile drive system (differential, transmission, and transfer). Note that the automobile transfer of Patent Document 9 deals with the above through use of double row angular ball bearings having a specific shape instead of the tapered roller bearings.
[0024] An objective of the present invention is to reduce torque of a roller bearing such as a tapered roller bearing for supporting a rotating shaft of an automobile drive system.
Solution to the Problem
[0025] In order to resolve the above problem, a roller bearing according to a first aspect of the present invention includes an inner ring having an inner ring raceway surface, an outer ring having an outer ring raceway surface, and a roller deployed in a freely rolling manner between the raceway surfaces. A number of recesses having circular openings with diameters of 10 μm to 50 μm inclusive are formed at intervals of 10 μm to 200 μm inclusive on at least a target surface which is at least any one of the inner ring raceway surface, the outer ring raceway surface, a roller surface of the roller, an end of the roller, and a rib surface in contact with the end of the roller.
[0026] It is preferable for the target surface to have arithmetic average roughness (Ra) of a roughness curve indicating surface roughness of 0.1 to 0.2 μm, skewness (Rsk) of −1.0 to −0.2, and kurtosis (Rku) of 3 to 7.
[0027] The roller bearing of the first aspect may have a surface layer at a depth of 10 μm or less from the surface of the target surface that is harder than a core at a depth of more than 10 μm from the surface.
[0028] In the roller bearing of the first aspect, the roller may be a tapered roller used for application of supporting a rotating shaft of an automobile differential, transmission, or transfer (tapered roller bearing for an automobile drive system).
[0029] A roller bearing manufacturing method according to a second aspect of the present invention carries out a shot blast step of projecting spherical particles (e.g., silica particles, alumina particles, or steel particles) having a Mohs hardness of 6 or greater and diameters of 10 μm to 100 μm inclusive so as to form recesses and protrusions, as a surface treatment step for a to-be-treated surface including at least any one of an inner ring raceway surface, an outer ring raceway surface, a roller surface of the roller, an end of a roller, and a rib surface in contact with the end of the roller of a roller bearing that includes an inner ring having the inner ring raceway surface, an outer ring having the outer ring raceway surface, and the roller deployed in a freely rolling manner between the raceway surfaces.
[0030] Through the shot blast step above, the to-be-treated surface may be made to have a number of recesses, which have circular openings with diameters of 10 μm to 50 μm inclusive, at intervals of 10 μm to 200 μm inclusive, and a state fulfilling arithmetic average roughness (Ra) of 0.1 to 0.2 μm, skewness (Rsk) of −1.0 to −0.2, and kurtosis (Rku) of 3 to 7.
[0031] The shot blast step is preferably carried out using spherical silica microparticles of 99% or greater purity as the spherical particles.
[0032] A protrusion removal step for removing protrusions generated in the shot blast step is preferably carried out as the surface treatment step after the shot blast step.
[0033] The protrusion removal step may be carried out by bombarding abrasive particles formed of elastic bodies and grains on a to-be-treated surface after the shot blast step.
[0034] Since the recesses have circular openings, they act as better oil pools than recesses having linear or elliptic openings. Recesses with linear or elliptic openings have portions with small touch areas, which make it easier to eliminate oil therefrom. Since moderate oil pools are formed if the diameters of the circular openings of the recesses are 10 μm to 50 μm inclusive, and the set intervals are 10 μm to 200 μm inclusive, the surface in which the recesses are formed has excellent oil film formation capability.
[0035] The target surface (surface in which the recesses are formed) is 0.1 to 0.2 μm in arithmetic average roughness (Ra) of a roughness curve indicating surface roughness, −1.0 to −0.2 in skewness (Rsk), and 3 to 7 in kurtosis (Rku), and thereby has excellent oil film formation capability since it is a more favorable plateau surface having coexisting flat portion and recesses (oil pools) than when the above conditions are not satisfied.
[0036] As a result, in the case of using the tapered roller bearing of the first aspect for application of supporting a rotating shaft of an automobile drive system, sliding friction is reduced and torque is low even at the time of driving in low-velocity areas.
[0037] It is preferable that the surface in which the recesses are formed has an area rate of openings of the recesses of 5 to 20%. It is also preferable that the surface in which the recesses are formed has recess summated diameters of 5 to 50% along an extended line of a diameter of the openings of the recesses. If the area rate of the recesses exceeds 20%, the surface (smooth surface) excluding the recesses may not be able to support a load and an oil film may not be formed well. If the summated diameter ratio of the recesses exceeds 50%, pressure on the rims of the recesses decreases and the formation of an oil film becomes difficult.
[0038] If depth of the recesses is less than 1 μm, there is a high risk that the recesses will be eliminated through initial abrasion, and if the depth exceeds 5 μm, such a depth reduces the capability of moving the oil accumulated in the recesses to the smooth surface and forming an oil film. Accordingly, it is preferable that depth of the recesses is no less than 1 μm at the shallowest portion, and no greater than 5 μm at the deepest portion.
[0039] The recesses of the above structure may be formed by a method including the shot blast step of forming recesses and protrusions by projecting glass beads on a recess formation surface (to-be-treated surface), and a protrusion removal step of removing the protrusions (portions protruding out from the pre-treated surface) formed in the shot blast step.
[0040] While the protrusion removal step may be carried out through grinding, it is preferably carried out by bombarding abrasive particles formed of elastic bodies and grains on the to-be-treated surface after the shot blast step.
[0041] Adoption of the shot blast step of projecting glass beads and the protrusion removal step of bombarding the abrasive particles allows easy formation of recesses, which have circular openings and controlled size, depth, and intervals, even when the to-be-treated surface is large or form of the to-be-treated surface is complicated.
[0042] The shot blast step may be carried out using as the glass beads, spherical silica microparticles of 99% or greater purity having diameters between 10 μm and 100 μm inclusive and a Mohs hardness of 6 or greater.
[0043] In the case of an inner ring, an outer ring, and a tapered roller to which a typical heat treatment has been conducted for a material made of high carbon chromium bearing steel (SUJ2), once the silica particles are projected at a pressure of 1470 kPa or less for 20 minutes or less, the recesses of the aforementioned structure may be formed through the protrusion removal step of bombarding the abrasive particles. Moreover, in this case, surface roughness of the to-be-treated surface before the protrusion removal step may be made to have an arithmetic average roughness (Ra) of approximately 0.1 μm. The ten points height roughness(Rz) may be made between 0.4 to 2.0 μm in the protrusion removal step.
[0044] Note that if the protrusion removal step is carried out by bombarding the abrasive particles, height of the smooth surface (surface excluding recesses) after treatment may tend to be uneven, while if the protrusion removal step is carried out by barreling, height of the smooth surface after treatment may be made even. As a result, since an oil film having a uniform thickness is formed on the recess-formed surface without contact pressure increasing locally, carrying out the protrusion removal step by barreling achieves a greater torque reduction effect than by bombarding the abrasive particles.
Advantageous Effect of the Invention
[0045] According to the roller bearing of the present invention, formation of specified recesses on a roller surface or a surface in contact with a roller reduces torque due to excellent capability of forming an oil film on the roller surface.
[0046] More specifically, since a tapered roller bearing for supporting a pinion shaft constituting the automobile differential has great loss due to torque, excellent fuel consumption improvement is achieved by reducing the torque through application of the present invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0047] FIG. 1 is a cross-sectional view illustrative of a tapered roller bearing according to an embodiment of the present invention;
[0048] FIG. 2 is a cross-sectional view illustrative of a vertical inner ring rotary testing machine used in this embodiment;
[0049] FIG. 3 is a diagram illustrative of a jig usable for projecting silica particles and abrasive particles only on a large-diameter end of the tapered roller bearing;
[0050] FIG. 4 is a cross-sectional view illustrative of the automobile transfer according to the conventional technology disclosed in Patent Document 9; and
[0051] FIG. 5 shows graphs illustrative of change in hardness along the depth from the surface measured in a second embodiment, where FIG. 5A gives results of sample No. 6, and FIG. 5B gives results of sample No. 7.
DESCRIPTION OF EMBODIMENTS
[0052] Hereinafter, embodiments of the present invention will be described.
First Embodiment
[0053] A tapered roller bearing 10 of FIG. 1 is constituted by: an inner ring 1 having an inner ring raceway surface 1 a; an outer ring 2 having an outer ring raceway surface 2 a; multiple tapered rollers 3 deployed in a freely rolling manner between the raceway surfaces 1 a and 2 a; and a cage 4 . Rib surfaces 11 a and 12 a making contact with ends of the tapered rollers 3 are formed on the inner ring 1 by providing ribs 11 and 12 on either axial end.
[0054] A test tapered roller bearing, bearing model number HTFR45-24 (inner ring: 45 mm, outer ring: 95.25 mm, maximum width: 35 mm, tapered roller diameter: 13.779 mm), is manufactured as the tapered roller bearing 10 having the configuration of FIG. 1 .
[0055] The inner ring 1 , the outer ring 2 , and the tapered roller 3 are manufactured in the following manner. A material made of SUJ2 is machined into respective forms and carbonitrided for three hours in a mixed gas atmosphere (Rx gas, enriched gas, and ammonia gas) at 840 degrees Celcius. Oil hardening and annealing are then carried out. This made respective surface layers (portion until depth of 250 μm from the surface) of the inner ring 1 , the outer ring 2 , and the tapered roller 3 have residual austenite within a range of 15 to 40 volume %, and hardness within a range of 62 to 67 HRC (746 to 900 Hv).
[0056] A shot blast step of projecting glass beads onto the tapered roller 3 is then carried out using the following method. A shot blast device for placing a product in a basket container and projecting glass beads from a nozzle into the container while rotating the container is used. The opening of the container is opened wide and a projection nozzle tip is arranged in this entrance.
[0057] The glass beads are silica (SiO 2 ) particles of 99% or greater purity having an average diameter of 40 μm and a Mohs hardness of 6 or greater, manufactured into a spherical shape by fusion method. Fusion is a method of heating a heat-resistant container containing raw powder using a burner of approximately 2500 degrees Celcius so as to heat the raw powder in the container to 1100 degrees Celcius and fuse it into a spherical shape.
[0058] Conditions for the shot blast step are that container rotation speed is 5 rpm, projection is performed at a speed such that projection pressure on the tapered roller 3 is 600 kPa, and projection time is ten minutes.
[0059] A protrusion removal step for the tapered roller 3 is then carried out using the following method. Particles resulting from diamond grains with an average diameter of 10 μm adhering onto surfaces of 1 mm-diameter rubber (acrylonitrile-butadiene rubber) particles are prepared as abrasive particles. Diamond grain content of the abrasive particles is 5 mass %.
[0060] The abrasive particles are bombarded at an angle (10 to 60 degrees) against respective sides of the tapered roller 3 using an air blast device after the shot blast step. Air blast conditions are an air pressure of 0.4 MPa and a distance between the nozzle and the work area of 150 mm. Processing time is varied from 3 to 12 minutes for each sample.
[0061] For samples Nos. 1 to 4, the shot blast step and the protrusion removal step are carried out using the aforementioned methods, surface condition of a tapered roller 3 is determined, and ten points height roughness (Rz), size of recess opening, and intervals between recesses are then found.
[0062] A tapered roller 3 (sample No. 5) for which a barreling step is carried out but the shot blast step and the protrusion removal step are not, and a tapered roller 3 (sample No. 6) for which any of the barreling step, the shot blast step and the protrusion removal step are not carried out are also prepared, and ten points height roughness (Rz), size of recess opening, and intervals between recesses are found. Note that the barreling step for sample No. 5 is carried out under normal conditions.
[0063] Tapered roller bearings Nos. 1 to 6 are assembled using the inner ring 1 , the outer ring 2 , the respective tapered rollers 3 Nos. 1 to 6 obtained in the above manner, and the cage 4 manufactured by SPCC, and a rotation test is then conducted using an apparatus shown in FIG. 2 .
[0064] The apparatus of FIG. 2 is a vertical inner ring rotary testing machine constituted by a main shaft 21 , a supporting bearing 22 , a main body 23 , and a hydrostatic bearing 24 . The supporting bearing 22 is provided on an axial end 21 a of the main shaft 21 . The hydrostatic bearing 24 is provided on an axial end of the main body 23 . The testing machine is used by fitting the inner ring 1 of a tapered roller bearing 10 or test bearing on the outside of the main shaft 21 , and fitting the outer ring 2 on the inside of the main body 23 .
[0065] An axial load Fa may be applied from above the hydrostatic bearing 24 . A load cell 26 is connected to a side of the main body 23 via a bar 25 . Dynamic friction torque applied to the main body 23 may be detected by this load cell 26 . A passage 27 for supplying a lubricant J to the test bearing 10 is formed in the main body 23 . The passage 27 opens at a side of the main body 23 . A thermocouple 28 for measuring the temperature of the test bearing 10 is also provided.
[0066] The test bearing is attached to this apparatus, and while supplying mineral oil (VG68) at a temperature of 60 degrees Celcius±3 degrees Celcius, 200 ml/min, which is less than normal supplied quantity (300 ml/min), torque after the inner ring 1 is rotated for 24 hours under conditions of 4 kN of Fa and a rotation speed of 300 min-1 is measured. A torque ratio where torque of the tapered roller bearing No. 6 is ‘1’ is calculated based on measured torque values of the tapered roller bearings Nos. 1 to 5.
[0067] Results thereof are given in the following Table 1. Maximum recess depth in Table 1 is measured value of the ten points height roughness (Rz).
[0000]
TABLE 1
Roller surface
Maximum
Torque ratio of
No.
Mechanical surface treatment
recess depth
roller bearing
1
3 min. abrasive particle
1.5 μm
0.8
projection after silica particle
projection
2
6 min. abrasive particle
1.0 μm
0.5
projection after silica particle
projection
3
9 min. abrasive particle
0.5 μm
0.6
projection after silica particle
projection
4
12 min. abrasive particle
0.2 μm
0.7
projection after silica particle
projection
5
Barreling
0.5 μm
0.8
6
None
0.08 μm
1
[0068] The tapered rollers Nos. 1 to 4 have different maximum recess depths due to different projection times of the abrasive particles after the projection of the silica particles. The tapered roller bearing using the tapered roller No. 2 having a maximum recess depth of 1.0 μm has the smallest torque, which is half of that of No. 6. The recesses formed in the surfaces of the tapered rollers Nos. 1 to 4 have circular openings, where diameters of the openings are 10 to 50 μm. Intervals between the recesses are 10 to 200 μm.
[0069] While maximum recess depth of the tapered rollers No. 3 and No. 5 is the same, No. 3 to which abrasive particles are projected after the silica particles are projected has a smaller torque ratio than No. 5 to which barreling is carried out. The recesses formed in the surface of the barreled, tapered roller have linear openings rather than circular ones.
[0070] Moreover, the tapered rollers Nos. 1 to 4 are 0.1 to 0.2 μm in arithmetic average roughness (Ra) of a roughness curve indicating surface roughness, −1.0 to −0.2 in skewness (Rsk), and 3 to 7 in kurtosis (Rku).
[0071] Note that according to this embodiment, while minute recesses whose openings are circular are provided due to projecting abrasive particles only on the surfaces of the tapered rollers 3 of the tapered roller bearings after silica particles are projected, the recesses may be provided in all or a part of the tapered rollers 3 , the inner ring raceway surface 1 a, the outer ring raceway surface 2 a, and the rib surfaces 11 a and 12 a. Moreover, the present invention achieves the same results even with roller bearings other than the tapered roller bearings.
[0072] Furthermore, in the case of projecting silica particles and abrasive particles only on the large diameter end of the tapered roller 3 , the tapered roller 3 may be attached next to a disc-like jig 9 so as to project the particles while rotating the jig 9 , as shown in FIG. 3 . Particularly, since a large sliding friction generates on the large diameter end of the tapered roller when the tapered roller bearing (for example, the tapered roller bearing 10 A of FIG. 4 ) is supported by a differential pinion shaft, torque may be sufficiently reduced even when the aforementioned recesses are provided only on that end.
Second Embodiment
[0073] Sample No. 7, which is the tapered roller 3 of the tapered roller bearing 10 of FIG. 1 , where processing up through the shot blast step is carried out using the same method as with samples Nos. 1 to 4, and the protrusion removal step is not carried out, is prepared.
[0074] Sample No. 8, which is the tapered roller 3 of the tapered roller bearing 10 of FIG. 1 , where processing up through the shot blast step is carried out using the same method as with samples Nos. 1 to 4 except that alumina particles are used instead of the silica particles, and the protrusion removal step is not carried out, is prepared. Alumina (Al 2 O 3 ) particles of 99% or greater purity having an average diameter of 40 μm and a Mohs hardness of 6 or greater, manufactured into a spherical shape through fusion are used.
[0075] Surface conditions of the tapered rollers 3 of samples No. 7 and No. 8 are measured, and arithmetic average roughness (Ra) of a roughness curve indicating surface roughness, skewness (Rsk), kurtosis (Rku), ten points height roughness (Rz), size of recess openings, and recess intervals are found. Change in hardness along the depth from the surface of the ends of the tapered rollers 3 of samples No. 6 (sample for which the shot blast step is not carried out) and No. 7 is also found.
[0076] Tapered roller bearings Nos. 7 and 8 are assembled using the inner ring 1 , the outer ring 2 , the respective tapered rollers 3 of samples Nos. 7 and 8, and the cage 4 manufactured by SPCC, and the same rotation test as in the first embodiment is then conducted using the apparatus shown in FIG. 2 so as to measure torque. A torque ratio where torque of the tapered roller bearing No. 6 is ‘1’ is calculated based on measured torque values of the tapered roller bearings of samples Nos. 7 and 8.
[0077] Results thereof are given in the following Table 2 and FIG. 5 . FIG. 5 shows graphs illustrative of change in hardness along the depth from the surface, where FIG. 5A gives results of sample No. 6, and FIG. 5B gives results of sample No. 7.
[0000]
TABLE 2
Roller surface condition
Torque ratio of
No.
Ra
Rsk
Rku
Rz
roller bearing
7
0.1
−0.2
3
1.8
0.75
8
0.2
−1
7
2.1
0.50
[0078] The recesses formed in the surfaces of the tapered rollers Nos. 7 and 8 have circular openings, where diameters of the openings are 10 to 50 μm. Intervals between the recesses are 10 to 200 μm.
[0079] It is understood from these results that even when the protrusion removal step is not carried out, surfaces of the tapered rollers may have multiple recesses, which have circular openings with diameters of 10 μm to 50 μm inclusive, at intervals of 10 μm to 200 μm inclusive, and a state fulfilling arithmetic average roughness (Ra) of 0.1 to 0.2 μm, skewness (Rsk) of −1.0 to −0.2, and kurtosis (Rku) of 3 to 7, thereby sufficiently reducing the torque.
[0080] Moreover, as is understood through comparison of FIGS. 5A and 5B , a surface layer at a depth of 10 μm or less from the surface may be made harder than a core at a depth of more than 10 μm from the surface through shot blasting using spherical particles having a Mohs hardness of 6 or greater.
REFERENCE SIGNS LIST
[0000]
1 : inner ring
1 a: inner ring raceway surface
11 , 12 : rib
11 a, 12 a: rib surface
2 : outer ring
2 a: outer ring raceway surface
3 : tapered roller
4 : cage
5 : bevel pinion shaft
6 : ring gear
7 : differential
71 : differential casing
71 a: flange
71 b: cylinder
72 : pinion shaft
73 : pinion gear (differential gear)
74 : side gear (output gear)
8 : axel shaft
9 : jig
10 : tapered roller bearing
10 A: tapered roller bearing
10 B: tapered roller bearing
100 : casing (gear box)
110 : screw thread-attached member | Spherical particles having diameters of 100 μm or less are projected on a surface of a tapered roller so as to form recesses and protrusions, and abrasive particles are then projected thereon so as to remove the protrusions. The abrasive particles result from adhering 5 mass % diamond grains with an average diameter of 10 μm on surfaces of 1 mm-diameter rubber particles. As a result, multiple recesses having circular openings of 50 μm or less are formed on the surface of the tapered roller at intervals of 200 μm or less. These recesses become moderate oil pools, heightening the oil film formation capability of the roller surface, and thus torque of the tapered roller bearing may be decreased. | 8 |
FIELD OF THE INVENTION
[0001] This invention relates to acoustic feedback in a communications device and specifically to speakerphone station sets and particularly to reduction of singing caused by feedback of a speaker output to the station set microphone. It also relates, in general, to any system in which audio output of a speaker may feed back into a microphone of the system causing singing (positive feedback) to occur. It specifically concerns a method and apparatus for determining the level of acoustic energy due to the output of a speaker appearing at a microphone of the communication device and to identifying such feedback energy as differentiated from that of the spoken input to the microphone.
BACKGROUND OF THE INVENTION
[0002] The amount of acoustic energy output of a speaker being fed back into a microphone of a duplex acoustic system with gain (i.e., a device used for communication purposes) determines the system acoustic stability. Such stability is important to prevent the generation of “singing” in which feedback of the speaker output onto the microphone causes reinforcement of sound from the loudspeaker and thus causes the speaker to emit a howl or similar high-pitched noise.
[0003] There are existing methods of preventing this singing effect that operate by inserting switched loss into either the speaker or microphone path to ensure system stability. The amount of switched loss to insert is determined by comparing the microphone signal level to the speaker signal level from the network via a hybrid connected to the speakerphone. Examination of the relative levels of the two signals permits a determination as to which signal level is presently active (i.e. speaker output or voice input). Loss is inserted in the path which is determined to be presently inactive ensuring that the total loop electro-acoustic gain of the speakerphone and the network is less than one at the frequency where at zero degrees loop phase shift is experienced. This criterion, known as the Nyquist stability criterion, determines how much loss must be present in the electro-acoustic loop consisting of the speakerphone and the network to sustain oscillations, in order to ensure stability. The overall loss inserted, in many arrangements, to maintain stability is related to the sum of signal-dependent switched loss and some fixed loss amount, which is needed to provide “sing” margin to compensate for inaccuracies in determination of the total amount of loop gain necessary to prevent oscillations at specific frequencies.
[0004] The difficulty of these implementations has been in determining the amount of coupling which exists between the speakerphone's speaker and its microphone (i.e., speaker output vs. voice input). The acoustic environment between speaker and microphone is often unstable making a determination between speaker feedback and voice input to the microphone difficult to assess. In another arrangement, it has been thought possible to have the relative signal levels determined at the hybrid connection of the speakerphone to the telephone network. It is theoretically possible to sample incoming and outgoing speech at the hybrid connecting the phone to the network to infer loop gain, but this method has difficulties due to the isolation loss of the hybrid and is often unsatisfactory
SUMMARY OF THE INVENTION
[0005] In an exemplary embodiment of the invention, identification of signals (i.e., voice input or speaker output) in a process for reducing acoustic feedback, in a communication device, is accomplished by adding a signature noise (i.e., an identification mark) to output signals radiated by the speaker to enable these signals to be separated from speech input to the microphone. Having identified the signal (i.e., speech output) likely to cause a “singing” phenomenon, appropriate insertion loss to reduce the feedback may be added to the appropriate speech path within the communication device, to reduce a probability of singing.
[0006] In the exemplary embodiment of the invention, the signature noise, applied to the speech output, comprises a psuedo-noise signal consisting of a digitally generated sequence (i.e., a PN sequence). The envelope of the speech signal fed to the loudspeaker modulates this PN sequence.
[0007] The “signature” (i.e., PN sequence) added to speech issuing from the loud speaker identifies it in contrast to voice speech input to the microphone allowing it to be used to assist in any loss-switching process. In creating the signature, the speech output of the loudspeaker is combined with a pseudo-noise signal waveform consisting of a digitally generated sequence. The envelope of the speech that is fed to the loudspeaker modulates the PN signal. As such, it represents a low-level, “background” pink noise signal whose amplitude is proportional to the envelope of the speech that issues from the loudspeaker.
[0008] The speech input to the microphone is correlated with a version of the PN sequence, such that the correlated result is in direct proportion to the amount of speech sampled by the microphone issuing from the loudspeaker. Voice input to the microphone does not contain the PN sequence and its level may be separately ascertained. As part of the PN detection process the voice input speech is largely ignored so as to be independent from the PN correlation output. For wideband acoustic systems, the technique may be applied with pink noise “bands”, which utilize separate PN sequences. In such an embodiment, separate correlators may be used to adjust loss in various portions of the audio pass band to effect stability control, minimizing degradation of the entire program content due to feedback in only one portion of the pass band.
[0009] A second PN sequence may also be used to characterize the acoustic coupling path between the speaker and microphone. This second PN sequence would be made orthogonal to the first PN sequence in order to avoid interference between the two, and would be sent at a constant level through the loudspeaker. This second PN sequence would then be received by the microphone and correlated against the transmitted sequence to determine the impulse response of the acoustic path. This impulse response is then used to control an acoustic echo canceller. The advantage of using a PN sequence in addition to human speech in an acoustic echo canceller is that the PN sequence is a broadband signal and, hence, more accurately probes the acoustic environment.
BRIEF DESCRIPTION OF THE DRAWING
[0010] The sole FIGURE is a block schematic of a speakerphone suitable for practicing the principles of the invention.
DETAILED DESCRIPTION
[0011] A speakerphone 101 , as illustrated in the drawing, includes processing modules enabling practice of a method of identifying speaker output signals in accord with the principles of the invention. The illustrative speakerphone is attached to the network through a hybrid 103 . Hybrid circuits are well known in telephony and further discussion is not believed necessary. Input into and output from the speakerphone is by the loudspeaker 131 and microphone 133 , respectively. Incoming signals from the telephone network are transmitted from the hybrid 103 to an envelope detector 105 to convert the incoming signals to a slowly varying voltage level that follows the energy of the incoming signal. The output of the envelope detector 105 is applied to a gain cell 113 (multiplier) and coupled to the loudspeaker 131 via an audio amplifier 123 . Output signals are also routed to directly couple the hybrid 103 to another gain cell (multiplier) 115 that is also coupled to the amplifier 123 and loudspeaker 131 . Those skilled in the art will observe that the analog processing functions described illustratively above could be performed by digital signal processing means.
[0012] An exemplary embodiment contemplates a speakerphone wherein a loss-control processor is used to effect switched loss in either the transmit or receive path via the gain cells. This loss control processor is responsive to sensed envelopes of incoming (from the network) speech, as well as outgoing (to the network) speech, and the filtered correlator output.
[0013] In accord with the invention, a PN sequence generator 111 is connected to apply the PN sequence to the gain cell 113 where it is modulated by the envelope of the incoming speech. In one exemplary embodiment, a minimum (non-zero) amount of PN noise is applied even when incoming speech is not present. This level ensures that the system will be able to prevent buildup of feedback in situations where neither incoming nor outgoing speech is present. Since the PN noise is low-level, it will not seriously degrade the quality of the incoming speech as it issues from the loudspeaker nor will it pose objectionable “standby” noise.
[0014] Incoming voice-generated speech (i.e., human-generated input speech) is coupled from microphone 133 to amplifier 125 and coupled to gain cell (multiplier) 117 . An envelope detector 121 is coupled to detect the envelope of the amplified speech output of the microphone 133 . A gain cell (multiplier) 117 connects amplifier 125 to the hybrid circuit 103 , effecting a means of inserting loss into the transmit path to the network.
[0015] The output of amplifier 125 is also connected to a correlator circuit 119 . Correlator circuit 119 is also connected to receive the PN sequence from PN sequence generator 111 . The correlator 119 output identifies speaker output fed back to the microphone. The correlator output is filtered in filter 109 to band limit it to generate a signal reflective of the amount of feedback signal from the loudspeaker. This reflective signal is applied to a loss control processor 107 . Both envelope detectors 121 and 105 have outputs applied to loss control processor 107 whose function is to determine the amount of switched loss to be applied to reduce the speakerphone-network loop gain to less than one according to the Nyquist stability criterion.
[0016] The loss control processor 107 is responsive to envelope detector 105 and 121 representing input and output signals and to the filtered correlator output. Its (i.e., Correlator 119 ) function is to correlate the microphone signal output with a version of the PN sequence so that the output of the microphone, due to speech input, is differentiated from speech output. Hence, loss control is activated in direct proportion to the amount of speech sampled by the microphone that has issued from the loudspeaker. Voice input speech applied to the microphone will not contain the PN sequence. Accordingly, the speech input signal level may be accurately determined. In operation such as is contemplated in the exemplary embodiment, the human speech will be ignored by the correlator, because it contains no significant PN sequence content. The information representing the differential speech characteristics is coupled to the loss control processor 107 that determines the loss to be applied to the speech circuits. The loss control processor 107 may be a stored program control processor programmed in software to perform the specified function. No detailed structural description is believed necessary, since stored program processors have a standard structure.
[0017] Since the PN sequence spreads the frequency content of the noise over the audio pass band of the speaker, uneven frequency response of the loudspeaker or microphone, which partly determines the extent of loudspeaker-microphone coupling will pose less of an influence on the accuracy of the feedback determination than with conventional systems. It should be noted that movement of a speakerphone within an enclosed sound-field environment could cause violent changes in speaker/microphone coupling. The ability of the PN-pilot technique to detect these changes in real time can reduce the need to apply large “singing” safety margins that tend to make speakerphone conversations less “transparent”.
[0018] A feature of the described method is its ability to extend the process to characterize the acoustic channel for purposes of echo cancellation or equalizing the loudspeaker response to improve audio quality. In one arrangement a second PN sequence may be added for adjusting echo-canceling circuitry.
[0019] It is readily apparent that the foregoing technique may reduce the disruptive effects of a condition of “double talk”, where high speech levels are produced at the microphone from both incoming speech and feedback speech input. Such cases occur when the user of the speakerphone attempts to interrupt continuous speech arriving from the distant talker. In this instant, PN sequence levels are detected and appropriate supplemental loss may be is inserted into the loudspeaker path to ensure that the speakerphone user will be heard by the distant party as an “interrupt”.
[0020] While the exemplary embodiment has been presented in terms of a speakerphone, it is to be understood that any communications device combining speech input and speech output, may advantageously utilize the described invention. For example, a small handheld device could very easily experience acoustic feedback between an output speaker (i.e., not a loud speaker here) and an input microphone due to close proximity of the two and because a handheld speakerphone is subject to movement in a near-field environment which may contain reflective objects capable of materially changing speaker-microphone coupling at various frequencies. Other embodiments, permitting practice of the invention, will be readily apparent to those skilled in the art, for example suppression of public address system feedback. | In a speakerphone device identification of signals (i.e., voice input or speaker output) in a process for reducing acoustic feedback, in a communication device, is accomplished by adding a signature noise (i.e., an identification mark) to output signals radiated by the speaker to enable these signals to be separated from speech input to the microphone. Having identified the signal (i.e., speech output) likely to cause a “singing” phenomenon, appropriate insertion loss to reduce the feedback may be added to the appropriate speech path within the communication device, to reduce a probability of singing. | 7 |
BACKGROUND OF THE INVENTION
1. Field
The invention is in the field of foot support devices, for use when washing, drying, or pedicuring a foot, in or out, of shower stalls or bath tubs.
2. State of the Art
Proper foot elevation and support, to help maintain balance for a human while washing, drying, pedicuring the foot or shaving leg has not been overlooked. U.S. Pat. Nos. 1,265,609, 1,272,936, 2,576,883, 2,818,577, D287,075, 3,275,283, D340,508 and 4,489,448 are all examples of such prior art. Although these inventions may fit the purpose to which they address, they would not be as suitable for the purposes of the present invention as previously described.
SUMMARY OF THE PRESENT INVENTION
The present invention consists of a binary, or two-part, platform, and a two-part, single legged, elongate support member.
Accordingly, it is an object of the present invention to be modest in size.
Another object is to provide comfortable and sturdy accommodations, for the foot and applicable grooming needs, for the user of the present invention.
Another object is to allow the user of the present invention, convenient accessibility to his/her applicable grooming needs.
It is yet another object, to provide the user the option of adjusting the present invention for left or right-handed use.
It is yet another object of the present invention to allow for and adapt to, various height adjustments.
A BRIEF DESCRIPTION OF DRAWINGS
Other objects and features of the present invention will become apparent from the following description, taken together with the accompanying drawings, in which:
FIG. 1 is a perspective view of the present invention;
FIG. 2 is a transverse section of trays detached;
FIG. 3 is a longitudinal vertical section of the primary tray;
FIG. 4 is an aerial view of the platform, attached;
FIG. 5 is a perspective view, of the underside, of the primary tray.
DETAILED DESCRIPTION OF INVENTION
Referring now to the drawings, a device as shown in FIG. 1, constructed in accordance with the teachings of the present invention, is illustrated. The device FIG. 1 comprises a two-part platform 9, and a two-part, single legged, elongate support member 3. The two-part platform 9 consists of a primary tray 1, and a secondary tray 2. The structure and purpose of the primary tray 1, is to hold the foot of the user. One cavity 10, which intersects the length of primary tray 1, is the designated area for placement of the ball of the human foot. Perforations' 11 are present around the primary tray 1 perimeter, to allow residual water passage through the primary tray 1.
The secondary tray 2, of the two-part platform 9, possesses three receptacles 6,7,8 of different dimensions to hold applicable grooming needs. Although not exclusive, the preferred usage for the receptacles 6,7,8 is as follows. The first receptacle 6, is located nearest the heel of the foot of user, during use, and has one hole 15 in its center to hold a disposable razor. The second receptacle 7, has one hole 16 in its center and is located between the first 6 and third 8 receptacle. The purpose of the second receptacle 7, is to temporarily hold fresh water. The purpose of the third receptacle 8, which is located nearest the toes of the user while in use, is to hold shave gel, lotion, or soap,
The primary tray 1 has raised sides 12 and the secondary tray 2 has an open wedge 13 on each of its opposing sides. These side features 12,13 on the primary 1 and secondary tray 2, allow the user of the present invention, to detach and join the primary tray 1 and the secondary tray 2.
The primary 1 and the secondary tray 2, both contain one standard hook, not shown, in the rear. This standard hook, is positioned in the rear side of each tray 1,2, which will allow each tray 1,2, to be hung for drying and storage.
A pocket 14 is formed underneath the platform 9, by sides extending away from tray 1. The pocket 14 allows the support member 3 to securely affix to the tray 1. The support member 3 divides with a rod 4, being the upper top portion of the support 3, and a base 5, being the bottom portion of support 3. The rod 4 has a narrower circumference than the base 5, which allows the rod 4 to slide into and fit securely inside the base 5. The surface underneath the base 5, houses multiple rubber feet, not shown, being made like suction cups, these rubber feet will provide secure adherence of the present invention FIG. 1, to shower or bath tub floor surfaces. While in use, the present invention figure I maintains a horizontal orientation.
The rod 4 contains three spaced holes' 4x, which pierces through the rod 4, and are located along its extended lower half. The base 5 contains one hole 5x, which pierces through the base 5, and is located along its extended upper half. These holes' 4x, 5x allow two height adjustment methods, to be adapted by the present invention FIG. 1.
One height adjustment method, which may be adapted to holes 4x, 5x in the support member 3, is as follows. As the rod 4 is extended into the base, a standard peg, not shown, may be inserted in the hole 5x of the support member 3. The rod 4 and the base 5 will be mated up as the peg is inserted through to any hole 4x in the rod 4. This peg will allow the user of the present invention FIG. 1, to join the rod 4 and the base 5 parts together, at the desired height.
Another height adjustment method, which may be adapted to support member 3, is as follows. A standard coil spring, not shown, having a peg bonded on each opposing end, may be placed inside the base 5 of the support member 3. As the rod 4 is extended down into the base 5, the pegs may be depressed, allowing rod 4 and base 5 to join. When the pegs are released, the spring will cause the peg to mate the rod 4 and base 5 together at the desired hole 4x.
While my detailed description contains many specificities, these should not be construed as limitations on the scope of the invention FIG. 1, but rather as an exemplification of one preferred embodiment of it. Many other variations are possible. The following are examples of such variations:
Perforations' 11 may be located anywhere in the two-part platform 9, thus to increase or decrease the rate of residual water flow;
The primary 1 and secondary tray 2, may be affixed by a standard clamp, or a standard screw;
Receptacles' 6,7,8 may be used to hold nail polish and other applicable supplies and needs for pedicures;
The two-part platform 9, may contain one or more receptacles' 6,7,8 with different dimensions and capabilities;
The support member 3 may contain more or fewer holes' 4x, 5x;
The support member 3 and/or the platform 1 may consist of one or more parts.
Accordingly, the scope of the invention FIG. 1 should be decided not by the embodiments illustrated, but by the appended claims and their legal equivalents. | A combined foot support and grooming needs holder device, designed to securely provide elevation and support for a human foot and grooming needs, while washing, drying, pedicuring the foot or shaving the leg, for use inside or outside of the shower or bath tub. The present invention consists of a two-part single legged elongate support member and a two-part platform, so that the human foot and grooming needs may be located near each other while in use. | 0 |
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This patent application is a continuation of U.S. patent applications Ser. Nos. 15/290,452 and 14/812,188 and claims priority and benefit of U.S. provisional patent application No. 62/030,724. U.S. patent application Ser. No. 15/290,452 is a continuation of U.S. patent Ser. No. 14/812,188 and claims priority and benefit of U.S. provisional patent application No. 62/030,724. U.S. patent Ser. No. 14/812,188 claims priority and benefit of U.S. provisional patent application No. 62/030,724. U.S. patent application Ser. No. 15/290,452 is titled “Automatic Creation of Applique Cutting Data from Machine Embroidery Data,” and was filed Oct. 11, 2016. U.S. patent application Ser. No. 14/812,188 is titled “Automatic Creation of Applique Cutting Data from Machine Embroidery Data,” was filed Jul. 29, 2015, and issued as U.S. Pat. No. 9,492,937 on. Nov. 15, 2016. U.S. provisional patent application 62/030,724, titled “Automatic Creation of Applique Cutting Data from Machine Embroidery Data” was filed on Jul. 30, 2014. U.S. patent applications Ser. Nos. 15/290,452 and 14/812,188 and U.S. provisional patent application 62/030,724 are all herein incorporated by reference in their entireties.
TECHNICAL FIELD
[0002] Embodiments are related to sewing, embroidery, embroidery machines, embroidery design software and automated cutting machines.
BACKGROUND
[0003] Applique is often done by labeling the color steps with the words “Applique” and either “Position” or “Material.” The steps always have to be in order. The first sewn section is the Position. This sewing puts an outline on the project being embroidered. This outline is the location of the material applique which that will be applied to a project cloth at this point in time. The next sewing step is the “Material” which can vary in type of stitch, such as single run, double (out and back), or even zigzag. This sewing anchors the material of the applique to the project. The next step a sewer must do is to cut the applique around the outside of the stitches sewn by the ‘Material’ step. They do this by hand using a pair of scissors generally. Once the excess fabric is removed, the sewing is completed to finish the project.
[0004] Alternatively, a sewer can run the outline of the design on some other item such as paper. This allows them to place the paper with the outline on the cloth that is to be the applique, allowing the sewer to cut the paper and cloth together. This saves loss of registration by the machine during the sewing process.
[0005] Yet another alternate method is to print out a precise template of the applique position color using a normal printer and software that is calibrated for this purpose. All of these methods require the user to hand-cut the applique cloth.
[0006] A different process also exists, wherein certain dies have been made to cut cloth. AccuQuilt.com has typical examples. The dies using manual or pneumatic or electrical means can cut the cloth. This means the cloth must be applied using a sewing machine, not with embroidery.
[0007] U.S. Pat. No. 6,600,966 titled “SOFTWARE PROGRAM, METHOD AND SYSTEM FOR DIVIDING AN EMBROIDERY MACHINE DESIGN INTO MULTIPLE REGIONAL DESIGNS” issued to Brian D. Bailie on Jul. 29, 2003. U.S. Pat. No. 6,600,966 is herein incorporated by reference in its entirety for its teachings of embroidery techniques, embroidery file formats, embroidery file reading/writing/modification, use of grids, analysis software applied to embroidery, identifying and using embroidery regions, and automated and computerized embroidery.
[0008] U.S. Pat. No. 6,633,794 titled “SOFTWARE PROGRAM AND SYSTEM FOR REMOVING UNDERLYING STITCHES IN AN EMBROIDERY MACHINE DESIGN” issued to Brian D. Bailie on Oct. 14, 2003. U.S. Pat. No. 6,633,794 is herein incorporated by reference in its entirety for its teachings of embroidery techniques, embroidery file formats, embroidery file reading/writing/modification, use of grids, analysis software applied to embroidery, identifying and analyzing individual stitches in their context in an embroidery design, and automated and computerized embroidery.
[0009] U.S. Pat. No. 6,732,008 titled “SOFTWARE PROGRAM AND SYSTEM FOR EVALUATING THE DENSITY OF AN EMBROIDERY MACHINE DESIGN” issued to Brian D. Bailie on May 4, 2004. U.S. Pat. No. 6,732,008 is herein incorporated by reference in its entirety for its teachings of embroidery techniques, embroidery stiches, embroidery file formats, embroidery file reading/writing/modification, use of grids, analysis software applied to embroidery, identifying and analyzing individual stitches in their context in an embroidery design, and automated and computerized embroidery.
[0010] U.S. Pat. No. 6,944,605 titled “EXPERT SYSTEM AND METHOD FOR CREATING AN EMBROIDERED FABRIC” issued to Brian D. Bailie on Sep. 13, 2005. U.S. Pat. No. 6,944,605 is herein incorporated by reference in its entirety for its teachings of embroidery techniques, stiches, fabrics, analysis. Further reasons for incorporating U.S. Pat. No. 6,944,605 in its entirety is its teaching of creating and applying rules in the context of embroidery, its teaching of analysis for offering recommendations to human operators, its approach to embroidery design flow, and its parametric selection teachings.
[0011] U.S. Pat. No. 7,457,683 titled “ADJUSTABLE EMBROIDERY DESIGN SYSTEM AND METHOD” issued to Brian D. Bailie on Nov. 25, 2008. U.S. Pat. No. 7,457,683 is herein incorporated by reference in its entirety for its teachings of embroidery techniques, embroidery stiches, embroidery file formats, embroidery file reading/writing/modification, analysis software applied to embroidery, identifying and analyzing individual stitches in their context in an embroidery design, and automated and computerized embroidery.
[0012] Prior art references having different authorship are now presented. The references are also incorporated by reference in their entirety for their teachings of certain aspects of embroidery, embroidery techniques, and the automation of aspects of embroidery processes.
[0013] U.S. Pat. No. 4,920,902 titled “Automatic pattern sewing machine” issued to Takenoya et al. on May 1, 1990. It is herein incorporated by reference for its teachings of a machine that automatically sews patterns, teaching of applique techniques, teachings of pattern data, and teachings of automatic or assisted modification of the pattern data.
[0014] U.S. Pat. No. 1,741,620 titled “Hemstitched applique work and process of making the same” issued to Fixler on Dec. 31, 1929. It is herein incorporated by reference in its entirety for its teachings of stitches, embroidery, and embroidery Knowhow.
[0015] U.S. Pat. No. 8,557,078 titled “Applique printing process and machine” issued to Marino et al. on Oct. 15, 2013. It is herein incorporated by reference in its entirety for its teachings of automatically producing an applique based on a printing type process, for its teachings of certain embroidery/applique techniques, and for its teaching of cutting cloth/materials for appliques.
[0016] U.S. Pat. No. 5,438,520 titled “Method of creating applique data” issued to Satoh et at on Aug. 1, 1995. It is herein incorporated by reference in its entirety for its teachings of applique techniques, applique data, generation and manipulation of applique data, and for the machinery and equipment (embroidery machine, computer, cutter, etc.) that can be used in association with designing and creating appliques.
[0017] U.S. Pat. No. 7,882,645 titled “System and method for making an applique” issued to Boring on Feb. 8, 2011. It is herein incorporated by reference in its entirety for its teachings of applique techniques, applique templates, and applique design.
[0018] U.S. Pat. No. 3,226,732 titled “Applique article and method of manufacture” issued to Zerilli on Jan. 4, 1966. It is herein incorporated by reference in its entirety for its teachings of applique techniques, applique layers, and applique design, cutting, stitching and application.
[0019] Three related patents are also incorporated herein by reference in their entirety. U.S. Pat. No. 5,430,658 titled “METHOD FOR CREATING SELF-GENERATING EMBROIDERY PATTERN” issued to Davinsky et al. on Jul. 4, 1995. U.S. Pat. No. 5,668,730 titled “METHOD FOR AUTOMATICALLY GENERATING CHAIN STITCHES” issued to Tsonis et al. on Sep. 16, 1997. U.S. Pat. No. 5,771,173 titled “METHOD FOR AUTOMATICALLY GENERATING A CHENILLE FILLED EMBROIDERY STITCH PATTERN” issued to Tsonis et al. on Jun. 23, 1998. These three patents largely have the same inventors and are included by reference herein in their entireties for their teachings of developments and refinements in defining, outlining, and filling embroidery shapes. They are also incorporated by reference for their teachings of automatic or algorithmic generation of chain stitch outlines, of automatic or algorithmic generation and of embroidery patterns, of computer aided design applied to embroidery, of embroidery techniques and processes, and for their detailed teachings of stitch types, properties, and uses.
[0020] A document titled “A Survey of Polygon Offseting Strategies” by Fernando Cacciola was incorporated into the filing of U.S. provisional patent application 62/030,724 and is thereby also herein incorporated by reference in its entirety. It is incorporated herein for its teachings of techniques for offsetting polygons and for other transformations and operations.
[0021] Applique is a popular technique and embroidery designs for applique exist in abundance. Systems and methods for saving the sewers time by producing properly cut out designs are needed.
BRIEF SUMMARY
[0022] The following summary is provided to facilitate an understanding of some of the innovative features unique to the disclosed embodiments and is not intended to be a full description. A full appreciation of the various aspects of the embodiments disclosed herein can be gained by taking the entire specification, claims, drawings, and abstract as a whole.
[0023] Aspects of the embodiments address limitations and flaws in the prior art by analyzing machine embroidery data to automatically produce cutting data that a cutting machine can interpret to cut out the applique. An applique data file specifies an applique design and contains sewing data. The sewing data can include sewing vectors and jump commands. The sewing vectors specify stitches as, for example, movements, stitch points, or needle penetrations. The jump commands split the sewing vectors into subsections. For example, one subsection can be an applique outline while a number of other subsections can be holes or openings in the applique outline. An embroidery machine can read and interpret the applique data file to thereby stitch a pattern onto a piece of cloth. A cutting machine can read the cutting data automatically created by the embodiments disclosed herein and cut the applique out of a piece of cloth.
[0024] Aspects of the embodiments can be a non-transitory memory containing program instructions readable by a computer for performing certain operations. Other aspects of the embodiments can he the steps or operations performed in automatically creating the cutting data from the applique data file.
[0025] It is, therefore, an aspect of the embodiments to access an applique data file and to create lists of sewing vectors. If there is only one subsection, then there is only one list. If a jump command splits the sewing vectors into two or more subsections, then there can be two more or lists.
[0026] It is also an aspect of the embodiments to normalize the lists. Normalizing the lists by discarding certain sewing vectors or data such as tie-off data, double stitches, and other sewing artifacts do not affect the applique outline that is to be cut.
[0027] It is a further aspect of the embodiments to close the lists. It is possible for the endpoint on a list to be far enough from the start point that one or more additional sewing vectors are needed to close the list so that it defines a closed outline.
[0028] It is a yet further aspect of the embodiments that an outline contains holes. The closed paths specified by the lists specify at least one outline and may specify a number of holes for applique designs that contain openings. The embodiments can determine that a list is an outline and that another list is a hole. The embodiments can also create objects that include an outline list and one or more hole lists for holes inside the outline.
[0029] It is yet another aspect of the embodiments that the outlines are inflated by a positive amount to make them slightly larger and for the holes to be inflated by a negative amount to make them slightly smaller.
[0030] It is still yet another aspect of the embodiments to simplify the lists by removing points using certain known algorithms such as the Douglas-Peucker algorithm or any of its readily available derivatives. The outline can then be further simplified by fitting them to Bezier outlines using common fitting technique such as Newton-Raphson least squares fitting techniques or other line and curve fitting algorithms that are known in the arts of graphing or computer graphics.
[0031] It is a still yet further aspect of the embodiments to create a preview that can be seen by a person. An image can be produced by copying a first bitmap into the image sections outside of the applique outline and inside any holes in the applique. A second bitmap can be copied into image sections inside the applique outline and outside any holes in the applique.
[0032] An alternative embodiment can use the applique design to draw vectors onto a bitmap. The bitmap should be sized such that it >is large enough to include all the vectors and also large enough that the shortest vector is at least two pixels long. The bitmap can then be conditioned to produce a better outline. Thinning algorithms and skeletonizing algorithms can condition the bitmap. The applique outline can then be traced by finding a first pixel in the outline and then simply following along the outline. Cutting data can be produced from the applique outline traced in the image. Those familiar with image processing and digital image manipulation are familiar with a number of common thinning an skeletonizing algorithms.
BRIEF DESCRIPTION OF THE DRAWINGS
[0033] The accompanying figures, in which like reference numerals refer to identical or functionally similar elements throughout the separate views and which are incorporated in and form a part of the specification, further illustrate the present invention and, together with the background of the invention, brief summary of the invention, and detailed description of the invention, serve to explain the principles of the present invention.
[0034] FIG. 1 illustrates a high level diagram of a processor executing stored instructions to create a cutting data file from an applique data file in accordance with aspects of the embodiments;
[0035] FIG. 2 illustrates a high level block diagram of data transformations and processes to create a cutting data file from an applique data file in accordance with aspects of the embodiments;
[0036] FIG. 3 illustrates a high level block diagram of data transformations and processing of a bitmap to create a cutting data file from an applique data file in accordance with aspects of the embodiments;
[0037] FIG. 4 illustrates an image with irregular edges in association with automated global underlay in accordance with aspects of the embodiments;
[0038] FIG. 5 illustrates an image of needle penetrations in association with automated global underlay in accordance with aspects of the embodiments;
[0039] FIG. 6 illustrates the image of FIG. 5 after triad filtering in association with automated global underlay in accordance with aspects of the embodiments;
[0040] FIG. 7 illustrates the image of FIG. 6 after simplification of the outline and inflation in association with automated global underlay in accordance with aspects of the embodiments;
[0041] FIG. 8 illustrates a tatami fill of the image of FIG. 7 in association with automated global underlay in accordance with aspects of the embodiments;
[0042] FIG. 9 illustrates the tatami filled design of FIG. 8 with embroidered letters in association with automated global underlay in accordance with aspects of the embodiments;
[0043] FIG. 10 illustrates an echo quilting design with embroidered letters in association with automated echo quilting in accordance with aspects of the embodiments;
[0044] FIG. 11 illustrates an automatically generated pattern around embroidered letters in association with automated stippling in accordance with aspects of the embodiments;
[0045] FIG. 12 illustrates an automatically generated pattern from a “Drunkard” algorithm in association with automated stippling in accordance with aspects of the embodiments;
[0046] FIG. 13 illustrates an automatically generated less randomized version of the “Drunkard” pattern of FIG. 12 in association with automated stippling in accordance with aspects of the embodiments;
[0047] FIG. 14 illustrates an automatically generated “Leafy” version of the “Drunkard” pattern of FIG. 12 in association with automated stippling in accordance with aspects of the embodiments; and
[0048] FIG. 15 illustrates an automatically generated “Geometric” version of the “Drunkard” pattern of FIG. 12 in association with automated stippling in accordance with aspects of the embodiments.
DETAILED DESCRIPTION OF THE INVENTION
[0049] The particular values and configurations discussed in these non-limiting examples can be varied and are cited merely to illustrate embodiments and are not intended to limit the scope thereof.
[0050] The embodiments will now be described more fully hereinafter with reference to the accompanying drawings, in which illustrative embodiments of the invention are shown. The embodiments disclosed herein can he embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. Like numbers refer to like elements throughout. As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items.
[0051] The disclosed embodiments are described in part below with reference to flowchart illustrations and/or block diagrams of methods, systems, and computer program products and data structures according to embodiments of the invention. It will be understood that certain blocks of the illustrations, and combinations of blocks can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions/acts specified in the block or blocks.
[0052] These computer program instructions may also be stored in a non-transitory computer-readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner such that the instructions stored in the computer-readable memory produce an article of manufacture including instruction means which implement the function/act specified in the block or blocks.
[0053] The computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions/ads specified in the block or blocks.
[0054] FIG. 1 illustrates a high level diagram of a processor 104 executing stored instructions 102 to create a cutting data file 107 from an applique data file 105 in accordance with aspects of the embodiments. A non-transitory processor readable medium 101 contains the stored code representing instructions 102 that the processor 104 running in computer 103 accesses. The processor 104 accesses applique data file 105 and processes the sewing data 106 to produce cutting file 107 . A cutter 109 provided with applique cloth 108 can process the cutting data file 107 to thereby cut out an applique 110 . An embroidery machine 112 provided with cloth 111 and applique 110 can process applique data file 105 to thereby sew the applique onto the cloth 113 .
[0055] FIG. 2 illustrates a high level block diagram of data transformations and processes to create a cutting data file 107 from an applique data file in accordance with aspects of the embodiments. The applique data file contains sewing data 106 . The sewing data contains sewing vectors 201 and jump commands 202 . There are also sewing artifacts 203 in the sewing data 106 . Examples of sewing artifacts 203 include data for tie-offs, double stitching, and sewing paths that cross in on themselves without stopping.
[0056] Two lists 204 , 207 are created from the sewing data 106 because, in this example, the sewing data 106 contains a jump command 202 . The sewing vectors 205 before the jump command can go into list 1 204 while the sewing vectors 208 after the jump command can go into list 2 207 . In practice, more jump commands can result in more lists being created. Furthermore, list 1 204 and list 2 207 do not contain jump commands.
[0057] The lists 204 , 207 are normalized to remove sewing artifacts 206 , 209 . Analysis indicates that list 2 defines a closed path, meaning that the first and last points in the list of sewing vectors are closer than a predetermined threshold. Analysis indicates the list 1 204 does not define a closed path. List 1 204 is amended to produce list 1 209 containing sewing vectors 210 wherein the path is closed by adding additional sewing data to the list to thereby close the path. For example, a stitch can be added that connects the first and last points.
[0058] List 1 209 and list 2 207 are analyzed and it is determined that the closed path defined by sewing vectors 208 lies inside of the closed path defined by sewing vectors 210 . List 1 209 therefore defines an outline while list 2 207 defines a hole inside the outline. List 1 209 and list 2 207 are combined into object 1 211 because the hole is inside the outline. Object 1 211 can then be inflated by inflating the outline by a positive amount and inflating the hole by a negative amount. In the example, list 1 209 has been inflated by a positive amount into list 1 212 while list 2 207 has been inflated by a negative amount into list 2 213 .
[0059] Inflation is a common geometric term which is slightly different than scaling. It is also known as polygon offsetting and is well known in the art. Where there are ‘Holes’ the inflation uses a negative value, thus reducing the size of the hole.
[0060] Object 1 can be simplified to include simplified lists such as list 1 214 and list 2 215 . Simplification is the elimination of extra points in the sewing data. There are a number of well-known algorithms such as Douglas-Peucker and its derivatives that eliminate extra points. The outline and hole can also be fitted to Bezier outlines using common fitting techniques such as Newton-Raphson or least squares fitting techniques.
[0061] Object 1 can then be transformed into cutting data because the object's data is forward moving, non-repetitive, and possibly spline or cubic Bezier format that is useful to a cutter.
[0062] FIG. 3 illustrates a high level block diagram of data transformations and processing of a bitmap 307 to create a cutting data file 107 from an applique data file 105 in accordance with aspects of the embodiments. The applique data file 105 , in an embroidery file format, contains>an applique design 301 with sewing data 106 . The sewing data can contain sewing vectors 201 , jump commands 202 , and sewing artifacts 203 . Exemplary sewing vectors 201 include stitches 302 , movements 303 , or needle penetrations 304 .
[0063] A bitmap 307 is created that is sized at least as large as the design size 306 and such that the shortest sewing vector 305 is at least two pixels long. The sewing vectors are then drawn onto the bitmap 308 . The bitmap can be conditioned 309 by applying a thinning algorithm or a skeletonizing algorithm. The bitmap can then be traced to find a point on the outline and then the outline traced 310 to produce a list, as discussed above. The list is closed if analysis finds that it is open. The cutting data 107 can then be produced from the list.
[0064] The embodiments can consist of the usual apparatus of a computer, a program, and an embroidery machine. The software can look for sections of the design with appropriate labels. It also allows the user to select a section for applique. The software uses the sewing data (stitches) which consist of a series of relative or absolute movements (vectors or stitch points or needle penetrations) to create an outline. That outline is then saved in a format that is useful to a cutting machine. Cutters, similar to the vinyl cutters used by sign shops everywhere, have been adapted to the purpose of cutting fabric recently. Currently, the cutters force the user to draw the outlines for the cut using a manual drawing process—using bezier or point input modes. In some cases, they can scan in a picture and auto-trace an outline. These are separate sets of steps which are prone to terrible inaccuracy when making the outline.
[0065] The process for converting is not a simple matter of converting formats of the sewing vectors into cutting vectors. The stitch data for an applique position may contain a set of vectors that handle multiple outlines, including holes in outlines, as well as sewing requirements such as tie-offs which are extra stitches that ensure the thread is working and able to be cut between sections. What's required is forward-moving-only data that forms closed polygon outlines.
[0066] Exemplary descriptions of steps and instructions for performing the process are now provided.
[0067] The stitch data may contain both normal sewing vectors and “jump” commands. These jumps are non-sewing movement commands. When the process sees these commands in the data, it can separate the data into subsections, organized as linked lists with each subsection containing the sewing vectors between two jump commands. The end cases, obviously, are the sewing vectors from the stitch data start to the first jump command and the sewing vectors from the last jump command to the end of the stitch data. Note that here linked lists are used in the interests of a simple explanation whereas, in practice, different data structures such as arrays, trees, hash tables, key-value pairs, etc., can be used to similar effect.
[0068] The lists, aka subsections, are now processed into normalized data, which removes certain sewing artifacts.
[0069] For each list:
[0070] Advance a few stitches into the data, looking for a Euclidean distance of travel away from the start point, (2 mm best current) until a new point is found. Once that is reached, the skipped stitch data in between can be discarded. This process is referred to as ‘skipping tie-off data’ and is used throughout. This Euclidean distance and any of the other tolerances or distance discusses below can be user specified parameters having default values or can be constant values. Note, Euclidean distance is specified here as it has proven useful although other distance measures such as Mahalanobis, Manhattan, etc., can be used in appropriate circumstances.
[0071] It is entirely possible for the path to continue around its required outline and past the start point, and it frequently does. The process therefore scans the data iteratively and tracks its path. When and if the path comes back within a tolerance, the closing distance, of the start point, the shape is assumed closed at that point, and that section of data is saved for later processing. The closing distance is typically a distance from the current stitch end to the start point. If found, the stitch whose end is within the closing distance is the closing stitch for that particular shape.
[0072] If the length of the design, meaning the total length of all vectors is below a threshold, threshold, or the number of useable points is too small (a line, not a polygon), then the list is discarded. The data may be double-stitched, wherein the stitches travel to an endpoint, then reverse direction of travel to come back at or near the start point. Therefore the process scans the data looking for double-stitches and removes the double-back section. The process also discards any data beyond the closing stitch.
[0073] It is possible that the data at this point does not form a properly closed path and there is no closing stitch. The path is closed in the usual manner of adding a new tail point between the closing stitch and the start point which closes the outline.
[0074] It is also possible that a stitch other than a single or double stitch may exist in the stitch data. This can be determined by analyzing the points in the data and seeing how many are repeated within a certain tolerance, usually 0.2 mm. If there is a plurality of these, an alternate method must be used on this data to get a set of points that run in a forward direction. This can be accomplished with an alternate process, such as:
[0075] Alternate Method:
[0076] Create a 2-color (e.g., black and white) bitmap that will represent the image, using a pixel ratio that is known so that the vectors will have meaningful scale when drawn such as the shortest vector having a length of two or possibly more pixels. Draw the stitches into the bitmap. Apply a thinning algorithm to the bitmap which will provide sensible single-pixel data. Scan the bitmap for a starting pixel and follow the outline, tracing the path. Thinning algorithms are suggested here because they have been used with success. Other well-known image processing algorithms can similarly skeletonize an image or bitmap.
[0077] These steps are well known in all areas of computer graphics, but not used in the embroidery art for this purpose. Once a plurality of pixels has been discovered, the results are checked against the same steps as above for length and closure. If it is long enough, but open, then it is closed.
[0078] Alternate method:
[0079] The user might use an image of the, stitch data and draw on top of it using ordinary computer drawing tools to create an outline from scratch. This is also useful if the user wants to add an applique section to a design that currently does not have one, but is a good candidate (visually) for one.
[0080] Sequencing the resultant lists.
[0081] Now that we have a plurality of lists containing clean forward-moving-only vector data (cutters don't like a lot of reversals), we can now sort them into outlines and holes.
[0082] For each point-list, analyze the remaining point-lists to see if they wholly contain this list. This is achieved using the Winding Number rule, or any similar technique. Lists which are not wholly contained are separated into a group of ‘outline’ lists, and holes are left in the list of point-lists.
[0083] Next each hole is analyzed to see which outline contains it, and they are grouped together. This group is an ‘object’. Each object has a single outline and possibly a plurality of holes. There may be several objects.
[0084] Optionally:
[0085] As applique cloths will need to be attached to the cloth being embroidered, there are always stitches provided to do so in the applique design. These stitches are known as the ‘Material’ stitches. These stitches are either automatically generated or hand-laid by the artist who is creating the design. Often times the automatic creation of these material stitches uses the exact same form and size as the outline of the applique. This process can work if the applique is hand cut by the sewer after the applique has been sewn. However, if the applique is cut in advance, the material stitching may not penetrate the applique cloth, as the applique cloth will be the same size as the stitching. Therefore at the direction of the user, or automatically, the outline of the applique shape may be inflated before cutting. Making this decision can be done as simply as examining the size of the applique and the size of the material stitching, and if they are within a small tolerance (1-2 mm) then the inflation needs to occur.
[0086] Inflation is a common geometric term which is slightly different than scaling. It is also known as polygon offsetting and is well known in the art. Where there are ‘Holes’ the inflation uses a negative value, thus reducing the size of the hole.
[0087] Optional, depending on the needs of the cutter device:
[0088] Now, each point-list within each object is processed by simplification —thus eliminating extra points which can make the cut difficult. The algorithm used is one created by Douglas-Peucker or any readily available derivative. Then the outlines are fitted to Bezier outlines using a common fitting technique such as Newton-Raphson least squares fitting techniques.
[0089] Finally each object's data, now in forward-moving, non-repetitive, possibly spline or cubic Bezier format is ready for output to a cutter. The cutters each have a format for their data. A typical example is the HPGL.plt format, which is widely used, although there are many proprietary formats too.
[0090] Additionally:
[0091] Once a cut outline (cutline) has been created, it is possible to store this cutline alongside the sewing data in the apparatus. This adds a novel benefit of being able to allow the user to select an image, or for the software to create one, simulating fabric of a given or user-chose color, which image is then used in the display to the user for visualization of the applique. The process of display uses the cutline, which is always a closed shape as described, and a pair of bitmaps which will be used to represent the image. The first image is called a bitmap mask and this image is filled with a background color of known value. Then the cutline is drawn on the mask with a different color. The cutline is always at least one pixel, smaller on each edge in its representation on the bitmap than the bitmap size.
[0092] A loop is run for each pixel in the bitmap and, an evaluation is made—if the pixel is background colored data, a determination of that point and whether or not it is inside the actual object is made. Inside is determined true if the point is within the outline, and not within any holes. If it is determined that the point is inside the object shape, then a seeded fill operation is performed, which is a color that fills the inside area, and that color is not background. At the end of the loop the mask bitmap contains a binary image of pixels which are either background or contained in the object.
[0093] The next step is to use an image, represented by another bitmap, and placed over the mask bitmap, and a display bitmap. Where the mask bitmap contains drawn pixels, the matching pixel from the image is copied into the display.
[0094] In a previous step, the input image may be selected by the user and certain transforms applied, including brightness, contrast, sepia tone, hue and saturation adjustments for the purpose of matching other colors and even editing may be performed. All of which steps are common to the computer graphics art, and included as a step in the process.
[0095] It is not assumed that masked bitmaps are novel. Just the implementation of them in the place is described. There are also transforms that can be applied, too numerous to mention, but by example: rotation, morphing, and alpha channel.
[0096] Another Addition:
[0097] Prior art (Bailie) has disclosed a method for removing overlapping stitches from a design. This improves the design by removing density which results in damage to equipment, downtime, and even simple production time. The new outline and masked bitmap allows the process to be extended in such a way that the applique material is now an additional component of the occlusion—causing, other stitches which are previously sewn to be unnecessary. Their removal is very useful for the same reasons just mentioned.
[0098] An additional item is useful: Tagging the sewing data which are Position and Material runs as NOT to be removed is useful. This stitch data which would be removed during the process normally can now be exempted from the removal. The reason is that Position and Material runs are required where applique materials will be overlapped, according to the designer of the embroidery design. In this case, the stitches that are not part of Position and Material stitches should be removed, and would be, as the subsequent applique would cover them.
[0099] Aspects related to automatic global underlay for embroidery designs:
[0100] It is often desired to place embroidery on towels or any other items that are composed of a cloth with a texture known as pile. This poses difficulty for the embroiderer as the process of embroidery on that kind of cloth requires a substantial number of stitches to flatten out that cloth before the design is sewn. If the underlying stitches are insufficient, the design will have the texture of the cloth protruding above the embroidery and/or making the texture of the embroidery irregular.
[0101] As most designs are not created with this intended purpose, it would be beneficial if there were a way to automatically add such an underlay to any design. This can he accomplished using (the usual apparatus) plus a set of bitmaps, and stitch-creation process.
[0102] First a masked bitmap is created. It is filled with no color (black). Then, using a single color, the design is drawn into it. This image when rendered usually has a very irregular edge, one not pleasing to the eye. Due to the nature of stitch data, the bitmap is rendered using LineTo and MoveTo commands, which leave “>” shaped gaps all along the edges of adjacent lines of stitching as can be seen in FIG. 4 .
[0103] If a path-following process around the image is used, these “<” or “>” shaped dents are formed. Nonetheless, a set of traces around the drawn design must be the start of the process. However, additional drawing in the form of a different color, only at points of needle penetration can be, performed as shown in FIG. 5 .
[0104] This allows the outline to have more intelligent data and thus the resultant paths can have the pixels between the penetrated points removed. This makes the outline more regular and pleasing. Further improvement can be made by filtering triads of stitch points which are close together, often the result of embroidery short-stitching, which is commonly used as a method to turn the angle of lines of stitches. FIG. 6 is an image of such a filtered image.
[0105] Next a simplification of the outline can be made and conversion into Bezier or other outline form thus made.
[0106] As there are likely to be a plurality of outlines, it is important to create objects with outlines and holes, as described previously.
[0107] Once those outlines exist, a global underlay can be achieved by first, inflating the size of the shapes to some useful value (best practice is 3 mm) as seen in FIG. 7 .
[0108] Then those shapes can be passed to a tatami fill generator which is well defined in the art (best practice for Terry cloth is 3.5 mm stitch length, 1.5 mm line density). The output of the fill generator can then be sequenced as the earliest-sewn data in the design. Thus with a single user action, the process can adapt any design to the desired nappy cloth. Additionally, using the prior art, any stitch data from the original design which is interpreted as underlay may now be removed, as it has been replaced with a superior set of data. FIG. 8 illustrates a tatami fill pattern while FIG. 9 illustrates letters embodied over a tatami filled area.
[0109] Aspects related to automatic echo quilting for embroidery designs:
[0110] Using a similar process to creating a global underlay, wherein the outline and hole data is created for any embroidery design, we can achieve a different effect. The concept of echo quilting is not new to graphics, but in embroidery such items are manually created by a skilled artist. FIG. 10 illustrates an echo quilting design with embroidered letters.
[0111] Outlining stitches with new stitches can be done by taking the objects and handing them to a run stitch generator (or any stitch generator, such as satin, bean stitch, etc.). Further, if we optionally discard any holes, we can then expand the outlines using known polygon inflation techniques to create a single or plurality of outlines which ‘echo’ around the design. This is commonly used by quitters to provide stability to a quilt, using a set of running stitches known as echo quilting. It appears as ripples would in a pond. Further, as each embroidery is constrained by the hoop which will be used to create it, we can cause the echo lines to terminate within the bounds of the hoop, and add tie-off and jump to other echo lines as needed. The user of the software could control the distance and stitch type of the echo lines. Additionally, multiple designs within a hoop could have their outlines inflated together, producing a more visually complex result as the echo patterns interfere with each other, and each echo line can have other stitch actions applied, such as decorative motifs played on the line, etc.
[0112] Aspects related to automatic drop shadow embroidery:
[0113] Using a similar process to creating a global underlay, wherein the ‘outline’ and ‘hole’ data is created for any embroidery design, we can achieve a different effect. The concept of drop shadow is not new to graphics, but in embroidery such items are manually created by a skilled artist.
[0114] In this process, we take a complete set of outlines as proposed above and offset them in a manner described by a user, having little skill and requiring only a visual interest, and offset, inflate with rounding acute corners, monochromatize, and then use a graphical subtraction which created a resulting set of objects that can then have stitches applied. The subtraction includes steps for discovering intersections between the original and copied image, then discarding overlapped regions, however, the drop shadow is compensated such that its shape penetrates the original design by a small amount which is useful in embroidery to prevent gapping in designs, where the background shows through. The user inputs an offset of a vector, containing by definition a distance and an angle. This angle is then used as the angle for a tatami or other patterned fill, well known in the art.
[0115] Aspects related to automatic, stipple embroidery:
[0116] Prior art exists, which has flaws that this overcomes.
1.) Using a similar process to creating a global underlay, wherein the ‘outline’ and ‘hole’ data is created for any embroidery design, we can achieve a different effect. or 2.) Using a user-defined area which typically includes an outer shape, which may be an embroidery hoop area, or some other defined polygon, and optionally an internal area of exclusion such as a design or plurality of designs placed in the hoop area, there is a need to automatically stitch down lines in a pseudo-random order known in the art as stippling. There are several variations on the pattern, but one requirement is near-uniform distance between lines of stitching. And they may not cross.
[0119] Prior art has been shown with fractals (Tsonis . . . , Pulse Microsystems, Mississauga, Canada), but that approach has a failure in that the fractal shape does not match the original shape, and thus there are clipped sections causing the stitch to either jump from section to section (undesirable because of time sewing and trimmer [a mechanical device in the machine] wear) or false paths which are too close.
[0120] Other prior art—Brother JP—uses a method where the pattern can be trapped and requires an exit to find its way out, which causes the lines of stitching to be closer together than optimal.
[0121] These embodiments solve that using maze theory and algorithms, with adaptations for embroidery.
[0122] A plurality of tessellated shapes, which may or not be identical in shape, is laid over the desired embroidery region at potentially a user-defined angle, with added spacing between the tessellations, defining graphical cells in a matrix. Each cell has data with it describing its center and the position and state of each edge, along with each edge's availability of an adjacent neighbor. Cells with fewer than two edges that are completely contained in the outline are discarded from the matrix.
[0123] As there is a minimal irregularity sometimes desired in stippling, the centers may be randomly offset by some small vector.
[0124] Shapes which are partially contained are flagged as such, along with the edges that are available for use in the design (those contained in the shape).
[0125] An initial starting point is defined, either randomly or by the user. The software then follows an algorithm (Drunkard's Path example) for selecting and adding cells to the sequence, labeling used cells as it goes, thereby ensuring that a single path can be traced into each and every useable cell in the matrix. Due to the nature of randomization added to the algorithm, the path is always different, although the seed used can be stable or user-altered to change the path. To ensure that the accidental use of continuous forward moves does not occur, the randomizer is presented with a reduced solution set where advancing forward in the same direction as the last move occurred happens. This makes the path turn frequently.
[0126] Once the path has been established, there needs to exist a return route in order to achieve the desired effect. For this reason, the actual entry and exit of each cell has its points set at evenly spaced intervals along the edge where travel exists. Thus, the path always forms a closed shape, running twice through each and every cell.
[0127] Where the path enters a cell is stable, as that maintains spacing between lines of stitching. Instead of following through the cell, however, the stitches run around the edges of the cell toward the exit edge. This provides additional shape and visual interest to the pattern. This is made possible by the cell spacing, which allows the edges not to touch.
[0128] Additional adjustment is made to the points discovered as the path travels through the cells. For each cell where the path enters and then exits, without going through another cell, this cell is flagged for shape adjustments.
[0129] The nodes of each entry, exit, and edge travel are set into a list, each given a Bezier handle set (or spline). In the case of Bezier, the handles may be adjusted in length and rotation by small amounts to create imperfect curvature, similar to what a skilled sewer would do by hand. Additional effects can be the lack of curvature and/or the erasure of nodes based on patterns. This produces a random, yet geometrically pleasing image.
[0130] Further, the resultant shape can now be taken as an outline and passed to other stitch generating apparatus. In this way motifs (or any other ornamentation) can be added.
[0131] A variation of this exists and is known in the industry as “Vermicelli Stitching.” This is similar in that it is random movements of small vector length and those movements are allowed to clip against the actual outlines. In this case we take the original stipple path and allow it to enter any cells that even touch the outline. A similar operation is performed, yet with a simple rule system for internal deformation of each cells travel route. The result is very similar to a manual process that is extremely time-consuming.
[0132] FIG. 11 illustrates an automatically generated pattern around embroidered letters in association with automated stippling in accordance with aspects of the embodiments.
[0133] FIG. 12 illustrates an automatically generated pattern from a “Drunkard” algorithm in association with automated stippling in accordance with aspects of the embodiments.
[0134] FIG. 13 illustrates an automatically generated less randomized version of the ‘Drunkard’ pattern of FIG. 12 in association with automated stippling in accordance with, aspects of the embodiments.
[0135] FIG. 14 illustrates an automatically generated “Leafy” version of the “Drunkard” pattern of FIG. 12 in association with automated stippling in accordance with aspects of the embodiments.
[0136] FIG. 15 illustrates an automatically generated “Geometric” version of the “Drunkard” pattern of FIG. 12 in association with automated stippling in accordance with aspects of the embodiments.
[0137] It will be appreciated that various of the above-disclosed and other features and functions, or alternatives thereof, may be desirably combined into many other different systems or applications. Also, that various presently unforeseen or unanticipated alternatives, modifications, variations or improvements therein may be subsequently made by those skilled in the art which are also intended to be encompassed by the following claims. | Using an existing embroidery design that has been created for applique, data is automatically created for a cutting machine, which will cut the applique. Currently, the user currently has to cut these by hand—a labor intensive process or use a custom die that can be expensive. The process only requires that the applique steps in the sewing sequence are labeled as such. Generally, the applique steps are so labeled in order for the design creator to be able to let the sewer know what they are doing. | 3 |
TECHNICAL FIELD
The present invention relates to medical equipment, and more particularly to a tubular surgical drape for creating a sterile environment when conducting a medical procedure on a patient.
BACKGROUND OF THE INVENTION
It has long been known that the uterus of a human female is a sterile environment while the vaginal canal is not. There are many surgical procedures that require passage through the vaginal canal to gain access to the uterus through its cervix (the cervix uteri). For example, the normal insertion of an intrauterine contraceptive device (IUD) is invasive of the uterus via the vaginal canal.
Current practice generally suggests that the physician swab the cervical os with a sterilizing agent, such as betadine, prior to performing an invasive surgical procedure. However, because the surrounding vaginal canal is not sterile, it is extremely difficult to preserve an aseptic technique.
A recent study (see Jacques et al., Am. J. Obstet. Gynecol. 154:648-655, March 1986) has shown that insertion of an IUD through the vaginal canal appears to be a significant cause in the introduction of microorganisms into the uterus. Once microorganisms have entered the uterus, the incidence of pelvic inflammatory disease increases. The study suggested that the IUD's passage through the vaginal canal immediately prior to placement in the uterus is a primary reason of microbial colonization of IUDs.
The present invention facilitates the performance of an invasive surgical procedure to be performed on the human female uterus with a reduced likelihood for microorganism invasion.
SUMMARY OF THE INVENTION
The present invention contemplates a tubular vaginal drape, a drape insertion unit, and a kit for use in conducting medical and/or surgical procedures on the uterus. The vaginal drape helps to maintain an aseptic environment during such procedures.
More specifically, the vaginal drape of the present invention is a gathered or pleated sheet-form tube, i.e., a tube having a foreshortened but expandable periphery. Typically, the tube is made of conventional surgical drape material or the like, and is provided at one end with a special securement means. The tube is open at both ends. At one end, the opening is free-form and can expand to the full circumference of the tube. At the other end, a relatively smaller opening is defined by a peripheral lip such as a flange or a seam. The lip provides a securement means for the drape about the cervix uteri and projects inwardly from the tube.
The relatively smaller opening or aperture is situated at the distal end of the tubular drape relative to the physician. The distal end of the tubular drape is the end to be placed within the vaginal canal of a human female patient and positioned about the cervix. When in place, the tube is expanded as permitted by the geometry of the vaginal canal to provide an aseptic access route to the cervix. The gathered or pleated wall of the vaginal drape protrudes beyond the body cavity. The protruding material portion may be slit to facilitate the positioning of the drape, and/or portions thereof may be rolled up or folded back to conform to the patient.
The distal end of the vaginal drape is retained within the vaginal canal by a securement means such as a bioadhesive, a mechanical attachment means, e.g., a ring stretchable around the cervix or a ring that expands and lodges in the fornices of the vaginal canal, or the like expedients. The securement means temporarily retains the vaginal drape about the cervix while a desired surgical procedure is performed. The drape is removed easily after the procedure.
The vaginal drape can be packaged alone or together with an insertion unit. In the latter case, the insertion unit is constituted by an inner, dispensing cylinder, an outer, retaining cylinder, and the vaginal drape in gathered or pleated form is situated therebetween. The vaginal drape preferably remains gathered or pleated and in a compact, compressed form for shipping and storage by the coaction of the retaining cylinder with the dispensing cylinder.
The insertion unit provides a convenient means for a physician to install the vaginal drape. In particular, the dispensing cylinder is first manipulated to remove the drape from the retaining cylinder and then to position the aperture of the vaginal drape around the cervix uteri.
The dispensing cylinder is pushed through the outer, retaining cylinder while urging the drape into the vaginal canal and allowing the drape material to expand. Once the vaginal drape is secured in place, the inner, dispensing cylinder is removed and the region is ready for a surgical procedure. During insertion, the bore of the dispensing cylinder provides a sighting means for positioning of the drape about the cervix.
With the vaginal drape in place and the cylinders removed, the exposed portion of the cervix is disinfected, thereby creating a sterile environment that reduces the likelihood of an inadvertent introduction of microorganisms into the uterus.
The drape can be sterilized immediately prior to use. Alternatively, to maintain the sterile qualities of a pre-sterilized vaginal drape, a sealed vaginal drape kit can be provided. Such a kit includes the vaginal drape together with the dispensing cylinder and the retaining cylinder contained within a hermetically sealed envelope or pouch. Optionally, the kit may include medical swabs impregnated with a sterilizing agent such as betadine.
Special kits can be provided for specific surgical procedures such as for the insertion of an intrauterine device (IUD). In such instances the IUD can be packed in the kit, if desired. The drape may also be used and kits assembled for other surgical procedures on other parts of the body.
Numerous other advantages and features of the invention will become readily apparent from the following detailed description of the invention, the accompanying drawings, and the claims.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a vaginal drape embodying this invention;
FIG. 2 is a fragmentary perspective view of the insertion unit in its shipment and storage configuration;
FIG. 3 is a fragmentary perspective view of the insertion unit with a portion of the vaginal drape exposed as during a typical insertion;
FIG. 4 is a cross-sectional view showing an insertion unit, the vaginal drape being interposed between the cylinders and provided with a ring-type securement means;
FIG. 5 is an enlarged cross-sectional view showing the coaction of the elements of this invention in the embodiment illustrated in FIG. 4;
FIG. 6 is a cross-sectional view of the insertion unit illustrating an alternative preferred embodiment of the present invention;
FIG. 7 is an enlarged cross-sectional view showing the coaction of the elements of the invention illustrated in the embodiment of FIG. 6;
FIG. 8 is a cross-sectional view of the insertion unit illustrating yet another preferred embodiment of the present invention;
FIG. 9 is an enlarged cross-sectional view showing the coaction of the elements of the invention illustrated in the embodiment of FIG. 8; and
FIG. 10 is a cross-sectional view taken along plane 10--10 of FIG. 2 and showing the kit suitable for conducting a medical procedure through the vaginal canal of a human female.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
While this invention is susceptible of embodiment in many different forms, there is shown in the drawing and will be described hereinbelow in detail certain embodiments thereof with the understanding that the present disclosure is to be considered as an exemplification of the principles of the invention and does not limit the invention to the illustrated embodiments.
Referring to the drawing, FIG. 1 shows an embodiment of the vaginal drape 10 of the present invention. The drape is a sheet-form tube 14 provided with a plurality of gathers, pleats or the like 12 which extend substantially the full length of the drape. These gathers or pleats foreshorten the periphery of the sheet-form tube as packaged or stored, but permit an expansion of the perimeter of the tube along its length as required during use. Creping also can be utilized for this purpose. The tube 14 can be made from various types of sheet-form materials such as nonwoven fabrics, common to the medical industry or may be made of an alternate material, for example, a clear polyethylene or polyethylene terephthalate film, and the like.
The tube 14 is open at both ends. At one end, the distal end of the drape, the gathers or pleats 12 are captured and contained around a relatively smaller opening or aperture 18. At the opposite or proximal end, the gathers or pleats are free and define a relatively larger, free-form opening 16. As shown in FIG. 2, at distal end 18 there is provided a lip 22 which is located about the periphery of the tube 14. Lip 22 projects inwardly from tube 14. Also located at the distal end defining aperture 18 is a securement means 20 which performs the dual purpose of retaining the foreshortening gathers or pleats 12 in compacted form while securing the vaginal drape 10 to the human female's cervix.
Lip 22 can be solely a structural element of the drape, with another element acting as the securement means 20. Alternatively, the lip 22 and the securement means 20 can be combined in a single structural element. In some embodiments of this invention only a securement means 20 is necessary. The several embodiments shown in FIGS. 4-9 and discussed hereinbelow illustrate various securement means and retaining lips such as flanges and the like.
FIG. 2 shows the drape insertion unit 34 in a shipping or storage configuration, while FIG. 3 shows unit 34 with drape 10 partially withdrawn. The insertion unit 34 includes-an outer, retaining cylinder 26 and an inner, dispensing cylinder 24. The vaginal drape 10 is interposed in a compact manner between the inner dispensing cylinder 24 and the outer, retainer cylinder 26. Also shown in FIG. 2 are swabs 36 which are an optional accessory of the vaginal drape kit hereinbelow discussed in connection with FIG. 10.
Preferably, retaining cylinder 26 is shorter than the dispensing cylinder 24. The preferred embodiment includes a retaining cylinder 26 that completely surrounds at least the distal portion of the tube 14, causing the gathers or pleats 12 to remain compact and a dispensing cylinder that is at least about twice as long as the retaining cylinder.
The lip 22 coacts with one end, the distal end, of the dispensing cylinder 24 to dispense and position the drape 10 from within the retaining cylinder 26. Once the drape 10 is in position, the dispensing cylinder 24 can urge the securement means 20 about or over the cervix uteri, depending upon the nature of the desired securement. Swabs 36 can be stored within the chamber defined by dispensing cylinder 24 as shown in FIGS. 2 and 10.
The size of aperture 18 can vary depending upon the size of cervix to be accommodated. Typically, the diameter of aperture 18 is about 3 to about 5 centimeters.
FIGS. 4 through 9 illustrate flanges, securement means, and their coaction with the retaining and dispensing cylinders.
FIGS. 4 and 5 show a flexible ring 132 as the securement means. The flexible rig 132 provides both the abutment lip and the securement means. The flexible ring 132 is attached about the aperture of the pleated tube 114 in a seam of the tube material.
In this manner, securement means are provided without additional structural elements. First, the flexible ring 132 can be elastic and stretchable, so that the exposed portion of the cervix may be drawn into the ring 132 while the latter is stretched or expanded. The ring 132 causes the mucus membrane of the cervix uteri to be temporarily slightly compressed; however, the temporary compression is not so great as to impede the access to the uterus via the cervix but is sufficient to maintain the vaginal drape 110 in place during a medical procedure.
Secondly, depending upon size, flexible ring 132 can be slightly compressed while contained within the retaining cylinder. Once the outer, retaining cylinder 126 is removed, ring expands and lodges in the fornices surrounding the cervix.
Also illustrated by FIG. 5, the flexible ring 132 defines, together with the drape material, a flange 122 upon which a bioadhesive is applied. The bioadhesive serves as the securement means. The drape is positioned by applying pressure against the ring 132 to engage the bioadhesive with tissue contiguous thereto. Suitable bioadhesives are discussed in detail hereinbelow.
In the embodiment illustrated by FIGS. 6 and 7, pleated tube 214 is rolled at its cervix-enveloping end to form a built-up seam 222 which abuts the distal end 223 of dispensing cylinder 224. The built-up seam 222 can have sufficient elasticity to attach to the cervix, or seam 222 can be coated or impregnated with a suitable bioadhesive. During storage, seam 222 is contained within retaining cylinder 226.
Yet another embodiment of the present invention is shown in FIGS. 8 and 9. Pleated drape 314 is contained between retaining cylinder 326 and dispensing cylinder 324. The cervix-encompassing end of drape 314 is provided with peripherally spaced, inwardly extending protuberances 322 that provides an abutment means for distal end 323 of dispensing cylinder 324 as well as an opposite exposed surface or land such as 325 that is coated with a bioadhesive to provide a securement means to body tissue within the vaginal canal.
The drape insertion unit retains the vaginal drape in a foreshortened and a compressed form for shipping and storage. When the drape is to be inserted, the vaginal canal is first opened with a surgical instrument, typically a speculum. Then the insertion unit is placed at or inside the canal as needed, with the dispensing cylinder guiding the vaginal drape to and about the cervix. The retaining cylinder is pulled off the dispensing cylinder in a direction opposite the cervix. FIG. 3 illustrates the manner in which the retaining and dispensing cylinders can be axially shifted, one relative to the other, to effect placement of the vaginal drape. The dispensing cylinder 24 guides the drape and its corresponding securement means to the cervix. Once the drape is secured to or about the cervix, the inner cylinder 24 is removed, the cervix swabbed with a sterilizing agent, and the region is ready for a surgical procedure.
FIG. 3 also shows the swabs 36 which are a part of the vaginal drape kit herein below discussed in connection with FIG. 10.
In the embodiments that use a bioadhesive to secure the vaginal drape 10 to the mucus membrane of the cervix itself, a number of bioadhesives are available for use. Such bioadhesives are chemical compounds that adhere to human mucus membrane and have long been used to attach dentures to the mucus membrane of the gums. Illustrative bioadhesives are available in many forms, for example, sodium carboxymethylcellulose (NaCMC) dispersed in various polymers, then formed into thin films. Another, paste-like bioadhesive is NaCMC in a polyethylene/mineral oil gel base. Suitable other bioadhesives are described in Gurny et al., Biomaterials 5:336-340, (November, 1984); Ch'ng et al., J. Pharm. Sci 74 (4):399-405, (April 1985); and Hui et al., Int. J. Pharmaceutics 26:203-213 (1985).
The vaginal drape can be sterilized immediately prior to use. Alternatively, to preserve the sterile qualities of a pre-sterilized vaginal drape, a sealed kit can be provided. The kit is hermetically sealed by a wrapping so that sterile conditions are preserved through shipping and storing. The wrapping can be a film or other sheet-form envelope, preferably one permeable to a sterilizing gas. Preferably, the wrapping is heat-sealable or heat-shrinkable for ease of packaging. Such a kit includes the insertion unit 34, with the inner, dispensing cylinder 24, the outer, retaining cylinder 26, the vaginal drape 10. A cross section of such a kit is shown in FIG. 10. Included in the illustrated kit are plural cleansing swabs 36 nested inside the inner dispensing cylinder 24. Swabs 36 can be impregnated with a sterilizing agent, such as betadine, if desired.
These kits can be assembled to include other single use devices or instruments used when conducting a medical procedure through the vaginal canal. For example, in an IUD insertion, an IUD could be packaged as part of the kit.
From the foregoing, it will be observed that numerous variations and modifications may be effected without departing from the true spirit and scope of the novel concept of the invention. It is to be understood that no limitation with respect to the device illustrated herein is intended or should be inferred. It is, of course, intended to cover by the appended claims all such modifications as fall within the scope of the claims. | A vaginal drape having a substantially frustoconical configuration, and a perimeter expandable along the length thereof. The drape is adapted to be secured about the cervix uteri of a human female. The vaginal drape can be used alone or in cooperation with an insertion unit or a kit for conducting medical and/or surgical procedures on the uterus. The drape provides an aseptic region while a medical procedure is being performed on the uterus through the vaginal canal. | 0 |
This is a continuation of application Ser. No. 07/321,138, filed Mar. 9, 1989, now abandoned.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to catechol derivatives and their use as medicines. More particularly, it relates to catechol derivatives having the ability to induce production and secretion of nerve growth factor (hereinafter abbreviated as NGF) in the local tissue of the brain. The invention also relates to prophylactic and therapeutic preparations containing these derivatives as active ingredients for regressive disorders of the central nervous system.
2. Description of the Prior Art
Basic and clinical researches have been intensively promoted in order to establish early diagnosis and etiologic therapy for various senile diseases with the increasing average span of life in the world. Regressive disorders of the central nervous system are also one of the principal research subjects. Senile Dementia of the Alzheimer Type (hereinafter abbreviated as SDAT), also known as Alzheimer Disease, a typical disease in particular, is becoming a serious social problem as a result of its increase primarily in advanced countries as well as the progressive and tragic course of the disease.
Particularly in recent years, many researchers and clinicians have investigated extensively and yet neither fundamental elucidation of the disease nor effective early diagnosis and therapy have been established. Many pathological findings, however, have been accumulated on the direct cause of failure of immediate memory and disorientation which are characteristic early symptoms of SDAT. According to these findings, the cause is a progressive degeneration in magnocellular cholinergic tracts projecting from the basal forebrain into the cerebral cortex and hippocampus which are the centers of memory and learning, and an accompaning dysfunction in this responsible region. In addition, precursors in acetylcholine biosymthesis or inhibitors of choline esterase were actually administered to SDAT patients as an activation treatment for the brain cholinergic neuron. Cases of partial improvement have been reported whereas generally the results have been not as effective as expected.
NGF has been the subject of many studies since its discovery by R. Levi-Montalcini and S. Cohen et al. It has already been demonstrated by several experiments in physiological chemistry that NGF is an essential factor for the peripheral nervous system relating to differentiation and growth of sensory and sympathetic nerves in the fetus and further, to the survival and maintenance of functions in the sympathetic neurons of an adult.
NGF, however, is a potent biologically active substance even in ultra trace amounts. In spite of long term studies, precise information has not been obtained on its distribution in the tissue and movement which directly prove vital functions. Most recently, development and improvements have been made using the highly sensitive enzyme linked immunosorbent assay (hereinafter abbreviated as ELISA) to identify the active subunit of NGF, e.g. β-NGF (hereinafter simply referred to as NGF). Thus satisfactory detection-sensitivity and specificity for this examination have been attained [S. Furukawa et al., J. Neurochem., 40, 734-744 (1983); S. Korshing and H. Thoenen, Proc. Natl. Acad. Sci. U.S.A., 80, 3513-3516 (1983)].
Further, the NGF gene has been cloned and structure is analyzed. A method for determining messenger RNA (hereinafter abbreviated as m RNA) for β-NGF has been established using its complemental DNA (hereinafter abbreviated as cDNA) as a probe [D. L. Shelton and L. F. Reichardt, Proc. Natl. Acad. Sci. U.S.A., 81, 7951-7955 (1984); R. Heumann et al., EMBO J., 3, 3183-3189 (1984)].
By applying these procedures, a clear positive correlation has been demonstrated between the grade of sympathetic innervation in the peripheral nervous system and gene expression of NGF in the innervated tissue.
More surprisingly, NGF has also been detected in the central nervous system of rats, particularly in hippocampus, neocortex, and basal forebrain, e.g. septum, olfatory bulb, diagonal band of Broca, and nucleus basalis magnocellularis. In addition, its mRNA content has been found at a high level in the hippocampus and neocortex. On the other hand, the NGF content in the septum of the basal forebrain has been found at a low level as in other regions of the brain where no NGF antigen was detected [S. Korshing et al., EMBO J., 4, 1389-1393 (1985)]. Thereafter the results have been successively traced by other research groups [D. L. Shelton and L. F. Reichardt, Proc. Natl. Acad. Sci. U.S.A., 83, 2714-2718 (1986); S. R. Whittemore et al., Proc. Natl. Acad. Sci. U.S.A., 83, 817-821 (1986)].
According to these results, the NGF gene is expressed not only in the peripheral nervous system, but in the central nervous system as well. Furthermore, it was demonstrated that NGF is produced and secreted in the innervating regions of the chlorinergic tracts projecting from the origins of the basal forebrain to the neocortex and hippocampus, the centers of memory and learning, and then taken up at the nerve endings and transported in a retrograde manner through axons to reach somata in the origins. NGF has already been proven by a series of physiological experiments to be an essential factor for the survival and maintenance of functions in the chlorinergic tracts. These results have demonstrated the assumption that NGF has a specific function as a "neurotropic factor" also in the central nervous system. Thereafter the experiment has been traced by several research groups and has also been proven by investigation of NGF receptors and their distribution in the brain.
The present inventors have investigated the function of NGF as the neurotropic factor in the central nervous system. As discussed in the literature, summarized above, the disorders in memory and learning which are the early symptoms of SDAT are directly caused by the progressive degeneration of cholinergic tracts and consequent dysfunction of brain domains under their control.
The inventors, however, now believe that the failure of production and secretion of NGF in particular regions of brain can be the truly fundamental cause of early symptoms in SDAT. This is because conventional symptomatic trials against SDAT, such as supplementation and/or availability improvement therapies with acetylcholine, have been made without any remarkable result. On the other hand, it is believed that effective therapy may be realized if the functionally vicious cycle between responsible nerves and regions under their control could be broken by maintaining the production and secretion of NGF in the cerebral cortex and hippocampus.
Procedures for preparing human-type β-NGF in a large amounts have already been developed by gene-manipulation, yet many pharmacological and pharmaceutical limitations still exist on achieving supplemental therapy of NGF itself, which is a protein having a molecular weight of above 10,000. To date, there has been no application of NGF to the central nervous system.
It is important from the above viewpoint to investigate low molecular weight compounds capable of inducing the production and secretion of NGF in particular tissues to be used as therapeutics for substantial and effective supplemental NGF therapy. The present inventors have already reported catechol derivatives having such activity (Ikeda: U.S. patent application Ser. No. 07/098554). There are also reports of Furukawa et al. [Y. Furukawa et al., J. Boil. Chem., 261, 6039 (1986) and FEBS Letters, 208, 258(1986)]
SUMMARY OF THE INVENTION
The object of this invention is to provide a medicine capable of inducing the production and secretion of NGF in particular tissues as a substantial and supplemental NGF therapy. That is, to provide a compound having, in regions under the control of specific nerves, acrivity for promoting the production and secretion of NGF which functions as a "neurotropic factor" for the responsible nerves to be administered by usual and convenient method. The compound is administered as it is or as a modified compound in accordance with customary pharmacological and pharmaceutical considerations. It is believed that the compound increases the supplied quantity of NGF into the locus of degenerated nerves and enables these nerves to recover their function. In particular, the compound is usuful for the treatment of SDAT, a disorder in of central nervous system for which fundamental therapy has not yet provided.
In the early onset stage of the SDAT symptoms, peripheral administration of the catechol derivative can enhance the NGF production and secretion ability in the cerebral cortex and hippocampus regions of the central nervous system. The progress of characteristic degeneration in the responsible cholinergic neuron is thereby inhibited. Repair of damaged neurons and reinnervation by surviving neurous are thus promoted.
Therefore this invention provides significant new therapy according to a new mechanism of action depending upon brain plasticity.
The present inventors have investigated low molecular weight compounds capable of inducing the production and secretion ability of NGF in specific tissue. As a result, it has been found that a specific class of catechol derivatives have activity for inducing the production and secretion ability of NGF, and are effective to inhibit the progression and for therapy of regressive disorders of the central nervous system.
One aspect of this invention is a novel catechol derivative, or a pharmaceutically acceptable salt thereof, represented by the formula (I): ##STR1## wherein R 1 is a hydrogen atom or an acetyl group and R 2 is a ##STR2## group or a ##STR3## group, where R 3 and R 4 are each independently a hydrogen atom, alkyl group, cycloalkyl group, aryl group or a substituted aryl group, wherein except for sixteen combinations in R 3 and R 4 , each member is a hydrogen atom or an alkyl group having one to three carbon toms, and wherein R 5 is a hydrogen atom, alkyl group, aryl group, substituted aryl group or an alkoxycarbonyl group, and X is a direct bond, oxygen atom, nitrogen atom or a methylene group.
Another aspect of this invention is prophylactic or therapeutic pharmaceutical preparation for the treatment of regressive disorders of the central nervous system which comprises as the active ingredient a catechol derivative represented by the formula (II): ##STR4## wherein R 6 is a ##STR5## group, ##STR6## group, or a ##STR7## group, where R 1 , R 5 and X are the same as above, and R 3 and R 4 are each independently a hydrogen atom, an alkyl group, cycloalkyl group, aryl group or a substituted aryl group and R 7 and R 8 are each independently a hydrogen atom, a lower alkyl group or a lower alkanoyl group and R 9 is a hydrogen atom or a lower alkyl group, and n is an integer of 1, 2 or 3, wherein except when R 1 , R 7 and R 8 are hydrogen atoms and n is an integer of 2 and when R 1 and R 7 are hydrogen atoms, R 8 is a methyl group and n is an integer of 2.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
As examples of the substituent in the catechol derivative represented by the formulas (I) and (II) of this invention, the alkyl group includes straight chain alkyl groups such as a methyl group, ethyl group, propyl group, butyl group, hexyl group, octyl group, decyl group, lauryl group, hexadecyl group, and a stearyl group, or branched chain alkyl groups such as an isopropyl group and an isobutyl group; the cycloalkyl group includes a cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group, and a cycloheptyl group; the aryl group includes a phenyl group and a naphthyl group; the substituted aryl group includes a benzyl group, phenethyl group, p-methylphenyl group and a o-methylphenyl group; the alkoxycarbonyl group includes a methoxycarbonyl group and an ethoxycarbonyl group; the lower alkyl group includes a methyl group, ethyl group and a propyl group; and the lower alkanoyl group includes a formyl group, acetyl group, propionyl group and a butyryl group.
Practical examples of the substituent having the formula (III): ##STR8## which is a part of the chemical structures represented by the formulas (I) and (II) are preferably a piperidino group, morpholino group, piperazino group, pyrrolidino group, 4-methylpiperazino group, 4-benzylpiperazino group, 4-diphenylmethanepiperazino group, prolyl group, nipecotinyl group and an isonipecotinyl group.
The method for preparing the compound of this invention will hereinafter be described.
Those known compounds among the compounds of this invention can be prepared by conventional methods. They are referred to as compound numbers 1-83 below. The desired compound of this invention can be readily prepared using conveniently available reactants such as dopamine, epinine and dihydrocaffic acid, and conducting chemical treatments such as the usual alkylation, acylation, esterification and conversion to amide (hereinafter as amidation). Novel compounds are prepared by the following methods.
In the first method, easily available dihydrocaffic acid ethyl ester is condensed by heating with the corresponding amine. The heating range is from room temperature to 200° C., and in many cases, the reaction can proceed without a solvent. The reaction may be carried out, if necessary, by using the corresponding amine in excess or in inert solvents such as toluene and xylene.
In the second method, easily available dihydrocaffeic acid is converted to the diacetyl derivative by a normal method using acetic anhydride or acetyl chloride, and further reacted with thionyl chloride. The corresponding acid chloride thus obtained is then reacted with the corresponding amine in the presence of a base. The base which may be used is an organic base such as pyridine and triethylamine, an inorganic base such as sodium hydroxide and potassium hydroxide, or the corresponding amine which is present in excess. The preferred reaction temperature is in the range of 0°-50° C. The preferred solvents are the above organic base, water or organic solvents such as chloroform, tetrahydrofuran and benzene.
The effects of the various compounds of this invention as the preventive and therapeutic treatments for regressive disorders of the central nervous system were assessed by the following test. A mouse fibroblast cell line, L-M cells (ATCC, CCLI, 2) was used which was described in Y. Furukawa et al., J. Biol. Chem., 261, 6039 (1986). Concentration of NGF produced and secreted in the presence of the compound of this invention was measured by the highly sensitive ELISA method. The concentration of NGF was also measured in a system using astroglial cells which were considered as a major source for the production and secretion of NGF in the central nervous system. As shown below in detail in the examples, it has been found that the compound of this invention has an extremely high ability for promoting the production and secretion of NGF. As a result, it has been confirmed that the compounds of this invention may be useful as preventive and therapeutic preparations effective for regressive disorders in the central nervous system in general and SDAT in particular.
When a compound of this invention is used as the active ingredient in preventive or therapeutic pharmaceutical composition or preparation for regressive disorders of the central nervous system, dose and formulation are naturally different depending upon the physical properties of the particular compound, symptoms of the patient and other factors. In oral administration, a suggested dose for an adult is 50-1000 mg a day and may be given as a single dose or in divided doses in the form of tablets, granules, powders, suspensions or capsules. In non-oral administration, a dose of 1-100 mg may be given as a single dose or in divided doses in the form of injections, suppositories of isotonic solutions for infusion.
For example, in preparing tablets, crystal-line cellulose, light anhydrous silicic acid and the like are used for adsorbents, and corn starch, lactose, calcium phosphate, magnesium stearate and the like are used for excipients. In preparing injections, the compound of this invention is used as an aqueous solution, an aqueous lyophobic solution in cotton seed oil, corn oil, peanut oil, olive oil etc. and also as an emulsion obtained by using surface active agents such as HCO-60 (hydrogenated caster oil, NIKKO CHEMICALS' trade name)
EXAMPLES
The present invention will hereinafter be illustrated in detail with respect to the following examples; however, these examples are not to be construed as limiting the scope of the invention.
Preparation Example 1
a) N-Acetyl-3,4-diacetoxyphenethylamine
After dissolving 2.5 g of dopamine into 10 ml of pyridine, 2.7 g of triethylamine was added to the solution. Then 8 g of acetic anhydride was added and the resultant mixture was reacted with stirring at 60°-70° C. for an hour. The reaction mixture thus obtained was poured into 200 ml of ice water, added with 50 ml of a 2.5N aqueous sodium hydroxide solution and extracted with 100 ml of chloroform. The chloroform layer was washed three times with 30 ml portions of a 2N aqueous hydrochloric acid solution, dried over anhydrous sodium sulfate. After distilling off the solvent under reduced pressure, the residue was purified by colum chromatography using silica gel. A solvent mixture of chloroform: methanol=50:1 was used as an eluent. Pure N-acetyl-3,4-diacetoxyphenethylamine was obtained as a colorless oil. The yield was 3.5 g.
NMR δ ppm (CDCl 3 ): 1.96 (S, 3H), 2.32 (S, 6H), 2.78 (t, 2H), 3.32-3.56 (m, 2H), 6.00 (br, 1H), 7.00-7.16 (m, 3H).
b) N-Acetyl-3,4-dihydroxyphenethylamine
After dissolving 1 g of N-acetyl-3,4-diacetoxyphenethylamine obtained above into 60 ml of methanol, 30 ml of water and 30 ml of a saturated aqueous sodium hydrogen carbonate solution were added under ice cooling and stirred at room temperature for 12 hours. Then a 3N aqueous hydrochloric acid solution was added dropwise under ice cooling to make the reaction mixture weakly acidic. The resultant solution was extracted four times with 50 ml of chloroform. The aqueous layer was further extracted three times with 40 ml of ethyl acetate. Both extracted solutions were dried and the solvents were distilled off. Both residues were combined and purified by column chromatography using silica gel. A mixture of chloroform:methanol=20:1 was used as an eluent. The yield of pure N-acetyl-3,4-dihydroxyphenethylamine was 0.3 g.
NMR δ ppm (DMSO-d 6 ): 1.78 (S, 3H), 2.30-2.60 (m, 2H), 2.90-3.24 (m, 2H), 6.30-6.68 (m, 3H), 7.76 (t, 1H), 8.50 (br, 2H).
Preparation Example 2
N-Ethyl-3,4-dihydroxyphenethylamine hydrobromide
After dissolving 5 g of homoveratrylamine in 20 ml of pyridine, 5.6 g of acetic anhydride was added and reacted at 65°-70° C. with stirring for 2 hours. The reaction mixture was poured into 150 ml of ice water and then made weakly acidic by adding 50 ml of a 6N aqueous hydrochloric acid solution. The resultant solution was extracted three times with 50 ml of chloroform. The extracted solution was combined, washed with an aqueous sodium hydrogen carbonate solution and dried over anhydrous sodium sulfate. The solvent was distilled off under reduced pressure. Ether was added to the residue and precipitated crystals were filtered. N-acetylhomoveratrylamine having a melting point of 101°-102° C. was obtained as colorless crystals. The yield was 5.7 g.
To a suspension of 0.98 g of lithium aluminum hydride in 50 ml of dried tetrahydrofuran (THF), a solution of 3 g of N-acetylhomoveratrylamin in 25 ml of THF was added dropwise with stirring. After heating for 3 hours under reflux, the reaction mixture was cooled with ice and gradually added dropwise under violent stirring with a solvent mixture composed of 10 ml of water and 10 ml of THF. Insoluble matter was filtered off and the filtrate was concentrated. The residue obtained was dissolved in 50 ml of ethyl acetate, washed twice with water and dried over anhydrous sodium sulfate. After distilling off the solvent under reduced pressure, N-ethyl-homoveratrylamine was obtained as oily product. The yield was 2.3 g.
After dissolving 1.0 g of N-ethyl-homoveratrylamine in a solvent mixture consisting of 6 ml of a 48% aqueous hydrogen bromide solution and 4 ml of acetic acid, the solution was heated at 120°-130° C. with stirring for 5 hours. The solvent was distilled off and the residue was crystallized from ether to obtain 1.2 g of crude crystals. N-Ethyl-3,4-dihydroxyphenethylamine hydrobromide having a melting point of 149°-151° C. was obtained by recrystallizing from isopropyl alcohol. The yield was 0.68 g.
NMR δ ppm (DMSO-d 6 ): 1.20 (t, 3H), 2.60-3.20 (m, 6H), 6.40-6.80 (m, 3H), 8.50 (m, 4H).
Preparation Example 3
Ethyl 3,4-diacetoxyphenylpropionate (compound No. 47)
a) To a solution of 18.2 g of dihydroxycaffeic acid in 200 ml of ethanol, 1 ml of concentrated sulfuric acid was added. After heating under reflux for 3 hours, ethanol was distilled off under reduced pressure. The residue was dissolved in 100 ml of ethyl acetate, washed with an aqueous sodium hydrogen carbonate solution and then with water, and dried over anhydrous sodium sulfate. After distilling off ethyl acetate under reduced pressure, ethyl 3,4-diacetoxyphenylpropionate having a melting point of 46°-47° C. was obtained. The yield was 19.8 g.
b) To a solution of 2.1 g of ethyl 3,4-diacetoxyphenylpropionate in 10 ml of pyridine, 4.2 g of acetic anhydride was added dropwise. The mixture was heated at 65°-70° C. with stirring for an hour, poured into 100 ml of ice water, neutralized with a 6N aqueous hydrogen chloride solution and extracted with 50 ml of chloroform. The extracted solution was washed with water and dried over anhydrous sodium sulfate. Chloroform was distilled off under reduced pressure. Ethyl 3,4-diacetoxyphenylpropionate was obtained as oily product. The yield was 2.3 g.
NMR δ ppm (CDCl 3 ): 1.24 (t, 3H), 2.28 (S, 6H), 2.60 (t, 2H), 3.9 (t, 2H), 4.10 (q, 2H), 6.98-7.08 (m, 3H).
Preparation Example 4
N-Methyl-3,4-dihydroxyphenylpropionamide (Compound No. 59)
A mixture of 2 g of ethyl 3,4-diacetoxyphenylpropionate and 2.1 g of a 40% aqueous methylamine solution was heated to 150° C. with stirring for 2 hours in an autoclave. After cooling, the reaction mixture was acidified, extracted three times with 25 ml of ethyl acetate and dried over anhydrous sodium sulfate. After distilling off the solvent under reduced pressure, the residue was purified by column chromatography using silica gel. A solvent mixture of chloroform:methanol=20:1 was used as eluent. Pure N-methyl-3,4-dihydroxyphenylpropionamide thus obtained was 0.35 g.
Melting Point: 117°-118° C.
IR νcm -1 (KBr): 1620, 1600, 1520, 1300, 1270.
NMR δ ppm (DMSO-d 6 ): 2.1-2.4 (m, 2H), 2.4-2.8 (m, 5H), 6.1-6.6 (m, 3H), 7.56 (br, 1H), 8.44 (br, 2H).
EXAMPLE 1
N-n-Butyl-3,4-dihydroxyphenylpropionamide (Compound No. 84)
A mixture of 5 g of ethyl 3,4-diacetoxyphenylpropionate and 3.5 g of n-butylamine was heated to 150° C. with stirring for 2 hours in an autoclave. After cooling, the reaction mixture was concentrated and the residue was purified by silica gel chromatography. A solvent mixture of chloroform:methanol=20:1 was used as eluent. Pure N-n-butyl-3,4-dihydroxyphenylpropionamide was obtained as colorless viscous oil. The yield was 5.45 g.
NMR δ ppm (DMSO-d 6 ): 0.88 (t, 3H), 1.00-1.60 (m, 4H), 2.20-2.40 (m, 2H), 2.40-2.80 (m, 2H), 2.80-3.20 (m, 2H), 6.30-6.70 (m, 3H), 7.58 (t, 1H), 8.38 (s, 1H), 8.50 (s, 1H).
EXAMPLE 2
N-n-Butyl-3,4-diacetoxyphenylpropionamide (Compound No. 85)
To a solution of 2.0 g of N-n-butyl-3,4-dihydroxyphenylpropionamide in 10 ml of pyridine, 3.4 g of acetic anhydride was added dropwise and heated to 65°-70° C. with stirring for an hour. The reaction mixture was poured into 100 ml of ice water, neutralized with 25 ml of 6N hydrochloric acid and extracted three times with 50 ml of chloroform. The extracted solution was washed with a saturated aqueous sodium hydrogen carbonate solution and dried over anhydrous sodium sulfate. The solvent was distilled off under reduced pressure. Hexane was added to the residue. The separated crystals were filtered. N-n-Butyl-3,4-diacetoxyphenylpropionamide thus obtained was 2.3 g.
Melting Point: 71°-73° C.
NMR δ ppm (CDCl 3 ): 0.88 (t, 3H), 1.00-1.60 (m, 4H), 2.24 (s, 6H), 2.20 2.48 (m, 2H), 2.70-3.28 (m, 4H), 5.60 (br, 1H), 7.00 (m, 3H).
EXAMPLE 3
N-n-Pentyl-3,4-dihydroxyphenylpropionamide
(Compound No. 86)
Ethyl 3,4-diacetoxyphenylpropionate and n-pentylamine were used in the procedure described in Example 1, to obtain N-n-pentyl-3,4-dihydroxyphenylpropionamide as an oily product.
NMR δ ppm (CDCl 3 ): 0.70-1.00 (m, 3H), 1.00-1.60 (m, 6H), 2.30-2.60 (m, 2H), 2.60-3.00 (m, 2H), 3.00-3 30 (m, 2H), 5.70 (br, 1H), 6.40-6.90 (m, 3H), 6.00-8.00 (br, 2H).
EXAMPLE 4
N-n-Hexyl-3,4-dihydroxyphenylpropionamide
(Compound No. 87)
Ethyl 3,4-diacetoxyphenylpropionate and n-hexylamine were used to obtain N-n-Hexyl-3,4-dihydroxyphenylpropionamide by carrying out the same procedures as described in Example 1.
Melting point: 69°-70° C.
NMR δ ppm (DMSO-d 6 ): 0.80-1.00 (m, 3H), 1.26 (s, 10H), 2.16-2.48 (m, 2H), 2.80-3.20 (m, 2H), 6.36-6.70 (m, 3H), 7.64-7.84 (m, 1H), 8.60 (br, 2H).
EXAMPLE 5
N-n-Hexyl-3,4-diacetoxyphenylpropionamide
(Compound No. 88)
N-n-Hexyl-3,4-dihydroxyphenylpropionamide was used to obtain N-n-Hexyl-3,4-diacetoxyphenylpropionamide by carrying out the same procedures as described in Example 2.
Melting point: 70°-72° C.
NMR δ ppm (CDCl 3 ): 0.80-1.00 (m, 3H), 1.00-1.60 (m, 10H), 2.26 (s, 6H), 2.80-3.30 (m, 4H), 5.70 (br, 1H), 7.00-7.20 (m, 3H).
EXAMPLE 6
N-Lauryl-3,4-dihydroxyphenylpropionamide
(Compound No. 89)
Ethyl 3,4-diacetoxyphenylpropionate and laurylamine were used to obtain N-Lauryl-3,4-dihydroxyphenylpropionamide by carrying out the same procedures as described in Example 1.
Melting point: 100°-102° C.
NMR δ ppm (DMSO-d 6 ): 0.80-1.00 (m, 3H), 1.24 (s, 22H), 2.20-2.48 (m, 2H), 2.90-3.20 (m, 2H), 6.40-6.76 (m, 3H), 7.72 (br, 1H), 8.40-8.80 (m, 2H).
EXAMPLE 7
N-n-Butyl-N-methyl-3,4-dihydroxyphenylpropionamide
(Compound No. 90)
Ethyl 3,4-diacetoxyphenylpropionate and N-methyl-n-butylamine were used to obtain N-n-Butyl-N-methyl-3,4-dihydroxyphenylpropionamide by carrying out the same procedures as described in Example 1.
Melting point: 96°-98° C.
NMR δ ppm (CDCl 3 ): 0.38-0.80 (m, 3H), 0.80-1.40 (m, 4H), 2.03-2.53 (m, 4H), 2.53-2.80 (m, 3H), 2.80-3.33 (m, 2H), 6.06-6.70 (m, 3H), 6.70-7.53 (br, 2H).
EXAMPLE 8
N-Stearyl-3,4-dihydroxyphenylpropionamide
(Compound No. 91)
Ethyl 3,4-diacetoxyphenylpropionate and stearylamine were used to obtain N-Stearyl-3,4-dihydroxyphenylpropionamide by carrying out the same procedures as described in Example 1.
Melting point: 100°-102° C.
NMR δ ppm (DMSO-d 6 ): 0.80-1.00 (m, 3H), 1.24 (s, 30H), 2.10-2.40 (m, 4H), 2.40-2.60 (m, 2H), 2.80-3.10 (m, 2H), 6.30-6.68 (m, 3H), 7.70 (br, 1H), 8.50 (s, 1H), 8.70 (s, 1H).
EXAMPLE 9
N,N-Di-n-hexyl-3,4-dihydroxyphenylpropionamide
(Compound No. 92)
Ethyl 3,4-diacetoxyphenylpropionate and di-n-hexylamine were used to obtain N,N-Di-n-hexyl-3,4-dihydroxyphenylpropionamide by carrying out the same procedures as described in Example 1, as an oily product.
NMR δ ppm (CDCl 3 ): 0.60-1.00 (m, 6H), 1.00-1.60 (m, 16H), 2.40-3.00 (m, 4H), 3.00-3.40 (m, 4H), 6.10-7.00 (m, 5H).
EXAMPLE 10
N-Cyclohexyl-3,4-dihydroxyphenylpropionamide
(Compound No. 93)
Ethyl 3,4-diacetoxyphenylpropionate and cyclohexylamine were used to obtain N-Cyclohexyl-3,4-dihydroxyphenylpropionamide by carrying out the same procedures as described in Example 1 as an fatty product.
NMR δ ppm (CDCl 3 ): 0.10-2.00 (m, 11H), 2.20-2.60 (m, 2H), 2.60-2.90 (m, 2H), 5.40-5.60 (m, 1H), 6.00-7.00 (m, 3H), 8.10 (br, 1H).
EXAMPLE 11
N-Methyl N-benzyl-3,4-dihydroxyphenylpropionamide
(Compound No. 94)
Ethyl 3,4-diacetoxyphenylpropionate and N-methylbenzylamine were used to obtain N-Methyl-N-benzyl-3,4-dihydroxyphenylpropionamide by carrying out the same procedures as described in Example 1.
Melting point: 107°-109° C.
NMR δ ppm (CDCl 3 ): 2.40-3.00 (m, 7H), 4.50 (s, 2H), 6.40-7.80 (m, 10H).
EXAMPLE 12
N-Phenyl-3,4-dihydroxyphenylpropionamide
(Compound No. 95)
Ethyl 3,4-diacetoxyphenylpropionate and aniline were used to obtain N-Phenyl-3,4-dihydroxyphenylpropionamide by carrying out the same procedures as described in Example 1 as an oily product.
NMR δ ppm (DMSO-d 6 ): 2.40-2.90 (m, 4H), 6.30-6.80 (m, 3H), 6.80-7.70 (m, 5H), 8.50 (br, 2H), 9.76 (s, 1H).
EXAMPLE 13
N-Adamantyl-3,4-dihydroxyphenylpropionamide
(Compound No. 96)
Ethyl 3,4-diacetoxyphenylpropionate and 1-aminoadamantane were used to obtain N-Adamantyl-3,4-dihydroxyphenylpropionamide by carrying out the same procedures as described in Example 1.
Melting point: 213°-215° C.
NMR δ ppm (DMSO-d 6 ): 1.60 (m, 6H), 1.80-2.10 (m, 8H), 2.10-2.30 (m, 2H), 2.40-2.70 (m, 3H), 6.30-6.60 (m, 3H), 8.40-8.80 (br, 2H).
EXAMPLE 14
N-[3-(3,4-Dihydroxyphenyl)propionyl]piperidine
(Compound No. 97)
A mixture of 4.2 g of ethyl 3,4-diacetoxyphenylpropionate and 2.6 g of piperidine was heated to 150° C. with stirring for 4 hours in an autoclave. After cooling, the reaction mixture was concentrated. The residue was purified by column chromatography using silica gel. A solvent mixture of chloroform:methanol=10:1 was used as eluent. The corresponding fraction was concentrated. The resultant residue was crystallized from a solvent mixture of hexane and ether. The separated crystals were filtered. Pure N-[3-(3,4-Dihydroxyphenyl)propionyl]piperidine was obtained as colorless crystals. The yield was calculated as 4.3 g.
Melting point: 114°-115° C.
NMR δ ppm (DMSO-d 6 ): 1.2-1.6 (br, 6H), 2.3-2.7 (m, 4H), 3.2-3.5 (m, 4H), 6.25-6.55 (m, 3H), 8.5 (br, 2H).
EXAMPLE 15
N-[3-(3,4-Dihydroxyphenyl)propionyl]pyrrolidine
(Compound No. 98)
Ethyl 3,4-diacetoxyphenylpropionate and pyrrolidine were used to obtain N-[3-(3,4-Dihydroxyphenyl)propionyl]pyrrolidine by carrying out the same procedures as described in Example 14.
Melting point: 172°-173° C.
NMR δ ppm (DMSO-d 6 ): 1.50-2.00 (m, 4H), 2.20-2.80 (m, 4H), 3.10-3.40 (m, 4H), 6.30-6.70 (m, 3H), 8.50 (br, 1H).
EXAMPLE 16
N-[3-(3,4-Dihydroxyphenyl)propionyl]morpholine
(Compound No. 99)
Ethyl 3,4-diacetoxyphenylpropionate and morpholine were used to obtain N-[3-(3,4-Dihydroxyphenyl)propionyl]morpholine by carrying out the same procedures as described in Example 14.
Melting point: 211°-213° C.
NMR δ ppm (DMSO-d 6 ): 2.4-2.7 (m, 4H), 3.2-3.6 (m, 8H), 6.25-6.60 (m, 3H), 8.40 (s, 1H), 8.48 (s, 1H).
EXAMPLE 17
N-Methyl-N'-[3-(3,4-dihydroxyphenyl)propionyl]piperazine
(Compound No. 100)
3,4-Dihydroxyphenylpropionic acid ethyl ester and N-methylpiperazine were used to obtain N-Methyl-N'-[3-(3,4-dihydroxyphenyl)propionyl]piperazine by carrying out the same procedures as described in Example 14.
Melting point: 190°-193° C.
NMR δ ppm (DMSO-d 6 ): 2.00-2.40 (m, 7H), 2.40-2.80 (m, 3H), 3.20-3.60 (m, 5H), 6.40-6.70 (m, 3H), 8.60 (br, 2H).
EXAMPLE 18
N-Benzyl-N'-[3-(3,4-dihydroxyphenyl)propionyl]piperazine
(Compound No. 101)
Ethyl 3,4-diacetoxyphenylpropionate and N-benzylpiperazine were used to obtain N-Benzyl-N'-[3-(3,4-dihydroxyphenyl)propionyl]piperazine by carrying out the same procedures as described in Example 14.
Melting point: 178°-180° C.
NMR δ ppm (DMSO-d 6 ): 2.20-2.40 (m, 4H), 2.40-2.70 (m, 4H), 3.20-3.60 (m, 6H), 6.30-6.80 (m, 3H), 7.20-7.56 (m, 4H), 8.56 (s, 2H).
EXAMPLE 19
N-Diphenylmethyl-N'-[3-(3,4-dihydroxyphenyl)propionyl]piperazine
(Compound No. 102)
Ethyl 3,4-diacetoxyphenylpropionate and N-diphenylmethylpiperazine were used to obtain N-Diphenylmethyl-N'-[3-(3,4-dihydroxyphenyl)propionyl]piperazine by carrying out the same procedures as described in Example 14.
Melting point: 163°-164° C.
NMR δ ppm (CDCl 3 ): 2.00-3.00 (m, 8H), 3.10-3.70 (m, 4H), 4.12 (s, 1H), 6.00-7.60 (m, 13H).
EXAMPLE 20
N-[3-(3,4-dihydroxyphenyl)propionyl]-L-proline methyl ester
(Compound No. 103)
(1) To a solution of 2 g of 3,4-diacetylphenylpropionic acid in 10 ml of chloroform, 8.9 g of thionyl chloride was added and heated to 50° C. with stirring for 2 hours. The solvent was distilled off under reduced pressure. The residue thus obtained was crude 3,4-diacetylphenylpropionyl chloride. The yield was 2.1 g. The crude propionyl chloride was used for the next reaction without further purification.
(2) To a suspension of 1.49 g of L-proline methyl ester in 15 ml of chloroform, 3 g of triethylamine was added dropwise. The propionyl chloride obtained in (1) was dissolved in 7 ml of chloroform and added dropwise to the above mixture under ice cooling. The resultant mixture was allowed to stand overnight and heated to 50° C. with stirring for an hour. After cooling, the reaction mixture was poured into 10 ml of ice water. The chloroform layer was separated, washed twice with 25 ml of one N hydrochloric acid and further washed once with an aqueous sodium chloride solution. The resultant chlororform solution was dried over anhydrous sodium sulfate and concentrated. The residue was purified by column chromatography using silica gel. A solvent mixture of chloroform:methanol=50:1 was used as eluent. N-[3-(3,4-Dihydroxyphenyl)propionyl]-L-proline methyl ester was obtained as colorless oily product. The yield was 1.25 g.
NMR δ ppm (CDCl 3 ): 1.60-2.40 (m, 4H), 2.12 (s, 3H), 2.30 (s, 3H), 2.40-3.10 (m, 4H), 3.72 (s, 3H), 3.20-3.90 (m, 2H), 4.32-4.50 (m, 1H), 6.60-7.20 (m, 3H).
(3) To a solution of 1.0 g of N-[3-(3,4-diacetoxyphenyl)propionyl]-L-proline methyl ester in 5 ml of methanol, 10 ml of a 5% aqueous ammonia solution was added under ice cooling, and stirred for an hour. The reaction mixture was then acidified with 6N hydrochloric acid under ice cooling and extracted twice with chloroform. The chloroform solution was dried over anhydrous sodium sulfate. N-[3-(3,4-diacetoxyphenyl)propionyl]-L-proline methyl ester was obtained after distilling off chloroform as a colorless oily product. The yield was 0.7 g.
NMR δ ppm (CDCl 3 ): 1.60-2.30 (m, 4H), 2.30-3.00 (m, 4H), 3.00-3.60 (m, 2H), 3.64 (s, 3H), 4.40-4.60 (m, 1H), 6.40-6.80 (m, 3H), 6.90 (br, 1H), 7.60 (br, 1H).
EXAMPLE 21
Ethyl N-[3-(3,4-dihydroxyphenyl)propionyl]nipecotinate
(Compound No. 104)
The same procedures as described in Example 20 were carried out except that nipecotic acid ethyl ester hydrochloride was used in place of L-proline methyl ester hydrochloride.
Thus N-[3-(3,4-dihydroxyphenyl)propionyl]nipecotic acid ethyl ester was obtained as a colorless oily product.
NMR δ ppm (CDCl 3 ): 1.20-1.48 (m, 3H), 1.46-2.40 (m, 5H), 2.40-3.54 (m, 6H), 3.54-4.68 (m, 4H), 6.50-7.20 (m, 4H), 7.66 (br, 1H).
EXAMPLE 22
Acute toxicity
A group of male ddy 10 mice 5-weeks old was used for the acute toxicity test. The test sample was prepared by suspending the test compound in 0.5% aqueous Tween 80. The test compound was administered by intraperitoneal injection. Numbers of deaths were counted after one and four days, and an LD 50 value was calculated from these numbers.
None of the compounds tested had a LD 50 value of at least 1000 mg/kg. That is, acute toxicity was extremely low.
EXAMPLE 23
Promoting activity for the production and secretion of NGF in mouse L-M cells
This experiment was performed according to the procedures of Y. Furukawa et al. which is described in J. Biol. Chem., 261, 6039-6047 (1986).
Mouse L-M cells were precultured in Medium 199 (a product of Gibco Co.) supplemented with 0.5% peptone, and then innoculated in a 24-well cultivation plate having a well surface area of 2.1 cm 2 (a product of Falcon Co.) at a cell density of about 3×10 4 cells/well. The medium was cultured for 3 days at a temperature of 37° C. After completing the confluency (about 10 6 cells/well), the medium was changed to Medium 199 (0.5 ml/well) containing 0.5% bovine serum albumin (Fraction V, a product of Armour Co.). The sample of the derivative tested is contained in the medium at a prescribed concentration as illustrated in the Tables. NGF concentration in the medium after cultivating for 24 hours was determined according to high sensitivity ELISA [S. Furukawa et al., J. Nuurochem., 40, 734-744 (1983)]. Data are expressed as fold increase in NGF content of the medium over that cultivated in the absence of the derivative to be tested. The lower detection limit of ELISA is 0.25 pg/ml and the NGF content of control medium is normally 50-200 pg/0.5 ml/well. Data are presented as the mean of four determinations. The results are illustrated in Tables 1-5.
EXAMPLE 24
Promoting activity for the production and secretion of NGF in mouse brain astroglial cells
The experiment was performed by inducing astroglial cells from the mouse forebrain to a culture system according to the procedures of S. Furukawa et al. which is described in Biochem. Biophys. Res. Commun., 136, 57-63 (1986).
Forebrains of 8-days old mice were dissected out and cut into small pieces. The pieces were washed with calcium- and magnesium-free phosphate-buffered saline (hereinafter abbreviated as PBS), treated with 0.25% trypsin containing PBS at 37° C. for 30 minutes and triturated with a Pasteur pipet to give a suspension. Cells and cell clumps were recovered by centrifugation at 200 xg for 5 minutes. They were cultured in Dulbecco modified Eagle's medium (a product of Gibco Co. hereinafter abbreviated as DMEM) containing 10% fetal calf serum, 50 μ units/ml of penicillin, and 50 μg/ml of streptomycin, for 10 to 14 days with medium changes every 3 days. After completing confluency, the cells were dissociated by trypsin treatment and recultured in new culture flasks. This procedure was repeated further twice and more. The culture became a uniform cell cluster. The cell cluster for use in this invention can be stained not less than 97% in accordance with the PAP staining method (peroxidase/antioxidase staining method) using anti-human glial fibrillar acidic protein (GFAP) rabbit antiserum. The cells will hereinafter be referred to as astroglial cells.
Astroglial cells were innoculated in 24-well plates having a well surface area of 2.1 cm 2 (a product of Falcon Co.) at a cell density of about 3×10 4 cells/well and cultured for 3 days in DMEM medium supplemented with 10% of fetal calf serum. After completing confluency about (10 7 cells/well), the medium was changed to DMEM medium (0.5 ml/well) supplemented with 0.5% of bovine serum albumin (fraction V) and cultured for 3 days. The culture was further continued with medium changes every 3 days. After cells were practically synchronized in the quiscent stage, the medium was changed to 0.5 ml of the same medium and containing a prescribed concentration of test sample as illustrated in the Tables. NGF in the medium after cultivating for 24 hours was determined by the ELISA as mentioned above. Data are expressed as fold increase in NGF content over that in the absence of the test sample. The lower detection limit of the ELISA is 0.25 pg/ml and the NGF content of control medium was normally 1-10 pg/0.5 ml/well. Data are presented as the mean of four determinations. The results are illustrated in Tables 1-5.
TABLE 1__________________________________________________________________________Promoting activity of compound having the following formula for theproduction andsecretion of NGF in mouse L-M cells. ##STR9##- Sample NGF NGFCompound Substituent Concentration Concentration IncreaseNo. R.sub.1 R.sub.7 R.sub.8 n (mM) (ng/well) Ratio__________________________________________________________________________ Control 0 0.33 1.00 1 H COCH.sub.3 H 2 0.2 3.05 9.24 2 H COCH.sub.2 CH.sub.3 H 2 0.2 3.10 9.39 3 H COCH.sub.2 CH.sub.2 CH.sub.3 H 2 0.2 3.18 9.64 4 H COCH.sub.3 H 1 0.2 2.60 7.88 5 H COCH.sub.2 CH.sub.3 H 1 0.2 2.75 8.33 6 H COCH.sub.2 CH.sub.2 CH.sub.3 H 1 0.2 2.95 8.94 7 H COCH.sub.3 H 3 0.2 2.81 8.52 8 H COCH.sub.2 CH.sub.3 H 3 0.2 2.90 8.79 9 H COCH.sub.2 CH.sub.2 CH.sub.3 H 3 0.2 2.75 8.3310 H COCH.sub.3 CH.sub.3 2 0.2 3.20 9.7011 H COCH.sub.2 CH.sub.3 CH.sub.3 2 0.2 3.32 10.0612 H COCH.sub.2 CH.sub.2 CH.sub.3 CH.sub.3 2 0.2 3.02 9.1513 COCH.sub.3 COCH.sub.3 H 2 0.2 4.03 12.2114 COCH.sub.3 COCH.sub.2 CH.sub.3 H 2 0.2 3.49 10.5815 COCH.sub.3 COCH.sub.2 CH.sub.2 CH.sub.3 H 2 0.2 2.95 8.9416 COCH.sub.3 COCH.sub.3 H 1 0.2 2.72 8.2417 COCH.sub.3 COCH.sub.3 H 3 0.2 2.85 8.6418 COCH.sub.3 COCH.sub.3 CH.sub.3 2 0.2 3.95 11.9719 H CH.sub.2 CH.sub.3 H 2 0.2 3.50 10.6120 H CH.sub.2 CH.sub.2 CH.sub.3 H 2 0.2 3.62 10.9721 H CH.sub.2 CH.sub.2 CH.sub.2 CH.sub.3 H 2 0.2 3.80 11.5222 H CH.sub.3 H 1 0.2 2.97 9.0023 H CH.sub.2 CH.sub.3 H 1 0.2 3.08 9.3324 H CH.sub.2 CH.sub.2 CH.sub.3 H 1 0.2 2.94 8.9125 H CH.sub.2 CH.sub.2 CH.sub.2 CH.sub.3 H 1 0.2 2.91 8.8226 H CH.sub.3 H 3 0.2 2.84 8.6127 H CH.sub.2 CH.sub.3 H 3 0.2 2.89 8.7628 H CH.sub.2 CH.sub.2 CH.sub.3 H 3 0.2 2.79 8.4529 H CH.sub.2 CH.sub.2 CH.sub.2 CH.sub.3 H 3 0.2 2.88 8.7330 COCH.sub.3 CH.sub.3 CH.sub.3 2 0.2 3.80 11.5231 COCH.sub.3 CH.sub.2 CH.sub.3 CH.sub.3 2 0.2 3.76 11.39 Comparative ExampleComparative H H H 2 0.2 1.30 3.94compound__________________________________________________________________________
TABLE 2__________________________________________________________________________Promoting activity of compound having the following formula for theproduction andsecretion of NGF in mouse L-M cells. ##STR10## Sample NGF NGFCompound Substituent Concentration Concentration IncreaseNo. R.sub.1 R.sub.6 n (mM) (ng/well) Ratio__________________________________________________________________________Control 0 0.34 1.0034 H COOCH.sub.3 2 0.2 1.97 5.7935 H COOCH.sub.2 CH.sub.3 2 0.2 1.98 5.8236 H COOCH.sub.2 CH.sub.2 CH.sub.3 2 0.2 1.88 5.5337 H COOCH.sub.2 CH.sub.2 CH.sub.2 CH.sub.3 2 0.2 1.85 5.4438 H COOCH.sub.3 1 0.2 1.63 4.7939 H COOCH.sub.2 CH.sub.3 1 0.2 1.78 5.2440 H COOCH.sub.2 CH.sub.2 CH.sub.3 1 0.2 1.84 5.4141 H COOCH.sub.2 CH.sub.2 CH.sub.2 CH.sub.3 1 0.2 1.79 5.2642 H COOCH.sub.3 3 0.2 1.81 5.3243 H COOCH.sub.2 CH.sub.3 3 0.2 1.88 5.5344 H COOCH.sub.2 CH.sub.2 CH.sub.3 3 0.2 1.91 5.6245 H COOCH.sub.2 CH.sub.2 CH.sub.2 CH.sub.3 3 0.2 1.84 5.4146 CH.sub.3 CO COOCH.sub.3 2 0.2 2.01 5.9147 CH.sub.3 CO COOCH.sub.2 CH.sub.3 2 0.2 2.14 6.2948 CH.sub.3 CO COOCH.sub.2 CH.sub.2 CH.sub.3 2 0.2 2.13 6.2649 CH.sub.3 CO COOCH.sub.2 CH.sub.2 CH.sub.2 CH.sub.3 2 0.2 2.14 6.2950 CH.sub.3 CO COOCH.sub.3 1 0.2 1.73 5.0951 CH.sub.3 CO COOCH.sub.2 CH.sub.3 1 0.2 1.98 5.8252 CH.sub.3 CO COOCH.sub.2 CH.sub.2 CH.sub.3 1 0.2 1.88 5.5353 CH.sub.3 CO COOCH.sub.2 CH.sub.2 CH.sub.2 CH.sub.3 1 0.2 1.63 4.7954 CH.sub.3 CO COOCH.sub.3 3 0.2 1.88 5.5355 CH.sub.3 CO COOCH.sub.2 CH.sub.3 3 0.2 1.98 5.8256 CH.sub.3 CO COOCH.sub.2 CH.sub.2 CH.sub. 3 3 0.2 1.73 5.0957 CH.sub.3 CO COOCH.sub.2 CH.sub.2 CH.sub.2 CH.sub.3 3 0.2 1.81 5.3258 H CONH.sub.2 2 0.2 1.88 5.5359 H CONHCH.sub.3 2 0.2 1.91 5.6260 H CONHCH.sub.2 CH.sub.3 2 0.2 1.84 5.4161 H CONHCH.sub.2 CH.sub.2 CH.sub.3 2 0.2 2.01 5.9162 H CONH.sub.2 1 0.2 1.63 4.7963 H CONHCH.sub.3 1 0.2 1.98 5.8264 H CONHCH.sub.2 CH.sub.3 1 0.2 1.81 5.3265 H CONHCH.sub.2 CH.sub.2 CH.sub.3 1 0.2 1.77 5.2166 H CONHCH.sub.2 CH.sub.2 CH.sub.2 CH.sub.3 1 0.2 1.99 5.8567 H CONH.sub.2 3 0.2 1.69 4.9768 H CONHCH.sub.3 3 0.2 1.73 5.0969 H CONHCH.sub.2 CH.sub.3 3 0.2 1.88 5.5370 H CONHCH.sub.2 CH.sub.2 CH.sub.3 3 0.2 1.83 5.3871 H CONHCH.sub.2 CH.sub.2 CH.sub.2 CH.sub.3 3 0.2 1.83 5.7172 H CON(CH.sub.3).sub.2 2 0.2 1.94 5.9173 CH.sub.3 CO CONH.sub.2 2 0.2 2.01 5.6874 CH.sub.3 CO CONHCH.sub.2 CH.sub.3 2 0.2 1.93 5.8575 CH.sub.3 CO CONH.sub.2 1 0.2 2.03 5.5376 CH.sub.3 CO CONHCH.sub.2 CH.sub.3 1 0.2 1.88 5.4777 CH.sub.3 CO CONHCH.sub.2 CH.sub.2 CH.sub.2 CH.sub.3 1 0.2 1.86 5.2678 CH.sub.3 CO CONH.sub.2 3 0.2 1.79 4.9479 CH.sub.3 CO CONHCH.sub.2 CH.sub.3 3 0.2 1.82 5.3580 CH.sub.3 CO CONHCH.sub.2 CH.sub.2 CH.sub.2 CH.sub.3 3 0.2 1.95 5.7481 CH.sub.3 CO CON(CH.sub.3).sub.2 2 0.2 1.96 5.76__________________________________________________________________________
TABLE 3__________________________________________________________________________Promoting activity of compound having the following formula for theproduction andsecretion of NGF in mouse brain astroglial cells. ##STR11## Sample NGF NGFCompound Substituent Concentration Concentration IncreaseNo. R.sub.1 R.sub.7 R.sub.8 n (mM) (ng/well) Ratio__________________________________________________________________________ Control 0 42.3 1.00 1 H COCH.sub.3 H 2 0.4 208.8 4.94 3 H COCH.sub.2 CH.sub.2 CH.sub.3 H 2 0.2 155.0 3.66 7 H COCH.sub.3 H 3 0.4 188.5 4.4610 H COCH.sub.3 CH.sub.3 2 0.4 205.2 4.8512 H COCH.sub.2 CH.sub.2 CH.sub.3 CH.sub.3 2 0.4 206.7 4.8913 COCH.sub.3 COCH.sub.3 H 2 0.4 198.8 4.7015 COCH.sub.3 COCH.sub.2 CH.sub.2 CH.sub.3 H 2 0.2 158.2 3.7417 COCH.sub.3 COCH.sub.3 H 3 0.2 180.6 4.2719 H CH.sub.2 CH.sub.3 H 2 0.4 176.3 4.1721 H CH.sub.2 CH.sub.2 CH.sub.2 CH.sub.3 H 2 0.4 207.5 4.9132 H CH.sub.2 CH.sub.2 CH.sub.2 CH.sub.3 CH.sub.3 2 0.4 203.8 4.8233 COCH.sub.3 CH.sub.2 CH.sub.2 CH.sub.2 CH.sub.3 CH.sub.3 2 0.4 200.6 4.7426 H CH.sub.3 H 3 0.4 176.5 4.1729 H CH.sub.2 CH.sub.2 CH.sub.2 CH.sub.3 H 3 0.4 180.3 4.26__________________________________________________________________________
TABLE 4__________________________________________________________________________Promoting activity of compound having the following formula for theproduction andsecretion of NGF in mouse brain astroglial cells. ##STR12## Sample NGF NGFCompound Substituent Concentration Concentration IncreaseNo. R.sub.1 R.sub.6 n (mM) (ng/well) Ratio__________________________________________________________________________35 H COOCH.sub.2 CH.sub.3 2 0.2 200.1 4.6337 H COOCH.sub.2 CH.sub.2 CH.sub.2 CH.sub.3 2 0.2 208.5 4.8339 H COOCH.sub.2 CH.sub.3 1 0.2 210.1 4.8643 H COOCH.sub.2 CH.sub.3 3 0.2 198.5 4.5947 CH.sub.3 CO COOCH.sub.2 CH.sub.3 2 0.4 220.8 5.1149 CH.sub.3 CO COOCH.sub.2 CH.sub.2 CH.sub.2 CH.sub.3 2 0.4 223.7 5.1851 CH.sub.3 CO COOCH.sub.2 CH.sub.3 1 0.4 194.6 4.5055 CH.sub.3 CO COOCH.sub.2 CH.sub.3 3 0.4 189.7 4.3958 H CONH.sub.2 2 0.2 230.0 5.3260 H CONHCH.sub.2 CH.sub.3 2 0.2 300.4 6.9582 H CONHCH.sub.2 CH.sub.2 CH.sub.2 CH.sub.3 2 0.2 360.9 8.3564 H CONHCH.sub.2 CH.sub.3 1 0.2 200.8 4.6569 H CONHCH.sub.2 CH.sub.3 3 0.2 194.1 4.4972 H CON(CH.sub.3).sub.2 2 0.2 280.6 6.5074 CH.sub.3 CO CONHCH.sub.2 CH.sub.3 2 0.4 282.2 6.5373 CH.sub.3 CO CONH.sub.2 2 0.4 330.6 7.6583 CH.sub.3 CO CONHCH.sub.2 CH.sub.2 CH.sub.2 CH.sub.3 2 0.4 381.2 8.8276 CH.sub.3 CO CONHCH.sub.2 CH.sub.3 1 0.4 209.1 4.8479 CH.sub.3 CO CONHCH.sub.2 CH.sub.3 3 0.4 197.3 4.5781 CH.sub.3 CO CON(CH.sub.3).sub.2 2 0.4 273.5 6.33__________________________________________________________________________
TABLE 5__________________________________________________________________________Promoting activity of compound having the following formula for theproduction and secretion ofNGF in mouse L-M cells and brain astroglial cells. ##STR13## NGFCompound L-M Cell Astroglial CellSubstiuent Concentration Concentration Increase Concentration IncreaseNo. R.sub.1 R.sub.2 (mM) (ng/well) Ratio (ng/well) Ratio__________________________________________________________________________84 H CONH(CH.sub.2).sub.3 CH.sub.3 0.4 5.39 6.2 539.5 33.185 CH.sub.3 CO CONH(CH.sub.2).sub.3 CH.sub.3 0.4 5.92 6.8 547.7 33.686 H CONH(CH.sub.2).sub.4 CH.sub.3 0.4 5.66 6.5 493.9 30.387 H CONH(CH.sub.2).sub.5 CH.sub.3 0.4 5.05 5.8 195.6 12.088 CH.sub.3 CO CONH(CH.sub.2).sub.5 CH.sub.3 0.4 5.39 6.2 257.5 15.889 H CONH(CH.sub.2).sub.11 CH.sub.3 0.4 3.74 4.3 81.5 5.090 H ##STR14## 0.4 5.57 6.4 489.0 30.091 H CONH(CH.sub.2).sub.17 CH.sub.3 0.4 3.57 4.1 84.8 5.292 H ##STR15## 0.4 4.35 5.0 143.4 8.893 H ##STR16## 0.4 5.22 6.0 161.4 9.994 H ##STR17## 0.4 4.44 5.1 84.8 5.295 H ##STR18## 0.4 5.13 5.9 182.6 11.296 H ##STR19## 0.4 4.96 5.7 293.4 18.097 H ##STR20## 0.4 5.39 6.2 435.7 13.798 H ##STR21## 0.4 5.31 6.1 407.0 12.899 H ##STR22## 0.4 4.18 4.8 165.4 5.2100 H ##STR23## 0.4 4.35 5.0 260.8 8.2101 H ##STR24## 0.4 4.52 5.2 305.3 9.6102 H ##STR25## 0.4 4.44 5.1 321.2 10.1103 H ##STR26## 0.4 3.74 4.3 200.3 6.3104 H ##STR27## 0.4 4.96 5.7 248.0 7.8Control 0 0.87 1.00 31.8 1.00__________________________________________________________________________ (1) ph: phenyl group | Catechol derivatives which produce nerve growth factor in particular tissues of the brain are disclosed. These derivatives provide preventive and therapeutic effects for regressive disorders of the central nervous system including senile dementia of the Alzheimer type. | 2 |
FIELD OF THE INVENTION
The instant invention is directed generally to devices used by orthopedic surgeons to stabilize and align skeletal structures. More specifically, the instant invention includes a fastener capable of rotation about an axis within a supporting cup, the cup contoured to receive a rod therein and a means to fix the rod and rotationally oriented fastener in a fixed position.
BACKGROUND OF THE INVENTION
Orthopedic procedures involving stabilization of skeletal structure presently suffer from two common frailties: the first is the inability to orient the stabilizing structure for a multiplicity of common angulations and the second is the failure to provide a reliable thread portion which engages bone of the patient.
SUMMARY OF THE INVENTION
The instant invention provides the ability to address various skeletal components in a relational way by allowing articulation of the device in a multiplicity of angulations and to fasten to the skeletal structure to provide greater stabilization with an improved thread pattern which provides both axially compressive forces along the length of the fastener and radially inward drawing forces.
OBJECTS OF THE INVENTION
Accordingly, it is a primary object of the present invention to provide an orthopedic stabilization structure.
A further object of the present invention is to provide an improved threaded portion therefore.
A further object of the present invention is to accommodate a plurality of angulations when addressing a skeletal structure.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a top view of the fastener.
FIG. 2 is a side view of the fastener.
FIG. 3 is a sectional view of the fastener geometry.
FIG. 3A shows FIG. 3 with a taper.
FIG. 4 shows the fastener and stabilization structure.
FIG. 5 is another view of FIG. 4 .
FIG. 6 displays angulation of the FIG. 4 structure.
FIG. 7 details a bolt used in the structure.
FIG. 8 details the bolt receiving area.
FIG. 9 shows one side of the cup.
FIG. 10 shows an adjacent side (90 degrees) relative to FIG. 9, showing a diametrical slot.
FIG. 11 is a top view of FIGS. 9 and 10.
FIG. 12 is a bottom view of FIGS. 9 through 11.
FIG. 13 is a sectional view of FIG. 9 along lines 13 — 13 .
FIG. 14 is a sectional view similar to FIG. 4 .
FIG. 15 adds a fastener and rod to FIG. 14 .
FIG. 16 adds a fixing bolt to FIG. 15 .
FIG. 17 shows the device deployed by way of example.
DESCRIPTION OF PREFERRED EMBODIMENTS
Considering the drawings, wherein like reference numerals denote like parts throughout the various drawing figures, reference numeral 100 is directed to the orthopedic stabilization device according to the present invention.
The device 100 allows a threaded fastener 10 to move about the arrow C as shown in FIG. 4 such that although the long axis of the threaded shaft is depicted as presently aligned, it can be rotated and skewed from a vertical long axis of a cup 130 as in FIG. 6. A rotational means 120 embodied as a disc has a cylindrical outer face 122 and planar top and bottom faces 124 , 126 . Thus, rotation about the arrow C occurs about a geometrical center 128 . The disc 120 is integrally fixed to fastener 10 . The rotational means 120 is constrained within a cup 130 having a central bore 132 , an upper portion of which is provided with threads 111 . In addition, a transverse slot 134 is cut along a diameter of the cup which allows slideable insertion therein of both the fastener 10 and integral disc 120 as well as a rod 136 transverse to a long axis of the cup 130 . Please see FIGS. 9 through 16. The cup 130 is dimensioned such that the rotational means 120 is in tangential registry along one cylindrical face 122 with the rod 136 . The threaded bore 132 receives a threaded fixing bolt 110 therewithin to press the rod 136 against the rotational means 120 to fix their relative relationship once appropriate orientation has occurred.
In its essence, the fastener 10 includes a threaded shaft 32 having a first thread pattern 12 at one end and a second thread pattern 14 at an opposite end. As shown in FIGS. 1 and 2, the first end thread pattern 12 terminates in a point 16 and the threads increase in diameter to form a thread pattern with its spiral increasing as it extends away from the point 16 .
The second thread pattern 14 has a larger diameter but a similar thread contour which shall be discussed in detail infra. Preferably, the shaft 32 is of variable length and tapers and narrows from end 18 to point 16 . Please see FIGS. 1 and 2.
A further nuance of the first and second thread patterns is that the first thread pattern 12 has a coarser thread than the second thread pattern 14 which is a finer thread. The point 16 is the point of initiation for insertion into a bone during an orthopedic procedure. To facilitate same, a pilot hole may be drilled in the bone but thereafter, because of the tapering nature of the first thread 12 , this portion is thereafter self-threading. Notice that the crest 70 for both first and second thread patterns are sharp. This allows cutting into the bone which typically has a harder exterior than the interior. By providing a coarser thread pattern for the first thread 12 , this thread will insert into the bone faster than the second thread pattern 14 . As a consequence, when the bone begins to be engaged by the second thread pattern, an axial compression of the bone occurs along the direction of the two arrows A. In addition, because of the thread geometry, the threads will exert a radially inwardly directed force along the direction of the double-ended arrows B. Whereas in the prior art, conventional fasteners induced radially outwardly spreading (the opposite direction from arrow B), the instant invention provides radially inwardly or a drawing force B as well as the compressive force A.
The threads 60 of fastener 10 for threads 12 and 14 are actually one continuous helically wound thread which begins at the ends and spirals towards the medial portion of shaft 32 as it migrates from the ends. Please see FIG. 3 .
The threads 60 include a sharpened crest 70 defining a major diameter 62 of the threads and a root 80 defining a minor diameter 64 of the threads 60 . As shown in detail in FIG. 3, the threads 60 have an upper surface 66 which extends from a bottom edge 84 of the root 80 to the sharpened crest 70 . The threads 60 also include a lower surface 68 which extends from a top edge 82 of the root 80 to the sharpened crest 70 . Both the upper surface 66 and lower surface 68 angle toward the medial portion of the fastener as the surfaces 66 , 68 extend from the root 80 to the crest 70 .
In section, the surfaces 66 , 68 extend linearly from the root 80 to the sharpened crest 70 . However, as this contour is rotated helically about the threaded shaft 32 along with the threads 60 , the upper surface 66 and lower surface 68 take on a curved surface appearance. This appearance is similar to that which would be formed by a linear section of the surface of a cone with a tip of the cone oriented downward and the cone rotated and translated upward along a central axis thereof. The upper surface 66 and lower surface 68 thus have a curved surface in three dimensions similar to that of a cone, but a linear character when viewed in section.
The upper surface 66 extends from the root 80 to the sharpened crest 70 at an upper surface angle α diverging from a reference plane orthogonal to the central long axis 2 of the fastener. The upper surface angle α is preferably 20° but could be any angle between 0° and 90°. The lower surface 68 extends from the root 80 to the sharpened crest 70 at a lower surface angle β with respect to the reference plane. The lower surface angle β 0 is preferably 40° but could vary between 0° and 90°.
The upper surface angle α is preferably less than the lower surface angle β. In this way, the threads 60 are provided with greater thickness, and hence greater strength adjacent the minor diameter 64 than at the major diameter 62 and are thus more capable of bearing the loads experienced within the bone.
It is the angulation of the surfaces, especially upper surface 66 which encourages the radially inward force. When the upper and lower thread patterns are combined, axial compressive forces can be seen. Note the flat wall 54 of FIG. 3 . This could replace point 16 and require a deeper pilot hole.
The second thread portion 14 has the same FIG. 3 geometry except that the threads 60 a are inverted, and as mentioned earlier are a finer thread (greater threads per inch axially) than the first thread portion 12 . In other words FIG. 3 would be viewed upside down for threads 14 .
FIG. 3A shows a section of thread with a pronounced taper. For thread pattern 14 , FIG. 3A would be viewed upside down and with a reverse taper to that shown.
A bottom 129 of cup 130 (FIG. 4) has clearance 22 which extends within an included arc preferably approaching 90 degrees to allow a wide range of fastener 10 rotation about arrow C. Rotation beyond this clearance 22 is prevented by cup wall structure 24 that survives both the clearance aperture 22 and the slot 134 that runs diametrically down two sides of the substantially cylindrical cup 100 . Free ends 138 of the cup 100 need the support a bolt 110 (FIG. 16) to: (first) press the rod 136 in place by (second) applying pressure to the disk 120 and retaining it by (third) uniting the free ends 138 .
The threads 60 of the threaded bolt 110 (FIGS. 7 and 16) are actually one continuous helically wound thread which begins at the bottom 54 and spirals up to the top 52 . While this single thread design is preferred, other arrangements including compound series of threads which wind helically together from the bottom 54 to the top 52 could also be utilized.
The threads 60 include a crest 170 defining a major diameter 62 of the threads and root 80 defining a minor diameter 64 of the threads 60 . As shown in detail in FIG. 7, the threads 60 have an upper surface 66 which extends from a bottom edge 84 of the root 80 to the upper edge 72 of crest 170 . The threads 60 also include a lower surface 68 which extends from a top edge 82 of the root 80 to a lower edge 74 of the crest 170 . Both the upper surface 66 and lower surface 68 angle upwards as the surfaces 66 , 68 extend from the root 80 to the crest 170 . Both the crest 170 and root 80 exhibit a constant distance from the central axis 2 between the top edge 82 and the bottom edge 84 . Compared to FIG. 3, crest 170 is blunt, while crest 70 is sharpened. Also, bolt 110 and thread 111 could have sharp contours like crest 70 (replacing crest 170 ) and vice versa.
In section, the surfaces 66 , 68 extend linearly from the root 80 to the crest 170 . However, as this contour is rotated helically about the threaded bolt 110 along with the threads 60 , the upper surface 66 and lower surface 68 take on a curved surface appearance. This appearance is similar to that which would be formed by a linear section of the surface of a cone with a tip of the cone oriented downward and the cone rotated and translated upward along a central axis thereof. The upper surface 66 and lower surface 68 thus have a curved surface in three dimensions similar to that of a cone, but a linear character when viewed in section.
The upper surface 66 extends from the root 80 to the crest 170 at an upper surface angle α diverging from a reference plane 4 orthogonal to the central axis 2 . The upper surface angle α is preferably 20 degrees but could be any angle between 0 degrees and 90 degrees. The lower surface 68 extends from the root 80 to the crest 170 at a lower surface angle β with respect to the reference plane 4 . The lower surface angle β is preferably 40 degrees but could vary between 0 degrees and 90 degrees.
The upper surface angle α is preferably less than the lower surface angle β such that a thickness of the threads 60 at the crest 170 is less than a thickness of the threads 60 between adjacent roots 80 . In this way, the threads are provided with greater thickness, and hence greater strength adjacent the minor diameter 64 than at the major diameter 62 and are thus more capable of bearing the loads experienced within the threaded bore 132 .
Referring now to FIG. 8, details of the threaded bore 132 on free ends 13 are shown. The bore is preferably substantially complemental in form to the threaded shaft of the bolt 110 . The bore includes threads T. The thread geometry of the bolt 110 and threads T draw free ends 136 of cup 130 together along arrow D.
FIG. 17 shows a fractured bone and the device 100 being applied. The fasteners 10 with discs 120 and the cups 130 are located such that the fasteners 10 are located in the bone, but the disc can rotate within clearance 22 as described. Recall the threads 12 , 14 axially compress and radially inwardly drawing in the bone. Next the rod 136 is placed within the slots 134 of the cups 130 .
The rod is shown as having a bend 165 to demonstrate the system's versatility. Next the bolts 110 are threaded into threads 111 in the free ends 138 of the cups 130 . As the bolts 110 bear on rod 136 , the rod 136 , disc 120 and fastener 10 become rigid. The free ends 138 also draw together tightly.
Moreover, having thus described the invention, it should be apparent that numerous structural modifications and adaptations may be resorted to without departing from the scope and fair meaning of the instant invention as set forth hereinabove and as described hereinbelow by the claims. | An orthopedic stabilization structure including a threaded fastener capable of articulation to accommodate various skeletal geometries, a rod, and a cup supporting the threaded fastener and the rod to be subsequently helps in fixed position with respect to the skeletal structure. | 0 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to the slitting of a traveling fibrous web, particularly a paper web. More particularly, this invention relates to the slitting of a traveling paper web utilizing both a water jet and a laser. Still more particularly, this invention relates to the efficient slitting of a traveling paper web utilizing a water jet to sever the web, and a laser to cut the edges to produce a smooth edge on the severed parts.
2. Description of the Prior Art
The use of a high pressure water jet to cut a traveling web, such as paper, into strips is known in the papermaking art. Also known is the use of a laser beam to cut a fibrous web, such as paper. Both of these devices have been tried in an effort to improve the slitting results provided by a pair of cooperating rotating disks which have outer edges that rotate toward one another and intersect over the oncoming web passing therebetween to effect the cutting operation. Such disk- type slitters are well-known and represent the standard in the papermaking industry.
However, there are deficiencies and operating inefficiencies associated with the use of cooperating disks, lasers and high pressure water jets to effect the web slitting operation. In the case of cooperating disks, a great deal of dust is produced as the blades tear individual fibers from the paper web during the slitting process. In addition, disk slitters tend to produce edge cracks extending laterally in the paper being slit which, in turn, promotes lateral tearing and sheet breaks in the winding process on a papermaking machine or, even worse, during the printing process in the paper manufacturer's customer's plant. Finally, disk-type slitters require continual sharpening and/or replacement of the disks and must have transport and holder assemblies on both sides of the traveling web for each of the disks.
Perhaps the greatest deficiency in using water jets to slit a traveling paper web, especially a completely dried web, such as is the case in the winder, resides in the inherent nature of the severing process using a water jet. Specifically, the high pressure jet stream of water effects the web severance by impacting the individual paper fibers in the web. The actual severance is thus accomplished by physically pushing fillers, fines and individual fibers from the spot of jet stream impact outwardly toward the far surface and away from the web. Individual wood pulp fibers are not cut into pieces, but instead have fines, fillers and even small, or short, fibers washed away by the impact of the high pressure water jet. This leaves the ends of individual wood pulp fibers protruding from each severed edge of the web. The water jet cut results in a somewhat ragged pair of edges on either side of the slit in the web. This is both aesthetically unappealing, deleterious to subsequent processing of the paper product and generally undesirable to both the paper manufacturer and its customers.
In the case of a laser, the slit produced in the traveling web is well defined with a smooth, continuous edge from the standpoint of having few or no fiber ends protruding from the edge of the web. However, lasers powerful enough to cut a web at the speeds and calipers encountered in the paper manufacturing or winding operation tend to be relatively expensive to operate.
SUMMARY OF THE INVENTION
The deficiencies and operational inefficiencies of prior slitters have been obviated by this invention. In this invention, a high pressure water jet is used to sever the traveling paper web into two parts, or co-running strips. Operating in both physical and process cooperation with the water jet is a laser which traverses the same slit and burns away the protruding ends of the severed paper fibers in the adjacent edges of the slit strips. Thus, the water jet, which is relatively inexpensive to operate compared with a laser powerful enough to slit a web of the same caliper and traveling at the same speed, is used to sever the web while a laser having much less power than would otherwise be required to slit the web is used to burn off and trim the ends of the wood pulp fibers protruding from the severed edges of the paper strips.
A trough is positioned on the side of the web opposite the water jet and laser to receive the water and particles dislodged from the web from the impact of the water jet and burning operation of the laser. The trough can be either a small container positioned beneath the water jet and laser, and traverse the width of the web with them when they are repositioned, or it can extend for the width of the web and remain stationary. In either case, its primary purpose is to absorb the water jet energy, but it also operates to both capture fibrous particles and remove them with the collected water from the apparatus. The presence of a pool of water in the trough collected from the water jet also functions to diffuse spectral emissions from the laser and shield the laser from operating personnel. Since the water jet and laser are preferably mounted on the same side of the traveling paper web, no transport and holder assemblies are required for slitting equipment on the other side of the web which facilitates both the operation and maintenance of the apparatus.
In addition, an air jet is preferably used in conjunction with the laser to urge particles burned away from the ends of the pulp fibers downwardly and into the water trough. This is primarily to prevent dust from coming back onto the lens of the laser, which could produce a hot spot on the lens, but it also helps to decrease the amount of particles released into the atmosphere.
Neither the water jet nor laser functions to produce much force upon the web during operation. Accordingly, while the web preferably needs to be maintained in a relatively taut span to accommodate the aim and focus of the water jet and laser, the use of guide rolls, such as are used upstream and/or downstream of a disk-type slitter, are not required, although they may be used. In fact, it is anticipated that the cross-machine extending trough used to collect the water from the water jet can also be used to both effect the tension to provide a taut span in the traveling paper web as well as to maintain the severed edges of the web in the desired spaced adjacency, which may be only millimeters, or fractions thereof, in width. Further, it is contemplated that the interface between the traveling web and the trough could be air-lubricated to facilitate the operation.
In this invention, the laser is intended to be of much less power than would be required if the laser alone was utilized to slit the web. Further, since the laser is not utilized to sever the web, its beam does not have to be concentrated in the center of the web severance, but, perferably, is instead directed to the edges of the severance by use of a diffusion mode, such as, for example, the 01 mode which produces a beam in the shape of a donut, or torus, where the laser energy is not concentrated in a center spot, but is concentrated in a ring about a center spot. Other appropriate laser beam diffusion patterns can be utilized to either direct the laser's energy to the peripheral edges of a pattern, or in a pattern extending along the severance in the direction of web travel. Thus, such a pattern might resemble a rectangle extending along the severance, or it might take the form of two laterally arrayed spots relative to the direction of web travel (the so-called 11 mode). In any case, the laser's energy is concentrated to cut the protruding fibers and thus efficiently utilize its energy.
Accordingly, it is an object of this invention to provide an apparatus and method for efficiently slitting a paper web to produce strips having smooth, continuous edges on either side of the slit.
Another object of this invention is to provide an apparatus and method for slitting a traveling paper web utilizing a high pressure water jet in conjunction with a laser.
Still another object of this invention, as well as a feature and advantage thereof, is the provision of an apparatus and method for slitting a traveling web which does not utilize any cutting apparatus on one side of the web.
Another object, feature and advantage of this invention is to provide apparatus for producing a smooth cut in a traveling paper web wherein a water jet is utilized to sever the web and a relatively low power laser is utilized to provide a finished edge on the paper web on either side of the cut.
A feature and advantage of this invention is the use of a high pressure water jet in conjunction with a relatively low power laser to effect the slitting operation.
Another feature and advantage of this invention is the provision of a paper web slitting apparatus which permits the distance between the slit point and the point where the traveling web contacts the winder drum to be short.
Other objects, features and advantages of the invention will become readily apparent to those skilled in the art upon reading the following description of the preferred embodiments in conjunction with the attached drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side-elevational view, somewhat schematic in form, showing a water jet slitting nozzle and laser focused on a traveling paper web held taut over a water trough between a guide roll and a winder drum.
FIG. 2 is a close-up side-elevational view of the water jet and laser shown in FIG. 1.
FIG. 3 is another side-elevational view, similar to the views in FIGS. 1 and 2, but showing the water jet nozzle and laser focused at machine-direction aligned, but spaced, points on the traveling web.
FIG. 4 is a plan view of a traveling paper web showing, in exaggerated form, the web severance and cut by the water jet and laser, respectively, of the apparatus shown in FIGS. 1 and 2.
FIG. 5 is a plan view of a traveling web showing, in exaggerated form, the web severance and cut by the water jet and laser, respectively, of the apparatus shown in FIG. 3.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
As shown in FIG. 1, a roll of paper 10 which is rotatively supported on an unwind stand 12, is being unwound in the direction of arrow 14. The paper web W passes over the lower surface of a rotatable guide roll 16 over the upper surface of a trough, generally designated with numeral 18, and onto the lower surface of the front drum of a two-drum winder 19 which is winding the web into a new wound roll 20. The unwind stand, guide roll and two-drum winder are all well-known in the papermaking art and will not be discussed in detail further.
Referring to FIG. 2, trough 18 comprises an enclosed vessel 22 having an opening 24 in a curved top wall 26. In the preferred embodiment, vessel 22 comprises an elongate member extending substantially for the transverse width of the web W, and the opening 24 comprises a longitudinally extending slot, defined by a pair of spaced, parallel lips 25,25', and which extends along the length of the curved top for at least the width of the paper web W passing thereover.
The curved top is curved in an arc extending in the direction 28 of web travel so as to guide the traveling web in a curved path over its top surface and additionally produce a desired amount of web tension, or tautness, over the opening or slot as the trough is pressed into the web in the direction of arrow 30. This tautness can, of course, be produced by either moving the trough 18 in the direction 30 or, conversely, by moving the guide roll 16 downwardly opposite to direction 30 with reference to the orientation shown in FIG. 1.
A high pressure water jet nozzle 32 is shown disposed upstream of a laser 34. However, the relative orientation of the water jet nozzle and laser is not deemed to be of critical importance so long as the water jet nozzle and the laser are focused at the same general spot on the traveling web located over the slot, or opening, 24 in the top wall of the trough 18. However, it is important that the high pressure water jet nozzle be positioned relative to the laser so as to produce the web severing operation before the laser can trim the edges of the slit, as will be described in more detail subsequently.
At this point in the description, it might facilitate the understanding of the invention if the following terms to be used to describe the invention were explained in the context of their use and meaning relative to one another.
Accordingly, the term "sever" refers to the separation of the web into parts, portions or strips wherein the edges of the separated parts have no special condition and from which the ends of fibers protrude.
The term "cut" refers to a severance in the fibrous web where the edges of the parts have the ends of their protruding fibers cut off or removed, such as by being cut with a knife or burned away by a laser. Thus, a cut has a connotation of having smoother, more continuous, or defined edges than a severance.
The term "slit, or slitting" is used here as being generic to both sever and cut. It is used to describe, or refer to, the web severing procedure in the processing of paper during its manufacture wherein the web is separated longitudinally in the direction of web travel into one or more strips without particular concern regarding the condition of the edges of the strips produced.
The term "smooth" in reference to a strip edge refers to an essentially continuous, well defined line characterized by an absence, or near absence, of fiber ends or feathered portions protruding from the edge.
The term "spot" connotes a place having a small area, such as a small circle, as opposed to a point which essentially has no area. In this context, therefore, a laser focused over a spot which is moved longitudinally along the length of a traveling paper web creates a cut having a small, but definite, width in the web. In other words, the web traveling beneath the laser spot produces strips having laterally spaced edges.
Finally, in this discussion, corresponding elements in different embodiments will be correspondingly numbered with different letter postscripts to distinguish between them. Similarly, corresponding elements in the same embodiment will be numbered the same with different prime superscripts used to distinguish between them.
In FIG. 3, the high pressure water jet nozzle 32a is aligned in tandem with the laser 34a and is disposed upstream of the laser in the direction 28 of web travel. In the trough 18a, corresponding openings 24a,24a' are located in the top wall 26a beneath the water jet nozzle 32a and laser 34a, respectively. As in the embodiment shown in FIG. 2, openings 24a,24a' can take the form of either a hole beneath the jet nozzle or laser, or comprise a slot extending longitudinally in the trough. In either case, the tension of the web over the lips defining the openings produces a taut span in the web. In this arrangement, the web severing function provided by the high pressure water jet 36a and the cutting function provided by the laser beam 38a are separated to a greater extent to provide more control over the operation of both functions. A wall 40 extends longitudinally along the trough between the openings 4a,24a' in the upper wall.
In both of the configurations shown in FIGS. 2 and 3, the laser is equipped with a concentrically disposed chamber 42,42a which has an annular nozzle 44,44a concentric with the laser beam 38,38a so as to surround the laser beam with a stream of pressurized air supplied by an air pump 46,46a which introduces the pressurized air into the chamber 42,42a through a tube 48,48a and out through opening 45,45a.
In operation, with reference to FIGS. 1, 2 and 4, a traveling web W is unwound from a roll of paper 10 and is guided over the surfaces of rotating guide roll 16 and the first drum 17 of two-drum winder 19. A curved surface 26 of a trough 18 is brought into sliding engagement with the lower surface of the web W as it travels in the direction 28 to produce tension in the web. An elongate slot 24 in the curved top wall 26 of the trough thus creates a taut span between the leading and trailing lips 25,25' in the slot 26. The web, thus supported by the lips, offers considerable resistance to the impingement force of the water jet 36 emitted under high pressure from water nozzle 32 against a spot 50 (FIG. 4) on the top surface of web W.
Also aimed at a spot 52 (FIG. 4) on the web, which spot 52 is either no further upstream than spot 50, and preferably is slightly downstream of spot 50, is laser beam 38. The force of the impinging jet of water 36 severs the web and creates a severance S having a width equal to the diameter of the water jet 36.
The web severance produced by the impinging water jet does not cut individual fibers in the paper web W but, rather, abrades the wood pulp fibers comprising the paper web and washes away fines, fillers and, perhaps, individual short paper fibers to produce the severance. However, this abrading action by the water jet leaves the ends F of individual fibers extending from the edges E of the severance extending into the severance from either side thereof.
The laser beam 38, which does not have to be powerful enough to pierce the paper web by itself, can, therefore, have its beam aligned with the slit S such that the cross-machine distance or diameter of the spot of the laser beam 52 extends for a diameter at least equal to the slit width S and, optionally, for a cut distance C which is slightly greater than the distance S. In either case, the laser burns away at least the ends F of the individual fibers extending into the slit such that the cut C produced has edges E,E', which are smooth and continuous. It is within the concept of the invention that a small portion of the edges themselves can be burned away in the process to produce the smooth, continuous edges.
To facilitate the water jet/laser slitting process, a source of pressurized air, such as supplied by air pump 46, via tube 48 to an air nozzle 44 blows compressed air against the slit through an annular opening 45 about the laser beam 38.
Beneath the web W is the vessel 22 which catches and collects the water from the water jet. This water also intercepts any particles, such as fines, fillers and protruding ends of fibers liberated by the laser beam. The water pool in the vessel 22 also serves to intercept and diffuse the laser beam and to screen the laser beam from the eyes of operating personnel who might be near the apparatus.
In the embodiment shown in FIGS. 3 and 5, the water jet and laser have been spaced further apart along the direction 28 of web travel so as to essentially be in tandem. Except for the fact that the water jet and laser beam are aimed at different spots 50a,52a (FIG. 5) on the web, the operation of the apparatus to produce the slit is the same as described in conjunction with FIGS. 1, 2 and 4. In this embodiment, the laser spot 52a is of the same diameter as the water jet spot 50a so the protruding fiber ends F are the only material encountered by the laser beam so the cut C and the smooth, continuous edges E,E' produced by burning off the protruding ends F of the fibers can be effected with a laser having even less power than the laser used in conjunction with FIGS. 1, 2 and 4. Since the water jet and laser beam are directed to different areas on the web, this arrangement also permits somewhat greater flexibility in fine-tuning the apparatus to both sever the web S and create the cut C.
Finally, the trough 18,18a in either embodiment can be bowed in its longitudinal direction, that is, about an axis extending in the direction of web travel, so as to produce a slight spreading force on the slit web to maintain the slit portions Ws,Ws' biased outwardly away from one another in the direction of arrows 54,54'.
Thus, an apparatus and method have been shown and described which achieves the objects and exhibits the features and advantages set forth. It is anticipated that variations in the invention can be made without departing from the spirit and scope of the appended claims. Accordingly, such variations are intended to be within the scope of the claims. | A high pressure water jet is used in conjunction with a relatively low power laser to produce a smooth cut in a traveling web. The cutting procedures produces a relatively small amount of fiber dust in the atmosphere surrounding the cutting operation. The water jet severs the traveling web into separate parts, and the laser is directed to the severed edges to burn away the protruding ends of the paper fibers to produce a uniform, smooth cut in both severed edges. A trough is disposed on the side of the web opposite the water jet and laser to receive and collect the water severing the web and the fiber dust, and to diffuse the laser beam emissions. | 1 |
The present Application is a division of U.S. patent application Ser. No. 12/622,461 filed on Nov. 20, 2009, now U.S. Pat. No. 8,129,095 issued Mar. 6, 2012, which further claims domestic priority to provisional U.S. application 61/167,591 filed on Apr. 8, 2009.
FIELD OF THE INVENTION
The present invention relates to methods for forming damascene metal wires for integrated circuit chips and more specifically, it relates methods for increasing wire uniformity while avoiding parasitic proximity effects that reduce integrated circuit chip performance.
BACKGROUND OF THE INVENTION
The chemical mechanical polishing process used in the manufacture of damascene wires in order requires uniform pattern density to avoid degradation in damascene wire performance due to wire non-uniformity. However, the very techniques such as adding fill shapes to wiring layers, while improving pattern density can themselves adversely affect the damascene wire performance. Accordingly, there exists a need in the art to eliminate or mitigate the deficiencies and limitations described hereinabove.
SUMMARY OF THE INVENTION
A first aspect of the present invention is a method, comprising: simultaneously forming a multiplicity of damascene wires and a multiplicity metal dummy shapes in a dielectric layer of a wiring level of an integrated circuit chip, the metal dummy shapes dispersed between damascene wires of the multiplicity of damascene wires; and removing or modifying those metal dummy shapes of the multiplicity of metal dummy shapes within exclusion regions around selected damascene wires of the multiplicity of damascene wires.
A second aspect of the present invention is a method, including: (a) generating a design of a wiring level of an integrated circuit chip, the design including data describing wires of the wiring level and data describing exclusion regions around wires of the wiring level; after (a), (b) generating a wiring level shapes file including wire shapes from the data describing the wires of the wiring level; (c) generating a metal dummy shape removal/modification shapes file including metal dummy shape removal/modification shapes from the data describing the wires of the wiring level and the data describing the exclusion regions; after (b), (d) adding metal fill shapes to the wiring level shapes between one or more of the wire shapes; and after (b) and (d), (e) generating a first photomask data set from the wiring level shapes file and a second photomask data set from the metal dummy shape removal/modification shapes file.
A third aspect of the present invention is a reticle for use in a fabricating a wiring level of an integrated circuit chip, comprising: a first cell including mask shapes defining damascene wires and metal dummy shapes for a first photolithographic fabrication step of the wiring level; and a second cell including mask shapes defining a subset of the metal dummy shapes to be removed or modified for a second photolithographic fabrication step of the wiring level.
BRIEF DESCRIPTION OF THE DRAWINGS
The features of the invention are set forth in the appended claims. The invention itself, however, will be best understood by reference to the following detailed description of an illustrative embodiment when read in conjunction with the accompanying drawings, wherein:
FIG. 1 is top view of a region of wire level of an integrated circuit chip design according to embodiments of the present invention;
FIG. 2 is top view of the region of a wire level of an actual integrated circuit chip corresponding to the region of FIG. 1 after initial processing steps according to embodiments of the present invention;
FIG. 3 is a cross-section through line 3 - 3 of FIG. 2 ;
FIG. 4 is top view of a region of a wire level of an actual integrated circuit chip corresponding to the region of FIG. 1 after a metal dummy shape removal photolithography step according to embodiments of the present invention;
FIG. 4A illustrates an alternative photoresist pattern to that of FIG. 4 ;
FIG. 5 is a cross-section through line 5 - 5 of FIG. 4 ;
FIGS. 6 , 7 and 8 are is cross-sections through line 5 - 5 of FIG. 4 illustrating additional process steps according to embodiments of the present invention;
FIGS. 9A , 9 B and 9 C are detailed views of the steps illustrated in FIGS. 6 , 7 and 8 according to a first alternative processing scheme of the present invention;
FIGS. 10A , 10 B and 10 C are detailed views of the steps illustrated in FIGS. 6 , 7 and 8 according to a second alternative processing scheme of the present invention;
FIG. 11 is a top view of the same region as illustrated in FIG. 2 after processing according to the first alternative processing scheme;
FIG. 12 is a top view of the same region as illustrated in FIG. 2 after processing according to the second alternative processing scheme;
FIG. 13 is a flowchart of the method of the embodiments of the present invention;
FIG. 14 is a plan view of a multi-layer multi-chip reticle that may be used in practicing the embodiments of present invention; and
FIG. 15 is a schematic block diagram of a general-purpose computer that may be used in the design of photomasks according to embodiments of the present invention
DETAILED DESCRIPTION OF THE INVENTION
A damascene process is one in which wire trenches or via openings are formed in a dielectric layer, an electrical conductor of sufficient thickness to fill the trenches is deposited in the trenches and on a top surface of the dielectric, and a chemical-mechanical-polish (CMP) process is performed to remove excess conductor and make the surface of the conductor co-planar with the surface of the dielectric layer to form damascene wires (or damascene vias). When only a trench and a wire (or a via opening and a via) is formed the process is called single-damascene.
A via first dual-damascene process is one in which via openings are formed through the entire thickness of a dielectric layer followed by formation of trenches part of the way through the dielectric layer in any given cross-sectional view. A trench first dual-damascene process is one in which trenches are formed part way through the thickness of a dielectric layer followed by formation of vias inside the trenches the rest of the way through the dielectric layer in any given cross-sectional view. All via openings are intersected by integral wire trenches above and by a wire trench below, but not all trenches need intersect a via opening. An electrical conductor of sufficient thickness to fill the trenches and via opening is deposited on a top surface of the dielectric and a CMP process is performed to make the surface of the conductor in the trench co-planar with the surface the dielectric layer to form dual-damascene wires and dual-damascene wires having integral dual-damascene vias.
Fill shapes exist in shapes files of wiring levels of a circuit design and become photomask shapes on photomasks generated from the circuit design. Fill shapes result in dummy shapes on actual integrated circuit chips. Dummy shapes may exist as dielectric islands (i.e., dielectric dummy shapes) embedded in single-damascene or dual-damascene wires or as single-damascene or dual-damascene metal islands (i.e., metal dummy shapes) between single-damascene or dual-damascene wires and vias in a wiring level of an integrated circuit chip. Metal dummy shapes are defined as shapes not electrically connected to any wire or via contained in the same wiring level as the metal dummy shapes or to any other metal wire or via in other wiring levels.
The embodiments of the present invention will be described and illustrated in a single wiring level using single-damascene technology. It should be understood that the invention may be practiced on multiple wiring levels of an integrated circuit chip and may be practiced using dual-damascene technology or a combination of single-damascene and dual-damascene technology. Hereinafter, the term damascene (without the qualifiers “single” or “dual” should be understood to mean single-damascene or dual-damascene.
FIG. 1 is top view of a region of wire level of an integrated circuit chip design according to embodiments of the present invention. In FIG. 1 , a portion of an interconnect level design 100 of an integrated circuit chip includes wire shapes 105 , 110 , 115 , 120 and 125 . Wire shapes 115 and 120 correspond, after fabrication, to damascene wires whose performance may be adversely affected by the presence of metal dummy shapes within an exclusion region 130 (i.e., the region within heavy lines).
FIG. 2 is top view of the region of a wire level of an actual integrated circuit chip corresponding to the region of FIG. 1 after initial processing steps according to embodiments of the present invention. In FIG. 2 , region 100 A corresponds to region 100 of FIG. 1 . Damascene wires 105 A, 110 A, 115 A, 120 A and 125 A correspond respectfully to wire shapes 105 , 110 , 115 , 120 and 125 of FIG. 1 . Wires 105 A, 110 A, 115 A, 120 A and 125 A are formed in a dielectric layer 135 . Also formed in dielectric layer 135 are metal dummy shapes 140 . Wires 105 A, 110 A and 125 A include dielectric dummy shapes 145 . Dummy shapes 140 and 145 have the effect of providing uniform local (e.g., within region 100 A) and global (e.g., the integrated circuit chip or a core) metal pattern density for the CMP process. Without uniform metal pattern density, because of hardness differences between metal and dielectric materials, some wires may dish (the surface becomes concave), so the wire is thinner than designed slowing down signal transmission. Columns 150 A, 150 B, 150 C, and 150 D of dummy shapes 140 are of particular interest because they are within exclusion region 130 (small dash line). In one example, wires 105 A, 110 A, 115 A, 120 A and 125 A and dummy shapes 140 includes an optional electrically conductive liner and a core conductor. In one example, the liner may comprise layers of titanium and/or titanium nitride or layers of tantalum and/or tantalum nitride. Titanium, titanium nitride, tantalum and tantalum nitride may be deposited by sputtering. In one example, the core conductor may comprise copper or tungsten. Copper may be deposited electrochemically (i.e., by plating). Tungsten may be deposited by chemical vapor deposition or sputtering.
FIG. 3 is a cross-section through line 3 - 3 of FIG. 2 . In FIG. 3 , dielectric layer 135 is formed on a semiconductor substrate 155 . Substrate 155 may include devices such as transistors and other wiring levels similar to the wiring level containing dielectric layer 135 , wires 105 A, 110 A, 115 A, 120 A and 125 A and dummy shapes 140 .
FIG. 4 is top view of a region of a wire level of an actual integrated circuit chip corresponding to the region of FIG. 1 after a metal dummy shape removal photolithography step according to embodiments of the present invention. In FIG. 4 , the photolithography step, but not the actual dummy shape removal has been performed.
A photolithographic process is one in which a photoresist layer is applied to a surface, the photoresist layer exposed to actinic radiation through a patterned photomask and the exposed photoresist layer developed to form a patterned photoresist layer. When the photoresist layer comprises positive photoresist, the developer dissolves the regions of the photoresist exposed to the actinic radiation and does not dissolve the regions where the patterned photomask blocked (or greatly attenuated the intensity of the radiation) from impinging on the photoresist layer. When the photoresist layer comprises negative photoresist, the developer does not dissolve the regions of the photoresist exposed to the actinic radiation and does dissolve the regions where the patterned photomask blocked (or greatly attenuated the intensity of the radiation) from impinging on the photoresist layer. After further processing (e.g., an etch or an ion implantation), the patterned photoresist is removed. The photoresist layer may optionally be baked at one or more of the following steps: prior to exposure to actinic radiation, between exposure to actinic radiation and development, after development.
Returning to FIG. 4 , photoresist islands 160 (heavy lines) are formed on wires 105 A, 110 A, 115 A, 120 A, and 125 A and all dummy shapes 140 but not on dummy shapes in columns 150 A, 150 B, 150 C and 150 D which are within exclusion region 130 .
FIG. 4A illustrates an alternative photoresist pattern to that of FIG. 4 . In FIG. 4A , a patterned photoresist layer 160 A includes openings 162 over dummy shapes 140 A that are to be removed or modified, but not over dummy shapes 140 B that are to be left in place.
FIG. 5 is a cross-section through line 5 - 5 of FIG. 4 . In FIG. 5 , photoresist islands 160 protect wires 105 A, 110 A, 115 A, 120 A, and 125 A and all dummy shapes 140 except which are within region 130 .
FIGS. 6 , 7 and 8 are cross-sections through line 5 - 5 of FIG. 4 illustrating additional process steps according to embodiments of the present invention. In FIG. 6 an etch step is performed to remove all or a portion of dummy shapes 140 (see FIG. 5 ) in columns 150 A, 150 B (see FIG. 4 ), 150 C and 150 D (see FIG. 4 ) to form dummy trenches 165 X (where X is either A or B, see infra) in dielectric layer 135 and then photoresist islands 160 (see FIG. 5 ) are removed. The etch step may be either a wet etch or a dry etch (e.g., a reactive ion etch (RIE) or a plasma etch) or combinations of wet and dry etches. When dummy shapes 140 (see FIG. 5 ) are copper (or have a copper core conductor), a wet etch may be performed using a dilute mixture of HCl and hydrogen peroxide or a RIE using HCl and/or HBr plasma process feed gases may be used. Optionally hydrogen gas may be added to the RIE plasma process feed gas. In one example, dissociation of HCl and/or HBR are the sole source of the reactive copper etching species generated by the plasma. In one example, dissociation of HCl and/or HBR provides at least about 40% of the reactive copper etching species generated by the RIE plasma. In one example, dissociation of HCl and/or HBR provides at least about 50% of the reactive copper etching species generated by the RIE plasma. In one example, dissociation of HCl and/or HBR provides at least about 80% of the reactive copper etching species generated by the RIE plasma.
In FIG. 7 , a dielectric layer 170 is deposited completely filling in trenches 165 X.
In FIG. 8 , a CMP is performed creating plugs 175 X (where X is either A or B, see infra) and exposing top surfaces of wires 105 A, 110 A, 115 A, 120 A and 125 A, dummy shapes 140 (and 145 see FIG. 2 ) and a top surface of dielectric layer 135 . In one example, dielectric layer is a same material as dielectric layer 135 . In one example, dielectric layers 135 and 170 comprise silicon dioxide. In one example, dielectric layer 135 and 170 are independently selected from the group consisting of hydrogen silsesquioxane polymer (HSQ), methyl silsesquioxane polymer (MSQ), polyphenylene oligomer, methyl doped silica or SiO x (CH 3 ) y or SiC x O y H y or SiOCH), organosilicate glass (SiCOH), and porous SiCOH, silicon dioxide (SiO 2 ), silicon nitride (Si 3 N 4 ), silicon carbide (SiC), silicon oxy nitride (SiON), silicon oxy carbide (SiOC), organosilicate glass (SiCOH), plasma-enhanced silicon nitride (PSiN x ) or NBLok (SiC(N,H)).
FIGS. 9A. 9B and 9 C are detailed views of the steps illustrated in FIGS. 6 , 7 and 8 according to a first alternative processing scheme of the present invention. In FIG. 9A , dummy shape 140 includes an optional electrically conductive liner 180 and a core conductor 185 . Materials for liner 180 and core conductor 185 are the same as for wires 105 A, 110 A, 115 A, 120 A and 120 C (see FIG. 2 ) described supra. In FIG. 9B , both liner 180 and core conductor 185 are removed to form trench 165 A. In FIG. 9C , trench 165 A (see FIG. 9B ) is filled with dielectric 170 to form plug 175 A. If, in FIG. 9A , if dummy shape 140 includes no liner 180 , only core conductor 185 , then the structure illustrated in FIG. 9C still results.
FIGS. 10A. 10B and 10 C are detailed views of the steps illustrated in FIGS. 6 , 7 and 8 according to a second alternative processing scheme of the present invention. In FIG. 10A , dummy shape 140 includes electrically conductive liner 180 and core conductor 185 . In FIG. 10B , only core conductor 185 is removed to form a liner 180 lined trench 165 B. In FIG. 10C , trench 165 B (see FIG. 10B ) is filled with dielectric 170 to form plug 175 B where dielectric 170 is separated from dielectric layer 135 by liner 180 .
FIG. 11 is a top view of the same region as illustrated in FIG. 2 after processing according to the first alternative processing scheme. FIG. 11 is similar to FIG. 2 except dummy shapes 140 (see FIG. 2 ) of columns 150 A, 150 B, 150 C, and 150 D are replaced with plugs 175 A, which consist of dielectric material. Thus there are no metal dummy shapes or portions of metal dummy within exclusion region 130 . Because plugs 175 A consist of dielectric material, plugs 175 A will not interact with signals on wires 115 A and 115 B as dummy shapes 140 would have.
FIG. 12 is a top view of the same region as illustrated in FIG. 2 after processing according to the second alternative processing scheme. FIG. 12 is similar to FIG. 2 except dummy shapes 140 (see FIG. 2 ) of columns 150 A, 150 B, 150 C, and 150 D are replaced with plugs 175 B, which consist of dielectric material and the liner of metal shapes. Thus all metal dummy shapes within exclusion region 130 consist of cores of dielectric material surrounded by an electrically conductive liner. Because liners are relatively thin, plugs 175 B will interact with signals on wires 115 A and 115 B to a lesser extent than dummy shapes 140 would have.
FIG. 13 is a flowchart of the method of the embodiments of the present invention. Generally the design of an integrated circuit chip is in the form of a hardware description language (HDL) data file or a netlist (a data file that describes how individual design components are connected together) and essentially describes the wires of the wiring levels. Generally, in conventional design practice for integrated circuit chips, netlists are generated from HDL files and shapes files are generated from netlists.
In step 200 , wiring levels of an integrated circuit chip are designed. The HDL data file or the netlist file include exclusion region data describing exclusion regions where metal dummy shapes are to be removed or modified in physical wiring levels of the integrated circuit chip and wire data describing the actual wires in the integrated circuit chip.
In step 205 , wire shapes files and metal dummy shape removal/modification shapes files are generated. When the HDL/netlist files are used to generate wire shapes the wire data is used and the exclusion region data are ignored. When the HDL/netlist files are used to generate metal dummy shape removal/modification shapes both the exclusion region data and wire data are used. The metal dummy shape removal/modification shape files are tagged to corresponding wire shapes file.
In step. 210 , fill shapes are added to the wiring level shape files. The fill shapes may include metal fill shapes placed between wire shapes and dielectric fill shapes placed within wire shapes. In an exemplary methodology, a fill shape tool places metal fill shapes into the wire level shapes file. The fill shape tool is forbidden to place metal fill shapes that overlap the boundaries of the exclusion regions. Thus the fill shapes are placed completely within and completely without the exclusion region as other fill shape tool rules determine and metal fill shapes so placed do not overlap the boundaries of the exclusion region.
In step 215 , wire level photomask data sets and dummy shape removal/modification photomask data sets are generated using, respectively, the wire shapes files and the dummy shape removal/modification shapes files. These photomask data sets are used to generate actual photomasks for each wiring level. For each wiring level, the photomasks may include a first mask having wire shapes and metal and/or dielectric fill shapes and second mask having metal dummy shape removal/modification shapes or a single mask having a first cell having wire shapes and metal and/or dielectric fill shapes and second cell having metal dummy shape removal/modification shapes.
In step 220 , a wiring level of the integrated circuit chip is fabricated including all wires and metal dummy shapes using a photomask or photomask cell having wire shapes and metal dummy shapes.
In step 225 , if a metal dummy shape removal/modification mask or cell exists for the wiring level, some of the metal dummy shapes are removed or modified using the metal dummy shape removal/modification mask or the metal dummy shape removal/modification cell.
In step 230 , if other wiring levels remain to be fabricated, steps 220 and 225 are repeated; otherwise in step 235 , the integrated circuit chip is completed.
FIG. 14 is a plan view of a multi-layer multi-chip reticle that may be used in practicing the embodiments of present invention. In FIG. 14 , a reticle 250 includes four cells 255 , 260 , 265 and 270 . Cells 255 and 260 are used to define wires and dummy shapes of two integrated circuit chips at the same time in a first photolithographic process. Cells 265 and 270 are used to define where dummy shapes will be removed or modified of two integrated circuit chips at the same time in a second and separate photolithographic process. This saves the resources required to fabricate two separate photomasks.
Generally, the method described herein with respect to designing photomasks for removal or modification of dummy shapes is practiced with a general-purpose computer and the methods described supra in steps 200 through 215 of the flow diagrams of FIG. 13 may be coded as a set of instructions on removable or hard media for use by the general-purpose computer.
FIG. 15 is a schematic block diagram of a general-purpose computer that may be used in the design of photomasks according to embodiments of the present invention. In FIG. 15 , computer system 300 has at least one microprocessor or central processing unit (CPU) 305 . CPU 305 is interconnected via a system bus 310 to a random access memory (RAM) 315 , a read-only memory (ROM) 320 , an input/output (I/O) adapter 325 for a connecting a removable data and/or program storage device 330 and a mass data and/or program storage device 335 , a user interface adapter 340 for connecting a keyboard 345 and a mouse 350 , a port adapter 355 for connecting a data port 360 and a display adapter 365 for connecting a display device 370 .
ROM 320 contains the basic operating system for computer system 300 . The operating system may alternatively reside in RAM 315 or elsewhere as is known in the art. Examples of removable data and/or program storage device 630 include magnetic media such as floppy drives and tape drives and optical media such as CD ROM drives. Examples of mass data and/or program storage device 335 include electronic, magnetic, optical, electromagnetic, infrared, and semiconductor devices. Examples of a computer-readable medium include a semiconductor or solid-state memory, magnetic tape, a removable computer diskette, a random access memory (RAM), a read-only memory (ROM), a rigid magnetic disk and an optical disk. Current examples of optical disks include compact disk-read only memory (CD-ROM), compact disk-read/write (CD-R/W) and DVD. In addition to keyboard 345 and mouse 350 , other user input devices such as trackballs, writing tablets, pressure pads, microphones, light pens and position-sensing screen displays may be connected to user interface 340 . Examples of display devices include cathode-ray tubes (CRT) and liquid crystal displays (LCD).
A computer program with an appropriate application interface may be created by one of skill in the art and stored on the system or a data and/or program storage device to simplify the practicing of this invention. In operation, information for or the computer program created to run the present invention is loaded on the appropriate removable data and/or program storage device 330 , fed through data port 360 or typed in using keyboard 345 .
Thus the embodiments of the present invention provide methods for using fill shapes to improve damascene wire performance without parasitic degradation or with reduced parasitic degradation of the performance of damascene wires by those same fill shapes. Further embodiments of the present invention provide photomasks and methods of designing photomasks that allow removal or modification of dummy shapes.
The description of the embodiments of the present invention is given above for the understanding of the present invention. It will be understood that the invention is not limited to the particular embodiments described herein, but is capable of various modifications, rearrangements and substitutions as will now become apparent to those skilled in the art without departing from the scope of the invention. Therefore, it is intended that the following claims cover all such modifications and changes as fall within the true spirit and scope of the invention. | A method of improving damascene wire uniformity without reducing performance. The method includes simultaneously forming a multiplicity of damascene wires and a multiplicity of metal dummy shapes in a dielectric layer of a wiring level of an integrated circuit chip, the metal dummy shapes being dispersed between damascene wires of the multiplicity of damascene wires; and removing or modifying those metal dummy shapes of the multiplicity of metal dummy shapes within exclusion regions around selected damascene wires of the multiplicity of damascene wires. Also a method of fabricating a photomask and a photomask for use in improving damascene wire uniformity without reducing performance. | 7 |
This application is a continuation of PCT/IB01/02598 filed Dec. 20, 2001, for which a national stage application was filed on Mar. 2, 2004 as U.S. patent application Ser. No. 10/250,491, now U.S. Pat. No. 7,406,049 with an issue date of Jul. 29, 2008.
FIELD OF THE INVENTION
The present invention relates generally to management of protocol information in PNNI (Private Network-to-Network Interface) networks.
BACKGROUND OF THE INVENTION
Before discussing the invention in more detail, it is useful to consider some background. PNNI is a hierarchical, dynamic link-state routing protocol defined by the ATM Forum for use in ATM networks. The PNNI protocol provides, inter alia, a system for creation and distribution of topology information which determines how individual network nodes “see” the network and thus how nodes communicate. A key feature of the protocol is the ability to cluster groups of switches into “peer groups”. The details of each peer group are abstracted into a single “logical group node” (LGN) which is all that can be seen outside of that peer group. One node in each peer group serves as the “peer group leader” (PGL) and represents that peer group as the LGN in the next level up of the hierarchy. This system is applied recursively so that PNNI can hierarchically aggregate network topology information. Reachable addresses, if they are internal to a peer group, may be summarized by a single ATM summary address which is generated by the LGN. The PNNI topology information available to switches is such that each switch sees the details of its own peer group plus the details of any peer group that represents it at a higher level of the PNNI hierarchy. It is this hierarchical topology abstraction that reduces the resources required to support large-scale ATM networks. Another advantage of PNNI is that it is scalable and can therefore be used in large heterogeneous networks.
In PNNI, the topology data and routing information is contained in so-called information groups (IGs). The information groups include data relating to nodes, links and addresses which can be accessed by network devices. The information groups are communicated over PNNI networks in PNNI Topology State Elements (PTSEs). PTSEs are created and distributed by nodes so that each node can maintain a topology database which defines its view of the PNNI network. PTSEs are flooded among neighboring nodes so that each node in a peer group has the same topology database and thus the same view of the network. In the next level up of the hierarchy, however, the peer group topology is abstracted into a single logical node as described above. The LGN generates PTSEs advertising addresses accessible within its child peer group and distributes these to its neighbors in the next level of the hierarchy, but the details of nodes and links within the peer group are lost. PTSEs generated by a LGN in this way are also flooded back down the hierarchy, together with PTSEs received by the LGN from its neighbors, to enable the lower-level nodes to identify their “ancestors” (i.e. their representative nodes at higher levels) and maintain their views of the PNNI topology.
PNNI provides full support for mobility at the ATM layer (“PNNI Addendum for Mobility Extensions v1.0”, ATM Forum af-ra-0123.000, April 1999). For example, the PNNI mobility extensions allow a LGN abstracting a mobile ATM network to roam in the PNNI hierarchy of a terrestrial backbone network. Routing information detailing the current location of the mobile network is advertised through regular PNNI, thus enabling the establishment of calls from a terrestrial end-system to an end-system of the mobile network, and vice versa. In addition, ATM networks can be used to carry higher layer protocol information such as IP (Internet Protocol) information. This can conveniently be done by employing an extension to the PNNI protocol known as PAR (PNNI Augmented Routing). PAR is described, for example in “PNNI Augmented Routing (PAR)”, af-ra-0104.000, ATM Forum, January 1999. Briefly, PAR allows IP information, which is not related to operation of the ATM network in itself, to be distributed over the network. PAR makes use of the PTSEs discussed above to distribute IP-related information in addition to the ATM topology information. PAR-enabled devices in the network encapsulate IP information in PTSEs which are then distributed in the usual PNNI way. The IP information in these so-called “PAR PTSEs” is opaque to PNNI nodes that are not PAR-enabled, but other PAR-enabled nodes are aware of the format of the IP information in PAR PTSEs. Thus, a PAR-enabled device in the network can communicate IP information over the network by means of PAR PTSEs, and another PAR-enabled device can extract the IP information.
A further extension of the PNNI protocol known as “Proxy-PAR” allows higher layer protocol devices, in particular IP devices such as routers, to communicate IP information over the network without themselves participating in PNNI. Proxy-PAR is also described in “PNNI Augmented Routing (PAR)”, af-ra-0104.000, ATM Forum, January 1999. Briefly, Proxy-PAR is a simple exchange protocol which allows the integration of IP devices into ATM networks without the need for the IP devices to run PNNI at all. An IP device can be connected to the network via a PAR-enabled device which is configured as a Proxy-PAR server. The IP device itself is configured as a Proxy-PAR client. In accordance with Proxy-PAR, the Proxy-PAR client can register details of the IP services it supports with the Proxy-PAR server. This information is then encapsulated in PAR PTSEs as previously described and flooded in the network in the usual PNNI way. The Proxy-PAR client can also request the Proxy-PAR server for information on other IP devices connected in the network for which PAR PTSEs have been received by the PAR-enabled device as previously described. In this way, IP information is communicated between IP devices without the devices participating in PNNI.
Through use of PAR and Proxy-PAR as described above, protocol devices, in particular IP devices, can learn about each other via this communication of protocol information over the PNNI network, avoiding the need for manual input in each device of the protocol information needed for configuration of the higher layer protocol topology. For example, IP routers at the edge of an ATM cloud can learn about each other, and manual configuration of the IP adjacencies can be avoided. Further, our copending European Patent Application No. 99115544.1, filed 6 Aug. 1999, discloses mechanisms for dynamic configuration of OSPF (Open Shortest Path First) interfaces in IP routers. Routers in mobile networks, for example, can dynamically configure OSPF interfaces with the OSPF area of other (fixed or mobile) network routers as the mobile network roams and makes new connections. Whether or not OSPF interfaces are configured dynamically, PAR and Proxy-PAR allow routers to register their protocol information (e.g. IP address, ATM address, OSPF area) with their serving ATM switches which then flood the data throughout the network. Other routers can retrieve this IP information by querying their serving ATM switches. Routers can then exchange routing information to form neighbor relationships, or “peer”, in the usual way with other routers they learn about from the information received. The resulting IP topology is shaped by this peering between routers.
In an ideal PNNI network, an entire child peer group can be represented by a single summary address and the LGN. However, in non-ideal PNNI networks, such as networks containing non-aggregated (e.g.: non-summarizable) ATM reachable addresses or networks that use, for example, Proxy-PAR, the PNNI hierarchy causes duplication of information at each level of the hierarchy. This stems from the generation, at the LGN, of non-aggregated information groups and information groups which duplicate information derived from the child peer groups. The contents of these information groups is duplicated and propagated one level higher by repackaging it in a new PTSE. These regenerated PTSEs are flooded horizontally to all of the immediate neighbors of the LGN and flooded downwards into the child peer group of the LGN. Such flooding produces two different PTSEs containing the same information groups. This process occurs at each layer of the hierarchy. It would be clearly desirable to reduce this inefficiency.
SUMMARY OF THE INVENTION
In accordance with the present invention, there is now provided a method for managing flow of protocol information in a node of a hierarchical network in which the protocol information is communicated between network nodes in topology state elements, the method comprising: checking topology state elements generated by the node to identify protocol information encapsulated therein; and, selectively allowing transmittal of the topology state elements from the node to lower levels of the network based on the protocol information identified.
This advantageously prevents the aforementioned duplication of information at multiple levels of a hierarchical network thereby saving database memory, link bandwidth, and protocol processing
The selective allowing of transmittal of the topology state elements to lower levels of the network preferably comprises comparing the protocol information identified with a lookup table to determine, based on the protocol information identified, if transmittal of the topology state elements to lower levels of the network is allowed.
In preferred embodiments of the present invention, the network comprises a PNNI network and the topology state elements are PTSEs. However, the present invention is not limited in application to PNNI networks. Other hierarchical network formats may equally benefit from the present invention.
In embodiments of the present invention applicable to PNNI networks, the protocol information for which transmittal to lower levels of the network is disallowed comprises Internal Reachable ATM Address, External Reachable ATM Address, Nodal State Parameter, Uplinks, and PAR Service protocol information, and the protocol information for which transmittal to lower levels of the network is allowed comprises Nodal and Horizontal Link protocol information.
The node may comprise a switch or similar network infrastructure device.
The present invention also extends to a switch for connection to a hierarchical network, the switch comprising control logic for performing a method for managing flow of protocol information as herein before described.
BRIEF DESCRIPTION OF THE DRAWINGS
Preferred embodiments of the invention will now be described, by way of example, with reference to the accompanying drawings in which:
FIG. 1 is a block diagram of a PNNI network hierarchy;
FIG. 2 is a table of PTSEs stored in switches of the PNNI network;
FIG. 3 is a block diagram of another PNNI network hierarchy;
FIG. 4 is a schematic block diagram of a switch and associated router embodying the invention; and,
FIG. 5 is a flow diagram of a method for managing flow of protocol information in a PNNI network in accordance with a preferred embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
A preferred embodiment of the present invention will be described shortly. Before describing operation of the embodiment, particular problems addressed by the embodiment will be explained with reference to FIGS. 1 and 2 .
Referring first to FIG. 1 , this shows a representative PNNI hierarchical network comprising three levels, 10 , 20 and 30 . Level 10 comprises 3 peer groups, 40 to 60 . Level 20 comprises two peer groups, 70 and 80 . Level 30 comprises a single peer group 90 . Peer group 60 comprises nodes 1 . 0 . 1 and 1 . 0 . 2 , with node 1 . 0 . 2 serving as being the PGL. Peer group 50 comprises nodes 1 . 1 . 1 and 1 . 1 . 2 , with node 1 . 1 . 2 serving as the PGL. Peer group 40 comprises nodes 2 . 0 . 1 and 2 . 0 . 2 , with node 2 . 0 . 1 serving as the PGL. Peer group 70 comprises PGL 2 . 0 representing peer group 40 . Peer group 80 comprises LGN 1 . 1 representing peer group 50 and LGN 1 . 0 representing peer group 60 . LGN 1 . 1 serves as the PGL in peer group 70 . Peer group 90 comprises LGN 2 representing peer group 70 and LGN 1 representing peer group 80 . In practice, Nodes 1 . 01 , 1 . 0 . 2 , 1 . 1 . 1 , 1 . 1 . 2 , 2 . 0 . 1 , 2 . 02 , may each be implemented by an ATM switch or similar devices. An example of such a switch will be described later with reference to Figure X. Nodes 1 . 0 . 2 and LGN 1 . 0 are implemented in the same switch. Likewise, nodes 1 . 1 . 2 , 1 . 1 and 1 are implemented in the same switch. Similarly, nodes 2 . 01 , 2 . 0 and 2 are implemented in the same switch.
As mentioned earlier, the PNNI protocol is based on a rule that, when a node originates a PTSE, the PTSE is flooded from the node horizontally and downwards through the PNNI hierarchy. A node in the lowest level of the hierarchy therefore has a copy of all the PTSEs originated by the nodes that are visible within its hierarchy, including PTSEs generated by its ancestor's nodes. For example, a PTSE originated by LGN 1 is flooded down to PGL 1 . 1 and also flooded horizontally to LGN 2 . In turn, LGN 2 floods the PTSE down to PGL 2 . 0 . PGL 1 . 1 and PGL 2 . 0 in turn flood the PTSE horizontally and downwards through the hierarchy. By way of example, suppose that node 1 . 1 . 1 generates a PTSE 1 . 1 . 1 containing an information group that cannot be summarized as it is passed through the hierarchy. An example of such an information group is an Exterior Reachable ATM address information group. PTSE 1 . 1 . 1 is flooded in the bottom peer group to PGL 1 . 1 . 2 . From this PTSE, LGN/PGL 1 . 1 generates a new PTSE 1 . 1 with the same information group. The new PTSE 1 . 1 is flooded by LGN/PGL 1 . 1 horizontally to LGN 1 . 0 and down to PGL 1 . 1 . 2 . Recursively, LGN 1 generates a new PTSE 1 with, again, the same information group. PTSE 1 is then flooded by LGN 1 horizontally to LGN 2 and down to PGL 1 . 1 where it is further flooded horizontally to LGN 1 . 0 and down to PGL 1 . 1 . 2 . The result of the flooding of non-summarizable information groups is illustrated in FIG. 2 . Specifically, FIG. 2 shows the PTSEs stored in each switch, 1 . 0 . 1 to 2 . 0 . 2 , that contains the same Exterior Reachable ATM address information group. Each switch comprises a PNNI database stored in a memory. Node 1 . 1 . 1 , the source of the non-summarizable information group, stores, in its PNNI database, three PTSEs each containing the same information group. The first stored PTSE was generated by node 1 . 1 . 1 ; the second PTSE was generated by LGN/PGL 1 . 1 ; and, the third PTSE was generated by LGN 1 .
Referring now to FIG. 3 , this shows another PNNI hierarchy comprising four levels, 64 , 72 , 88 , and 96 . Level 96 , the lowest level, comprises two peer groups, 100 and 110 . Level 88 comprises a single one peer group 120 . Likewise, level 72 comprises a single peer group 130 and level 64 , the uppermost level, comprises a single peer group 140 . Peer group 100 comprises two switches, 1 and 2 . Peer group 110 also comprises two switches, 3 and 4 . A router A is connected to switch 1 and another router B is connected to switch 2 . Likewise, a router C is connected to switch 3 and another router D is connected to switch 4 . At the lowest level 96 , switch 2 serves as the PGL in peer group 100 and switch 3 serves as the PGL in peer group 110 . At the next level 88 of the hierarchy, in peer group 120 , peer group 100 is represented by LGN 2 ′ and peer group 110 is represented by LGN 3 ′. LGN 2 ′ serves as the PGL in peer group 120 . At the next level 72 , peer group 120 is represented by LGN 2 ″ in peer group 130 . LGN 2 ″ serves as the PGL in peer group 130 . At the uppermost level 64 , peer group 130 is represented in peer group 140 by LGN 2 ′″. Nodes 2 , 2 ′, 2 ″, and 2 ′″ are all implemented in the same switch 2 . Suppose that PNNI Augmented Routing (PAR) PTSEs are originated in this hierarchy. Specifically, suppose that each router, A, B, C and D, registers a non-summarizable information group such as a PAR Service Descriptions information group with a flooding scope 64 . Each switch, 1 , 2 , 3 and 4 , therefore generates a PAR PTSE containing the PAR Service Descriptions information group of its attached router A, B, C, and D. Table 1 below shows information groups recorded in each switch at each level of the hierarchy.
TABLE 1
Switch 1
Switch 2
Switch 3
Switch 4
Level
A 1 , B 2
A 1 , B 2
C 3 , D 4
C 3 , D 4
96
Level
A 2′ , B 2′ , C 3′ , D 3′
A 2′ , B 2′ , C 3′ , D 3′
A 2′ , B 2′ , C 3′ , D 3′
A 2′ , B 2′ , C 3′ , D 3′
88
Level
A 2″ , B 2″ , C 2″ , D 2″
A 2″ , B 2″ , C 2″ , D 2″
A 2″ , B 2″ , C 2″ , D 2″
A 2″ , B 2″ , C 2″ , D 2″
72
Level
A 2′″ , B 2′″ , C 2′″ , D 2′″
A 2′″ , B 2′″ , C 2′″ , D 2′″
A 2′″ , B 2′″ , C 2′″ , D 2′″
A 2′″ , B 2′″ , C 2′″ , D 2′″
64
In Table 1 above, A 1 represents, for example, the ATM reachable address A generated by switch 1 . A 2 represents the same ATM reachable address that has been regenerated by the LGN 2 ′ in switch 2 at level 88 . Likewise, A 2″ represents the same ATM reachable address that has been regenerated by the LGN 2 ″ in switch 2 at level 72 . Similarly, A 2″ represents the same reachable ATM address that has been regenerated by the LGN 2 ′″ at level 64 . ATM reachable addresses B, C and D are similarly regenerated. In the switches, 1 , 2 , 3 , and 4 , such regeneration imposes a storage overhead, consumes bandwidth by flooding A 2′ , A 2″ and A 2′″ , and adds additional protocol processing demands.
Generally, in a conventional PNNI network of N levels, a switch that is the source of an information group must store up to N PTSEs containing the same information group if the information is not summarized with other information groups and advertised at the top of the hierarchy. An example of such a non-summarizable PTSE is a PAR PTSE. PAR PTSEs are not summarized as they are passed up through a PNNI hierarchy.
In a preferred embodiment of the present invention, there is provided a method for preventing the aforementioned regeneration of information thereby saving database memory, link bandwidth, and protocol processing. The method is based on a realization that many information groups generated by a LGN duplicate information already contained in a child node. These duplicated information groups are not necessary for PNNI functionality in nodes contained with descendent peer groups.
According to the method, a non-summarizable PTSE is allowed to flood from an originating node to neighbor nodes in the same peer group. However, the non-summarizable PTSE is prevented from flooding down into a child peer group of the originating node. Only non-summarizable PTSEs originated by a node are affected. Non-summarizable PTSEs received neighbor from nodes are still flooded down into the child peer group. Table 2 below illustrates the information groups stored in each switch at each level of the hierarchy of FIG. 3 according to this method.
TABLE 2
Switch 1
Switch 2
Switch 3
Switch 4
Level
A 1 , B 2
A 1 , B 2
C 3 , D 4
C 3 , D 4
96
Level
C 3′ , D 3′
A 2′ , B 2′ , C 3′ , D 3′
A 2′ , B 2′ , C 3′ , D 3′
A 2′ , B 2′
88
Level
A 2″ , B 2″ , C 2″ , D 2″
72
Level
A 2′″ , B 2′″ , C 2′″ , D 2′″
64
Referring to Table 2 above, switch 1 no longer receives A 2′ , B 2′ from PGL 2 because, according to the method, these are prevented from flooding down from level 88 . Similarly, switch 1 no longer receives A 2″ , B 2″ , C 2″ , D 2″ because these are prevented from flooding down from level 72 . Likewise, switch 4 no longer receives A 2′″ , B 2′″ , C 2′″ , D 2′″ because these are prevented from flooding down from level 64 . Switches 3 and 4 no longer receive A 2″ , B 2″ , C 2″ , D 2″ and A 2′″ , B 2′″ , C 2′″ , D 2′″ via PGL 3 ′ because these are prevented from flooding down from levels 72 and 64 respectively.
A mentioned earlier, one example of a non-summarizable PTSE is a PAR PTSE. Other examples include: Internal Reachable Address information groups, External Reachable Address information groups, Nodal State Parameter information groups, and Uplink information groups. In preferred embodiments of the present invention, subsequent flooding of these information groups by an LGN is confined only to peers of the LGN and does not extend into descendent peer groups via the PGL.
An example of a switch node embodying the present invention will now described with reference to FIG. 4 . FIG. 4 is a simplified schematic illustrating the main elements of such the switch node. Such a switch node may be employed in the implementation of switches 1 , 2 , 3 , and 4 . The switch node comprises control logic 200 , memory 210 and circuitry 220 comprising the interfaces and switching circuitry via which the device communicates with the rest of the network. The switch node may be a PAR-enabled device acting as a Proxy-PAR server for a connected router. The switch control logic 200 controls operation of the device generally, and implements the usual PNNI, PAR and Proxy-PAR functions. In addition, the control logic 200 performs the aforementioned method for preventing duplication of information. To facilitate performance of such a method, a look up table 230 is stored in the memory 210 . An example of such a look up table 230 is presented in Table 3 below. In operation, the control logic 200 refers to the look up table 230 to determine whether or not a PTSE created by the control logic 200 can be disseminated downwardly through the PNNI hierarchy based on the type of information contained in the PTSE. In accordance with PNNI, control logic 200 maintains a topology database in the memory 210 containing data defining the device's view of the network topology as described above, together with a PTSE repository in which PTSEs received from the network are stored until either they expire or are flushed by the usual PNNI processes.
TABLE 3
INFORMATION GROUP
PASS DOWN?
Internal Reachable ATM Address
NO
External Reachable ATM Address
NO
Nodal State Parameter
NO
Uplinks
NO
PAR Service
NO
Nodal
YES
Horizontal Link
YES
Referring now to FIG. 5 , in operation, at step 300 , the control logic 200 generates a PTSE in the memory 210 . At step 310 , the control logic checks the PTSE to identify the protocol information therein. Alternatively, the protocol information check may be performed by the control logic 200 If, at step 320 , the control logic 200 determines that the protocol information comprises Internal Reachable ATM Address, External Reachable ATM Address, Nodal State Parameter, Uplinks, or PAR Service protocol information, then, at step 330 , flooding, in other words transmittal, of the PTSE to lower levels of the network is prevented by the control logic 200 . The aforementioned look up table 230 is employed by the control logic 200 making this determination. However, if, at step 320 , the control logic determines that the protocol information comprises Nodal or Horizontal Link protocol information then, at step 340 , the control logic 200 allows flooding of the PTSE to lower levels of the network. It will be appreciated therefore that the look up table serves as a filter for preventing information group regenerated in higher levels in the PNNI network from flooding down into lower levels of the PNNI network in which the information groups are already available.
In general, the control logic 200 may be implemented in hardware or software, or a combination thereof, but will typically be implemented by a processor running software which configures the processor to perform the functions described, and suitable software will be apparent to those skilled in the art from the description herein. (Of course, while processors in the switch node may be preconfigured with appropriate software, the program code constituting such software could be supplied separately for loading in the devices to configure the processors to operate as described. Such program code could be supplied as an independent element or as an element of the program code for a number of control functions, and may be supplied embodied in a computer-readable medium such as a diskette or an electronic transmission sent to a network operator). | Described is a method for managing flow of protocol information in a node of a hierarchical network in which the protocol information is communicated between network nodes in topology state elements. The method includes checking topology state elements generated by the node to identify protocol information encapsulated therein, and selectively allowing transmittal of the topology state elements from the node to lower levels of the network based on the protocol information identified. | 7 |
CROSS REFERENCE TO RELATED APPLICATIONS
This application is a continuation-in-part of now abandoned U.S. application Ser. No. 942,472, filed on Sep. 9, 1992, which, in turn, is a continuation of now abandoned U.S. application Ser. No. 788,400, filed on Nov. 6, 1991.
BACKGROUND OF THE INVENTION
The present invention relates to circuits wherein input power is interrupted and, more particularly, to a circuit of the type described which sustains output power during said input power interruption.
A circuit for the purposes described is disclosed in U.S. Pat. No. 4,593,213 which issued to Vesce, et al on Jun. 3, 1980. Vesce discloses an electronic device comprising a switched mode power supply and a hold-up circuit. The object of the Vesce device is to transfer high voltage energy stored in a low capacitance bank to a low voltage bus, with minimum electrical disturbance, using a current-limited MOSFET switch. The power supply includes a hold-up series diode and a pulse width modulated power switch. The power supply receives primary input power. The hold-up circuit includes a high voltage energy storage capacitor bank and a hold-up transfer switch. The switch transfers high voltage energy stored in the storage capacitor bank to the low voltage bus of the power supply upon receiving an enable signal from a hold-up enable circuit. The hold-up transfer switch includes a zener diode, a resistor, a P-channel power MOSFET switch, and a diode. The Vesce device wastes energy in the disclosed switch because the switch is not operated in its saturation region. The Vesce device also requires an extra diode which further increases the losses in the circuit.
SUMMARY OF THE INVENTION
The present invention contemplates a circuit for sustaining output power during input power interruption. The circuit takes advantage of the fact that the energy stored in a capacitor is equal to one-half of the capacitance of the capacitor multiplied by the square of the voltage across the capacitor to achieve the desired result with a physically smaller energy storage capacitor. The circuit includes an N-channel power MOSFET switch, a voltage blocking diode, an energy storage capacitor, a voltage sensing circuit and a capacitor/diode network to provide a constant MOSFET drive. The output of the circuit is applied to a DC/DC converter section of a power supply.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an electrical schematic diagram illustrating one embodiment of the present invention.
FIG. 2 is an electrical schematic diagram illustrating an alternate embodiment of the present invention.
FIG. 3 is a graphical representation illustrating the results of a simulation of one embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
With reference to FIG. 1, under normal operating conditions, an aircraft's auxiliary power unit (APU) provides, for example, a 28 volt DC voltage V IN at a power input terminal 2 in the range of V IN MIN at the low end, V IN MAX at the high end and V IN at the nominal level. Normally, V IN is larger than V' IN , which is the DC voltage after a blocking diode 4, by the forward voltage drop across blocking diode 4. V' IN is larger than an avalanche voltage V Z across a zener diode 6, and a voltage V C across an energy storage capacitor 8 is larger than V IN . In this regard, it will be appreciated that the energy stored in a capacitor is equal to one-half of the capacitance of the capacitor times the square of the voltage across the capacitor. The physical size of a capacitor is generally proportional to its capacitance times a DC voltage rating product. Thus, to maximize the stored energy of a capacitor while minimizing its physical size, the voltage across the capacitor is maximized.
Under these conditions, an NPN bipolar transistor 10, located within an input power sensing circuit 11, is kept in the "ON" state via a divider circuit including resistors 14 and 16. The collector (C) of transistor 10 is then at a potential V X , where V X =V Z +V CE . V CE is the collector (C) to emitter (E) voltage across transistor 10. The gate terminal (G) of an N channel enhancement MOSFET 12 is also at the V X potential and the source terminal (S) of the MOSFET is at the V' IN potential.
The gate-to-source voltage across MOSFET 12 is equal to V X minus V' IN , but since V' IN is larger than V X , the gate-to-source voltage is negative and MOSFET 12 is in the "OFF" state. Energy storage capacitor 8 is kept charged to a potential +V C , the steady state charge.
This steady state charge is provided via circuits 20 and 22. Circuit 20 is a DC/DC converter circuit and circuit 22 is a voltage doubler/snubber circuit.
Circuit 20 includes basic flyback DC/DC converter circuitry, having a primary winding 23 and three secondary windings 24, 26 and 28, connected to rectifier diodes 30, 32 and 34, respectively. Two of the windings such as 24 and 26 are used to generate output voltages, while the third winding 28 is used as a bootstrap to provide a voltage V CC to a pulse width modulator (PWM) 36 during normal operation, i.e. after the DC/DC converter starts operating, overriding V cc start-up.
Output voltage V O is the primary regulated output power. Feedback is accomplished via resistors 38 and 40. Resistor 40 is connected to diode 32 via a filter 39. For purposes of simplification, the frequency compensation of the internal error amplifier of PWM 36 has not been shown, although the same will be understood by those skilled in the art.
PWM 36 drives a switching MOSFET 42 directly. A start-up V CC circuit, which can be any arrangement for generating voltage V CC from V' IN to start PWM 36 during power-up, is designated by the numeral 44. Secondary winding 28 of circuit 20 and its associated rectifier diode 34 are included to override the start-up V CC , since circuits for this purpose are often too inefficient to provide V CC during normal operation. Resistor 46 and capacitor 48 provide feedforward to the internal error amplifier of PWM 36 to minimize output transients during power interrupts when V' IN jumps from V IN (minus a diode drop) to V C as will be hereinafter explained and as particularly illustrated in FIG. 3.
Circuit 22 is referred to as a voltage doubler/snubber circuit because it snubs the peak voltages that occur when switching current through an inductor, and virtually doubles the switched voltage that appears at gate (G) of MOSFET 42. Snubbing is often necessary in switched converters to insure that the maximum allowable drain-to-source voltage of the MOSFET is not exceeded. Snubbing of the drain voltage of MOSFET 42 is achieved mainly by a diode 50 and a capacitor 52, although it will be appreciated that all components in circuit 22 are involved to some degree in the snubbing action.
As to the voltage "doubling" action, the switched voltage that appears at the drain (D) of MOSFET 42 is rectified by diode 50 and a DC voltage is created across capacitor 52. The voltage at the cathode of a diode 54 is a superposition of the voltage across capacitor 52 (minus a diode drop) and the AC coupled voltage at the drain (D) of MOSFET 42. A capacitor 55 is connected in parallel with diodes 54 and 50.
Storage capacitor 8 charges to the peak voltage at the cathode of diode 54 via resistor 56 and diode 58. The energy stored in capacitor 8 is the energy used to supply the input to DC/DC converter circuit 20 during a primary power interruption. Therefore, the voltage doubler/snubber circuit snubs the drain voltage of MOSFET 42 while peak charging storage capacitor 8 to a voltage above V IN .
The current through a resistor 60 is determined by +V C minus V X divided by the resistance of resistor 60.
Power is normally provided to DC/DC converter 20 by blocking diode 4. Upon a power interruption, divider circuit 14/16 senses that V IN is falling below V IN MIN and allows transistor 10 to turn OFF. The collector (C) of transistor 10 goes to a high impedance mode. As gate (G) of MOSFET 12 is released from the V X potential, current starts to flow from +V C through resistor 60, charging the gate (G) to source (S) capacitance of MOSFET 12. As the gate to source voltage approaches a threshold, MOSFET 12 starts to partially conduct and dumps the energy stored in energy storage capacitor 8. If said gate to source voltage tries to go higher than the threshold, MOSFET 12 conducts more, therefore reducing the drain to source voltage and, as a consequence, reducing the gate to source voltage, which in turn causes MOSFET 12 to conduct less. The net effect is that MOSFET 12 conducts just enough to maintain its gate to source voltage equal to the threshold. This limits the amount of current which is discharged from energy storage capacitor 8.
The loss of input power is determined by circuit 11 which includes divider circuit 14/16, transistor 10 and zener diode 6. An input capacitor 62 provides filtering to the switching currents of DC/DC converter 20. A return for the DC voltage supplied by the aircraft's auxiliary power unit is at a return terminal 64.
The configuration of the invention shown and described with reference to FIG. 1 is such that when MOSFET 12 is partially conducting, it is dissipating power that otherwise would be transferred to the output by DC/DC converter 20. Therefore, energy storage capacitor 8 has to be designed to store more energy than necessary to account for the losses incurred by MOSFET 12.
FIG. 2 illustrates an embodiment of the invention which avoids this power dissipation.
With reference then to FIG. 2, wherein components corresponding to those in FIG. 1 carry corresponding numerical designations, power is provided to DC/DC converter 20 by means of blocking diode 4 and the circuit of FIG. 2 operates in a manner such as the circuit of FIG. 1 as heretofore described. In order to overcome the aforementioned power dissipation, a capacitor 66 and a diode 68 are utilized to modify the gate to source voltage of MOSFET 12. Capacitor 66 is allowed to charge to the difference between +V C minus the voltage drop across diode 68 minus V' IN .
FIG. 3 illustrates the results of a simulation of a preferred embodiment of the present invention.
Curve D tracks input power (V IN ) which enters the circuit of the invention at power input 2.
Curve C shows the minimum V IN level (V IN MIN) required by DC/DC converter 20 in order to provide regulated outputs.
Curve B is output V O and indicates that there is no output power interruption prior to or during the input power interruption. Curve B also indicates that the output power drops only after V IN (curve A) falls below V IN MIN (Curve C).
Curve A indicates that as MOSFET 12 is turned fully ON, V' IN jumps from its voltage prior to the input power interruption to voltage +V C stored in energy storage capacitor 8.
With the above description of the invention in mind, reference is made to the claims appended hereto for a definition of the scope of the invention. | A circuit takes advantage of the voltage square times capacitance function of a capacitor to sustain output power during input power interruption with a smaller energy storage capacitor. The circuit comprises an N channel power MOSFET switch, a voltage blocking diode, an energy storage capacitor, a voltage sensing circuit and a capacitor/diode network to provide a constant MOSFET drive. | 8 |
This application claims priority from U.S. Provisional Application Serial No. 60/141,171, filed Jun. 25, 1999, which is incorporated herein by reference.
BACKGROUND
1. Technical Field
The present disclosure relates to an access opening closure device for allowing articles to pass through an otherwise impervious wall. More specifically, the present disclosure relates to an access opening closure device for use in prisons and hospital psychiatric wards which allows an article to be passed through a cell or hospital room door without exposing a guard or hospital attendant to possible injury or battery by the prisoner or patient.
2. Background of Related Art
Prison cell and hospital room doors for confining dangerous inmates or patients which are fitted with an access opening to allow passage of food or medication without the necessity of opening the locked door are well known. The access opening may also be used to handcuff an inmate before unlocking the door. Typically, the access opening is small in relation to the door and is covered by a portal which may be closed to close the access opening. One problem associated with the above-described access opening/portal arrangement is that once the portal is opened, the confined inmate or patient has direct access to the area outside the confined space. Due to the violent nature of some confined inmates and/or patients, prison guards and hospital attendants are exposed to possible danger from the confined inmate or patient when direct access is available.
Accordingly, what is needed is an access opening closure device of simple construction which can be used in association with existing doors having access openings and is operable to allow passage of articles through the access opening without allowing an inmate or patient direct access from the confined space to the area outside of the confined space.
SUMMARY
An access opening closure device is provided for use in prisons, hospital psychiatric wards and the like is disclosed. The closure device includes a housing defining a receptacle, an access door and a top cover. The top cover is preferably formed from a transparent material and is movably supported on the housing to open or close a top opening in the housing. The access door is preferably formed from stainless steel and is movably supported on the housing to open or close a rear opening in the housing. A bracket assembly is secured to the housing about the rear opening. The bracket assembly is adapted to secure the housing about an access opening in a door, e.g., a prison cell door. The device also includes three locks. A first lock is positioned to retain the top cover in a closed position. A second lock is positioned to retain the access door in its closed position and a third lock is positioned to retain the access door in its open position.
BRIEF DESCRIPTION OF THE DRAWINGS
Various preferred embodiments of the access opening closure device are described herein with reference to the drawings, wherein:
FIG. 1 is a perspective view of one embodiment of the presently disclosed access opening closure device;
FIG. 2 is a perspective view of the access opening closure device shown in FIG. 1 with the top cover in its open position and its access door in its closed position;
FIG. 3 is a partial cross-sectional view taken along section lines 3 — 3 of FIG. 1;
FIG. 4 is a perspective view of the access opening closure device shown in FIG. 1 with the top cover in a closed position and the access door in an open position;
FIG. 5 is a partial cutaway view taken along section lines 5 — 5 of FIG. 4; and
FIG. 6 is a perspective view of another embodiment of the present disclosed access opening closure device.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
Preferred embodiments of the presently disclosed access opening closure device will now be described in detail with reference to the drawings, in which like reference numerals designate identical or corresponding elements in each of the several views.
FIGS. 1 and 2, illustrate an access opening closure device, shown generally as 10 . Briefly, closure device 10 includes a housing 12 , an access door 14 and a top cover 16 . Housing 12 has a bottom wall 18 , a pair of side walls 20 and 22 and a front wall 24 which defines a receptacle 25 for receiving food, medication or the like. A plurality of drain holes 29 (FIG. 2) are formed through the bottom wall 18 to allow fluid to drain therefrom. Side walls 20 and 22 have a height that increases from front end 26 to rear end 28 of housing 12 . Alternately, the side walls can be rectangular. In extreme cases, when a prisoner or patient must be subdued before the guard enters the cell, the reduced height of front end 26 compared to rear end 28 of housing 12 enables the guard to spray a subduing agent, such as pepper spray or mace, directly into the cell. Preferably, housing 12 is constructed from stainless steel, although other materials having the requisite strength requirements can also be used.
Referring also to FIG. 3, top cover 16 is pivotably attached to the top of front wall 24 via hinge assembly 29 . Preferably, hinge assembly 29 is fastened to cover 16 and front wall 24 by screws 27 . However, other fastening techniques may also be used including adhesives, welding, etc. Top cover 16 is pivotable from a first closed position enclosing housing 12 to a second open position uncovering housing 12 . Preferably, cover 16 is constructed from a durable, transparent material such as Lexan® which permits viewing of the contents of receptacle 25 when top cover 16 is in the closed position. Alternately, other materials having the requisite strength requirements can also be used including stainless steel, aluminum or fire safe material having the requisite strength requirements.
A series of brackets including a top bracket 30 , a side bracket 32 and a bottom bracket 34 are secured to the rear end of housing 12 by welding. Alternately, the series of brackets can be secured to housing 12 using other known fastening procedures. Each of the brackets includes a smooth concavity 33 for slidably receiving access door 14 . The concavities formed in top and bottom brackets 30 and 34 define a guide track along which door 14 may be slid between open and closed positions. As illustrated in FIGS. 1 and 2, the guide track is formed in top and bottom brackets 30 and 32 at a position adjacent the back side 31 of the brackets which is to be positioned against the prison cell or hospital room door 35 . By forming the guide track in this manner, access door 14 can be positioned close to door 35 while retaining the required thickness for strength. Side bracket 32 also includes a concavity (not shown) into which the forward end 36 of door 14 is positioned when door 14 is closed. Each of the brackets also includes a series of holes dimensioned to receive screws. The screws facilitate securement of the housing about an access port in door 35 .
Access door 14 is slidably positioned along the guide track formed between top and bottom brackets 30 and 34 . Door 14 includes a handle 40 to facilitate opening and closing of the door. Preferably, the top and bottom edges 37 and 38 of door 14 are radiused to permit door 14 to slide freely along the guide track. Door 14 is movable from a closed to an open position to permit access into housing 12 from within the confined space. A stop 41 (FIG. 2) is fastened to one side of access door 14 . Stop 41 is positioned to engage side wall 22 when access door 14 is in the open position to prevent door 14 from sliding out of the guide track. Preferably, sliding door 14 is
A pair of locks 42 and 44 are secured adjacent to access door 14 . Preferably, locks 42 and 44 are secured to top bracket 30 via screws. Alternately, locks 42 and 44 can be secured to door 35 and/or other fastening techniques may be used to secure the locks in place. Referring to FIG. 4, each lock includes a spring biased projection 54 and 55 which is urged downwardly towards the bottom frame. A catch 56 is secured to access door 14 and is positioned to engage projection 54 of lock 42 . When projection 54 is positioned within catch 56 , access door 14 is locked in a closed position. Projection 54 of lock 42 can be lifted from catch 56 by rotating key 58 .
Lock 44 is positioned above top edge 37 of access door 14 . A pair of recesses 48 and 50 formed in top edge 37 are positioned to receive projection 55 of lock 44 . When projection 55 is biased into recess 48 , access door 14 is locked in an open position. When projection 55 is biased into recess 50 , access door 14 is locked in a half-open position. The combination of locks 42 and 44 prevents access door 14 from being slammed between its open and closed positions.
A lock 66 is also provided on top cover 16 . Lock 66 includes a spring biased projection 68 which is receivable in a catch 20 to lock top cover 16 in the closed position. Catch 70 can be secured to top bracket 30 . Alternately, catch 70 can be secured to other support structures, such as door 35 .
In use, access opening closure device 10 is secured about an access opening in a door 35 on a secure side of the door, e.g., on the side of a prison cell door external of the cell. In the closed position, access door 14 and top cover 16 are closed (FIG. 1 ). When it is desired to provide the confined person with some item, such as a lunch tray 60 , cover 16 is pivoted to open the top of housing 12 . To pivot cover 16 , lock door 14 is slid open by manually rotating key 58 and pulling handle 40 (FIG. 4 ). It is noted that in order to slide access door 14 to the fully open position, projection 55 of lock 44 must be manually lifted over recess 50 . The confined person now has access to the interior of housing 12 but the interior of housing 12 is enclosed with respect to the passageway in front of cell door 35 . Thus, persons in the passageway are protected from any debris the confined person may attempt to throw through the access opening. With sliding door 14 in the open position and cover 16 in the closed position, the lunch tray or other item can be left in housing 12 for the confined person to retrieve at his or her convenience.
Access opening closure device 10 may also be used to handcuff a prisoner before releasing the prisoner from the cell. To handcuff a prisoner, access door 14 need only be opened to its halfway point with projection 55 of lock 44 positioned in recess 50 of door 14 . After the prisoner places his hands through the access opening into receptacle 25 , top cover 16 can be pivoted open to facilitate the placing of the handcuffs on the prisoner. It is noted that, with top cover 16 pivoted in front of a prison guard, top cover 16 acts as a shield for the guard.
Referring to FIG. 5, a slot 62 is formed in side bracket 32 adjacent the concavity formed in bottom bracket 34 . Slot 62 allows any debris positioned on the guide track in concavity 35 , when access door 14 is opened, to be pushed from the end of the guide track. Thus, access door 14 will not be prevented from closing by placing debris on the guide track.
FIG. 6 illustrates an alternate embodiment of the access opening closure device shown generally as 100 . Closure device 100 is substantially identical to closure device 10 except that top cover 116 is slidable between open and closed positions along a track 113 formed about the top of housing 112 .
It will be understood that various modifications may be made to the embodiments disclosed herein. For example, access door 14 need not slide horizontally but rather may slide vertically. Further, the dimensions of the access opening closure device can be varied to accommodate any size access opening. Moreover, the access opening closure device is not limited for use on hospital room and prison cell doors but rather may be used in other areas such as bank teller stations. Therefore, the above description should not be construed as limiting, but merely as exemplifications of preferred embodiments. Those skilled in the art will envision other modifications within the scope and spirit of the claims appended hereto. | An access opening closure device is provided for enabling passage of food or medication into a confined spaced without providing direct access from within the confined space to outside of the confined space. The device includes a housing defining a receptacle, an access door and a top cover. The top cover and the access door are independently movable between open and closed positions to provide access to within the receptacle. | 4 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a method for probing a specific site on the inner surface of a luminal organ within a body cavity, and to a method for holding the same luminal organ, during laparotomy or laparoscopic surgery.
2. Description of Related Art
A dot inking method employing India ink is carried out as a method for identifying microscopic lesions occurring on the inside of a luminal organ, such as the stomach or large intestine, during surgery via laparoscopy or laparotomy. In this dot inking method, India ink, which serves as a marker near the lesion, is injected from inside the luminal organ, to facilitate identification of the location of the lesion during either direct or indirect gross visualization of the outside of the luminal organ. A surgical method in which a lesion site occurring on the inside of the stomach is resected will now be explained as one example of this dot inking method.
First, several days to several weeks prior to the surgery, dot inking, which will serve as a marker during the resection, is performed near the site of the lesion. Specifically, an endoscope is inserted into the patient via the oral cavity, a needle is used to pierce the stomach wall from the inside near the lesion site, and India ink is injected. The injected India ink spreads out over the stomach wall, and assists in the direct or indirect gross confirmation of the lesion at the time of resection. During this procedure, care must be exercised to inject the ink to just the right depth to enable visual confirmation of the location of the spread India ink when viewing the stomach from the outside, without sticking the end of the needle completely through the stomach wall. If the needle penetrates through the stomach wall, then not only does the site of the lesion become unclear, but other internal organs may become coated with the India ink, resulting in a situation in which it is not possible to continue with surgery. Further, if the India ink cannot be injected so as to be visible from outside the stomach, then it is not possible to discern the lesion site, which can result in the all or part of the lesion being left behind following resection. In other words, the problem with this dot inking method is that it requires a high level of expertise to adjust the depth to which the needle is pierced, so that the dot inking can be carried out reliably.
Next, a conventional method for holding the lesion site as required during surgery will be explained. During surgery, the surgeon first searches for the location of the dot inking while using a laparoscope to visualize the outside of the stomach. Once the position of the dot inking is found, the positional relationship between the dot inking and the lesion site is taken into consideration, and metallic holding forceps are employed to hold the stomach and apply traction in a manner that will enable resection. Then, at a location on the stomach that is separated away from the area being held, a portion of the stomach (that includes the lesion site) is cut out using a procedure tool such as an automatic suturing device. In order that none of the lesion site is left behind in this method, it is necessary that the surgeon separate the lesion site and the holding position in this method. Additionally, since the surgeon must simultaneously carry out confirmation of the lesion site and the operation of holding the lesion, a high level of expertise is demanded.
As another method for resecting the stomach, there is a method in which, instead of using metallic holding forceps to hold the stomach in the vicinity of the lesion, the area of the stomach near the lesion is instead suspended using a thin metal rod in which a wire has been attached to the center, and the suspended area is resected. More specifically, this metal rod with attached wire is passed through the stomach wall by piercing the outside of the stomach with the rod in the vicinity of the lesion, which has been inked. Next, the wire attached to the metal rod is introduced to the outside of the abdominal cavity. Then, by applying traction from outside the body on the wire attached to the metal rod, the lesion site on the stomach can be suspended, and the lesion site, which is now easily resectable as a result of being suspended, is resected using an automatic incising and suturing device. This method requires a high level of skill to perform the operation of piercing the metal rod with the attached wire near the lesion from a position outside the body.
SUMMARY OF THE INVENTION
The present invention provides a method for probing a luminal organ that is provided with the steps of:
pre-anchoring a magnetic body at a specific position inside a luminal organ; and
bringing a magnet close to the outside of the luminal organ, such that the magnetic body is attracted to the magnet, along with the body tissue of the luminal organ.
The present invention provides a method for holding a luminal organ that is provided with the steps of:
pre-anchoring a magnetic body at a specific position inside a luminal organ; and
bringing a magnet close to the outside of the luminal organ, such that the magnetic body is pulled and held to the magnet, along with the body tissue of the luminal organ.
The present invention provides a method for changing between applications that is provided with a step for switching between the above-described probing method for a luminal organ and the above-described holding method for a luminal organ by adjusting the strength of the magnetic force of the magnet.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view showing a magnetic forceps and anchoring device employed in the surgery according to the present invention.
FIG. 2 is a cross-sectional view showing an essential element of the magnetic forceps.
FIG. 3 is a view showing the position of the penetrating holes that are made in the abdomen of the patient during the surgery according to the present invention.
FIG. 4 is a phase diagram showing a process in the surgery for partial resection of the stomach according to the present invention.
FIG. 5 is a phase diagram showing a process in the surgery for partial resection of the stomach according to the present invention.
FIG. 6 is a phase diagram showing a process in the surgery for partial resection of the stomach according to the present invention.
FIG. 7 is a phase diagram showing a process in the surgery for partial resection of the stomach according to the present invention.
FIG. 8 is a phase diagram showing a process in the surgery for partial resection of the stomach according to the present invention.
FIG. 9 is a phase diagram showing a different process from the above in the surgery for partial resection of the stomach according to the present invention.
FIG. 10 is a phase diagram showing a process in the surgery for partial resection of the large intestine according to the present invention.
FIG. 11 is a phase diagram showing a process in the surgery for partial resection of the large intestine according to the present invention.
FIG. 12 is a phase diagram showing a process in the surgery for partial resection of the large intestine according to the present invention.
FIG. 13 is a phase diagram showing a process in the surgery for partial resection of the large intestine according to the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Embodiment 1
The surgery to partially resect the stomach under laparoscopy will be explained in this embodiment with reference to FIGS. 1 through 9 .
The instruments employed in the surgery will be explained first. FIGS. 1 and 2 show a magnetic forceps 1 and an anchoring device 2 , which is anchored on the inside of the stomach, that are employed in the partial resection of the stomach in this embodiment. Magnetic forceps 1 is provided with an inserted part 10 which is inserted into the abdominal cavity, a magnet 11 for attracting and contacting anchoring device 2 , and an operating part 12 for operating magnet 11 . Inserted part 10 is in the form of a rigid narrow tube, the end of which is covered by fixing in place a cover 10 a.
Magnet 11 is cylindrical in shape and has an outer diameter that is slightly smaller than the inner diameter of inserted part 10 . One end surface thereof forms the N pole, and the other end surface thereof forms the S pole. The magnetic line of force magnet 11 acts to pass through both end surfaces. Magnet 11 is seated inside of the end of inserted part 10 , and is disposed so as to move along the longitudinal direction of inserted part 10 . Operating part 12 is provided at the base end of inserted part 10 . Operating part 12 is connected to magnet 11 via a rod 12 a that is disposed inside inserted part 10 .
By manipulating operating part 12 of magnetic forceps 1 , it is possible to adjust the strength of the magnetic force generated at the end of inserted part 10 . Specifically, when rod 12 a is pulled out from inserted part 10 by manually manipulating operating part 12 , magnet 11 is moved in a direction away from cover 10 a on the inside of inserted part 10 . In this case, the magnetic flux density at the end of magnetic forceps 1 decreases, and the magnetic force generated at the end of inserted part 10 weakens. On the other hand, by pushing rod 12 a into inserted part 10 , magnet 11 is moved in the direction toward lid 10 a on the inside of inserted part 10 , causing the magnetic flux density at the end of magnetic forceps 1 to increase, and the magnetic force generated at the end of inserted part 10 to intensify.
Anchoring device 2 is provided with a magnet (magnetic body) 21 and a clip 20 that holds and is fixed in place to the mucosa on the inside of the stomach. Magnet 21 is connected to clip 20 via thread 22 , and is coated with a material such as titanium or silicon that is not harmful to the body.
Magnetic forceps 1 is used in combination with a rigid sheath 3 . Sheath 3 is cylindrical in form, and has an inner diameter that is slightly larger than the outer diameter of inserted part 10 . Magnetic forceps 1 is inserted into the abdominal cavity while disposed inside sheath 3 , and is employed in a state where the end of magnetic forceps 1 (i.e., the end of inserted part 10 ) projects out from sheath 3 .
The surgical sequence will now be explained.
First, several days to several weeks prior to the surgery, anchoring device 2 is anchored in the stomach wall near the site where a lesion has occurred on the inside of the stomach. Specifically, an endoscope is inserted into the patient via the oral cavity, anchoring device 2 is introduced to the inside of the stomach by passing it through the inserted part of the endoscope, and the stomach wall near the lesion site is grabbed and held in place by clip 20 . In order to prevent clip 20 from falling off, care is exercised to firmly grab the mucosa of the stomach wall with clip 20 . Further, in order to appropriately resect the lesion during surgery, the positional relationship between the lesion site and the site where anchoring device 2 is anchored is recorded.
Next, the actual surgical sequence will be described.
The patient is placed in the supine position, and a laparoscopic trocar (an instrument used for introducing surgical instruments into the abdominal cavity) is inserted by piercing the abdominal wall at a site flanking the umbilicus. Carbon dioxide gas is injected into the abdominal cavity via the laparoscopic trocar, to insufflate the abdominal cavity and secure the surgical space. The position of insertion of the laparoscopic trocar is indicated by symbol A in FIG. 3 . In addition, two trocars for the forceps and one trocar for procedure tools are each inserted by piercing through the abdominal wall. The positions for insertion of the trocars for the forceps are indicated by symbols B and C in FIG. 3 , and the position of insertion of the trocar for the procedure tools is indicated by symbol D in the same figure.
The laparoscope is inserted into the abdominal cavity via the laparoscopic trocar. A television camera is connected to the laparoscope. The view from the endoscope, which is captured on this television camera, is projected on a television monitor that is disposed inside the operating room. The surgeon views the inside of the abdominal cavity by watching the image displayed on the television monitor. Further, grasping forceps and the procedure tools are inserted into the abdominal cavity via the other trocars, and peeling of the serosal membrane surrounding the stomach and duodenum, cutting of vessels and removal of lymph nodes are performed.
The duodenum is detached using a cutting tool while holding the lower portion of the stomach using the grasping forceps.
Sheath 3 is inserted into the abdominal cavity via the forceps trocar. Next, as shown in FIG. 4 , magnetic forceps 1 is inserted into the abdominal cavity through sheath 3 . At this time, the magnetic force of magnetic forceps 1 is weak. When the end of magnetic forceps 1 is brought close to the outside of stomach S, the magnetic force of magnetic forceps 1 intensifies and, as shown in FIG. 5 , magnet 21 of anchoring device 2 is attracted toward the end of magnetic forceps 1 . As a result, the stomach wall where magnet 21 is anchored deforms so as to be lifted up toward the outside. The surgeon observes the change in the shape of the stomach wall from the image displayed on the television monitor, and acknowledges this site where anchoring device 2 is anchored. Then, based on the record of the positional relationship between lesion site L and the location at which anchoring device 2 is anchored, the surgeon estimates the position of lesion site L correctly. While the surgeon estimates the location of the lesion site L, the magnetic force of magnetic forceps 1 is increased, magnet 21 is pulled and held to the end of magnetic forceps 1 along with the stomach wall where lesion L has occurred, and the stomach wall is held with magnetic forceps 1 .
While holding the stomach wall with magnetic forceps 1 , another area of the stomach wall is held using grasping forceps 4 , which were inserted into the abdominal cavity via another forceps trocar, as shown in FIG. 6 . Stomach S is then held in two places using magnetic forceps 1 and grasping forceps 4 , and an automatic suturing device 5 is employed to incise and suture stomach S, as shown in FIG. 7 . The incised area is closer to the cardia than the areas being held by magnetic forceps 1 and grasping forceps 4 , i.e., closer than the part that includes lesion site L, and lesion site L is included in this detached portion of the stomach.
Grasping forceps 4 is released from stomach S, and the detached portion of the stomach is pulled out from the abdominal cavity along with magnetic forceps 1 . The penetrating hole though which magnetic forceps 1 was passed is enlarged, etc., to pull the detached stomach out of the abdominal cavity.
In place of magnetic forceps 1 , a regular grasping forceps is inserted into the abdominal cavity, and two grasping forceps are used to hold the remaining stomach and the duodenum. As shown in FIG. 8 , only a portion of the sutured part of the remaining stomach S is then resected, and this resected part and the duodenum Du are anastomosed using an automatic anastomosing device. Note that it is also acceptable for the surgeon to perform the suturing, rather than using a procedure tool such as an automatic anastomosing device.
Once anastomosis is complete, the laparoscope, grasping forceps and other instruments are removed, a drain tube is passed through the penetrating hole that was used to pass the grasping forceps, the other penetrating holes are sutured closed, and the surgery is completed.
In the above-described surgery for partial resection of the stomach under laparoscopy, when the end of the magnetic forceps is brought close to the outside of the stomach, magnet 21 is attracted to the end of magnetic forceps 1 , and the stomach wall in which magnet 21 is anchored is deformed so as to be lifted up toward the outside. As a result, the surgeon can correctly estimate the site where anchoring device 2 is fixed, i.e., the position of the lesion site, easily and quickly, through the television monitor.
When the magnetic force of magnetic forceps 1 is increased, since magnet 21 is pulled and held to the end of magnetic forceps 1 along with the stomach wall, it is possible to hold the stomach wall which is difficult to grasp with the grasping forceps, etc., easily and correctly, without causing injury.
By using magnetic forceps 1 in this way, since the surgical time is shortened, and there is no injury to the stomach wall or other body tissues, it is possible to reduce the surgical stress on the patient.
In this embodiment, the resected stomach, i.e., the portion of the stomach that includes the lesion, was removed prior to anastamosing stomach S and duodenum Du, however, it is also acceptable to remove this portion of the stomach after the anastamosis. In this case, after resecting the stomach, operating part 12 is manipulated to decrease the magnetic force of magnetic forceps 1 , and the resected stomach is at once released from magnetic forceps 1 . A regular grasping forceps is then inserted into the abdominal cavity in place of magnet forceps 1 , and the stomach and duodenum are anastomosed in the same manner as above. Once the anastomosis is complete, magnetic forceps 1 is reinserted into the abdomen cavity in place of the regular grasping forceps. The end of magnetic forceps 1 is brought near the stomach (resected stomach) which was temporarily placed within the abdominal cavity, and the stomach is pulled and held to the end of magnetic forceps 1 as a result of the increase in magnetic force. The resected stomach is then pulled out along with magnetic forceps 1 , and is withdrawn from the abdominal cavity by enlarging the penetrating hole through which the magnetic forceps 1 was passed.
In this embodiment, surgery to join the duodenum with the remaining portion of the stomach left after resection of the lower part of the stomach was explained. However, if the lesion site is not so large, then it is also acceptable to resect only the stomach wall where the lesion occurred, within given margins, as shown in FIG. 9 .
Embodiment 2
In this embodiment, the surgery for partial resection of the large intestine will be explained with reference to FIGS. 10 through 13 .
First, several days to several weeks prior to the surgery, anchoring device 2 is anchored in the intestinal wall near the site where a lesion has occurred on the inside of the large intestine. Specifically, an endoscope is inserted via the anus, anchoring device 2 is introduced to the inside of the large intestine by passing it through the inserted part of the endoscope, and the intestinal wall near the lesion site is grabbed and held by clip 20 . In order to prevent clip 20 from falling off, care is exercised to ensure that clip 20 firmly grabs the mucosa of the intestinal wall. Further, in order to appropriately resect the lesion during surgery, the positional relationship between the lesion site and the site where anchoring device 2 is anchored is recognized.
Next, the actual surgical sequence will be explained.
A laparoscope is inserted into the patient's abdominal cavity. The surgeon views the inside of the abdominal cavity by watching the image displayed on the television monitor. Further, grasping forceps and procedure tools are inserted into the abdominal cavity. Peeling of the serosal membrane surrounding the large intestine, cutting of vessels and removal of lymph nodes are carried out.
As shown in FIG. 10 , sheath 3 is inserted into the abdominal cavity, and magnetic forceps 1 is then inserted into the abdominal cavity through sheath 3 . At this time, the magnetic force of magnetic forceps 1 is set to be weak. When the end of magnetic forceps 1 is brought close to the outside of large intestine I, magnet 21 of anchoring device 2 is attracted to the end of magnetic forceps 1 . As a result, the intestinal wall in which magnet 21 is anchored is deformed so as to be lifted up toward the outside. The surgeon observes the change in the shape of the intestinal wall from the image displayed on the television monitor, and acknowledges the site where anchoring device 2 is anchored. Based on the record of the positional relationship between lesion site L and the location at which anchoring device 2 is anchored, the surgeon estimates the position of lesion site L correctly. While the surgeon estimates the location of lesion site L, the magnetic force of magnetic forceps 1 is increased, magnet 21 is pulled and held to the end of magnetic forceps 1 along with the intestinal wall where lesion site L has occurred, and the intestinal wall is held with magnetic forceps 1 .
As shown in FIG. 11 , while holding the intestinal wall with magnetic forceps 1 , a part of the large intestine I that is closer to the anus than lesion site L is grasped using another grasping forceps 4 that was inserted into the abdominal cavity. Large intestine I is then detached using cutting tool 6 , while being held in two places by magnetic forceps 1 and grasping forceps 4 . The detached area is closer to the anus than the area being held by magnetic forceps 1 , i.e., the area including lesion site L.
Next, while using magnetic forceps 1 to hold the intestinal wall where lesion site L has occurred, a part of the large intestine I that is closer to the mouth than lesion site L is held using grasping forceps 4 as shown in FIG. 12 . The large intestine I is then detached using cutting tool 6 while being held at the two sites by magnetic forceps 1 and grasping forceps 4 . The detached site is closer to the mouth than the part being held by magnetic forceps 1 , i.e., the part including lesion site L.
Grasping forceps 4 is released from large intestine I, the resected large intestine is pulled out from the abdominal cavity along with magnetic forceps 1 , and withdrawn from the abdominal cavity by widening the penetrating hole through which magnetic forceps 1 was passed. Note that the resected large intestine can also be withdrawn after anastamosis of the remaining intestine, in the same gist as described in the preceding first embodiment.
A regular grasping forceps is inserted into the abdominal cavity in place of magnetic forceps 1 , the large intestine I on the oral side is held by one of the grasping forceps 4 , and traction is applied toward the anus. Similarly, the large intestine I on the anal side is held by the other grasping forceps, and traction is applied toward the oral side. As shown in FIG. 13 , the two pieces of large intestine held by grasping forceps 4 are then anastamosed using an automatic anastomosing device. Note that it is also acceptable for the surgeon to perform the suturing, rather than using a procedure tool such as an automatic anastomosing device.
Once the anastomosis is complete, the laparoscope, grasping forceps and other instruments are removed, a drain tube is passed through the penetrating hole that was used to pass the grasping forceps, the other penetrating holes are sutured closed, and the surgery is completed.
In the above-described surgery for partial resection of the large intestine under laparoscopy, the surgeon can correctly estimate the position of the lesion site, easily and quickly, through the television monitor.
When the magnetic force of magnetic forceps 1 is increased, since magnet 21 is adsorbed pulled and held to the end of magnetic forceps 1 along with the large intestine, it is possible to hold the large intestine which is difficult to grasp with the grasping forceps, etc., easily and correctly, without causing injury.
The preceding first and second embodiments employed a magnetic forceps 1 with a design for adjusting the strength of the magnetic force by moving a magnet 11 closer to or further away from the end of inserted part 10 . However, it is also acceptable to employ a magnetic forceps using an electromagnet that is capable of electrically adjusting the magnetic force.
Instead of adjusting the magnetic force, it is also acceptable to prepare a plurality of magnetic forceps having different magnetic strengths. In this case, a forceps having a weak magnetic force is inserted into the abdominal cavity when acknowledging the lesion site, and is exchanged for a forceps having a strong magnetic force when holding the luminal organ where a lesion has occurred.
Surgery to resect a portion of the stomach or large intestine under laparoscopy was explained in the first and second embodiments above. However, these methods for probing and holding a luminal organ of the present invention are not limited to application under laparoscopy. Rather, these methods are also extremely effective and provide low stress on the patient in the case where probing or holding a luminal organ such as the stomach or large intestine during abdominal surgery. In this case, the holding position is not absolutely restricted to the lesion site or areas in the vicinity thereof. Rather, the aforementioned site may be anywhere that holding is necessary during surgery.
As explained above, in the present invention, when the magnet is brought close to the outside of a luminal organ, in which a magnetic body has been anchored on the inner surface thereof, the magnetic body is attracted to the magnet, and the wall of the luminal organ in which the magnetic body is anchored is deformed so as to lift up toward the outside. As a result, by observing this deformation from the outside of the luminal organ, it is possible to correctly estimate the site where the magnetic body is anchored easily and quickly.
Further, in the present invention, when the magnet is brought close to the outside of the luminal organ, in which a magnetic body has been anchored on the inner surface thereof, the magnetic body is attracted to the magnet, and the magnetic body is pulled and held to the magnet along with the wall of the luminal organ. It is possible to hold the body tissue which is difficult to grasp with the grasping forceps, etc., easily and correctly, without causing injury.
According to the present invention, it is possible to correctly estimate the position where the magnetic body is anchored easily and quickly, even from outside the luminal organ.
Further according to the present invention, it is possible to hold the body tissue which is difficult to grasp with the grasping forceps, etc., easily and correctly, without causing injury.
While preferred embodiments of the invention have been described and illustrated above, it should be understood that these are exemplary of the invention and are not to be considered as limiting. Additions, omissions, substitutions, and other modifications can be made without departing from the spirit or scope of the present invention. Accordingly, the invention is not to be considered as being limited by the foregoing description, and is only limited by the scope of the appended claims. | The present invention enables the desired area on a luminal organ to be held correctly during laparotomy or laparoscopic surgery, even without carrying out dot inking which requires a high degree of skill. In the present invention, a magnetic body is pre-anchored at a specific position inside a luminal organ. During surgery, a magnet is brought close to the outside of the luminal organ, such that the magnetic body is adsorbed to the magnet, along with the body tissue of the luminal organ, enabling traction. | 0 |
FIELD OF THE INVENTION
The present invention relates to polycarbonate moulding compositions which comprise aluminium compounds and have improved mechanical properties and an improved antistatic action.
BACKGROUND OF THE INVENTION
Thermoplastic moulding compositions, in particular those which comprise homo- and/or copolymers of one or more ethylenically unsaturated monomers, polycarbonates and polyesters, are known from a large number of publications. This particularly applies to the use of ABS polymers. Reference is made to the following documents merely by way of example: DE-A-19616, WO 97/40092, EP-A-728811, EP-A-315868 (=U.S. Pat. No. 4,937,285), EP-A 0174493 (U.S. Pat. No. 4,983,658), U.S. Pat. No. 5,030,675, JA 59202240, EP-A 0363608 (=U.S. Pat. No. 5,204,394), EP-A 0767204, EP-A 0611798, WO 96/27600 and EP-A 0754.
The thermoplastic moulding compositions described in this prior art are still in need of improvement in their mechanical properties. This particularly applies to the use of these moulding compositions in safety-relevant components, e.g. in the motor vehicle industry, where high requirements are imposed on elongation at break, ESC properties, notched impact strength, heat distortion point and processability.
The antistatic action of the known moulding compositions also still requires improvement.
DETAILED DESCRIPTION OF THE INVENTION
Surprisingly, it has now been found that polycarbonate moulding compositions have an antistatic action and improved mechanical properties if aluminium compounds are added to them.
The invention accordingly provides thermoplastic moulding compositions comprising thermoplastic polycarbonate and 0.01 to 30, preferably 0.01–20, particularly preferably 0.01–10 parts by wt. per 100 parts by wt. (polycarbonate) of aluminium compounds having an average particle diameter of 1 nm–20 μm, preferably 1 nm–10 μm, particularly preferably 5–500 nm and especially preferably 5–200 nm.
The invention in particular provides thermoplastic moulding compositions comprising
A. 40 to 99 parts by wt., preferably 50 to 95 parts by wt., particularly preferably 60 to 90 parts by wt. of an aromatic polycarbonate, B. 0 to 50, preferably 1 to 30 parts by wt. of a vinyl (co)polymer of at least one monomer chosen from the series consisting of styrene, α-methylstyrene, styrenes substituted on the nucleus, C 1 –C 8 -alkyl methacrylates and C 1 –C 8 -alkyl acrylates with at least one monomer from the series consisting of acrylonitrile, methacrylonitrile, C 1 –C 8 -alkyl methacrylates, C 1 –C 8 -alkyl acrylates, maleic anhydride and N-substituted maleimides, C. 0.5 to 60 parts by wt., preferably 1 to 40 parts by wt., particularly preferably 2 to 30 parts by wt. of a graft polymer comprising at least two monomers from the group consisting of mono- or polyunsaturated olefins, such as e.g. ethylene, propylene, chloroprene, butadiene and isoprene, vinyl acetate, styrene, α-methylstyrene, styrenes substituted on the nucleus, vinyl cyanides, such as e.g. acrylonitrile and methacrylonitrile, maleic anhydride and N-substituted maleimides, D. 0.01 to 30 parts by wt., preferably 0.01 to 20 parts by wt., particularly preferably 0.01 to 10 parts by wt. of aluminium compounds having an average particle diameter of 1 nm–20 μm, preferably 1 nm–10 μm, particularly preferably 5–500 nm and especially preferably 5–200 mm.
The sum of all the parts by weight of A+B+C+D gives 100.
Each of the components mentioned can also be used as mixture.
Component A
Thermoplastic aromatic polycarbonates according to component A which are suitable according to the invention are those based on diphenols of the formula (I)
wherein
A is a single bond, C 1 –C 5 -alkylene, C 2 –C 5 -alkylidene, C 5 –C 6 -cycloalkylidene, —S— or —SO 2 —, B is chlorine or bromine, q is 0, 1 or 2 and p is 1 or 0,
or alkyl-substituted dihydroxyphenylcycloalkanes of the formula (II)
wherein
R 7 and R 8 independently of one another each denote hydrogen, halogen, preferably chlorine or bromine, C 1 –C 8 -alkyl, C 5 –C 6 -cycloalkyl, C 6 –C 10 -aryl, preferably phenyl, and C 7 –C 12 -aralkyl, preferably phenyl-C 1 –C 4 -alkyl, in particular benzyl, m denotes an integer of 4, 5, 6 or 7, preferably 4 or 5, R 9 and R 10 can be chosen individually for each Z and independently of one another denote hydrogen or C 1 –C 6 -alkyl,
and
Z denotes carbon, with the proviso that on at least one atom Z R 9 and R 10 simultaneously denote alkyl.
Suitable diphenols of the formula (I) are e.g. hydroquinone, resorcinol, 4,4′-dihydroxydiphenyl, 2,2-bis-(4-hydroxyphenyl)-propane, 2,4-bis-(4-hydroxyphenyl)-2-methylbutane, 1,1-bis-(4-hydroxyphenyl)-cyclohexane, 2,2-bis-(3-chloro-4-hydroxyphenyl)-propane and 2,2-bis-(3,5-dibromo-4-hydroxyphenyl)-propane.
Preferred diphenols of the formula (I) are 2,2-bis-(4-hydroxyphenyl)-propane, 2,2-bis-(3,5-dichloro-4-hydroxyphenyl)-propane and 1,1-bis-(4-hydroxyphenyl)-cyclohexane.
Preferred diphenols of the formula (II) are 1,1-bis-(4-hydroxyphenyl)-3,3-dimethyl-cyclohexane, 1,1-bis-(4-hydroxyphenyl)-3,3,5-trimethylcyclohexane and 1,1-bis-(4-hydroxyphenyl)-2,4,4-trimethyl-cyclopentane.
Polycarbonates which are suitable according to the invention are both homopolycarbonates and copolycarbonates.
Component A can also be a mixture of the thermoplastic polycarbonates defined above.
Polycarbonates can be prepared in a known manner from diphenols with phosgene by the phase boundary process or with phosgene by the process in a homogeneous phase, the so-called pyridine process, it being possible for the molecular weight to be adjusted in a known manner by a corresponding amount of known chain stoppers.
Suitable chain stoppers are e.g. phenol, p-chlorophenol, p-tert-butylphenol or 2,4,6-tribromophenol, and also long-chain alkylphenols, such as 4-(1,3-tetramethylbutyl)-phenol, in accordance with DE-OS 2842005, or monoalkylphenols or dialkylphenols having a total of 8 to 20 C atoms in the alkyl substituents, in accordance with German Patent Application P 3506472.2, such as 3,5-di-tert-butylphenol, p-iso-octylphenol, p-tert-octylphenol, p-dodecylphenol and 2-(3,5-dimethyl-heptyl)-phenol and 4-(3,5-dimethyl-heptyl)-phenol.
The amount of chain stoppers is in general between 0.5 and 10 mol %, based on the sum of the particular diphenols of the formulae (I) and/or (II) employed.
Polycarbonates A which are suitable according to the invention have average molecular weights ( M w weight-average, measured e.g. by ultracentrifugation or scattered light measurement) of 10,000 to 200,000, preferably 20,000 to 80,000.
Polycarbonates A which are suitable according to the invention can be branched in a known manner, and in particular preferably by incorporation of 0.05 to 2 mol %, based on the sum of the diphenols employed, of compounds which are trifunctional or more than trifunctional, e.g. those having three or more than three phenolic groups.
Preferred polycarbonates are, in addition to bisphenol A homopolycarbonate, the copolycarbonates of bisphenol A with up to 15 mol %, based on the molar sum of diphenols, of 2,2-bis-(3,5-dibromo-4-hydroxyphenyl)-propane and the copolycarbonates of bisphenol A with up to 60 mol %, based on the molar sum of diphenols, of 1,1-bis-(4-hydroxyphenyl)-3,3,5-trimethylcyclohexane.
Polycarbonates A can be replaced in part or completely by aromatic polyester carbonates. The aromatic polycarbonates of component A can also contain polysiloxane blocks. The preparation thereof is described, for example, in DE-OS 3334872 and in U.S. Pat. No. 3,821,325.
Component B
Vinyl (co)polymers according to component B which can be employed according to the invention are those of at least one monomer from the series consisting of: styrene, α-methylstyrene and/or styrenes substituted on the nucleus, C 1 –C 8 -alkyl methacrylate and C 1 –C 8 -alkyl acrylate with at least one monomer from the series consisting of: acrylonitrile, methacrylonitrile, C 1 –C 8 -alkyl methacrylate, C 1 –C 8 -alkyl acrylate, maleic anhydride and/or N-substituted maleimides (B.2).
C 1 –C 8 -Alkyl acrylates and C 1 –C 8 -alkyl methacrylates are esters of acrylic acid and methacrylic acid respectively and monohydric alcohols having 1 to 8 C atoms. Methyl, ethyl and propyl methacrylate are particularly preferred. Methyl methacrylate is mentioned as a particularly preferred methacrylic acid ester.
Thermoplastic (co)polymers having a composition according to component B can be formed as a by-product during the grafting polymerization for the preparation of component C, especially if large amounts of monomers are grafted on to small amounts of rubber. The amount of (co)polymer B to be employed according to the invention does not include these by-products of the grafting polymerization.
(Co)polymers according to component B are resinous, thermoplastic and rubber-free.
Particularly preferred (co)polymers B are those of styrene (B1) with acrylonitrile and optionally with methyl methacrylate (B2), of α-methylstyrene (B1) with acrylonitrile and optionally with methyl methacrylate (B2), or of styrene (B1) and α-methylstyrene with acrylonitrile and optionally with methyl methacrylate (B2).
Thermoplastic (co)polymers B comprise 50 to 99, preferably 60 to 95 parts by wt. B.1 and 50 to 2, preferably 40 to 5 parts by wt. B.2.
The styrene/acrylonitrile copolymers according to component B are known and can be prepared by free-radical polymerization, in particular by emulsion, suspension, solution or bulk polymerization. The copolymers according to component B preferably have molecular weights M w (weight-average, determined by light scattering or sedimentation) of between 15,000 and 200,000.
Particularly preferred copolymers B according to the invention are also randomly built-up copolymers of styrene and maleic anhydride, which can be prepared from the corresponding monomers by a continuous bulk or solution polymerization with incomplete conversions.
The contents of the two components of the randomly built-up styrene/maleic anhydride copolymers which are suitable according to the invention can be varied within wide limits. The preferred content of maleic anhydride is 5 to 25 wt. %.
The molecular weights (number-average M n ) of the randomly built-up styrene/maleic anhydride copolymers according to component B which are suitable according to the invention can vary over a wide range. The range from 60,000 to 200,000 is preferred. A limiting viscosity of 0.3 to 0.9 (measured in dimethylformamide at 25° C.; in this context see Hoffmann, Krömer, Kuhn, Polymeranalytik I, Stuttgart 1977, page 316 et seq.) is preferred for these products.
Instead of styrene, vinyl (co)polymers B can also comprise styrenes which are substituted on the nucleus, such as p-methylstyrene, vinyltoluene and 2,4-dimethylstyrene, and other substituted styrenes, such as α-methylstyrene, which can optionally be halogenated.
Component C
Graft polymers C comprise e.g. graft copolymers with rubber-elastic properties which are substantially obtainable from at least two of the following monomers: chloroprene, 1,3-butadiene, isoprene, styrene, acrylonitrile, ethylene, propylene, vinyl acetate and (meth)-acrylic acid esters having 1 to 18 C atoms in the alcohol component; that is to say polymers such as are described e.g. in “Methoden der Organischen Chemie” (Houben-Weyl), vol. 14/1, Georg Thieme-Verlag, Stuttgart 1961, p. 393–406 and in C. B. Bucknall, “Toughened Plastics”, Appl. Science Publishers, London 1977. Preferred polymers C are partly crosslinked and have gel contents of more than 20 wt. %, preferably more than 40 wt. %, in particular more than 60 wt. %.
Preferred graft polymers C include graft polymers of:
C.1 5 to 95, preferably 30 to 80 parts by wt. of a mixture of C.1.1 50 to 95 parts by wt. styrene, α-methylstyrene, styrene substituted on the nucleus by halogen or methyl, C 1 –C 8 -alkyl methacrylate, in particular methyl methacrylate, or C 1 –C 8 -alkyl acrylate, in particular methyl methacrylate, or mixtures of these compounds and C.1.2 5 to 50 parts by wt. acrylonitrile, methacrylonitrile, C 1 –C 8 -alkyl methacrylate, in particular methyl methacrylate, C 1 –C 1 -alkyl acrylate, in particular methyl acrylate, maleic anhydride or C 1 –C 4 -alkyl- or phenyl-N-substituted maleimides, or mixtures of these compounds, on C.2 5 to 95, preferably 20 to 70 parts by wt. polymer having a glass transition temperature below −10° C.
Preferred graft polymers C are e.g. polybutadienes, butadiene/styrene copolymers and acrylate rubbers grafted with styrene and/or acrylonitrile and/or (meth)acrylic acid alkyl esters; i.e. copolymers of the type described in DE-OS 1694173 (=U.S. Pat. No. 3,564,077); and polybutadienes, butadiene/styrene or butadiene/acrylonitrile copolymers, polyisobutenes or polyisoprenes grafted with acrylic or methacrylic acid alkyl esters, vinyl acetate, acrylonitrile, styrene and/or alkylstyrenes, such as are described e.g. in DE-OS 2348377 (=U.S. Pat. No. 3,919,353).
Particularly preferred polymers C are e.g. ABS polymers, such as are described e.g. in DE-OS 2035390 (=U.S. Pat. No. 3,644,574) or in DE-OS 2248242 (=GB B 1409275).
Particularly preferred graft polymers C are graft polymers which are obtainable by a grafting reaction of
I. 10 to 70, preferably 15 to 50, in particular 20 to 40 wt. %, based on the graft product, of at least one (meth)acrylic acid ester or 10 to 70, preferably 15 to 50, in particular 20 to 40 wt. % of a mixture of 10 to 50, preferably 20 to 35 wt. %, based on the mixture, of acrylonitrile or (meth)acrylic acid ester and 50 to 90, preferably 65 to 80 wt. %, based on the mixture, of styrene on II. 30 to 90, preferably 50 to 85, in particular 60 to 80 wt. %, based on the graft product, of a butadiene polymer with at least 50 wt. %, based on II, of butadiene radicals as the graft base,
wherein the gel content of graft base 11 is preferably at least 20 wt. %, particularly preferably at least 40 wt. % (measured in toluene), the degree of grafting G is 0.15 to 0.55 and the average particle diameter d 50 of the graft polymer is 0.05 to 2 μm, preferably 0.1 to 0.6 μm.
(Meth)acrylic acid esters I are esters of acrylic acid or methacrylic acid and monohydric alcohols having 1 to 18 C atoms. Methyl, ethyl and propyl methacrylate are particularly preferred.
In addition to butadiene radicals, graft base II can contain up to 50 wt. %, based on II, of radicals of other ethylenically unsaturated monomers, such as styrene, acrylonitrile, esters of acrylic or methacrylic acid having 1 to 4 C atoms in the alcohol component (such as methyl acrylate, ethyl acrylate, methyl methacrylate and ethyl methacrylate), vinyl esters and/or vinyl ethers. The preferred graft base II comprises pure polybutadiene.
The degree of grafting G designates the weight ratio of grafted-on grafting monomer to graft base and has no dimensions.
The average particle size d 50 is the diameter above and below which in each case 50 wt. % of the particles lie. It can be determined by means of ultracentrifuge measurement (W. Scholtan, H. Lange, Kolloid, Z. und Z. Polymere 250 (1972), 782–796).
Particularly preferred polymers C are e.g. also graft polymers of
(a) 20 to 90 wt. %, based on C, of acrylate rubber having a glass transition temperature below −20° C. as the graft base and (b) 10 to 80 wt. %, based on C, of at least one polymerizable, ethylenically unsaturated monomer (cf. C.1) as the grafting monomer.
The acrylate rubbers (a) of polymers C are preferably polymers of acrylic acid alkyl esters, optionally with up to 40 wt. %, based on (a), of other polymerizable, ethylenically unsaturated monomers. Preferred polymerizable acrylic acid esters include C 1 –C 8 -alkyl esters, for example the methyl, ethyl, butyl, n-octyl and 2-ethylhexyl esters; halogenoalkyl esters, preferably halogeno-C 1 –C 8 -alkyl esters, such as chloro ethyl acrylate, and mixtures of these monomers.
For crosslinking, monomers having more than one polymerizable double bond can be copolymerized. Preferred examples of crosslinking monomers are esters of unsaturated mono carboxylic acids having 3 to 8 C atoms and unsaturated monohydric alcohols having 3 to 12 C atoms or saturated polyols having 2 to 4 OH groups and 2 to 20 C atoms, such as e.g. ethylene glycol dimethacrylate and allyl methacrylate; polyunsaturated heterocyclic compounds, such as e.g. trivinyl and triallyl cyanurate; polyfunctional vinyl compounds, such as di- and trivinylbenzenes; and also triallyl phosphate and diallyl phthalate.
Preferred crosslinking monomers are allyl methacrylate, ethylene glycol dimethacrylate, diallyl phthalate and heterocyclic compounds which contain at least 3 ethylenically unsaturated groups.
Particularly preferred crosslinking monomers are the cyclic monomers triallyl cyanurate, triallyl isocyanurate, trivinyl cyanurate, triacryloylhexahydro-s-triazine and triallylbenzenes.
The amount of crosslinking monomers is preferably 0.02 to 5, in particular 0.05 to 2 wt. %, based on graft base (a).
With cyclic crosslinking monomers having at least 3 ethylenically unsaturated groups, it is advantageous to limit the amount to less than 1 wt. % of graft base (a).
Preferred “other” polymerizable, ethylenically unsaturated monomers which can optionally be used, in addition to the acrylic acid esters, for the preparation of graft base (a) are e.g. acrylonitrile, styrene, α-methylstyrene, acrylamides, vinyl C 1 –C 6 -alkyl ethers, methyl methacrylate and butadiene. Preferred acrylate rubbers as graft base (a) are emulsion polymers which have a gel content of at least 60 wt. %.
Further suitable graft bases are silicone rubbers with grafting-active positions such as are described in the Offenlegungsschriften DE-OS 3704657, DE-OS 3704655, DE-OS 3631540 and DE-OS 3631539.
The gel content of graft base (a) is determined at 25° C. in dimethylformamide (M. Hoffmann, H. Krömer, R. Kuhn, Polymeranalytik I und II, Georg Thieme-Verlag, Stuttgart 1977).
Since as is known the grafting monomers are not necessarily grafted completely on to the graft base during the grafting reaction, according to the invention graft polymers C are also to be understood as those products which are obtained by polymerization of the grafting monomers in the presence of the graft base.
Component D
Compounds of aluminium with one or more metals of main groups 1 to 5 and sub-groups 1 to 8 of the periodic table, preferably main groups 2 to 5 and sub-groups 4 to 8, particularly preferably main groups 3 to 5 and sub-groups 4 to 8, or compounds with the elements oxygen, carbon, nitrogen, hydrogen, sulfur and silicon are suitable as component D.
Oxides, water-containing oxides, phosphates, sulfates, sulfides, hydroxides, borates and borophosphates of aluminium can be employed according to the invention. Aluminium oxide hydroxide, aluminium phosphate and aluminium borate are particularly preferred. Aluminium oxide hydroxide is especially preferred.
According to the invention, the particle size is <10 μm, preferably ≧5 μm.
Water-containing compounds such as aluminium oxide hydroxide are preferred.
Particle size and particle diameter always means the average particle diameter d 50 , determined by ultracentrifuge measurements by the method of W. Scholtan et al. Kolloid-Z. und Z. Polymere 250(1972), p. 782 to 796.
The aluminium compounds can be in the form of powders, pastes, sols, dispersions or suspensions. Powders can be obtained by precipitation from dispersions, sols or suspensions.
The powders can be incorporated into the thermoplastics by conventional processes, for example by direct kneading or extrusion of the constituents of the moulding composition and the very fine-particled inorganic powders. Preferred processes are the preparation of a masterbatch, e.g. in flameproofing additives, other additives, monomers, solvents or in component A, or coprecipitation of dispersions of components B or C with dispersions, suspensions, pastes or sols of the very fine-particled inorganic materials.
The moulding compositions according to the invention can comprise conventional additives, such as very fine-particled inorganic compounds, lubricants and mould release agents, nucleating agents, antistatics, stabilizers, fillers and reinforcing materials and dyestuffs and pigments. The processing auxiliaries are added in the conventional amounts.
The inorganic compounds include compounds of one or more metals of main groups 1 to 5 or sub-groups 1 to 8 of the periodic table, preferably main groups 2 to 5 or sub-groups 4 to 8, particularly preferably main groups 3 to 5 or sub-groups 4 to 8, with the elements oxygen, sulfur, boron, phosphorus, carbon, nitrogen, hydrogen and/or silicon.
Preferred compounds are, for example, oxides, hydroxides, water-containing oxides, sulfates, sulfites, sulfides, carbonates, carbides, nitrates, nitrites, nitrides, borates, silicates, phosphates, hydrides, phosphites or phosphonates.
Preferred very fine-particled inorganic compounds are, for example, TiN, TiO 2 , SnO 2 , WC, ZnO, ZrO 2 , Sb 2 O 3 , SiO 2 , iron oxides, NaSO 4 , BaSO 4 , vanadium oxides, zinc borate and silicates, such as Al silicates, Mg silicates and one-, two- and three-dimensional silicates. Mixtures and doped compounds can also be used. Furthermore, these nanoscale particles can also be surface-modified with organic molecules in order to achieve a better compatibility with the polymers. Hydrophobic or hydrophilic surfaces can be generated in this manner.
The average particle diameters are less than 200 nm, preferably less than 150 nm, in particular 1 to 100 nm.
Particle size and particle diameter always means the average particle diameter d 50 , determined by ultracentrifuge measurements by the method of W. Scholtan et al. Kolloid-Z. und Z. Polymere 250 (1972), p. 782 to 796.
The inorganic compounds can be in the form of powders, pastes, sols, dispersions or suspensions. Powders can be obtained by precipitation from dispersions, sols or suspensions.
The moulding compositions can comprise up to 25 parts by wt. (based on the total moulding composition) of inorganic compounds.
The powders can be incorporated into the thermoplastics by conventional processes, for example by direct kneading or extrusion of the constituents of the moulding composition and the very fine-particled inorganic powders. Preferred processes are the preparation of a masterbatch, e.g. in flameproofing additives, other additives, monomers, solvents or in component A, or coprecipitation of dispersions of components B or C with dispersions, suspensions, pastes or sols of the very fine-particled inorganic materials.
The thermoplastic moulding compositions can comprise inorganic fillers and reinforcing materials, such as glass fibres, optionally cut or ground, glass beads, glass balls, reinforcing material in platelet form, such as kaolin, talc, mica, silicates, quartz, talc, titanium dioxide, wollastonite, mica, carbon fibres or mixtures thereof. Cut or ground glass fibres are preferably employed as the reinforcing material.
Preferred fillers, which can also have a reinforcing action, are glass beads, mica, silicates, quartz, talc, titanium dioxide and wollastonite.
The moulding compositions with a filler or reinforcing material content can comprise up to 60, preferably 10 to 40 wt. %, based on the moulding composition with a filler or reinforcing material content, of fillers and/or reinforcing substances.
The moulding compositions according to the invention are prepared by mixing the particular constituents in a known manner and subjecting the mixture to melt compounding or melt extrusion at temperatures of 200° C. to 300° C. in conventional units, such as internal kneaders, extruders and twin-screw extruders, the fluorinated polyolefins preferably being employed in the form of the coagulated mixture already mentioned.
The individual constituents can be mixed in a known manner both successively and simultaneously, and in particular both at about 20° C. (room temperature) and at a higher temperature.
The moulding compositions of the present invention can be used for the production of all types of shaped articles. In particular, shaped articles can be produced by injection moulding. Examples of shaped articles which can be produced are: housing components of all types, e.g. for domestic appliances, such as juice presses, coffee machines and mixers, or for office machines, such as computers, printers and monitors, or covering sheets for the building sector and components for the motor vehicle sector. They are moreover employed in the field of electrical engineering, because they have very good electrical properties.
The moulding compositions are particularly suitable for the production of thin-walled mouldings (e.g. data technology housing components), where particularly high requirements are imposed on the notched impact strength and stress-cracking resistance of the plastics employed.
Another form of processing is the production of shaped articles by blow moulding or by thermoforming from previously produced sheets or films.
EXAMPLES
Component A
Polycarbonate based on bisphenol A with a relative solution viscosity of 1.252, measured in methylene chloride at 25° C. and in a concentration of 0.5 g/100 ml.
Component B
Styrene/acrylonitrile copolymer with a styrene/acrylonitrile ratio of 72:28 and a limiting viscosity of 0.55 dl/g (measurement in dimethylformamide at 20° C.).
Component C
Graft polymer of 40 parts by wt. styrene and acrylonitrile in a ratio of 73:27 on 60 parts by wt. crosslinked polybutadiene rubber in particle form (average particle diameter d 50 =0.3 μm), prepared by emulsion polymerization.
Component D
Pural 200, an aluminium oxide hydroxide (Condea, Hamburg, Germany) is employed as the inorganic compound. The average particle size of the material is approx. 20–40 nm.
Preparation and Testing of the Moulding Compositions According to the Invention
Components A to D are mixed on a 3 1 internal kneader. The shaped articles are produced on an injection moulding machine type Arburg 270E at 260° C.
The tensile E modulus is measured in accordance with the method of ISO 527.
The elongation at break DR is determined in the context of the determination of the tensile E modulus in accordance with the method of ISO 527 on F3 dumbbell bars.
The antistatic action is determined by a dust figure test. For this circular sheets are charged statically with a cotton cloth and then dusted with aluminium powder. The evaluation is visual.
The Vicat B heat distortion point is determined in accordance with DIN 53460.
The composition of the materials tested and the data obtained are summarized in the following table 1.
TABLE 1
1
Examples
Comparison
2
Components: [%]
A
42.60
42.18
B
32.70
32.38
C
23.80
23.57
D
−
0.99
Additives
0.90
0.88
(processing auxiliaries)
Properties:
Vicat B 120 [° C.]
111
111
Dust figure test
−
+
Tensile E modulus [N/mm 2 ]
1,982
2,143
Elongation at break [%]
44.6
62.5
MUR (260° C./5 kg)
8.3
12.2
[ccm/10 min]
a k Izod 260° C./23° C.
61.9
66.6
[kJ/m 2 ]
The foregoing examples of the present invention are offered for the purpose of illustration and not limitation. It will be apparent to those skilled in the art that the embodiments described herein may be modified or revised in various ways without departing from the spirit and scope of the invention. The scope of the invention is to be measured by the appended claims. | A thermoplastic molding compositions comprising thermoplastic polycarbonate and an additive amount of an aluminum compound is disclosed. The aluminum compound is characterized by its particle size and the composition is characterized by its improved anti-static properties. | 2 |
BACKGROUND OF THE INVENTION
The present invention relates to devices for reconditioning the cutting edges of cutting implements and, more particularly, devices for scoring corrugations along the beveled cutting edges of scissors' blades.
In sharpening the blades of hair cutting scissors, it is necessary to rescore corrugations along the cutting edges. The corrugations hold the hair and prevent the hair strands from sliding along the scissors' blades as the blades close to shear the hair, thereby making possible greater precision in performing a hair cutting operation. Repeated sharpening of the beveled cutting edges of corrugated scissors' blades wears away the corrugations, making it necessary to recorrugate the blades after sharpening.
Typically, corrugations are scored into the cutting edges of scissors' blades with a corrugating file in a process done by hand, with the result that the precision of the formation of corrugations is highly dependent upon the skill of the craftsman performing the filing operation in holding the file at the proper angle to the beveled edge and exerting a consistently sufficient downward force into the blade to form corrugations of the appropriate depth. Furthermore, as a result of this human element, the pressure and resultant depth of the scoring, the spacing of scoring, and other parameters will vary along a beveled edge of a scissors' blade as well as from one craftsman to the next. Accordingly, there is a need to provide a device which scores corrugations along the beveled cutting edges of scissors' blades with repeatable precision and with a predetermined filing force which results in an even depth of scoring along the cutting edge.
Attempts have been made to develop a device for forming serrations on scissors' blades, and an example of such a device is shown in Mikesell U.S. Pat. No. 966,036. That patent shows a serrating device in which a serrating file is held horizontally by a pivotal attachment at one end to a support rod and a pivotal attachment to a link arm at an opposite end. The link arm is pivotally attached to the support rod at a location spaced from the pivotal connection with the file. A clamp is used to hold the scissors' blade such that the beveled edge of the blade is substantially horizontal and parallel to the flat working underside of the file.
The sharpening process is conducted by oscillating the file in an arc having as its center the pivotal connection between the file end and the rod. Although this device provides a measure of uniformity in scoring serrations on a scissors' blade, there is no control over the downward force exerted by the user operating the file upon the beveled edge of the blade. As a result, the depth of the serrations may vary along the length of a cutting edge as well as from user to user.
In performing a corrugating operation upon a scissors' blade, it is desirable to move the file relative to the beveled edge in a direction which is perpendicular to the beveled cutting edge. If the file is moved in a direction skewed to the cutting edge, the scoring is less effective. Since the movement of the corrugating file in the aforementioned Mikesell patent is pivotal rather than linear, the direction of the file movement during a corrugating operation can only approximate a linear stroke.
There are analogous structures found in the scissors sharpening art. Exemplary of such devices are the sharpeners disclosed in Petrich U.S. Pat. No. 1,904,075; Foster U.S. Pat. No. 2,397,256; Garbarino U.S. Pat No. 2,557,093; and Eaton U.S. Pat. No. 1,681,763. In each of these devices, a scissors' blade is held in a clamp, vise or the like, and a file is drawn across the beveled cutting edge at an angle parallel to the beveled edge. The file is supported at one end by the sharpening device and is grasped by the user at the opposite end, so that the user must attempt to apply a consistent and sufficient downward pressure to effect the requisite frictional engagement between the working face of the file and the cutting edge of the scissors' blade. Again, the pressure exerted by the file upon the instrument to be sharpened in each of these devices will vary along the length of the scissors' blade as well as from user to user.
Accordingly, there is a need for a corrugating device which is capable of scoring corrugations in the beveled cutting edge of a scissors' blade in an accurate and repeatable manner. Furthermore, it is desirable to provide such a device with means for regulating the downward pressure of the file against the cutting edge, so that it remains within predictable limits, regardless of the skill of the user.
SUMMARY OF THE INVENTION
The present invention is a scissors corrugating device in which a corrugating file is held by upper and lower guides such that the file is oriented parallel to the beveled edge of a scissors' blade clamped in position beneath it. The guides limit the movement of the file to a path in which the file is moved perpendicularly across the cutting edge as well as downwardly into the cutting edge a predetermined distance and depth. The device produces a mechanical advantage allowing adequate force throughout the stroke. These benefits are constant with each stroke, regardless of the skill or proficiency of the operator. The result is that the corrugating device of the present invention can score corrugations in the beveled edge of a scissors' blade with a high degree of accuracy and repeatability.
In a preferred embodiment of the invention, the corrugating device includes a frame having front and rear pairs of opposing side walls. Upper and lower pairs of guide tracks are formed in the side walls and receive the ends of upper and lower guide shafts, respectively, which extend between the side walls. Upper and lower clamps are slidably mounted on the upper and lower guide shafts, respectively, and are adapted to receive the ends of a corrugating file.
A vise is attached to the frame and includes a pair of clamping jaws which are adapted to hold the scissors' blade to be corrugated. The vise is adjustable so that the scissors' blade's orientation can be adjusted relative to the fixed motion of the corrugating file.
The lower guide slots are oriented to form a path which is substantially parallel to the beveled cutting edge of the clamped scissors' blade. The upper guide slots are oriented to form a path which makes an angle with the path of the lower guide slots and with the beveled cutting edge. Therefore, when the file is pushed across the clamped scissors' blade, the sliding engagement of the guide rods with the guide slots causes the file to move perpendicularly across and slightly down into the beveled cutting edge of the scissors' blade, thereby scoring corrugations of a predetermined depth. A mechanical advantage is realized as a result of a lever arm applied at the fulcrum of the scissors' blade's reaction with the file and the reaction on the upper and lower slot contact points. This process is repeated along the length of the scissors' blade by successively sliding the clamps across the guide rods slightly after each filing stroke or series of strokes, from one side of the frame to the other.
Also in the preferred embodiment, the jaws of the vise include a support pin and a support wedge, both slidable between the jaws of the vise, for supporting the side of the scissors' blade opposite the beveled cutting edge. This is desirable since the clamping force necessary to hold the blade in place during a corrugating operation is reduced when the scissors' blade is supported in this manner. The use of the wedge provides a measure of continuous adjustability to this support so that scissors' blades having a variety of configurations can be supported and so that the cutting edge can be aligned parallel to the plane of the file.
Accordingly, it is an object of the present invention to provide a scissors corrugating device in which an operator can move a corrugating file over the beveled cutting edge of a scissors' blade to score corrugations thereon in a manner which forms even and consistent corrugations which are perpendicular to the blade and which are of uniform depth along the length of the blade; a device in which such corrugations can be formed uniformly at an optimal depth regardless of the skill or coordination of the user; a corrugating device in which scissors' blades having a variety of shapes can be corrugated; and a device which scores corrugations on beveled cutting edges with a mechanical advantage on the part of the user.
Other objects and advantages will be apparent from the following description, the accompanying drawings and the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an exploded perspective view showing a preferred embodiment of the scissors corrugating device of the present invention, in which a rear side wall is partially broken away;
FIG. 2 is a side elevation in section of the device, taken at line 2--2 of FIG. 1, and showing the file and file support guides at the end of a corrugating stroke in phantom;
FIG. 3 is a front end elevation of the device shown in FIG. 2, in which the front side walls are broken away to show the guide slots, and the struts are broken to show the file and file support guides;
FIG. 4 is a detail showing the jaws of the blade vise shown in FIGS. 1-3 in which the support pin and support wedge are exploded away from their respective bores and notches;
FIG. 5 is a detail of the vise of FIGS. 1-3 showing the adjustable attachment to the frame;
FIG. 6 is a detail of the vise of FIGS. 1-3 showing a scissors' blade resting upon the support pin and wedge, both in section, adjacent a jaw;
FIG. 7 is a schematic view of the scissors' blade, corrugating file and support guides, showing the paths followed by the guides and the angular relationships between the guide paths and beveled cutting edge; and
FIG. 8 is a schematic view as in FIG. 7, except that the corrugating file has been displaced along the paths of the support guides.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
As best shown in FIGS. 1 and 2, the scissors corrugating device comprises a frame, generally designated 10, a vise 12 mounted on the frame, and upper and lower guides, generally designated 14, 16, respectively. A corrugating file 18 of a type well-known in the art extends between the upper and lower guides 14, 16, respectively. A preferred type of file 18 is a Nicholson brand 6" righthand corrugating file.
The frame 10 includes a base plate 20, a pair of opposing front side walls 22, 24, respectively, and a pair of opposing rear side walls 26, 28, respectively. The front side walls 22, 24 are attached at lower ends thereof to the sides of the base plate 20 by cap screws 30. The upper ends of the front side walls 22, 24 are secured to each other by transverse struts 32, 34, which are attached to the side walls by cap screws 36. Similarly, the rear side walls 26, 28 are attached to sides of the base plate 20 by cap screws 38 (shown in FIGS. 1 and 2 only for side wall 28), and are secured to each other at their upper ends by transverse struts 40, 42 attached by cap screws 44.
As shown in FIGS. 1, 2 and 3, front side walls 22, 24 include a pair of opposing lower slots 46, 48, respectively; and rear side walls 26, 28 include a pair of opposing upper slots 50, 52, respectively. The lower guide 16 includes a lower guide shaft 54 extending transversely of the base plate 20 and having roller bearings 56, 58 at its ends which are positioned within the lower slots 46, 48, respectively. A lower clamp 60 includes a block 62 which is slidably journaled on the lower guide shaft 54 and receives a lower end of the file 18 in a groove 64. A plate 66 is attached to the block by cap screws 68 to secure the file 18 within the groove 64.
Similarly, the upper guide 14 includes an upper guide shaft 70 extending transversely of the base plate 20 and having roller bearings 72, 74 at its ends positioned within the upper slots 50, 52, respectively. An upper clamp 76, similar to lower clamp 60, includes a block 78 slidably journaled on the upper guide shaft 70 and receives an upper end of the file 18 within a groove (not shown), and includes a plate 80, attached to the block by cap screws 81 to secure the file end within the groove. Two return springs 82 are secured to the rear side walls 26, 28 at their ends by screws 83, and their opposite ends are attached to the ends of shaft 70.
As shown in FIGS. 1, 2 and 4, the vise 12 resembles vises of well-known design and includes opposing jaws 84, 86 and a screw 88 which reciprocates jaw 86 relative to jaw 84. Screw 88 is threaded through the jaw 84 and includes a handle 90. Jaws 84, 86 include a pattern of pairs of opposing bores 92, 94 and, spaced from the bores, a pair of opposing notches 96, 98, respectively. A blade support pin 100 is positioned within the bores 92, 94. A support wedge 102 is positioned within notches 96, 98 and is shaped such that it may be slidably positioned relative to the jaws 84, 86. Support wedge 102 includes opposing longitudinal edges 104, 106 which are oriented to form an acute angle A with each other.
The support pin 100 and support wedge 102 are located relative to the jaws to vertically support and to prevent slippage of the scissors' blade 108 between the opposing jaws 84, 86 (see FIG. 6). The modification of the vise 12 to include the pin 100 and wedge 102 provides two distinct advantages over prior art corrugating devices having conventional vises. First, by vertically supporting the scissors' blade 108 on its side 110 opposite the beveled cutting edge 112, less clamping force is required to secure the scissors' blade in a fixed position during the corrugating operation, so that less stress and effort need be applied by an operator on the handle 90 and screw 88 (FIG. 2).
Second, the use of the support wedge 102 provides a measure of continuous adjustability so that any number of scissors' blades 108 having varying contours may be supported in vise jaws 84, 86 and be firmly held in a position so that side 112 of blade 108 is held parallel to the plane of the file. To make the adjustment, the scissors' blade is placed upon the support pin 100 and the support wedge is slid transversely of the jaws 84, 86 within the notches 96, 98 until it contacts the side 110 of the blade and rotates the side 112 of blade 108 to a position parallel to plane of file. An analytical study of this design suggests that a preferred angle A is approximately 15.5°. A wedge 102 having this shape provides an optimum combination of a relatively wide vertical range of support and a minimum of slippage based on the coefficient of friction between the notches 96, 98 of the vise 12 and the wedge.
In order to perform the corrugating operation at a 19° angle, it is necessary that a scissors' blade 108 clamped between jaws 84, 86 be oriented substantially perpendicularly to the base plate 20, which would be a substantially vertical orientation if the base plate rested upon a substantially horizontal supporting surface (not shown). However, to allow some variation in corrugation angles, the vise includes a measure of adjustability. Since the position and movement of the file is fixed, the vise incorporates adjustability through its base to change the angle of the scissors' blade and the vertical positioning of the scissors' relative to the file motion. In order to provide the greatest flexibility in the positioning of the scissors' side 112 relative to the file motion, the vise 12 includes an adjustable base 114 which is secured to the base plate 20 by cap screws 116 which are threaded into the base plate. Cap screws 116 are not threaded into the base 114 but rather are inserted through loosely toleranced holes (not shown) formed in the base.
Adjusting cap screws 118 are threaded through the base 114 and contact the upper surface of the base plate 20. By varying the depth of the cap screws 118 relative to the base 114, the elevation and vertical orientation of the jaws 84, 86 of the vise 12 can be adjusted. As shown in FIGS. 2 and 6, it is preferable that the vise 12 be positioned such that the beveled cutting edge 112 of the scissors+ blade 108 contacts the working underside face of the file 18 when the guides 14, 16 are in their uppermost positions within the slots 46, 48, 50, 52, respectively.
In order for the upper and lower guides 14, 16, respectively, (FIG. 1) to constrain movement of the file 18 to a path of movement which brings it perpendicularly across the beveled cutting edge 112 of the scissors+ blade 108 and downwardly into the blade, it is necessary that the angular orientation of the lower guide slots 46, 48 differ from that of the upper guide slots 50, 52. This relationship is best shown in FIGS. 7 and 8. The lower slots 46, 48 define a path indicated by line 120 which makes an angle of approximately 19° with the horizontal, represented by line 122. This angle is chosen because the beveled cutting edge 112 of most scissors' blades, represented by scissors' blade 108, typically is angled at approximately 19° from the horizontal when the blade is oriented substantially vertically as shown in the figures.
The upper guide 14 is constrained by the angular orientation of slots 50, 52 (FIG. 1) to move in a path represented by line 124 which forms an angle with the horizontal line 122 of approximately 23°, which is slightly steeper than the path defined by line 120. Therefore, as the file 18 is moved relative to the scissors' blade 108, the file is moved across the beveled cutting edge 112 and downwardly into the cutting edge to score the corrugations upon it.
At the start of the corrugating stroke, shown in FIG. 7, the guides 14, 16 and file 18 are in an upper position in which the underside 124 of the file is just touching the cutting edge 112 of the blade 108, the point of contact represented by point B. The relative positions of the upper and lower guides 14, 16, respectively, are represented by the points C, D, respectively.
At the end of the corrugating stroke, the upper and lower guides 14, 16, respectively, have moved along paths 124, 120, respectively, to locations designated in the figures as C', D', respectively. As a result of the different angular orientations of the paths 124, 120, the file 18 is urged downwardly into the beveled cutting edge 112 from point of contact B to point B' on the blade 108 (shown greatly exaggerated in FIG. 8). Therefore, for each stroke of the corrugating file 18, the working surface 124 is moved across the cutting edge 112 and downwardly into a predetermined distance and with a predetermined amount of pressure which is substantially constant for each stroke, regardless of the skill and proficiency of the user, and regardless of the contour of the scissors' blade. Springs 82 will return file to the uppermost position.
It should be noted, however, that in the preferred embodiment the path 120 followed by the lower guide 16 is to be parallel to the angular orientation of the beveled cutting edge 112 of the scissors' blade 108. Accordingly, it may be necessary at times to orient the vise 12 (FIG. 1) to hold the scissors' blade at an angle not substantially vertical in order to place the beveled cutting edge in such a parallel relationship with the path 120.
To operate the device 10, the scissors' blade 108 is first positioned between the jaws 84, 86 of the vise 12 and clamped into place so that it is substantially perpendicular to vise 12. The scissors' blade 108 should be positioned to rest upon the support pin 100 and support wedge 102 prior to clamping in the manner previously described. If necessary, the vise is then adjusted relative to the base plate 20 to position the beveled cutting edge 112 at an angle of 19° from the horizontal (again, assuming that the support plate 20 is resting upon a horizontal surface). Additionally, the beveled cutting edge 112 should be oriented parallel to the plane of the file and relative to the file such that it just touches the working underside 124 of the file when the upper and lower guides 14, 16, respectively, are in their uppermost position as shown in FIG. 1. The device 10 is now ready to perform a corrugating operation upon the scissors' blade 108.
To perform the operation, the operator simply urges the file in a generally downward direction by pushing the upper clamp 76 so that the bearings 72, 74, 56, 58 slide within their respective slots 50, 52, 46, 48. This movement guides the file 18 downwardly across the beveled cutting edge 112 of the blade 108 and downwardly into the blade, thereby scoring corrugations in the cutting edge. This process can be repeated along the length of the beveled cutting edge 112 by sliding the clamps 76, 60 from one end of the support shafts 70, 54 to the other. If the blade 108 is longer than the distance between the side walls 22, 24, 26, 28, as shown in FIG. 1, it is necessary for the jaws 84, 86 to be separated and the scissors' blade 108 to be repositioned relative thereto.
The corrugating device 10 preferably is made of a medium strength steel which possesses sufficient strength and wear characteristics to withstand the stresses involved. It may also be desirable to provide a corrosion-resistant coating on the components to inhibit the formation of rust or other deposits. A force analysis of the design of the preferred embodiment indicates a mechanical advantage such that an input force of two pounds produces a maximum downward reaction force of 119 pounds (529.3N). Also in the preferred embodiment, the motion downwardly into the cutting edge is preferably 0.0625 inches (0.1588 cm ), with a stroke of approximately 2 inches (5.08 cm). The angle of the file will not be changed by more than 2° between the beginning and end of the stroke.
While the form of apparatus herein described constitutes a preferred embodiment of this invention, it is to be understood that the invention is not limited to this precise form of apparatus, and that changes may be made therein without departing from the scope of the invention. | A scissors corrugating device comprising an elongate corrugating file, an upper guide attached to the file at an upper end, a lower guide attached to the file at a lower end, a frame for supporting the guides, and a vise attached to the frame and including clamping jaws tooled to firmly hold a scissors' blade vertically and at various angles beneath the file. The lower guide moves linearly in slots formed in the frame in a path which is substantially parallel to the beveled edge of the clamped scissors' blade, and the upper guide moves within a second pair of slots formed in the frame along a path which is at an angle to the path of the lower guide. With each stroke of the file across the beveled edge of a clamped scissors' blade, the paths cause the guides and file to travel across the beveled edge and downwardly to score corrugations evenly, with repeatability along the beveled edge, and provide an improved mechanical advantage. | 1 |
BRIEF DESCRIPTION OF THE DRAWINGS
[0001] The apparatus is described with reference to the accompanying drawings. In the drawings, like reference numbers indicate identical or functionally similar elements.
[0002] FIG. 1 is a sectional schematic of the scent machine; and
[0003] FIG. 1A is a plan view of the fragrance-infused disc.
DETAILED DESCRIPTION
[0004] The various embodiments of the present invention and their advantages are best understood by referring to FIGS. 1 and 1A of the drawings. The elements of the drawings are not necessarily to scale, emphasis instead being placed upon clearly illustrating the principles of the invention. Throughout the drawings, like numerals are used for like and corresponding parts of the various drawings.
[0005] Furthermore, reference in the specification to “an embodiment,” “one embodiment,” “various embodiments,” or any variant thereof means that a particular feature or aspect of the invention described in conjunction with the particular embodiment is included in at least one embodiment of the present invention. Thus, the appearance of the phrases “in one embodiment,” “in another embodiment,” or variations thereof in various places throughout the specification are not necessarily all referring to its respective embodiment.
[0006] This invention may be provided in other specific forms and embodiments without departing from the essential characteristics as described herein. The embodiments described above are to be considered in all aspects as illustrative only and not restrictive in any manner.
[0007] A scent machine 10 comprises a housing 1 having a base 5 supporting a body 4 to which is coupled a top cone 3 . Body 4 and top cone 3 define an open interior chamber 12 . The base 5 is configured with a baffled opening 8 that allows the intake of ambient air into the housing 1 . Base 5 may further comprise a plurality of elongated risers 9 to elevate the machine 10 above the surface upon which it sets in order to allow air to flow freely to the opening 8 and into the chamber 12 . Risers 9 may be connected together.
[0008] The body houses a fan 6 , preferably powered by a battery 16 , which may be a rechargeable battery, and a filter 7 . Fan 6 may also be adapted to include a power supply configured to relay power from standard residential electrical systems as would be appreciated by those skilled in the arts. The top cone 3 comprises a generally circular base section extending upward from the body 4 with an opening 11 in the top. In general operation, the fan 6 is configured to draw ambient air into the housing 1 through the baffled 8 opening in the base 5 , through the filter 7 , and to impel such air through the top cone 3 and out the top opening 11 .
[0009] The top cone 3 is also configured with one or more slots 13 circumferentially defined in the wall of the cone 3 near the top opening 11 , and downstream of the fan 6 . The slot is dimensioned to receive a disc 14 comprising an annular ring with a central opening 15 and which is infused with a pleasant fragrance. Accordingly, air impelled by the fan 6 through the top cone 3 passes through the central opening 15 of the scented disc 14 that is inserted into the slot 13 and the fragrance emanating from the disc 14 becomes entraining the air stream which exits the top cone 3 through the top opening 11 .
[0010] As described above and shown in the associated drawings, the present invention comprises a scent machine with air filter. While particular embodiments have been described, it will be understood, however, that any invention appertaining to the apparatus described is not limited thereto, since modifications may be made by those skilled in the art, particularly in light of the foregoing teachings. It is, therefore, contemplated by the appended claims to cover any such modifications that incorporate those features or those improvements that embody the spirit and scope of the invention. | A scent machine includes a housing defining an interior chamber with a top cone in which is defined a top opening and a slot defined circumferentially in a wall of the top cone. The machine further includes a filter housed and a fan housed within the chamber. The slot receives a fragrance-infused disc. | 0 |
CROSS REFERENCE TO RELATED APPLICATIONS
This application is related to co-pending U.S. patent application Ser. No. 12/651,354 for CENTRALIZED FILE ACTION BASED ON ACTIVE FOLDERS and filed concurrently herewith, which is incorporated herein by reference for all purposes; and to co-pending U.S. patent application Ser. No. 12/651,360 for RESOURCE ALLOCATION BASED ON ACTIVE FOLDER ACTIVITY and filed concurrently herewith, which is incorporated herein by reference for all purposes.
FIELD OF THE INVENTION
The present invention relates generally to data systems, and more particularly, to systems and methods of efficiently processing information.
BACKGROUND OF THE INVENTION
Information technology has advanced tremendously in recent years. Storage capacity has increased exponentially, broadband internet access is more accessible than ever, digital cameras and camcorders are producing increasingly higher quality pictures and videos, and the smartphone is replacing the PC in many aspects. With such advances, users are now able to obtain a vast amount of data from almost anywhere, and retain that data.
Unfortunately, this vast amount of data puts a strain on many applications. Applications now need to sift through large storage devices and data systems in order to find relevant information—a process that is becoming more resource intensive and time consuming.
There is a need, therefore, for an improved method, article of manufacture, and apparatus for processing information.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will be readily understood by the following detailed description in conjunction with the accompanying drawings, wherein like reference numerals designate like structural elements, and in which:
FIG. 1 is a flowchart of a method in accordance with some embodiments.
FIG. 2 is a flowchart of a method to store information in accordance with some embodiments.
FIGS. 3A-3C are screen shots of a method to create an active folder in accordance with some embodiments.
FIG. 4 is a flowchart of a method to upload files in accordance with some embodiments.
FIG. 5 is a flowchart of a method to automate application activity in accordance with some embodiments.
FIG. 6 is a flowchart of a method to allocate system resources in accordance with some embodiments.
DETAILED DESCRIPTION
A detailed description of one or more embodiments of the invention is provided below along with accompanying figures that illustrate the principles of the invention. While the invention is described in conjunction with such embodiment(s), it should be understood that the invention is not limited to any one embodiment. On the contrary, the scope of the invention is limited only by the claims and the invention encompasses numerous alternatives, modifications, and equivalents. For the purpose of example, numerous specific details are set forth in the following description in order to provide a thorough understanding of the present invention. These details are provided for the purpose of example, and the present invention may be practiced according to the claims without some or all of these specific details. For the purpose of clarity, technical material that is known in the technical fields related to the invention has not been described in detail so that the present invention is not unnecessarily obscured.
It should be appreciated that the present invention can be implemented in numerous ways, including as a process, an apparatus, a system, a device, a method, or a computer readable medium such as a computer readable storage medium containing computer readable instructions or computer program code, or as a computer program product, comprising a computer usable medium having a computer readable program code embodied therein. In the context of this disclosure, a computer usable medium or computer readable medium may be any medium that can contain or store the program for use by or in connection with the instruction execution system, apparatus or device. For example, the computer readable storage medium or computer usable medium may be, but is not limited to, a random access memory (RAM), read-only memory (ROM), or a persistent store, such as a mass storage device, hard drives, CDROM, DVDROM, tape, erasable programmable read-only memory (EPROM or flash memory), or any magnetic, electromagnetic, infrared, optical, or electrical means system, apparatus or device for storing information. Alternatively or additionally, the computer readable storage medium or computer usable medium may be any combination of these devices or even paper or another suitable medium upon which the program code is printed, as the program code can be electronically captured, via, for instance, optical scanning of the paper or other medium, then compiled, interpreted, or otherwise processed in a suitable manner, if necessary, and then stored in a computer memory. Applications, software programs or computer readable instructions may be referred to as components or modules. Applications may be hardwired or hard coded in hardware or take the form of software executing on a general purpose computer or be hardwired or hard coded in hardware such that when the software is loaded into and/or executed by the computer, the computer becomes an apparatus for practicing the invention. Applications may also be downloaded in whole or in part through the use of a software development kit or toolkit that enables the creation and implementation of the present invention. In this specification, these implementations, or any other form that the invention may take, may be referred to as techniques. In general, the order of the steps of disclosed processes may be altered within the scope of the invention.
An embodiment of the invention will be described with reference to a data system configured to store files, but it should be understood that the principles of the invention are not limited to data systems. Rather, they are applicable to any system capable of storing and handling various types of objects, in analog, digital, or other form. Although terms such as document, file, object, etc. may be used by way of example, the principles of the invention are not limited to any particular form of representing and storing data or other information; rather, they are equally applicable to any object capable of representing information.
Today, conventional implementations of storage systems is to provide mechanisms where individual applications request data from the storage system indicating when files or data objects are acted upon. For example, if a word processing application wanted to know when a specific word processing document was last modified, the word processing application would have to request that data from the storage system. This conventional approach leaves no centralized location for applications to monitor file actions, and requires applications to monitor the storage system for such file events. The enhanced techniques described herein improve the storage system by implementing a central location for watching files and execution of actions based on predefined or user configured policies.
To improve the storage system, active folders may be used. Active folders are folders with attributes that are associated with the storage, modification, or deletion of files in the folder. An active system, which executes actions based on the file events in the active folder, may also be used.
FIG. 1 illustrates an embodiment of the present invention. User 100 places a file in Active Folder 102 . Directory Boss Daemon 104 is configured to watch Active Folder 102 for file events based on Active Folder 102 's attributes. If a triggering file event is detected, then Directory Boss Daemon 104 will execute Intermediary Application 106 . Intermediary Application 106 is configured to interface with Application 108 and perform actions as defined by User 100 or by policy. Though FIG. 1 illustrates each component being separate, some or all of the components may be in a single device. For example, Active Folder 102 may reside in User 100 's machine. Directory Boss Daemon 104 and Command Line Application 106 may also reside in User 100 's machine. Application 108 may reside on a machine remote from User 100 , such remote machine may include services providing internet services. Further, Intermediary Application 106 may be a command line application, though other applications and methods for performing the defined actions are suitable.
FIG. 2 illustrates a method to set up an active folder. In step 200 , a set up phase is performed. This may include gathering login information, such as email account information, email account password, facebook account information, administrator password for password protected applications, etc. This may also include gathering file trigger information, such as which file events (e.g. modification, creation, deletion, etc.) will trigger a directory boss daemon, which file types (.doc., .jpg, etc.), resize information, among others. The triggering file event need not be determined by a user. In some embodiments, policies or other predetermined file events may be used. Multiple trigger events may be determined, as well as multiple applications and multiple intermediary applications. In step 202 , based on the results of the setup phase, an application and a trigger event are determined. In some embodiments, an intermediary application, such as a command line application may be determined. For example, a command line application with resize dimensions may be determined if resize information was provided in the setup phase. In step 204 , the determined application and trigger event are assigned to a folder stored in a storage device. An authentication process may also be performed to confirm the validity of login information.
In some embodiments, a user may wish to have an active folder which emails a file whenever a file is moved to or created in the folder. A user may create a folder named “Email.” Attributes may be added to the folder, such that a file creation event triggers a directory boss daemon, but not other file events (e.g. deletion, modification, etc.). For example, moving a jpg file into the Email folder would result in triggering a directory boss daemon, but deleting a file would not. File events may further be defined to include only a particular set of file types. For example, creating a .jpg may result in triggering a directory boss daemon, but creating an .xls document may not. Attributes may also include email account information, such as username, password, email service provider (MS Exchange, web email provider, etc.), and recipients, among others. The directory boss daemon may be configured to execute an intermediary application, such as a command line application, plug-in or other suitable application, which interfaces with the email service provider and sends an email to the recipients with the created file attached. After the email has been sent, a log may be recorded. Such a log may include information such as “email sent”, “login failed”, “non-existent recipient,” and “file attachment too large,” among others. The log may also be used to record the history of the active folder, such as total number of files sent via email, total size of email attachments, etc. This provides many benefits over conventional methods of attaching files to email. Conventionally, a user would have to login to an email service provider, locate a file, upload the file to the email service provider, and send the email. Subsequent attachments would again involve logging in, locating a file, uploading the file, and sending the email. With the enhanced technique described herein, a user simply moves a file into an active folder, and the system may automatically send the file as an attachment. Subsequent attachments would only involve adding more files to the active folder.
The above example illustrates only one of many combinations of attributes, directory boss daemons, email service providers, and intermediary applications. Directory boss daemons may be configured to detect several file types (.doc, .mpg, .mp3, etc.) and several file events (creation, rename, modification, access, deletion, etc.). Intermediary applications may send an email with the relevant file attached, may send a simple email notifying the recipients that the relevant file was modified, created, deleted, etc., or may email a link to the file, among others.
FIG. 5 illustrates a method to automate application activity in some embodiments. In step 500 , an active folder in a computer system is monitored for file events. In step 502 , an intermediary application is triggered based on the monitoring. In step 504 , an application is activated based on the triggered intermediary application.
Active Folders may also contain subfolders. Using the example above, separate subfolders may be used for different email recipients, or for different types of files. Different subfolders may also have different triggering events. For example, one active folder may contain many files, and a triggering event may be modification or deletion. If any file in the active folder was deleted or modified, an email notification may go out to the recipient list associated with the active folder. Another active folder may have a file creation triggering event. If any file was moved to the folder or created in the folder, an email may go out to the recipients associated with the active folder, and the file created may be attached to the email.
Active folders are not limited to email applications. A wide variety of applications may be utilized. For example, an application may be the social networking site Facebook (www.facebook.com). The attributes for an active folder named “Facebook” may be similar to those of an email attributes (e.g. file event trigger may be file creation, .jpg files may be monitored for, etc.). However, instead of directing a command line application to an email provider, the command line application is directed to a user's Facebook account. The login information for the Facebook account will required for access, similar to the email active folder. If a picture file is moved to the Facebook active folder, it may trigger a directory boss daemon. The directory boss daemon would execute a command line application resulting in the picture file to be uploaded to the user's Facebook account utilizing the login information.
FIG. 4 illustrates a method to upload pictures to Facebook using a command line application in some embodiments. In step 400 , the command line application starts. In step 402 , it is determined if the command line application is already running. If yes, the flowchart proceeds to step 404 , sending DBUS command to upload the file (e.g. picture). If no, the flowchart proceeds to step 406 , create DBUS services. In step 408 , a worker queue is created. In step 410 , it is determined if the queue is empty. If yes, the command line application exits. If not, the command line application continues to upload files until the queue is empty. In some embodiments, the command line application may be written as a C++ application derived from a common base code that provides the DBUS services and work queue. The command line application may also execute applet scripts written in PHP for applications such as Facebook.
Other websites may be used for the sharing of photos. For example, www.flickr.com may be used, or Picasa provided by Google may be used, among others. Like Facebook, these websites generally require an account and password to utilize their services. The active folders uploading to these websites may require such information during the set up phase.
Many types of files may be used in active folders. For example, active folders may respond to video files (.mpg, .avi, etc.), sound files (.mp3, .wav, etc.), word processing files (.doc, .txt, etc.), among others. When set to respond to video files, active folders may not want to use email as a method to send video files. This may be due to bandwidth concerns. Instead, active folders may be set up to upload video files to www.youtube.com, or other like websites. By uploading video files to such websites, a user may share the video with a much wider audience than email would reach. Similar to the Facebook and email examples illustrated above, a YouTube account will be necessary to upload and share video files. An active folder setup phase for YouTube will include asking for account name and password. The login information may be used by the directory boss daemon or the command line application once a video file is detected (e.g. created, modified, etc. depending on triggering policy) in the YouTube active folder.
Active folders need not be limited to web services. For example, an application may be a photo resize application. The attributes for an active folder named “Resize” may be similar to the Facebook active folder (e.g. file event trigger may be file creation, picture files may be monitored for, etc.). The command line application may be directed toward a photo editing program, such as Microsoft Paint, a java applet, or the command line application may do the resize itself. In some embodiments, the following parameters may be used in the command line application.
ResizePhoto [options and their Parameters] [filename]
-w [path to watermark file]—The File name of the watermark file -x [width]—the width -y [height—the height -o [output]—the output file name Filename—The name of the file to resize
Though the above illustrates a command line application, other applications, such as plugins, among others, are equally suitable.
FIGS. 3A-3C illustrate a method to resize photos using the Iomega Home Media, a product available from Iomega Corporation. In FIG. 3A , a user may create a new active folder by clicking the create button, which is located on bottom left of the active folder tab and “files and photos” sub tab. FIG. 3B illustrates a sample screen shot after the create button has been clicked in FIG. 3A . After selecting the resize photo option in FIG. 3B and naming the folder, FIG. 3C illustrates a screen shot allowing a user to specify dimensions of the resize and watermark. While FIGS. 3A-3C illustrate a few applications associated with active folders, many applications may be used. For example, different web sites (e.g. Picasa, other video sites, etc.) may be used. Further, applications may be used, such as virus scan programs, MS Paint, etc.
Instead of login information, photo resize dimensions may be used. For example, the attributes of 800×600 may indicate that all pictures in the “Resize” folder should have dimension of 800×600. If a picture was created with dimensions smaller than 800×600, the picture may be stretched to meet the required dimensions. Similarly, if a picture was created with dimensions larger than 800×600, the picture may be truncated or compressed to meet the required dimensions.
Other applications may include virus scans, among others. For example, an active folder may have attributes indicating that a virus scan should be performed on a file once it is created or moved to the folder. The attributes may also indicate that a virus scan should be performed daily on all files in the folder.
Active folders may also be used to provide feedback to applications or servers. For example, if an active folder reported high activity and another active folder reported low activity, a server may be configured to allocate more resources (bandwidth, ports, processing power, etc.) to the high activity folder. The levels of activity may be recorded in a log. Applicants may also be ranked according to activity. For example, if a user creates many pictures in the Facebook active folder, but does not put as many videos in the YouTube folder or as many files in a virus scan folder, Facebook may be given a higher rank than YouTube or virus scan. This rank may be used to determine resource allocation to the respective applications, such as processing power, bandwidth, placement on a Windows Start Menu shortcut list, placement in a favorites list in a web browser, etc.
FIG. 6 illustrates a method to allocate resources in a computer system in some embodiments. In step 600 , application activity triggered by an active folder is monitored. In step 602 , applications are ranked based on the monitored activity. In step 604 , resources are allocated to applications based on the ranking.
For the sake of clarity, the processes and methods herein have been illustrated with a specific flow, but it should be understood that other sequences may be possible and that some may be performed in parallel, without departing from the spirit of the invention. Additionally, steps may be subdivided or combined. As disclosed herein, software written in accordance with the present invention may be stored in some form of computer-readable medium, such as memory or CD-ROM, or transmitted over a network, and executed by a processor.
All references cited herein are intended to be incorporated by reference. Although the present invention has been described above in terms of specific embodiments, it is anticipated that alterations and modifications to this invention will no doubt become apparent to those skilled in the art and may be practiced within the scope and equivalents of the appended claims. More than one computer may be used, such as by using multiple computers in a parallel or load-sharing arrangement or distributing tasks across multiple computers such that, as a whole, they perform the functions of the components identified herein; i.e. they take the place of a single computer. Various functions described above may be performed by a single process or groups of processes, on a single computer or distributed over several computers. Processes may invoke other processes to handle certain tasks. A single storage device may be used, or several may be used to take the place of a single storage device. 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. It is therefore intended that the disclosure and following claims be interpreted as covering all such alterations and modifications as fall within the true spirit and scope of the invention. | A method, article of manufacture, and apparatus for storing information in folders is disclosed. In some embodiment, this comprises performing a setup process, determining an application and a trigger event based on the results of the setup process, and assigning the determination to a folder stored in a storage device. In some embodiments, a setup process includes gathering information from an email service provider, or other web services provider. In some embodiments, the setup process may gather information on a local application. | 6 |
BACKGROUND OF THE INVENTION
This invention relates to swimming pools and more particularly to automatic cleaning methods and apparatus which employ one or more jet streams of water originating at or near the interior surface of the pool to agitate dirt that has settled to the floor of the pool so that it may become suspended in the pool water and be pumped through the pool water filtering apparatus.
Existing automatic pool sweeping systems employ powerful water jets projected from sweeper hoses at the bottom of the pool to dislodge dirt and keep the water agitated until the dirt finds its way into the pool outlets.
Recently water outlet heads mounted in the pool side walls and bottom have produced jet streams that are rotated 360 degrees to help agitate and clean the pool water. These outlet heads employ complicated mechanisms to rotate the jet streams.
DESCRIPTION OF THE PRIOR ART
Existing automatic pool cleaning apparatus and methods employing jet streams of liquid to dislodge particles of dirt from the interior surface of the pool have been only partially effective.
U.S. Pat. No. 3,045,829 employs fixed jets, but the number of jets required to clean a pool is so great that a booster pump is necessary. Also, fixed jets stain the interior surface of the pool after a given period of time. The reason for staining is that the pool water normally contains dissolved substances such as copper sulfate, iron oxides, and acids used to purify the water. When these substances are directed over the pool surface for a long period of time, a fan shaped stain will result.
U.S. Pat. No. 3,247,968 employs rotating jets. They either rotate too fast to be efficient or stop and do not rotate at all. Such rotating jet arrangements have the disadvantage that the torque applied to the nozzle when sufficient to overcome the friction of the rotating nozzle at its bearing surface and the friction encountered when rotating through the water will be so great that an undesirable speed of rotation is necessary. Such a high rotational speed of the jets is undesirable since the jet stream is not permitted to achieve a maximum velocity in any one direction and the resulting spiral path is characterized by low velocity and ineffective cleaning action.
U.S. Pat. No. 3,506,489 employs jet streams of liquid that turn off and on in a fixed time relationship. One of the disadvantages of this is that the part of the pool that is not being cleaned is a dead sport and dirt that was suspended in the pool liquid is allowed to settle back to the pool floor. Another disadvantage is that when a jet stream of liquid is turned into a pool it takes several minutes for it to reach out to its full length. Thus, when a jet is turned off and then on again, it is far less efficient in the sweeping of a pool floor than a jet that is sustained continuously.
Other prior art means have been described for causing slow or intermittent rotation of jets in automatic pool cleaning systems. U.S. Pat. No. 3,449,772, for example, describes a jet head incorporating a stainless steel ball which is circulated inside the housing by swirling water. The impact of the ball with a projecting boss incrementally rotates the head. The amount or speed of rotation in this arrangement, however, is highly dependent upon friction and water pressure, both of which are variable with time. U.S. Pat. No. 3,675,252 covers a rotating jet arrangement that utilizes a water turbine coupled to the jet head by a speed reduction gear train to turn the head at low speed. The water supplied to be delivered by the jet also turns the turbine which rotates the head. The disadvantages of this arrangement are the dependence of rotational velocity on pump pressure and the loss in jet pressure contributed by turbine operation.
What is needed is an automatic means for periodically and reliably adjusting the jet direction in small increments, thereby permitting the jet stream to maintain a fixed direction for a sufficiently long period of time to maintain maximum length and velocity. In such a system the available pressure to the jets should not be reduced by energy demands of the jet rotating means. A maximum area may thus be served by a single jet while achieving an optimum cleaning action.
SUMMARY OF THE INVENTION
The present invention overcomes the disadvantages and deficiencies of the prior art apparatus. A unique method and apparatus employed in the invention utilizes air-actuated mechanisms to rotate the several jets positioned about the floor of the pool. Rotational increments of a very few degrees are effected at periodic intervals to step the jets slowly through a full 360 degrees of rotation. Between the stepping intervals the jets remain stationary so that maximum length and velocity are achieved.
It is therefore one object of this invention to provide an improved system and apparatus for automatically cleaning a swimming pool.
Another object of this invention is to provide a pool cleaning system which utilizes one or more water jets positioned strategically about the floor of the pool where they can be directed along the floor surface to stir up dirt and debris which has settled there so that it may become suspended and carried away by the filtration system.
A further object of this invention is to provide such a system in which the jet heads may be stepped automatically in very small increments at periodic intervals so that over a period of time they will be rotated a full 360 degrees.
A still further object of this invention is to provide such a system in which the period of time through which the jet position remains fixed between incremental adjustments is sufficiently long to permit the water jet to reach its full length and maximum velocity, as needed for maximum cleaning effectiveness.
A still further object of this invention is to provide such a system in which the rate of jet advancement or rotation is independent of the pressure available from the filter pump.
A still further object of this invention is to provide such a system in which the pressure available for circulation of water through the jets is not diminished by the energy expanded to rotate the jets.
A still further object of this invention is to provide in such a system a capability for periodically switching the flow of water from one group of jet heads to another group of jet heads, and thereby to concentrate available water flow in specific areas as needed to provide an effective cleaning action.
A still further object of this invention is to provide such a system in which the associated apparatus is totally controlled by air and water pressure.
Yet another object of this invention is to provide the associated apparatus in a form which utilizes no fast-moving parts so that a high degree of reliability and a long operating life may be achieved for the system.
Further objects and advantages of the invention will become apparent as the following description proceeds, and the features of novelty which characterize the invention will be pointed out with particularity in the claims annexed to and forming a part of this specification.
BRIEF DESCRIPTION OF THE DRAWING
The present invention may be more readily described with reference to the accompanying drawing, in which:
FIG. 1 is a diagram of a swimming pool cleaning system incorporating the pool cleaning apparatus of the invention;
FIG. 2 is a cross-sectional view of an air-actuated control mechanism incorporated in the system of FIG. 1;
FIG. 3 is a side view of an actuator incorporated in the mechanism of FIG. 2 as viewed along line 3--3;
FIG. 4 is an end view of the valve plate incorporated in the mechanism of FIG. 2 as viewed along line 4--4;
FIG. 5 is a cross-sectional side view of a jet delivery head incorporated in the system of FIG. 1;
FIG. 6 is a cross-sectional bottom view of the jet delivery head of FIG. 5 as viewed along line 6--6;
FIG. 7 is a cross-sectional view of an air-actuated mechanism which may be substituted for the mechanism of FIG. 2 in a second embodiment of the invention;
FIG. 8 is a side view of a valve plate incorporated in the mechanism of FIG. 7 as viewed along line 8--8 of FIG. 7; and
FIG. 9 is a cross-sectional view of an air-injection mechanism which may be utilized in the second embodiment of the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring more particularly to the drawing by characters of reference, FIG. 1 discloses an automatic swimming pool cleaning system 10 comprising a pump 11, a filter 12, an air-actuated control mechanism 13 and jet delivery heads 14 and 14'. The system 10 is shown installed in a swimming pool 15 which has a drain 16 and a skimmer 17.
The pool 15 is of typical construction and arrangement in which the drain is centrally located in the deepest area of the pool and the skimmer 17 is located at the water surface at one edge of the pool. The jet heads replace or supplement the usual pool inlet ports through which water is ordinarily returned to the pool from the filter 12.
The minimum complement of cleaning equipment ordinarily provided with a home swimming pool includes the pump 11 and the filter 12. In such a minimum cleaning system the pump draws water from the skimmer 17 and from the drain 16 and sends it through the filter 12 and back into the pool through the pool inlet ports. Surface debris from the skimmer 17 and settled debris from the drain 16 are retained in a screen or in the filter 12.
In the improved system 10 the drain 16 and the skimmer 17 are connected by water lines 18 and 19, respectively, to a common line 20 which is connected to the inlet of pump 11. The outlet of pump 11 is connected by a water line 22 to the inlet of filter 12. The outlet of filter 12 is connected by two water lines 23 and 24 to two separate inlet ports of mechanism 13. Mechanism 13 supplies water to heads 14 through delivery line 25 and to heads 14' through delivery line 25'. The rotation of jet delivery heads 14 and 14' is actuated by means of a single water line 27 which originates at mechanism 13, passes serially through actuating vanes in all of the heads 14 and 14' and terminates at the pool skimmer 17.
Mechanism 13 comprises an air chamber 28, a water-pumping chamber 29, a valve chamber 31, an air compressor 32, a pressure-operated control valve 33 and a check valve 34. Chambers 28, 29 and 31 are rectangular chambers positioned adjacent each other and they share a common outer shell. Chambers 28 and 29 are approximately equal in size; chamber 31 is somewhat smaller. Compressor 32 has its outlet connected by an air line 35 to chamber 28. Valve 33 has its inlet connected by line 36 to chamber 28 and its outlet is connected by line 37 to the top of chamber 29. Check valve 34 is serially connected in line 23 between filter 12 and a water inlet port 38 at the bottom of chamber 29. Line 24 from filter 12 entering the top of chamber 31 and line 27 is connected to the bottom of chamber 29. Lines 25 and 25' enter chamber 31 through an outside vertical wall 39 in a manner to be discussed further in connection with the description of chamber 31.
Chambers 28 and 29 are separated by a common wall 41 and chambers 29 and 31 are separated by a common wall 42. Walls 41, 42 and 39 are mutually parallel.
Chamber 29 houses an actuator 43 which is shown in both FIG. 2 and FIG. 3. Actuator 43 comprises a reciprocating lever 44 having a float 45 attached at one end, a ratchet wheel 46 rotationally mounted at the opposite end, and a pawl 47 pivotally attached to lever 44 at a point near the wheel 46 in a manner which permits its free end to engage the teeth of wheel 46. Wheel 46 is rigidly attached to an axle 48 and axle 48 passes rotationally through the ends of a wishbone 49 formed at the end of lever 44 which carries wheel 46. Axle 48 is perpendicularly oriented with respect to walls 41 and 42. It is rotationally mounted at one end to wall 41 and it passes rotationally through a circular bore in wall 42 into chamber 31. At the end of axle 48 which terminates in chamber 31 is attached a cam or flat semicircular plate 51. Plate 51 is perpendicularly attached to the end of axle 48, the point of attachment to plate 51 being located at the center of the straight side of its semi-circular configuration. As shown in FIGS. 2 and 4, lines 25 and 25' are mutually parallel with axle 48 and their terminations inside chamber 31 coincide with a plane that lies at a clearance distance to the right of the right-hand surface of plate 51. Lines 25 and 25' also lie in a common plane with axle 48, and are diametrically opposite each other relative to axle 48. The separation between axle 48 and either of the lines 25 and 25' is somewhat less than the radius of plate 51 so that as plate 51 is rotated by axle 48 it alternately covers the end of line 25 or 25', one at a time, blocking the flow of water to one line, then to the other, etc.
Compressor 32 is capable of delivering approximately one-half cubic foot of air per minute at a pressure approaching fifty pounds per square inch.
In the operation of mechanism 13, valve 33 is initially closed, water has been drained from chamber 29, float 45 rests at or near the floor of chamber 29, and pawl 47 is engaged with wheel 46. Compressor 32 begins pumping air into chamber 28 and chamber 29 begins to fill with water entering at port 38. A low rate of water flow into line 23 accompanies the rise of water in chamber 29, the low rate being intentionally controlled by the adjustment of a valve 52 serially connected in line 23 as shown in FIG. 1. As the operating cycle progresses, the air pressure rises in chamber 28 through the action of compressor 32, and the rising water in chamber 29 causes float 45 to rise, carrying with it the end of lever 44 so that wheel 46, axle 48 and plate 51 are rotated through an angle proportional to the rise in the water level. At some level of pressure reached in chamber 28, valve 33 opens and compressed air rushes from chamber 28 through line 36, valve 33 and line 37 into the top of chamber 29. The rush of air into chamber 29 forces the water from chamber 29 through line 27 and the exhausted body of water from chamber 29 flows successively through the serially connected jet heads 14' and 14, finally leaving line 27 at its open end and exhausting into the skimmer 17. The emptying of water from line 27 is followed by a quantity of air which also exits at skimmer 17. The termination of line 27 at or near the water surface in skimmer 17 prevents the exhausting air from creating an objectionably loud sound as would accompany its release at a greater depth. As valve 33 opens to initiate the rush of water from chamber 29, check valve 34 closes to prevent a reverse flow of water through line 23 into filter 12. As the water is driven from chamber 29, float 45 falls to the floor of chamber 29 with pawl 47 disengaged from wheel 46.
At the end of the cycle just described, the reduced pressure in chamber 28 causes valve 33 to close and another operating cycle ensues. Each successive operating cycle produces a small incremental rotation of plate 51 and delivers a burst of water through line 27.
As plate 51 is thus incrementally turned about its axis water flow from filter 12 and line 24 is periodically shifted from line 25 to line 25', then back to line 25, etc. to be delivered either to jet heads 14 or 14'. Each burst of water through line 27 produces a small incremental rotation of each of the jet delivery heads, 14 and 14'.
FIGS. 5 and 6 show the jet delivery head, 14, 14' comprising a roughly cylindrical housing 53 having its axis vertically oriented. The top of housing 53 is closed by a circular cover 54 having a circular center opening 55. A cylindrical jet nozzle 56 protrudes upward through opening 55, its upward travel being limited by a rim or collar 57. Housing 53 encloses an upper chamber 58 and a lower chamber 59 separated by a horizontal plate 61. Attached to the underside of housing 53 is a turbine assembly 62. Nozzle 56 is supported by an axial shaft 63 which passes vertically downward through plate 61 to a pivotal mounting in the top surface of turbine assembly 62. Shaft 63 is attached to nozzle 56 by a flexible coupling 64 which permits nozzle 56 to retract into chamber 58 if external force is applied.
Turbine assembly 62 incorporates a turbine wheel which may utilize a paddle wheel or other similar configuration such as the cupped wheel 65. Wheel 65 is perpendicularly attached at its axis to a shaft 66 which passes vertically upward through a rotational clearance hole in assembly 62, through chamber 59 to a rotational bearing mount in plate 61. The cup-shaped paddles 67 rotate about shaft 66 in an annular channel 68 which is in communication with line 27 through intake and exhaust ports 69 and 71, respectively. Water entering port 69 follows a path outlined by broken lines 72, flowing past one side of wheel 65 impinging against the concave surfaces of the paddles 67 at that side of the wheel and producing thereby a counterclockwise rotation 73 as shown in FIG. 6. Shaft 66 is coupled by a speed reduction gear 74 to shaft 63 so that a rapid rotation of wheel 65 and shaft 66 produces a very slow rotation of shaft 63 and nozzle 56, and a relatively large number of rotations of wheel 65 may produce only a small angular displacement such as one or two degrees of nozzle 56.
Nozzle 56 has an opening 75 which extends horizontally through its cylindrical wall at a point just above the upper surface of cover 54. Water which enters chamber 58 from line 25 or 25' flows upward through the open lower end of nozzle 56 and horizontally outward through opening 75 so that it sweeps across the floor of the pool in a direction controlled by the instantaneous angular position of the nozzle 56.
It should be noted that pipe 27 rises above the top of housing 29' forming chamber 29 in FIG. 2 so a trap is formed and no water will flow out of chamber 29 until the air therein is released. An incremental rather than a continuous rotation of the jets 56 is thus achieved, with the result that the jet direction remains stationary for a relatively long period of time between the incremental directional adjustments. Ample time is thus allowed for the jet to achieve its maximum velocity and extended length for optimum cleaning action.
The compressor 32 which is utilized in the preferred embodiment just described with reference to FIGS. 1-6 may be eliminated through the incorporation or substitution of the mechanisms or assemblies of FIGS. 7-9.
FIG. 9 shows an air-injection mechanism 80 contained in a cylindrical housing 81 which is divided into an upper chamber 82 and a lower chamber 83 by a horizontal partition 84. The top of housing 81 is closed by a flat plate 85 and the lower flanged end is covered by a flanged plate or cover 86. A flexible diaphragm 87 is interposed between the flanged connection of cover 86 to housing 81 forming a water-tight and air-tight barrier between chamber 83 and the underside of diaphragm 87. An air inlet line 88 enters chamber 82 through plate 85. Air enters line 88 through an air filter 89 and its flow rate is adjustable by means of a screw 91. A pivoting valve assembly 92 is attached to the lower end of line 88, the assembly 92 comprising a lever 93 pivotally mounted at its center to line 88, its one end holding a stopper 94 under the open end of line 88 and its other end pivotally attached to the upper end of a vertical rod 95. Rod 95 passes downward through partition 84 and attached to the center of diaphragm 87. A compression spring 96 surrounding rod 95 urges diaphragm 87 and attached rod 95 downward tending to pivot stopper 94 upward against the open lower end of line 88 to block the entry of air into chamber 82.
A hollow tube 97 connects the interior of chamber 82 with the intake line 20 of the pump 11, and a tube 98 connects the outlet line 22 of pump 11 to the space between the lower side of diaphragm 87 and cover 86.
In the operation of mechanism 80, when the pump 11 is operating, the elevated pressure in outlet line 22 is transmitted to the underside of diaphragm 87 through tube 98 causing diaphragm 87 to be deflected upward, thereby operating valve assembly 92 to open line 88 and admit air into chamber 82. The reduced pressure produced by pump 11 in line 20 draws air from chamber 82 into line 20 and pump 11 mixing it with the water that is dispatched to filter 12 of FIGS. 1 and 7 through line 22.
In filter 12 the entrained air rises to the top and finds its way through a connected line 101 into the air actuated mechanism 102 of FIG. 7.
Mechamism 102 has a pumping chamber 103 and a valve chamber 104 separated by a vertical wall 105.
Chamber 103 has an upper reservoir 106 formed by a shelf 107 which turns upward at one end to form a vertical wall 108. An opening between wall 108 and the outer wall of chamber 103 provides a path for the flow of air or water between reservoir 106 and the main lower portion of chamber 103. A hollow tube 109 opening into reservoir 106 through shelf 107 extends downward therefrom, its open lower end being guarded by a float valve 111 which closes tube 109 when the water level in chamber 103 is sufficiently high and opens tube 109 at lower water levels.
A line 112 opening into the top wall of chamber 103 is connected to line 27 which is the same line 27 as shown in FIG. 1 and which in the embodiment of FIGS. 7-9 also opens into the valve chamber 104 of mechamism 102.
Valve chamber 104 is similar functionally and in its construction to chamber 31 of FIG. 2. An identical construction could be employed but the alternate construction shown here incorporates a variation in the design of the cam or plate identified in this case as cam 113. Instead of the semi-circular plate of FIG. 4 a circular plate is employed with two slotted openings, 114 and 115. Slot 114 lies along the circumference of a circle centered at axle 48 but having a diameter slightly less than that of cam 113. Slot 115 is also circular, centered on axle 48 but with a somewhat smaller diameter than that associated wth slot 114. The slots 114 and 115 cover 180 degrees each and are positioned on opposite sides of axle 48. The two lines 25 and 25' are in this case positioned on the same side of axle 48, one directly above the other. Again the rotation of cam 113 alternately opens one or the other of the lines 25 and 25' to deliver water to jet delivery heads 14 or 14'.
A float operated valve 116 mounted under the entry of line 112 into chamber 103 blocks the opening into line 112 when reservoir 106 is filled with water and opens the entry to line 112 when reservoir 106 is empty or only partially filled.
In the operation of mechanism 102, air accumulated at the top of filter 12 through the action of mechanism 80 of FIG. 9 flows through line 101 into chamber 103 which had been filled with water. Initially the water in chamber 103 holds both valves 111 and 116 closed. As the air rises through line 101 the displaced water flows downward through line 101 into filter 12. Water is retained in reservoir 106 until the level in chamber 103 falls low enough to open valve 111. When valve 111 opens the water drains from reservoir 106 through tube 109 and valve 116 opens. The accumulated air inside chamber 103 at high pressure is now released through line 112 to produce the burst of water flow through line 27 described earlier in connection with the first embodiment of the invention, the burst of water again incrementally rotating the jet delivery heads 14 and 14' of FIG. 1.
An effective automatic pool cleaning system and apparatus are thus provided in accordance with the stated objects of the invention and although but two embodiments of the invention have been illustrated and described, it will be apparent to those skilled in the art that various changes and modifications may be made therein without departing from the spirit of the invention or from the scope of the appended claims. | Apparatus for cleaning a swimming pool wherein one or more automatically controlled water jets are strategically spaced about the floor of the pool, their periodic operation and their direction being controlled by air-actuated means in a manner which optimizes their effectiveness. | 4 |
FIELD OF THE INVENTION
The present invention relates to bus bridges generally and, more particularly, to a protocol converter to access Advanced High-performance Bus (AHB) slave devices using a Management Data Input/Output (MDIO) protocol.
BACKGROUND OF THE INVENTION
The Management Data Input/Output (MDIO) protocol is used in many devices, especially devices using various Ethernet type interfaces. An MDIO bus is a serial bus that can transfer a 16-bit address or a 16-bit data word per frame. The Advanced High-performance Bus (AHB) protocol is used by many peripherals. An AHB bus is a parallel bus that can transfer a 32-bit address and a 32-bit data word simultaneously. It would be desirable for an MDIO bus master to be able to communicate with an AHB slave device.
SUMMARY OF THE INVENTION
The present invention concerns a method for communicating between a first bus and a second bus. The method generally comprises the steps of (A) recognizing a read operation code in a read frame (i) received from the first bus and (ii) communicated with a first-bus protocol, (B) initiating a read transaction on the second bus using a second-bus protocol different than the first-bus protocol, wherein the initiating occurs earlier than a turn around time in the first-bus protocol that provides a plurality of bit times to respond to the read operation code and (C) transmitting read data received from the second bus on the first bus immediately after the turn around time.
The objects, features and advantages of the present invention include providing a protocol converter that may (i) enable an MDIO bus master to access AHB slave devices using an MDIO protocol, (ii) hide the latency of an AHB read transaction from the MDIO protocol, (iii) convert information between a serial protocol and a parallel protocol and/or (iv) provide compatibility with an AHB-lite specification.
BRIEF DESCRIPTION OF THE DRAWINGS
These and other objects, features and advantages of the present invention will be apparent from the following detailed description and the appended claims and drawings in which:
FIG. 1 is a block diagram of an example implementation of a system;
FIG. 2 is a block diagram of an example implementation of a bridge circuit of the system in accordance with a preferred embodiment of the present invention;
FIG. 3 is a TABLE I of the MDIO protocol; and
FIG. 4 is a block diagram illustrating signal details of the bridge circuit.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to FIG. 1 , a block diagram of an example implementation of a system 100 is shown. The system 100 generally comprises a circuit (or module) 102 , a circuit (or module) 104 , one or more circuits (or modules) 106 a - 106 c, a circuit (or module) 108 , multiple multiplexers 110 a - 110 c, a bus 112 and a bus 114 . The system (or apparatus) 100 may be implemented as a system-on-a-chip circuit. The system 100 may be operational to allow a Management Data Input/Output (MDIO)-based controller to read and write to/from devices that have Advanced High-performance Bus (AHB) interfaces.
The circuit 102 may be referred to as a Station Management (STA) circuit. The STA circuit 102 may be operational as a bus master for the bus 112 . In one example, the bus 112 may be compliant with an Institute of Electrical and Electronics Engineering (IEEE) specification 802.3ae, clause 45, for an MDIO electrical interface. The bus 112 and the circuit 102 may be compliant with other serial bus standards to meet the criteria of a particular application.
The circuit 104 may be referred to as a bridge circuit. The bridge circuit 104 may be operational to translate messages and information between the MDIO bus 112 and the bus 114 . The bus 114 may be compliant with an Advance High-performance Bus (AHB) of an Advanced Microcontroller Bus Architecture (AMBA) specification published by ARM Limited, Cambridge, England. In one example, the AHB bus 114 may be implemented as an AHB-lite bus. In other examples, the bus 114 and the circuit 104 may be compliant with other bus standards to meet the criteria of a particular application.
The circuits 106 a - 106 c may be referred to as slave circuits (or devices). The slave circuits 106 a - 106 c may be operational as slave devices on the AHB bus 114 . Each of the slave devices 106 a - 106 c may be readable and writeable via the AHB bus 114 .
The circuit 108 may be referred to as an address decoder circuit. The address decoder circuit 108 may be operational to generate multiple select signals (e.g., HSELa-HSELc) based on an address value presented by the bridge circuit 104 . A unique select signal HSELa-HSELc may be presented to each of the slave circuits 106 a - 106 c indicating which of the slave devices 106 a - 106 c is being addressed. In some designs, the address decoder circuit 108 may be eliminated (e.g., a design in which all of the slave circuits 106 a - 106 c directly decode the address values to determine participation in bus transactions).
The multiplexers 110 a - 110 c may be operational to multiplex a number of ready signals (e.g., HREADYa-HREADYc) into a ready signal (e.g., AHB_HREADY), a number of status response signals (e.g., HRESPa-HRESPc) into a status response signal (e.g., AHB_HRESP) and a number of read data signals (e.g., HRDATAa-HRDATAc) into a read data signal (e.g., AHB_HRDATA) from the slave circuits 106 a - 106 c back to the bridge circuit 104 . In certain applications, the multiplexers 110 a - 110 c may be eliminated (e.g., in designs having a single slave circuit 106 a ).
The bridge circuit 104 generally comprises a module (or block 120 ) and a module (or block) 122 . The module 120 may be referred to as an MDIO interface module (also called MDIO_TO_AHB_MASTER.V). The module 122 may be referred to as an AHB master module. The MDIO module 120 may be operational to act as a slave device on the MDIO bus 112 at an MDIO slave interface 123 . The MDIO module 120 may also communicate with the AHB master module 122 . While communicating on the MDIO bus 112 , the MDIO module 120 may support an MDIO clause 45 (e.g., ST=> ‘00’). In some applications, the MDIO module 120 may not support an MDIO clause 22 (e.g., ST=> ‘01’).
The MDIO protocol clause 45 generally defines the following opcodes: (i) Address, saves a specified address, (ii). Write, writes a word to the specified address, (iii) Read, reads a word from the specified address and (iv) Read, Post Increment (e.g., Read-Increment), reads a word from the specified address and then increments the address. The address is generally incremented by two bytes (e.g., a 16-bit word) by the Read-Increment opcode.
The MDIO protocol may also define a port (or register) address field (e.g., REGADR) and a device (or physical) address field (e.g., PHYADR) that may be used to address the bridge circuit 104 . A register address value in the field REGADR and a physical address value in the field PHYADR received from the MDIO bus 112 may be latched and compared with an assigned register address value in a signal (e.g., MDIO_REG_ADDR) and an assigned physical address value in a signal (e.g., MDIO_PHY_ADDR), respectively, received through external ports 124 and 126 of the bridge circuit 104 . If both of the bus-received values match both of the assigned values, an internal match signal may be asserted by the bridge circuit 104 and the frame reception continued from the MDIO bus 112 .
The AHB master module 122 may include an AHB cycle request interface 128 to the MDIO slave module 120 and an AHB-lite slave interface 130 to the slave circuit 106 a - 106 c. The AHB master module 122 and the MDIO slave module 120 may exchange information (e.g., address, read data and write data) in multi-bit units (e.g., 16-bit words). The AHB master module 122 and the slave modules 106 a - 106 c may exchange information (e.g., address, read data and write data) in wider multi-bit units (e.g., 32-bit double words). In some embodiments, the address information used on the AHB bus 114 may be 24-bit addresses. In other embodiments, the addresses used on the AHB bus 114 may be 16-bit values or 32-bit values. Since the slave circuits 106 a - 106 c may send and receive data on double word boundaries (e.g., 4-byte boundaries), the lowest two bits in the AHB-bus address (e.g., AHB_HADDR[ 1 : 0 ]) may always be logical zeros. The AHB master module 122 may be responsible for enforcing the last two address bits as logical zeros regardless of what the MDIO slave module 120 provides. Therefore, the 16-bit MDIO addresses may be mapped directly into AHB addresses by dropping the least significant bit (e.g., a logical AND with a value 0xfffe) and shifting the bits left one place, as follows:
AHB_HADDR<=((MDIO_ADDR & 0xfffe)<<1)
The two least significant bits of the AHB address AHB_HADDR may be set to logical zeros. The unused upper bits of the AHB address AHB_HADDR may be padded with all logical zeros, all logical ones or some predetermined pattern.
Referring to FIG. 2 , a block diagram of an example implementation of the bridge circuit 104 is shown in accordance with a preferred embodiment of the present invention. The MDIO slave module 120 generally comprises a shift register 140 , a multiplex module 142 , a finite state machine 144 , a number of write registers 146 a - 146 n, an address register 148 and a synchronizer module 149 .
The shift register 140 may be operational to send and receive data on the MDIO bus 112 in a signal (e.g., MDIO_IO). The data in the signal MDIO_IO may be synchronized to a clock signal (e.g., MDIO_CLK) as generated by the STA circuit 102 . Information in the signal MDIO_IO may be valid on a rising edge of the clock signal MDIO_CLK and remain stable for a predetermined period afterwards. The clock signal MDIO_CLK may be synchronized to a system clock (e.g., SYS_CLK) by the synchronizer module 149 upon reception at the bridge circuit 104 . Operation of the synchronizer module 149 may slightly delay the rising edges and the falling edges of the signal MDIO_CLK. The delays may be insignificant compared with the time that the information in the signal MDIO_IO is valid and stable. As such, the information in the signal MDIO_IO may be in synchronization with the system clock domain. In general, the clock signal MDIO_CLK and the data signal MDIO_IO may be provided to the shift register 140 on separate wires. In some embodiments, separate shift registers may be used for input data and output data.
The MDIO finite state machine 144 may be operational to control the MDIO slave module 120 to act as a slave device on the MDIO bus 112 . The MDIO finite state machine 144 may control the shift register 140 and the multiplex module 142 to direct data and address information. The MDIO finite state machine 144 may also communicate with the AHB master module 122 . A person of ordinary skill in the art would understand how to create the MDIO finite state machine 144 to parse the MDIO frames.
The write registers 146 a - 146 n may each be configured to store a single data element received from the MDIO bus 112 . In one embodiment, the number of write registers 146 a - 146 n may be two. However, additional write registers 146 a - 146 n may be implemented to meet the criteria of a particular application. The address register 148 may be configured to store an address received from the MDIO bus 112 .
The AHB master module 122 generally comprises multiple read registers 150 a - 150 n, an address register 152 and a finite state machine 154 . The read registers 150 a - 150 n may be used to buffer read data received from one of the slave circuits 106 a - 106 c until ready for transmission on the MDIO bus 112 . In one example, the number of read registers 150 - 150 n may be two. However, additional read registers 150 a - 150 n may be implemented to meet the criteria of a particular application. The write data buffered in the write registers 146 a - 146 n of the MDIO slave module 120 may be accessed by the AHB master module 122 when ready to write the data to one of the slave circuits 106 a - 106 c.
The AHB finite state machine 154 may be operational to conduct both read transactions and write transactions on the AHB bus 114 . The AHB finite state machine 154 may also be operational to communicate with the MDIO finite state machine 144 . Communications between the finite state machines 144 and 154 may be used to coordinate flow of data items, address values and other information between the modules 120 and 122 . A person of ordinary skill in the art would understand how to create the AHB finite state machine 154 .
An address signal (e.g., AHB_XFER_ADDR) may be used to carry multi-bit (e.g., 16-bit) address values. The signal AHB_XFER_ADDR may present the address values from the MDIO address register 148 to the AHB address register 152 , one address value at a time. A write data signal (e.g., AHB_XFER_WDATA) may be used to carry multi-bit (e.g., 32-bit) write data items. The signal AHB_XFER_WDATA may transfer the write data items from the write registers 146 a - 146 n to the AHB master module 122 , multiple write data times at a time in parallel. Multiple (e.g., two) read signals (e.g., RDATAHI and RDATALOW) may be received by the multiplex module 142 from the read registers 150 a - 150 n. The signals RDATAHI and RDATALOW may present read data items from the read registers 150 a - 150 n to the multiplex module 142 , multiple read data items at a time in parallel. A request signal (e.g., REQUEST) may be presented between the MDIO finite state machine 144 and the AHB finite state machine 154 . The signal REQUEST may transfer one or more different types of requests/information to the AHB finite state machine 154 . Furthermore, the signal REQUEST may transfer one or more different types of requests to the MDIO finite state machine 148 .
In one example, the write registers 146 a - 146 n may each contain two data bytes (e.g., one word) of write data received from the MDIO bus 112 . The write data may be written from the write registers 146 a - 146 n over the AHB bus 114 to one of the slave circuits 106 a - 106 c. Storing the multi-bit (e.g., 16-bit) data received from the MDIO bus 112 into one of the write registers 146 a - 146 n may be controlled by one or more particular bits of the address value stored in the address register 148 . In one example, a single particular address bit (e.g., MDIO_ADDR[ 0 ]) may be used to distinguish between a write high register 146 a and a write low register 146 b. For example, if the particular address bit in the address register 148 is a logical zero (e.g., X=0), the write data may be stored in the write low register 146 b. If the particular address bit in the address register 148 is a logical one (e.g., X=1), the write data may be stored in the write high register 146 a. In another example, the polarity of the particular address bit may be reversed. Therefore, a logical zero in the particular address bit may result in the write data being stored in the write high register 146 a. A logical one in the particular address bit may result in the write data being stored in the write low register 146 b.
Writing a low data word to the write low register 146 b generally does not cause an AHB transfer. Writing a high data word to the write high register 146 a may cause an AHB transfer to take place. Therefore, a wide (e.g., 32-bit) transfer on the AHB bus 114 may be accomplished by the STA circuit 102 sending the bridge circuit 104 (i) an address frame conveying an address value of the target slave circuit 106 a - 106 c with the particular bit set to a logical zero, (ii) a write frame with the low data word, (iii) another address frame having the address value with the particular bit set to the logical one and (iv) another write frame carrying the high data word.
In another embodiment, the AHB bus 114 may be four times wider than the MDIO bus 112 (e.g., the AHB bus 114 has a 64-bit data path). To transfer 64 bits of write data, the STA circuit 102 may use two particular address bits to distinguish among the four 16-bit words of write data on the AHB bus 114 . Therefore, the STA circuit 102 may generate additional address frames and additional write frames to move four 16-bit write data items to the bridge circuit 104 via the MDIO bus 112 .
If the highest data word is written without the lower data word (or words) being previously written, an error is generally indicated by asserting an error signal (e.g., MDIO_TO_AHB_ERROR) at an output 129 . The error signal may be cleared by (i) assertion of a reset signal (e.g., RESET) and/or (ii) writing a low data word. Other mechanisms may be implemented to clear the error signal MDIO_TO_AHB_ERROR to meet the criteria of a particular application.
Requesting a read generally causes an AHB read to take place. In one embodiment, if the particular address bit is set to “low” (e.g., MDIO_ADDR[ 0 ]==0), the low bytes of read data may be sampled from the read low register 150 b and returned to the STA circuit 102 via the MDIO bus 112 . If the particular address bit is set to “high” (e.g., MDIO_ADDR[ 0 ]==1), the high bytes of read data may be sampled from the read high register 150 a and returned to the STA circuit 102 via the MDIO bus 112 . In another embodiment, the polarity of the particular address bit may be reversed. As such, if the particular address bit is a logical zero, the read data from the read high register 150 a may be sampled and returned. If the particular address bit is a logical one, the read data from the read low register 150 b may be sampled and returned. The STA circuit 102 may command a read transaction on the AHB bus 114 by sending the bridge circuit 104 (i) a first address frame having an address value of the target slave circuit 106 a - 106 c with the particular bit set to a logical zero, (ii) a read frame to return the low read data, (iii) a second address frame with the address value having the particular bit set to a logical one and (iv) another read frame to return the high read data.
In other embodiments, the AHB bus 114 may have a data path four time wider than the MDIO bus 112 (e.g., the AHB bus 114 may have a 64-bit data path). To transfer 64 bits of write data, the STA circuit 102 may use two particular address bits to distinguish among the four 16-bit words of read data on the AHB bus 114 . Therefore, the STA circuit 102 may generate additional address frames and additional read frames to read four 16-bit write data items from the bridge circuit 104 .
The AHB read transactions generally take place during a “turn around” time of the MDIO transfer protocol. The turn around time may provide a slave device (e.g., the MDIO slave module 120 ) on the MDIO bus 112 with one or more bit times of the clock signal MDIO_CLK to prepare the requested read data for transmission. In one example, the MDIO slave module 120 may have two bit times to prepare the requested read data. Whenever the clock speed of the AHB bus 114 is substantially more than an order of magnitude faster than the MDIO_CLK speed for the MDIO bus 112 , sufficient time should be available to meet the turn around time criteria of two bit times. For example, an AHB bus clock speed at least 20 times faster than the MDIO_CLK speed generally allows read data to be moved from the slave circuits 106 a - 106 c to the bridge circuit 104 before the MDIO read frame is ready to transfer the read data. If the read transfer does not take place in time, the error signal MDIO_TO_AHB_ERROR may be asserted.
Requesting a read-increment type of read transaction generally causes the address stored in the MDIO address register 148 to be incremented after the read data has been transferred on the MDIO bus 112 . The address value increment generally results in the next several (e.g., two) read data bytes being referenced by a subsequent read frame on the MDIO bus 112 . As such, the STA circuit 102 may command a read transaction by sending a sequence of (i) an address value having the particular bit set to access the low read data, (ii) a read-increment frame to return the low read data then incremented the address value and (iii) a read frame to return the high read data.
In one embodiment, the AHB bus 114 may have a data path four times wider than the MDIO bus 112 (e.g., the AHB bus 114 may have a 64-bit data path). Therefore, the STA circuit 102 may generate additional read-increment frames to return the additional read data items. For example, the STA circuit 102 may generate an address frame having two particular address bits pointing to a lowest word of a read data item. The STA circuit 102 may then generate three successive read-increment frames to read the three lowest words. Finally, the STA circuit 102 may generate a read frame to read the highest (e.g., fourth) word of the read data item.
The following AHB bus fields may be constrained for the system 100 :
field TRANS=>NONSEQ (e.g., 2′b10) or IDLE (e.g., 2′b00)
field HBURST=>SINGLE_XFER (e.g., 3′b000)
field HSIZE=>4-BYTES (e.g., 3′b010)
In other embodiments, the above fields may be constrained differently to meet the criteria of a particular application.
Both modules 120 and 122 generally use the signal SYS_CLK as a basic clock. The modules 120 and 122 may be reset by assertion (e.g., a low voltage) of the signal RESET. The signal RESET may be an asynchronous set (e.g., asserted) and a synchronous reset (e.g., deasserted). In other embodiments, the signal RESET may be synchronously set (e.g., asserted) in synchronization with the clock signal SYS_CLK.
The MDIO module 120 may use the clock signal MDIO_CLK to read the data signal MDIO_IO from the MDIO bus 112 . In some embodiments, the clock signal MDIO_CLK may be implemented as a 2.5 MHz to 20 MHz clock. The shift register 140 may detect rising edges of the signal MDIO_CLK. The clock signal MDIO_CLK may also be used to control state transitions in the MDIO finite state machine 144 .
Referring to FIG. 3 , a TABLE I of the MDIO protocol is shown. The TABLE I generally illustrates support for the clause 45. The MDIO protocol may define multiple frame types (e.g., Address, Write, Read and Read-Increment). Each frame generally comprises a preamble (PRE) field, a start of frame (ST) field, an operation code (OP) field, the register address (REGADR) field, the physical address (PHYADR) field, the turn around time (TA) field, an address/data field and an idle field. The letters “PPPPP” generally represent a variable value in the physical address field PHYADR. The letters “EEEEE” generally represent a variable value in the register address field REGADR. The letters “AAA . . . AAA” may represent a variable address value in the address/data field. The letters “DDD . . . DDD” generally represent a variable data value (e.g., read or write) in the address/data field. The letter “Z” may indicate a tri-state high impedance value and/or a don't care bit in the frame.
The MDIO state machine 144 may be designed to walk thru the various states of an MDIO frame. The start of frame field ST bits in an MDIO frame should be ‘00’ for the condition “CLAUSE_ 45 _R” to be asserted. The operation code OP bits in the MDIO frame may shifted in by the shift register 140 and saved for later use. A physical (device) address value in the field PHYADR of the MDIO frame and a register (port) address value in the field REGADR of the MDIO frame may be compared with the assigned physical address value in the signal MDIO_PHY_ADDR and the assigned register address value in the signal MDIO_REG_ADDR. Matches generally indicate that the MDIO frame is intended for the bridge circuit 104 . An internal start signal (e.g., AHB_XFER_REQUEST), which is a portion of the signal REQUEST, may be asserted to initiate a transfer assuming that “CLAUSE_ 45 _R” is true and an the physical address and register address matches exist. In some embodiments, only the physical address value in the MDIO frame may be compared with the physical address value in the signal MDIO_PHY_ADDR. A match of the physical address and the physical address value in the signal MDIO_PHY_ADDR may indicate that the MDIO frame is destined for the bridge circuit 104 . In other embodiments, only the register address value in the MDIO frame may be compared with the register address value in the signal MDIO_REG_ADDR. A match of the register address and the register address value in the signal MDIO_REG_ADDR may indicate that the MDIO frame is destined for the bridge circuit 104 .
For an address cycle, the 16 address bits may be stored locally in the MDIO address register 148 . For a write cycle, the particular address bit (e.g., MDIO_ADDR[ 0 ] bit) is generally used to store low write data (e.g., MDIO_ADDR[ 0 ]=0) and high write data (e.g., MDIO_ADDR[ 0 ]=1). After the high write data is written into the write high register 146 a, an AHB write transfer may be initiated by the AHB master module 122 sending the contents of all of the write registers 146 a - 146 n to the AHB bus 114 .
For a read (or read-increment) cycle, the AHB read transfer is generally started at the beginning of the TA 0 cycle of the MDIO protocol. Availability of the read data from the AHB master module 122 at the end of the TA 1 (second turn around) cycle may be expected by the MDIO slave module 120 . In some embodiments, the AHB read transfers may be started earlier in the read (or read-increment) cycle. In one example, the AHB read cycle may start immediately upon detection of a read or read-increment operation code (e.g., OP=“11” or OP=“10”). In another example, the AHB read cycle may start during or after reception of the physical address field PHYADR from the MDIO bus 112 . In still another example, the AHB read cycle may start during or after reception of the register address field REGADR from the MDIO bus 112 and before the TA 0 cycle.
The MDIO specification generally defines the signal MDIO_IO as a bidirectional, tri-state signal. If tri-stating is not implemented, an input signal (e.g., MDIO_IN) may be used as a received data signal and an output signal (e.g., MDIO_OUT) may be used as a transmitted data signal. An enable signal (e.g., MDIO_ENABLE) may be asserted whenever the signal MDIO_OUT signal would be driven as the signal MDIO_IO. The timing of transmitted data in the signal MDIO_OUT generally matches the timing in the MDIO specification.
The AHB master module 122 generally runs off the system clock signal SYS_CLK (e.g., 250 MHz). Since the AHB bus 114 may be approximately 20 to 100 times faster than the MDIO bus 112 , an AHB read cycle generally takes place and the read data may be returned in time for the MDIO module 120 to respond to a read frame. As such, a latency of the AHB read transaction may be hidden from the MDIO bus 112 .
Referring to FIG. 4 , a block diagram illustrating signal details of the bridge circuit 104 is shown. The ports of the MDIO module 120 generally comprise the following signals:
The signal SYS_CLK may be an input system clock signal. In one example, the signal SYS_CLK may be the same as an AHB bus clock signal (e.g., HCLK). In various embodiments, the signal SYS_CLK may have a frequency of approximately 50 MHz to 400 MHz.
The signal RESET may be a reset input signal. The signal RESET may also be called SYS_RESET_L (e.g., asserted in a logical low state).
The signal MDIO_TO_AHB_ERROR may be an output signal. The signal MDIO_TO_AHB_ERROR is generally asserted to indicate an error. Errors that may occur include, but are not limited to (i) an addressing error (e.g., a high word written without a low word previously written), (ii) an AHB read transfer did not complete in time to return the read data to the MDIO interface and (iii) the MDIO finite state machine somehow got into a “default” state. The default state may be exited by (A) a reset and/or (B) receiving an MDIO address value of 0xffff.
The signal MDIO_CLK may be an input clock signal. In various embodiments, the signal MDIO_CLK may have a frequency of approximately 2.5 MHz to 20 MHz.
The signal MDIO_IN may be an input data signal. The signal MDIO_IN may carry frames into the bridge circuit 104 from the STA circuit 102 . In some embodiments (e.g., where tri-stating may be implemented), the signal MDIO_IN may be part of the signal MDIO_IO.
The signal MDIO_OUT may be output data signal. The signal MDIO_OUT may carry frames from the bridge circuit 104 to the STA circuit 102 . In some embodiments (e.g., where tri-stating may be implemented), the signal MDIO_OUT may be part of the signal MDIO_IO.
The signal MDIO_IO may be a bidirectional data signal. The signal MDIO_IO may convey frames of information to/from the bridge circuit 104 . The signal MDIO_IO may comprise the signals MDIO_IN and MDIO_OUT.
The signal MDIO_ENABLE may be an optional output signal. The signal MDIO_ENABLE may be asserted from one cycle before through one cycle after the signal MDIO_OUT is valid. The signal MDIO_ENABLE may be used to enable a tri-state driver to tie the signal MDIO_OUT and the signal MDIO_IN together externally (e.g., as in a traditional MDIO setup).
The signal MDIO_PHY_ADDR may be an input signal. The signal MDIO_PHY_ADDR generally carries a physical address value used to compare with the PHYADR field of an MDIO frame.
The signal MDIO_REG_ADDR may be an-input signal. The signal MDIO_REG_ADDR generally carries a value used to compare with the REGADR field of an MDIO frame.
The signal REQUEST may be a bidirectional signal. The signal REQUEST may transfer commands and information between the MDIO slave module 120 and the AHB master module 122 . The signal REQUEST may be a top level grouping of other unidirectional and/or bidirectional signals.
A signal AHB_XFER_REQUEST may be an output signal. The signal AHB_XFER_REQUEST may be asserted to start an AHB master operation. The signal AHB_XFER_REQUEST may be a portion of the signal REQUEST.
A signal AHB_XFER_BUSY may be an input signal. The signal AHB_XFER_BUSY may be asserted by the AHB master module 122 while the AHB master module 122 is busy with an AHB transfer. The signal AHB_XFER_BUSY may be part of the signal REQUEST.
The signal AHB_XFER_ADDR may be an address output signal. The signal AHB_XFER_ADDR generally carries an address value from the MDIO slave module 120 to the AHB master module 122 .
A signal AHB_XFER_WRITE may be an output signal. The signal AHB_XFER_WRITE may indicate a read or write operation. The signal AHB_XFER_WRITE may have a logical zero value to indicate a read and a logical one value of to indicate a write. The signal AHB_XFER_WRITE may be a part of the signal REQUEST.
A signal AHB_XFER_RDATA may be an input signal. The signal AHB_XFER_RDATA generally carries read data returned from an AHB read operation. The signal AHB_XFER_RDATA generally comprises the signal RDATAHI and the signal RDATALOW.
The signal AHB_XFER_WDATA may be an output signal. The signal AHB_XFER_WDATA generally carries write data for an AHB write operation. The signal AHB_XFER_WDATA may also be referred to as an AHB write data signal (e.g., AHB_HWDATA).
A signal AHB_XFER_RESP may be an optional input signal. The signal AHB_XFER_RESP generally indicates an AHB transfer response from the slave circuit 106 a - 106 c involved in the transaction (e.g., read or write).
The ports of the AHB master module 122 generally comprise the following signals:
The signal SYS_CLK may be an input system clock. In one embodiment, the signal SYS_CLK may be the same as an AHB bus clock (e.g., HCLK).
The signal RESET may be a reset input signal. The signal RESET may also be referred to as the signal SYS_RESET_L.
The signal AHB_XFER_ERROR may be an output signal. The signal AHB_XFER_ERROR is generally asserted if an AHB error is reported in the response signal AHB_HRESP generated by one of the slave circuits 106 a - 106 c.
The signal AHB_XFER_ADDR may be an input signal. The signal AHB_XFER_ADDR generally carries an address from the MDIO module 120 to the AHB master module 122 .
The signal AHB_XFER_WRITE may be an input signal. The signal AHB_XFER_WRITE generally indicates if the AHB bus transaction is a read (e.g., 0=read) or a write (e.g., 1=write). The signal AHB_XFER_WRITE may be a portion of the signal REQEUST.
The signal AHB_XFER_WDATA may be an input signal. The signal AHB_XFER_WDATA generally carries write data for an AHB write operation.
The signal AHB_XFER_RDATA may be an output signal. The signal AHB_XFER_RDATA generally carries read data returned from an AHB read operation. The signal AHB_XFER_RDATA generally comprises the signal RDATAHI and the signal RDATALOW.
The signal REQUEST may be a bidirectional signal. The signal REQUEST may transfer commands and information between the MDIO slave module 120 and the AHB master module 122 . The signal REQUEST may be a top level grouping of other unidirectional and/or bidirectional signals.
The signal AHB_XFER_REQUEST may be an input signal. The signal AHB_XFER_REQUEST may be asserted to start an AHB Master operation. The signal AHB_XFER_REQUEST may be a portion of the signal REQUEST.
The signal AHB_XFER_BUSY may be an output signal. The signal AHB_XFER_BUSY is generally asserted while the AHB master module 122 is busy with an AHB transfer. The signal AHB_XFER_BUSY may be part of the signal REQUEST.
The signal AHB_XFER_RESP may be an output signal. The signal AHB_XFER_RESP generally carries the AHB transfer response (e.g., either OKAY or ERROR) generated by the slave circuits 106 a - 106 c. The signal AHB_XFER_RESP may be part of the signal REQUEST.
The signal AHB_HADDR may be an output signal. The signal AHB_HADDR may be attached to an HADDR port on each of the slave circuits 106 a - 106 c. The address carried by the signal AHB_HADDR may be padded and adjusted by the AHB master module 122 , as discussed above.
A signal AHB_HWRITE may be an output signal. The signal AHB_HWRITE is generally attached to an HWRITE port of each of the slave circuits 106 a - 106 c.
A signal AHB_HTRANS may be an output signal. The signal AHB_HTRANS may be attached to an HTRANS port on each of the slave circuits 106 a - 106 c.
A signal AHB_HBURST may be an output signal. The signal AHB_HBURST is generally attached to an HBURST port of each of the slave circuits 106 a - 106 c.
A signal AHB_HSIZE may be an output signal. The signal ABH_HSIZE may be attached to an HSIZE port of each of the slave circuits 106 a - 106 c.
The signal AHB_HWDATA may be an output signal. The signal AHB_HWDATA is generally attached to an HWDATA port of each of the slave circuits 106 a - 106 c. The signal AHB_HWDATA may also be referred to as the signal AHB_XFER_WDATA.
The signal AHB_HRDATA may be an input signal. The signal AHB_HRDATA is generally attached to an HRDATA port of each of the slave circuits 106 a - 106 c through the multiplexer 110 c. The signal AHB_HRDATA may be one of the slave signals HRDATAa-HRDATAc.
The signal AHB_HREADY may be an input signal. The signal AHB_HREADY may be attached to an HREADYOUT port of each of the slave circuits 106 a - 106 c through the multiplexer 110 a. The signal AHB_HREADY may be one of the slave signals HREADYa-HREADYc.
The signal AHB_HRESP may be an input signal. The signal AHB_HRESP generally indicates a status of the AHB bus transaction (e.g., OKAY or ERROR) from the slave circuits 106 a - 106 c through the multiplexer 110 b . The signal AHB_HRESP may be one of the slave response signals HRESPa-HRESPc.
The present invention may also be implemented by the preparation of ASICs, FPGAs, or by interconnecting an appropriate network of conventional component circuits (such as conventional circuit implementing a state machine), as is described herein, modifications of which will be readily apparent to those skilled in the art(s).
The various signals of the present invention are generally “on” (e.g., a digital HIGH, or 1) or “off” (e.g., a digital LOW, or 0). However, the particular polarities of the on (e.g., asserted) and off (e.g., de-asserted) states of the signals may be adjusted (e.g., reversed) accordingly to meet the design criteria of a particular implementation. As used herein, the term “simultaneously” is meant to describe events that share some common time period but the term is not meant to be limited to events that begin at the same point in time, end at the same point in time, or have the same duration.
While the invention has been particularly shown and described with reference to the preferred embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made without departing from the spirit and scope of the invention. | A method for communicating between a first bus and a second bus is disclosed. The method generally includes the steps of (A) recognizing a read operation code in a read frame (i) received from the first bus and (ii) communicated with a first-bus protocol, (B) initiating a read transaction on the second bus using a second-bus protocol different than the first-bus protocol, wherein the initiating occurs earlier than a turn around time in the first-bus protocol that provides a plurality of bit times to respond to the read operation code and (C) transmitting read data received from the second bus on the first bus immediately after the turn around time. | 6 |
This is a continuation of application Ser. No. 08/069,096 filed on May 28, 1993, abandoned.
FIELD OF THE INVENTION
This invention relates generally to bioelectronic medical examination apparatus, and more particularly to the type of such apparatus which operates on spectrophotometric principles, particularly by use of electromagnetic energy in the visible and near infrared range. Still more particularly, the invention relates to apparatus of the foregoing kind which is used to obtain clinical examination data from the brain, particularly the human brain, by means of an electro-optical sensor placed on the forehead of the patient, and especially to the determination of cerebral hemoglobin oxygen saturation in this manner.
BACKGROUND
In our earlier U.S. Pat. No. 5,139,025, and in subsequent U.S. Pat. No. 5,217,013, assigned to the same assignee, various sensor configurations and structures are disclosed for use in spectrophotometric clinical examination apparatus, particularly the cerebral oxygen saturation monitor developed by Somanetics Corporation, of Troy, Mich., which uses electro-optical components mounted in such a sensor to emit light energy of selected wavelengths and project the same through brain tissue located behind the torehead by transmissivity through the epidermal layers and underlying bone of the frontal skull, and to detect resultant light energy at certain locations spaced laterally from the point of light introduction by certain predetermined distances. In the first such patent, a relatively rigid "hard" sensor configuration is disclosed which is principally suitable for use on generally flat or very soft, compliant surfaces and media, while in the second such patent a flexible, compliant sensor is disclosed which is suitable for use on various curved surfaces, to which it may be manually conformed, such as for example the human forehead.
As indicated above, the lateral distance between the light source and detectors used in such sensors is of considerable importance, since such distances in effect determine the depth to which the interrogating light spectra will penetrate the underlying physiological tissue, at least to the extent that sufficient resultant light is detectable by the sensors to allow for processing and analysis which will yield meaningful data as to the state, condition, or other such attributes of the internal tissue sought to be analyzed. Prior patentees have also referred to this principle, or effect, at least in one way or another; for example, F. Jobsis refers to this in his earlier U.S. Pat. No. 4,223,680, although he appears to primarily attribute the underlying principle or rationale to the belief (not shared by the present inventors) that the interrogating light spectra will traverse the scalp, skull, and "gray matter" of the brain immediately underlying the skull along a rectilinear path, but will be abruptly reflected along another such path by the "white matter" of the brain, with a small amount of the light being directed back to the source but most of it being deflected orthogonally and passing back out of the head through the skull and scalp, etc. a particular distance away from the source. In point of fact, Jobsis categorically asserts in one or more of his patents that an absolute minimum separation distance of 4.25 centimeters exists in all such cases, which must be observed if the "gray matter" is to be traversed by the examining spectra, and which will thus control the operation of all such devices.
As indicated, the present inventors do not share the opinion just stated, and on the contrary have demonstrated that other factors and principles are involved, and that the transmission of light energy of selected spectra through the brain will essentially exhibit the characteristics of transmission through a highly scattering and partially absorptive media, through which an essentially infinite number of randomly varying transmission paths will occur, all of which, as a general matter, defining a theoretical mean optical path which is arcuately curved, and in the simplest case, essentially a circular arc, between the source and any given detection location, with an exponential decrease in the intensity of the light as a function of the length of the path it has followed to any given point spaced laterally from the point of origin.
Further, the present inventors have previously disclosed the advantages of using two different detectors, or detector groupings, located at mutually different distances from the source of light energy, one being considered a "near" detector and the other a "far" detector, so that the optical response data produced by each could be comparatively analyzed and the effects upon the dam produced by the "far" detector (which samples light that has penetrated more deeply into the subject) can be conditioned so as to in effect eliminate from it tile optical response data which is attributable to the skin, bone, and related skeletal tissue and vascularity, etc., thereby producing data which effectively characterizes only the internal (e.g., brain) tissue. For the most part, however, it was previously thought that the "near" detector should be located in very close proximity to the source, for a variety of reasons. This view is also reflected in the aforementioned patents of Jobsis, at least certain of which also show the use of both a "near" and "far" detector in the same sensor, although the specific reasons for doing so are not considered to be very well, or clearly explained in these patents.
SUMMARY OF THE INVENTION
The present invention reassesses the highly important aspect of source-receiver positioning and relative separation in light of more comprehensive assessment of human anatomical variations at the particular area where the spectrophotometric procedures involved in determining cerebral oxygen saturation are to be employed, i.e., the human forehead area, including the skin and other adjacent dermal layers, skull thicknesses, and variations in forehead geometry, i.e., the extent, nature, and relative location of curvature, together with the nature and presence of tissue and biological substance (e.g., vasculature, pooled blood volumes, other liquids, membranes, etc.) which do or may directly underlie the skin and skull in the forehead region under any and all possible conditions, including injury, trauma, etc. On these bases, the invention provides particular new source-receiver positioning for the sensor which serves as the patient-machine interface, in order to best accommodate the aforementioned considerations.
In a particular and preferred embodiment, the invention provides an improved methodology and sensor component geometry for use in examination of the human brain and determination of the prevalent conditional state of human brain tissue within a relatively defined internal volume of such tissue (i.e., on a regional basis), by use of the completely non-invasive and innocuous procedures made available by spectrophotometric-type apparatus.
More particularly, the present invention provides novel improvements in methodology and apparatus for a cerebral spectrophotometric sensor as referred to above by which the resulting optical response data is assured of representing purely intrinsic brain tissue, i.e., without the effects which result from passage of the interrogating light spectra through the structure and substances disposed outwardly of the brain itself, i.e., the skin, skull, etc., as noted above. In a broader sense, the novel concepts underlying the invention may be applicable to anatomical areas other than the brain, as should be borne in mind in considering both the foregoing and the ensuing comments relative to and descriptive of the invention.
Accordingly, one characterization of the novel method and apparatus provided by the invention is as follows. Light of selected wavelengths is introduced into the subject from a source location on the outside of its periphery, and first and second light-detection locations are selected on the outer periphery at points spaced from one another and spaced from the source location by unequal, but preferably comparable and not greatly disproportionate, first and second distances, to thereby define unequal first and second mean optical paths extending between the source and the first and second detection locations. By so doing, one such path may be considered as generally defining an overall internal area which contains the particular internal region to be accessed and examined, while the other such path may be considered as defining a secondary internal area which is located generally within the overall such area but which does not include such particular internal region (notwithstanding the fact that in reality some lesser percentage of photons received at the particular detection location involved will no doubt have actually traversed a certain amount of the tissue within such particular region, each "mean optical path" merely representing the idealized path of the predominant number of photons received at the corresponding detector location). In particular, the last-mentioned ("other") such path is selected so that the said secondary internal area includes not only the full thickness of the overlying tissue, etc. disposed between the outer surface and the interior subject or body to be examined, but also at least a small portion of the physiological substance disposed therebeyond, i.e., within the said particular internal volume. By then detecting light at such first and second detection locations resulting from that introduced at the source and producing signals representative of the light detected at both such locations, the signals so produced may be processed to obtain optical response data which particularly characterizes only the tissue of the particular internal region or volume, substantially without effects attributable to any of the tissue and biological substance located between that internal volume and the outside peripheral surface.
In a still more specific sense, the invention provides methodology and apparatus for the indicated spectrophotometric-type clinical examination equipment in which particular distance and positioning parameters are provided for the light source and detectors which will accommodate substantially all known variations in human anatomical size and shape and all or most likely conditions encountered in trauma centers, operating rooms, etc., while consistently providing data which is representative of only the desired internal tissue volume, and not of the overlying tissue and substances disposed nearer the perimeter or making up the peripheral boundaries of the subject. In one particular preferred embodiment, specific relative source-detector separation distances and geometry are provided for the aforementioned cerebral oximeter and directly related apparatus.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a pictorial view illustrating the general environment and structure involved in a preferred embodiment of the invention;
FIG. 2 is a front view of exemplary sensor typifying those previously an used in such applications;
FIG. 3 is a pictorial plan view generally illustrating mean optical path distribution extending from a source to various sensor positions on the perimeter of an idealized highly scattering medium;
FIG. 4 is an enlarged front elevational view of a sensor in accordance with the present invention;
FIG. 5 is a first pictorial sectional view representing the human head and showing a first source-detector position arrangement illustrating certain aspects of the invention;
FIG. 6 is a second pictorial sectional view representing the human head and showing a second source-detector position arrangement illustrating certain aspects of the invention; and
FIG. 7 is a third pictorial sectional view representing the human head and showing a third source-detector position arrangement illustrating certain aspects of the invention.
DESCRIPTION OF PREFERRED EMBODIMENTS
Referring now to FIG. 1, an illustrative system 10 for practice of the invention includes a subject 12, which in this preferred example is a human being upon whose forehead 14 is disposed a sensor 16 that includes an electro-optical source to provide the desired examination wavelengths and various receivers to detect resultant light after the same has passed through the patient's forehead and ;portions of the brain. The corresponding electrical signals for operating the sensor 16 are supplied by and coupled to a spectrophotometric apparatus 18 which, in the preferred embodiment, is configured as the aforementioned cerebral oximeter, referred to and described generally in co-pending U.S. patent application Ser. No. 08/006,705, filed Jan. 21, 1993, and in a more particular sense as exemplified by the Model 3100 cerebral oximeter developed by Somanetics Corporation, of Troy, Mich. As will be apparent, the apparatus 18 essentially comprises an appropriately-programmed microcomputer or "personal computer" 20 having a monitor or visual display 22, there being an electrical cable 24 extending from the sensor to the apparatus 20 which preferably includes a small amplifier 26 disposed at a predetermined distance from the subject 12 to provide for both optimal safety considerations and detection signal strength for enhanced processing capability.
An exemplary earlier form of the sensor 16 is illustrated in FIG. 2, wherein it is designated by the numeral 116. Basically, this device may be considered to be essentially the same as that illustrated and described in patent application Ser. No. 711,452, filed Jun. 6, 1991, (now U.S. Pat. No. 5,217,013) which in essence operates generally in accordance with prior U.S. Pat. No. 5,139,025, both of which are assigned to the assignee of this application. As such, the sensor 116 includes a source 128, a first or "near" detector 130, and a second or "far" detector 132, all mounted in a convenient body 134 that is preferably sufficiently flexible and compliant as to be conformable to the actual forehead shape of each particular patient by light manual pressure. It is to be noted that the "near" detector 130 shown in the embodiment of FIG. 2 is in fact positioned very near sensor 128, and in accordance with the aforementioned co-pending application Ser. No. 711,452, the optimum such distance for this separation is described as being in the range of about 8 millimeters. In that configuration, the "far" detector 132 is described as preferably being approximately 23 millimeters from source 128.
As noted previously, FIG. 3 illustrates in a generalized, pictorial sense the distribution of different mean optical paths 36 of light from a source 38 introduced into a highly scattering medium 40 disposed within a perimeter 42. As generally depicted in this figure, each of the mean optical paths 36 is arcuately-shaped, and may be considered as a generally circularly-shaped segment in an idealized, illustrative sense, although more generally being described as "banana-shaped" or "canoe-shaped" in technical literature. Consequently, receivers 44, 44' located at different positions along the perimeter 42 will receive the introduced light spectra along differently-located and differently-curved mean optical paths 36', 36", and it will be apparent that each such path in effect defines a different area (designated A, A' inside perimeter 42, area A being within the totality of area A' but distinguishable therefrom). In a three-dimensional subject, the mean optical paths 36', 36" would in fact constitute a family of mutually adjacent such arcuate segments, and the areas A, A' would in fact constitute internal volumes with arcuately-shaped, somewhat spherical, ovoid sides. Of course, other particular sensor placements, as shown in phantom at 44" and 44'", would have correspondingly longer mean optical paths disposed between them and source 38 defining other and progressively larger such internal areas and corresponding volumes.
With reference now to FIGS. 5, 6 and 7, the analogy to the example shown in FIG. 3 will be more apparent, and its significance more readily appreciated. More particularly, each of these three figures represents a cross-section of a simplified human cranium, taken along a plane passing through the forehead 14. In each case, certain variations are shown in a pictorial schematic sense that occur randomly in various human populations, including differing sizes and degrees of roundness or circularity in the forehead region, and differing thicknesses of skin, skull, and underlying tissue, which are collectively represented by the thickness of the irregular arcuate wall denoted by the numeral 142, 242, 342 in FIGS. 5, 6 and 7, respectively, and referred to collectively herein as the "peripheral wall" (in the case of the brain and similarly-situated organs) or "overlying tissue structure" (in the case of other internal organs) or, in either case, simply the peripheral extremity. Thus, while shown simplistically as a single area in these figures, but in fact representing a plurality of complex biological structures are in fact represented, as mentioned at various points hereinabove.
More particularly, the head 112 shown in FIG. 5 (representing a typical case) has a somewhat broadly rounded forehead 114 and a "peripheral wall" 142 of a nominal thickness. With an electro-optical sensor 216 applied to the forehead area, a pair of circularly-shaped mean optical paths 136' and 136" are produced, which may be analogized to the generally corresponding paths 36' and 36" of FIG. 3, discussed above. As a result, a first internal area A-1 is produced between the source 138 and the "near" detector 144, a second such area A'-1 being similarly produced between the source and the "far" detector 144'. As may be observed, the "near" area A-1 does include a moderate amount of the internal (brain) tissue, designated by the numeral 140, although not as much as the area A'-1.
Considering FIGS. 6 and 7, it may be noted that the head 212 in FIG. 6 is larger and much more broadly rounded than that of skull 112 shown in FIG. 5, with a flatter forehead 214. On the other hand, the skull 312 of FIG. 7 is smaller and more elliptical, with a more sharply curved forehead area 314 than the corresponding examples shown in FIGS. 5 and 6. In addition, the sensor 416 shown in FIG. 7 is somewhat more elongated than the sensors 216 and 3 14 shown in FIGS. 5 and 6. As a result, the shorter mean optical path 236' of FIG. 6 does not in fact enter the brain tissue 240 at all, and even the longer mean optical path 236" hardly enters the brain tissue. Therefore, the volume A-2 sampled by the near detector 244 is disposed entirely within the "peripheral wall" 242, and indeed even the larger volume A'-2 sampled by the far detector 244' primarily consists of the peripheral wall constituents rather than brain tissue 240. Basically, a somewhat opposite condition is illustrated in FIG. 7, in which both of the mean optical paths 336', 336" extend substantially into the brain tissue 340, and the sampled volumes A-3, A'-3 both include substantial amounts of the brain tissue 340, particularly the volume A'-3.
In the preferred processing of output signals from the electro-optical detectors of the sensor, referred to in more detail in earlier U.S. Pat. No. 5,139,025 and co-pending application Ser. No. 08/006,705, filed Jan. 22, 1993, the characteristics of the tissue within the smaller internal area defined by the output signals from the "near" detector are in effect subtracted from the characteristics of the larger internal volume defined by the output from the "far" detector, thereby producing resultant data which is characteristic of a particular internal volume disposed well beyond the peripheral wall, particularly where the "peripheral wall" or "overlying tissue structure" is essentially the same in thickness and characteristic tissue in the area immediately adjacent both such detectors, which is an important consideration within the purview of the invention. That is, with the extensive variations in particular anatomical structure actually encountered between humans of different ethnicity, size, skull thickness, age, vascular structure, etc., variations in the "peripheral wall" or "overlying tissue structure" will certainly occur, not only from one patient to the next, but even in the same patient. Also, as indicated above, significant differences in the degree and type of forehead curvature, etc. are to be expected, rather than the opposite.
Accordingly, as such differences are considered in further detail and explored further, it ultimately becomes clear that the "near" detector should more properly be located closer to the "far" detector than to the source, particularly in the case of spectrophotometric examination of brain tissue, e.g., as applied to a cerebral oximeter as mentioned above, notwithstanding the fact that this is to a considerable extent contrary to prior thinking in this regard. That is, the only way to make certain that the resultant data ultimately obtained does in fact characterize primarily or exclusively internal brain tissue rather than peripheral, epidermal or intervening anatomical substances or structures is to try to make certain that the smaller of the two internal volumes sampled (i.e., that resulting from the "near" receiver output) includes at least the entire thickness of the skin, skull, etc. constituting the "peripheral wall" or boundary, throughout all of the anticipated anatomical variations which may be encountered in peoples from around the world, and in addition, includes at least a minimal amount (and preferably a significant amount) of internal brain tissue within the smaller of the two volumes so sampled.
In point of fact, the present invention recognizes that it is very desirable to have the smaller such internal volume be relatively large in relation to the other such volume, i.e., be almost as large as the other such volume, so that both mean optical paths lie relatively close to one another. By so doing, it becomes much more likely that the thickness and composition of the intervening adjacent biological structure (i.e., the "peripheral wall" or "overlying tissue structure") traversed by photons received at both the "near" and "far" detectors will be the same, or substantially so, and as stated above this is an important factor in achieving accurate results.
At the same time, it is also important to have the "far" detector located at a sufficient distance from the "near" detector to ensure that a significantly different internal volume is sampled by that detector, so that the difference will represent and characterize a meaningfully distinct internal volume, and thereby reliably represent strictly internal tissue situated well within the brain itself. Nonetheless, it must be recognized that the farther either such detector is placed from the source, the more difficult it is to detect sufficient resultant light energy to afford reliable and meaningful processing, bearing in mind that the selected examination wavelengths provided by the source must be accurately representative of those whose selective absorption by reduced and oxygenated hemoglobin is accurately known, and that the amount of power used to generate the resultant light must be maintained at safe and relatively low levels.
With all of the foregoing factors in mind, studies and testing have led to the final conclusion that, for human brain examination, and particularly for cerebral oxygen determination, the "near" detector should be located at least about 20-25 millimeters away from the source, and preferably somewhat further than that, i.e., about 30 millimeters. At the same time, the "far" detector should be positioned at least about 5 to 10 millimeters distant from the "near" detector to guarantee that a distinguishable and different internal tissue volume is in fact sampled by the second such detector, while also assuring that significant detection signal strength will be present. Thus, while a certain range of preferred such positions is potentially present, a specific example of a most preferred such arrangement places the "near" detector at a point 30 millimeters distant from the source, with the "far" detector positioned 10 millimeters beyond, i.e., at a point 40 millimeters away from the source (which is presently considered the maximum such distance which is useful as a practical matter, with commercially available and economically feasible components). This relationship is illustrated in FIG. 4, wherein an enlarged sensor 216 is shown which has its "near" detector 230 disposed at a point which is clearly much further away from its source 228 than is true of the relationship shown in FIG. 2, wherein the "near" detector 130 is clearly much closer to source 128. In point of fact, the "near" detector 230 in the sensor 216 of FIG. 4 is located at a point analogous to the location of the "far" detector 132 of previous sensor 116 shown in FIG. 2, while the "far" detector 232 of sensor 216 in accordance with the invention is actually disposed even further away from its corresponding source than the "far" detector 132 of earlier sensor 116.
In view of the aforementioned particular factors and their corresponding significance, the most preferred embodiment of the present invention utilizes a larger detector (photodiode) for the "far" position than that used at the "near" position, so as to increase the likely amount of photon reception by the "far" detector. Of course, within commercially available components there are at least a certain number of different sizes of photodetectors available, notwithstanding cost variations, and whereas prior sensors were implemented by use of photodiodes having an effective surface area of 7.5 square millimeters for both the near and far detector, in accordance with the present invention the far detector is preferably implemented by use of a component essentially twice the size of that previously used at this location, i.e., a 15 square millimeter photodiode. In other respects, the physical structure of the preferred sensor configuration 216 in accordance with the invention is in accordance with that disclosed and claimed in co-pending application Ser. No. 08/065,140 filed May 20, 1993), commonly owned herewith, since that structure provides significant advantages over others used heretofore. Of course, the particular examination spectra emitted by the source remains the same (i.e., approximately 760 nm and 803 nm), and the source should therefore be implemented in the same manner as that referred to in prior patents and/or applications commonly owned herewith, i.e., by wavelength-specific light-emitting diodes.
It is believed that the significant advantages provided by the present invention will be apparent to and appreciated by those skilled in the art upon consideration of the foregoing disclosure, and it is to be noted once again that an underlying concept is advanced which is specifically different from those addressed by the prior state of the art, notwithstanding the superficially similar attributes. It is to be understood that the foregoing detailed description is merely that of certain exemplary preferred embodiments of the invention, and that numerous changes, alterations and variations may be made without departing from the underlying concepts and broader aspects of the invention as set forth in the appended claims, which are to be interpreted in accordance with the established principles of patent law, including the doctrine of equivalents. | Spectrophotometric apparatus and related methodology, including a sensor having a source and at least two receivers of electromagnetic radiation such as red and/or near-infrared light, which is applied non-invasively to the outer periphery of a patient or other animate test subject to examine a particular internal region to which is disposed beyond a peripheral extremity of specifically indeterminant thickness lying immediately inwardly of the outer periphery of the test subject. The location of the source and detectors test are selected to be at points spaced from one another by unequal first and second distances defining first and second mean optical paths of specifically differing length, with the second such path defining a primary internal area containing the particular region to be examined, the first optical path generally defining a second internal area located in the primary internal area but substantially separate from the particular internal region to be examined, and the first such optical path including the full thickness of a predetermined typical such peripheral extremity plus at least a small portion of the physiological substance immediately therebeyond. Signals are produced which are representative of the radiation detected by the first and second receivers, and such signals are processed to obtain data which particularly characterizes selected attributes of the substance within the particular internal region, substantially without effects attributable to the secondary internal volume, The second receiver is preferably disposed about thirty to forty millimeters from the source, and the first receiver positioned not closer than about twenty millimeters therefrom. | 0 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to a method for generating a low-resolution gray-scale pattern representing a high-resolution original character image.
2. Description of the Related Art
Bilevel representation, or on/off representation, has been used in cathode ray tube display devices, plasma display devices, liquid crystal display devices and various printers to display or print dot matrix patterns of characters. In the bilevel representation, a binary value is assigned to each picture element (pel). Thus, each pel in the matrix represents black (i.e., foreground) or white (i.e., background). However, the bilevel representation in the matrix produces a stair-step appearance along non-vertical and non-horizontal lines. As the resolution of a displayed or printed image decreases, the stepped edges become larger and increasingly displeasing to the viewer.
Display systems utilizing a plurality of gray-scale levels have been developed to provide a more natural display of character. An article "The Display of Characters Using Gray Level Sampling Arrays", John E. Warnock, Communications of the ACM, Vol. 14, No. 3, 1980, pp. 302-307, and U.S. Pat. No. 4,158,200, Charles L. Seitz et al., Burroughs Corporation, disclose the above system utilizing a plurality of different gray-scale levels or levels of luminance.
FIG. 7 shows the concept of a display utilizing different gray-scale levels. A character pattern of a high resolution, such as 88×88 dots/character box, is stored in a font memory. It is assumed that the character pattern is displayed on a display device of a resolution of 11×11 dots/character. In this case, a sampling pattern 21 having 8×8 sampling windows is used. To convert the original character pattern of 88×88 dots to the character image of 8×8 dots, the number of black pels of a portion of the original character image surrounded by one sampling window is counted, and one of eight levels of gray-scale is assigned in accordance with the number of black pels within the sampling window, so that a gray scale pattern 29 is generated. It is used to control the levels of luminance of the display device.
Although a display utilizing gray-scale levels solves the stepped edge problem, it raises a new problem when a relatively complicated character, such as a kanji character including many horizontal and vertical lines, is displayed. Referring to FIG. 14, a kanji character 51 of high-resolution stored in a front memory is shown. In this case a sampling pattern having 16×16 sampling windows is used. In the manner shown in FIG. 7, a gray scale value is assigned to the number of black pels counted in each sampling window to generate a gray scale pattern 52 representing the original kanji character 51. And, the gray scale pattern 52 is supplied to the display device. It is apparent that a displayed pattern using the gray-scale pattern 52 indicates poor quality, includes horizontal lines contacting each other of the same gray levels and indicates inferior readability.
SUMMARY OF THE INVENTION
The invention contemplates a method for generating a low-resolution gray-scale pattern representing a high-resolution original character image. In accordance with the invention, a sampling pattern is generated having plural sampling windows arranged in columns and rows, the number of columns and rows being determined by the resolution of the gray-scale pattern. The sampling pattern is sequentially positioned at plural positions separated by a predetermined distance along a column direction on the original character image to count, at each position, the total number of black pels in predetermined portions of the rows of the sampling pattern. The total number of black pels counted in each of the positions is compared to detect a position at which the largest number of black pels is detected. The sampling pattern is positioned at the detected position on the original character image, and the number of black pels in each sampling window of sampling pattern is counted to assign a gray-scale value to the sampling window.
Preferably the sampling pattern is sequentially positioned at plural positions separated by a predetermined distance along a column direction and a row direction on the original character image to count, at each position, the total number of black pels in predetermined portions of the rows of the sampling pattern and the total number of black pels in predetermined portions of the columns of the sampling pattern. The total number of black pels counted at each position is compared to detect a position at which the largest total number of black pels in the column portions is detected and at which the largest total number of black pels in the row portions is detected.
In a further preferred form of the invention, after positioning the sampling window at the detected position on the original character pattern, the number of black pels in each row and column of the sampling pattern is counted, and the number of black pels in each row is compared to select a row having a larger number of black pels than adjacent rows, while the number of black pels in each column is similarly compared to select a column having a larger number of black pels than adjacent columns. The selected row and column are sequentially positioned at plural positions separated by a predetermined distance along the column direction and the row direction, respectively, on the original character image to count the number of black pels in the row and the number of black pels in the column at each position.
The number of black pels in the selected row at each position is compared to detect a position in a column direction at which the largest number of black pels is detected; likewise, the number of black pels in the selected column at each position is compared to detect a position in a row direction at which the largest number of black pels is detected. The positions of the selected row and column are shifted to the detected positions, and the number of black pels in each sampling window of the sampling pattern counted to assign a gray-scale value to the sampling window.
Preferably, a group of pel lines located at a center portion of the sampling window is used to count the number of black pels in the row or column and the sampling pattern sequentially positioned at plural positions separated by one pel line.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram of a system for performing the operation in accordance with the present invention.
FIG. 2 shows the original character image stored in the buffer memory.
FIG. 3 is a flowchart of the operation for moving the entire sampling pattern in accordance with the present invention.
FIGS. 4A, 4B, 5A and 5B show the shifting of the sampling pattern in accordance with the present invention.
FIG. 6 shows the initial position and the calibrated position of the sampling pattern in accordance with the present invention.
FIG. 7 shows the position of the sampling pattern and the gray-scale pattern obtained in the prior art.
FIG. 8 shows the sampling pattern positioned at the calibrated position and the gray-scale pattern obtained in accordance with the present invention.
FIG. 9 is a flowchart of the operation for moving the particularly selected row or column of the sampling pattern in accordance with the present invention.
FIGS. 10 and 11 show the operation for selectively moving the particularly row or column of the sampling pattern in accordance with the present invention.
FIGS. 12 and 13 show the kanji character pattern and the gray-scale pattern in accordance with the present invention.
FIG. 14 shows the kanji character pattern and the gray-scale pattern in the prior art.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to FIG. 1, a block diagram of a pattern generating system operating in accordance with the present invention is shown.
A font memory 1 stores a set of original character images or patterns of high resolution. It is assumed that the resolution of the original character image is 88×88 dots per character box, and that the original character image is converted to a gray-scale pattern of 8×8 dots or pels per character box.
The pattern generating system can be incorporated in a printer or a display apparatus, and the original character patterns are loaded from a processor into font memory 1.
One of the original character patterns, such as an image of the character B, of 88×88 dots resolution is fetched from font memory 1 and loaded into a buffer memory 2 under the control of a microprocessor 3, as shown in FIG. 2.
The size of the buffer memory 2 shown in FIG. 1 is that of one original character box.
Microprocessor 3 generates a grid-like sampling pattern 21 of 8×8 windows, as shown in FIG. 2, based upon the resolution of the original character pattern, i.e. 88×88 dots, and the resolution of the gray-scale pattern, i.e. 8×8 dots, to be displayed on a display screen. The size of the sampling pattern 21 is equal to the size of one character box.
Microprocessor 3 performs the image converting operation shown in FIG. 3. In step 31 in FIG. 3, microprocessor 3 counts the number of black pels in each pel line in the X and Y directions of the original character image to generate a histogram 26 in the X direction and a histogram 27 in the Y direction, as shown in FIG. 2, and stores the histograms 26 and 27 in a histogram buffer memory 4 (FIG. 1).
The operation proceeds to step 32 of FIG. 3, in which microprocessor 3 positions the sampling pattern 21 at an initial position at which the upper left corner 22 of the sampling pattern is positioned at the upper left corner 23 of the dot matrix or character box of the original character image.
Describing the sampling operation in the row or X direction with reference to FIG. 4A, which is an enlargement of portion 24 of FIG. 2, pel lines 1-11 represent pel lines of the original character image. Microprocessor 3 selects a group of pel lines 4-8 for each row of the sampling pattern 21. Pel line 6 is positioned at the center of the width of a row, as shown in FIG. 4A. Microprocessor 3 counts the number of black pels in the group of pel lines 4-8 of the original character image for each of rows 1 through 8, by referring to the histogram 26 in the histogram buffer memory 4. Microprocessor 3 sums up the number of black pels in each row to generate the total number of horizontal black pels with the sampling pattern 21 at the initial position, and stores the total number in Y direction memory position 0 of register 5.
In the same manner, microprocessor 3 generates the total number of vertical black pels with the sampling pattern 21 at the initial position. More particularly, referring to FIG. 5A, which is an enlargement of portion 28 of FIG. 2, pel lines 1-11 represent the pel lines of the original character image. Microprocessor 3 selects a group of pel lines 4-8 for each column of the sampling pattern 21. Pel line 6 is positioned at the center of the width of a column, as shown in FIG. 5A. Microprocessor 3 counts the number of black pels in the group of pel lines 4-8 of the original character image for each of columns 1 through 8, by referring to the histogram 27 in the histogram buffer memory 4. Microprocessor 3 sums up the number of black pels in each column to generate the total number of vertical black pels with the sampling pattern 21 at the initial position, and stores the total number in X direction memory position 0 of register 5.
The operation proceeds to step 33 (FIG. 3), in which microprocessor 3 sequentially shifts the sampling pattern 21 from the initial position by ±1 pel line, ±2 pel lines and ±3 pel lines in the X and Y directions, and counts the total number of black pels for each position in the same manner as that described for the initial position.
Describing the sampling operation in the row or horizontal direction with reference to FIG. 4B, the sampling pattern 21 is upwardly shifted by one pel line. The sampling window 25A in FIG. 4B shows the upward shift of the sampling pattern 21 by one pel line. Microprocessor 3 selects a group of pel lines 3-7 of the original character image for each row of the sampling pattern 21. Microprocessor 3 generates the total number of horizontal black pels of the sampling pattern 21 at the +1 position, and stores the total number in Y direction memory position +1 of register 5.
To shift the sampling pattern 21 to the +2, +3, -1, -2 and -3 positions, microprocessor 3 selects pel lines 2-6 for the +2 position, pel lines 1-5 for the +3 position, pel lines 5-9 for the -1 position, pel lines 6-10 for the -2 position, and pel lines 7-11 for the -3 position. Microprocessor 3 generates the total number of horizontal black pels of the sampling pattern 21 at each position, and stores them in the respective Y direction memory position of register 5.
Next, microprocessor 3 sequentially shifts the sampling pattern 21 from the initial position by ±1, ±2 and ±3 pel lines in the X direction, as shown in FIG. 5B. To shift the sampling pattern 21 to the above positions, the microprocessor 3 selects pel lines 5-9 for the +1 position, pel lines 6-10 for the +2 position, pel lines 7-11 for the +3 position, pel lines 3-7 for the 1 position, pel lines 2-6 for the -2 position, and pel lines 1-5 for the -3 position. Microprocessor 3 generates the total number of vertical black pels of the sampling pattern 21 at each position, and stores them in the respective X direction memory position of register 5.
The total number of the black pels, Ts, at respective positions is represented by the following formula: ##EQU1## wherein: P: Position of one pel line of the original character image
f(P): The number of black pels on one pel line of the original character image
w: The number of pel lines in one group on either side of the center portion of the row or column of the sampling pattern
t: The number of dots or pels in the X or Y direction of the gray-scale pattern
B: The number of dots or pels in the X or Y direction of the original character matrix or box
S: The shift position.
The range of the shift position in the positive direction or the negative direction is represented by the following formula:
S<B/3t.
In the exemplary case, B=88 and t=8
S<3.67.
Thus, the +1, +2 and +3 shift positions are selected in the positive direction, and the -1, -2 and -3 shift positions are selected in the negative direction. Next, the microprocessor 3, in step 34 (FIG. 3), compares the total number stored in each of the Y direction memory positions +3, +2, +1, 0, -1, -2 and -3 of register 5, identifies one position at which the largest value is stored, and selects the identified position as a calibrated position of the sampling pattern 21 in the Y direction. It is assumed that the distance between the initial position and the calibrated position of the sampling pattern in the Y direction is Sy, as shown in FIG. 6.
Microprocessor 3 also compares the total number stored in each of the X direction memory positions +3, +2, +1, 0, -1, -2 and -3 of register 5, identifies one position at which the largest value is stored, and selects the identified position as a calibrated position of the sampling pattern 21 in the X direction. It is assumed that the distance between the initial position and the calibrated position of the sampling pattern 21 in the X direction is Sx, as shown in FIG. 6.
FIG. 7 shows a gray-scale pattern 29 generated as in the prior art using the sampling pattern 21 positioned at the initial position shown in FIG. 6 without the calibrating operation.
FIG. 8 shows a gray-scale pattern 30 generated by using the sampling pattern 21 positioned at the calibrated position Sx, Sy shown in FIG. 6 in accordance with the present invention.
Comparing gray-scale pattern 29 with gray-level pattern 30 by observing two portions 71 and 72 of the character B, portion 71 is represented in gray-scale pattern 29 by gray-scale value 2 in column 2 and by gray-scale values 5 and 6 in column 3, while in gray-scale pattern 30 portion 71 is represented by gray-scale value 7 in the column 3. Portion 72 is represented in gray-scale pattern 29 by gray-scale values 2 and 1 in column 4 and by gray-scale values 4 and 2 in column 5, while in gray-scale pattern 30 portion 71 is represented by gray-scale values 3 and 4 in row 4. It is apparent that the gray-scale pattern 30 generated in accordance with the present invention is of excellent readability in comparison with the gray-scale pattern 29 generated in accordance with the prior art.
The purpose of the operations shown in FIG. 3 is to entirely shift or move the sampling pattern 21 on the original character image of high resolution. In the entire shift of the sampling pattern 21, the border lines of the sampling windows which pass, at the initial position, within the black lines of the character are shifted so as to position the major portion of the black line(s) of the character between the border lines of the sampling windows. Referring to FIGS. 7 and 8, a border line 73 passes within portion 71 which is the vertical line of the character B before the entire shift of the sampling pattern 21, as shown in FIG. 7, whereby portion 71 is of inferior readability, as shown by the gray-scale pattern 29. After the entire shift of the sampling pattern 21 in accordance with the present invention, portion 71 of the character B is positioned between border lines 73 and 74 of the sampling pattern 21, as shown in FIG. 8, so that portion 71 is of excellent readability, as shown by the gray-scale pattern 30.
In the steps shown in FIG. 3, the position of the entire sampling pattern is shifted on the original character image to detect an optimum or calibrated position in the X and/or Y direction at which the total number of black pels on a group of pel lines at the center portion of each of all rows and/or all columns is the largest value.
The characters are roughly categorized into a first group of characters, e.g. alphanumeric characters, including few horizontal and vertical lines and a second group of characters, e.g. Japanese kanji characters, including many horizontal and vertical lines.
The entire shift of the sampling pattern 21 performed by the operations in steps 31-34 (FIG. 3) improves the readability of the first group of characters. The readability of characters such as kanji characters belonging to the second group is further improved by the next operation described with reference to FIGS. 9-13, in addition to the operations in steps 31-34.
To this end, step 35 (FIG. 3) determines whether or not the character being processed is a character such as a kanji character belonging to the second group. In the case of the alphanumeric character B described hereinbefore, the answer in step 35 is no, and the operation proceeds to step 36, in which microprocessor 3 positions the sampling pattern 21 at the calibrated position Sx, Sy on the original character pattern, as shown in FIG. 6, counts the number of black pels surrounded by each sampling window of the sampling pattern 21, and assigns one of the different gray-scale levels or values 0-7 to the number of black pels of each sampling window, whereby the gray-scale pattern 30 shown in FIG. 8 representing the original character B is generated. Gray-scale pattern 30 is stored in buffer memory 6 (FIG. 1), and is supplied to the display apparatus or printer.
The operation shown in FIGS. 9-13 shifts the position of particularly selected row(s) and/or column(s) in the sampling pattern 21 positioned at the calibrated position Sx, Sy, shown in FIG. 6.
It is assumed that the entire shift of the sampling pattern 21 for a kanji character, as shown in FIG. 10 has been completed by the operations of steps 31-34 (FIG. 3), and that the sampling pattern 21 in FIG. 10 has been positioned at the calibrated position Sx, Sy. In this case, the answer in step 35 (FIG. 3) is yes, and the operation proceeds to step 91 (FIG. 9), in which microprocessor 3 selects the calibrated position Sx, Sy of the sampling pattern 21, shown in FIG. 6.
The operation proceeds to step 92, in which microprocessor 3 selects the group of pel lines passing through the center portion of each row and column of the sampling pattern 21, and counts the number of black pels on the five pel lines for each row and column of the sampling pattern 21 at the calibrated position Sx, Sy. The number of black pels detected in each row and column is shown in FIG. 10. Next, microprocessor 3 compares the number of black pels in row N with the number of black pels in row N-1 and with the number of black pels in row N+1, and compares the number of black pels in column N with the number of black pels in colum N-1 and with the number of black pels in column N+1, to detect the column or row having the number of black pels larger than that of the adjacent ones.
It is assumed that the number of black pels outside the sampling pattern 21 is zero. In the exemplary case shown in FIG. 10, microprocessor 3 detects rows 1, 4 and 7 and columns 2 and 7, as shown by arrows in FIG. 10. Row 1 has a value 150, i.e. the number of black pels, which is larger than the value zero of an upper adjacent row outside the sampling pattern 21 and the value 60 in row 2. Row 4 has a value 100 which is larger than the value 60 in row 3 and the value 60 in row 5. Row 7 has a value 110 which is larger than the value 60 in row 6 and the value 30 in row 8. Column 2 has a value 260 which is larger than the value 0 in column 1 and the value 70 in column 3. And, column 7 has a value 240 which is larger than the value 70 in column 6 and the value 0 in column 8. Therefore, microprocessor 3 selects columns 2 and 7 and rows 1, 4 and 7 as candidate rows and columns to be shifted.
The operation proceeds to step 93 in FIG. 9, in which microprocessor 3 shifts the position of rows 1, 4 and 7 and columns 2 and 7 selected in block 92. Microprocessor 3 performs the shift operation by shifting the position of the five pel lines on the original character image from the position 0 passing through the center of the column or row to the +1, +2, -1 and -2 positions, and counts the number of black pels on the five pel lines at each shift position. FIG. 11 shows the sampling windows at columns 2 and 3 in row 1 of the sampling pattern 21 shown in FIG. 10. Referring to column 2 in FIG. 11, a group of pel lines, i.e. the five pel lines, is initially located at the position 0 and shifted to the positions +1, +2, -1 and -2, and the number of black pels on the five pel lines in each of the positions +2, +1, 0, -1, -2 is counted, and stored in register 7 (FIG. 1). It is apparent from FIG. 11 that the maximum values for column 2 are obtained in the shift positions +1 and +2. From the positions +1 and +2 generating the maximum values, the position +1 nearest to the original position 0 is selected, and stored in the register 7. The same operation as above is performed in column 7, and microprocessor 3 determines that shift position -2 generates the maximum value and stores column 7 and position -2 in the register 7. The process for row 1 is described with referring to FIG. 11, again. It is apparent in FIG. 11 that shift position -2 generates the maximum value for row 1. Position -2 for row 1 is stored in register 7.
In the same manner as that described above, microprocessor 3 determines the maximum value at positions 0 and -1 for row 4, and determines the maximum value at shift positions -1, 0 and +1 for row 7. The original position 0 is selected when the original position 0 generates the maximum value, so that microprocessor 3 stores position 0 in the memory positions labelled "SHIFT" for rows 4 and 7 of register 7, as shown in FIG. 1.
In this manner, microprocessor 3 shifts a group of pel lines within the row or column of the sampling pattern 21 which is selected in step 92, and counts the number of black pels in each position to determine the shift amounts of the row or column.
It is noted that the shift amounts 0 in rows 4 and 7 represent that these rows 4 and 7 are not shifted.
The operation proceeds to step 94, wherein microprocessor 3 shifts row 1, column 2 and column 7 in accordance with the shift values in register 7 (FIG. 1). More particularly, microprocessor 3 shifts row 1 of the sampling pattern 21 by two pel lines in the downward direction, and shifts the adjacent row 2 by one pel line in the downward direction, as shown in FIG. 12. Microprocessor 3 shifts column 2 by one pel line in the rightward direction, as shown in FIG. 12. Microprocessor 3 shifts column 7 by two pel lines in the leftward direction, and shifts the adjacent columns 6 and 8 in the leftward direction, as shown in FIG. 12. The purpose of shifting the adjacent row or column in the same direction is to reduce distortion of the character image.
The operation proceeds to step 95 in FIG. 9, wherein microprocessor 3 positions the sampling pattern 21 at the calibrated position Sx, Sy on the original character image, detected in step 34 (FIG. 3), shifts the rows and column of the sampling pattern 21 as shown in FIG. 12, counts the number of black pels surrounded by each sampling window, and assigns a gray-scale level or value 0-7 to the number of black pels of each sampling window, whereby the gray-scale pattern 41 representing the original kanji character image is generated, as shown in FIG. 12. Gray-scale pattern 41 is stored in buffer memory 6 (FIG. 1) and is supplied to the display apparatus or printer.
FIG. 13 shows the gray-scale pattern 42 which is generated by using the sampling pattern 21 which is positioned at the calibrated position Sx, Sy detected in step 34 in FIG. 3, without the shift of the particular rows and columns shown in FIG. 12.
Comparing the gray-scale pattern 41 with the gray-scale pattern 42, it is apparent that the readability of the uppermost horizontal line, the left vertical line and the right vertical line of the kanji character is remarkably improved.
In the operation shown in FIG. 9, the position of each selected row or column of the sampling pattern at the calibrated position is shifted to the position at which the number of black pels in the selected row or column is the largest value.
The invention thus improves the poor quality or inferior readability of the gray-scale pattern generated from the high-resolution original character image. | A method for generating a low-resolution gray-scale pattern representing a high-resolution original character image. A sampling pattern is generated having plural sampling windows arranged in columns and rows, the number of columns and rows being determined by the resolution of the gray-scale pattern. The sampling pattern is sequentially positioned at plural positions separated by a predetermined distance along a column direction and a row direction on the original character image to count, at each position, the total number of black pels in predetermined portions of the rows of the sampling pattern and the total number of black pels in predetermined portions of the columns of the sampling pattern. The total number of black pels counted at each of the positions is compared to detect a position at which the largest total number of black pels in the column is detected and at which the largest total number of black pels in the row portions is detected. The sampling window is positioned at the detected position on the original character image, and the number of black pels in each sampling window of the sampling pattern is counted to assign a gray-scale value to the sampling window. Characters such as kanji characters consisting primarily of horizontal and vertical strokes are further processed by shifting selected rows and columns to match the sampling pattern. | 6 |
BACKGROUND OF THE INVENTION
This invention generally relates to automatic key duplication, and more particularly a device to help automatically determine key cut attributes.
In the key making art, each lock manufacturer has adopted a number of different key blanks, each with its own unique shape and specific groove characteristics. Further, for each key blank, the manufacturer has assigned one or more known key cut codes that define the manner in which the key blank can be cut to match the manufacturer's lock.
Once a locksmith determines which key blank it is among the thousands made, he must be skilled at tracing or cutting the notches, cuts or bits of the object key into the correctly identified key blank. If the key cuts are not traced precisely, then the new key will not work in the lock.
The manufacturer's key cut codes define the relationship between the cuts and key blank, and between one cut and other. The following characteristics or attributes are representative:
1) the distance from the key shoulder to the center of the first cut;
2) the distance between cuts, distance being measured from the center of one cut to the center of an adjacent cut;
3) the depth of each cut;
4) the angle of each cut;
5) the length of the flat at the bottom of each cut;
6) the distance between the tip and key shoulder.
Once such attributes of an object key can be extracted, recognized, and compared to that which was supplied by an original key manufacturer, and after the appropriate key blank is selected, a new key duplicating the original can be selected and cut.
Various types of key making machines currently exist which identify and utilize a key manufacturer's coding to duplicate a customer's key. However, none of the following patents teaches a method or apparatus that helps to extract object key information absent some means of making physical referential contact with the object key.
U.S. Pat. No. 2,070,228, issued in 1935, is a seminal patent relating to key cut codes. The device disclosed measures relative depth of key cuts using spring-loaded tumblers that make physical contact with key cuts. Analysis of the slope of the key cut is not considered, though. The acquired data is then used by a locksmith to determine an appropriate key code.
U.S. Pat. No. 4,090,303, relating to a key decoding apparatus, discloses a method of determining the original key cuts utilizing manufacturer's predetermined key cut depth and spacing. The key decoding apparatus disclosed employs an index card having sequential indexes thereon corresponding to a predetermined coded depth of the key desired to be duplicated. This card is inserted into a housing and the key to be duplicated is inserted into a slot in the housing where it engages an indexing member which enters one of the key cuts on the key and indicates on the card the coded depth of the key cut. The angle of the cut of the same key cut may also be determined. The remaining key cuts of the key may be decoded in like manner.
U.S. Pat. No. 3,796,130 issued in 1974 to Garner discloses a semiautomatic key duplicating and vending machine. This device requires the customer to place his key into one of a plurality of slots, each slot adapted to receive a key blade of a different cross-section corresponding to the shape of one of the blanks in storage. Selection of the proper slots provides a means for selecting the appropriate key blank in storage and automatically positions such blank for trace cutting a duplicate profile to that of the customer's key. The principal disadvantages of such a device are that smaller keys fit into larger holes, its inability to determine the differences in key blade length or shoulder position which can distinguish one key blank from another, and the fact that this device merely duplicates the cut features of the customer's key which may be overly worn.
U.S. Pat. No. 4,717,294 discloses a key cutting device, which cuts key blanks by employing a set of coded depth keys supplied by the lock manufacturer.
U.S. Pat. No. 4,899,391 discloses a system for identifying an appropriate key blank from a pattern comprised of a plurality of horizontal grooves of a predetermined depth and spacing taken from the image of the front profile of the key. The principal disadvantage of such a device is that it cannot measure depths of cuts and so cannot decode the characteristics of the key cuts.
U.S. Pat. No. 3,442,174 issued to Weiner et al. for a key blank dispensing and cutting apparatus that requires the assistance of the customer in selecting a slot in which to insert the blade of the key. Once having found the slot, the blank identification process is completed. Unfortunately, the apparatus only allows for identification of the profile of the key and does not take into account keys having identical profiles and varying lengths and shoulder positions and smaller keys that fit into larger holes. Moreover, the apparatus is limited to forty-eight known key blanks. Additionally, the selection method disclosed reveals mechanical push rods, one for each of forth-eight key blanks to push a key blank out of its respective key.
Other representative art includes U.S. Pat. No. 5,245,329, 5,050,462; 4,929,129; and 3,358,561.
These above methods and apparatus for automatic key making require skill on the part of the operator to fixture the object key in some fashion.
While unrelated to the key making, art, the following patents are nevertheless of note. U.S. Pat. No. 4,809,341 teaches a method and apparatus used in semiconductor device fabrication for a reticule or mask image, which has a slight modification of reduction or magnification, using a comparison method in which the real image pattern is compared with the pattern produced from design data. U.S. Pat. No. 4,805,224 reveals a pattern recognition method and device employing second order differential analysis of distinctive features. Other art referenced includes U.S. Pat. No. 4,143,582; 4,324,513; 5,120,010; 5,103,120; 4,899,391; and 3,796,130.
U.S. Pat. No. 5,807,042 discloses a system for automatically extracting attribute information by automatically reading an object key and comparing the attributes of the object key with a master pattern memory of known manufacturers' keys. Then it selects the proper matching key blank and cuts it to the original key cut codes established by the manufacturer. Alternatively, the key blank can be trace-cut, duplicating the used attributes of the object key. Alternatively, key cuts hybridizing the key cut features of the object key and key cut codes of a known manufacturer's key may be determined for use with the corresponding key blank. For decoding depth of key cuts this invention may comprise a transparent section on which an object key may be supported which is rotated and a back lighting means is used to pass light through the transparent section and project an image of the object key. From the image received, the position of the longitudinal centerline of the object key relative to a fixed datum is determined and an output signal generated. The object key may then be rotated to align it. Object key attributes may thus be extracted without fixturing or confining the object key in a holder or like device and a correct key blank may be identified.
This system consists of many sensitive mechanical, electrical and rotating, moving optical devices, and as the result will likely be unreliable and inaccurate. This system is also very sensitive to vibration and cannot be made portable, so it cannot be useful in the field, and will need constant adjusting and maintenance by a highly educated specialist.
SUMMARY OF THE INVENTION
A primary advantage of the present invention is to provide an apparatus to help in determining key cut information without having to physically engage each key cut.
Another advantage of the present invention is to provide a device that uniformly, and without skilled intervention, positions a variety of keys for helping to extract key cut information.
In accordance with a preferred embodiment of the present invention, a device to help determine key cut attributes comprises a holding device to uniformly hold an object key, a luminescent device on one side of the held object key and a device on the other side of the object key to store an image of the object key created by the outline created by the luminescent device.
In accordance with another preferred embodiment of the present invention a device for helping to extract key cut information comprises a key holder to position a key vertically between a luminescent light strip and motionless camera to create an outline of the key cuts for storage in a computing device.
Other objects and advantages of the cutting-device will become apparent from the following descriptions, taken in connection with the accompanying drawings, wherein, by way of illustration and example, an embodiment of the present invention is disclosed.
BRIEF DESCRIPTION OF THE DRAWINGS
The drawings constitute a part of this specification and include exemplary embodiments to the invention, which may be embodied in various forms. It is to be understood that in some instances various aspects of the invention may be shown exaggerated or enlarged to facilitate an understanding of the invention.
FIG. 1 is a perspective view of a preferred embodiment of object key holding means and assembly of luminescent light strip, camera and computer of the present invention.
FIGS. 2A, 2 B and 2 C are a side elevation view of a key blank.
FIGS. 3A and 3B are fragmentary front and side views of a preferred embodiment of the object key holding means.
FIGS. 4A and 4B are fragmentary front and side views of a preferred embodiment of the object key holding means of FIG. 3 with key.
FIGS. 5A, 5 B and 5 C are fragmentary front views of a preferred embodiment of the object key holding means FIG. 3 without key and with long and short keys with different handles.
DETAILED DESCRIPTION OF THE INVENTION
Detailed descriptions of the preferred embodiment are provided herein. It is to be understood, however, that the present invention may be embodied in various forms. Various aspects of the invention may be inverted, or changed in reference to specific part shape and detail, part location, or part composition. Therefore, specific details disclosed herein are not to be interpreted as limiting, but rather as a basis for the claims and as a representative basis for teaching one skilled in the art to employ the present invention in virtually any appropriately detailed system, structure or manner.
A standard key 51 as shown in FIGS. 2A, 2 B and 2 C has a head 53 and a shank 54 . For purposes of explanation, flat sides 59 of shank 54 are positioned vertically and shank 54 is extended horizontally in relationship to head 53 . Along flat sides 59 of shank 54 are grooves and indentations 55 . Grooves and indentations 55 are unique to individual manufacturers. Vertical notches 56 along top 57 of shank 54 and, at times, along the bottom 58 of shank 54 , transform the key blank of FIG. 2A into a key 51 uniquely notched for a particular lock. The manufacturer's unique coding system of grooves and indentations 55 are most easily identified in a head-on view of front 52 of shank 54 as shown in FIG. 2 C. It is the front view, which provides the distinctive features, which allow many different devices and methods to distinguish key blanks among manufacturers and among specific manufacturer's product lines. An important aspect of this invention is a key holder that in one of its preferred embodiments, orients the object key into an operative positional relationship before extracting its attributes, leaving the object key independent of constraint.
This invention may comprise a key holder which forms a shadow image of a key side view by holding a luminescent light strip vertically and positions key before light vertically along its longitudinal axis with the key flat side in parallel with light strip. From the shadow image received by camera 30 which optical axis is established in perpendicular with flat key side, the key attributes may be extracted using computer algorithms, not part of the present invention, without rotating, fixturing or confining the object key. Thereafter, the correct measurements and decoding may be done.
Referring more particularly to the drawings in detail wherein like numerals indicate like elements, there is shown in FIG. 1 an automatic key decoder comprised of a key holder 10 , a video camera 30 and a computer 40 . Key 51 to be duplicated is inserted into the key holder 10 , which provides the shadow image of the key side view. Video camera 30 is mounted forward of the key holder 10 so that optical axis is perpendicular to key side front. The shadow image captured by camera 30 passed to computer 40 which stores the image into its memory. Thereafter, and not part of the present invention, a program may be crated that measures the depths of the cuts and decodes cuts.
The key holder 10 is most clearly shown in FIGS. 3A and 3B. The main purpose of the key holder 10 is to hold all keys with different head and length in a true vertical position. The next purpose of the key holder 10 is to hold the luminescent light strip in parallel with the key flat side of key. It is provided that even light will create a distinct shadow image of the key side view. In the illustrated embodiment, luminescent strip is a phosphorescent thin plastic strip may by Luminescence Systems, Inc., part number 30433-1. Key holder 10 has housing 11 mounted on horizontal base 12 . Within housing 11 are four vertical holes with for springs 13 , 14 , 15 and 16 , respectively. The holder has generally V-shaped head 17 , generally V-shaped tip 18 , movable door 19 with spring 20 , fixed door 21 and luminescent light strip 22 , mounted inside housing 11 in vertical position and parallel with holes and spring 13 , 14 , 15 and 16 . V-shaped head 17 and V-shaped tip 18 and have two dowels 23 , 24 and 25 , 26 , respectively to provide vertical movement. Springs 13 , 14 , 15 and 16 provide V-shaped head 17 and V-shaped tip 18 to install a key in an upright position and to move independently from each other. The form of head V-shaped head 17 is fit for all shaped key heads with different from heads and the form of V-shaped tip 18 is fit for the tip of all keys. Movable door 19 is pressed to fixed door 21 with spring 20 for the purpose of clamping key 51 .
As depicted in FIGS. 4A, 4 B and 5 A a short key 51 is inserted in holder 10 until the bottom of the V-shaped head 17 meets housing 11 . Simultaneously, the tip of key 51 will touch the V-shaped tip 18 and push it downward. Before key 51 is installed in holder 10 movable door 19 is opened. After installing key 51 movable door 19 is closed and key 51 will be clamped. Because symmetrical axis's of V-shaped head 17 and V-shaped tip 17 are in one vertical line, the symmetrical axis of key 51 will be placed in a vertical position automatically. In a similar fashion, a long key with a different head can be installed in holder 10 , as illustrated in FIG. 5 C. In this way, key holder 10 provides installation in vertical position for different lengths of and different head shaped keys.
As it was clearly shown in FIG. 4B the luminescent light strip 22 is installed in vertical position and in parallel with flat side of key 51 , which provides even back-lighting of the key and the best shadow image of the key side view. As depicted in FIG. 1, the shadow image is picked up by video camera 30 , which is mounted on horizontal base 12 in front of key 51 so that the camera's optical axis is perpendicular to the flat side of key 51 and provides a good picture of the key shadow image with a very clear key 51 outline. Further, the output signal from camera 30 is input to computer 40 . With the object shadow image captured by camera 30 and processed by computer 40 through an analog-to-digital converter, the attributes of an object key may be identified. Though not part of the present invention, computer 40 may provides a pattern recognition means for recognizing a pixel pattern from an object image of the object key, and for producing a series of code signals with respect to each target pixel from the result of the recognition. The code signals define traits of the recognized pixel pattern for each target pixel, where the pixel patterns define attributes of the object key. Moreover, the computer may be programmed to discriminate between various pixel patterns. A pattern memory in which a set of predetermined master patterns is stored in the ROM of the computer. Each predetermined master code signals define traits of a master pixel pattern, where the master pixel pattern defines attributes of a selected manufacturer's key. The computer may be programmed to compare the code signals from the pattern recognition means with a corresponding master code signal and to produce an identifying signal that defines a corresponding key blank with a predetermined master pattern having master code signals that match code signals from the result of the recognition of the pixel pattern of the object key. This process allows a corresponding key blank matching attributes of a known manufacturer's key to be determined and after that to measure depth of key cuts and decode.
The present invention allows the key to be simply situated within a specified holder, and operates automatically to possibly the key, to extract key attributes so that corresponding key cut codes can be identified for corresponding key blank which can be identified previously. Furthermore, a superior device is disclosed herein is very simple and has only two moving parts, subject to high reliability and accuracy.
While the current mode contemplates the use of one computer to serve all controlling and processing functions, separate, individual controllers could easily be employed.
While this invention has been described in connection with the best mode presently contemplated by the inventor for carrying out his invention, the preferred embodiments described and shown are for purposes of illustration only, and are not to be construed as constituting any limitations of the invention. Modifications will be obvious to hose skilled in the art, and all modifications that do not depart from the spirit of the invention are intended to be included within the scope of the appended claims. | The invention relates to a key decode apparatus for helping to automatically extracting and measurement depths and spacings of cuts an object key and decodes when duplicating an original key. A key holder is provided forming shadow image of a key side view by positioning the original key vertically along its longitudinal axis with the key's flat sides in vertical plane, position an object key between video camera and luminescent light strip. The video camera gets the shadow image of the key side view and sends it to a computer that stores the shadow image in memory that may measure depths and spacings of key cuts and compares with known original key manufacturers information in memory, decodes and sends it to be displayed and can be used in cutting machine for duplicating the key. | 4 |
RELATED APPLICATIONS
This application is a division of application Ser. No. 608,226 filed May 8, 1984,and issued as U.S. Pat. No. 4,552,201, dated Nov. 12, 1985, which is a continuation of application Ser. No. 330,727 filed Dec. 14, 1981.
BACKGROUND OF THE INVENTION
This invention relates to continuous casting machines for continuously casting metal ingot, strip, slab or bars directly from molten metal in a casting region defined between spaced portions of a pair of revolving, flexible, endless casting belts which are moved along with the metal being cast, often called twin-belt casting machines or twin-belt casters.
The invention is described as embodied in the structure and operation of twin-belt casting machines in which the molten metal is fed into a casting region between opposed, portions of a pair of moving, flexible belts. The moving belts confine the molten metal between them and carry the metal along as it solidifies into a bar, strip, slab, or ingot, hereinafter called the "cast product" or "product being cast" or similar words. Back-up means, usually rollers having narrow circumferential ridges or fins support and guide the belts while holding them accurately positioned and aligned as they move along so as to produce the cast metal product.
These back-up rollers are positioned across the machine carriages so as to roll passively when the casting belt grazes each of them under pressure of the head of molten metal and/or the weight of the metal. Their circumferential fins permit the passage of cooling liquid along the respective casting belt without notably impeding heat transfer themselves. The fins have often been made separately from the roller shafts, but in current machines the fins and shafts are now often made integrally as one piece of metal. Vast quantities of heat liberated by the molten metal as it solidifies are withdrawn through the portions of the two belts which are adjacent to the metal being cast. This large amount of heat is withdrawn by cooling the reverse surfaces of the belts by means of the rapidly moving liquid coolant traveling along these surfaces. The edges of the molten product are contained between a spaced pair of side dams in the form of a plurality of blocks strung together on flexible metal straps to form a pair of endless flexible assemblies suitable for containing the molten metal as it solidifies.
Background information on twin-belt casting machines will be found in U.S. patents:
______________________________________U.S. Pat. No. Inventor(s)______________________________________2,640,235 Hazelett2,904,860 Hazelett3,036,348 Hazelett et al*3,123,874 *Division of No. 3,036,348*3,142,873 "*3,228,072 "3,041,686 Hazelett et al3,167,830 "3,310,849 "3,828,841 "3,848,658 "3,864,973 Petry*3,921,697 *Division of No. 3,864,9733,865,176 Dompas et al*3,955,615 *Division of No. 3,865,176*4,155,396 "3,878,883 Hazelett et al*3,949,805 *Division of No. 3,878,883*3,963,068 "3,937,270 Hazelett et al*4,002,197 *Division of No. 3,937,270*4,062,235 "*4,082,101 "3,937,274 Dompas4,092,155 Dompas et al4,150,711 Hazelett et al______________________________________
In machines of this type, the moving belts are thin and are cooled by substantial quantities of liquid coolant, usually water containing corrosion inhibitors. This coolant withdraws heat through the casting belts and serves to cool the metal from its molten state as it enters at one end of the machine causing it to solidify as it passes through the machine.
The molten metal pushes outwardly on the belts due to metalostatic pressure or "head". Solidification of the metal product takes place from outside to inside so that, through some of its passage through the machine, it is in the form of a solidified shell having a molten, constantly decreasing, interior volume. It will also be understood that, as the metal cools and solidifies, it shrinks. The shrinkage is very slight but, nevertheless, is sufficient to cause surface regions of the metal sometimes to pull away from the moving belts or from the side dams. When this separation between areas of the metal surface and the cooling surface occurs, non-uniform cooling is caused, which results in non-uniformities in the parameters of the casting region and in non-uniformities in the cast product.
This invention in certain aspects is especially applicable to casting machines which produce ingot or slab of a width in excess of 25 inches (635 mm). Such twin-belt casting machines are generally inclined downward in use, so as to result in a head -- that is, a static pressure -- of liquid metal in order to fill out the casting region, i.e. the mold cavity, and to thereby press the casting belts decisively against their back-up supports. Further, by use of open-or closed-pool pouring technique, the entry of molten metal into the machine is facilitated by operating the machine at some downward incline. The aforesaid head of molten metal depends on the angle of incline, the density of the molten metal being cast, and the distance to the point of final solidification in the machine.
The force of such liquid metal head is exerted upon the casting belts and thence upon the guides or back-up supports for the belts, which I commonly call the mold back-up. Most immediately, this back-up consists of transversely disposed finned back-up rollers. These rollers and their supports have previously been made rigid in order that the ingot or slab of accurately defined and controlled gauge may be cast. The headers bearing liquid coolant can be made to serve the additional duty of providing rigid supports for the back-up rollers. Some wide machines have in their carriages central longitudinal beams or sills to lend their additional rigidity to the back-up system, for resisting the force of the molten metal to be counteracted as it presses outwardly on the wide casting belts.
The very rigidity of the above described prior art back-up means can combine with the shrinkage inherent in the freezing and cooling of the product being cast to allow air spaces to intervene between the freshly cast surface and the casting belts. These intruding spaces substantially reduce the rate of heat transfer and may render it non-uniform, with a corresponding effect on the rate and uniformity of product cooling and solidification. The reduced rate and uniformity of cooling limits the production rate, or else it requires the use of longer casting machines than would otherwise be needed.
An associated problem with the aforesaid air spaces or gaps occurring between the cast metal surface and the mold surfaces defining the casting region is the consequent degradation of the desired fine, quick-chilled crystalline structure in the cast product into coarser crystals. Such air spaces or gaps can permit the localized remelting of the cast product with consequent bleeding, or sweating of molten material from the previously cast shell itself and/or from the molten metal inside of the shell causing segregation and/or porosity in the cast product. This reheating or remelting will not occur if good mold contact is maintained.
Problems of local excess pressure can occur with a rigid mold when excess thickness is somehow frozen locally. Thus, the relatively thin casting belts will become locally overheated with a corresponding localized area of increased heat transfer due to the high localized belt pressure against the partially solidified product. Also, if a frozen piece of metal of excess thickness is inadvertently drawn into the caster, a slitting of the belt by the narrow fins of the back-up rollers or considerable damage to the precise, rigid mold back-up mechanisms can result.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide systems for continuously casting metal products of high quality directly from molten metal wherein flexibility and control of the transverse shape of the casting region are provided.
Continuous casting systems are advantageously provided wherein the contact pressures between the casting belts and the metal product are controlled and are maintained along the length of the metal to insure uniform heat extraction from the solidifying metal product.
One preferred method of shaping the casting region by action of the back-up system is to arrange for constant parallel thickness in the upstream casting region, before the product being cast is solidified enough to retain its shape, and to allow springy bowable rollers and back-up supports to converge in the downstream portion of the casting region as the largely solid product contracts due to loss of heat.
It is convenient in twin-belt casting machines to make structural use of the transverse headers carrying the cooling liquid to the nozzles which apply the coolant over the casting belts. This convenience is important in view of the lack of space for transverse beams in the belt carriages. In downstream areas of the carriages where less coolant is needed because the product has already formed its solidified shell, there is room for such special transverse beams. The relative bowability of such transverse support beams and coolant headers enters into the total effective bowability of the array of back-up rollers.
There are various aspects of the systems of the present invention for shaping the casting region. In certain aspects, the "head" of the molten metal is predetermined and is used as the driving force for bowing or deflecting the back-up rollers and their support systems in one carriage only, preferably those in the upper carriage while the back-up rollers and support systems in the other carriage are rigid; and predetermined bowability is intentionally provided in the back-up rollers and in their support systems in said one carriage for responding to this force of the head of molten metal, while the back-up rollers in the other carriage are rigidly constrained. In certain other aspects mechanical adjustment means are used for applying bending forces to the back-up rollers and/or to their support systems for producing bowing of the back-up rollers in one or both carriages for shaping the casting region. In certain additional aspects, remotely controllable bowing means are used for controllably applying bending forces to the bowable back-up rollers in one or both carriages for shaping the casting region.
In accordance with certain aspects of the present invention a first one of the casting belts is flexibly constrained in a predetermined relationship versus the molten metal head values occurring at different locations in the downwardly inclined casting region for enabling this first belt to bow transversely away from the casting centerline due to the predetermined molten metal head values occurring at the various locations, with the second casting belt being rigidly constrained and being transversely bowed toward the casting centerline in a predetermined inward convex configuration that compensates for the various displacements of the flexibly constrained belt, resulting in a uniform transverse cross section for the cast product, while providing improved casting parameters.
Among the advantages of this invention are those resulting from continuously casting metal product directly from molten metal wherein the shape and contact pressure and parameters of the belt supports may be controlled by manual adjustment or by remote control.
In carrying out this invention in certain illustrative embodiments thereof, systems are provided for casting metal product directly from molten metal in order to promote uniform heat transfer from the cast metal to the belts which are continuously liquid cooled. The upper back-up rollers are selectively bowed down either by manual adjustment or by remote control, and the lower back-up rollers are allowed to yield or "float", or vice versa. The systems as disclosed include intentionally rigidizing the upper or lower back-up rollers or sections thereof while the back-up rollers on the other side are allowed to flex in predetermined amounts with the surface of the casting. These systems include bowing both sets of the back-up rollers either inwardly or outwardly; bending structural frame members which are in support relationship with the rollers for flexing the rollers to control belt contour and belt contact with the cast product, etc.
The maintenance of contact between the casting belts and the cast product is controlled by either manual adjustment or remote actuation. In any of the systems the mold configuration may be tapered from the upstream to the downstream end of the continuous casting machines for compensating for shrinkage in the solidifying metal and for providing predetermined mold contact pressures and heat transfer characteristics.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention, together with further objects, aspects, advantages and features thereof will be more clearly understood from a consideration of the following description taken in conjunction with the accompanying drawings in which like elements will bear the same reference designations throughout the various FIGURES:
FIG. 1 is a perspective view of the input or upstream end of a continuous casting machine embodying the present invention, as seen looking toward the machine from a position in front of and outboard beyond the outboard side of the two belt carriages.
FIG. 2 is an elevational view, partly broken away and in section, of a prior art machine as seen looking toward the outboard side of the two belt carriages, showing the casting region downwardly inclined at a predetermined angle of inclination.
FIG. 3 is a cross-sectional view of portions of the two belt carriages of the prior art machine including the liquid coolant headers, back-up rollers, casting belts and side dams showing such back-up means and the associated belts and side dams rigidly defining the casting region.
FIG. 4 is a top or plan view of the lower carriage of this prior art machine with the belt and parts of other elements cut away for revealing the structure.
FIG. 5 is a partial side view of this machine enlarged as compared with FIG. 2; for convenience of illustration the casting region is shown horizontal, but it is to be understood that the casting region is inclined downwardly as shown in FIG. 2.
FIG. 6 is a transverse sectional view of the casting region, showing a segmented back-up roller below the lower casting belt, with the segments disposed along a shallow, convex upward arc, in opposition with a flexible back-up roller above the upper belt as it would appear under the pressure of a head of molten metal exerting force from within the casting region between the belts.
FIGS. 7A, 7B and 7C show an enlarged elevational view of a three-segment back-up roller with integral circumferent fins.
FIG. 8 is a further enlarged partial sectional view of a portion of FIG. 6 showing the means for interconnecting the adjoining ends of two segments of a segmented back-up roller.
FIG. 9 is a view similar to FIG. 6 showing intermediate, flexible snubbing bearing back-up means for the flexible back-up roller for providing predetermined control of its degree of flexibility.
FIG. 10 is a transverse section of a twin-belt caster in which the belt shape and contact control is provided by transversely downwardly bowing the upper back-up rollers and by mechanical adjustment and allowing the lower back-up rollers to yield.
FIG. 11 is a transverse section of a twin-belt caster as illustrated in FIG. 10 showing another mechanical adjustment means.
FIG. 12 is a transverse section similar to FIG. 11 in which the mechanical adjustment for the back-up rollers includes a compliance member. FIG. 12A is an enlargement.
FIG. 13 is a transverse section of a twin-belt caster similar to FIGS. 10, 11 & 12 illustrating remote control bowing of the back-up rollers using fluid cylinder actuation.
FIG. 14 is a transverse section of a twin-belt caster illustrating the use of rigidly supported lower back-up rollers with a stiffened center section in the bowed upper back-up rollers for control of belt contact with the product being cast.
FIG. 15 is a transverse section of the caster of FIG. 14 illustrating the use of remote control for belt contact control.
FIG. 16 is a longitudinal, elevational section of the casting region illustrating the use of a selectively tapered mold configuration along the casting region.
FIG. 17 is a transverse section of a twin-belt caster employing symmetrical inward bowing on both the upper and lower back-up rollers by remote control through fluid cylinder actuation.
FIG. 17A is a modification of the system of FIG. 17.
FIG. 18 is a transverse section of a bar-type twin-belt caster illustrating the casting zone before shrinkage of the product being cast.
FIG. 19 is a transverse section of the bar caster shown in FIG. 18 after shrinkage has occurred, illustrating piston rod actuation for bending the back-up rollers to maintain belt contact in the downstream portion of the casting region.
FIG. 20 is a transverse section of a wide caster illustrating the bending of a structural frame member in order to bow the back-up roller supported by such frame member.
FIG. 21 is a transverse section of a wide caster similar to FIG. 20 utilizing a more bendable (compliant) member in order to bow a stiffer frame member in order to provide a finer (more precise) bowing adjustment of such frame member.
FIG. 22 is a transverse section of a wide caster illustrating the bending of a lower frame member by a remotely actuable fluid cylinder connected to the center of the frame member.
FIG. 23 is a transverse section of a wide caster illustrating the bowing of a structural frame member in the lower carriage using a more compliant member and a remotely actuatable-fluid cylinder connected to the center of the compliant member.
FIG. 24 shows the use of a more compliant member for bending a stiffer member, with two actuatable fluid cylinders located at the respective ends of this compliant member.
FIG. 25 shows the progressive tapering of the downstream portion of casting region by means of a fulcrumed lever driven by a fluid-actuated cylinder for simultaneously bowing a plurality of transverse frame members, each one slightly more than the preceding one.
FIGS. 26 and 27 show two different embodiments of resilient gauge spacers mounted between the side frames of the upper and lower carriages.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to FIG. 1, a continuous casting machine, referred to generally with the reference character 10, has molten metal fed into the upstream end or entry 11 of the machine 10 between upper and lower endless flexible casting belts 12 and 14. The molten metal is solidified in a casting region C (FIG. 3) defined by the spaced parallel surfaces of the upper and lower casting belts 12 and 14.
It is noted that FIGS. 1, 2, 3, 4 and 5 show prior art structures, and it is helpful to the reader to understand these prior structures as background for the present invention.
The casting belts 12 and 14 are supported and driven by means of upper and lower carriage assemblies which are indicated in FIGS. 1, 2 and 3 at U and L, respectively. The carriage assemblies are supported in cantilever relationship from a main frame 23, as seen in FIG. 1. Hence the side of each carriage assembly near this main frame 23 is referred to as being "inboard" while the other side is referred to as "outboard".
The upper carriage U includes two main roll-shaped pulleys 16 and 18 (FIGS. 2 and 5) around which the casting belt 12 is revolved as indicated by the arrows. The pulley 16 near the input end of the machine 10 is referred to as the upstream pulley or nip pulley and the other pulley 18 is called the downstream or tension pulley. Similarly, the lower carriage L includes main upstream (or nip) and downstream roll-like pulleys 20 and 22, respectively, around which the lower casting belt 14 is revolved. In order to drive the casting belts 12 and 14 in unison, the upstream or nip pulleys 16 and 20 of both the upper and lower carriages are jointly driven through universal-coupling-connected drive shafts 24 and 25 by a mechanically synchronized drive 26 driven by an electric motor (not shown).
During the casting operations, the frame 19 (FIG. 1) of the upper carriage assembly U is supported on the frame 21 of the lower carriage assembly L through gauge spacers 17 positioned along the length of the casting region on either side, and the precise thickness of these gauge spacers establishes the mold thickness dimension between the opposed casting faces of the casting belts 12 and 14 and correspondingly the resulting thickness of the cast metal product. Two edge dams 28 (only one of which is seen in FIG. 2) are interposed between the opposed casting faces of the casting belts and are guided. Each edge dam is laterally constrained to establish the cast metal width at the nip or upstream end of the casting machine by an edge dam guide assembly 30.
These two edge dams are driven through frictional contact with the casting belt 12 and 14. The two opposed inner casting faces of these edge dams, together with the two opposed casting faces of the upper and lower casting belts 12 and 14 form four moving casting faces of a moving mold in the casting region C having a generally rectangular cross sectional configuration as seen in FIG. 3. As will be observed in FIG. 2 from the angle "A", the upper and lower carriages U and L are slightly inclined with respect to horizontal so that the casting region C slopes slightly downwardly from the upstream end 11 of the machine 10 to the downstream or exit end 31. Usually the downward inclination "A" is less than 20° from horizontal, and it can be adjusted by means of the jack mechanism 29.
Casting belts 12 and 14 are relatively thin metal belts, for example, of steel which require back-up support and an enormous amount of cooling in order to be able to handle the heat liberated by the solidifying metal in the casting region C. It is desirable to maintain the casting belts 12 and 14 in intimate contact with the cast metal as it solidifies in the casting region, for avoiding air spaces or gaps between the surfaces of the solidifying metal and the casting belts 12 and 14, for reasons as discussed above in the background section. Among the problems is that the metal shrinks as it solidifies. Furthermore, such shrinkage varies somewhat in different areas of the casting region C. The molten metal is initially fed in between the casting belts 12 and 14 from a tundish 32 (FIG. 2) at the upstream end 11 of the casting region C. The molten metal in the downwardly inclined casting region pushes outwardly i.e., upwardly and downwardly, against the belts due to metalostatic "head" pressure. As it continues downstream in the casting region this "head" pressure increases. Even after a thin shell of cast metal forms around the molten core the head continues to increase, pressing this shell forcefully outward. Then, as the shell thickens and the molten core begins to solidify, the head ceases its outward pressure and thereafter shrinkage of the solidifying product becomes progressively greater in the downstream portions of the casting region.
Generally speaking the shrinkage tends to take place away from the upper belt 12, because the weight of the cast product rests upon the lower belt 14. Thus, the conductive transfer of heat from the solidifying metal into the lower belt tends to be more uniform than the transfer of heat into the upper belt in the downstream portions of the casting region. Wherever the upper belt is locally separated from the upper surface of the solidifying product there is no heat transferred by conduction and a radiant or convective heat transfer occurs. Any separation gaps or spaces between areas of the solidifying metal surface being cast and the belts to which coolant is applied creates hot spots ahd nonuniform heat transfer which result in crystallographic degradations, segregations, porosity, and imperfections in the cast product as discussed in the background section above.
As will be seen in FIGS. 2, 4 and 5 the upper and lower belts 12 and 14, respectively, are backed up by a plurality of upper back-up rollers 33 and lower back-up rollers 34, respectively, extending transversely above and below the casting region C. The lower frame 21 in the lower carriage L includes a core section 36 therein, which may be built to be removable as a whole unit. This core section 36 includes a plurality of rigid coolant headers 38 and a frame member 40 by which the lower back-up rollers 34 are supported.
As will best be seen in FIG. 3, the upper carriage U has an upper frame 19 including a similar core section 37 therein which includes a frame member 44 and a plurality of rigid coolant headers 46 which support the upper back-up rollers 33. This core section 37 may be built to be removable as a whole unit.
It is to be understood that these prior art coolant headers 38 and 46 together with their respective frame members 40 and 44 were made as rigid as possible. The coolant headers 38 were each formed with a large rectangular cross sectional shape in the nature of a box beam for resisting significant deflection. The liquid coolant is fed into the rigid headers 38 and 46 through the liquid supply connections 48 and 49. In order to rigidly mount the lower and upper back-up rollers 34 and 33 onto the rigid headers 38 and 46, there are a plurality of laterally spaced longitudinally extending stringers in each carriage in the form of lower L-shaped members 50 and upper L-shaped members 52 secured to the respective headers by brackets 53 (FIG. 4). For further information concerning the structures shown in FIGS. 2, 3, 4 and 5, the reader's attention is invited to U.S. Pat. No. 3,828,841 mentioned in the background section.
The back-up rollers 33 and 34 had solid shafts 43 and 54, respectively, which were either segmented or continuous. When these shafts were segmented, their ends were mounted in bearings rigidly supported on the stringer members 50 and 54 for being as rigid as possible. The inboard and outward ends of the shafts 43 and 54 were mounted in bearing 56 and 58, respectively, so as to be freely rotatable by the moving belts 12 and 14 as they revolved in the carriages. Back-up rollers 33 and 34 have narrow circumferential ridges or fins 55 which are contacted by the upper and lower belts 12 and 14. The cooling fins 55 provide access around the back-up rollers 32 and 34 so that coolant from the headers 38 and 46 may be applied to and maintained travelling rapidly along the reverse surfaces of the casting belts 12 and 14. The headers 38 and 46 have a series of nozzle openings 60 (FIG. 5) along the length thereof and applicator scoops 61 so that liquid coolant is continuously applied to the belts and maintained traveling rapidly along them. By cooling the belts heat is extracted by conduction through the belts from the casting region C which liberates enormous amounts of heat as the molten metal therein cools and solidifies.
In FIG. 5 the casting machine is shown in horizontal position for convenience of illustration, but it is to be understood that the machine actually is inclined downwardly in operation as shown in FIG. 2.
To this point the description of FIGS. 1 through 5 is of conventional structures which have proven to be advantageous over other types of continuous casting methods and machines. In accordance with the present invention a variety of systems are provided for shaping the casting region in a twin-belt casting machine for improving heat transfer and product uniformity and for enhancing machine performance. Among the advantages of such shaping are that the belts will maintain contact with the surfaces of the metal being cast in the casting region in order to provide uninterrupted contact between the belts and the product being cast for providing a predictable heat extraction from the solidifying metal into the belts which is comparable for both the upper and lower belts.
In order to assure maintaining contact of both belts with the solidifying metal as shown in FIGS. 6, 7 and 8, the upper back-up rollers 133 are constructed to be flexible for bowing transversely to the casting region C, while the lower back-up rollers 34 are held rigidly in position. The respective roller shafts 63 and 64 both are hollow. Each upper roller shaft 63 is continuous across the full width of the casting region C and is hollow and is constructed with a predetermined bowability. The lower roll shafts 64 are segmented and have internal segmented shafts 66 FIGS. 7 and 8 which are supported at the ends of each of their segments by the support members 50.
In typical installations of such casting machines the 10 density of the metal or alloy intended to be cast and the intended angle of downstream inclination A are specified. Hence, the "head" or pressure of molten metal against the belts at any given back-up roll location along the length of the casting region C is predictable. Also, the flexibility of a beam of uniform cross section under uniform loading per unit of length (namely, each hollow roller shaft 63) is a function of the fourth power of its free length. Since such uniform loading per unit length against each back-up roller is characteristic of the pressure ("head" ) in the casting region C, the continuous, hollow upper rollers 133 in a wide caster as shown in FIG. 6 are much more flexible (bowable) than the lower rollers 34 which have intermediate supports 50.
Therefore, the end-supported-only upper rollers 133 have predetermined bowability and the loading against them is predetermined. Consequently, the bow which will occur in each upper back-up roller at each position along the length of the casting region is predetermined. In order to compensate for (or offset) the resultant bulge in one surface of the cast product permitted by the flexible back-up system for the belt in one carriage, for example in the upper carriage U as shown in FIG. 6, a convex back-up configuration of a rigidized belt support system in the opposing carriage is provided as shown in FIG. 6. The convex configuration of the rigidized belt back-up system in this opposing carriage, for example in the lower carriage L is predetermined with a convex curvature which will approximately match the predetermined concave curvature of the bowable back-up system. Hence, the cast product will generally be cast to a uniform thickness across its width and will have a slight transverse curvature.
It is to be understood that the transverse curvature shown in FIG. 6 is exaggerated for purposes of illustration. The subsequent rolling operation will remove the slight transverse curvature harmlessly, provided the thickness of the cast product is substantially uniform.
In summary, the compensation for the bulge permitted by the flexible, bowable belt back-up in one carriage is built right into the machine. The desired flexibility and corresponding contoured rigidity may be built into either carriage, but preferably the upper carriage belt back-up is flexible as illustrated in FIG. 6. In other words, I offset and compensate for the lateral bulging permitted by the flexibly constrained back-up support in the, say, the upper carriage by means of rigidly convexly contoured back-up support in the lower carriage. In this system, I retain both mold flexibility and constant product thickness. Such compensation for bulge may be made progressively greater along the direction of casting in the machine, in response to the increasing head of molten metal in that direction and the resulting progressively increasing deflection of the flexible back-up system.
The flexibility of this back-up system will not only prevent the occurrence of gaps or insulating air spaces, but the force exerted by the flexible portion of the back-up system will effectively and controllably maintain belt contact and conductive heat transfer and, moreover, render such heat transfer relatively uniform, with corresponding positive results for the progress of the casting.
The underlying thoughts of this system as described above for FIGS. 6, 7 and 8 may be broadly characterized as "persuasion" rather than attempting coercive domination.
In order to produce the predetermined convex configuration of the lower belt, rigid spacers 62 (FIG. 8) of predetermine thickness are mounted between the rigid headers 38 and the intermediate supports 50 for the segmented rollers 34. As shown in FIG. 8, the adjacent ends of the adjacent sections of the segmented internal shaft 66 are held by the support member 50. One shaft end has a socket 65 which receives the reduced diameter end of the adjacent section of the internal shaft 66. Anti-friction bearings 67 are mounted within the ends of the adjacent sections of the hollow shafts 64 of the lower back-up rollers 34. These bearings 67 are retained against an internal shoulder by means of a spacer sleeve 69 held in place by a retaining snap ring 71, and there is a smaller diameter sleeve 73 providing a space 75 for holding grease. A cut-out space 76 in the support 50 permits the socket end of the section of the internal shaft 66 to be removed from the support 50, and similarly in other supports 50 so that the segmented shafts 34 can be individually removed from the carriage and replaced, if desired.
It is to be noted in FIGS. 6 and 7, that there are fixed stub shafts 70 mounted in sockets in the frames 19 and 21, and the bearings 59 at the ends of the back-up rollers 133 and 34 are self-aligning bearings for permitting free rotation of each roller even though its axis is deflected out of alignment with the axis of the stub shaft 70.
It is to be noted, that in view of the bowability of the back-up rollers being a fourth power function of their unsupported length, in the case of a wide casting region C as shown in FIG. 6 the bowability of the end-supported-only, one-piece flexible roller 133 may be greater than the predetermined spring constant value desired, particularly at locations downstream in the machine where the metal "head" pressure is greater. It is not feasible to attempt to decrease their bowability (i.e. increase their spring constant) by increasing their hollow shaft 63 diameter beyond a modest amount, because these back-up rollers are intended to be closely spaced longitudinally along the casting region for appropriately supporting the belt. Too large a shaft diameter would interfere with close roller spacing.
Consequently, for wide casting regions C in order to limit the effective bowability (i.e. to increase the effective spring constant of the rollers 133) external means 98, 100 (FIG. 9) may be employed. For the purpose of thus modifying roller flexibility, rolling external back-up bearings 98,100 for each said flexible back-up roller 133 may be placed close to the roller shaft 63 and external to it, said bearings being able to roll against said shaft 63 in the manner of a roller wheel, one per location (see FIG. 9).
Yet this external flexibility modification is not intended for sharply limiting the elastic bending of back-up rollers, since any absolute rigidity in the back-up system may cause damage by the passage of stray, prematurely frozen metal. I prefer to mount said external back up roller bearing 98 resiliently, in order that they may themselv flex away from the casting region. Thus, the roller wheel 98 is mounted in a bracket 99 which in turn is seated upon a resilient mounting member 100 on the rigid header 46. This resilient mounting 100 is formed of ribbed or castellated rubber for providing the desired amount of compliance. Such resilient mounting 100 somewhat reduces or snubs the flexing for providing the desired amount of compliance. Such resilient mounting 100 somewhat reduces or snubs the flexing excursion of the back-up rollers 133 to a predetermined amount. The resilience of such mounting 100 may be obtained by means of grooves or castellated and bonded rubber sandwich pads, or by Belleville conical spring washers mounted on the mounting bolts for the bracket 99. The external rolling back-up wheels 98 so mounted may or may not touch the shafts 63 of the respective back-up rollers 133 when the machine is empty, depending on the particular application and the downstream position of the particular back-up roller 133.
If desired, in order to mitigate slightly the rigidity of the opposing convexly bowed rigid back-up rollers 34, slightly compliant spacers 101 may be mounted between the support members 50 and the rigid lower headers 38.
In order to assure that the positions of the rigid, convexly bowed back-up rollers 34 are accurately predetermined relative to the casting region C, the lower carriage frame 21 and the lower headers 38 and longitudinal stringer members 50 are constructed to be as rigid as practicable.
So far there has been described systems which involve predetermination of the desired bowability. Now there will be described systems which are adjustable at will, even being adjustable while the casting machine 10 is running.
SYSTEMS FOR SHAPING THE CASTING REGION PROVIDING ADJUSTABILITY
In order to elastically bend the flexible, bowable back-up rollers 133 for supplying adjustable forces toward the casting belts and hence toward the casting region C, approximately equal and opposite couple-forces are applied to non-rotating, lever-like, stub-shaft extensions 68 of the bowable back-up rollers 133 as shown in FIGS. 10 through 15 and 17 through 19.
As shown in FIG. 12A, the bowable back-up rollers 133 are connected to the stub-shaft extensions 68 by a pair of axially spaced anti-friction bearings 67 located in a bearing assembly 77 located within a large end portion 79 of the roller 133. The two bearings 67 are axially separated by a spacer sleeve 83 and are mounted upon an inner sleeve 85 on the stub-shaft extensions 68. The space between these sleeves 83 and 85 may be used to hold grease for the two bearings 67.
In order to provide an effective pivot point (i.e. a fulcrum) for the lever-like stub-shaft 68, there is a hardened steel collar or housing 72 seated in a drill hole in the respective carriage frame 19 (or 21 as the case may be) held by a set screw 74 and having an internal shoulder 86 which acts as a fulcrum for the stub-shaft lever 68. Therefore, adjustably moving the outer end of the stub-shaft lever 68 applies a couple-force (i.e. a bending moment) to the flexible back-up roller 133 for bowing it as desired. Although the fulcrum is actually located at 68, the effective pivot point may be considered to be located at 86A on the axis of the stub-shaft lever.
An approximately equal and opposite-sense couple-force (bending moment) is also applied to the opposite end of the flexible roller. By virtue of the couple-forces (bending moments) applied by the levers 68 to the ends of bowable roller 133 a constant moment is applied throughout the length of the roller; that is, if this roller 133 were otherwise free, its axis would be bowed into a circular arc. The stub shafts may alternatively be extended into shafts passing all the way through the roller, as shown in FIGS. 10 and 11.
As shown in FIG. 10 the stub-shaft levers 68 for the upper bowable back-up rollers 133 have actuating levers 78 connected to their outer ends. Each such actuating lever 78 is driven by adjustable means 80 shown as a horizontally positioned tightening machine screw which screws into a socket in the side of the machine frame 19. The stub-shaft lever 68 has a fulcrum 86 provided by a collar or housing 72.
The lower back-up rollers 134 are bowable, having self-aligning bearings 59 and fixed stub shafts 70. In the downstream portion of the casting region C where the metal in the casting region C is mostly all solidified, the flexible back-up rollers 134 conform to the thickness of the cast product. Therefore, the adjustment of the adjusting means 80 will tend to establish the arc of transverse curvature of the casting region C and will cause both belts 12 and 14 to hug the product for achieving good and uniform heat transfer over the areas of both top and bottom surfaces of the solidifying product.
In the upstream and central portions of the casting region C, where more of the metal is still molten, the "head" of the molten metal will cause predeterminable bending of the lower flexible rollers 134. The back-up-roller-bowing adjustment means 80 therefore are initially adjusted to provide a bow in each successive upper roller 133 which will correspond with the predetermined anticipated bow of the opposed lower roller 134. During operation of the casting machine the operator may then further adjust the adjusting means 80 if desired for further modifying the shape of the casting region C at the location of each adjustable back-up roller 133.
In the upstream and central portions of the casting region C the bowing of the adjustable roller 133 may,if desired, be made slightly less than the anticipated predetermined bowing of the lower rollers 134 for providing a transverse contour of the casting region C which is very slightly thicker near the middle as compared with the thickness of the margins near each edge dam 28. This slightly thicker middle then compensates for subsequent shrinkage of the middle of the cast product as it solidifies and cools below its freezing temperature.
The back-up roller bowing method and system of FIG. 11 is similar to that shown by FIG. 10, except that the fulcrum 86 is formed by the juncture of a conically tapered outer section of the stub-shaft lever 68 and a cylindrical inner section of this stub-shaft lever. Consequently, the hardened steel housing or collar 72 does not include an inner shoulder, and this housing or collar is extended out beyond the side of the frame 19. The adjusting means 81 is a vertically extending machine screw whose shank extends down through a hole in the wall of the cylindrical collar or housing 72. This adjusting screw 81 screws into a threaded hole in the outer end of the conical outer section of the stub-shaft lever 68. Thus, by tightening up on the two adjusting screws 81, the axis of the bowable back-up roll 133 is bowed convexly down toward the casting region C.
The back-up roller bowing system of FIGS. 12 and 12A is similar to that of FIG. 11, except that the adjusting means 82 is a longer screw than the screw 81, so that compliance means 84 is included in the adjustment. This compliance 84 is provided by a compression spring which surrounds the screw shank and is compressed between a washer beneath the head of screw 82 and a washer seated on the wall of the cylindrical housing or collar 72. The threaded lower end of the screw shank screws into a threaded hole in the outer end of the conical outer portion of the stub shaft lever 68. Among the advantages of including this compliance 84 which modifies the adjustment effect of the screw 82 are those resulting from the fact that a smaller gradiant of adjustment is afforded than with the direct (non-compliant) adjustment means shown in FIGS. 10 and 11. In other words, with the same screw thread pitch, a given amount of turning of the screw 82 will cause less bowing of the axis of the roller 133 than with the screws 81 or 80. The compliance of the springs 84 is predetermined to have a range comparable with the bowing compliance of the roller 133 as coupled through (reflected through) the stub-shaft levers 68 to the respective springs 84. At locations along the casting region where proportionately more bowing of the rollers 133 is desired, somewhat stiffer springs 84 may be employed.
Another advantage of using these compliant means 84 is that they will allow the casting belt 12 to deflect or yield for avoiding damage in case a prematurely solidified chunk of metal passes through the casting region C having a size greater than the spacing between the belts 12 and 14.
In FIG. 12 the fulcrum 86 is provided by the conical/cylindrical junction on the stub-shaft lever 68. In FIG. 12A this fulcrum 86 is provided by an internal shoulder in the collar or housing 72, as previously described. If desired, as shown in FIG. 12A, the threaded lower end of the shank of the screw 82 is extended down through a second hole in the wall of the housing or collar 72, so that an adjustable lock nut 88 may be used to prevent inadvertent "creep" of the adjusted position of the adjusting screw 82.
As shown in FIG. 13, in order to provide remote control of the adjustment of the back-up roller bowing, there are fluid-actuated cylinder and piston units 90 whose piston rods 91 are pivotally connected to the respective outer ends of the stub-shaft levers 68. There are a pair of pipe lines 92 for fluid, connected to the upper and lower ends of the cylinder units 90 for operating the piston therein. Preferably these units 90 are hydraulic units; however, pneumatic cylinder and piston units 90 may be used, if desired.
The use of pneumatic units will inherently provide compliance by virtue of the compressibility of the compressed air in the cylinder 90. In order to provide compliance in the remote control system when hydraulic liquid is used as the actuating fluid, check valves are omitted from the pressure regulating valves, which are set at the desired pressure in the cylinder and piston units 90 corresponding to the predetermined desired bowing of the back-up rollers 133.
Actuation of these units 90 pulls upwardly on the piston rods 91, thereby controllably bowing the axis of the roller 133 convexly down toward the casting region C. A remote control console (not shown) is located near the operator's station including display meters providing a read-out of the pressure in the control units 90 for each bowable back-up roller. The console display meters may also be calibrated in thousandths of an inch or hundredths of a millimeter for indicating the controlled bowing of the mid-point of the axis of each roller 133 away from a straight line. In other words, the pressure in each successive pair of units 90 for each successive bowable roller 133 along the casting region C can be independently controlled, and the resultant amount of deflection of each roller can be read on the read-out displays of the console.
The system for adjustably bowing the back-up rollers 133, as shown in FIG. 14, is similar to that shown in FIGS. 12 and 12A in that compliance springs 84 are associated with the adjustment screws 82 for bowing the flexible back-up rollers 133. The lower back-up rollers 34 are of rigid three-section construction with longitudinal stringer support members 50 mounted on rigid transverse frame members 38, for example, which may be the coolant headers as explained above. The upper back-up rollers 133 are being bowed convexly toward the casting region C.
In order to cause the axis of the bowed rollers 133 to have a flatter (longer radius) arcuate curvature opposite the middle of the casting region C for causing the upper belt 12 to hug the solidifying metal opposite the rigidly backed-up belt 14 which has a straight transverse shape, the diameter of the middle shaft portion 96 of the hollow bowable roll shaft is made larger than the end shaft portions 94. The diameter of the bore of this hollow roller 133 is uniform. Therefore, the wall thickness of the middle shaft portion 96 is proportionately increased more than the difference in the outside diameter of the middle shaft portion 96 as compared with the outside diameter of the end shaft portions 94. (It is noted that the stiffness of a length of round solid shaft in bendingvaries as the fourth power of its diameter.) Consequently, the stiffness of the hollow middle portion 96 in bending varies as a higher power function of its outside diameter than in the case of a solid shaft. As a result, relatively small increases in outside diameter of the middle portion 96 of this hollow shaft will provide relatively large increases in stiffness as compared with the hollow end portions 94.
It is to be understood that the differences in diameter at 96 and 94, as shown in this FIGURE and in FIG. 15, are exaggerated for purposes of illustration, and the bowing of the roller 133 is also exaggerated. The solidifying product in the casting region C is shown in FIGS. 14 and 15 as having shrunk slightly relative to the height of the edge dams 28. (Not only is the cast product cooling and shrinking, but the solid metal blocks in the edge dam 28 are becoming heated and are expanding.) This shrinkage relative to the expanding edge dams 28 is indicated exaggerated at the upper surface of the margins of the cast product at 97. The objective of the more flexible end shaft portions 94 is to bow the back-up roller 133 downwardly for causing the upper belt 12 to hug the shrinking cast product as close to the edge dams 28 as possible.
The system for bowing the back-up rollers 133 in FIG. 15 is similar to that described above in FIG. 14, except that remotely controllable fluid-actuated cylinder and piston units 90 are employed, thereby providing similar operating and control advantages as explained in connection with FIG. 13.
In FIG. 16 the casting regions shown selectively tapered toward the downstream or exit end 31. The casting region is labelled "C or CB" for indicating that this casting region may be relatively wide as illustrated in FIGS. 6, 9-15, 17, 20-24 or may be relatively narrower and higher for casting a bar product as illustrated in FIGS. 18 and 19. The molten (liquid) metal is indicated dotted at 125, and the solidified (frozen) metal is indicated by diagonal cross-hatching lines at 135. The cast product P travels away from the caster exit 31 carried by appropriate conveyor means (not shown), and secondary cooling means (not shown) are often employed for further cooling of the cast product P as immediately as possible after exiting from the caster.
It is to be noted that the molten interior region 125 of the solidifying product 135 continues downstream along a considerable distance approaching toward or even extending beyond the exit 31. This molten interior 125 may be called the molten or "liquid core" or "liquid sump". Generally speaking, for a given thickness of cast product P, the faster the caster 10 is running, the further downstream extends the interior liquid sump 125. In practically every case where the liquid sump 125 extends downstream beyond the exit 31 secondary cooling is employed.
The casting region C or CB is shown longitudinally divided into an upstream portion or zone 102, a central portion or zone 104, and a downstream portion or zone 106. In this upstream portion or zone 102, the rigid back-up rollers 34 and the flexible back-up rollers 133 hold the casting belts 12 and 14 generally parallel. In this upstream portion 102, very slight excess (or bulging) in thickness (as seen in transverse section) may be provided in the major central transverse area of the casting region C or CB (i.e. the transverse contour of the casting region C or CB may be very slightly thicker over the major central portion of its area) as compared with the margins, because the margins of the cast metal 135 adjacent to the edge dams tend to solidify and cool more quickly than the major central area of the cast metal for thereby compensating for the subsequent shrinkage in this major central area (as seen in transverse section).
In the longitudinal central portion or zone 104 of the casting region C or CB the belts 12 and 14 begin to converge slightly downstream, i.e. the mold space is tapered by the rigid back-up rollers 34 or flexible lower back-up rollers 134 or 108 (FIG. 18) in cooperative action in opposition to the flexible upper rollers 133 or 107 (FIG. 18).
The flexible back-up rollers may be bowed, adjusted and controlled in their belt contour configuration in the respective zones 102, 104 and 106 by any one or more (singly or jointly) of the various systems as described above, or as described hereinafter. The longitudinal taper through the various zones 102, 104, 106 may be varied and may be utilized for achieving various transverse contours as desired for causing both belts to hug the solidifying metal 135 and for producing a cast product P of the desired dimensions and desired uniform metallurgical properties.
In the longitudinal downstream portion or zone 106 of the casting region C or CB, the belts 12 and 14 converge with an increased taper as compared with the zone 104 as achieved by the rigid lower rollers 34 or flexible lower rollers 134 or 108 (FIG. 18) in cooperative action in opposition to the flexible upper rollers 133 or 107 (FIG. 18).
The "head" pressure effect against the belts may be greatest in the zone 104 or in the zone 106 depending upon such factors as the amount of solidified metal 135 as compared with liquid sump 125, speed of the caster 10, density (weight per unit volume) of the molten metal 125, overall thickness of the product P.
If desired, the downstream taper of the longitudinal zones 104 and 106 may be accomplished in part by causing the upper carriage U to converge downstream slightly toward the lower carriage by using compliant gauge spacers 121 (FIG. 26) or 128 (FIG. 27) between the side members of the carriage frames 19 and 21 near the exit end 31 in lieu of the rigid gauge spacers 17 (FIG. 1). Thus, rigid gauge spacers 17 are used near the upstream end 11 and compliant ones 121 or 128 (FIGS. 26 or 27) are used near the downstream end 31. Therefore, the downstream end of the upper carriage U may be caused to "float" somewhat upon the "head" pressure of the liquid sump 125 acting against the area of the upper belt.
In FIG. 17 the remotely controllable fluid-actuated cylinder and piston units 90A are connected between the stub-shaft levers 68 for applying essentially equal and opposite forcecouples (bending moments) to the respective opposed bowable lower and upper rollers 134 and 133. The piston rods 91 are detachably pivotally connected to the respective lower stub-shaft levers 68.
The circumferential ridges or fins 55 are shown more closely spaced at 55A (FIG. 17) near the margins of the casting region C, thereby providing the operator with the option of positioning the edge dams 28 closer together. It is desired that the fins 55A be relatively close together for firm back-up of the respective belts where the edge dams are located.
In the modification shown in FIG. 17A, the closely spaced fins 55B opposite the edge dams 28 have a reduced diameter as compared with the other fins 55 on the same back-up rollers opposite the casting region C. These reduced diameter fins 55B allow the larger fins 55 to push the respective belts 12 and 14 inwardly for causing the belts to hug the solidifying shrinking metal at the margins 97 as close to the edge dams as possible.
This reduced diameter fin modification of FIG. 17A can be used to advantage in the zone 106 (FIG. 16) and may be used in the zone 104 (FIG. 16) if desired. This reduced diameter fin modification can be used to advantage in conjunction with the increased flexibility of roller end sections 94 (FIGS. 14 and 15).
FIGS. 18 and 19 show the casting of a bar product and so the casting region is labeled "CB". The internal liquid sump 125 is shown, and this liquid sump is smaller in FIG. 19, because FIG. 19 is a section taken farther downstream than FIG. 18. The edge dams 28 are shown higher than in previous FIGURES, because a bar product is cast relatively thicker.
In order to compensate for the shrinkage 97 of the solidified metal (FIG. 19) the large end portions 79A (FIG. 19) of the upper and lower bowable back-up rollers 107 and 108 are made smaller in diameter than the normal-sized fins 55. (These large end portions 79A may include one or more grooves 123 for allowing coolant to flow along the belt.) The resulting belt clearance spaces at the edge dams permit the fins 55 to deflect the belts slightly to hug the shrinking product very effectively for minimizing any shrinkage gap 97 at the margins adjacent to the edge dams 28. Indeed, such reduced diameter techniques of relief effectively permit roller-bending or taper to be used downstream.
In FIG. 18 the large end portions 79 are shown to have the same diameter as the fins 55.
For providing the fulcrums 86, the shaft housings 72 project inwardly from the side members of the respective carriage frames 19 and 21 and include internal shoulders formed by hardened steel ring inserts.
The remotely controllable fluid-actuated cylinder and piston units 90B for bowing the rollers 107 and 108 are pairs of cylinders located on opposite sides of the lower stub-shaft levers 68. In other words, this pair of cylinders straddles the lever 68. These pairs of cylinders are mechanically interconnected by a yoke structure 127 having a hardened steel ring insert 129 forming the outer pivot fulcrum for the lower stub-shaft lever 68. The pairs of piston rods 91 are also interconnected by a yoke structure 137 having a similar ring insert forming the outer pivot fulcrum for the upper stub-shaft lever 68. The advantage of straddling the stub-shaft lever 68 is that longer cylinder units 90B can be employed more conveniently for a greater range of cast thicknesses. The advantage of the modified design with its greater leverage and heavier parts is that it permits more effective roller-bending for narrow cast products. Equal and essentially opposite force-couples (bending moments) are advantageously being applied to both the upper and lower rollers 107 and 108 for achieving symmetrical upper and lower belt contours.
In the embodiments described above, the belt shape and contact control has been primarily accomplished by directly bowing flexible back up rollers 133, 134, 107, 108 in various ways. Another system which is shown in FIG. 20 involves the elastic bending ing of a relatively rigid structural frame member 112 having relatively rigid back-up rollers 33 mounted thereto by the stringer members 52, so that these segmented rollers 33 also will be caused to assume an overall arcuate configuration.
In FIG. 20, the transverse frame member 112, which for example may be a header or other frame member, is stiffly bowable. It has upstanding arms 116 at either end. A transverse rod 120 is mounted in the frame 19 of the upper carriage U having tightening nuts 115 on threaded end regions of this rod. In this embodiment by tightening the nuts 115, the frame member 112 is bowed and since the back-up rollers 33 are slaved to this frame member, the back-up rollers also bow a corresponding amount. The lower back-up rollers 134 are bowable under the pressure of the metal "head".
In FIG. 21, which is similar to FIG. 20, a transverse member is positioned generally parallel with the stiffly flexible frame member 112. This second member 110 is more flexible than the first member 112, for example, it is a bowable leaf spring member. This second member 110 is attached by bolts 119 to the ends of the first member 112 with a center spacer or block 114 positioned therebetween. By tightening the bolts 119 at the ends of the bowable leaf spring member, the first member 112 is bowed as is the segmented upper back-up roller 63 which is rigidly attached to the latter by the stringer members 52. By utilizing this second member 110, which has more flexibility than the first member 112, a finer, more determinate, vernier bowing adjustment can be made of the transverse frame member 112 and hence more determinate bowing of the configuration of the back-up roller 33.
In FIG. 22 a remotely controllable fluid-actuated cylinder and piston unit 117 is pivotally connected at 139 to a bracket 109 mounted centrally on a lower stiffly flexible transverse frame member 112, for example, which may or may not be a coolant header. Thus, a remotely controllable bending moment is applied for bowing this transverse frame member 112 whose ends are captured by flanges at 113 and retainers 141 bolted to the lower frame 21. Accordingly, as the member 112 is bowed, the segmented rigidly mounted back-up roller 34 is correspondingly bowed to urge the lower belt 14 against the cast metal. The upper back-up roller 133 is bowable, so that the upper belt 12 stays in contact with the top surface of the cast metal.
In the embodiment illustrated in FIG. 23 a combination of the transverse frame bowing methods and systems utilized in FIGS. 21 and 22 is employed. Accordingly, the upper back-up roller 133 is bowable. The lower segmented back-up roller 34 which is rigidly mounted to the lower frame member 112 is also bowed by actuating the centrally located cylinder unit 117 which is secured by mounting means 143, for example bolts, upon a second, generally parallel, more flexible transverse member 110, for example, a leaf spring member, whose ends are also captured by the retainers 141. In effect, the remotely controllable unit 117 is drawing a bow by pushing up on the stiffly flexible member 112 while pulling down upon the relatively more flexible second member 110. Therefore, the remotely controllable unit 117 in FIG. 23 provides an accurately determinate bowing of the first frame member 112 for precisely controlling the configuration of the roller 34 which is rigidly slaved to the member 112.
FIG. 24 shows a system for controllably bowing rollers 34 generally similar to FIG. 23, except that a pair of remotely-controllable fluid-actuated units 118 mounted on the lower carriage frame 21 are pivotally connected at 111 to the respective ends of the second member 110. A spacer block 114 is located between the central regions of the first and second members 112 and 110, respectively.
In order to simultaneously bow a plurality of transverse frame members 140, for example, headers, there is a longitudinally positioned rocker arm 136 whose upstream end is effectively pivoted at 142 by a fulcrum connection to the frame 19 of the upper carriage U. A remotely controllable fluid-actuated cylinder and piston unit 138 is secured to the frame 19 in the vicinity of the downstream end of this rocker arm 136. The rocker arm 136 and the cylinder unit 138 are located midway between the inboard and outboard sides of the upper carriage U. Its piston rod 91 urges the downstream end of this rocker arm 136 for bowing the transverse frame members 140 convex down toward the casting region for producing a corresponding convex down configuration of the upper back-up rollers 33 which are slaved to the respective transverse frame members 140. The opposed lower back-up rollers 134 are bowable.
Each successive transverse frame member 140 is bowed slightly more than its upstream member, because each successive frame member 140 is being acted upon by the rocker arm 136 further downstream from its pivot fulcrum. Thus, a remotely controllable taper of the casting region C is advantageously provided by actuating the unit 138 acting through the rocker arm 136.
The compliant gauge spacer 121 (FIG. 26) includes a head 122, a locating pin 124 which engages in a socket 144 in the side frame member of the lower carriage 21. This locating pin 124 is screwed into the head 122 with a plurality of Belleville washers (conical spring washers) 126 on the shank of this pin. These spring washers are captured by a shoulder 146 on the locating pin 124. The lower surface of the head 122 has a concave conical shape 148 with a pitch or slope which is more shallow than the pitch or slope of these spring washers when they are in their unloaded (relaxed) condition, and thus there is a gap 131 for permitting compliant deflection of these spring washers up to a limit when this gap 131 is closed. Hence, the slope of concave surface 148 acts as a stop for limiting the deflection of these spring washers to a predetermined limit.
The compliant gauge spacer 128 (FIG. 27) has a head 122 and a locating pin 124 inserted into a socket 144. The locating pin 124 is fastened by a small diameter stud 130 passing through a small diameter hole 150. A stiffly flexible leaf spring 152 is thereby captured on the stud 130. The deflection of this leaf spring 152 is limited by the gap at 132. A retainer pin 154 seated in a socket in the side frame 21 engages in a notch 156 for holding this leaf spring in longitudinal alignment with this side frame.
It is to be noted that the bearing assemblies 77 (FIG. 12A) can be inverted (turned inside out) by using hollow cylindrical stub shafts which encircle the bearings 67 which, in turn, encircle the end of the roller shaft 63.
Also, it is to be noted that in FIGS. 6, 8 and 9, the transverse members 38 and 46 can be other members than headers.
Since other changes and modifications, varied to fit particular operating and casting requirements and environments, will be understood by those skilled in the art, the invention is not considered limited to the examples chosen for purposes of illustration, and its scope includes all changes and modifications which do not constitute a departure from the true spirit and scope of this invention as claimed in the following claims and reasonable equivalents to the claimed elements. | Systems are provided for continuously casting metal product directly from molten metal confined and solidified in a casting region defined by upper and lower, cooled, endless, flexible, traveling, casting belts supported by belt support systems including back-up rollers in respective upper and lower carriages and laterally defined by first and second traveling side dams. The back-up rollers and belt support systems shape and maintain the casting region for improved heat transfer between cast metal and belts for improved product uniformity and enhanced machine performance. Several systems are disclosed including having one belt flexibly constrained, resulting in a transverse bowing away from the casting centerline due to liquid metal head, with the opposing belt being rigidly constrained and contoured or transverselybowed towards the casting centerline in a configuration that compensates for displacement of the flexibly constrained belt resulting in a uniform transverse cross section. Systems are disclosed including bowing the upper back-up rollers down either by manual adjustment or remote control and at the same time allowing the lower rollers to yield; intentionally rigidizing the upper and/or lower back-up rollers or sections thereof; bowing both sets of back-up roller in equal and opposite directions, bowing the rollers inward or outward using either manual adjustment or remote control tensioning; bending structural frame members which are in support relationship with rollers, thus maintaining predetermined configurations of rollers in contact with the belts and further including downstream tapering of the casting region. | 1 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims the benefit of U.S. Provisional Patent Application No. 61/278,880 filed Oct. 13, 2010, which is incorporated herein by reference in its entirety.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
Not applicable.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a method of synthesizing a tetradentate amido macrocyclic ligand and its metal complex.
2. Brief Description of the Related Art
Macrocyclic ligands with various donor atoms are very important to stabilize metals with high valent oxidation states. Such macrocyclic complexes play a significant role in mimicking either structure and/or functions of several metallo enzymes, especially enzymes which use hydrogen peroxides or oxygen for their activity. Amongst many, the development of oxidation resistant stable tetraamido macrocyclic ligand (TAML) developed by Collins and co-workers has drawn much attention in the last two decades or more.
Various metal complexes with unusually high oxidation states using TAMLs have been frequently reported previously by Collins et al. Interestingly, iron complexes of TAMLs (Fe-TAMLs) posses a unique property of activating either hydrogen peroxide or oxygen and act as green oxidation catalysts. Using Fe-TAML and hydrogen peroxide in water, several oxidation chemistries have been demonstrated starting from pollutants remediation associated with the textile, pulp and paper, and pesticides industries to rapidly killing anthrax-like spores and removing sulfur from hydrocarbon fuels. In order to synthesize TAMLs, several synthetic routes have been reported with varying success. In one such instance to synthesize the macrocyclic ligands uses of inorganic or organic azides were encountered, which is not desirable in terms of safety. Coupling of an aromatic diamine and a diacid derivative in a two step process has been utilized; however, yield of ligands using this method is very low.
In recent years an improved synthetic method TAML ligand has been reported. The method uses synthesis of phthalic acid protected amino acid derivatives and then subsequently macrocycle synthesis using several steps. Uffelman and co-workers developed a new synthetic method of making acid chloride of amino acids using phosphorous pentachloride in presence of and reacting with the aromatic amines. Even though over the years easier methods have been developed, synthesis of such macrocyclic ligands needs a much simpler approach.
Several tons of hydrogen peroxide (H 2 O 2 ) are annually used for stoichiometric oxidation purposes. The activity of H 2 O 2 can be enhanced by using various metal complexes. However, the major challenge is to find suitable metal complexes, which can withstand both oxidative stress and also attain high valent metal oxidation states for activity. In this context, a major research effort has evolved over the years focused on the development of metal complexes which mimic structures and/or functions of H 2 O 2 or oxygen activating metallo-enzymes. Ligands that possess various donor atoms and geometries are very important in order to achieve suitable H 2 O 2 activating metal complexes or catalysts.
Examples of metal ligand containing bleaching compositions are found in U.S. Pat. Nos. 6,241,779; 6,136,223; 6,099,586; 5,876,625 and 5,853,428, the disclosures of which are incorporated herein be reference. An example of a long-lived homogenous amide containing macrocyclic compounds is found in U.S. Pat. No. 6,054,580, the disclosure of which is incorporated herein by reference.
BRIEF SUMMARY OF INVENTION
To achieve the above objectives, the present invention is directed to a new method of synthesis for a tetradentate amido macrocyclic ligand and its metal complex, resulting in much higher yields. Further, the newly synthesized Fe-complex has been tested as an activator of H 2 O 2 and found to be very efficient in performing various oxidation chemistries.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
FIG. 1 is the molecular structure of tetradentate amidomacrocyclic ligand and its Fe-complex.
FIG. 2 is the reaction scheme leading to the production of tetradentate amidomacrocyclic ligand.
FIG. 3 is the electro spray ionization mass spectrum (ESI-MS) of Fe-Complex (negative ion mode) and its theoretical isotope distribution (inset).
FIG. 4 is a graphical depiction of the change of absorbance as a function of time and wavelength.
FIG. 5 is a table listing the dyes that were bleached and the time of bleaching at pH 10 and ph 11.5.
FIG. 6 shows the molecular reaction of oxidation of a tertiary amine to its corresponding N-oxide.
FIG. 7 is a chart listing the turn over numbers and percent yield for pyridine, triethylamine, and 4-dimenthylaminopyridine synthesis.
DETAILED DESCRIPTION OF THE INVENTION
With reference to FIGS. 1-7 , the new methodology of synthesizing tetradentate amide based macrocyclic ligand and its iron complex can be described. The molecular structure of tetradentate amide based macrocyclic ligand 1 and its iron complex 2 are shown in FIG. 1 . Tetradentate amide based macrocyclic ligand 1 was synthesized using standard reactions of amine and acid chlorides with high yield. Ligand 1 was used to develop its iron complex 2 , which is soluble and stable in aqueous solution. Iron complex 2 activates H 2 O 2 in water under ambient conditions and acts as an excellent oxidation catalyst.
A new tetradentate amide based macrocyclic ligand 1 and its Fe-complex 2 are synthesized according to FIG. 2 . More specifically, O-phenylenediamine (3 gm, 27.8 mmol) and triethylamine (27.8 mmol, 3.8 mL) were dissolved in 47 mL of dry THF (dried over sodium and benzophenone). Di-tert-butyl-carbonate (6.05 gm, 27.8 mmol) was dissolved in 50 mL of THF. Both the solutions were combined in two gas tight syringes separately and added in a three neck round bottom flask containing 50 mL THF via a syringe pump at 0° C. The addition was completed within 16 hours. The reaction mixture was then further stirred at room temperature for another 4 hours. After the reaction, solvent was removed using a rotoevaporator. The residue was dissolved in 200 mL dichloromethane and washed with 5% Na 2 CO 3 (3×100 mL). The organic layer was collected and dried using anhydrous sodium sulfate. After filtration, the organic layer was concentrated using a rotoevaporator to yield the slightly yellow product 3 . The compound was further purified by recrystallizing from benzene. Initially one of the amine groups of O-phenylenediamine was protected with a tert-butyloxycarbonyl (BOC) group to obtain (2-Amino-phenyl)-carbamic acid tert-butyl ester 3 . The stability of the BOC group under basic conditions and its easy removal by acids is of primary advantage for synthesizing the ligand following this method.
Compound 4 was synthesized through a reaction involving (2-Amino-phenyl)-carbamic acid tert-butyl ester 3 . More specifically, (2-Amino-phenyl)-carbamic acid tert-butyl ester 3 (2.08 gm, 10 mmol,) was dissolved in 50 mL dry THF. To this solution was added triethylamine (1.4 mL, 10 mmol). The mixture was transferred to a 100 mL two neck round bottom flask and cooled to 0° C. Dimethylmalonyl chloride (1.45 mL, 11 mmol) dissolved in 50 mL dry THF was added into a dropping funnel and the solution was combined slowly for 60 minutes to the other solution drop-wise under nitrogen atmosphere. During the addition, a white precipitate was noted to be formed. The free amine group of (2-Amino-phenyl)-carbamic acid tert-butyl ester 3 reacts with both acid chlorides of dimethylmalonyl chloride to produce compound 4 . The reaction proceeds very rapidly in the presence of a triethylamine. Low temperature was maintained since the reaction is an exothermic reaction. After addition of dimethylmalonyl chloride, the reaction mixture was brought to room temperature and stirred overnight under inert atmosphere. After the reaction, the solution was filtered to remove insolubles and filtrate was collected. The residue was dissolved in 200 mL dichloromethane and washed with 5% Na 2 CO 3 (3×100 mL). The organic layer was collected and dried using anhydrous sodium sulfate. After filtration, the organic layer was concentrated using a rotoevaporator to yield an off-white crude product, compound 4 . Following evaporation of the solvent, the product was washed with diethyl ether and dried in vacuum. The compound 4 was further purified by recrystallizing from benzene.
In the next step, the BOC protecting group was removed by treating with trifluoroacetic acid, which occurs within minutes. Compound 4 (1.5 gm, 3.18 mmol) was dissolved in 10 mL dichloromethane and cooled to 0° C. To this solution was added a mixture of trifluoroacetic acid (10 mL) and dichloromethane (20 mL) drop-wise over a period of 30 min under inert atmosphere. After the addition, the reaction mixture was brought to room temperature and stirred for another 2 hours. The reaction mixture then was concentrated using a rotoevaporator to obtain a slightly yellow viscous liquid. This solution was diluted with 75 mL of water and the pH was adjusted with enough 1 M sodium hydroxide solution to bring the pH of the solution to 10 and then extracted with 20 mL of dichloromethane (3×20 mL). The organic layer was dried using anhydrous sodium sulfate. After filtration, the organic layer was concentrated using rotevaporator to yield the white product of compound 5 .
For the synthesis of 3 , 4 and 5 , either washing with dilute mineral acid and/or bases or simple recrystallization from benezene was performed to purify the product with no column chromatography required. Compound 5 (0.408 g, 1.31 mmol) was dissolved in 30 mL dry THF and to the solution was added triethylamine (0.38 mL). The solution was collected in a gas tight syringe. Oxalyl chloride (0.11 mL, 1.31 mmol) was dissolved in 30 mL dry THF and collected in another gas tight syringe. Both solutions were added drop-wise via syringe pump, into a round bottom flask containing 30 mL dry THF that had been cooled to 0° C. and maintained under inert atmosphere. The addition was completed in 16 hours. The mixture was allowed to continue stirring for an additional 4 hours at room temperature. Finally, ligand 1 was synthesized by adding separate solutions of oxalyl chloride and compound 5 in tetrahydrofuran very slowly using a syringe pump. This process is required to reduce other side reactions and maximize macrocycle production. In fact, the structure of 5 may be helpful to some extent in keeping the two amine groups close together which can easily react with oxalyl chloride to form the macrocycle. During the reaction the macrocycle precipitates out from the solution and can be recovered just by simple filtrations. Washing with water was necessary to remove any triethylamine hydrochloride salt which co-precipitates with the ligand during reaction. The resulting product was transferred to a round bottom flask and 200 mL of diethyl ether added. The mixture was sonicated for 15 minutes and then filtered. The precipitate was collected and rinsed with additional ether to further purify the material. The resulting product was dried for 12 hours under vacuum at 80° C. to yield the desired macrocyclic ligand 1 . The 1 H-NMR spectra for all the intermediates including the macrocycle were obtained and indicates the formation of the compounds.
After synthesizing the ligand 1 , the Fe-complex 2 was developed. Ligand 1 was first deprotonated using a strong base and reacted with ferrous chloride in dry tetrahydrofuran. More specifically, 1 (200 mg, 0.61 mmol) was dissolved in 30 mL dry THF in a 100 mL Schlenk flask containing a magnetic stir bar and fitted with an N 2 gas line. The mixture was cooled to 0° C. using an ice bath. To this mixture was added n-butyllithium (2.56 mmol, 1 mL) and the reaction mixture was stirred for 15 minutes. After stirring for an additional 15 minutes at room temperature, ferrous chloride (85.217 mg, 0.67 mmol) was added and the solution was allowed to stir overnight under N 2 atmosphere. During the reaction the mixture turned deep brown. After exposing the reaction mixture to air, the desired Fe(III)-complex 2 , which precipitated from the solution, was collected by filtration. The Fe-complex 2 was purified simply by passing through an alumina column.
Electro spray ionization mass spectrum (ESI-MS) of the metal complex was obtained and indicates the formation of the metal complex as shown in the FIG. 3 . The calculated isotopic distribution is shown in FIG. 3 inset and is in full agreement with the actual isotope distribution observed. The composition of the complex was further verified by elemental analysis which is in agreement with that of desired product. Electrochemical study shows that Fe-complex 2 has two electrochemically reversible peaks at E 1/2 =0.64 V (E p =63 mV) and E 1/2 =0.84 V (E p =77 mV) corresponding to two successive one electron oxidations.
The complex is stable in neutral to alkaline aqueous solutions for several days at moderately high temperature (60-70° C.). However, heating of the aqueous solution of the Fe-complex to 90° C. causes the catalyst to demetallate rapidly as indicated by changes in the UV-Vis spectra. Demetallation gives rise to the free ligand, which was verified by 1 H-NMR. This is a limitation of using complex 2 at very high temperature. Macrocyclic ring size of thirteen atoms and amide planarity are critical for hydrolytic stability of iron complexes of deprotonated amide ligands. A tetradentate amide ligand with a ring size of fourteen atoms has been reported but the Fe-complex was found to be extremely unstable in water. In the present invention, complex 2 has been synthesized with a ring size of thirteen atoms and the size provides adequate stability to the Fe-complex in aqueous solution.
The catalytic behavior of the complex as an H 2 O 2 activator in a variety of oxidation processes is shown in FIGS. 4-5 . A working solution of catalyst 2 in Na 2 EDTA carbonate/bicarbonate buffer (pH 10) was prepared for use in all reactions. This was done by adding 66.6 μL of a 15,000 ppm EDTA stock solution and 100 μL of a 0.5 mM solution of catalyst 2 to a 100 mL volumetric flask followed by mixing and dilution with 0.1 M carbonate/bicarbonate buffer (pH 10). Final concentrations of EDTA and catalyst 2 were 10 ppm and 0.5 μM respectively. 2980 μL of this working solution was placed in a quartz cuvette fitted with a magnetic stir bar inside. To this solution was added 10 μL of a 3.6 mM purified dye solution (Final dye concentration: 12 μM). The bleaching experiment was initiated by adding 10 μL of 9.4 M H 2 O 2 to the dye solution in the cuvette yielding a H 2 O 2 concentration of 31.3 mM. The change of absorbance was monitored as a function of time at the specified wavelengths. Similarly bleaching of all the dyes were also checked using H 2 O 2 alone at pH 10 and 11.5.
Several water soluble organic dyes were bleached at room temperature in aqueous carbonate/bicarbonate buffer (pH 10) using complex 2 in presence of H 2 O 2 as primary oxidant. Organic dye (12 μM) and a small amount of catalyst (0.5 μM) were combined in buffer solution and the reaction was initiated by adding H 2 O 2 (3 mM). A small amount of sodium salt of ethylenediamine tetraacetate (EDTA) was added into the reaction mixture to remove any free transition metal ion in the solution and thus minimize hydroxyl radical dominated chemistry. FIG. 4A shows the bleaching of several dyes at room temperature. FIG. 5 shows the list of dyes which were bleached using complex 2 . λ max was the wavelength used to determine bleaching time. Bleaching time is defined to be the time at which both A≦half of initial value and the slope of A vs time curve approaches zero for a chosen λ max . All the reactions were performed in pH 10 or 11.5 carbonate buffer with 10 ppm EDTA, dye concentration of 12 μM, H 2 O 2 concentration 31.3 mM, and catalyst 2 concentration of 0.5 μM at 25° C. Methyl Violet, Clayton Yellow, Orange IV, Napthol B green were bleached rapidly. However, the bleaching of Methyl Orange was very slow. H 2 O 2 alone when tested to bleach the dyes under similar conditions was found to be much slower in bleaching the dyes. FIG. 4A shows the bleaching of Orange IV in presence of H 2 O 2 at pH 10 which shows practically no bleaching of dyes. The catalyst however becomes inactivated after a certain time and bleaching is not as effective as previously reported with Fe-TAML catalysts. The bleaching experiment was also done at pH 11.5 and testing did not show any difference in activity compared to experiments at pH 10.
The ability of the catalysts to remove color from pulp and paper effluent along with H 2 O 2 under ambient conditions was also determined. The pH of the effluent was adjusted to 9.5 using concentrated sodium hydroxide solution. To 100 mL of the effluent solution was added 600 μL 2.17 mM solution of catalyst 2 . 300 μL 9.4 M hydrogen peroxide was added to this solution and stirred at room temperature for 4 hours. As a control, to another 100 mL effluent solution, was added 300 μL 9.4 M hydrogen peroxide that was also stirred for 4 hours at room temperature. The solutions were diluted and absorbances of the solutions were measured and compared to the unbleached solutions. Absorbances at 466 nm were recorded and used to calculate color disappearance. FIG. 4B revealed that catalyst 2 (13 μM; 6 mg catalyst/L effluent) can remove 52% color (calculated using absorbance at 466 nm) of the effluent within 4 hours at pH 9.5. H 2 O 2 itself can also remove color under similar reaction conditions although bleaching is less (30%).
FIG. 6 shows the oxidization of a tertiary amine to its corresponding N-oxides, which have tremendous usefulness both in synthetic and biological applications. The reactions were carried out at pH 10 using catalyst 2 and H 2 O 2 at room temperature. The reactions show turn over numbers of 667 with very good yields of N-oxides. For comparison, amines were also oxidized with only hydrogen peroxide. The N-oxides (products) and reactants (amines) were checked after the reaction either by GC/MS or ESI-MS. Pyridine (0.05 mL, 0.620 mmol) was added to 1 mL 0.1 M carbonate/bicarbonate buffer. To this solution was added 0.34 mL of 9.4 M hydrogen peroxide (3.10 mmol) and 0.36 mL of 2.15×10 −3 M of catalyst 2 (0.775 μmol). The solution was stirred at room temperature for 2 hours. An aliquot of the solution was added to acetonitrile, filtered and analyzed by GC/MS to check the N-oxide of pyridine. Product formation was checked by LC/MS too. No other detectable product was observed under the reaction condition. Quantification of product was performed by checking the disappearance of pyridine by GC/MS. As shown in FIG. 7 , a turn over number (TON=Moles of product formed/moles of catalyst) of 407 was observed for pyridine-N-oxide synthesis. Under the reaction conditions, 50.8% yield of product was obtained. When hydrogen peroxide alone was used, only 20% yield was obtained under similar conditions. In case of trienthylamine, a higher TON of 667 was obtained with 66.67% yield. 4-Dimethylaminopyridine was also used for the reaction. Corresponding N-oxide formation was checked by mass spectrometer but not quantified.
The Fe-Complex may be used as an activator of hydrogen peroxide for oxidation purposes, including without limitation, (a) pulp and paper effluent bleaching, (b) dye bleaching, and (c) small molecule synthesis by oxidation (e.g. N-oxides, epoxides, aldehydes and the like may be synthesized from the oxidation of suitable precursor molecules).
The present invention has been described with reference to certain preferred and alternative embodiments that are intended to be exemplary only and not limiting to the full scope of the present invention as set forth in the appended claims. | A tetradendate amide based macrocyclic ligand and its Fe(III) complex which act as activators of hydrogen peroxide. The synthetic methodology to develop the ligands is new, simple and provides better yield for each step of the ligand synthesis. The Fe(III)-complexes and hydrogen peroxide together are can perform several environmentally benign oxidation reactions. Organic dye bleaching, bleaching of pulp and paper effluent and N-oxide synthesis may be performed using the newly developed catalyst and hydrogen peroxide. Alcohol oxidation and alkene epoxidation may also be performed using the catalysts and hydrogen peroxide. | 3 |
BACKGROUND
[0001] Underarm antiperspirant and deodorant products are available in a variety of types, including gels, solids, and liquids that are rolled on. In such liquid, roll-on products, a dispenser is provided, which generally includes a housing and an applicator. The applicator may include a roll-on ball that supplies the liquid product onto the user. The housing generally contains a reservoir of the liquid, which, when the dispenser is inverted, may employ gravity to force the liquid to contact the applicator and flow along the applicator and ultimately to the intended surface (i.e., the underarm), where it may be spread via the rolling motion.
[0002] The packaging of such products, however, may result in a large amount of waste. Typically, the dispenser is designed for a single use. When the reservoir is emptied, the dispenser is thrown away. To avoid such waste, some designs may provide refill cartridges. The refill cartridges may be integrated into the dispenser housing or used to refill the reservoir, e.g., from outside the dispenser. Both options, however, have drawbacks, in terms of ease of use and manufacturing. For example, such refill cartridges may be susceptible to spillage during refill.
BRIEF SUMMARY
[0003] Embodiments of the present disclosure may provide a dispenser and/or refill cartridge for precision application of fluids, for example, for use with roll-on, underarm deodorant products. The dispenser may include a check valve, such as a self-sealing rubber valve, that extends through a wall of the dispenser. In some cases, the wall may be the “bottom” of the dispenser, e.g., opposite an applicator attached to the dispenser. The dispenser may include a dispenser reservoir therein, with the check valve communicating with the reservoir. The dispenser may also include a pressure relief valve configured to release gas contained in the reservoir when it exceeds a certain pressure.
[0004] The cartridge may include a refill reservoir and a valve-piercing element. The valve-piercing element may extend outwards and communicate with the reservoir. The valve-piercing element may be, for example, a hollow elongate structure (e.g., a hollow needle), with an outlet on or near a distal tip thereof.
[0005] To refill the dispenser reservoir, the valve-piercing element may be received through the check valve, such that the check valve seals with an outside of the valve-piercing element. The dispenser may then be actuated (e.g., squeezed) to discharge the fluid contained therein through the valve-piercing element, out the outlet, and into the dispenser reservoir. Air in the dispenser reservoir may be compressed by the introduction of the fluid from the dispenser, and may discharge through the pressure relief valve when the pressure exceeds a certain level, thereby avoiding the buildup of pressure that might otherwise oppose continued entry of the fluid from the refill cartridge reservoir into the dispenser reservoir.
[0006] Further areas of applicability of the present invention will become apparent from the detailed description provided hereinafter. It should be understood that the detailed description and specific examples, while indicating the preferred embodiment of the invention, are intended for purposes of illustration only and are not intended to limit the scope of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] The present invention will become more fully understood from the detailed description and the accompanying drawings, wherein:
[0008] FIG. 1 illustrates a conceptual, cross-sectional view of a refillable dispenser system, according to an embodiment.
[0009] FIG. 2 illustrates a conceptual, cross-sectional view of the system in a refill configuration, according to an embodiment.
DETAILED DESCRIPTION
[0010] The following description of the preferred embodiment(s) is merely exemplary in nature and is in no way intended to limit the invention, its application, or uses.
[0011] As used throughout, ranges are used as shorthand for describing each and every value that is within the range. Any value within the range can be selected as the terminus of the range. In addition, all references cited herein are hereby incorporated by referenced in their entireties. In the event of a conflict in a definition in the present disclosure and that of a cited reference, the present disclosure controls.
[0012] FIG. 1 illustrates a conceptual, cross-sectional view of a refillable dispenser system 100 configured for use, for example, with non-compressible fluidic underarm deodorant or antiperspirant products such as a liquid or a gel, according to an embodiment. The system 100 generally includes a dispenser 102 and a refill cartridge 104 . The dispenser 102 may include a housing 106 that defines a dispenser reservoir 108 therein, which may be configured to contain a fluid (e.g., a non-compressible fluidic deodorant, such as a liquid or a gel). The dispenser reservoir 108 may be fluidly coupled with an applicator 110 , such that fluid in the dispenser reservoir 108 may be conveyed to the applicator 110 and dispensed therefrom. The applicator 110 may be any suitable shape, size, etc., for example, a ball or sphere, as shown, which may rotate about one or more axes relative to the housing 106 . The fluid in the dispenser reservoir 108 may have any suitable viscosity and may be any suitable deodorant, antiperspirant, or any other fluid suitable for the application in which it is used. In one embodiment, the fluid is at a constant ambient pressure inside the reservoir 108 , i.e., the reservoir 108 is not pressurized.
[0013] The housing 106 may be fabricated at least partially from a plastic, for example, an injection or otherwise molded plastic. However, in other embodiments, any suitable material for the housing 106 may be employed. Further, the dispenser 102 may include any membranes, pistons, bags, ducts, etc. as may be desired to contain the fluid in the dispenser reservoir 108 and dispense it via the applicator 110 as needed.
[0014] The dispenser 102 may also include a check valve 112 for example, on a side opposed to the applicator 110 , which may be referred to as the “bottom” of the dispenser 102 , regardless of the actual orientation or attitude of the dispenser 102 . In other embodiments, the check valve 112 may be positioned on a side of the dispenser 102 . The check valve 112 may be, for example, a self-sealing elastomeric (e.g., rubber) valve. In one specific example, the check valve 112 may be analogous in form and/or function to a self-sealing inflation valve, such as those seen in inflatable balls. In an embodiment, the check valve 112 may include a base 114 and a body 115 extending therefrom and defining a one-way conduit 116 therethrough. Further, the body 115 may include a receiving end 118 coupled with the base 114 and a sealing end 120 , distal to the base 114 . The conduit 116 may communicate with an exterior of the housing 106 at the receiving end 118 , and may communicate with the dispenser reservoir 108 at the sealing end 120 . For example, the conduit 116 may extend into the reservoir 108 .
[0015] Further, the conduit 116 may taper from an open diameter at the receiving end 118 , to substantially a zero diameter at the sealing end 120 . The taper may be gradual along the extent of the conduit 116 , or may be more abrupt, e.g., toward the middle of the conduit 116 , as shown. With the sealing end 120 having a zero diameter, the sealing end 120 may be closed, thereby sealing the check valve 112 . The conduit 116 may, however, be flexible at least near the sealing end 120 , so as to expand from the zero diameter by introduction of an expansion force, thereby opening the sealing end 120 . In other embodiments, other types of self-sealing check valves may be employed, such as flapper valves.
[0016] The dispenser 102 may also include a pressure relief valve 122 , which may also communicate with the reservoir 108 and an exterior of the housing 106 , for example, by extending through the housing 106 . The pressure relief valve 122 may have a valve element 125 , which may be or include a flapper, ball, membrane, or another type of valve element that may be biased to a sealing position, or the like. The valve element 125 may be biased to a sealing position, such that the pressure relief valve 122 is closed as a default. When a pressure within the reservoir 108 applies a force on the valve element 125 that exceeds the force holding the valve element 125 in a sealed configuration, the pressure relief valve 122 may open, thereby releasing fluid (e.g., air) from the reservoir 108 to the exterior of the housing 106 .
[0017] Turning to the cartridge 104 , the cartridge 104 may include a pouch 124 and a valve-piercing element 126 . The pouch 124 may define a refill reservoir 128 therein, which may contain a fluid and may fluidly communicate with the valve-piercing element 126 . Further, the pouch 124 may be flexible, such that squeezing the pouch 124 may result in an increased pressure on fluid in the refill reservoir 128 . In some instances, however, at least a portion of the pouch 124 may be rigid, so as to facilitate applying a moving force to the cartridge 104 , as will be explained in greater detail below. Further, in some embodiments, the cartridge 104 may include a piston or another actuation device that may be configured to reduce a volume of the refill reservoir 128 . In some embodiments, the refill reservoir 128 contains a non-compressible and/or non-pressurized fluidic deodorant, such as a liquid or a gel.
[0018] The valve-piercing element 126 may have a proximal end 130 coupled with the pouch 124 , and may extend to a distal end 132 , opposite the proximal end 130 . Further, the valve-piercing element 126 may define a generally hollow, elongate body 134 between the ends 130 , 132 , which may define a conduit 136 extending therethrough. The cartridge 104 may also define a check valve 135 , which may, for example, be one or more flappers that serve to retain fluid in the reservoir 128 until the fluid in the reservoir 128 is at a predetermined, heightened pressure (e.g., when the pouch 124 is squeezed or otherwise actuated), which may open the check valve 135 and release the fluid therethrough, as will be explained in greater detail below. In other embodiments, the check valve 135 may be a piece of the pouch 124 that is configured to rupture at the predetermined pressure. In still other embodiments, the pouch 124 may be punctured during or prior to assembling the valve-piercing element 126 with the pouch 124 . In other cases, the check valve 135 may be unnecessary and omitted.
[0019] The valve-piercing element 126 may define an opening 138 at the distal end 132 , which may communicate with the conduit 136 . Accordingly, the refill reservoir 128 may communicate with the opening 138 via the conduit 136 so as to, for example, expel fluid through the valve-piercing element 126 and out of the opening 138 . In other embodiments, the opening 138 may be formed along the body 134 , near the distal end 132 , such that the distal end 132 may be rounded, so as to protect the check valve 112 during insertion.
[0020] FIG. 2 illustrates a conceptual, cross-sectional view of the system 100 , with the valve-piercing element 126 of the cartridge 104 received into the check valve 112 , i.e., a “refill” configuration, according to an embodiment. To insert the valve-piercing element (i.e., to move from the configuration shown in FIG. 1 to that shown in FIG. 2 ), a movement force is applied to either or both of the dispenser 102 and the cartridge 104 . Under this force, the valve-piercing element 126 is slid into the receiving end 118 of the check valve 112 . As the valve-piercing element 126 slides, it may expand the elastic construction of the check valve body 115 (or push aside a flapper valve of the check valve 112 , etc.), thereby increasing the diameter of the conduit 116 . Upon reaching the sealing end 120 , the continued sliding of the valve-piercing element 126 may expand the sealing end 120 from the zero diameter of the sealed configuration to an open configuration, as the valve-piercing element 126 extends therethrough.
[0021] When fully inserted, the opening 138 of the valve-piercing element 126 may be disposed in on otherwise communicate with the dispenser reservoir 108 . Further, the check valve body 115 may be sealed around the body 134 of the valve-piercing element 126 , so as to prevent fluid transmission between the bodies 134 and 115 in the conduit 116 . The cartridge 104 may then be actuated, so as to deploy the fluidic contents of the refill reservoir 128 through the valve-piercing element 126 , out the opening 138 , and into the dispenser reservoir 108 .
[0022] As the fluid from the refill reservoir 128 is received into the dispenser reservoir 108 , air in the reservoir may be compressed as the generally incompressible (or, at least less compressible) fluid received into the reservoir 108 reduces the available volume for the air. The energy for such compression may be provided by the force applied to the cartridge 104 causing the fluidic contents to be expelled. When the pressure of the air in the dispenser reservoir 108 exceeds a certain threshold, the air may displace the valve element 125 from its seat in the pressure relief valve 122 , thereby allowing air to escape through the pressure relief valve 122 , until the pressure is reduced to below the threshold level, whereupon the valve element 125 may again close, to avoid loss of the fluidic contents therethrough.
[0023] When the reservoir 108 is filled, or the reservoir 128 is empty, or at any other point during refill, the actuation of the refill cartridge 104 may be terminated, and the valve-piercing element 126 slid out of the check valve 112 . The resilient construction of the check valve body 115 may result in the conduit 116 once again being closed off, thereby preventing the contents of the reservoir 108 from escaping through the check valve 112 . | A system ( 100 ) for dispensing a fluid, such as a deodorant is provided. The system ( 100 ) includes a dispenser ( 102 ) defining a first reservoir ( 108 ) therein and comprising a check valve ( 112 ) communicating with the first reservoir ( 108 ) and an exterior of the dispenser ( 102 ). The system ( 100 ) also includes a refill cartridge ( 104 ) defining a second reservoir ( 128 ) therein and including a valve-piercing element ( 126 ) configured to be received through the check valve ( 112 ), such that, when the valve-piercing element ( 126 ) is received through the check valve ( 112 ), the second reservoir ( 128 ) of the refill cartridge ( 104 ) fluidly communicates with the first reservoir ( 108 ) of the dispenser ( 102 ) via the valve-piercing element ( 126 ). | 0 |
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims the priority, under 35 U.S.C. §119, of German application DE 10 2007 028 162.7, filed Jun. 20, 2007; the prior application is herewith incorporated by reference in its entirety.
BACKGROUND OF THE INVENTION
FIELD OF THE INVENTION
[0002] The invention relates to a fastening device for an internal rear view mirror of motor vehicles to be attached to an inner side of a windshield. The fastening device has a holding part which is held in position by adhesive bonding being provided on the windshield, to which holding part is detachably fastened a mirror foot of the internal rear view mirror.
[0003] Published, non-prosecutred German patent application DE 20 15 608 A discloses a fastening device for an internal rear view mirror of motor vehicles, with a plastic plate-shaped holding part with a rectangular outline being fastened to the inner side of a windshield by adhesive bonding. Undercut V-shaped holding grooves are provided at two spaced-apart side edges, which are aligned parallel to one another, of the holding part, into which holding grooves correspondingly formed plug-in edges of the mirror foot can be inserted.
[0004] In order to ensure the sliding of the mirror foot onto the holding part and in order to compensate tolerances between the two components, the side edges of the V-shaped holding grooves are kept relatively thin so that they can elastically deflect during the assembly of the mirror foot.
[0005] On account of the elastic formation of the holding part in regions, the fastening device has a relatively low rigidity in the holding part/mirror foot connecting region, as a result of which, in dynamic driving operation of the vehicle, disturbing mirror glass vibrations can occur. In addition, the fastening device is statically overdetermined.
SUMMARY OF THE INVENTION
[0006] It is accordingly an object of the invention to provide a fastening device for an internal rear view mirror of motor vehicles to be attached to an inner side of a windshield that overcomes the above-mentioned disadvantages of the prior art devices of this general type, in which the connection between the holding part and mirror foot is statically precisely defined and has a high rigidity, so that the mirror glass vibration behavior in driving operation is considerably improved.
[0007] With the foregoing and other objects in view there is provided, in accordance with the invention, a fastening device for an internal rear view mirror of motor vehicles to be installed on an inner side of a windshield. The fastening device contains a six-point support, a separate retaining device, and a holding part held in position by adhesive bonding provided on the windshield, to the holding part is detachably fastened a mirror foot of the internal rear view mirror. The mirror foot, in a mounted operating position, is supported directly on the holding part merely by the six-point support and is fastened to the holding part by the separate retaining device.
[0008] The advantages primarily achieved by the invention are to be considered those of a statically precisely defined, highly rigid connection being created by the six-point support between the holding part and mirror foot, by which connection low mirror glass vibrations are ensured in dynamic driving operation. Simple and fast mounting of the internal rear view mirror on the holding part is created by a bayonet-like retaining device. On account of the self-centering connection, no incorrect assembly of the mirror foot is possible. As a result of the freedom from play of the connection, the mirror foot cannot rotate during adjustment of the mirror head.
[0009] In accordance with an added feature of the invention, the six-point support has in each case three support elements disposed offset with respect to one another, which are of a projecting configuration, and are provided on each of the holding part and on the mirror foot. The support elements of one of the holding part and the mirror foot have in each case projecting prismatic guides. The support elements of the other one of the holding part and the mirror foot have correspondingly configured holding grooves being recessed, the projecting prismatic guides interact in a form-fitting manner with the correspondingly configured holding grooves. The projecting prismatic guides have a shape of a triangular prism. The projecting prismatic guides are provided on the support elements of the mirror foot. The correspondingly configured holding grooves are formed in the support elements of the holding part. The projecting prismatic guides each have two projecting side faces running at an angle with respect to one another, with the angle being between 60° and 120°. Ideally, the three support elements of the holding part and of the mirror foot run in each case at an angle of 120° with respect to one another.
[0010] In accordance with an additional feature of the invention, the holding part has a collar being annular in regions, and the support elements of the holding part are integrally formed on that side of the collar facing away from the windshield.
[0011] In accordance with another feature of the invention, the support elements of the mirror foot are formed on that end side of the mirror foot which faces toward the holding part.
[0012] In accordance with a further feature of the invention, insertion bevels are provided in each case on the support elements of the holding part and of the mirror foot in front of the projecting prismatic guides and the correspondingly configured holding grooves.
[0013] In accordance with another further feature of the invention, the holding part has radially disposed latching grooves, and the separate retaining device has a retaining element connected to the mirror foot. The retaining element has at least two resilient retaining tongues bent in a direction of the holding part and which, when the mirror foot is mounted, engage into the radially disposed latching grooves of the holding part.
[0014] In accordance with another added feature of the invention, the retaining element has an annular base section supported on and connected to an end side of the mirror foot. The retaining element has three profiled retaining tongues disposed in a stellate fashion with respect to one another.
[0015] In accordance with another further feature fo the invention, the radially disposed latching grooves are provided locally on an outer side of the collar of the holding part.
[0016] In accordance with a concomitant feature of the invention, the holding part has free cut-out regions formed therein disposed in front of the radially disposed latching grooves.
[0017] Other features which are considered as characteristic for the invention are set forth in the appended claims.
[0018] Although the invention is illustrated and described herein as embodied in a fastening device for an internal rear view mirror of motor vehicles on an inner side of a windshield, it is nevertheless not intended to be limited to the details shown, since various modifications and structural changes may be made therein without departing from the spirit of the invention and within the scope and range of equivalents of the claims.
[0019] The construction and method of operation of the invention, however, together with additional objects and advantages thereof will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0020] FIG. 1 is a diagrammatic, perspective oblique view of an internal rear view mirror of a motor vehicle from the rear and above according to the invention,
[0021] FIG. 2 is a sectional view taken along the line II-II shown in FIG. 1 in an enlarged illustration and rotated;
[0022] FIG. 3 is an exploded, perspective view of the internal rear view mirror, a sensor element and a holding part;
[0023] FIG. 4 is a sectional view taken along the line IV-IV shown in FIG. 1 ;
[0024] FIG. 5 is a perspective oblique view similar to FIG. 1 , with the mirror foot and the retaining element which is fastened to the mirror foot being illustrated;
[0025] FIG. 6 is a perspective view from below of the holding part which is fastened to the windshield; and
[0026] FIG. 7 is an enlarged sectional view of detail X shown in FIG. 2 .
DETAILED DESCRIPTION OF THE INVENTION
[0027] Referring now to the figures of the drawing in detail and first, particularly, to FIGS. 1 and 2 thereof, there is shown a fastening device 1 for an internal rear view mirror 2 of motor vehicles, with the internal rear view mirror 2 being fastened to the inner side 3 of a windshield 4 with the interposition of a holding part 5 . The internal rear view mirror 2 is composed of a mirror foot 6 and a mirror head 7 which is articulatedly connected thereto. The holding part 5 , which has a low installation height, is fastened by adhesive bonding to the inner side 3 of the windshield 4 and, in the exemplary embodiment, is produced from a fiber-reinforced plastic. The holding part 5 could however also be produced from a sintered metal.
[0028] An upper planar face 8 of the holding part 5 is connected by an adhesive layer or an adhesive foil to the inner side 3 of the windshield 4 . The holding part 5 serves for retaining and supporting the internal rear view mirror 2 . In the exemplary embodiment, the holding part 5 which is of an annular configuration in regions has a central cutout 9 . Inserted into the cutout 9 is a sensor element 10 which, when the internal rear view mirror 2 is mounted, is pressed by a non-illustrated pressing spring with a preload against the inner side 3 of the windshield 4 (see FIGS. 3 , 4 ). The sensor element 10 can contain one or more sensors. In the exemplary embodiment, the sensor element 10 has a rain sensor, a light sensor and a humidity sensor.
[0029] The shape of the cutout 9 is matched to the outer contour of the sensor element 10 , so that the latter is positioned in the cutout 9 of the holding part 5 so as to be correctly located and immovable.
[0030] According to the invention, the mirror foot 6 , in its mounted operating position A, is supported directly on the holding part 5 merely by a six-point support 11 and is fastened to the holding part 5 by a separate retaining device 12 . In order to form the six-point support 11 , in each case three support elements 13 , 14 which are disposed offset with respect to one another and which are of a projecting configuration are provided on the holding part 5 and on the mirror foot 6 . In each case projecting prismatic guides 15 are formed on the support elements 13 , 14 of the mirror foot 6 or of the holding part 5 , which prismatic guides 15 interact in a form-fitting manner with correspondingly configured holding grooves 16 , which are disposed so as to be recessed, of the in each case other part.
[0031] In the exemplary embodiment, the prismatic guides 15 have the shape of a triangular prism 17 (see FIG. 7 ). The two projecting side faces 18 , 19 of each triangular prism 17 , which side faces 18 , 19 extend obliquely downward from a common theoretical corner point 20 , form two support faces, which run at an angle a with respect to one another, of the support element 13 , 14 of the six-point support 11 . The side faces 18 , 19 of the prismatic guides 15 run at an angle a with respect to one another, with the angle a being between 60° and 120°. The two side faces 18 , 19 are of approximately the same length.
[0032] In the exemplary embodiment, the projecting prismatic guides 15 are provided on the support elements 14 of the mirror foot 6 , whereas the holding grooves 16 which are disposed so as to be recessed are formed on the support elements 13 of the holding part 5 . The arrangement of the prismatic guides 15 and the holding grooves 16 can however also be reversed. The correspondingly formed side faces 21 , 22 , which are disposed so as to be recessed, of the holding grooves 16 likewise form two support faces, which run obliquely with respect to one another, of a support element 13 , 14 of the six-point support 11 . The two side faces 18 , 19 of the prismatic guides 15 are connected to one another by a radial transition region 23 , with the radius of the transition region 23 being greater than the relatively small radius between the two side faces 21 , 22 of the holding grooves 16 .
[0033] In the exemplary embodiment, the mirror foot 6 rests, at each of its three support elements 14 , with the obliquely-running side face 18 in regions on the co-aligned side face 21 of the support element 13 , whereas the side face 19 , which runs at an angle with respect to the side face 18 , of the support element 14 is supported on the co-aligned side face 22 of the support element 13 disposed on the holding part 5 . Between the three support elements 13 , 14 which are disposed in each case in pairs, the holding part 5 runs with an axial spacing (dimension B) with respect to the mirror foot 6 .
[0034] The three support elements 13 , 14 which are formed in each case in one piece with the holding part 5 and with the mirror foot 6 are disposed in a stellate fashion with respect to a theoretical central point and are offset with respect to one another in each case by 90° to 135°, preferably by approximately 120°. The support elements 13 of the holding part 5 are integrally formed on that side of a collar 24 , which is of an annular configuration in regions, of the holding part 5 which faces away from the windshield 4 . The support parts 14 of the mirror foot 6 , which is preferably produced from an aluminum alloy or from plastic, are integrally formed on that end side 25 of the mirror foot 6 which faces toward the holding part 5 . Insertion bevels 26 , 27 are formed in each case on the support parts 13 , 14 of the holding part 5 and of the mirror foot 6 in front of the prismatic guides 15 and the holding grooves 16 , with the insertion bevel 26 being assigned to the prismatic guide 15 and the insertion bevel 27 being assigned to the holding groove 16 . The end sides 28 , 29 , which are aligned toward one another, of in each case two corresponding support elements 13 , 14 run with a slight axial spacing (dimension C), so that the holding part 5 and the mirror foot 6 rest or are supported locally on one another merely at six obliquely-running bearing faces.
[0035] The retaining device 12 for the mirror foot 6 contains a retaining element 30 which is connected to the mirror foot 6 , which retaining element 30 has at least two resilient retaining tongues 31 which are bent in the direction of the holding part 5 and which, when the mirror foot 6 is mounted, engage into radially arranged latching grooves 32 of the holding part 5 so as to engage behind these (see FIG. 4 ). The retaining element 30 , with an annular base section 33 , rests on and is connected to the substantially planar end side 25 of the mirror foot 6 . In the exemplary embodiment, the base section 33 is connected by two spaced-apart screw fastenings (not illustrated in any more detail) to the mirror foot 6 . According to FIG. 5 , the retaining element 30 has resilient retaining tongues 31 which are arranged in a stellate fashion with respect to one another. Latching grooves 32 are provided locally on the outer side of the annular collar 24 of the holding part 5 . In each case free cut-out regions 34 are provided on the holding part 5 in front of the latching grooves 32 , in order that the retaining tongues 31 of the mirror foot 6 can be placed into a pre-latched position. The mirror foot 6 is fixed to the holding part 5 by a subsequent rotation of the mirror foot 6 relative to the holding part 5 by an angle of approximately 10° to 20° clockwise. The fixing of the mirror foot 6 takes place in principle in the same way as the bayonet connection for an objective lens. The mirror foot 6 , the holding part 5 and the retaining element 30 are for the most part encased by a multi-part cover 35 which is fastened to the mirror foot 6 (for example by being plugged on or clipped on) after the mounting of the internal rear view mirror 2 (see FIG. 4 ). | A fastening device for an internal rear view mirror of motor vehicles to be installed on an inner side of a windshield contains a holding part which is held in position on the windshield by adhesive bonding, to which holding part is detachably fastened a mirror foot of the internal rear view mirror. In order to obtain a statically precisely defined, highly rigid connection between the holding part and mirror foot, it is provided that the mirror foot, in its mounted operating position, is supported directly on the holding part merely by a six-point support and is fastened to the holding part by a separate retaining device. | 1 |
REFERENCE TO RELATED APPLICATIONS
The invention disclosed in this application has particular, but not necessarily limited application to the continuously variable hydrostatic transmissions disclosed in copending U.S. patent applications, Ser. Nos. 08/093,192, filed Jul. 13, 1993 and now U.S. Pat. No. 5,423,183, issued Jun. 13, 1995; 08/333,688, filed Nov. 3, 1994 (now allowed); 08/342,472, filed Nov. 21, 1994; and 08/380,276, filed Jan. 30, 1995, filed concurrently herewith. The disclosures of these applications are incorporated herein by reference.
FIELD OF THE INVENTION
The present invention relates to hydraulic machines and, more particularly, to hydrostatic transmissions capable of transmitting power from a prime mover to a load at continuously (infinitely) variable transmission ratios.
BACKGROUND OF THE INVENTION
The continuously variable hydrostatic transmissions disclosed in the cited copending applications include a hydraulic pump unit and a hydraulic motor unit positioned in opposed, axially aligned relation with an intermediate, wedge-shaped swashplate. The pump unit is connected to an input shaft driven by a prime mover, while the motor unit is grounded to the stationary machine housing. An output shaft, coaxial with the input shaft and drivingly coupled to a load, is connected to the swashplate. When the pump unit is driven by the prime mover, hydraulic fluid is pumped back and forth between the pump and motor units through ports in the swashplate. As a result, three torque components, all acting in the same direction, are exerted on the swashplate to produce output torque on the output shaft for driving the load. Two of these torque components are a mechanical component exerted on the swashplate by the rotating pump unit and a hydromechanical component exerted on the swashplate by the motor unit. The third component is a pure hydrostatic component resulting from the differential forces created by the fluid pressures acting on circumferentially opposed end surfaces of the swashplate ports, which are of different surface areas due to the wedge shape of the swashplate.
To change transmission ratio, the angular orientation of the swashplate relative to the axis of the output shaft is varied by a ratio controller. Since the transmission ratio, i.e., ratio of input speed to output speed, is continuously variable between 1:0 and 1:1, the prime mover can run at a constant speed set essentially at its most efficient operating point. The availability of a 1:0 (neutral) transmission ratio setting eliminates the need for a clutch. As is disclosed in cited application Ser. No. 08/342,472, the swashplate can be positioned to angular orientations beyond the 1:0 ratio setting to provide limited infinitely variable speed drive in a reverse direction, as well as to angular orientations beyond the 1:1 setting to provide a limited, infinitely variable, overdrive speed range. Significantly, reverse drive is available without need for a reversing gear mechanism.
Unlike conventional, continuously variable hydrostatic transmissions, wherein hydraulic fluid flow rate increases proportionately with increasing transmission ratio such that maximum flow rate occurs at the highest transmission ratio setting, the flow rate in the transmissions disclosed in the cited applications reaches a maximum at a midpoint in the ratio range and then progressively decreases to essentially zero at the 1:1 transmission ratio setting. Thus, losses due to hydraulic fluid flow are reduced, and the annoying whine of conventional hydrostatic transmissions at high ratios is avoided. By virtue of the multiple torque components exerted on the swashplate, the decreasing hydraulic fluid flow in the upper half of the output speed range, and the capability of accommodating a prime mover input operating at or near its optimum performance point, the hydraulic machines of the cited U.S. patent applications have a particularly advantageous application as a highly efficient, quiet, continuously variable hydrostatic transmission in vehicular drive trains.
SUMMARY OF THE INVENTION
An objective of the present invention is to provide an improved ratio controller for controlling a hydrostatic transmission to achieve continuously variable ratios of input versus output speeds.
A further objective of the present invention is to provide an improved ratio controller for effectively controlling the rate of ratio change of a continuously variable hydrostatic transmission in response to speed command signals.
An additional objective of the present invention is to provide an improved ratio controller for changing the swashplate angle in continuously variable hydrostatic transmissions of the type disclosed in the cited U.S. patent applications.
To achieve these objectives, the ratio controller of the present invention, in its application to a continuously variable hydrostatic transmission including an input shaft for receiving input torque from a prime mover, an output shaft for imparting driving torque to a load, a hydraulic pump unit, a hydraulic motor unit, and a swashplate operatively positioned between the pump unit and the motor unit, comprises, in combination, an actuator including a cylinder and a piston disposed in the cylinder to define first and second chambers, the actuator operatively coupled to the swashplate; a first fluid valve having a quiescent valve position connecting the first chamber to a source of hydraulic fluid pressure and an actuated valve piston venting the first chamber; a second fluid valve having a quiescent valve position connecting the second chamber to the fluid pressure source and actuated valve position venting the second chamber; a module, responsive to speed commands, for selectively actuating the first and second solenoid valves to create differential fluid pressures in the first and second chambers and thereby produce controlled relative motion of the cylinder and piston; and means for translating the relative motion of the cylinder and piston into ratio-changing movement of the swashplate.
Further in accordance with these objectives, the present invention provides a method for controlling input-to-output speed ratio of a continuously variable hydrostatic transmission having a swashplate operatively positioned between a hydraulic pump unit and a hydraulic motor unit, the method including the steps of linking an actuator to the swashplate, the actuator including a piston received in a cylinder to define first and second chambers; providing a source of pressurized hydraulic fluid; providing a first fluid valve having a quiescent valve position connecting the first chamber to the source of pressurized hydraulic fluid and an actuated valve position venting the first chamber; providing a second fluid valve having a quiescent valve position connecting the second chamber to the pressurized hydraulic fluid source and an actuated valve position venting the second chamber; setting a transmission ratio by maintaining the first and second fluid valves in their quiescent valve positions to equalize fluid pressures in the first and second chambers; changing the transmission ratio by shifting one of the first and second valves to its actuated position, thereby creating differential fluid pressures in the first and second chambers to produce relative motion of the piston and cylinder; and translating the relative piston and cylinder motion into transmission ratio-changing movement of the swashplate.
Additional features, advantages, and objectives of the invention will be set forth in the description which follows and in part will be apparent from the description, or may be learned by practice of the invention. The objectives and advantages of the present invention will be realized and attained by the apparatus and method particularly pointed out in the following written description and the appended claims, as well as in the accompanying drawing.
It will be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are intended to provide further explanation of the invention as claimed.
The accompanying drawing is intended to provide a further understanding of the invention and is incorporated in and constitutes a part of the specification, illustrates a preferred embodiment of the invention and, together with the description, serves to explain the principles of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
The sole FIGURE of the drawing is a schematic diagram of a ratio controller according to an embodiment of the present invention in its application to a continuously variable hydrostatic transmission.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
The transmission ratio controller in accordance with a preferred embodiment of the present invention, as generally indicated at 10 in the drawing, is illustrated in its application to a continuously variable transmission, generally indicated at 12 and of the type disclosed in the cited U.S. patent applications. Thus, as diagrammatically illustrated in the drawing, transmission 12 includes a housing 14 in which are journaled an input shaft 16 and an output shaft 18 in generally end-to-end, coaxial relation. Input shaft 16 applies input torque from a prime mover (not shown) to a hydraulic pump unit, generally indicated at 20, while a hydraulic motor unit, generally indicated at 22, is grounded to housing 14, as indicated at 24. Operatively positioned between pump unit 20 and motor unit 22 is a wedge-shaped swashplate 26, which is pivotally connected to the output shaft in torque coupled relation as indicated at 28. As described in the cited U.S. patent applications, swashplate 26 is provided with ports through which hydraulic fluid is pumped back and forth between the hydraulic pump and motor units to exert torque components on the swashplate, which are coupled to output shaft 18 as output torque for application to driving wheels of a vehicle (not shown). As also described in the cited U.S. patent applications, transmission ratio, i.e., input speed on input shaft 16 versus output speed on output shaft 18, is determined by swashplate angle, that is, the angular orientation of swashplate 26 relative to the output shaft axis 19. Thus, to change transmission ratio, swashplate 26 is pivoted about its pivotal connection 28 to output shaft 18, as indicated by arrow 27, to decrease ratio (clockwise) or to increase ratio (counterclockwise).
Ratio controller 10 comprises a hydraulic actuator 30, positioned within housing 14, a pair of solenoid valves, generally indicated at 32 and 34, for connecting chambers of the actuator to either a common source of hydraulic fluid under pressure or to atmosphere, and a module 36 connected to selectively energize the solenoid valves in response to speed command signals.
Actuator 30 is illustrated as comprising a cylinder 40 in which a piston 42 is slidingly received to define a pair of opposed chambers 44 and 46. Piston 42 is mounted for reciprocating motion within cylinder 40 by opposed piston rods 48 extending through hermetically sealed openings in the cylinder endwalls. The exterior end of one piston rod 48 is linked, as schematically indicated at 50, to translate reciprocating movement of piston 42 into bidirectional angular movement of swashplate 26 about its pivotal connection 28 to output shaft 18.
It is to be understood that the illustrated actuator structure is exemplary only. It may take a variety of forms, such as, for example, the various forms illustrated in the cited U.S. patent applications. For example, as illustrated in cited application Ser. No. 08/333,668, piston 42 may be fixedly positioned, while cylinder 40 undergoes reciprocating motion and is thus linked to swashplate 26. Cited application Ser. No. 08/342,472 illustrates that piston 42 may represent a pair of spherical bearings that respectively mount pump unit and motor unit cylinder blocks. Coordinated axial movements of the spherical bearings exert pivoting forces on the swashplate via the cylinder blocks. Link 50 may take the form of large diameter cylindrical actuating member that reaches around the pump or motor unit to exert pivoting forces on the swashplate, as illustrated in cited application Ser. No. 08/093,192. Alternatively, the link 50 may include a cylindrical actuating member that closely surrounds output shaft 18, is illustrated in cited application Ser. No. 08/333,688. Cited application Ser. No. (35-OR-962) illustrates link 50 may represent a hydraulically actuated piston incorporated in the output shaft.
Returning to consideration of actuator 30 in its form illustrated herein, chamber 44 is connected to a valve chamber 52 of solenoid valve 32 via a fluid line 54, while chamber 46 is connected to a valve chamber 56 of solenoid valve 34 by a fluid line 58. Valve chambers 52 and 56 are connected in common via fluid lines 60 and 62 to a source of hydraulic fluid pressure, preferable makeup or control pressure available at the output of a sump pump 64. Valve chamber 52 is also vented, via fluid line 66, to atmospheric pressure, such as exists in a transmission sump 68. Valve chamber 56 is likewise vented to sump 68 via fluid line 70.
Solenoid valve 32 also includes a valve member 72 slidingly received in valve chamber 52. A stem 74 extends from valve member 72 externally of valve chamber 52 and is terminated by a solenoid plunger 76. A solenoid coil 78, wound on plunger 76, is grounded at one end and connected at its other end by a lead 80 extending to control module 36. Valve member 72 is biased to an illustrated quiescent position by a spring 82, such that actuator chamber 44 is normally in fluid communication with sump pump 64 via fluid lines 54, 60, and 62.
Solenoid valve 34 is constructed in the same manner as solenoid valve 32, and thus includes a valve member 84 slidingly received in valve chamber 56. A valve stem 86 extends from valve member 84 to a terminating solenoid plunger 88, about which a solenoid coil 90 is wound. The ungrounded end of coil 90 is connected to control module 36 by a lead 92. A spring 94 biases valve member 84 to its illustrated quiescent valve position, thereby connecting actuator chamber 46 in fluid communication with the sump pump output via fluid lines 58, 60, and 62.
From the foregoing description of ratio controller 10, it is seen that, while solenoid valves 32 and 34 are in their quiescent valve positions, actuator chambers 44 and 46 are filled with hydraulic fluid at a fluid pressure equal to the sump pump output pressure. Actuator piston 42 is thus fixed in position to set a particular swashplate angle. When a speed command inputted to control module 36 calls for an increase in transmission ratio, solenoid coil 78 of solenoid valve 32 is electrically energized to propel valve member 72 forwardly to a venting valve position illustrated in phantom line, thereby connecting actuator chamber 44 to sump 68 through fluid lines 54 and 66. The fluid pressure in actuator chamber 46, still connected to sump pump 64 by solenoid valve 34, now exceeds the fluid pressure in actuator chamber 44. Consequently, piston 42 is driven leftward to pivot swashplate 26 in the counterclockwise, ratio-increasing direction. When the swashplate has been pivoted to the commanded higher transmission ratio, control module 36 ceases energization of solenoid coil 78, and solenoid valve 32 is pulled back to its quiescent valve position by spring 82, reconnecting actuator chamber 44 to the sump pump 64. Fluid pressures in the actuator chambers equalize to fix the actuator piston position and set the swashplate position to the new, higher ratio setting.
When a speed input command calls for a reduction in transmission ratio, control module 36 energizes solenoid coil 90 to drive valve member 84 forwardly to its phantom line valve position, thereby venting actuator chamber 46 to sump 68. The fluid pressure in chamber 44 now exceeds the fluid pressure in actuator chamber 46, and actuator piston 42 is driven rightward as the volume of chamber 44 expands, while the volume of chamber 46 contracts. Swashplate 26 is pivoted in the clockwise direction to reduce transmission ratio. When the transmission ratio achieves a setting satisfying the reduced speed command, energization of solenoid valve 34 ceases, and spring 94 retracts valve member 84 to its solid line position reconnecting actuator chamber 46 to the sump pump output. Actuator chamber 46 is then pressurized to the same fluid pressure as actuator chamber 44, and the new position of actuator piston 42 is sustained to set the swashplate angle to the commanded, lower transmission ratio.
As illustrated, orifice restrictions 96 may be incorporated in fluid lines 60, 66, and 70 to adjust operating parameters of the fluid circuit by attenuating hydraulic fluid flow rate and thus avoiding abrupt fluid pressures changes in the actuator chambers. The restrictions also will alleviate the affects of fluid viscosity changes due to variations in operating temperature.
In accordance with a feature of the present invention, control module 36 is in the form of a pulse width modulator that generates a stream of pulses at a constant pulse rate or frequency (e.g. 16 Hz), wherein the pulse width (duty cycle) is varied in response to the input speed command. By varying the pulse duty cycle (ratio of pulse width to pulse period), the duration that one of the solenoid valve members 72 or 84 is in its phantom line position to vent chambers 44 or 46, respectively, the rate at which actuator piston 42 moves to change swashplate angle is varied accordingly. That is, at high pulse duty cycles, the rate of swashplate angle change is correspondingly high, and vice versa. Once the speed command is satisfied, the output pulse stream is stopped to set the swashplate angle at the commanded speed (transmission) ratio.
The capability of precisely controlling the rate of ratio change in transmission 12 using pulse width modulation energization of solenoid valves 32 and 34 is particularly advantageous in automotive applications. That is, ratio controller 10 can readily act not only to continuously match engine power to vehicle load, but also quickly react to such dynamic situation as sudden stops (fast ratio change) and heavy traffic conditions (slow ratio change).
While pulse width modulation of the solenoid energizations is preferred, it will be appreciated that frequency modulation of a stream of uniform width pulses could also be used.
It will be apparent to those skilled in the act that various modifications and variations can be made to the apparatus of the present invention without departing from the spirit of the invention. Thus, it is intended that the present invention be construed to cover modifications and variations thereof, provided they come within the spirit and scope of the appended claims and their equivalents. | A controller for changing the ratio of a continuously variable hydrostatic transmission, as determined by the angular position of a swashplate, including an actuator having a cylinder slidingly receiving a piston to define a pair of chambers. A pair of solenoid valves, each configured to connect a respective chamber selectively to sump pump pressure or atmospheric pressure, are energized with a stream of pulses to create differential fluid pressures in the chambers, thereby producing movement of the piston; the piston movement being linked to the swashplate to produce a corresponding adjustment of the swashplate angular position. The rate of change of the swashplate angular position is controlled by pulse width modulating the pulse stream. | 5 |
This is a division, of application Ser. No. 801,052, filed November 22, 1985.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to photometric chemical analyzers. More particularly, this invention relates to an improved photometric analyzer capable of performing kinetic rate measurements of enzyme activity, end-point determinations of metabolites, and fixed-time substrate analyses.
2. Description of the Prior Art
The measurement of absorbance of light is an important method of analyzing the chemical composition of fluids. This type of measurement is usually performed by passing a narrow bandwidth spectrum of visible light through the fluid under test and measuring the amount of light absorbed by the fluid. The degree of absorption is proportional to the concentration of the chemical component or components which will absorb the particular spectrum being applied. By providing the capability of directing spectra of several different wavelengths or colors through the fluid, one may conduct a fairly complete analysis.
The fluid or fluids under consideration are placed in specialized test tubes called cuvettes. The cuvette typically has a square or rectangular cross-section where at least two opposing sides are prefectly or nearly perfectly parallel. The parallel relationship is important for minimizing diffraction of a visible light beam as it passes through the cuvette.
In one known arrangement of a chemical analyzer, several cuvettes are placed together in a line on a platform. A light source is arranged to be passed through each cuvette serially by moving either the light source or the row of cuvettes. A detector is placed on the other side of the cuvettes, in line with the optical path of the light beam emanating from the light source. Finally, a filter which permits only a narrow bandwidth spectrum of visible light to pass is placed in the optical path of the light source between the source and the cuvettes. One cuvette may be left empty to serve as the reference standard.
With the arrangement described immediately above, one is limited to performing a single test on the cuvettes in a batch mode. If one wishes to perform another test on the fluids, a second batch of cuvettes must be assembled.
OBJECTS OF THE INVENTION
It is an object of the invention to provide a chemical analyzer capable of performing more than one analysis on a single group of test samples.
It is a further object of the invention to provide a chemical analyzer capable of performing tests in batch, random access, and profile modes.
It is a further object of the invention to provide a chemical analyzer which is programmable.
It is a further object of the invention to provide an improved cuvette for use with the analyzer according to the invention.
SUMMARY OF THE INVENTION
These objects as well as others not enumerated here are achieved by the invention, one embodiment of which may include a rotatable sample holding means having at least two sample retaining means, a light source, a narrow bandwidth filter, and a light detector. These components are arranged such that the filter and the rotatable sample holder are located in the optical path of the light generated by the light sourcre. Thus, in one configuration, the light leaves the light source, passes through the filter the sample retaining means, and is ultimately received by the light detector. The output of the light detector is provided to a computer for calculation of the degree of absorbance.
A further feature of the invention is an improved cuvette having an integral reservoir for the reagent. In an alternative embodiment, the cuvette is provided with a detachable reservoir.
BRIEF DESCRIPTION OF THE DRAWINGS
A more complete understanding of the present invention, as well as other objects and advantages thereof not enumerated, will become apparent upon consideration of the following detailed description, especially when considered in light of the accompanying drawings wherein:
FIG. 1 is schematic diagram of the invention;
FIG. 2 is a detailed top view of the invention;
FIG. 3 is a block schematic diagram of the control system for the invention; and
FIG. 4 is a cross-sectional diagram of the cuvette according to the invention.
DETAILED DESCRIPTION OF THE INVENTION
The structure and operation of the chemical analyzer can be best explained by reference to FIG. 1. The sample rotor 10 provides a rotating platform for the cuvettes 12 which contain the fluids under test. The sample rotor 10 is driven by the drive motor and tachometer 14. On the periphery of the sample rotor 10 are two Peltier units 16 and 18 for maintaining the desired temperature level of the samples in the cuvettes 12. At the center of the sample rotor 10 is a photomultiplier tube 20, which serves to detect unabsorbed light passing through the cuvette 12, as will be explained later. Finally, there is a detector optical slit 22 positioned adjacent to the photomultiplier tube 20.
In order to conduct the photometric analysis, it is necessary to generate light. This is done by the light source or lamp 24. The imaginary line intersecting the lamp 24 and the photomultiplier tube 20, designated by reference numeral 26, represents the optical path of the chemical analyzer system.
A second optical slit 28 is positioned in the optical path 26 adjacent the lamp 24. Following the optical slit 28 is a chopper 30 which is driven by the chopper drive motor 32. The next element along the optical path 26 is the optical filter barrel 34, which contains several narrow bandwidth interference filter elements 36. The filter drive motor 38 turns the optical filter barrel 34, positioning it at the desired narrow bandwidth interference filter element 36. The remaining component in the optical path 26 is a third optical slit 40 positioned between the optical filter barrel 34 and the sample rotor 10.
Referring now to FIG. 2, the optical/rotor unit according to the present invention is disclosed in a top view and designated generally by the reference numeral 42. Several of the elements discussed in connection with FIG. 1 can be seen in FIG. 2. For instance, at the approximate center of the optical/rotor unit 42 is the sample rotor 10. At its periphery are Peltier units 16 and 18. To the lower left of the sample rotor 10 is the rotor drive motor and tachometer 14. Lamp 24 is supported by a lamp-holding bracket 44. Approximately adjacent to the lamp 24 is the optical slit 28 which is attached to a left outer frame member 46. The chopper drive motor 32 is also attached to the left outer frame member 46. A chopper drive shaft 48 extends through the left outer frame number 46 to the chopper 30 which is rigidly fixed to the shaft the 48. Immediately adjacent to the chopper 30 is the optical filter barrel 34. The optical filter barrel 34 is driven and positioned by the filter drive 38 which is affixed to an inner frame member 50. The actual position of the optical filter barrel 4 is detected through a filter barrel potentiometer 52, which is mounted on the inner frame member 50 and provides rotational support for the optical filter barrel 34.
The Peltier units 16 and 18 are provided with heat sinks 54 and 56, respectively. Heat sink 54 is attached to the inner frame member 50 on one side and to a right outer frame member 58 on the other side. Heat sink 56 spans between the left outer frame member 46 and the right outer frame member 58.
Power for the lamp 24, the chopper drive motor 32, the filter barrel drive 38, and the sample rotor drive motor 14, as well as the input and output for the photomultiplier tube 20 is provided by a cable and connector assembly 60 which is partially terminated at an optical sensor printed circuit board 62. Finally, mechanical drive power from the sample rotor drive motor 14 is provided to the sample rotor 10 through an idle gear 64. The cable and connector assembly 60 is also partially terminated at a lamp connector 66 which attaches to the lamp 24 at the lamp-holding bracket 44. Other terminations are at the chopper drive motor 32, the filter barrel potentiometer 52, Peltier units 16 and 18, and the rotor drive motor and tachometer 14.
The output of the photomultiplier tube 20 is connected to the optical sensor printed circuit board 62, the output of which is provided to a computer. The interconnections between the chemical analyzer and the computer can be best explained by referring to FIG. 3. Communication to and from the computer 68 by the oprator is achieved through a keyboard 70 and an output peripheral such as a printer of display 72. In accordance with instructions stored in the memory of the computer 68, positioning commands are provided to the filter barrel drive 38 and the rotor drive 14. The computer also provides signals to the Peltier units through temperature control unit 74. Finally, test data is derived from the optical/rotor unit 42 from the output of the photomultiplier tube 20 (FIG. 1) which is processed through the optical detector 76, which partially comprises the optical sensor printed circuit board 62. This signal in turn is sent to the computer 68 for processing in accordance with instructions in memory, ultimately yielding the test results.
A wide variety of tests may be performed with the invention using procedures well knonw in the art. Computer control offers the flexibility of providing testing capability in batch, random access, and profile modes.
The design of the cuvette can be best described by reference to FIG. 4, which illustrates the cuvette 78 in cross-section. As is standard with cuvettes, the cuvette 78 has at least two opposing walls which are parallel with respect to each other. This is most easily achieved with a structure having a square or rectangular cross-section. Two arrangements for storing the sample or reagent prior to mixing are provided. The first, integral with the wall 80 of the cuvette 78, is a reservoir 82 having an inwardly slanting wall 84. With this configuration, the sample or reagent 86 is added directly through the opening or mouth 88 of the curvette 78. The other component 100 is placed in the bottom of the curvette 78.
In an alternative arrangement, a spoon assembly 90 clips on the cuvette 78. The spoon assembly 90 has a spoon 92 which is attached to a handle 94. At the other end of the handle 94 is a hook 96 which slips over the edge 98 of the wall 80 of the cuvette 78. As with the integral reservoir configuration, the reagent or sample 86 is deposited in the spoon 92 and the second component 100 is placed in the bottom of the cuvette 78.
Just prior to commencing a test, the samples or fluids in the cuvettes 78 are mixed. This may be done off-line, or on-line in the photometer unit, using well known apparatus. To mix the samples, vibration can be imparted to the cuvettes 78, creating a vortex. By using cuvettes having sample holding reservoirs, one can preload the samples or reagents into a series of cuvettes, mix the chemical components, and have all reactions commence simultaneously. This will reduce error due to non-uniform starting times for cuvette reactions.
While there has been described what is believed to be the preferred embodiment of the invention, those skilled in the art will recognize that other and further modifications may be made thereto without departing from the spirit of the invention, and it is intended to claim all such embodiments that fall within the true scope of the invention. | The ability to provide a random assortment of chemical analyses is provided by an improved photometric analyzer system. The analyzer has a rotary sample holding means which periodically indexes to place a different cuvette in the optical path of the photometer. An improved cuvette is provided which permits preloading of the samples and reagents without mixing. | 6 |
CROSS-REFERENCE TO RELATED APPLICATION(S)
The present application is a continuation patent application of a U.S. patent application Ser. No. 13/663,710 filed on Oct. 30, 2012, which in turn itself is a divisional application of U.S. patent application Ser. No. 12/013,813 filed on Jan. 14, 2008 and now a U.S. Pat. No. 8,639,788, which in turn itself is a divisional application of U.S. patent application Ser. No. 10/713,905 filed on Aug. 12, 2002, converted from provisional application 60/402,626 and now a U.S. Pat. No. 7,379,990. The application Ser. No. 10/713,905 has also referenced provisional application No. 60/401,238. All above applications are herein incorporated by references in their entireties for all purpose.
FIELD OF THE INVENTION
The present invention generally relates to computer communications network. More specifically, the present invention relates to web based data storage systems.
BACKGROUND OF THE INVENTION
Today's corporate IT professionals typically face many challenges to handle the ever increasing information and data. To handle large amount of data, many organizations expand their storage capacity by employing manage storage systems locally in order to maintaining their normal business operating. A conventional approach is to use IP based network attached storage (“NAS”), which effectively provides data storage and services for end users. Moreover, at the enterprise level, the majority storage systems are directly attached or connected to server(s) or host(s) as shown in FIG. 7 . These server(s) and/or host(s) are typically access to raw block data devices through conventional communication connection media, such as traditional IDE, SCSI, Fibre Channel, or Ethernet.
The server, which is directly attached to a storage system as illustrated in FIG. 7 typically has many drawbacks, which are described as following:
a typical conventional storage management system is only capable of handling 4 TB (terabytes) of data, which is usually not good enough to meet the demands for more storage capacity in an enterprise environment;
The most of servers, which are directly attached to storage systems, have problems for further expanding their storage capacity. For example, it may require to purchase new servers in order to increase storage capacity;
The storage being attached to a server can only be accessed by the attached server and can not be shared by other servers even if server's storage availability is not evenly distributed across all servers within a organization;
Each attached storage system has to be managed separately and this is a nightmare for IT professionals;
With the attached storage system, the backup/restore has to go through the data network, this will tax or reduce the network performance;
A typical SCSI connection only allows a 12-meter distance for data accessing with 15 storage devices. Similarly, Fibre Channel is limited to 10 kilometers communication distance. Distance limitation effectively prevents them from being the best choice for disaster recovery of the storage system; and
The Fiber Channel based storage system cannot handle well for the interoperability. Also, Fibre Channel based storage system is expensive to build and to maintain.
FIG. 8 shows a conventional type of virtual SAN, which is in-band controlled and accessed with which the data path from hosts ( 1 of FIG. 8 ) to the SAN units ( 4 of FIG. 8 ) going through virtual SAN control management station ( 2 of FIG. 8 ). It is not efficient in term of accessing the data by the hosts because the virtual SAN control management station can easily be a performance bottleneck. Similarly, the scalability of this type of virtual SAN is poor.
SUMMARY
With rapid development of high speed communication technology, the problems mentioned above can be solved by an IP based out-band accessed distributed virtual SAN infrastructure illustrated in FIG. 1 of present invention. In referencing to the FIG. 1 , each host 1 can directly access IP based SAN units 4 without going through control management station (“control system”) 3 . The IP based out-band accessed distributed virtual SAN infrastructure actually represents an example of central controlled distributed scalable virtual machine system (CCDSVM) illustrated in FIG. 9 . Wherein, each system units actually is a SAN unit 4 , specifically is an IP based SAN unit.
With this invention, in one embodiment, each SAN unit 4 can be accessed by one or more hosts 1 and each host 1 can access one or more SAN units 4 as illustrated in FIG. 6 . In addition, the storage access goes directly through communication link 2 between hosts 1 and SAN units 4 without involvement of the control management station 3 . Further, a new SAN unit 4 can be dynamically added at any time without interrupting current data access of SAN units 4 by hosts 1 . In addition, all SAN units are centrally controlled, monitored, and managed by a control management station 3 through a management console 10 of a console system 14 . The control management station 3 may also accept storage volume/partition requests from each host 1 , and assign the matched volumes/partitions of the SAN units 4 to the requested hosts. Therefore, each host 1 could directly access the right volumes/partitions of assigned SAN units without going through the control management station 3 again.
This invention will become understood with reference to the following description, claims, and accompanying figures.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will be understood more fully from the detailed description given below and from the accompanying drawings of various embodiments of the invention, which, however, should not be taken to limit the invention to the specific embodiments, but are for explanation and understanding only.
FIG. 1 illustrates a distributed virtual storage area of network (“SAN”) infrastructure in accordance with one embodiment of the present invention;
FIG. 2 illustrates actual components of Distributed Virtual SAN in accordance with one embodiment of the present invention;
FIG. 3 illustrates Virtual SAN automatic configuration protocol in accordance with one embodiment of the present invention;
FIG. 4 illustrates packet format for a Virtual SAN auto configuration protocol in accordance with one embodiment of the present invention;
FIG. 5 illustrates an example of storage volume information of an IP SAN Unit in accordance with one embodiment of the present invention;
FIG. 6 illustrates a hypothetical example of storage volume requests and assignment in accordance with one embodiment of the present invention;
FIG. 7 is a conventional Direct Attached Storage System;
FIG. 8 is an in-bound accessed virtual storage system;
FIG. 9 illustrates a simplified diagram of a central controlled distributed scalable virtual machine system in accordance with one embodiment of the present invention; and
FIG. 10 illustrates a simplified diagram of disaster recovery scheme of a distributed virtual san infrastructure in accordance with one embodiment of the present invention.
DETAILED DESCRIPTION
The following terms are used through out this patent application to describe the present invention. A central controlled distributed scalable virtual machine (“CCDSVM”) system allows a control management station to control a group of computing systems and to provide distributed services to client systems across the Intranet, Internet, and/or LAN environment. Storage media includes magnetic hard disk drives, solid state disk drives, optical storage drive, and memory card, etc. Storage connection and control media may include controller of IDE, SCSI, Fibre optical, Ethernet, USB, or wireless media, and/or other related cables etc. Each controller of storage media such as Raid, IDE, or SCSI controller may control multiple storage media drivers in a computing system. Storage system includes one or more storage media devices, storage connections, and/or storage media controllers. Storage system also contains related software modules for delivering storage services.
Storage area network (“SAN”) is a storage system that is capable of providing block data services to various computer devices through storage connection media, such as Fibre-optical cable, Ethernet cable or other media by deploying Internet Protocol (“IP”) based or non-IP based protocol. The non-IP based protocol, in one example, includes Fibre-Channel protocol. IP SAN uses IP based protocols to provide storage raw block data services. All discussions of the SAN in this invention are within the scope of a model of central controlled distributed scalable virtual machine (“CCDSVM”).
DNS stands for domain name service for the Internet network. DNS is an Internet software infrastructure and is capable of identifying network addresses and name for computing systems. For example, the network addresses may be used to communicate with the peer systems of a computing device. A Simple Network Management Protocol (“SNMP”) is a standard Internet protocol. A SNMP trap is a user datagram protocol (“UDP”) packet, which may be used to send by a SNMP daemon on a SNMP agent system to a SNMP network management station via network links.
FIG. 1 shows an example of a simplified block diagram of IP based out-band accessed distributed virtual SAN infrastructure. The distributed virtual SAN infrastructure includes a plurality of hosts 1 , network infrastructures 2 , a control management station 3 , a virtual storage service pool 11 of a plurality of IP SAN units 4 , and a management console 10 . In one embodiment, each of the hosts 1 contains service software modules 9 . The service software modules 9 are configured to communicate with a control management software module 7 of the control management station 3 for obtaining information of a specific one of the IP SAN units 4 . The service software modules 9 also operable to communicate with service software modules 6 of each of the IP SAN units 4 for access to block data provided by the each of the SAN units 4 . For example, each of the hosts 1 can create a local file system or create a local database by requesting and using raw block data of a storage volume provided by one of the SAN units 4 . The service software modules 9 can be coded or implemented with any suitable programming languages such as C, C++, Java or others. The service software modules 9 may also use any suitable protocols such as IP based or non-IP based protocols.
The host 1 , in one embodiment, could be a server, a desktop, a laptop PC, or a communication device etc., which needs to access block data storage. The spare host 12 represents a part of recovery scheme that could be implemented in a CCDSVM environment.
Network infrastructure 2 comprises many kind of communication links. The network infrastructure 2 could be a storage backbone of an enterprise, a department LAN, a corporate intranet, an Internet infrastructure or others. In one embodiment, network infrastructure 2 includes switches, routers, gateways, cables (Ethernet, optical Fibre), wireless communication media, or others. The network infrastructure 2 provides data path between the hosts 1 , the distribute control management station 3 , and the SAN Units 4 . The network infrastructure 2 also includes software infrastructure such as DNS or DHCP for facilitating a computing device to identifying a designated addresses of a designated computing device for sending or receiving data within a network domain or in a cross-domain network environment.
It should be noted that DNS and/or other Internet address identification mechanism may be used when a message or data stream is sent from a system A to a system B.
The control management station 3 includes distributing control management software modules 7 and console support software modules 8 . To support web-based console, it requires the web server software 15 . The distribute control management software modules 7 communicate with service modules 6 of each of the IP SAN units 4 and are operable to retrieve storage information for constructing a virtual SAN storage service pool 11 . The communication between the distributed control management software modules 7 and the service modules 6 of each of the IP SAN units 4 is further configured to monitor each of the IP SAN units, and to perform various system operations, which include storage configuration and partitioning etc. The control management software modules 7 also communicate with service software modules 9 of each of the hosts 1 for distributing storage volumes to each of the hosts 1 upon a request. The distribute control management software modules 7 can be implemented with any suitable programming languages such as C, C++, Java, XML, etc. The communication protocols between control management station 3 and IP SAN units 4 could be any suitable IP based protocols. The communication between control management station 3 and hosts 1 can be any suitable IP base or non-IP based protocols.
The console support software modules 8 employ inter-process communication mechanism to obtain information relating to each of the IP SAN units ( 4 ) from the distributed control management software modules 7 . The console support software modules 8 further provide information to web server software 15 through the inter-process communication mechanism. The console support software modules 8 can be implemented with any suitable programming languages such as C, C++, Java, XML, etc.
The web server software 15 communicates with management console software 10 of the console host 14 through web protocol such as HTTP. The web server software 15 is configured to provide end-user a centralized storage management capability within the entire distributed virtual SAN infrastructure cross network. The web server software 15 could be commercially available software or other proprietary software.
To simplify foregoing discussion, the communication path mentioned above will be simply referred to as the console support software modules 8 communicate (send/receive data) with the management console 10 of the console host 14 without further mentioning the role and function of web server software 15 of the distribute control management station 3 .
In addition, to support non-web based console, the web server software 15 on the control management station 3 is often not required. In this case, the console support software modules 8 could communicate with the management console software 10 with a suitable protocol other than a web protocol such as HTTP.
The virtual storage pool 11 includes a plurality of IP SAN units 4 , wherein each of the IP SAN units further includes service modules 6 and is configured with storage media, storage communications and control media. The storage media of each of the IP SAN units 4 , for example a disk drives, is configured to have one or more logical volumes. Each storage volume, in one embodiment, is further partitioned into several partitions as shown in FIG. 5 . Each of the IP SAN units 4 further comprises block data service and other service software modules 6 . The service software modules 6 is configured to communicate with distribute control management station 3 for providing storage information and for performing storage operations. The service software modules 6 , in another embodiment, are further configured to communicate with service software modules 9 of each of the hosts 1 for providing block data services to the each of the hosts 1 . The service software modules 6 can be implemented by any suitable programming languages such as C, C++, Java, etc and they may employ any suitable IP based communication protocols.
In one embodiment, the control management station 3 organizes the IP SAN units 4 to form the virtual storage service pool 11 . The virtual storage pool 11 may contain information relating to IP addresses, the storage volumes of the block data, their addresses and sizes for each of the IP SAN units 4 . A spare IP SAN unit 13 in one embodiment represents a part of recovery scheme used in the centrally controlled distributed scalable virtual machine environment.
A Fibre channel to IP gateway 5 in one embodiment is a component that is configured to provide translation between Fibre Channel based protocol and IP based protocol so that any Fibre Channel based SAN unit in the distributed virtual SAN infrastructure will appear as if a IP based SAN unit to the rest of the distributed virtual SAN infrastructure illustrated in FIG. 1 .
Fibre channel SAN unit is similar to an IP SAN unit 4 except it uses Fibre Channel storage controller, which uses Fibre Channel protocol to communicate with other parties over a fiber channel network. In addition, any Fibre Channel SAN unit appears as an IP based SAN unit to the distributed virtual SAN once it connects to the Fibre Channel to IP gateway 5 . Therefore, to simplify the foregoing discussion, a fibre channel SAN unit will be treated similarly as an IP SAN unit in all of following discussion without additional comments.
The management console 10 of the console host 14 , which has been described in pending patent application of “Concurrent Web Based Multi-Task Support for Control Management System” by the same author and is incorporated herein by reference in its entirety. The management console 10 could be a commercially available web browser or a proprietary Web browser. A web browser 10 is able to communicate with web server software 15 on the control management station 3 through a web protocol such as HTTP. The Web browser 10 could be implemented by any suitable programming languages such as C, C++, Java, XML, etc. In addition, the management console software module 10 could be a networked software module other than a web browser software. In this case, any other suitable network protocols can be used instead of using web protocol such as HTTP.
To simplify the foregoing discussion, the communication path between the management console 10 of the console host 14 and the console support software modules 8 of the control management station 3 will not further mention the role or function of the web server software module 15 in this invention.
From the management console 10 , multiple concurrent system operations and tasks can be performed by user for the entire distributed virtual SAN infrastructure. There are may be one or more management consoles of the distributed virtual SAN infrastructure anywhere across the communication network.
FIG. 2 illustrates a portion of FIG. 1 relating to an actual virtual SAN. The plurality of SAN units 4 form a virtual storage service pool 11 . The virtual storage service pool 11 may contain information of each of the IP SAN units' IP address, the storage volumes configured on each storage device and their sizes, etc.
FIG. 3 shows a protocol for a virtual SAN automatic configuration as well as shutting down a SAN unit 4 in the virtual storage service pool 11 of virtual SAN. The packet format used with this protocol is described in FIG. 4 .
FIG. 4 shows the message format, which is used by “Virtual SAN Automatic Configuration Protocol” for sending and receiving a packet, wherein the source and destination IP address are included that means the storage communication can be independent of naming identification services such as DNS or others in one embodiment.
FIG. 5 illustrates storage layout in an IP SAN unit 4 , wherein the storage layout may be further divided into multiple volumes and each of the volumes may be further divided into multiple partitions. Each of the volumes is referred as a logical storage unit in this discussion and it might contain multiple pieces of storage spaces from multiple storage hardware media.
FIG. 6 is a simplified and a portion of FIG. 1 , which shows a hypothetical example of how hosts are configured access to the storage volume of IP SAN units. Where each of the IP SAN units 4 is a portion of virtual storage pool 11 and each of the hosts is substantially the same as presented in FIG. 1 .
FIG. 8 is a block diagram illustrating an In-Band Accessed Virtual SAN. FIG. 8 shows another type of virtual SAN, wherein, the actual storage data path from hosts to IP SAN units has to go through control management station.
FIG. 9 is a Simplified diagram of central controlled distributed scalable virtual machine. With this invention, the systems in a CCDSVM can be flexibly organized into multiple different service pools according to their functionalities. For example, multiple IP SAN units can form a virtual SAN storage pool. The hosts of the CCDSVM could form other service pools to provide services other than storage services such as video services, security monitor services, and all other services provided across the world wide web.
FIG. 10 is a simplified diagram of disaster recovery scheme of the distributed virtual SAN infrastructure, which includes one virtual storage service pool of a plurality of IP SAN units and one service pool of a plurality of hosts. For example, host 1 ( 1 ) accessible to IP SAN units 1 and 2 while host 1 ( 3 ) accessible to IP SAN units 4 and 5 . Also, IP SAN units 4 ( 1 ) and ( 2 ) are mirrored so that they have kept the same copy of data for host 1 ( 1 ). The same to be true for IP SAN units 4 ( 4 ) and ( 5 ) with host 1 ( 3 ). In addition, IP SAN unit 4 ( 3 ) may be a spare unit and the host 1 ( 2 ) could be a spare host for providing fault replacement in case a fault occurred.
FIG. 1 shows a simplified diagram of a distributed virtual SAN infrastructure according to the present invention. With the distributed virtual SAN infrastructure, the distributed virtual SAN storage service pool 11 comprises one or more SAN units 4 , which may be further connected to a distribute control management station 3 . The SAN units 4 can be accessed by one or more hosts 1 via the network infrastructure 2 . The entire distributed virtual SAN infrastructure can be operated through a management console 10 .
The virtual storage volume service pool 11 of the distributed virtual SAN infrastructure can be initiated and updated when each of the IP SAN units 4 is booted and brought to online. The virtual storage volume service pool 11 , in one embodiment, is updated when at least one of IP SAN units is powered down or removed from the web environment. FIG. 3 shows the distributed Virtual SAN Automatic Configuration Protocol, which leads to the success of constructing the virtual storage service pool 11 of the distributed virtual SAN infrastructure according to this invention. The following steps are for automatic building the storage volume service pool of the distributed virtual SAN based on the protocol illustrated in FIG. 3 . The protocol described bellow could be IP based protocol such as SNMP, or a much simple UDP based protocol as illustrated in FIG. 4 , or any other suitable protocols.
When any one of the IP SAN units 4 such as unit (n) brought up online, SAN service modules 6 of the one of IP SAN unit 4 sends out a “SAN unit (n) startup” packet, as illustrated in FIG. 4 , to the distribute control management station 3 . The “SAN unit (n) startup” packet could be a simple user defined UDP packet indicating information about a storage unit with a number “n” just being powered up. The message carried by the packet could also be a SNMP trap of cold start packet, or link-up packet 4 or other short packet/message of any suitable IP protocols.
When the distribute control management modules 7 of the distribute control management station 3 detects and receives the IP SAN unit (n)'s message, it stores the IP SAN unit (n)'s information, such as stored into a IP SAN unit information list for the virtual storage service pool 11 .
After storing information of the IP SAN unit, the control management modules 7 on the distribute control management station 3 sends back a “need SAN unit (n)'s storage info” packet to the IP SAN unit (n) 4 .
When the SAN service modules 6 of the IP SAN unit (n) 4 receive the packet of “need SAN unit (n)'s storage info”, the SAN service modules 6 obtain the storage information of the IP SAN units (n) 4 , which may include the number of storage volumes, each of the storage volumes' starting address (logical block address, LBA), length, and the end address (logical block address, LBA). The SAN service modules 6 then send back a packet of “unit (n) storage info”, which may include all information obtained, to the control management station 3 .
After receiving the “unit (n) storage info” packet from the IP SAN unit (n) 4 , the distribute control management modules 7 of the distribute control management station 3 update the stored information of the virtual storage service pool 11 with corresponding storage information of the IP SAN unit (n) obtained from the packet.
When the IP SAN unit number (n) is shutting down, the service module 6 of the IP SAN unit number (n) 4 sends a “Unit (n) shutdown” message to the distribute control management station 3 . This shutdown message could be an SNMP trap of link down, or a simple UDP packet as illustrated in FIG. 4 with a message type of system down, or other short packet based on some other protocols.
After automatically detecting and receiving of the “unit (n) shutdown” packet from the IP SAN units number (n) 4 , the distribute control management modules 7 of the distribute control management station 3 update the stored information of the virtual storage service pool 11 for the IP SAN unit (n) 4 , for example, updating and marking the status of the IP SAN unit number (n) as down in a entry of the IP SAN unit information list. In addition, other information may be also required to be updated, for example, updating the total storage capacity of the virtual storage service pool.
After one or more IP SAN units 4 are brought online, the control management station 3 has owned the stored information of the storage volumes and network for each of the IP SAN units 4 in the virtual storage service pool 11 . Therefore, the control management station 3 can control entire virtual SAN infrastructure. For example, the distribution control management station 3 is able to accept block data requests from each of the hosts 1 and distributed storage volumes to each of the hosts 1 based on the request in several steps as illustrated bellow in respect to the FIG. 6 :
First, an exampled host 1 numbered as ( 1 ) sends a request to the control management station 3 for requesting a storage space, such as 80 GB (gigabyte) of a storage volume. Second, the control management station 3 stores information of the host 1 ( 1 ) and searches for availability of the 80 GB of storage volume. The control management station 3 , for example, finds an 80 GB available storage volume being labeled as volume number ( 2 ) in an IP SAN unit 4 numbered as (M). Third, the control management station 3 sends the requested information of the host 1 ( 1 ) to the IP SAN unit 4 (M), wherein the requested information includes the IP address of the host 1 ( 1 ) and the requested storage size. The control management station 3 also sends information of the storage volume ( 2 ) in the IP SAN unit 4 (M) to the host 1 ( 1 ), wherein the information of the storage volume number ( 2 ) includes the IP address of the IP SAN unit 4 (M), the storage volume number and the size, the storage volume's starting address and ending logical address block (LBA). Therefore, all parties of three, namely the control management station 3 and the host 1 ( 1 ) and the IP SAN unit 4 (M) are synchronized for keeping a same mapping of the storage volume assignment information. Fourth, once the host 1 ( 1 ) and the IP SAN unit 4 (M) get each other's information, the host 1 ( 1 ) can directly and independently access the storage volume ( 2 ) of the IP SAN unit 4 (M) immediately and the IP SAN unit 4 (M), in one embodiment, is further configured to perform security checking in light of storage access by the host 1 ( 1 ).
Alternatively, the above described steps for distributing storage volume may also be semi-automatically setup with assisting of admin operations performed via the management console 10 . For example, an administrator via the management console 10 of a console host 14 could manually setup the storage volume ( 2 ) of the IP SAN unit 4 (M) to be exclusively access by the host 1 ( 1 ) as long as the administrator acknowledges that the host 1 ( 1 ) needs such size of storage volume. The administrator can also manual setup the host 1 ( 1 ) with all information needed to access the storage volume ( 2 ) of the IP SAN unit 4 (M). Finally, the host 1 ( 1 ) can access to the storage volume ( 2 ) of the IP SAN unit 4 (M) directly without going through the control management station 3 ).
The present invention also discloses a mechanism of dynamically expanding storage capacity. After the distributed virtual SAN storage pool 11 is initiated and constructed, each of the hosts 1 will be able to access the storage volumes of any one of the IP SAN units 4 in the pool 11 directly without further involvement of the control management station 3 . This will allow the virtual storage service pool 11 of the distributed virtual SAN infrastructure to continue expanding, for example by bring up one or more SAN storage units 4 online, without affecting any one of the hosts 1 to continue access to the assigned storage volumes on any one of the assigned IP SAN units 4 in the virtual storage service pool 11 . This means that it guarantees the distributed virtual SAN storage pool 11 can be dynamically expanded without interrupting normal storage operations and access to the entire distributed virtual SAN storage pool 11 .
The present invention further discloses a technique of system scalability. Once the distributed virtual SAN storage pool 11 is constructed, each of the hosts 1 can access one or more IP SAN units 4 in the virtual storage service pool 11 of the distributed virtual SAN infrastructure whenever each of the hosts 1 sends a request. For example, the host 1 ( 1 ) illustrated in FIG. 6 can access three IP SAN units that numbered as SAN unit 4 ( 1 ), unit ( 2 ), and unit (M) after the host 1 ( 1 ) requests for storage volumes and the control management station 3 grants each of the requests. This effectively provides scalable storage system for the hosts 1 ( 1 ) within distributed virtual SAN infrastructure. Further, the distributed virtual SAN infrastructure provides far better scalability than the in-band accessed virtual SAN as illustrated in FIG. 8 , wherein the scalability of in-band accessed virtual SAN were severely limited by the bottlenecked control management station.
The present invention also discloses a method of storage sharing mechanism. Once the distributed virtual SAN storage pool 11 is constructed, each of the IP SAN units 4 in the virtual storage service pool may be configured with multiple storage volumes in the form of block data for accessed by one or more hosts 1 . Therefore, the hosts ( 1 ) are allowed to share storage volumes on any one of the IP SAN units 4 by granting and assigning each of the hosts to exclusively access one of the storage volumes on the one of the IP SAN units 4 . The FIG. 6 demonstrates such a storage sharing, wherein the IP SAN unit 4 number as ( 2 ) has three volumes, which named volume ( 1 ), volume ( 2 ), and volume ( 3 ). The block data service modules 6 of the IP SAN unit 4 ( 2 ) allows volume ( 1 ) to be accessed exclusively by the host 1 ( 1 ) while volume ( 2 ) to be accessed exclusively by a host 1 ( 2 ).
With in-band accessed virtual SAN as illustrated in FIG. 8 , the control management station could be a performance bottleneck. With distributed virtual SAN of this invention, each of the hosts 1 can directly and independently access to any of the IP SAN units 4 . Therefore, the performance of storage accessing for each of the hosts will not be affected and can match the performance of direct attached storage system as illustrated in FIG. 7 when the high speed network connecting media is deployed in the distributed virtual SAN infrastructure.
The present invention also illustrates a method of a centralized management of distributed virtual SAN. The storage management console 10 of a console host 14 can communicate with the console support software module 8 of a control management station 3 . The storage management console 10 is configured to further receive information relating to all of the IP SAN units 4 from the control management modules 7 of the control management station 3 . Therefore, via the storage management console 10 , admin user can perform centralized management functionality for the entire SAN units 4 in the distributed virtual SAN storage pool 11 , the hosts 1 , and the control management station itself 3 . With web based multiple concurrent tasks controlled by the console support software modules 8 of the control management station 3 , the admin user via the storage management console 10 can perform a full range of system operations and tasks, where each of tasks and operations can be run concurrently within the storage management console 10 for throughout the entire distributed virtual SAN and the hosts 1 . These management tasks include storage configuration, storage volume allocation, de-allocation, and assignment for storage distribution, storage partitioning and repartitioning, and monitoring of storage, network, and other resource usages and activities.
In one embodiment, the present invention discloses a process of disaster recovery capabilities. The use of DNS or an IP address identification mechanism helps this distributed virtual SAN infrastructure to overcome the geometric (region) limitation, and works well in a cross network domain environment or in a single network domain environment. Therefore, any of the IP SAN units 4 or hosts 1 as well as a control management station 3 could be anywhere on the corporate Intranet, department LAN, or Internet. As a result, the present invention can be used for an emergency or a disaster recovery plan because the distributed virtual SAN infrastructure that can go beyond 100 miles as oppose to the traditional 10-kilometer limitation.
In addition, the disaster recovery plan of distributed virtual SAN infrastructure can be flexibly implemented in one embodiment as showing in FIG. 10 . With this recovery plan, the host 1 numbered as ( 1 ) or ( 3 ) can continue to operate even if one of mirrored IP SAN units 4 , which serves the host ( 1 ) or host ( 3 ), failed. Also, a spare IP SAN unit 4 can be used to quickly replace the failed one of the IP SAN units 4 whenever there is a need. On the other hand, the hosts 1 illustrated in FIG. 10 also can be organized into a service pool for providing special services, such as distributing video services, distributed database pool, distributed security monitor services, and all other services provided cross the network or the World Wide Web. Therefore, whenever the host 1 ( 1 ) or ( 3 ) failed, a spare host 2 can quickly take over the host 1 ( 1 ) or the host 1 ( 3 )'s assigned storage in a IP SAN unit 4 and replace the host 1 ( 1 ) or the host 1 ( 3 ) for continue providing services to the end user computing devices.
It should be noted that the storage of any IP SAN unit 4 can be shared and accessed by multiple hosts. To scale storage capacity, a host may be assigned to access multiple volumes capacities from multiple IP SAN units. In one embodiment, the storage access goes directly through communication link between hosts 1 and SAN units 4 , which means that it is an out-band access. An advantage of using the present invention is that it has better performance and scalability than that in-band accessed virtual SAN. Furthermore, the present invention allows the virtual storage pool 11 to expand dynamically through adding more IP SAN units into the storage service pool 11 without interrupting systems operation.
The distributed virtual SAN infrastructure can be managed and monitored from a centralized console 10 . Also, the IP based distributed virtual SAN infrastructure is a new type of central controlled distributed scalable virtual machine (CCDSVM). The software implemented in IP based distributed virtual SAN infrastructure represent a web based operating system model. Furthermore, the methods and principles of automatically building the IP based distributed virtual SAN storage pool can be applied to automatically build service pools for delivering various on-demand services to the end users or clients. | Rapid demanding for storage capacity at internet era requires a much flexible and powerful storage infrastructure. Present invention disclosed a type of storage system based a model of centrally controlled distributed scalable virtual machine. In this model, one or more service pools including virtual storage service pool and application service pools can be automatically created to meet the demands for more storage capacity from various applications. Specially this model provide a solid foundation for distributing storage volumes for supporting storage on-demand and sharing with exceptional management capabilities. In addition, this model provides a flexible fault recovery topology beyond the traditional recovery plan. | 7 |
BACKGROUND OF THE INVENTION
[0001] This invention relates to a tractor with a PTO apparatus having a rear PTO shaft disposed at the rear of a vehicle body and a mid-PTO shaft disposed under the vehicle body.
[0002] A known tractor includes a rear PTO shaft disposed at the rear of a vehicle body, a mid-PTO shaft disposed under the vehicle body, and a PTO mode selecting mechanism for selecting an output state from three output states. The three output states are a state of outputting power only from the rear PTO shaft, a state of outputting power from both the rear PTO shaft and mid-PTO shaft, and a state of outputting power only from the mid-PTO shaft. The tractor further includes a PTO clutch disposed on a power transmission line upstream of the PTO mode selecting mechanism (see Japanese Application “Kokai” No. 5-162551, FIG. 7 , for example).
[0003] The above PTO transmission structure has excellent practical utility for enabling a wide range of operations using the rear PTO shaft and mid-PTO shaft. However, the PTO mode selecting mechanism could be operated inadvertently without disengaging the PTO clutch, thereby abruptly rotating the PTO shafts from stationary state, or abruptly stopping the PTO shafts in rotation. In this way, an excessive force may be applied to meshed gears or splines on the PTO transmission line to damage such components or produce a loud noise.
SUMMARY OF THE INVENTION
[0004] The object of this invention is to solve the above-noted problems. A tractor with a PTO apparatus comprises: a plurality of wheels; a vehicle body supported by said plurality of wheels; an engine supported on said vehicle body; a rear PTO shaft disposed at a rear of said vehicle body for transmitting power from said engine; a mid-PTO shaft disposed under said vehicle body for transmitting power from said engine; a PTO mode selecting device having a first position for transmitting power only to said rear PTO shaft, a second position for transmitting power to both said rear PTO shaft and said mid-PTO shaft, and a third position for transmitting power only to said mid-PTO shaft; a PTO clutch disposed on a transmission line upstream of said PTO mode selecting device and switchable between an engaged position and a disengaged position; and a restricting mechanism for preventing a change operation of said PTO mode selecting device when said PTO clutch is in the engaged position, and permitting the change operation of said PTO mode selecting device when said PTO clutch is in the disengaged position.
[0005] According to the above construction, the PTO mode selecting device is switchable only when the PTO clutch disposed on the transmission line upstream of the PTO mode selecting device is in the disengaged position. This feature precludes the possibility of abruptly rotating the PTO shafts from stationary state or abruptly stopping the PTO shafts in rotation.
[0006] Thus, the apparatus according to this invention contributes to improvement in the durability and operability of the PTO transmission system.
[0007] The disclosures of Japanese Patent Applications 2004-300336 filed on Oct. 14, 2004 and 2004-188316 filed on Jun. 24, 2004 are incorporated by reference.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] FIG. 1 is a side elevation of a tractor;
[0009] FIG. 2 is a side view in vertical section of a front wheel transmission structure;
[0010] FIG. 3 is a side view in vertical section of a transmission structure;
[0011] FIG. 4 is a schematic view showing gear trains of the transmission structure;
[0012] FIG. 5 is a side view in vertical section of a front wheel change speed mechanism in a standard four wheel drive mode;
[0013] FIG. 6 is a side view in vertical section of the front wheel change speed mechanism in a front wheel accelerating drive mode;
[0014] FIG. 7 is a hydraulic circuit diagram;
[0015] FIG. 8 is a side view in vertical section of a PTO mode selecting device;
[0016] FIG. 9 is a side view in vertical section of the PTO mode selecting device;
[0017] FIG. 10 is a side view in vertical section of the PTO mode selecting device;
[0018] FIG. 11 is a side view showing a control structure for controlling the PTO mode selecting device;
[0019] FIG. 12 is a front view showing the control structure for controlling the PTO mode selecting device;
[0020] FIG. 13 is a plan view of a rear portion of a vehicle body;
[0021] FIG. 14 is a plan view of a lever guide;
[0022] FIG. 15 is a sectional view showing a proximal end of a position control lever;
[0023] FIG. 16 is a view showing characteristics of a plate spring;
[0024] FIG. 17 is a plan view showing a lever guide in another embodiment;
[0025] FIG. 18 is a side view showing a lever guide for a PTO system according to this invention;
[0026] FIG. 19 is a plan view showing the lever guide of the PTO system according to this invention; and
[0027] FIG. 20 is a perspective view showing components of a restricting device according to this invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0028] Preferred embodiments of this invention will be described hereinafter with reference to the drawings.
[0029] FIG. 1 shows a side elevation of a tractor according to this invention. The tractor includes a clutch housing 2 directly connected to the back of an engine 1 , a housing frame 4 of sheet metal structure, a main transmission 12 in the form of a hydrostatic stepless transmission (HST), a transmission case 3 and a differential case 5 . These components are successively connected in tandem to constitute a vehicle body. The differential case 5 rotatably supports right and left rear wheels 6 , and has a rear PTO shaft 7 projecting rearward. Right and left front wheels 8 are dirigibly supported by a front axle case 9 attached for rolling motion to a lower position of a front frame 10 connected to the engine 1 .
[0030] Next, the structure of a transmission system of this tractor will be described. As shown in FIG. 2 , the clutch housing 2 has a main clutch C 1 of the single plate, dry type mounted in an upper portion thereof. As shown in FIG. 3 , the main transmission 12 includes, arranged in upper and lower positions thereof, a variable displacement pump P of the axial plunger type and a fixed displacement motor M of the axial plunger type. A main output shaft 14 projecting rearward from the clutch housing 2 is interlocked, through a main transmission shaft 15 , to an input shaft 13 projecting forward from the upper position of the main transmission 12 .
[0031] A well-known structure is employed for the main transmission 12 for driving an output shaft 16 of the motor M at steplessly variable speeds forward or backward by varying a swash plate angle of the pump P to change the amount and direction of pressure oil discharge. Thus, the main transmission 12 is operable by a change pedal, not shown, disposed in a right-hand position on a driving platform, to effect stepless speed changing and backward and forward switching from a zero speed start.
[0032] The transmission case 3 is open at the front and rear ends, and has an intermediate partition wall 3 a located in a fore and aft intermediate position thereof to divide its interior into a front portion and a rear portion. A transmission shaft 17 of the propelling system supported by the intermediate partition wall 3 a and a front wall 5 a of the differential case 5 is coaxially coupled to the output shaft 16 of the motor M. In the rear portion of the transmission case 3 , a bevel pinion shaft 18 acting as a final transmission shaft is supported by the intermediate partition wall 3 a and the front wall 5 a of the differential case 5 . An auxiliary change speed gear mechanism 19 of the propelling system is mounted between the transmission shaft 17 and the bevel pinion shaft 18 . The auxiliary change speed gear mechanism 19 has a shift gear G 1 splined to the transmission shaft 17 to be shiftable to rotate the bevel pinion shafts 18 at three speeds. Thus, the right and left rear wheels 6 are driven at variable speeds through a differential mechanism D meshed with a bevel pinion gear Gp.
[0033] Specifically, the transmission shaft 17 has a large diameter loose fit gear G 2 mounted on a forward part thereof, and a small diameter loose fit gear G 3 mounted on a rearward part thereof. The bevel pinion shaft 18 has a small diameter gear G 4 fixed thereto and in constant mesh with the large diameter loose fit gear G 2 , and a large diameter gear G 5 fixed thereto and in constant mesh with the small diameter loose fit gear G 3 . The bevel pinion shaft 18 further includes an intermediate diameter gear G 6 fixed thereto to be meshable directly with the shift gear G 1 . When the shift gear G 1 is shifted rearward to couple a boss portion thereof to a boss portion of the small diameter loose fit gear G 3 , a “low speed” is provided by the gear ratio between the small diameter loose fit gear G 3 and large diameter gear G 5 . When the shift gear G 1 is shifted to a fore and aft intermediate position to mesh directly with the intermediate gear G 6 , an “intermediate speed” is provided by the gear ratio between the shift gear G 1 and intermediate gear G 6 . When the shift gear G 1 is shifted forward to couple a boss portion thereof to a boss portion of the large diameter loose fit gear G 2 , a “high speed” is provided by the gear ratio between the large diameter loose fit gear G 2 and small diameter gear G 4 .
[0034] As described above, the bevel pinion shaft 18 is hydraulically and steplessly changed to different forward or backward speeds, and changed to three speeds by the auxiliary change speed gear mechanism 19 . The bevel pinion shaft 18 has an output gear G 7 fixed to a forward end thereof for power transmission to the front wheels 8 . Further, a front wheel driving transmission shaft 20 extends through, and is supported by, the intermediate partition wall 3 a and the main transmission 12 . The front wheel driving transmission shaft 20 has a shift gear G 8 splined to a rear end region thereof. This shift gear G 8 is shiftable forward into mesh with the output gear G 7 on the bevel pinion shaft 18 . This provides a four wheel drive state in which power for front wheel drive is taken from the front wheel driving transmission shaft 20 at a speed synchronized with a rear wheel driving speed. When the shift gear G 8 is shifted rearward to disengage from the output gear G 7 , the front wheels 8 are no longer driven and a rear, two wheel driving state is provided to drive only the rear wheels 6 .
[0035] On the other hand, as shown in FIG. 2 , the clutch housing 2 includes a dry type clutch chamber “a” for accommodating the main clutch C 1 , and a wet type (oil bath lubrication type) change speed chamber “b” isolated from the chamber “a”. The change speed chamber “b” houses a front wheel change speed mechanism 21 for receiving the front wheel driving power taken forward from the front wheel driving transmission shaft 20 . The front wheel change speed mechanism 21 includes an input shaft 23 coaxially coupled to the front wheel driving transmission shaft 20 through an intermediate shaft 22 , and a transmission shaft 24 extending parallel to the input shaft 23 . The transmission shaft 24 has a shift clutch C 2 mounted thereon and operable to rotate the transmission shaft 24 at two, high and low speeds. The power is then transmitted through gears to a front wheel drive shaft 26 disposed at a lower end of the clutch housing 2 . The power taken forward from the front wheel drive shaft 26 at the two, high and low speeds is transmitted to the front axle case 9 .
[0036] The input shaft 23 has a large diameter gear G 9 and a small diameter gear G 10 . The transmission shaft 24 has a small diameter idle gear G 11 and a large diameter idle gear G 12 in constant mesh with these gears G 9 and G 10 . The shift clutch C 2 mounted on the transmission shaft 24 , as shown in FIG. 5 , includes a frictional transmission portion 29 of the multi-disk type disposed between a clutch drum 27 fixed to the transmission shaft 24 and a splined boss 28 formed integral with the small diameter idle gear G 11 . The clutch drum 27 contains a piston member 30 displaceable by pressure oil supplied and drained through an oil passage formed in the transmission shaft 24 and by a spring 31 mounted in the clutch drum 27 , thereby placing the friction transmission portion 29 in a pressure contact state and canceling the pressure contact state to engage and disengage the clutch C 2 .
[0037] A shift member 32 is shiftably mounted on a boss portion of the clutch drum 27 , and rigidly connected to the piston member 30 through connecting pins 33 penetrating the clutch drum 27 . Thus, the shift member 32 is shifted with movement of the piston member 30 . When the pressure oil supply is stopped, as shown in FIG. 5 , the piston member 30 is displaced leftward in the figure by the inner spring 31 , to place the shift clutch C 2 in “off” state. At the same time, the shift member 32 connected to the piston member 30 meshes with a side of the large diameter idle gear G 12 . Power is transmitted from the input shaft 23 to the transmission shaft 24 at reduced speed through the small diameter gear G 10 , large diameter idle gear G 12 , shift member 32 and clutch drum 27 . Then, the power is taken from the forward end of the transmission shaft 24 , and transmitted to the front axle case 9 through the front wheel driving shaft 26 . In this case, the front wheels 8 are driven at a peripheral velocity equivalent to (or slightly faster than) a rear wheel peripheral velocity, thereby to provide a standard four wheel drive mode.
[0038] When pressure oil is supplied, as shown in FIG. 6 , the piston member 30 is moved against the force of inner spring 31 , rightward in the figure, to place the friction transmission portion 29 in the pressure contact state, and thus to place the shift clutch C 2 in “on” state. At the same time, the shift member 32 connected to the piston member 30 is moved out of mesh with the large diameter idle gear G 12 . Power is transmitted from the input shaft 23 to the transmission shaft 24 at increased speed through the large diameter gear G 9 , small diameter idle gear G 11 , friction transmission portion 29 and clutch drum 27 . Then, the power is transmitted to the front axle case 9 through the front wheel driving shaft 26 . In this case, the front wheels 8 are driven at about twice the rear wheel peripheral velocity, thereby to provide a front wheel accelerating drive mode.
[0039] As shown in the hydraulic circuit diagram of FIG. 7 , the pressure oil supplying and draining passage for the shift clutch C 2 has, arranged in series, a front wheel control valve V 1 switchable as interlocked with steering of the front wheels 8 , an automatic change speed selector valve V 2 for turning on and off an automatic change speed of the front wheels 8 , and a check valve V 3 switchable as interlocked with shifting of the auxiliary change speed gear mechanism 19 . A hydraulic pump OP driven by the engine 1 delivers pressure oil through a power steering unit 87 and an oil cooler 88 to a hydraulic circuit “f” for front wheel change speed, Return oil from the hydraulic circuit “f” for front wheel change speed is supplied to a charge circuit “g” for the hydrostatic stepless transmission 12 .
[0040] As shown in FIGS. 6 and 7 , the front wheel control valve V 1 , automatic change speed selector valve V 2 and check valve V 3 are in the form of rotary valves, respectively, These valves V 1 , V 2 , and V 3 are assembled to a single valve casing 90 connected to the rear of clutch housing 2 . While the front wheel control valve V 1 and check valve V 3 are arranged in parallel, the automatic change speed selector valve V 2 located between the valves V 1 and V 3 has a spool axis extending perpendicular to the spool axes of the other valves V 1 and V 3 .
[0041] The front wheel control valve V 1 is mechanically interlocked to a steering mechanism 91 of the front wheels 8 . When the front wheels 8 are in a straight running state, the control valve V 1 shuts the oil passage. When the front wheels 8 are steered in excess of a predetermined angle (e.g. 35 degrees) left or right from the straight running state, the front wheel control valve V 1 is turned to open the oil passage. The automatic change speed selector valve V 2 is linked to a change lever 92 , to open the oil passage when the change lever 92 is in an automatic change speed “on” position, and shut the oil passage when the change lever 92 is in an automatic change speed “off” position. The check valve V 3 is linked to an auxiliary shift lever 93 for switching the auxiliary change speed gear mechanism 19 which provides three propelling speeds. The oil passage is opened when the auxiliary change speed gear mechanism 19 is shifted for the “low speed” or “intermediate speed”. The oil passage is shut when the auxiliary change speed gear mechanism 19 is shifted for the “high speed”.
[0042] Thus, only when the automatic change speed “on” position is selected for the automatic change speed selector valve V 2 to open the oil passage, and the auxiliary change speed gear mechanism 19 is shifted for the “low speed” or “intermediate speed” with the check valve V 3 opening the oil passage, the front wheel control valve V 1 is switched as interlocked to a steering operation exceeding the predetermined angle of the front wheels 8 , to supply the pressure oil to the shift clutch 25 . Then, the front wheels 8 are driven in acceleration for the tractor to make a smooth, small turn. When the auxiliary change speed gear mechanism 19 is shifted for “high speed” even though the automatic change speed “on” position is selected for the automatic change speed selector valve V 2 , the automatic front wheel acceleration is not carried out irrespective of a steering operation exceeding the predetermined angle of the front wheels 8 . When the automatic change speed “off” position is selected for the automatic change speed selector valve V 2 to close the oil passage, naturally the automatic front wheel acceleration never takes place in response to a front wheel steering operation.
[0043] A PTO transmission system will be described next.
[0044] The rear end of the input shaft 13 extending through and supported by the upper position of the main transmission 12 is aligned with a PTO transmission shaft 35 extending through and supported by the intermediate partition wall 3 a. A PTO clutch C 3 of the hydraulically operable multi-disk type is interposed between the input shaft 13 and PTO transmission shaft 35 .
[0045] As shown in FIG. 8 , the PTO clutch C 3 includes a clutch drum 37 splined to the rear end of the input shaft 13 , a shift member 38 shiftably splined to the PTO transmission shaft 35 , a clutch sleeve 39 shiftably splined to the shift member 38 , a friction transmission portion 40 of the multi-disk type interposed between the clutch drum 37 and clutch sleeve 39 , a clutch-operating piston member 41 contained in the clutch drum 37 , and an inner spring 42 for biasing the piston member 41 in a friction release direction. Pressure oil is supplied through an oil passage “c” formed in the PTO transmission shaft 35 to displace the piston member 41 against the force of spring 42 rightward in FIG. 8 . This places the friction transmission portion 40 in a pressure contact state, and thus a “clutch on” state. When the pressure oil supply is stopped, the piston member 41 is displaced by the sprint 42 leftward in FIG. 8 . This releases the friction transmission portion 40 from the pressure contact state, and thus a “clutch off” state.
[0046] A switching valve V 4 for PTO clutch operation is connected to the upper surface of the transmission case 3 for applying and stopping a control pressure to the oil passage “c” in the PTO transmission shaft 35 . The switching valve V 4 is operable by a PTO clutch lever CL disposed, to be pivotable fore and aft, at a left side of a driver's seat 61 .
[0047] As shown in FIGS. 13 and 14 , the PTO clutch lever CL has an operating path defining a “clutch on” position in a rearward region thereof, and a “clutch off” position in a forward region. When a “clutch on” state is selected, power transmitted to the clutch sleeve 39 is transmitted to the PTO transmission shaft 35 through the shift member 38 , and transmitted to a position rearward of the differential case 5 through an intermediate transmission shaft 43 connected coaxially to the rear end of the PTO transmission shaft 35 . The power is greatly decelerated by gears G 13 and G 14 arranged rearwardly of the differential case 5 , to be outputted from the rear PTO shaft 7 .
[0048] A PTO brake mechanism 45 is disposed rearwardly of the PTO clutch C 3 , which is interlocked to the “clutch off” operation to stop inertial rotation of the downstream transmission elements. The PTO brake mechanism 45 includes a friction plate 46 splined to the clutch sleeve 39 , a seat member 47 fixed to an inner wall of the transmission case 3 , and a braking plate 48 unrotatably supported inside the transmission case 3 . When the PTO clutch C 3 is disengaged to have the piston member 41 moved leftward in the drawings by the biasing force of inner spring 42 , the clutch sleeve 39 moves in the same direction with the piston member 41 . Then, the friction plate 46 is pinched between the seat member 47 and braking plate 48 to brake the clutch sleeve 39 .
[0049] As shown in FIG. 3 , the transmission case 3 has a mid-PTO case 51 connected to an undersurface thereof forwardly of the intermediate partition wall 3 a. The mid-PTO case 51 supports a mid-PTO shaft 50 projecting forward therefrom. The front portion forward of the intermediate partition wall 3 a of the transmission case 3 houses a mid-PTO transmission mechanism 52 for gear-interlocking the PTO transmission system and the mid-PTO shaft 50 , and a PTO mode selecting device 53 for switching between states of power takeoff from the rear PTO shaft 7 and from the mid-PTO shaft 50 .
[0050] The mid-PTO transmission mechanism 52 includes a power takeoff gear G 15 loosely fitted on a rear portion of the PTO transmission shaft 35 , and a gear G 16 formed integral with the mid-PTO shaft 50 , the gears G 15 and G 16 being interlocked through relay gears G 17 , G 18 and G 19 . The relay gear G 17 is loosely fitted on the front wheel driving transmission shaft 20 . The relay gear G 18 is loosely fitted on the propelling transmission shaft 17 . The relay gear G 19 is loosely fitted on a support shaft 54 mounted on a bottom wall of the transmission case 3 .
[0051] The PTO mode selecting device 53 is operable by shifting the shift member 38 forward and backward to select a mode for transmitting power only to the rear PTO shaft 7 , a mode for transmitting power to both the rear PTO shaft 7 and mid-PTO shaft 50 , or a mode for transmitting power only to the mid-PTO shaft 50 . When the shift member 38 is shifted to a foremost position, as shown in FIG. 9 , the shift member 38 is meshed only with splines 35 a of the PTO transmission shaft 35 . Then, the power transmitted to the shift member 38 through the PTO clutch C 3 is transmitted only to the rear PTO shaft 7 through the intermediate transmission shaft 43 .
[0052] When the shift member 38 is shifted to a fore and aft intermediate position, as shown in FIG. 8 , the shift member 38 is meshed with the splines 35 a of the PTO transmission shaft 35 and splined to a boss of the power takeoff gear G 15 . Then, the power transmitted to the shift member 38 through the PTO clutch C 3 is transmitted to the rear PTO shaft 7 through the intermediate transmission shaft 43 , and also to the mid-PTO shaft 50 through the mid-PTO transmission mechanism 52 .
[0053] When the shift member 38 is shifted to a rearmost position, as shown in FIG. 10 , the shift member 38 is splined only to the boss of the power takeoff gear G 15 . Then, the power transmitted to the shift member 38 through the PTO clutch C 3 is transmitted only to the mid-PTO shaft 50 through the mid-PTO transmission mechanism 52 .
[0054] A shaft coupling sleeve 55 extends between and is splined to the PTO transmission shaft 35 and intermediate transmission shaft 43 . When the PTO mode selecting device 53 selects the transmission mode for driving only the mid-PTO shaft 50 , the shaft coupling sleeve 55 acts as a PTO brake B for preventing inertial rotation of the rear PTO shaft 7 in free state.
[0055] The shaft coupling sleeve 55 is splined to be shiftable back and forth, and has a control system linked so that the shaft coupling sleeve 55 may be shifted in a reverse direction synchronously with the PTO mode selecting shift member 38 . Specifically, as shown in FIGS. 11 and 12 , a side wall of the transmission case 3 is penetrated by, and supports, a control shaft 56 having an eccentric operating pin 56 a for engaging the shift member 38 , and a control shaft 57 having a control arm 57 a for engaging the shaft coupling sleeve 55 . The control shaft 56 has an operating pin 56 b disposed at an outer end thereof and interlocked through a rod 59 to a PTO mode select lever 58 pivotable back and forth about an axis “p”. The control shaft 57 has a connecting lever 57 b extending from an outer end thereof and interlocked by a slot to the operating pin 56 b. The shift member 38 and shaft coupling sleeve 55 are shifted in opposite directions to each other by a fore and aft operation of the PTO mode select lever 58 .
[0056] Thus, when the PTO mode select lever 58 is operated to a rearmost position, the shift member 38 is shifted to the foremost position to select the transmission mode for driving only the rear PTO shaft 7 . When the PTO mode select lever 58 is operated to a fore and aft intermediate position, the shift member 38 is shifted to the fore and aft intermediate position to select the transmission mode for driving both the rear PTO shaft 7 and mid-PTO shaft 50 . In the above state, the shaft coupling sleeve 55 is in the rearmost position or fore and aft intermediate position in its shifting range. At this time, the shaft coupling sleeve 55 functions as a mere shaft coupling. When the PTO mode select lever 58 is operated to a foremost position, the shift member 38 is shifted to the rearmost position to select the transmission mode for driving only the mid-PTO shaft 50 . With the rearward shift of the shift member 38 , the shaft coupling sleeve 55 moves forward whereupon an engaging pawl 55 a at the forward end of the shaft coupling sleeve 55 engages a rib 60 formed on a rear surface of the intermediate partition wall 3 a in the transmission case 3 . As a result, the PTO brake B functions to stop rotation of the PTO transmission shaft 35 and intermediate transmission shaft 43 in a state of free rotation.
[0057] As shown in FIGS. 13 and 14 , the PTO mode select lever 58 is disposed at the left side of the driver's seat 61 to be pivotable back and forth. The PTO mode select lever 58 has an operating path formed directly rearwardly of the operating path of the PTO clutch lever CL. That is, the operating path of the PTO mode select lever 58 is substantially aligned with the operating path of the PTO clutch lever CL. Laterally outwardly of the PTO mode select lever 58 and PTO clutch lever CL, the auxiliary shift lever 93 noted hereinbefore is disposed to be pivotable back and forth.
[0058] As shown in FIG. 1 , lever lengths are selected so that the PTO clutch lever CL has a grip CLa thereof higher than a grip 58 a of the PTO mode select lever 58 . Thus, the driver's arm operating the PTO clutch lever CL can easily move clear of the PTO mode select lever 58 .
[0059] Arranged above and rearwardly of the differential case 5 are lift arms 95 for raising and lowering a working implement, and a lift cylinder 96 for driving the lift arms 95 . The lift cylinder 96 is controlled by a position control valve, not shown, linked to a position lever 97 disposed at the right side the driver's seat 61 . As shown in FIG. 15 , the position lever 97 is retainable in a selected control position by a frictional force of a plate spring 98 provided on a lever fulcrum. Thus, the lift arms 95 may be raised or lowered to and stopped at a height corresponding to a position in which the position lever 97 is retained. The plate spring 98 has a characteristic of spring load in relation to the amount of compression, which, as shown in FIG. 16 , includes a spring load stable region in an intermediate part of the deformation range. The plate spring 98 is assembled in this stable spring load condition, so that its frictional retaining function is not seriously affected by minor variations in the amount of compression due to a clamping error occurring in time of assembly.
[0060] FIGS. 18 , 19 (A) and 19 (B) show an operating guide for the PTO clutch lever CL that switches the PTO clutch control valve, and for the PTO mode select lever 58 .
[0061] The PTO clutch lever CL and PTO mode select lever 58 are arranged in fore and aft positions close to each other at the left side of the driver's seat 61 . These levers CL and 58 extend through a lever guide 63 attached to a fender 62 . The PTO clutch lever CL is mechanically interlocked to the valve V 4 through a link mechanism not shown, such that a forward operation of the PTO clutch lever CL provides a “clutch on” state, and a rearward operation thereof provides a “clutch off” state. Further, a restricting device 64 is provided between the PTO clutch lever CL and PTO mode select lever 58 for restricting operation of the PTO mode select lever 58 .
[0062] The restricting device 64 is disposed adjacent the undersurface of the lever guide 63 and, as shown in FIG. 20 , includes a bracket 65 mounted inside the lever guide 63 and fixedly screwed thereto from below, and an elongate restricting element 66 , which is an example of restricting member, pivotally supported by the bracket 65 to be swingable about a vertical fulcrum “m”. The fulcrum “m” is located in an intermediate position between a guide groove 67 of the PTO clutch lever CL and a guide groove 68 of the PTO mode select lever 58 . The restricting element 66 has a control portion 66 a extending forward from the fulcrum “m”, and a restricting portion 66 b extending rearward from the fulcrum “m”. Further, the restricting element 66 is biased to swing in one direction (i.e. counterclockwise in FIG. 19 ) by a torsion spring 69 mounted on the fulcrum “m”.
[0063] The control portion 66 a of the restricting element 66 overlaps a clutch-off region of the guide groove 67 of the PTO clutch lever CL, and has an inclined cam 70 formed on a side edge thereof for contacting and cooperating with the PTO clutch lever CL operated to the “clutch off” position. The restricting portion 66 b of the restricting element 66 is formed to have a length for overlapping a “mid-PTO drive” position and a “mid-/rear PTO drive” position in the guide groove 68 of the PTO mode select lever 58 . The restricting portion 66 b has, formed along a side edge thereof, a recess 71 for receiving and retaining the PTO mode select lever 58 in the “mid-PTO drive” position, and a recess 72 for receiving and retaining the PTO mode select lever 58 in the “mid-/rear PTO drive” position.
[0064] With the above restricting device 64 , when the PTO clutch lever CL is operated to the forward “clutch on” position, as shown in FIG. 19 (B), the restricting element 66 is in a free state and is swung by the biasing force into contact with a stopper 65 a bent from the bracket 65 , to be retained in a fore and aft posture. At this time, the restricting portion 66 b of the restricting element 66 overlaps the guide groove 68 of the PTO mode select lever 58 . The PTO mode select lever 58 in the “mid-PTO drive” position or “mid-/rear PTO drive” position is located in the recess 71 or recess 72 , to be inoperable to different positions. The PTO mode select lever 58 in the “rear PTO drive” position is prevented from operating forward by the rear end of the restricting element 66 .
[0065] When the PTO clutch lever CL is operated to the rearward “clutch off” position, as shown in FIG. 19 (A), the inclined cam 70 on the control portion 66 a of the restricting element 66 is contacted and pressed by the PTO clutch lever CL, whereby the restricting element 66 is forcibly swung clockwise against the force of torsion spring 69 . As a result, the restricting portion 66 b is retracted leftward from the guide groove 68 . The PTO mode select lever 58 can now be operated backward or forward as desired.
[0066] The restricting element 66 of the restricting device 64 is formed of a glossy metal plate material (e.g. plated sheet steel or stainless steel plate) to be clearly visible through the guide grooves 67 and 68 . Thus, the operator can easily make a visual or auditory recognition of a functional state of the restricting device 64 by a position of the restricting element 66 , or by a metallic sound produced in time of restricting operation. Consequently, when a selecting operation by the PTO mode select lever 58 becomes impossible, the operator is unlikely to operate the select lever 58 forcibly, thereby to damage the restricting device 64 or bend the PTO mode select lever 58 .
[0067] The bracket 65 has guide pieces 65 b and 65 c bent to project downward from positions forwardly and rearwardly of the fulcrum “m”. These guide pieces 65 b and 65 c have lower ends thereof shaped to make a sliding contact with the upper surface of the restricting element 66 , thereby to guide the latter to be retained stably in place.
Other Embodiments
[0068] (1) Where there is an allowance of space laterally of the driver's seat 61 , as shown in FIG. 17 , the operating paths of the PTO clutch lever CL and PTO mode select lever 58 may be arranged in fore and aft positions slightly staggered transversely from each other. The PTO clutch lever CL and PTO mode select lever 58 may be arranged at the right side of the driver's seat 61 .
[0069] (2) The PTO clutch C 3 is not limited to the hydraulically operable multidisk clutch, but may be a manually operable multidisk clutch or a claw clutch.
[0070] (3) The restricting device 64 may be provided between the link mechanism interlocking the PTO clutch lever CL and valve V 4 , and the switching link mechanism of the PTO mode select lever 58 .
[0071] (4) The restricting device 64 may be constructed electrically operable. For example, the control positions of the PTO clutch lever CL are electrically detected with a switch or the like. A lock member is provided to act on an appropriate part of the PTO mode select lever 58 or its control link mechanism. Upon detection of the PTO clutch lever CL in the “clutch on” position, the lock member is held in a lever locking position by means of a spring or the like. Upon detection of the PTO clutch lever CL in the “clutch off” position, a potential solenoid is operated to switch the lock member to a lock releasing position. | A tractor with a PTO apparatus, comprises: a plurality of wheels; a vehicle body supported by the plurality of wheels; an engine supported on the vehicle body; a rear PTO shaft disposed at a rear of the vehicle body for transmitting power from the engine; a mid-PTO shaft disposed under the vehicle body for transmitting power from the engine; a PTO mode selecting device having a first position for transmitting power only to the rear PTO shaft, a second position for transmitting power to both the rear PTO shaft and said mid-PTO shaft, and a third position for transmitting power only to said mid-PTO shaft; a PTO clutch disposed on a transmission line upstream of said PTO mode selecting device and switchable between an engaged position and a disengaged position; and a restricting mechanism for preventing a change operation of said PTO mode selecting device when said PTO clutch is in the engaged position, and permitting the change operation of said PTO mode selecting device when said PTO clutch is in the disengaged position. | 8 |
BACKGROUND OF THE INVENTION
[0001] The invention relates to a process to disperge a recycled fibre pulp, where a pre-dewatered pulp is heated, conveyed, and disperged in a disperger. It also refers to a device for implementing the process.
[0002] A process and a device of this type are known, e.g. from NO 302 186 B1. Here, the recycled fibre pulp from a dewatering screw is fed to a heating screw, from where the heated pulp is brought into the plug feeder for a disperger. The pulp is then disperged in the disperger. The particular disadvantage here is the amount of equipment needed and the space required for this type of plant. Further processes and devices of this type are known, for example, from DE 199 54 246 A1. On the one hand, the plant described is similar to NO 302 186 B1, and on the other, it also includes the option of feeding in steam directly between the refiner plates of the disperger. The disadvantage of the latter method is that the possible retention time is very short and thus, cannot provide full and even heating.
SUMMARY OF THE INVENTION
[0003] The aim of the invention is thus to provide a process with which to guarantee good and even heating using a small amount of equipment and also where additional chemicals can be added before disperging if necessary.
[0004] The invention is thus characterised by the recycled fibre pulp being heated immediately before entering the disperging zone. As a result, an additional unit, such as a heating screw, can be omitted, while still guaranteeing thorough warming of all particles. Thus, the disperging zone can be fed well-heated recycled fibre pulp.
[0005] If, according to an advantageous feature of the invention, the recycled fibre pulp is mixed thoroughly while it is being heated, this will provide even warming.
[0006] If the recycled fibre pulp is heated by steam and if a vacuum is applied at the conveying unit at the same time, the steam can be well targeted and heat transfer to the recycled fibre pulp optimised.
[0007] It is also an advantage to remove the cooled excess steam after it has flowed through the recycled fibre pulp.
[0008] In many applications it can also be an advantage to mix chemicals into the recycled fibre pulp. By heating and adding chemicals at the same time, a uniform reaction can be obtained.
[0009] In addition, the invention relates to a device for disperging a recycled fibre pulp, comprising a feed unit for steam, a conveying unit, and a disperger. It is characterised by the conveying unit having at least one connection piece or inlet openings for steam. This can be used to heat the recycled fibre pulp shortly before it reaches the disperger, thus dispensing with the need for an additional heating unit.
[0010] If the conveying unit is designed as a mixing screw, according to the invention, this will provide even mixing with the steam and thus, even heating.
[0011] If, according to a further feature of the invention, at least one connection piece is designed as a vacuum connection, this will achieve targeted steam flow control and optimum heat transfer.
[0012] If the connection pieces are mounted at the housing of the conveying unit, a mixing screw for example, this will provide a good heating effect.
[0013] A particularly advantageous further development of the invention is characterised by the conveying unit, for example a mixing screw, having a hollow shaft, where the hollow shaft can have spikes for mixing purposes. With this arrangement the steam supply is integral with the shaft and can be directed along the conveying path, which will lead to more even distribution and thus, more even heating.
[0014] If the inlet openings of the spikes are mounted at different radii on the conveying unit, for example a mixing screw, steam and/or chemicals can be fed in evenly, also over the cross-section of the conveying screw.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] The invention will now be described using the examples shown in the drawings, where:
[0016] FIG. 1 shows a state-of-the-art plant;
[0017] FIG. 2 shows a horizontal projection of a plant according to the invention;
[0018] FIG. 3 is a view of FIG. 2 according to the arrow marked III;
[0019] FIG. 4 shows a sectional view of a device according to the invention;
[0020] FIG. 5 is a schematic view of a variant of the invention;
[0021] FIG. 6 shows a special configuration of the invention; and
[0022] FIG. 7 is a sectional view of FIG. 4 with another variant of the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0023] FIG. 1 shows a state-of-the-art plant, where a screw press 1 is provided to dewater the recycled fibre suspension. The dewatered suspension is then fed at a consistency of approximately 20-35%, preferably 25-30%, through a chute 2 to a heating device 3 with rotating blades. Subsequently, the heated suspension drops into an endless screw 4 for feeding to the disperger 5 . The steam is fed to the heating device 3 through a steam pipe 6 , with some of this steam also being fed in beforehand in the chute 2 . The suspension to be treated is supplied to the screw press 1 through an inlet branch 7 and leaves it at the end in plug form 8 . The plug 8 at the end of the screw press 1 acts here as a vapour trap or barrier.
[0024] FIG. 2 shows a horizontal projection of a plant according to the invention. Here, the recycled fibre suspension to be treated is also dewatered in a screw press 1 and fed through a chute 2 to a plug screw 8 ′ and/or then to a conveying unit 9 , which can be designed as a feed screw, to a disperger 5 . In addition, pipework 10 , 10 ′ is shown here through which steam and chemicals, respectively, are fed to the recycled fibre pulp. The chemicals that may be added are either liquid or gaseous bleaching and hygiene chemicals, such as peroxide, caustic soda, chlorine, ozone, or disperging agent.
[0025] FIG. 3 is a view of FIG. 2 according to the arrow marked III. The screw press 1 is linked to the plug screw 8 ′ via a chute 2 . The recycled fibre suspension is then brought to the conveying unit 9 , particularly a feed screw, where the plug screw 8 ′ also acts as a vapour trap for the steam fed in through the pipe 10 . The disperger 5 is then located behind the feed screw.
[0026] FIG. 4 contains a sectional view through a device according to the invention. The illustration shows where the plug screw 8 ′ joins the feed section 9 of the endless screw. To supply the steam, connection pieces 11 can be provided at the casing 12 at the beginning of the endless screw or connection pieces 11 ′ or 11 ″ at the end section of the endless screw. As an alternative, chemicals can be fed in through these connection pieces. If the conveying unit, particularly a feed screw, is designed with a hollow shaft 13 , steam and/or chemicals can also be fed in direction 14 through the hollow shaft. It is a particular advantage if spikes 16 are provided between the screw flights 15 . With this arrangement, the steam can also be fed in easily, distributed evenly over the cross-section of the endless screw.
[0027] If the steam is fed in through the connection pieces 11 , 11 ′ or 11 ″, a vacuum (in the opposite direction to 14 ) can be applied to the hollow shaft 13 . As an alternative, steam can be fed in through the hollow shaft 13 and preferably extracted by suction through connection pieces 11 . In this case, chemicals can be added through the connection pieces 11 ′ and/or 11 ″. The suspension is then fed to the disperger after being heated thoroughly and mixed well.
[0028] FIG. 5 shows a schematic view of a device according to the invention, where steam is added in direction 14 through the hollow shaft 13 . The steam is discharged evenly at different points over the length of the shaft. The recycled fibre suspension has a temperature of approximately 20° C. up to 80° C. here, usually 40-60° C. The excess steam is then extracted by suction through the connection pieces 11 , 11 ′ and 11 ″. The connection pieces 11 , 11 ′ and 11 ″ can be designed as channels on the screw casing 12 , fully or partly around the circumference. Immediately before entering the disperging zone, e.g., between the relatively rotating plates (where the contaminants are removed from the recycled fibre suspension and/or intimate chemical mixing is completed), the temperature of the suspension rises beyond 85° C. This immediacy is optimized because the heating is performed in the feed device 9 for the disperger plates 5 , which is coaxially rotated adjacent to the plates.
[0029] FIG. 6 illustrates a means of supplying the steam. The screw flight 15 mounted on the hollow shaft 13 is supported by a wall 18 in such a way as to form a cavity 19 . The steam flows out of the hollow shaft 13 through holes 20 into the cavity 19 and is then fed to the recycled fibre suspension through inlet openings 21 , 21 ′. Depending on the position of the inlet openings 21 , 21 ′, the steam can be fed to the suspension at different points in the cross-section of the conveying unit 9 , particularly a feed screw.
[0030] FIG. 7 corresponds to a section through the line marked VII-VII in FIG. 4 . The hollow shaft 13 running inside the screw casing 12 has several heating spikes 16 which can be of different lengths. For steam feed to the suspension the spikes 16 have inlet openings 21 , 21 ′, which guarantee distribution over the cross-section of the conveying unit 9 . The spikes 16 can also be open at the top end (pointing away from the shaft). | The invention relates to a process for disperging a recycled fibre pulp, where a pre-dewatered pulp is heated, conveyed, and disperged in a disperger. It is mainly characterised the recycled fibre pulp being heated immediately before entering the disperging zone. In addition, the invention refers to a device for implementing the process. | 3 |
This is a continuation of application Ser. No. 08/326,079 filed on Oct. 19, 1994 and now abandoned.
BACKGROUND OF THE INVENTION
This invention pertains to the art of molding machines and more particularly to a molding machine generally referred to as a vertical flaskless molding machine in which sand received through a vertical hopper is compressed into a desired configuration defining an open top casting cavity. A series of these sand molds are then strung together and advanced along a conveyor for subsequent receipt of molten metal into the cavity at a downstream pouring station.
The invention is particularly applicable to an aerator assembly for use in a vertical molding machine of this type and will be described with particular reference thereto. However, it will be appreciated that the application has broader applications and may be advantageously employed in other related environments and applications.
Known vertical flaskless molding machines, as an example, provide a supply of sand on an inlet conveyor to a hopper where regulated amounts of the sand in the hopper are subsequently introduced into a molding chamber. Clay and other materials that comprise the sand may tend to bind and clump the sand together, a situation that is undesirable where uniform distribution or density of the sand in the mold is desired. In an effort to address binding and clumping of the sand, mold manufacturers supply an aerator assembly that mechanically aerates the supply sand. One commercially available aerator assembly uses a series of paddles, blades, or similar structures situated over the inlet conveyor. The paddles contact the sand as it is transported along the conveyor. The aerator paddles rotate in a fixed direction and at a fixed speed in an attempt to break up the sand before it enters the hopper.
Although widely used, and addressing a portion of the sand binding problems, situating the aerator assembly above the inlet conveyor still does not adequately address introduction of the sand into the mold chamber and the desired goal of uniform density. Various portions of the mold chamber have a greater density of sand than other portions of the chamber. Even though the sand is subsequently pressed to a desired shape, the variation in density can adversely effect the quality of the molded product.
Therefore, even though some aspects of the non-uniform density were addressed by these prior art arrangements, there is no ability to change the displacement and fill rate of the sand into the mold chamber. The fixed direction and speed of the paddles provide minimal aeration.
As with any mechanical device, it is also preferable that any modified aerator assembly be easily serviced and operated. Accordingly, these are still other deficiencies found in the prior art and which have been adequately addressed by the subject invention.
SUMMARY OF THE INVENTION
The present invention contemplates a new and improved aerator assembly that overcomes all of the above-referenced problems and others and provides a more uniform density of sand in a vertical flaskless molding machine. While obtaining all of these goals, the new aerator assembly is still simple and economical to manufacture, operate, and service.
According to the present invention, a chute is adapted to receive the fill (sand) at one end and discharge the fill at a second end to the molding chamber. Plural tines are disposed in the chute between the inlet and outlet and contact the fill as it proceeds vertically through the chute.
According to another aspect of the invention, the tines are mounted on separate shafts that are independently driven by separate motors in response to signals provided by independent controllers.
According to yet another aspect of the invention, the tines on respective shafts are offset relative to one another.
A principal advantage of the invention is the ability to adequately aerate the fill material as it proceeds from the upper, first end of the chute to the lower, second end thereof.
Yet another advantage results from the uniform density and greater control over the fill rate of sand introduced to the mold chamber.
A still further advantage is realized by the simplified structure that can be easily manufactured, operated, and serviced.
Still other advantages and benefits of the invention will become apparent to those skilled in the art upon a reading and understanding of the following detailed description.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention may take physical form in certain parts and arrangements of parts, a preferred embodiment of which will be described in detail in this specification and illustrated in the accompanying drawings which form a part hereof, and wherein:
FIG. 1 is a side elevational schematic view of the subject new aerator assembly on a vertical flaskless molding machine;
FIG. 2 is an overhead plan view of the aerator assembly; and,
FIG. 3 is an enlarged elevational view partly in cross-section of the aerator assembly.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to the drawings wherein the showings are for purposes of illustrating the preferred embodiment of the invention only and not for limiting same, the figures show a vertical flaskless molding machine or apparatus A that includes an aerator assembly B. More particularly, and with reference to FIG. 1, the molding machine is used to cast metal products in sand molds. A supply of molding sand 10 is typically provided on an inlet conveyor such as a continuous loop belt 12. The belt rotates in a generally clockwise direction, as shown, about rollers 14, 16. The rollers rotate about parallel, horizontal axes to feed the sand into a chute 20.
The chute 20 defines a housing of the aerator assembly B and includes a first or upper end 22 having an enlarged cross-sectional area and a second or lower end 24 having a reduced cross-sectional area. Thus, the chute has a tapered, partially conical configuration that receives the sand and funnels it toward a molding chamber C. A valve 26 is disposed in the lower end of the chute to control the input of sand fill to the molding chamber. The valve can be of any known acceptable type, such as a slide or gate valve, dome valve, butterfly valve, or the like. Moreover, a blow chamber D is located below the valve 26 and above the molding chamber. Its structure and operation form no part of the subject invention so that further discussion herein is deemed unnecessary.
Mounted in the chute is a mixing member defined in the preferred embodiment by a plurality of shafts or spindles 28a, 28b, 28c (FIG. 2). The shafts extend in a common, generally horizontal plane across an intermediate region of the chute and are each supported at opposite ends by bearing assemblies 40, 42. Each of the shafts includes a series of diametrically oriented through openings 44. The openings are spaced apart along the longitudinal axis of each shaft and are alternately oriented in generally orthogonal relation. The openings 44 are each adapted to receive a tine 46 that is preferably defined by a stainless steel roll pin. The roll pin configuration permits the tine to be inserted in one end of the opening 44 so that its cross section is reduced as it is advanced through the opening. The tine then tends to expand as it exits on the opposite side of the shaft. In this manner, the tines extend generally radially outward from their respective shafts.
As best illustrated in FIG. 2, most of the tines have the same length, although tines disposed adjacent ends of the shafts may have a reduced length to prevent contact with the sidewall of the chute 20. Moreover, the tines are oriented in alternating, orthogonal relationship along each shaft as described above and are offset from tines disposed on adjacent shafts. That is, tines disposed at relatively the same axial location on adjacent shafts are oriented 90 degrees out of phase. In any event, and due to the differing rotational speed as will be described further below, the tines are dimensioned so that they will not interfere with the tines of an adjacent shaft even when the tines are oriented in the same direction. The tines do, however, extend over substantially the entire cross-sectional area of the chute.
Each shaft is individually operated by a drive motor 50. In the illustrated preferred embodiment employing three shafts, the drive motors 50a, 50b, 50c are direct drive units with an associated AC inverter. A programmable logic controller (PLC) 70 is operatively connected to the drive units of the motors and the PLC controls not only the rotational speed, but also the rotational direction of the individual shafts. Thus, shaft 50b may be rotating in a direction opposite that of shafts 50a and 50c. Likewise, any one, or all three, of the shafts may be operated at different speeds or directions as desired for a particular application. For a particular molding operation, information may be preprogrammed in the PLC or necessary adjustments can be made via a rheostat or similar variable control arrangement if so desired.
To facilitate passage of the sand through the chute 20, interior wall 52 (FIG. 3) of the chute is preferably formed of a lubricious material. For example, a material having an ultra-high molecular weight (UHMW) is preferred to provide a smooth surface that contributes to the overall flow of sand fill through the chute.
By controlling the operative speed and rotation of the individual shafts, the displacement and fill rate of sand to the molding chamber C can likewise be controlled. The aerator assembly contributes to discharge of sand fill at a uniform density into the chamber. It is also preferably located between the feed conveyor and the molding chamber, i.e., in the vertical path therebetween, to provide even greater accuracy and control of the fill.
Once the chamber C is filled in known vertical flaskless molding machines, valve 26 is closed and plates 60, 62 (FIG. 1) are relatively advanced toward one another to compress the sand into the desired mold configuration. After the compression stroke is complete, the sand mold is then ejected from the chamber and advanced to the end of a string of similar molds. At a downstream location molten metal is then poured into an open, upper end of adjacent molds to fill the cavities and form the desired workpiece. Details of the molding, cooling, and advancement of the mold string are well known in the art and form no part of the subject invention so that further details herein are deemed unnecessary.
It is contemplated that various alterations can be made to the preferred embodiment. For example, different orientations of the shafts and tines may be preferred for selected applications. Moreover, different control arrangements for the individual shafts may be advantageous, although it is believed that independent, individual control of each shaft is preferred. Different numbers of shafts or lengths of tines may be desired for still other applications. None of these changes, however, is deemed to significantly depart from the overall scope and content of the subject invention.
The invention has been described with reference to the preferred embodiment. Obviously, modifications and alterations will occur to others upon a reading and understanding of this specification. It is intended to include all such modifications and alterations insofar as they come within the scope of the appended claims or the equivalents thereof. | The assembly includes plural independently operated rotating shafts that contact the sand fill. As the fill is introduced into a first end of the vertical chute, the speed and rotational direction of the shafts with accompanying tines are controlled to regulate the feed rate and discharge of the fill to a molding chamber. This arrangement provides a more uniform density in the molding chamber which, in turn, results in improved quality in the cast product. | 1 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This is a continuation-in-part of U.S. patent application Ser. No. 12/476,111, filed 1 Jun. 2009, which is a continuation-in-part of U.S. patent application Ser. No. 12/408,384, filed 20 Mar. 2009, which is a continuation-in-part of U.S. patent application Ser. No. 12/272,340, filed 17 Nov. 2008, which is a continuation-in-part of my U.S. patent application Ser. No. 11/331,440, filed 11 Jan. 2006, all of which are incorporated herein by reference.
Priority of my U.S. Provisional Patent Application Ser. No. 61/370,746, filed 4 Aug. 2010, incorporated herein by reference, is hereby claimed.
My U.S. Provisional Patent Application Ser. No. 60/642,789, filed 11 Jan. 2005, is incorporated herein by reference.
My U.S. Provisional Patent Application Ser. No. 60/988,159, filed 15 Nov. 2007, is incorporated herein by reference.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
Not applicable
REFERENCE TO A “MICROFICHE APPENDIX”
Not applicable
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to fishing with bait, such as live bait (minnows, shrimp, small fish), or dead bait or manufactured or synthetic. More particularly, the present invention relates to a method and apparatus that alerts a fisherman that his or her hook is bare, no longer baited.
2. General Background of the Invention
Fisherman often attempt to lure fish to a hook using a bait article that can be either live bait or dead bait. Bait is understood to mean anything that can be placed on a hook to attract a fish. Examples of live bait include minnows, shrimp, small fish, worms, insects or the like. Examples of dead bait include frozen or cooled items such as shrimp, fish, and insects as examples. The website of Bass Pro Shops (www.basspro.com) gives examples of many baits. Some bait articles can be attached to the hook which are neither live nor fresh/frozen but are plastic or other synthetic material, sometimes referred to as trailers. Bass Pro Shops also sells preserved baits that could be attached to a hook such as, for example eggs, worms, dough, and the like.
One of the problems facing a fisherman is the loss of a bait article while fishing. These bait articles can become dislodged from the hook that supports them because of a number of different reasons. In some situations, a smaller fish simply removes the bait from the hook without becoming impaled. Sometimes a fish will strike, remove the bait, and not be impaled by the hook. In some situations, tide flow slowly pulls at the bait until it becomes disconnected from the hook. In some situations, the bait can be removed from the hook because of underwater structure such as grass, sticks, limbs, gravel and the like. Sometimes bait will fall off the hook when the angler makes his cast.
If the fisherman has some doubt whether or not the bait is still connected to the hook, he or she typically has only one option, namely reeling in the hook and checking it out.
If the bait is still on the hook, it was needlessly removed from the fishing area, reducing the chances of catching a fish. If the hook was bare, a fisherman must wonder how long it was bare and are the fish still in the vicinity or did they move on because there was no more bait to entice them. There remains a need for a device to let an angler know immediately when there is no longer any bait on the hook. Modern fishing can be boiled down to a time management endeavor. Since one cannot fish 24 hours a day, seven days a week, an angler must, in the limited time available for him, 1) find a location where the fish are, 2) be at that location when they are ready to feed, 3) present to the fish a bait they feel like eating and 4) keep a bait in the feeding area as much as possible during their active feeding times. There is only a certain amount of time during the day when at a given location, there will be actively feeding fish. If an angler is lucky enough to be at the right spot, at the right time, with the right bait on the hook, the odds of a successful fishing trip are in his favor, and are increased the greater the time a baited hook is in the water.
Reeling the line in to check for a baited hook decreases efficiency. Repeatedly casting the bait can stun or kill it, making it less attractive to the fish.
None of the previous art answers one of the most basic questions of bait fishing: Is there still bait on the hook? The key to solving the problem and increasing an angler's efficiency and enjoyment, is to be able to know when a hook no longer has bait on it without having to remove it from the strike area.
The following patent documents are incorporated herein by reference:
U.S. Pat. Nos. 4,461,114 5,351,432 5,615,512 5,937,566 5,974,721 6,079,144 6,796,077; U.K. Patent No. GB 2245467. U.S. Pat. No. 5,974,721 discloses a light emitting fishing float that is activated when a fish contacts the hook. U.S. Pat. No. 6,079,144 discloses a motion-actuated light with a fish hook and float that flashes when contact is made with spaced conductive areas that form a circuit. U.S. Pat. No. 6,796,077 discloses a lighted lure with a conductive weed guard that turns off when a fish is hooked. U.S. Pat. No. 4,625,446 is directed to fish bite by pressure sensor. U.S. Pat. No. 5,581,930 is a remote activity sensing system. U.S. Pat. No. 6,671,994 discloses a fish strike indicator. U.S. Pat. No. 6,138,398 discloses a fish strike indicator. U.S. Pat. No. 5,898,372 discloses a lighted fishing float with a motion detector.
BRIEF SUMMARY OF THE INVENTION
The present invention employs floats and a hook with a float assembly connected to the bait. When bait is no longer on the hook, the float is released, and either alerts the fisherman that his or her bait is gone by floating to the surface, or interacts with a surface signal float to alert the angler.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
For a further understanding of the nature, objects, and advantages of the present invention, reference should be had to the following detailed description, read in conjunction with the following drawings, wherein like reference numerals denote like elements and wherein:
FIG. 1 is a perspective view of an embodiment of the apparatus of the present invention;
FIG. 2 is a sectional elevation view of an embodiment of the apparatus of the present invention;
FIG. 3 is a partial exploded perspective view of an embodiment of the apparatus of the present invention;
FIG. 4 is a sectional elevation view of an embodiment of the apparatus of the present invention;
FIG. 5 is a sectional elevation view of an embodiment of the apparatus of the present invention;
FIG. 6 is an elevation view of an embodiment of the apparatus of the present invention;
Signal Float-Sliding Rig Deployed Configuration
FIG. 7 is an elevation view of an embodiment of the apparatus of the present invention;
FIG. 8 is a partial sectional elevation view of an embodiment of the apparatus of the present invention;
FIG. 9 is a partial sectional elevation view of an embodiment of the apparatus of the present invention;
FIG. 10 is a sectional elevation view of an embodiment of the apparatus of the present invention;
FIG. 11 is a partial perspective view of an embodiment of the apparatus of the present invention;
FIG. 12 is a partial perspective view of an embodiment of the apparatus of the present invention;
FIG. 13 is an exploded perspective view of an embodiment of the apparatus of the present invention;
FIG. 14 is a sectional elevation view of an embodiment of the apparatus of the present invention;
FIG. 15 is a sectional elevation view of an embodiment of the apparatus of the present invention;
FIG. 16 is a sectional elevation view of an embodiment of the apparatus of the present invention;
FIG. 17 is a partially exploded partial perspective view of an embodiment of the apparatus of the present invention;
FIG. 18 is a partial sectional elevation view of an embodiment of the apparatus of the present invention;
FIG. 19 is a partial elevation view of an embodiment of the apparatus of the present invention;
FIG. 20 is a partial elevation view of an embodiment of the apparatus of the present invention;
FIG. 21 is a partial elevation view of an embodiment of the apparatus of the present invention;
FIG. 22-24 are circuit diagrams showing parts of an embodiment of the apparatus of the present invention.
FIG. 25 is partial perspective view of an embodiment of the apparatus of the present invention;
FIG. 26 is a partial sectional elevation view of an embodiment of the apparatus of the present invention;
FIG. 27 is a partial perspective view of an embodiment of the apparatus of the present invention;
FIG. 28 is a partial sectional elevation view of an embodiment of the apparatus of the present invention;
FIG. 29 is a partial perspective view of an embodiment of the apparatus of the present invention;
FIG. 30 is a partial sectional elevation view of an embodiment of the apparatus of the present invention;
FIG. 31 is a partial perspective view of an embodiment of the apparatus of the present invention;
FIG. 32 is a partial sectional view of an embodiment of the apparatus of the present invention;
FIG. 33 is a partial perspective view of an embodiment of the apparatus of the present invention;
FIG. 34 is a partial sectional elevation view of an embodiment of the apparatus of the present invention;
FIG. 35 is a partial top view of an embodiment of the apparatus of the present invention;
FIG. 36 is a sectional elevation view of an embodiment of the apparatus of the present invention;
FIG. 37 is a sectional elevation view of an embodiment of the apparatus of the present invention;
FIG. 38 is a sectional elevation view of an embodiment of the apparatus of the present invention;
FIG. 39 is a sectional elevation view of an embodiment of the apparatus of the present invention;
FIG. 40 is a partial sectional elevation view of an embodiment of the apparatus of the present invention;
FIG. 41 is a sectional elevation view of an embodiment of the apparatus of the present invention;
FIG. 42 is a partial sectional view of an embodiment of the apparatus of the present invention;
FIG. 43 is a partial cut-away top view of an embodiment of the apparatus of the present invention;
FIG. 44 is a sectional elevation view of an embodiment of the apparatus of the present invention; and
FIG. 45 is a sectional elevation view of an embodiment of the apparatus of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
The figures show preferred embodiments of the fishing apparatus of the present invention. The fishing apparatus of the present invention is preferably used by an angler using a bait article 1 while fishing. In FIG. 1 the bait article 1 can be for example a live bait article, such as a minnow as is shown. However the bait article 1 can be any known article of live, fresh, frozen, or preserved bait and/or any bait article that is synthetic or artificial, such as those shown at the website www.basspro.com.
In FIG. 1 the bait article 1 is attached to a hook 2 . Small pieces of tubing or other similarly affixable material, known as slide stoppers 42 , FIG. 20 , may be affixed to the hook 2 above and below the bait article 1 to keep the bait article 1 properly positioned on the hook 2 . The hook 2 shown is a general representation and may be replaced with any known fishing hook, such as a treble hook, circle hook, jig head hook, or weighted fishing hook. Fishing line 3 is affixed to the hook eye 52 on its distal end, FIG. 1 . If the fishing line 3 is segmented, the segments may be of the same or differing types and dimensions and will preferably be connected in line, end to end, by any known means such as a knots, clips, rings, or swivels (line connector 4 ) to form one continuous fishing line 3 , FIG. 1 . An optional sinker 5 may be used. An impaling and holding device, known as the bait anchor 6 , securely holds the bait article 1 to a line, known as the tether line 7 , FIG. 1 . The bait anchor 6 preferably has a pointed distal end and a means to deter separation of the coupled objects such as the use of a barb or barbettes located along the sides of the device, and an eye on its proximal end for attachment of a line. One end of the tether line 7 is preferably secured to the bait anchor 6 , while the other end of the tether line 7 is preferably secured to a float known as the trigger float 8 , FIG. 1 . The trigger float 8 preferably can only move along the length of the fishing line 3 . The trigger float 8 preferably has an annular magnet known as the trigger magnet 9 affixed to its upper surface, FIG. 1 . The fishing line 3 preferably passes unfettered through a centrally located through-hole known as the trigger magnet line hole 49 , of annular trigger magnet 9 and the trigger float line hole 48 , FIG. 1 . The trigger float 8 and trigger magnet 9 may be joined together by a connecting tube 10 FIG. 4 which runs through their central line holes, fitting tightly to their inner diameter walls, or by a suitable adhesive or other fastener such as a fenestrated retention band encircling both the trigger float 8 and trigger magnet 9 . The connecting tube 10 , FIG. 4 can also secure the tether line 7 to the trigger float 8 by pinning the tether line 7 to the walls of the trigger float line hole 48 . The tether line 7 may exit the trigger float 8 from the bottom, or if there is a worry about tangling the tether line 7 with the fishing line 3 , the tether line 7 could exit from the top of the trigger float 8 which would cause greater separation between the two lines, FIGS. 18 , 19 , and 20 . The bait assembly 90 is preferably made up of fishing line 3 , trigger magnet 9 , trigger float 8 , line connector 4 , sinker 5 , tether line 7 , bait anchor 6 , hook eye 52 , and hook 2 , but may be modified as known to one skilled in the art.
In this example of trigger float 8 , FIG. 4 the fishing line 3 passes unfettered though the connecting tube 10 , which is holding the trigger magnet 9 and trigger float together. The trigger float 8 is preferably located above any fishing line tackle such as the line connector 4 (swivel), or sinker 5 , or they preferably are small enough to not impede the movement of trigger float 8 along the fishing line 3 .
An optional hook line guide 41 , FIG. 21 , in this example a loop affixed to the hook 2 which is used to redirect the buoyancy pull of the trigger float 8 when it is greater than the drag of the bait article 1 and the hook 2 . In this situation, the lower end of the hook 2 and bait article 1 would want to rise up, resulting in an undesirable orientation if the hook line guide 41 were not present to prevent its occurrence. The inner diameter of the hook line guide 46 preferably is large enough to allow easy passage of the bait anchor 6 .
The fishing line 3 preferably connects the hook 2 to a fishing pole/fishing rod-reel 43 , FIG. 5 , or any other object the angler deems suitable such as a tree limb, piling, rock, appendage, etc.
Some distance above the trigger float 8 along the fishing line 3 there can be another float known as the signal float 11 , FIGS. 1 and 2 . The body of the signal float 11 preferably consists of three sections which are joined together in a waterproof and air-tight manner. The three sections are the top cap 12 , the tube body 13 , and the bottom cap 14 . The top cap 12 closes one end of the tube body 13 , while the bottom cap 14 closes the other end of tube body 13 . The joining of the three sections may be aided by using fastening aids such as adhesives, screws, or elastic bands. It is preferable to have the ability to disconnect at least the bottom section when needed, to service the interior parts of the signal float 11 .
The external inferior surface of the bottom cap 14 , FIG. 2 , preferably has a central through-hole known as the water vent 17 which opens into the interior space of signal float 11 . A distance outward from the water vent 17 , vertical slotted walls, known as the magnet chamber walls 73 , encircle the water vent 17 , FIG. 3 . The slots in magnet chamber walls 73 are known as chamber vents 74 , FIG. 3 . The space encompassed by the magnet chamber walls 73 is known as the magnet chamber 23 , FIG. 8 . The bottom of the magnet chamber 23 is enclosed by a cap known as the end cap 24 , FIG. 3 , whose vertical slotted walls fit tightly against the magnet chamber walls 73 with their respective slots oriented facing each other, FIG. 8 . The slots in the walls of the end cap 24 are known as the cap vents 26 , FIG. 3 . The chamber vents 74 and the cap vents 26 are preferably oriented parallel with each other, forming one continuous vent from outside to inside the magnet chamber 23 , FIG. 8 . The end cap 24 bottom surface preferably has a through-hole, known as the end cap line hole 25 , FIG. 8 , preferably centrally located, which communicates with the space of the magnet chamber 23 . The fishing line 3 passes freely through the end cap line hole 25 , FIG. 8 .
The interior surface of the bottom cap 14 , FIG. 3 , preferably has projections extending from the sides and bottom surfaces toward the water vent 17 , which form sockets known as ballast sockets 27 . These ballast sockets 27 can securely hold sinkers known as ballast sinkers 28 or noisemakers 29 . The walls of the ballast sockets 27 preferably do not extend all the way to the water vent 17 .
The upper surface of the top cap 12 , FIG. 1 , preferably has a raised area known as the plateau 47 , in its center which extends outward a distance. The center of the upper surface of the top cap 12 preferably has a vertical through-hole known as the top cap line hole 31 , from the upper surface of the plateau 47 to the interior of the signal float 11 , FIG. 2 . The fishing line 3 preferably passes freely through the top cap line hole 31 . There is preferably at least one vertical socket known as the light socket 33 , extending from the upper surface of the plateau 47 downward, but is preferably not deep enough to penetrate the inferior surface of the top cap 12 . The light socket 33 preferably provides an anchor point for a chemical light stick 44 , FIG. 1 , for use in low light conditions, or any other item an angler may decide to attach to the signal float 11 . There is preferably a through-hole, known as the anchor hole 30 , FIG. 1 , which preferably extends from one of the sides of the plateau 47 through to the opposite side of the plateau 47 . The anchor hole 30 preferably intersects and passes through the top cap line hole 31 and its diameter is preferably equal to or greater than the diameter of the top cap line hole 31 . There is preferably at least one other hole, known as the auxiliary air vent 32 , FIG. 1 , extending from a side of the plateau, preferably below the level of the anchor hole 30 , which penetrates one side of the top cap line hole 31 FIG. 1 . The location of the auxiliary air vent 32 is not limited to the area described, as long as it allows communication between the exterior atmosphere and the interior of signal float 11 when needed and is capable of being closed when needed. The auxiliary air vent 32 could also be a through hole located on the peg 34 perpendicular to, and intersecting, the peg line hole 35 . If located on the peg 34 , the auxiliary vent hole would preferably be in line with the top cap line hole 31 when peg 34 is inserted properly into the anchor hole 30 .
The interior horizontal surface of the top cap 12 , FIG. 2 , preferably has the top cap line hole 31 running through its center. A clear space extends around the top cap line hole 31 for a distance until it abuts the encircling vertical slotted walls known as the piston seal guide 46 .
Inside the magnet chamber 23 is an annular magnet, known as the water vent magnet 19 , FIG. 2 . The water vent magnet 19 preferably can move freely up and down the inner space of the magnet chamber 23 . The water vent magnet 19 is preferably situated horizontally so that its interior space is in line with all the line holes of the various parts of the signal float 11 .
There is a tube, known as the piston tube 15 , FIG. 2 , inside the signal float 11 . The exterior wall of the bottom end of the piston tube 15 preferably fits tightly against the inner diameter wall of the annular water vent magnet 19 , inside the magnet chamber 23 . The piston tube 15 preferably extends through the water vent 17 , through the interior of the signal float 11 . The upper end of the piston tube 15 preferably ends immediately against or in very close proximity to, the inferior surface of the top cap 12 , in line with the top cap line hole 31 , FIG. 2 . There is an annular seal, known as the upper piston seal 16 FIG. 2 , the inner wall of which preferably tightly fits around the exterior wall of the upper end of the piston tube 15 . The top surface of the annular upper piston seal 16 presses tightly against the inferior surface of the top cap 12 , and completely seals the surface around the periphery of the top cap line hole 31 .
Between the upper surface of the water vent magnet 19 and the water vent 17 and the inferior surface of bottom cap 14 surrounding the water vent 17 is preferably an annular seal, known as the water vent seal 18 , FIG. 2 . The inner wall of the annular water vent seal 18 fits tightly around the exterior wall of the piston tube 15 . The upper surface of the water vent seal 18 presses against the inferior surface of the bottom cap 14 , sealing the water vent 17 . The bottom of the water vent seal 18 presses against the top surface of water vent magnet 19 . There is preferably still space between the bottom surface of the water vent magnet 19 and underlying surface of the end cap 24 , FIG. 2 .
A coil spring known as the piston spring 20 , FIG. 2 , is preferably situated around the piston tube 15 , the base of the piston spring 20 preferably rests on the interior bottom surface of the bottom cap 14 in the open area between the ballast sockets 27 and the water vent 17 . The inner surfaces of the piston spring 20 preferably do not contact the piston tube 15 . An optional base plate 22 , FIG. 2 , is disc-shaped, with a central through-hole large enough to allow unfettered vertical movement of the piston tube 15 , which passes through it, and with fenestrations 40 , FIG. 3 , across its surface from top to bottom to allow water and air flow. The base plate 22 may be placed above any ballast sinkers 28 , noisemakers 29 , and the top surface of the ballast sockets 27 . The base plate 22 is preferably used when the outer diameter of the piston spring 20 is greater than the diameter of the open space between the ballast sockets 27 and the water vent 17 or the presence of any sinkers 28 or noisemakers 29 would interfere with the placement or movement of the piston spring 20 , FIG. 2 . The base of the piston spring 20 will preferably rest on the upper surface of the optional base plate 22 . The outer diameter of the base plate 22 will preferably fit inside the interior diameter of the tube body 13 , FIG. 2 .
In FIG. 2 an adjustable spring tensioner 21 preferably presses downward on the upper end of the piston spring 20 , partially compressing the piston spring 20 and securely gripping the external wall of the piston tube 15 at a level where the stored energy of the partially compressed piston spring 20 keeps the areas covered by the water vent seal 18 and the upper piston seal 16 leak proof. At this point the signal float 11 is fully buoyant and has a leak proof interior, FIGS. 2 , 6 , and 8 .
A fishing line 3 is able to be freely passed in a straight line through the top cap line hole 31 , the annular upper piston seal 16 , the inner diameter space of the piston tube 15 , the annular water magnet 19 , the magnet chamber 23 , and the end cap line hole 25 , FIG. 2 .
There are two ways the signal float 11 can preferably be rigged:
a) as a popping rigged signal float, FIGS. 10 and 11 , referred to as the signal float-popping 69 b) as a sliding rigged signal float, referred to the as signal float-sliding 70
In each case, the entire configuration composed of the signal float-popping or signal float-sliding and the bait assembly 90 constitutes bait fishing assembly 200 . In FIG. 10 , the signal float-popping 69 rig is preferably used to present the bait article 1 at a desired fixed depth which is preferably usually shorter than the height of the angler. In the signal float-popping 69 rig, the fishing line 3 is passed through the signal float 11 , and the magnetic trigger float 8 , to end secured to the hook eye 52 as previously described. In FIGS. 10 and 11 , the signal float 11 is preferably affixed to the fishing line 3 by pushing a conical peg 34 into the anchor hole 30 until the fishing line 3 is tightly pressed between the wall of the anchor hole 30 and the exterior wall of the conical peg 34 . The outer diameter of the narrow end of peg 34 is preferably smaller than the diameter of the anchor hole 30 . The outer diameter of the larger end of peg 34 is preferably at least the same, or greater, diameter as the anchor hole 30 . The length of peg 34 preferably is longer then the length of anchor hole 30 . The conical peg 34 preferably also has a through-hole running along its long axis, known as the peg line hole 35 . The point along fishing line 3 where peg 34 affixes the signal float 11 determines how deep the hook 2 impaled bait article 1 is suspended when the alarm system is deployed, FIG. 10 .
Another advantage of a popping rig is that fish attracting noise and water turbulence are created when the deployed rig is popped, or pulled sharply back toward the angler for a moment. The signal float-popping 69 is pulled at least partially sideways and the top surface of the signal float-popping 69 is at least partially submerged while being pulled through the water, creating noise and turbulence. Greater noise and turbulence can be achieved if at least part of the top surface of the signal float-popping 69 possess a depression or other drag or noise creating feature.
The deployment of the BARE HOOK/LOST BAIT ALARM SIGNAL FLOAT-POPPING rig, FIG. 10 is as follows:
a) The desired depth of the hook 2 is set by pinning the fishing line 3 at its appropriate point to the signal float-popping 69 preferably via the anchor hole 30 by peg 34 .
b) The bait article 1 is impaled onto the hook 2 .
c) The trigger float 8 is separated from the bottom of the signal float-popping 69 and brought down toward the hook 2 .
d) The bait anchor 6 is impaled into bait article 1 .
e) The angler uses the fishing pole/rod-reel to cast the alarm system into the water.
f) The signal float-popping 69 remains visible on the water surface 75 , similar to FIG. 6 .
g) The bait article 1 and attached hook 2 and attached magnetic trigger float 8 sink to the desired depth, similar to FIG. 6 .
When bait is removed from the hook 2 and the bait anchor 6 , the untethered magnetic trigger float 8 ascends freely along the fishing line 3 toward the bottom of the signal float-popping 69 and the water surface 75 , similar to FIG. 7 .
As the magnetic trigger float 8 reaches the bottom of the signal float-popping 69 , the magnetic attractive force between the trigger magnet 9 and the water vent magnet 19 becomes greater than the opposing force of the partially compressed piston spring 20 , similar to FIG. 7 .
This greater force causes the water vent magnet 19 and the attached piston tube 15 to move toward the end cap 24 carrying along with them the water vent seal 18 and the upper piston seal 16 , and further compressing the piston spring 20 by the affixed spring tensioner 21 , similar to FIG. 7 .
The displacement of the water vent seal 18 and the upper piston seal 19 opens the interior of the signal float-popping 69 to the entrance of water through the water vent 17 and the exit of air mostly or totally through the auxiliary air vent 32 as the peg 34 mostly blocks the passage of air through the top cap line hole 31 , similar to FIG. 7 .
Thus, the water vent magnet 19 and water vent seal 18 act as an automatic valve when triggered by the trigger float 8 . This automatic valve is thus magnetically operated, but it could be optically operated with modifications which would be apparent to one of ordinary skill in this art.
The loss of air from, and the filling with water into the signal float-popping 69 interior preferably causes the buoyancy of the signal float-popping 69 to decrease to the point where the signal float-popping 69 sinks beneath the water surface 75 , similar to FIG. 7 . The angler is now unable to see the signal float-popping 69 , notifying the angler to check if the hook 2 is bare or if there is a fish attached.
The speed of the sinking of the signal float-popping 69 , if observed by the angler, preferably will provide a clue, as a fish pulling on the hook 2 preferably will generally cause the signal float-popping 69 to sink at a faster rate.
The signal float-sliding 70 rig, FIGS. 1 , 2 , 4 , 5 , 6 , 7 , 8 , 9 , is usually used when the impaled bait article 1 is desired to be suspended at a water depth which is preferably greater than the depth that can be reached by a popping rig 69 (generally deeper than the height of the angler).
The BARE HOOK/LOST BAIT SIGNAL FLOAT-SLIDING rig, FIGS. 1 , 2 is composed of the following parts:
a) the fishing line 3
b) the signal float 11 and its component parts
c) the magnetic trigger float 8
d) any optional tackle such as a line connector 4 (for example, a swivel) and sinker 5
e) the hook 2
f) the tether line 7
g) the bait anchor 6
h) the bait article 1
The angler end of the fishing line 3 is affixed to whatever device/object the angler deems suitable, such as a fishing pole, rod/reel, rock, etc. The parts are arranged, aligned, and connected to each other as previously described.
Additional parts and arrangements needed for the BARE HOOK/LOST BAIT ALARM SIGNAL FLOAT-SLIDING rig FIGS. 1 , 2 , 6 , and 8 include:
i) the peg 34 which is situated above the signal float 11 , with the fishing line 3 freely passing through the peg line hole 35 before passing through the top cap line hole 31 , FIG. 2 . The peg 34 is too large to fit into the top cap line hole 31 .
ii) the depth setter 45 , which is preferably an object affixed to a point on the fishing line 3 above peg 34 and is too large to fit into the peg line hole 35 , FIG. 1 . The fishing line 3 does not move freely through the depth setter 45 . The depth setter 45 preferably is a very light weight flexible object such as a piece of rubber band or string which can be tightly knotted around or affixed in another way to the fishing line 3 and be wound onto a reel without difficulty. The length of fishing line 3 below its fixation point with the depth setter 45 determines the depth that will be reached by the hooked bait article 1 . The depth setter 45 is preferably adjustable along the length of fishing line 3 above the peg 34 .
iii) the tether ring 38 , FIG. 3 , which preferably fits tightly around the walls of the magnet chamber 23 and provides an attachment point for the spacer tether 37 , FIG. 3 . The tether ring 38 may be replaced by any other means of attachment between the signal float-sliding 70 and the spacer tether 37 .
iv) the spacer tether 37 , which is preferably a line or thin ribbon of flexible light weight material which is affixed to the tether ring 38 on one end and the casting spacer 36 , FIG. 3 , on the other end.
v) the casting spacer 36 , FIG. 1 , which is preferably a tubular object with a lengthwise section removed completely from end to end, forming a slot, known as the spacer line slot 39 , FIG. 1 . The casting spacer 36 is preferably composed of a buoyant material.
The casting spacer 36 is preferably affixed to the spacer tether 37 on its upper end directly across from the spacer line slot 39 .
The signal float-sliding alarm system, FIG. 1 is preferably set and deployed in the following manner:
To be baited and cast, the signal float-sliding 70 preferably has to be kept separated from the magnetic trigger float 8 . Before the bait article 1 is affixed to the hook 2 , the peg 34 , which has the fishing line 3 passing through it, is inserted into the anchor hole 30 , FIG. 4 , which causes the part of fishing line 3 , exiting the narrow end of the peg line hole 35 , to be folded and tightly squeezed and affixed between the wall of anchor hole 30 and the outer wall of peg 34 , FIG. 4 . The signal float-sliding 70 is now temporarily fixed to the fishing line 3 . There is a length of fishing line 3 between the bottom of the signal float-sliding 70 and the magnetic trigger float 8 preferably sufficient to keep the magnetic attraction between them to a negligible amount, FIG. 4 . The bait article 1 is now impaled onto the hook 2 . The bait anchor 6 is now impaled into the bait article 1 . The magnetic trigger float 8 is now tethered to the bait article 1 by the tether line 7 , FIG. 4 .
After being baited, the signal float-sliding rig must be readied to be cast, FIG. 5 . This is preferably done by pushing the peg 34 back out of the anchor hole 30 , enabling sliding to occur between the signal float-sliding 70 and the fishing line 3 . Before any sliding occurs, the casting spacer 36 is placed lengthwise between the bottom of the signal float-sliding 70 and the top of the magnetic trigger float 8 . The fishing line 3 reaches the interior space of the casting spacer 36 through the spacer line slot 39 where it is freely movable. The signal float-sliding 70 and the in-line casting spacer 36 are now moved along the fishing line 3 until the bottom of the casting spacer 36 presses against the top of the magnetic trigger float 8 , due to the weight of the signal float-sliding 70 resting on top of the casting spacer 36 , FIG. 5 . The signal float-sliding alarm system is now ready to be cast into the water.
After being cast into the water, a series of events occur to fully deploy the BARE HOOK/LOST BAIT ALARM SIGNAL FLOAT-SLIDING rig, FIG. 6 , which are as follows:
1) The buoyant signal float-sliding 70 stays visible on the water surface 75 , FIG. 6 .
2) The bait article 1 , hook 2 , any tackle such as the line connector 4 and sinker 5 , magnetic trigger float 8 , and fishing line 3 descend from the water surface 75 , FIG. 6 .
3) As the magnetic trigger float 8 descends, the buoyant casting spacer 36 is preferably freed, and being buoyant, moves away from under the end cap 24 , away from the fishing line 3 by means of the spacer line slot 80 , toward the water surface 75 , FIG. 6 .
4) There is no longer any obstruction between the end cap 24 and the magnetic trigger float 8 , FIG. 6 .
5) The descending fishing line 3 slides downward through the signal float-sliding 70 until the affixed depth setter 45 preferably meets peg 34 and pushes peg 34 against the top cap 12 , FIG. 6 . The descent of fishing line 3 now ceases, presenting the hooked bait article 1 at the desired depth, FIG. 6 .
After the bait article 1 is removed from the hook 2 and the bait anchor 6 , the magnetic trigger float 8 preferably floats upward along the fishing line 3 until contacting the bottom of the end cap 4 , FIG. 7 .
The loss of buoyancy and sinking below the water surface 75 of the signal float-sliding 70 now preferably occurs in the same way as previously described for the signal float-popping 69 , alerting the angler, FIGS. 7 , and 9 .
Another embodiment of the BARE HOOK/LOST BAIT ALARM, replaces the signal float 11 with a lighted float known as the beacon float 53 . The beacon float 53 , FIGS. 12 , 13 , 14 , 15 , and 16 , consists of the following parts:
1) a one-end open tube 54 , FIG. 13 which is preferably transparent or translucent
2) a transparent or translucent cap 55 , FIG. 13 which preferably closes the one-end-open tube 54 in a leak proof fashion, forming a leak proof housing known as the electronics housing 59 , FIG. 12 .
3) a buoyant jacket, known as the flotation jacket 56 , FIG. 12 , preferably surrounds and tightly grips a circumferential section, or mostly circumferential section, of the exterior wall of the electronics housing 59 when the electronics housing 59 is inserted into the inner hollow space of the flotation jacket 56 . The flotation jacket 56 can be shaped similar to a horizontal C or O, with an interruption in its wall, from its exterior surface to its interior surface, known as the jacket line slot 51 , FIG. 13 . A separate through-hole, known as the jacket line guide 50 , FIG. 13 preferably extends from the upper surface to the lower surface of the flotation jacket 56 .
4) Surrounding and tightly gripping a lower portion of the electronics housing 59 is a ring, known as the ring stop 60 , FIG. 17 . A through-hole from the upper surface to the bottom surface of ring stop 60 , is known as the ring stop line guide 61 , FIGS. 12 and 13 . A flexible closed slit from the exterior sidewall of ring stop 60 into the interior of the ring stop line guide 61 may exist to allow the fishing line 3 to enter the ring stop line guide 61 from the side. At least a part of a magnetically attractive object known as the magnet captor 62 , FIGS. 12 , 13 , 14 , 15 , 16 , and 17 is located on the inferior surface of the ring stop 60 in close proximity to the ring stop line guide 61 and the exterior wall of the electronics housing 59 . The magnet captor 62 may also extend above the ring stop 60 .
The interior of the beacon float 53 , FIGS. 12 and 13 contains the following:
5) a circuit board 65 preferably containing a battery 66 , a magnetic reed switch 67 which is normally closed in the absence of a magnetic field, and preferably two light emitting devices, such as LED chips or lamps, with one directed above the water surface, visible to the angler, known as the angler beacon 63 , FIGS. 13 and 16 , and the other, known as the attractor beacon 64 , FIGS. 13 and 16 , whose emitted light is primarily visible below the water surface. The circuit board 65 also contains all the other parts and connected circuitry to enable proper functioning of all the parts, which would be known to those skilled in the art. (A schematic, FIG. 22 , is included.)
6) a line, known as the retrieval line 68 , FIGS. 12 and 13 , which is affixed on one end to the circuit board, the other end and the rest is positioned to be acquired and pulled upon when the circuit board is required to be removed from the open beacon float electronics housing 59 , such as when the battery needs to be replaced.
7) If desired, insulated ballast (sinkers), not shown, may be placed in the lower part of the electronics housing, or affixed to the exterior of the electronics housing 54 or the tether ring 60 or the float jacket 56 , in a manner that does not greatly interfere with the attractor beacon 64 .
The beacon float 53 can be rigged in two ways to form THE BARE HOOK/LOST BAIT ALARM BEACON FLOAT SYSTEM
1) as a popping float, known as the beacon float-popping rig 71 , FIG. 16 , and
2) as a sliding float, known as the beacon float-sliding 72 rig, FIGS. 12 , 13 , 14 , and 15
In each configuration, the entire assembly composed of the bait assembly 90 plus the beacon float-popping 71 or beacon float-sliding 72 constitutes bait fishing assembly 210 . To be rigged in the beacon float-popping 71 manner, FIG. 16 , the fishing line 3 is passed through the jacket line slot 51 into the interior space of the flotation jacket 56 . The electronics housing 59 is inserted into the interior space of the flotation jacket 56 until the fishing line 3 is tightly pressed and held immobile between the interior wall of the flotation jacket 56 and the exterior wall of the electronics housing 59 . The length of fishing line 3 between this fixation point and the attached hook 2 , determines the submerged depth of the hooked bait article 1 .
Optional friction bands FIG. 17 , which are stretchable and durable, can be placed around either the electronics housing 59 , known as the housing friction band 57 , or the flotation jacket, known as the jacket friction band 58 , or both to increase the holding power between the electronics housing 59 , the fishing line 3 , and the jacket 56 . The fishing line 3 then passes through the ring stop line guide 61 , FIG. 16 .
A distance below the ring stop 60 , the fishing line 3 preferably passes through the magnetic trigger float 8 , any line connector 4 (such as a swivel) and any optional sinker 5 , till the end of fishing line 3 affixes to the hook 2 , FIG. 16 .
The bait article 1 is impaled onto the hook 2 , FIG. 16 .
The bait anchor 6 is impaled into the bait article 1 , tethering the magnetic trigger float 8 to the bait article 1 preferably via the tether line 7 , FIG. 16 .
The distance between the trigger magnet 9 and the magnetic reed switch 67 is preferably great enough to keep the magnetic field of the trigger magnet 9 from influencing the magnetic reed switch 67 . The electric circuit is normally closed allowing light to be emitted from the angler beacon 63 and attractor beacon 64 , FIG. 16 .
To be rigged in the beacon float-sliding 72 manner, FIGS. 12 , 13 , 14 , and 15 , a tether ring 38 is preferably added above the ring stop 60 , tightly fitting to the exterior wall of the electronics housing 59 . The ring stop 60 may also serve as a substitute tether ring 38 , FIG. 12 .
A flexible tether line or ribbon, known as the spacer tether 37 , attaches to the tether ring 38 on one end and to a casting spacer 36 , on the other end.
The fishing line 3 is preferably passed though the peg line hole 35 of the peg 34 , FIG. 12 . A depth setter 45 is affixed to the fishing line 3 preferably above the peg 34 , between the fish-ing pole/rod-reel 43 . and the peg 34 , FIG. 12 .
Then the fishing line 3 is preferably passed through the top surface of the flotation jacket 56 through the jacket line guide 50 , and out from the bottom of the flotation jacket 56 , FIG. 12 .
The fishing line 3 next passes through the ring stop line guide 61 , FIG. 12 . The casting spacer 36 is placed under the bottom of the beacon float-sliding 72 and the fishing line 3 slides through the spacer line slot 39 to the interior space of the casting spacer 36 and out through the bottom end of the casting spacer 36 .
The fishing line 3 then preferably continues down through the magnetic trigger float via the connecting tube 10 . The fishing line 3 then exits the bottom of the magnetic trigger float 8 , continuing through any optional sinkers 5 and any line connector 4 . The fishing line 3 terminates by being affixed to the hook eye 52 of hook/jig-head hook 2 .
The beacon float-sliding 72 rests on top of the casting spacer 36 , FIG. 12 . The bottom of the casting spacer 36 rests on top of the magnetic trigger float 8 , similar to FIG. 5 .
The bottom of trigger float 8 , preferably rests on either an optional sinker 5 , a line connector 4 , or the hook eye 52 , similar to FIG. 5 , FIG. 12 .
The bait article 1 is affixed to the hook 2 , FIG. 12 .
The bait anchor 6 is impaled into the bait article 1 , anchoring the magnetic trigger float 8 to the bait article 1 via the tether line 7 , FIG. 12 .
The beacon float-sliding rigged BARE HOOK/LOST BAIT ALARM, is now ready to be cast into the water.
The casting sequences of the beacon float-popping rig and the beacon float-sliding rig mimic the casting sequences of the respective signal float-popping rig 69 and the signal float-sliding rig 70 .
For both beacon float rigs, FIGS. 14 , 15 , and 16 .
After the bait article 1 , is removed from the hook 2 , FIG. 15 , and the bait anchor 6 , the magnetic trigger float 8 is able to freely ascend along the fishing line 3 until the magnetic trigger float 8 reaches the ring stop 60 . The trigger magnet 9 is attracted to and affixes to the magnet captor 62 , which holds the trigger magnet 9 in close enough proximity to the magnetic reed switch 67 , located in the waterproof electronics housing 59 , to enable the magnetic field of the trigger magnet 9 to influence the magnetic reed switch 67 . As a result the normally closed circuit becomes open, cutting off the electrical current to the angler beacon 63 and the attractor beacon 64 , FIG. 15 . The resulting loss of light emission notifies the angler to see if the hook 2 is bare, FIG. 15 .
The circuitry and electronics could be modified so that only the angler beacon 63 is turned off and the attractor beacon 64 continues to emit light when the magnetic reed switch 67 changes from closed to open.
The color of the emitted light from the beacon float 53 above the water surface 75 preferably is one that is best seen by the human eye at night (for example, white) or that does not hamper human vision at night (for example, red or green).
The color of the light emitted from the beacon float 53 below the water surface preferably is one that is easily seen by the fish and is also non-threatening, such as green.
The beacon float 53 could also have only an angler beacon 63 which may also function, if only partially, as an attractor beacon 64 .
A suitable lighted beacon float schematic is shown in FIG. 22 . The detector switch S 1 preferably consists of any electromechanical device that detects the bait article 1 has been released. The detector switch S 1 is a normally closed magnetic reed switch. The switch S 1 allows current to flow from the battery B 1 , to the circuit. When bait article 1 is released, a cascade of events occur, which results in the switch S 1 opening and thereby interrupting the current flow.
Integrated circuit U 1 and inductor L 1 comprise a boost converter. The boost converter boosts the nominal 1.5V battery voltage to a voltage that is appropriate to forward bias the two parallel connected LEDs, LED1 and LED2, determined by the forward on voltage of the LEDs. This particular boost converter regulates the boost current. The output voltage is determined by the forward on voltage of the LEDs. The boost converter provides the boost current by switching the current through L 1 at a high frequency rate. In this particular implementation, the switching frequency is preferably approximately 500 kHz. The value of L 1 preferably determines the forward bias current to the LEDs.
Capacitor C 2 enhances the circuit performance by lowering the high frequency impedance of the battery. C 2 is not essential to the function of this circuit. C 2 has the effect of extending battery life by lowering the battery impedance on a pulse by pulse basis.
Diode D 1 (e.g. a parallel connected Schottky-type) with the filter capacitor C 1 further enhance the circuit performance by minimizing the peak pulse current to the LEDs. The output from the boost converter circuit is preferably a series of pulses. These pulses may exceed the peak current of certain LEDs that may be used. The D 1 and C 1 filter circuit converts these pulses to an average current level of a lower level. D 1 and C 1 are not essential components for the function of this circuit. The use of these components depends on the specific boost convert type and LEDs selected.
LED1 and LED2 are preferably light emitting diodes. This circuit shows the LEDs in parallel however, depending on the type of LEDs selected, the LEDs may be connected in series.
A transmitter can be used to signal the angler preferably with an alarm (e.g., sound, vibration, etc.). A transmitter such as shown in FIG. 23 could be employed. This can be used by itself or with, for example, the LEDs of FIG. 22 . The detector consists of any electromechanical device that detects the bait article 1 has been released. The detector can be a magnetic reed switch. The output of the detector is a signal that starts the timer in the encoder circuit.
The duty cycle senses the output from the detector. The duty cycle timer provides an enabling signal out to the encoder. The duty cycle determines the length of time between transmit bursts. The duty cycle limit is a regulatory requirement for low power, unlicensed transmitters.
The encoder is enabled by the output signal from the duty cycle timer. The encoder is preferably a user programmable serial shifter register pulse generator that allows the user to select one of N identity codes. N can be any number without limit but typically will be between 2 6 and 2 10. The output of the encoder is a series of pulse, N bit long. The RF transmitter can be any RF signal source with modulator. In the simplest case the transmitter may be only a single transistor oscillator modulated directly by the encoder to provide on-off keying (OOK).
The output of the transmitter is connected to an antenna. In the system of the present invention, the antenna can be a simple wire monopole; however any antenna may be used provided the overall transmitter complies with the regulations for unlicensed transmitters.
The receiver is shown in the diagram of FIG. 24 . The RF receiver can be any receiver circuit that is compatible with the transmitter. The receiver can be a simple AM receiver that detects the OOK and provides a pulse output.
The decoder is preferably a serial shift register and comparator that is user programmable with one-of-N identity codes. N can be any number without limit but typically will be between 2 6 and 2 10. The user selects an identity code that matches the code in the transmitter. If the decoder detects a match, an output signal pulse occurs.
The timer preferably conditions the decoder output by extending the pulse length to provide a suitable signal to the enunciator. The timer is also used to set the length of time the receiver circuits are one. The timer duty cycle is set so as to conserve battery power in the portable implementation.
The enunciator can be any signal device such as a tone alert, vibration, or flashing light.
The simplest embodiment of the invention, FIGS. 18 and 19 , uses anon magnetic trigger float 8 to signal the angler. This embodiment is used when the angler wishes to flat line rig, meaning there is no float normally on the water surface 75 , FIG. 18 . When the bait article 1 is removed from the hook 2 and the bait anchor 6 , the non-magnetic trigger float 8 is freed and travels upward along the fishing line 3 to the water surface 75 , FIG. 19 . The trigger float 8 is now visible to the angler, FIG. 19 , alerting the angler to the need to rebait the hook 2 .
In another embodiment of the invention, FIGS. 25 , 26 , 27 , 31 , 32 , 36 , 37 , 38 , 39 , 40 , 41 , 42 and 43 , some previously described parts are modified, removed, relocated and some parts are added. FIGS. 25 , 26 , 36 , 37 , 38 , 39 , and 41 all display a sinking float 100 . The complete configuration which utilizes sinking float 100 plus bait assembly 90 is referred to as bait fishing assembly 220 and can be seen in FIGS. 36-39 and 41 . FIG. 44 displays a simplified sinking float 110 and FIG. 45 displays a simplified sinking float 120 . The entire assembly incorporating simplified sinking float 110 plus bait assembly 90 constitutes bait fishing assembly 230 . The entire assembly incorporating simplified sinking float 120 plus bait assembly 90 constitutes bait fishing assembly 240 . Parts that are removed are the upper piston seal 16 , the piston spring 20 , the spring tensioner 21 , and the base plate 22 . The piston seal guide 46 , is modified by shrinking its inner diameter until it is slightly greater than the outer diameter of the piston tube 15 , leaving intact the unrestricted vertical movement of the piston tube 15 . The piston seal guide 46 , becomes the piston guide 77 , FIG. 39 , and keeps the piston tube 15 , oriented vertically in line with the top cap line hole 25 , The piston spring 20 and the spring tensioner 21 are removed. In their place is an annular magnet known as the tube body magnet 76 , FIGS. 36 , 39 , and 42 , which is located on the interior bottom surface of the bottom cap 14 . The piston tube 15 passes freely through the interior space of the tube body magnet 76 .
The polarity of the tube body magnet 76 is oriented to attract the water vent magnet 19 and press the water vent seal 18 around the water vent 17 , sealing the water vent 17 to prevent the flooding of water into the signal float 100 , FIGS. 26 , 36 , 41 , and 42 . When the trigger float magnet 9 is in close proximity to the exterior bottom surface of the end cap 24 , the magnetic attraction between the trigger float magnet 9 and the water vent magnet 19 is great enough to pull the water vent magnet 19 away from the tube body magnet 76 towards the interior bottom surface of the end cap 24 , FIG. 37 . This downward displacement also moves the piston tube 15 and the water vent seal 18 downward, allowing water to pass through the water vent 17 into the interior of the signal float 11 , FIG. 37 .
Either the water vent magnet 19 or one of the other magnets the tube body magnet 76 or the trigger float magnet 9 , may be replaced by less expensive ferrous, magnetically attracted material in annular shape as long as the same balance of attractions and movements are retained.
The anchor hole 30 is relocated to the central top of the plateau 47 surrounding the top cap line hole 31 and is renamed the anchor socket 80 , FIG. 25 . The sides of the plateau 47 are now not fenestrated.
A double peg 79 , FIGS. 27 , 28 and, 36 , replaces the single peg 34 , FIGS. 29 and 30 , when rigging the signal float 11 in the popping configuration 69 , FIGS. 36 , 37 , and 40 . The double peg 79 is shaped like two single pegs 34 parallel to each other and connected by a bridge between the wide end of each peg; one of the legs of the double peg 79 , fits into the anchor socket 80 and pinches the fishing line against the walls of the double peg 79 leg and the anchor socket 80 , FIG. 40 , which sets the depth of the hook 2 . The other leg of the double peg 79 fits into one of the light sockets 33 , FIG. 40 and provides extra holding power to prevent unwanted displacement of the double peg 79 .
The auxiliary vent hole 32 is relocated to the flat surface to the side and below the plateau 47 and enters the interior of the signal float 11 , FIG. 43 . There may be one or more auxiliary vent holes 32 , FIG. 43 .
The chamber vents 74 in the magnet chamber walls 73 may be replaced by solid walls. The cap vents 26 may be relocated to the bottom of the end cap 24 and positioned peripherally around the end cap line hole 25 , FIG. 26 . There may be one or more cap vents 26 .
In another embodiment, FIG. 44 , the invention is further simplified by merging the top cap 12 and the tube body 13 into a single piece known as the float body 81 .
Either one or both of the light sockets 33 may be eliminated. The double peg 79 may be eliminated, reverting back to using the single peg 34 in the popping configuration, FIG. 44 .
The ballast sockets 27 may be eliminated, FIG. 44 . Ballast sinkers 28 may be small enough to not interfere with the piston tube 15 's vertical movement and may serve double duty as noisemakers since they are now free to bounce around the interior of the signal float.
A small float, similar to the trigger float 8 is added to the interior top of the float body 81 . This float material forms a friction fit with the peg 34 in the popping float configuration of the sinking float, FIG. 44 , and is known as the peg anchor 82 . The peg anchor 82 also serves to replace the piston guide 77 , as the piston tube 15 can use the central hole 83 of the peg anchor 82 as a guide, FIG. 44 .
The peg anchor 82 may be held securely in place against the downward force experienced when the peg 34 is pushed into the peg anchor 82 by a locking collar 84 , FIG. 44 . The locking collar 84 is a tubular segment of semi-rigid material which may have a lengthwise longitudinal gap in one segment of its wall. The locking collar 84 fits tightly against the peg anchor 82 and the interior walls of the float tube body 81 , FIG. 44 . The longitudinal slit allows the locking collar 84 to change its inner and outer dimensions so as to be able to be used in different inner diameter float bodies 81 . The anchor socket 80 totally absorbs the top cap line hole 31 and may be shorter becoming more of an anchor/line hole 85 than a socket, FIG. 44 .
An auxiliary vent hole 32 , one or more, may be located peripheral to the anchor/line hole 85 , which will communicate with the interior of the float tube body 78 . Longitudinal vent tunnels may also be located on the peg anchor 82 to allow communication with the main interior of the float tube body. The peg line hole 35 may also allow for the transit of air between the atmosphere and the interior of the float tube body in the popping float configuration, FIG. 44 .
There may be an upper extension of the outer walls of the float body 81 past the top surface. This extension will turn the upper surface of the float body 81 into a cup-like depression known as the popping chamber 86 , FIG. 44 . The walls of the popping chamber 86 may be slotted or fenestrated to allow water to easily escape after the popping maneuver.
This simplified sinking signal float embodiment 110 , FIG. 44 , shown in the popping configuration, may also be rigged as a sinking signal float in a sliding configuration (not shown). In the sliding configuration, the rigging would be similar to FIGS. 38 , 39 , and 41 , including the depth setter 45 and casting spacer 36 .
FIG. 45 shows a simplified sinking signal float 120 , similar to that shown in FIG. 44 , but it additionally includes a piston tube coupler 87 .
In all the sinking float embodiments, if there were to be differing sizes, small, medium and large, etc., there could be interchangeable parts for each size. For example, parts from the small size float such as the bottom cap 14 , end cap 24 , tube body magnet 76 , water vent seal 18 , water vent magnet 19 , piston tube 15 , trigger magnet 9 , trigger float 8 , tether line 7 , bait anchor 6 , casting spacer 36 , peg 34 , double peg 79 could be used in the other corresponding sizes. For the shorter piston tube 15 , one would add a piston tube coupler 87 , and another proper length of piston tube to increase length. One could also add a piston tube coupler 87 to the surface float shown in FIGS. 1-11 and 25 - 44 so that the float sizes can be interchangeable from small to medium to large as well. Also, the lengths of the exterior tube of the float can be changed in the same manner (by adding a coupler and another section). Also, one could use a corrugated accordion-style piston tube and/or a corrugated accordion-style exterior tube to alter length.
The float shown in FIGS. 18 and 19 (and the trigger floats 8 in other figures) is preferably sized such that its buoyancy is overcome by the impaled bait, the hook, or their combination.
All signal float embodiments may have spaces suitable for logos, advertisements, names, photos, and other printed materials and decals of suitable materials for a marine and outdoor environment. For example, but not limited to, a photo of a newborn baby's face could be incorporated into a pirate costume decal with suitable congratulation phraseology and be applied to the signal float and handed out to people instead of the traditional cigars.
PARTS LIST:
Part Number
Description
1.
bait article
2.
hook
3.
fishing line
4.
line connector
5.
sinker
6.
bait anchor (may be barbed)
7.
tether line
8.
trigger (first) float
9.
trigger magnet
10.
connecting tube
11.
signal (second) float
12.
top cap
13.
tube body
14.
bottom cap
15.
piston tube
16.
upper piston seal
17.
water vent
18.
water vent seal
19.
water vent magnet
20.
piston spring
21.
spring tensioner
22.
base plate
23.
magnet chamber
24.
end cap
25.
end cap line hole
26.
cap vents
27.
ballast sockets
28.
ballast sinkers
29.
noisemakers
30.
anchor hole
31.
top cap line hole
32.
auxiliary vent hole
33.
light socket
34.
peg
35.
peg line hole
36.
casting spacer
37.
spacer tether
38.
spacer tether ring
39.
spacer line slot
40.
fenestrations
41.
hook line guide
42.
slide stoppers
43.
fishing pole/rod-reel
44.
light stick
45.
depth setter
46.
piston seal guide
47.
plateau
48.
trigger float line hole
49.
trigger magnet line hole
50.
jacket line guide
51.
jacket line slot
52.
hook eye
53.
beacon float
54.
one-end-open tube
55.
cap
56.
flotation jacket
57.
housing friction band
58.
jacket friction band
59.
electronics housing
60.
ring stop
61.
ring stop line guide
62.
magnet captor
63.
angler beacon
64.
attractor beacon
65.
circuit board
66.
battery
67.
magnetic reed switch - normally closed
68.
retrieval line
69.
signal float - popping
70.
signal float - sliding
71.
beacon float -popping
72.
beacon float - sliding
73.
magnet chamber walls
74.
chamber vents
75.
water surface
76.
tube body magnet
77.
piston guide
78.
tube body
79.
double peg
80.
anchor socket
81.
float body
82.
peg anchor
83.
central hole
84.
locking collar
85.
anchor/line hole
86.
popping chamber
90.
bait assembly
100.
sinking float
110.
simplified sinking float
111.
signal float
120.
simplified sinking float
200.
bait fishing assembly
210.
bait fishing assembly
220.
bait fishing assembly
230.
bait fishing assembly
240.
bait fishing assembly
All measurements disclosed herein are at standard temperature and pressure, at sea level on Earth, unless indicated otherwise. All materials used or intended to be used in a human being are biocompatible, unless indicated otherwise.
The foregoing embodiments are presented by way of example only; the scope of the present invention is to be limited only by the following claims. | A bait and hook arrangement is coupled with a mechanism that alerts a fisherman when his or her bait article is no longer attached to the hook. When the bait is off the hook, (empty hook), the mechanism is triggered. | 0 |
CROSS REFERENCE TO RELATED APPLICATIONS
This application is the US National Stage of International Application No. PCT/EP2004/009964, filed Sep. 7, 2004 and claims the benefit thereof. The International Application claims the benefits of European Patent application No. 03020720.3 filed Sep. 11, 2003. All of the applications are incorporated by reference herein in their entirety.
FIELD OF THE INVENTION
The invention relates to a gas turbine with a rotationally fixed inner casing which is arranged concentrically with respect to the rotor, according to the claims, and to an annular sealing means for a gas turbine, according to the claims.
BACKGROUND OF THE INVENTION
Such a gas turbine is known from EP 1 118 806 A1. A freely projecting flexural extension is provided for sealing off a gap delimited by two partially overlapping wall segments. Under thermal action, the flexural extension flexes in such a way that it closes the gap.
EP 896 128 discloses a sealing element for a gas turbine. The gas turbine has a guide blade ring consisting of adjacent turbine guide blades which form an annular hot-gas duct. Platforms are arranged on the turbine blades for the inner and outer delimitation of the hot-gas duct. Directly adjacent platforms form, with their end faces lying against one another, a gap which is sealed off by means of a sealing element. For this purpose, a groove is introduced in each case in each end face, said grooves lying opposite one another and the sealing element being inserted into them. The sealing element, of C-shaped cross section, projects in each case with one of the two bent ends into a groove in such a way that the two arms of the sealing element which extend transversely with respect to the groove bottom bear in each case against a flank of the groove and thus seal off the gap between the two adjacent platforms. The working fluid flowing in the hot-gas duct is thus prevented from leaving the duct through the gap.
Furthermore, a sealing element is known from DE 100 44 848, which seals off a gap formed between two static turbine parts. The sealing element is likewise inserted in two grooves lying opposite one another, but, in contrast to EP 896 128, has a different geometry. The action and function of this sealing element are identical to those of the abovementioned sealing element.
When the gas turbine is in operation, thermal expansions arise on the components acted upon by hot gas, such as the guide blades and their platforms, and may lead to a displacement of the components with respect to one another.
In the case of a shear displacement directed parallel to the gap, the known sealing elements allow only relatively small displacement travel.
SUMMARY OF THE INVENTION
The object of the invention is, therefore, to specify a sealing means for a gas turbine, which is effective even in the case of greater displacement travel. The object is, furthermore to specify a gas turbine appropriate for this purpose.
The object is achieved, with respect to the gas turbine, by means of the features of the claims and, with respect to the sealing means, by means of the features of the claims.
The solution for achieving the object proposes, with respect to the gas turbine, that the sealing means be designed as a spring element with a first end, with a second end and with a spring region lying between them, and that the first end be secured in one of the two rings in a circumferential groove open toward the annular gap, and that the collar arranged on the other of the two rings have, for the second end of the spring element, an annular bearing surface, against which the spring element bears, prestressed, so as to seal off the annular gap, while, in order to generate the prestress, the spring region is supported on an annular supporting surface which is provided on the collar of the one ring and which faces the annular bearing surface.
When the gas turbine is in operation, the two rings move in relation to one another on account of thermal expansions. These movements are parallel to the annular bearing surface, perpendicular thereto or a mixture of the two movements. In this case, the spring prestress causes the automatic follow-up of the spring element on the annular bearing surface, without the spring element losing contact with the annular bearing surface and the spring element thus losing the sealing action. Only the contact line is displaced in the axial direction along the annular bearing surface.
In order to generate the spring prestress, the spring element utilizes as an abutment an annular supporting surface which is arranged on the inside, facing the hot-gas duct, of the outer collar. In this case, the spring element bears at least partially between its two ends against the abutment. The sealing action can be maintained, since, as a result of the support of the spring element, the free or second end can follow especially high radial displacements, that is to say, even when the gap dimension increases appreciably, the sealing action remains maintained.
Since the spring element has an elongate configuration in cross section, a greater shear displacement, that is to say in the radial direction with respect to the rotor, of the two components in relation to one another is possible.
Advantageous embodiments are specified in the subclaims.
Expediently, the inner casing is designed to diverge conically toward the rotor in the flow direction.
A simple overlapping of the collars arranged on the adjacent rings and extending in the direction of divergence is afforded when the front wing, as seen in the flow direction, has the radially inner collar and the rear ring has the outer collar, so that, as seen radially, the annular gap runs counter to the flow direction of the working fluid. This arrangement impedes the deeper inflow of the hot gas into the gap to be sealed off, since the hot gas loses kinetic energy during penetration as a result of the reversal in flow direction brought about by a bend at right angles. The spring element is thus acted upon by the hot gas solely by a lower radially outward-directed force than the spring prestress.
For this purpose, the fixed end of the spring element is introduced as fixed bearing in a circumferential groove provided on the end face of the rear ring and can be connected, gas-tight, to the rear ring by welding or soldering. During movements, therefore, the spring element always co-moves in synchronism with the rear ring.
In a further embodiment, the annular bearing surface is provided on that side of the radially inner collar which faces away from the working fluid and therefore on the front ring. The spring element, of S-shaped cross section, can then bear sealingly as a free bearing with its free end against the annular bearing surface.
Especially advantageous is the embodiment in which, outside the inner casing, a cooling medium can flow, the pressure of said cooling medium being higher than the pressure of the working fluid inside the inner casing, and in which the spring action of the sealing means runs in the direction of the pressure drop. As a result, the spring action of the spring element is assisted by the appreciable pressure drop between the cooling medium and working fluid. The additional pressure force thus generated is dependent on the area of the spring element on which the cooling medium can act and becomes higher with a rising pressure difference. The additional pressure force leads to an improved sealing action. Even in the event that the spring prestress diminishes, a reliable bearing of the free end of the spring element against the annular bearing surface is thus ensured during operation.
The solution for achieving the object proposes, with respect to the sealing means for a gas turbine, which seals off a gap delimited by two directly adjacent components which in each case have a collar in the region of the gap and therefore partially overlap one another, that the sealing means be designed as a spring element with a first end, with a second end and with a spring region lying between them, and that the first end be secured in one of the two components in a groove open toward the gap, and that the collar arranged on the other of the two components have, for the second end of the spring element, a bearing surface against which the spring element bears, prestressed, so as to seal off the gap, while, in order to generate the prestress, the spring region is supported on a supporting surface which is provided on the collar of the one component and which faces the bearing surface.
BRIEF DESCRIPTION OF THE DRAWINGS
The advantages described with regard to the gas turbine in this case also apply accordingly to the sealing means.
The invention is explained by means of drawings in which:
FIG. 1 shows an annular gap with a sealing means,
FIG. 2 shows a part longitudinal section through a gas turbine, and
FIG. 3 shows the annular gap according to FIG. 1 with offset rings,
FIG. 4 shows the annular gap according to FIG. 3 after calking of the circumferential groove.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 2 shows a gas turbine 1 in a part longitudinal section. It has, inside it, a rotor 3 which is rotationally mounted about an axis of rotation 2 and which is also designated as a turbine rotor or rotor shaft. An intake casing 4 , a compressor 5 , a toroidal annular combustion chamber 6 with a plurality of coaxially arranged burners 7 , a turbine 8 and an exhaust gas casing 9 succeed one another along the rotor 3 .
In the compressor 5 , an annular compressor duct 10 is provided, which narrows in cross section in the direction of the annular combustion chamber 6 . At the outlet, on the combustion chamber side, of the compressor 5 , a diffuser 11 is arranged, which is flow-connected to the annular combustion chamber 6 . The annular combustion chamber 6 forms a combustion space 12 for a mixture consisting of a fuel and of compressed air. A hot-gas duct 13 is flow-connected to the combustion space 12 , the hot-gas duct 13 being followed by the exhaust gas casing 9 .
Blade rings are in each case arranged alternately in the compressor duct 10 and in the hot-gas duct 13 . A guide blade ring 15 formed from guide blades 14 is followed in each case by a moving blade ring 17 formed from moving blades 16 . The fixed guide blades 14 are in this case connected to a guide blade carrier 18 , whereas the moving blades 16 are connected to the rotor 3 by means of a disk 19 .
The guide blades 14 are fastened to the guide blade carrier 18 and at their end facing the guide blade carrier 18 have platforms 21 which outwardly delimit the hot-gas duct 13 . Arranged adjacently to the platforms 21 of the guide blades 14 in the flow direction are guide rings 22 which lie opposite the tips of the moving blades 16 and which delimit the hot-gas duct 13 . The platforms 21 of the individual guide blades 14 of a guide blade ring 15 in this case form a ring 25 which is adjacent to the guide ring 22 consisting of segments and between which an annular gap 23 is enclosed. The guide ring 22 and the platform ring in this case form an inner casing 37 for the working fluid 20 flowing through the rings.
While the gas turbine 1 is in operation, air 21 is sucked in by the compressor 5 through the intake casing 4 and is compressed in the compressor duct 10 . Air L provided at the burner-side end of the compressor 5 is led through the diffuser 11 to the burners 7 and is mixed there with a fuel. The mixture is then burnt in the combustion space 10 so as to form a working fluid 20 . The working fluid 20 flows from there into the hot-gas duct 13 . At the guide blades 14 arranged in the turbine 8 and at the moving blades 16 , the working fluid 20 expands so as to transmit pulses, so that the rotor 3 is driven and, with it, a working machine (not illustrated) coupled to it.
FIG. 1 shows a detail of the gas turbine 1 with a gap, for example an annular gap 23 . The annular gap 23 is in this case formed between a first component, the platform 21 of the guide blade 14 , and a second component, the guide ring 22 . FIG. 1 illustrates only the components essential to the invention, that is to say the illustration of guide blades 14 and moving blades 16 and of the fastening of the guide ring 22 and of the platform 21 is dispensed with.
As seen in the flow direction of the working fluid 20 , the platforms 21 form the front ring 25 and the guide ring 22 forms the rear ring 26 . The front ring 25 has integrally formed on it, radially on the inside, a first collar 27 which extends in the direction of the following rear ring 26 along the conical run of the hot-gas duct 13 . The rear ring 26 has integrally formed on it, radially on the outside, a further collar 28 which overlaps the first collar 27 , as seen radially from the inside outward, so that the annular gap 23 is formed in cross section as an overlap gap. An overlap gap, in which the radially outer collar 28 is arranged on the front ring 25 and the inner collar 27 is arranged on the rear ring 26 , would, of course, also be possible.
Along the annular gap 23 , as seen from the inside outward, the latter first has a gap portion which runs in the radial direction and which is deflected in a bend 38 by the outer collar 28 , so that said gap portion has adjoining it in the axial direction a gap portion 29 which extends counter to the flow direction of the working fluid 20 . A second bend then occurs, which deflects the annular gap 23 into the radial direction again.
An annular bearing surface 32 is arranged on that side of the first collar 27 which faces away from the working fluid 20 . The annular supporting surface 33 is located, opposite the annular bearing surface 32 , on the outer collar 28 .
A groove, preferably a circumferential groove 31 , is provided in that end face 30 of the rear ring 26 which faces the front ring 25 .
The first end 34 of the spring element 24 is crimped and inserted into the circumferential groove 31 . In this case, the circumferential groove 31 may be somewhat smaller in its width than double the material thickness of the spring element 24 , in order to achieve an effectively bearing and reliable connection to the rear ring 26 . The spring element 24 may likewise be soldered or welded in the circumferential groove 31 to the rear ring 26 .
The first end 34 of the spring element 24 has adjoining it, in cross section, a spring region which runs in a slightly convex arc and which is supported on the annular supporting surface 33 . A prestress in the spring element 34 is thereby generated which is directed in the direction of the annular bearing surface 32 .
The convex arc, that is to say the spring region of the spring element 24 , has adjoining it a free second end 35 formed by a concave arc 39 . In order to achieve a good displaceability of the second end 35 on the annular bearing surface 32 , the concave arc 39 of the spring element 24 bears, air-tight, against the annular bearing surface 32 along a contact line 40 directed in the circumferential direction.
A rear space 36 separated from the hot-gas duct 13 by the rings 25 , 26 is separated, air-tight, from the hot-gas duct 13 by means of the spring element 24 which bears against the two rings 25 , 26 and is likewise designed as a ring consisting of segments.
In order to cool the rings 25 , 26 or ring segments acted upon by the hot working fluid 20 , in the rear space 36 a cooling fluid flows, the pressure of which is higher than that of the working fluid 20 . The prestress of the spring element 24 is assisted by the force generated by the pressure drop, so that the spring element 24 is pressed even more firmly against the annular bearing surface 32 . A low cooling fluid outflow as a result of positional deviations, not to be ruled out, between individual segments of a ring or as a result of a surface roughness of the annular bearing surface 32 serves for cooling the spring element 24 .
The spring element 24 may in this case be produced from a heat-resistant alloy, for example from an alloy bearing the tradename of Nimonic 90 .
FIG. 3 shows the two rings 25 , 26 in a position displaced in relation to one another after thermal expansion has taken place. In respect of FIG. 1 , the length of the gap portion 29 is shortened, as seen in the flow direction of the working fluid 20 , but the distance between the two collars 27 , 28 or the distance of the annular bearing surface 32 from the annular supporting surface 33 has increased, as compared with FIG. 1 . As regards the rotor 3 , the two rings 25 , 26 forming the annular gap 23 are displaced in relation to one another both in the radial direction and in the axial direction.
Alternatively to FIG. 3 , FIG. 4 shows a spring element 24 clamped in the manner of a joint as a result of the calking of the circumferential groove 31 , so that there is a slight movability of the spring element 24 in the manner of a hinge.
By virtue of the spring prestress, the free end 35 of the spring element 24 remains in contact with the annular bearing surface 32 in spite of the high displacement travel and thus seals off the rear space 36 with respect to the hot-gas path 13 . Slight leakage streams of cooling fluid through the annular gap 23 into the hot-gas duct are in this case possible, and, as compared with the prior art, an improvement in the sealing action and a reduction in leakage are furthermore achieved.
Owing to the annular arrangement of the platforms 21 and guide rings 22 and due to the radial mounting required for these components, the platforms 21 described in the description and claims, the guide blade rings 15 , the rings 22 , 25 , 26 and also the spring elements 24 are in each case to be understood as meaning only segments of the respective ring.
Furthermore, the sealing means proposed may be used both between adjacent platforms of an individual blade ring and in other regions of the gas turbine, for example in the combustion chamber, when an overlap gap is formed between the components to be sealed off. | A gas turbine, with a fixed inner housing, arranged concentric to the rotor, with a through flow of working medium, is disclosed. The housing comprises at least two serial rings with an annular gap left between two directly adjacent rings, whereby an annular sealing means is arranged in at least one peripheral groove for sealing the annual gap. According to the invention, a sealing means is provided which permits a greater movement of both components forming the gap, whereby the annual gap is formed by partly overlapping rings, running against the flow direction of the working fluid in the radial sense and the front most of the two rings, in the sense of the flow direction, comprises a locating annular surface for the sealing means embodied as an annular spring element on which the spring element rests under tension such as to seal the annular gap. | 5 |
CROSS REFERENCE TO RELATED UNITED STATES APPLICATIONS
[0001] This application claims priority from “Multi-image Based Stent Visibility Enhancement”, U.S. Provisional Application No. 61/243,266 of Chen, et al., filed Sep. 17, 2009, the contents of which are herein incorporated by reference in their entirety.
TECHNICAL FIELD
[0002] This disclosure is directed to enhancing the visibility of stents in digital medical mages.
DISCUSSION OF THE RELATED ART
[0003] During a stent placement procedure, a sequence of fluoroscopic X-ray images is usually acquired to check the stent position. Thus, stent visibility in a fluoroscopic image is of great importance in an intervention procedure for accurate stent placement. However, the image's signal to noise ratio is usually very low due to the low-dosage imaging conditions prevalent during the intervention procedures.
[0004] Images are typically modeled as additive signal. For X-Ray images, this can be satisfied by applying a log function to image intensity. The log compressed images are usually formulated as follows:
[0000] I i =T i ( I S )+ C i ,iε[ 1, . . . , K], (1)
[0000] where I i is one of the acquired images, K is the total number of images, I S is the stent image to be recovered, T i represents the motion of the stent on each image, and C i is anything that does not belong to the stent image, which might include unrelated organs or tissue as well as imaging noise. Since the stent is moving during image acquisition, the observed image is a mixture of the deformed stent image (i.e., T i (I S )) and clutter C i . Traditionally, it is usually assumed that the clutter C i only includes imaging noise which is zero-mean and independent between observed images. Based on this simplified assumption, the stent image can be recovered by an align- and average method, i.e., aligning all the images and averaging all aligned frames:
[0000]
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[0000] However, the previous assumption is over-simplified because the images also include other patient organs and vessels which do not belong to the stent image. These structures are usually not independent between images. The organs are deformed and overlaid onto the whole series of images. A more accurate imaging model hence should explicitly model the clutter layer and its motion, which can be formulated as follows:
[0000] I i =T i S ( I S )+ T i C ( I C )+ N i ,iε[ 1, . . . , K] (2)
[0000] where I C is the clutter layer, T i C ( ) is the motion of the clutter layer and N i is an independent zero-mean imaging noise.
[0005] This new model requires a different method to solve other than the usual align-and-average. Traditional averaging can only provide a result that s a mixture of the true stent image and a motion blurred clutter layer.
[0006] By explicitly modeling the clutter layer and its motion, one can separate the motion blurred clutter layer and the stent image, hence significantly enhancing the visibility of the stent.
SUMMARY OF THE INVENTION
[0007] Exemplary embodiments of the invention as described herein generally include methods and systems for enhancing stent visibility based on multiple input images during an invention procedure. The input to an algorithm according to an embodiment of the invention is a series of images acquired of a stent to which a pair of balloon markers are attached. The output is an enhanced stent image based on the acquired series. A stent visibility enhancement according to an embodiment of the invention is performed in a batch processing mode, in that a whole image sequence is captured first, then the enhancement is applied based on the whole sequence to generate one enhanced image of the stent. A method of enhancing stent visibility in a digitized image according to an embodiment of the invention, including the input and output, is as follows, as shown in FIG. 1 : (step 11 ) detect the location of the balloon marker pair; (step 12 ) estimate stent motion based on the detected balloon markers; (step 13 ) pre-process all acquired image frames so that the images satisfy the algorithm requirements, including intensity remapping, so that the images satisfy the additive model, and lighting compensation; (step 14 ) based on the multiple images, decompose the image into a stent layer and a clutter layer; and (step 15 ) align the stent and vessel images for better inspection of the stent placement. Details of these steps are provided below.
[0008] According to an aspect of the invention, there is provided a method for enhancing stent visibility in digital medical images, including providing a time series of 2-dimensional (2D) images of a stent in a vessel, estimating motion of the stent in a subset of images of the time series of images, estimating motion of clutter in the subset of images, where clutter comprises anatomical structures other than the stent, estimating a clutter layer in the subset of images from the estimated clutter motion, estimating a stent layer in the subset of images from the clutter layer and the estimated clutter motion, and minimizing a functional of the estimated stent motion, the estimated stent layer, the estimated clutter motion, and the estimated clutter layer to calculate a refined stent layer image, where the refined stent layer image has enhanced visibility of the stent.
[0009] According to a further aspect of the invention, the method includes aligning the refined stent layer image with an image of the vessel.
[0010] According to a further aspect of the invention, the stent has a pair of balloon markers attached thereto, and further comprising attempting to detect a 2D location of the balloon markers in each of the images, where the subset of images has as members those images in which the balloon marker locations are detectable.
[0011] According to a further aspect of the invention, estimating stent motion comprises selecting a first image of the subset of images as a reference image, and for each remaining image in the subset of images, using the 2D balloon marker locations to calculate a 2D translation of a current image with respect to the reference image, a rotation angle from an angle difference of the 2D balloon marker locations in the current image with respect to the reference image, and an axial scaling of the stent in the current image with respect to the reference image, and calculating the stent motion from the translation, rotation, and scaling.
[0012] According to a further aspect of the invention, the method includes pre-processing each image in the subset of images to make the image intensities additive, and to compensate for changes in lighting in the ages of the subset of images.
[0013] According to a further aspect of the invention, clutter motion is initialized to zero.
[0014] According to a further aspect of the invention, wherein minimizing the functional of the estimated stent motion, the estimated stent layer, the estimated clutter motion, and the estimated clutter layer includes repeating the steps of estimating clutter motion, estimating a clutter layer, estimating a stent layer, and minimizing a functional until the refined stent layer image converges.
[0015] According to a further aspect of the invention, clutter motion is estimated by subtracting the refined stent layer image from each image in the subset of images to obtain an estimated clutter layer corresponding to each image in the subset of images, and estimating clutter motion from differences in the clutter images.
[0016] According to a further aspect of the invention, estimating a clutter layer comprises calculating
[0000]
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[0000] where Î C represents the estimated clutter layer, K is the number of ages in the subset of images, I i is a member of the subset of images, T i C represents the clutter motion, Î S represents the stent layer estimated in a previous iteration, and T i S represents the stent layer motion.
[0017] According to a further aspect of the invention, estimating a stent layer comprises calculating
[0000]
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[0000] where Î S represents the stent layer, Î C represents the estimated clutter layer.
[0018] According to a further aspect of the invention, minimizing a functional to calculate a refined stent layer image comprises calculating
[0000]
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S
=
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[0000] where T i S represents the stent motion.
[0019] According to a another aspect of the invention, there is provided a method for enhancing stent visibility in digital medical images, including providing a time series of 2-dimensional (2D) images of a stent in a vessel, where the stent has a pair of balloon markers attached thereto, attempting to detect a 2D location of the balloon markers in each of the images, and selecting a subset of images having as members those images in which the balloon marker locations are detectable, estimating motion of the stent from the 2D balloon marker locations in each image of the subset of images, pre-processing each image in the subset of images to make the image intensities additive, and to compensate for changes in lighting in the images of the subset of images, separating an image layer containing the stent from an image layer containing clutter in each image of the subset of images, where clutter comprises anatomical structures other than the stent, and aligning the stent image layer with an image of the vessel, where the aligned images have enhanced visibility of the stent placement in the vessel.
[0020] According to a further aspect of the invention, separating an image layer containing the stent from an image layer containing clutter in each image includes estimating clutter motion in the subset of images, estimating a clutter layer in the subset of images from the estimated clutter motion, estimating a stent layer in the subset of images from the clutter layer and the estimated clutter motion, and repeating the steps of estimating clutter motion, estimating a clutter layer, and estimating a stent layer until the refined stent layer image converges, where the refined stent layer image has enhanced visibility of the stent.
[0021] According to a further aspect of the invention, repeating the steps of estimating clutter motion, estimating a clutter layer, and estimating a stent layer minimizes a functional
[0000]
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[0000] where I C represents the estimated clutter layer, K is the number of images in the subset of images, I i is a member of the subset of images, T i C represents the clutter motion, I S represents the stent layer estimated in a previous iteration, and T i S represents the stent layer motion, where Î S is a stent layer I S that minimizes the functional.
[0022] According to a another aspect of the invention, there is provided a program storage device readable by a computer, tangibly embodying a program of instructions executable by the computer to perform the method steps for enhancing stent visibility in digital medical images.
BRIEF DESCRIPTION OF THE DRAWINGS
[0023] FIG. 1 is a flowchart of a method for enhancing the visibility of stents in digital medical images, according to an embodiment of the invention.
[0024] FIG. 2 is a flowchart of a method for layer separation, according to an embodiment of the invention.
[0025] FIGS. 3( a )-( b ) and 4 ( a )-( b ) depict results of stent visibility enhancement experiments comparing an align-and-average method to a method according to an embodiment of the invention.
[0026] FIG. 5 is a block diagram of an exemplary computer system for implementing a method for enhancing the visibility of stents in digital medical images, according to an embodiment of the invention.
DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS
[0027] Exemplary embodiments of the invention as described herein generally include systems and methods for to enhancing the visibility of stents in digital medical images. Accordingly, while the invention is susceptible to various modifications and alternative forms, specific embodiments thereof are shown by way of example in the drawings and will herein be described in detail. It should be understood, however, that there is no intent to limit the invention to the particular forms disclosed, but on the contrary, the invention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention.
[0028] As used herein, the term “image” refers to multi-dimensional data composed of discrete image elements (e.g., pixels for 2-D images and voxels for 3-D images). The image may be, for example, a medical image of a subject collected by computer tomography, magnetic resonance imaging, ultrasound, or any other medical imaging system known to one of skill in the art. The image may also be provided from non-medical contexts, such as, for example, remote sensing systems, electron microscopy, etc.
[0029] Although an image can be thought of as a function from R 3 to R or R 7 , the methods of the inventions are not limited to such images, and can be applied to images of any dimension, e.g., a 2-D picture or a 3-D volume. For a 2- or 3-dimensional image, the domain of the image is typically a 2- or 3-dimensional rectangular array, wherein each pixel or voxel can be addressed with reference to a set of 2 or 3 mutually orthogonal axes. The terms “digital” and “digitized” as used herein will refer to images or volumes, as appropriate, in a digital or digitized format acquired via a digital acquisition system or via conversion from an analog image.
Balloon Marker Detection
[0030] Balloon markers usually have a circular shape and a range of possible sizes. Hence, a balloon marker can usually be detected by a template matching type of algorithm. But simple template matching usually produces significant false detections as well. It becomes necessary to explicitly verify that a high matching score is really caused by a circular shape instead of some other high contrast structures such as guide-wire tips or other intervention tools. Other information, such as a pair of markers that maintain a similar distance or angle can be also helpful. Since balloon marker detection algorithms are known in the art, and an algorithm according to an embodiment of the invention does not depend on any particular implementation of a detection algorithm, only the result, details of the detection part will not be further discussed herein.
[0031] A detection algorithm is applied to every image frame of the series of acquired images to detect a pair of balloon markers. In the case that the markers cannot be reliably detected or the markers have moved out of the image, the detection result for that frame is set to zero.
Stent Motion Estimation
[0032] For those frames in which the balloon markers can be detected, one can estimate the motion of the stent, i.e., T i S ( ). To estimate stent motion, a reference image is selected, usually the first image in a sequence of images for which the balloon markers can be detected. Then, according to an embodiment of the invention, the stent motion is estimated for every other image frame (for which the balloon markers can be detected) with respect to the reference image. Since one has the location of a pair of markers in a 2D space, the motion can be estimated with up to 4 degrees of freedom (DOF), including a 2D translation (2 DOF), rotation (1 DOF) and scaling (1 DOF), and can be represented by a 3×3 aflame transformation matrix that is a product of the translation matrix, rotation matrix, and scaling matrix. It is worth noting that the scaling should not be the traditional isotropic scaling. Instead, it should be a scaling along the long axis of the stent due to the fact that the stent can have out-of-plan rotation or stretching motion. A motion model according to an embodiment of the invention can be calculated as follows.
[0033] 2D Translation: translation can be calculated from the displacement between the center of the detected marker pairs in the reference frame and a current frame.
[0034] Rotation: rotation angle can be calculated from the angle difference between the detected marker pairs in the reference frame and the current frame.
[0035] Axial Scaling: Because the stent is actually moving in 3D space, there are several factors that can change the distance between the markers, such as zooming, out-of-plane rotation, and a significant change of depth. According to an embodiment of the invention, it may be assumed that out of plane rotation or stretching are the primary causes for the marker distance to change. Base on this assumption, the scaling should only be applied along the length of the stent while the diameter of the stent should not change.
Pre-Processing
[0036] A pre-processing step according to an embodiment of the invention includes two parts. First, a remapping curve is applied to input image intensity to make the image more additive. Second, a lighting compensation procedure is performed to compensate for lighting changes during the acquisition of the series (mostly seen in first several frames in the series).
[0037] Since most image processing techniques assume the image to be additive signal, it is necessary to remap the image intensity to assure additive property. If input images are raw intensity images, a log function remapping can achieve this: I i ′=log(I i ). If input images have already been through some remapping, the remapping function should be readjusted accordingly.
[0038] To compensate for changes in lighting, a large neighborhood low-pass filter may be applied to each frame after remapping to estimate the non-stationary lighting condition of that frame and to subtract it: I i ″I i ′=−F(I i ′), where F represents the low-pass filter. This way, the brightness of each frame in the series can be comparable. An exemplary, non-limiting low pass filter is based on a neighborhood that is large with respect to the size of an image, for example, a 125×125 pixel neighborhood in a 512×512 pixel image.
Layer Separation
[0039] According to the model of EQ. (2), one needs to estimate the stent layer I S , the clutter layer I C and their motion T i S ( ) and T i C ( ) on every observed images jointly. According to an embodiment of the invention, this estimation can be formulated as an energy optimization problem as follows:
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[0040] According to an embodiment of the invention, assuming one can obtain an estimation of the stent motion T i S ( ), clutter motion T i C ( ) and the appearance of the stent and clutter layers, i.e., I S and I C , one should be able to predict how each acquired frame looks except for the imaging noise. Assuming the imaging noise is zero-mean independent Gaussian distributed noise, one can derive the optimization objective function as shown in EQ. (3).
[0041] This objective function can be solved by iterative optimization steps. As one approaches the true solution, one can predict each frame more accurately and the error term is minimized. FIG. 2 is a flowchart of a method according to an embodiment of the invention for separating the stent and clutter layers. Referring now to the figure, a method begins at step 20 by providing a sequence of images. As described above, the enhancement is estimated based on the whole image sequence to generate one enhanced image of the stent. Next, at step 21 the stent motion is estimated. However, since the stent motion T i S ( ) can be estimated based on balloon markers as described above, there is no need to re-estimate the stent motion during the optimization, and the previously estimated stent motion results may be used instead.
[0042] At step 22 , the clutter layer motion is estimated. However, because the stent usually has a very weak contrast, its presence does not dramatically affect the clutter layer motion estimation. Hence, one can initially estimate the clutter layer motion T i C ( ) based on the input series of images directly. For subsequent steps in the iteration, the clutter layer motion may be estimated by subtracting the stent structure from the input image. Observing that (1) I i =I C,i +I S,i , i.e. the observed image=clutter layer+stent layer, (2) I C,i =T i C (I C ), i.e., the clutter layer at time i is represented as clutter layer deformed by T i C , and (3) I S,i =T i S (I S ), i.e., the stent layer at time i is represented as stent layer I S deformed by its motion T i S , one can estimate T i C at subsequent iterations by combining the I S estimation from the stent layer estimation with the estimated stent layer motion to remove I S,i , from I, leaving only the I C,i term. From this, one can obtain a more accurate estimation of the clutter layer motion in successive iterations.
[0043] At step 23 , the clutter layer is estimated. Once the clutter layer motion estimated, the clutter layer can be estimated as follows:
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[0044] Since the stent layer is unknown, one can use the estimated stent image in a previous iteration to be subtracted from each observed image. In the first iteration, one can assume the stent layer to be all zero.
[0045] At step 24 , the stent layer is estimated, based on the estimation of the clutter layer and its motion:
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[0046] In step 25 , it is determined if it is necessary to further refine the estimation of T i C ( ), Î C and Î S . If current iteration does not significantly change these estimations, or the update is not further reducing the objective function of EQ. (3), or the number of iteration has reached a preset threshold, the iterations can be stopped and the Î S can be presented as the final result. By iterating steps 22 , 23 , 24 , one gradually optimizes the objective function of EQ. (3).
[0047] With explicit modeling of the clutter layer, one can separate the clutter layer from the stent image Î S and hence obtain a cleaner stent image than traditional averaging method.
Align Stent/Vessel Images
[0048] After the enhanced stent image has been obtained, it can be aligned at step 26 to a contrast image which highlights the vessel tree. Displaying these two aligned images (stent image and vessel image) together allows a better visualization of the stent placement.
[0049] The alignment is performed based on the balloon markers on both stent image and vessel image as well. The motion model is the same as previously described above. With the two aligned images, there are different options to visualize the two images. One choice would be to invert the intensity of one image and perform a fade in/out animation between the two aligned images.
Experimental Results
[0050] An algorithm according to an embodiment of the invention was applied to more than 30 clinical sequences and promising results were obtained. Comparisons were performed against align-and-average methods to see the changes with respect to a method according to an embodiment of the invention.
[0051] The first sequence has rather good signal to noise ratio, with about 50 frames in the sequence. FIG. 3( a ) shows that a traditional averaging method can only blur the clutter layer, instead of removing it. The clutter structures disturb the stent visibility. Thanks to the good signal to noise ratio, the stent can still be seen in averaging result. On the other hand, a layer separation method according to an embodiment of the invention can successfully remove the unrelated clutter layer and improve the visibility of the stent, as shown in FIG. 3( b ).
[0052] In the second sequence, the stent has very low signal to noise ratio. FIG. 4( a ) shows that the stent is barely visible after averaging over 30 frames in the sequence. As shown in FIG. 4( b ), a layer separation method according to an embodiment of the invention can successfully remove the unrelated clutter layer and enhance the visibility dramatically based on the same number of frames.
[0053] These experiments show that an algorithm according to an embodiment of the invention is robust to very low signal-to-noise ratio and can work in widely different imaging settings. A layer separation algorithm according to an embodiment of the invention can successfully remove unrelated clutter and dramatically enhance the stent visibility.
System Implementation
[0054] It is to be understood that embodiments of the present invention can be implemented in various forms of hardware, software, firmware, special purpose processes, or a combination thereof. In one embodiment, the present invention can be implemented in software as an application program tangible embodied on a computer readable program storage device. The application program can be uploaded to, and executed by, a machine comprising any suitable architecture.
[0055] FIG. 5 is a block diagram of an exemplary computer system for implementing a method for multi-image based stent visibility enhancement according to an embodiment of the invention. Referring now to FIG. 5 , a computer system 51 for implementing the present invention can comprise, inter cilia, a central processing unit (CPU) 52 , a memory 53 and an input/output (I/O) interface 54 . The computer system 51 is generally coupled through the I/O interface 54 to a display 55 and various input devices 56 such as a mouse and a keyboard. The support circuits can include circuits such as cache, power supplies, clock circuits, and a communication bus. The memory 53 can include random access memory (RAM), read only memory (ROM), disk drive, tape drive, etc., or a combinations thereof. The present invention can be implemented as a routine 57 that is stored in memory 53 and executed by the CPU 52 to process the signal from the signal source 58 . As such, the computer system 51 is a general purpose computer system that becomes a specific purpose computer system when executing the routine 57 of the present invention.
[0056] The computer system 51 also includes an operating system and micro instruction code. The various processes and functions described herein can either be part of the micro instruction code or part of the application program (or combination thereof) which is executed via the operating system. In addition, various other peripheral devices can be connected to the computer platform such as an additional data storage device and a printing device.
[0057] It is to be further understood that, because some of the constituent system components and method steps depicted in the accompanying figures can be implemented in software, the actual connections between the systems components (or the process steps) may differ depending upon the manner in which the present invention is programmed. Given the teachings of the present invention provided herein, one of ordinary skill in the related art will be able to contemplate these and similar implementations or configurations of the present invention.
[0058] While the present invention has been described in detail with reference to exemplary embodiments, those skilled in the art will appreciate that various modifications and substitutions can be made thereto without departing from the spirit and scope of the invention as set forth in the appended claims. | A method for enhancing stent visibility in digital medical images includes providing a time series of 2-dimensional (2D) images of a stent in a vessel, estimating motion of the stent in a subset of images of the time series of images, estimating motion of clutter in the subset of images, where clutter comprises anatomical structures other than the stent, estimating a clutter layer in the subset of images from the estimated clutter motion, estimating a stent layer in the subset of images from the clutter layer and the estimated clutter motion, and minimizing a functional of the estimated stent motion, the estimated stent layer, the estimated clutter motion, and the estimated clutter layer to in calculate a refined stent layer image, where the refined stent layer image has enhanced visibility of the stent. | 6 |
BACKGROUND OF THE DISCLOSURE
The subject invention relates generally to security devices and more particularly to a security device for securing products or product packing devices such as pallets and crates used, for example, in retail distribution.
According to prior procedures, reusable packing devices such as pallets, crates, trays, boxes etc., have been used in the shipping of goods. Such devices are often left unattended in open areas where they are exposed to theft or damage. Building materials such as lumber are often similarly left exposed in construction areas and are favorite targets of theft and vandalism.
SUMMARY OF THE INVENTION
It is therefore an object of the invention to provide a security device for products and product packing devices.
It is another object of the invention to provide a security device for such packing devices and products which is conveniently locatable near the working area where such products and devices are frequently stored or used.
It is yet another object of the invention to provide such a security device which is safe and easy to operate.
Accordingly, the invention provides a secured, free standing clamping apparatus particularly designed to retain pallets and other types of packing devices or products. The apparatus employs a clamping pad moveably mounted on a vertical member. The pad is adjustable to accomodate stacks of various heights of products or packing devices and is lockable in a clamping mode to secure the products or packing devices in position. According to a feature of the invention, the pad may be interchangeable in order to adapt the apparatus of the invention to various types of products or packing devices. The invention further has the advantage of enabling the secure use of previously unused space outside of a retail establishment or warehouse.
BRIEF DESCRIPTION OF THE DRAWINGS
The preferred embodiment of the invention will now be disclosed in conjunction with the drawings of which:
FIG. 1 is a perspective of the preferred embodiment of the invention.
FIG. 2 is a side plan view of the preferred embodiment of the invention.
FIG. 3 is a sectional view taken at 3--3 of FIG. 2.
FIG. 4 is a sectional view illustrating the crank rail of the preferred embodiment of the invention.
FIG. 5 is a sectional view taken at 5--5 of FIG. 2.
FIG. 6 is a sectional view of the top of the vertical column of the preferred embodiment.
FIGS. 7 through 12 illustrate various alternative embodiments.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
As illustrated in FIG. 1, the preferred embodiment includes a vertical frame member 11 attached to a center base member 25 and braced by front and rear crank rails 15, 17. The front crank rail 15 rigidly attaches to a front upright member 19, which is rigidly attached to a center base 25. The center base 25 and rear crank rail 17 are each attached to a rear frame 13. The rear frame 13 includes two frame sections 16, 18 each welded to a respective side of upper and lower tubular adjustment brackets 29, 31. Alternatively, the horizontal rear frame members may be of single piece construction with adjustment brackets welded or otherwise attached on the under surface thereof. Each rear frame section 16, 18 is braced by respective rear uprights 21, 23. The frame structure is generally of square metal tubular construction.
The rear crank rail 17 and center base member 25 are attached to the rear frame 13 by the upper and lower adjustment brackets 29, 31. These brackets 29, 31 and the accompanying pins 32 permit the center base member 25 and rear crank rail 17 to be selectively positioned. With the pins 32 removed, the position of the rear crank rail 17 and center base 25 may be slidably adjusted in a direction perpendicular to the plane of the rear frame 13. Such adjustment enables the preferred embodiment to better accomodate various sizes of pallets or other containers.
In FIG. 1, a sleeve 45 is slidably mounted on the vertical column 11. An arm swivel 43 is pivotally mounted by a pin 51 to the sleeve 45. First and second receivers 39 41 are welded to the swivel arm 43 at an angle, for example, of thirty degrees in the embodiment shown. First and second square tubular arms 35, 37 are inserted into the respective receivers 39, 41 and bolted into position. First and second pads 31, 33 are pivotally mounted by pivots 49, 47 at the end of each arm 35, 37, opposite the receivers 39, 41. These pads 31, 33 present a tubular generally "H" shaped construction, depending from perpendicular supports 40, 42. The arms 35, 37 and pads 31, 33 are removable, providing interchangeability with other arms and pads designed to accomodate other packing devices. The sleeve 45, swivel 43, arms 35, 37 and pads 31, 33 comprise a clamping mechanism slidably mounted on the vertical column 11.
A base plate 27 is further bolted to the center base 25. The base plate 27 facilitates assertion of upward as well as downward clamping forces and precludes any tendency of the preferred embodiment to rise off the ground in response to the assertion of downward force by the clamping pads 31, 33. The preferred embodiment is preferably fastened to the ground by suitable L brackets 97 attached to the front upright 19 and rear frame 13.
In operation, the pivot points provided by pivots 47, 49, 51 provide an improved clamping function. In particular the flexibility of movement provided enables accomodation of loads of varying heighth or surface irregularity.
The sleeve 45 and accompanying clamping pads 31, 33 are driven up and down the vertical column 11 by a chain and crank mechanism. To facilitate this operation, the sleeve 45 is attached to a chain 53, which rides on sprockets, e.g. 85, within the vertical column 11 (FIG. 5). The chain exits the vertical column 11 via a slot 88 therein. A chain guard 55 is attached between a bracket 81 and a gear box 59 and seals off access to the chain 53. In an alternate embodiment, a cable may be used in place of the chain 53.
Driving power is supplied to the gear box 59 by a crank rod 61 (FIG. 4) rotatably mounted on the front crank rail 15. The crank rod 61 is driven by a removable crank handle 73 mounted by means of a pin 62 inserted in a suitable pin hole 63.
The preferred embodiment further incorporates a locking mechanism illustrated in detail in FIGS. 3 and 4. As shown, a locking gear 65 is fixedly mounted to the crank rod 61. The locking gear 65 forms part of the ratchet locking mechanism together with a locking lever comprising elements 69, 71 and a spring 75. The locking lever elements 69, 71 are rigidly attached to one another and pivotally mounted by a pivot 77. The spring 75 maintains the locking lever 69, 71 engaged with the locking gear 65. This engagement precludes accidental slipping of the clamping mechanism on column 11, thereby providing a safety feature. In addition, the locking lever element 69 is provided with a circular aperture 79. A complimentary aperture 78 (FIG. 1) is formed in the crank plate 67. The complimentary apertures 79, 78 facilitate the insertion of a padlock or other locking mechanism to lock the clamping mechanism in position. A concentric shaft cover may also be welded to the crank plate 67 to surround and protect the exposed end of the crank rod 61 which carries pin 62. Such a shaft cover should be of sufficient diameter to enable insertion of crank handle 73.
The gear box 59 is a typical reduction gear box including a second sprocket for the chain 53 and providing for the assertion of approximately 200-5,000 pounds of force (100-2,500 pounds/arm) by the clamping pads 31, 33.
FIG. 5 illustrates an adjustment mechanism provided at the top of the vertical column 11. A sleeve 83 is slidably mounted with respect to the vertical column 11. The sleeve 83 and vertical column 11 contain complimenting slots providing an aperture 87 through which the sprocket shaft 86 is inserted. The sprocket shaft 86 is bolted to the sleeve 83 such that it may be selectively positioned within the aperture 87. A plate 93 is fixed to the top of the vertical column 11 and a plate 91 parallel to the plate 93 is fixed in the adjustment sleeve 83. A tension adjuster bolt 89 is threadably inserted into a nut 95, which is welded or otherwise attached to the sleeve plate 91. A tension adjustment may thus be provided by turning of the bolt 89.
The preferred embodiment is particularly adapted to the storing of pallets 34. The frame structure provided squares off the pallet load and the pivotal mounting of the clamping pads 31, 33 accomodates variations in the size of respective stacks of pallets 34. With a vertical column heighth of ten feet, two pallet stacks of approximately 15 pallets may be safely retained in position. While the preferred embodiment employs a removable hand crank mechanism, it is additionally possible to use a gear motor mounted to the top of a vertical column 11 to provide a motorized drive.
Variations in the design of the clamping structure used in the preferred embodiment are possible as illustrated in FIGS. 7 through 12. FIG. 7 illustrates a frame member 90 substitutable for frame member 13 and particularly adapted for storing milk crates. FIGS. 8 and 9 show top and side views of a clamping pad 92 forming a substantially rectangular cap of angle iron construction suitable for retaining milk crates. FIGS. 10 and 11 illustrate a base structure 91 usable with the frame 90 and pad 92 of FIGS. 7-9. FIG. 12 illustrates a U-shaped base member 94 usable, for example, in a pallet holding embodiment. In such an embodiment, a vertical column 11 and an associated clamping mechanism as shown in FIG. 2 may be disposed above the base 94. Thus, specially designed clamping pads may cooperate with specially designed base and frame members to clamp various types of containers. It is further possible to simply use one arm and clamping pad rather than a dual arm embodiment as disclosed.
As is apparent, various modifications and adaptations of the preferred embodiment will be apparent to those skilled in the art without departing from the scope and spirit of the invention. Therefore it is to be understood that, within the scope of the appended claims, the invention may be practiced other than as specifically described herein. | A security device for storing and retaining of products or product packing devices such as pallets, crates and the like having a clamping mechanism slidably mounted on and drivable with respect to a vertical column, the clamping mechanism including one or more pivotally mounted arms carrying one or more clamping pads adapted to clamp a stack of products or product packing devices between a pad and base member of the device. | 4 |
[0001] This application is a continuation of Application No. PCT/US03/12449 filed on Apr. 14, 2003 which is a continuation of and claims the benefit of U.S. Provisional Application No. 60/375,800 filed Apr. 26, 2002 and 60/377,516 filed May 3, 2002.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to an improved fuse cutout and, more particularly, to an improved fuse cutout that has increased dropout characteristics and operating performance. The improved fuse cutout of the present invention is of the type shown in S&C Electric Co. Descriptive Bulletin 351 - 30 , dated Dec. 7, 1998, entitled “S&C Type XS Fuse Cutouts” and in U.S. Pat. Nos. 2,553,098; 2,745,923 and 4,414,527. This type of fuse cutout may be used with a fuse link of the type sold by S&C Electric Co. as the Positrol® Fuse Link and as generally shown in U.S. Pat. Nos. 4,317,099.
[0004] 2. Discussion of the Prior Art
[0005] Fuse cutouts and fuse links utilized therein are well known. A typical fuse cutout includes a hollow insulative fuse tube having conductive ferrules mounted to the opposite ends thereof. One ferrule (often called the “exhaust” ferrule) is located at an exhaust end of the fuse tube and usually includes a trunnion which interfits with a trunnion pocket or hinge of a first contact assembly carried by one end of an insulator. The other ferrule is normally held and latched by a second contact assembly carried by the other end of the insulator so that the fuse tube is normally parallel to, but spaced from, the insulator. The insulator is mountable to the cross-arm of a utility pole or a similar structure. The fuse link is located within the fuse tube with its ends respectively electrically continuous with the ferrules. One point of an electrical circuit is connected to the first contact assembly, while another point of the circuit is connected to the second contact assembly. Often, the insulator and the fuse tube are oriented generally perpendicular to the ground so that the exhaust ferrule and the first contact assembly are located below the other ferrule and the second contact assembly. The fuse tube may include a high burst strength outer portion—for example, a fiber-glass-epoxy composite having an arc-extinguishing material within the inner portions thereof. Normal currents flowing through the electrical circuit flow without affecting the fuse link. Should a fault current or other over-current, to which the fuse link is designed to respond, occur in the circuit, the fuse link operates as described in more detail hereinafter.
[0006] Operation of the fuse link permits the upper ferrule to disengage itself from the upper contact assembly, whereupon the fuse tube rotates downwardly due to coaction of the trunnion and the hinge. If the fuse link operates properly, current in the circuit is interrupted and the rotation of the fuse tube gives a visual indication that the cutout has operated to protect the circuit, e.g. dropout operation to a so-called dropout position. Typical fuse links include a first terminal and a second terminal, between which there is normally connected a fusible element made of pure silver, silver-tin, or the like. Also connected between the terminals may be a strain wire, for a purpose described below. The second terminal is electrically continuous with, and is usually mechanically connected to, a button assembly, which is engagable by a portion of the upper ferrule on the fuse tube. The first terminal is connected to a flexible, stranded length of cable. Surrounding at least a portion of the second terminal, the fusible element, the strain wire (if used), the first terminal, and some portion of the flexible stranded cable is a sheath. The sheath is typically made of a so-called ablative arc-extinguishing material which, when exposed to the heat of a high-voltage arc, ablate to rapidly evolve large quantities of deionizing turbulent and cooling gases. Typically, the sheath is much shorter than the fuse tube and terminates short of the exhaust end of the fuse tube.
[0007] The free end of the stranded cable exits the fuse tube from the exhaust end thereof and has tension or pulling force maintained thereon by a spring-loaded flipper on the trunnion. The tension or pulling force exerted on the cable by the flipper attempts to pull the cable and the first terminal out of the sheath and out of the fuse tube. The force of the flipper is normally restrained by the strain wire, typical fusible elements not having sufficient mechanical strength to resist this tension or pulling force.
[0008] In the operation of typical cutouts, a fault current or other over-current results, first, in the melting or vaporization of the fusible element, followed by the melting or vaporization of the strain wire. Following such melting or vaporization, a high-voltage arc is established between the first and second terminals within the sheath and the flipper is now free to pull the cable and the first terminal out of the sheath and, ultimately, out of the fuse tube. As the arc forms, the arc-extinguishing materials of the sheath begin to ablate and high quantities of de-ionizing, turbulent and cooling gases are evolved. The movement of the first terminal under the action of the flipper, and the subsequent rapid movement thereof due to the evolved gases acting thereon as on a piston, results in elongation of the arc. The presence of the de-ionizing, turbulent and cooling gas, plus arc elongation, may, depending on the level of the fault current or other over-current, ultimately result in extinction of the arc and interruption of the current at a subsequent current zero. The loss of the tension on the stranded cable permits the trunnion to experience some initial movement relative to the exhaust ferrule which permits the upper ferrule to disengage itself from the upper contact assembly. This initiates a downward rotation of the fuse tube and its upper ferrule to a so-called “dropout” or “dropdown” position.
[0009] As noted above, arc elongation within the sheath and the action of the evolved gases may extinguish the arc. At very high fault current or over-current levels, however, arc elongation and the sheath may not, by themselves, be sufficient to achieve this end. Simply stated, at very high fault current levels, either the sheath may burst (because of the very high pressure of the evolved gas) or insufficient gas may be evolved therefrom to quench the high current level arc. For these reasons, the fuse tube is made of, or is lined with, ablative arc-extinguishing material. In the event the sheath bursts, the arc-extinguishing material of the fuse tube interacts with the arc, with gas evolved as a result thereof achieving arc extinction. If the sheath does not burst, the arc-extinguishing material of the fuse tube between the end of the sheath and the exhaust end of the fuse tube is nevertheless available for evolving gas, in addition to that evolved from the sheath. The joint action of the two quantities of evolved gas, together with arc elongation, extinguish the arc.
[0010] When a fuse tube is properly positioned between the upper and lower contact assemblies of the mounting, the contacts of the fuse tube are firmly engaged within the contact assemblies of the mounting. When the fuse link operates, gases evolved within the fuse tube thrust it against the upper contact assembly of the mounting. Ideally, the contact cap should not disengage the concavity until the fusible elements of the fuse link completely melts to release the tension in the cable and until the initial thrust of the fuse tube subsides. Release of this tension and subsiding of fuse tube thrust permits a limited amount of relative movement between the exhaust ferrule and the trunnion about a toggle joint therebetween. This limited movement permits the contact cap to move out of the concavity and the fuse tube to begin movement toward the dropout position due to rotation of the trunnion in the hinge pocket. If the fuse tube moves too far transversely during its thrusting, the contact cap may disengage the concavity too early. Third, transverse movement of the fuse tube can apply a bending movement thereon. This bending movement can fracture the fuse tube near the exhaust ferrule. Corrosion that builds up on various parts and dimensional changes of the fuse tube or fuse link sheath, e.g. due to environmental factors, can exacerbate the proper dropout action.
[0011] Thus, it is important for achieving proper operation as explained above that dropout operation be readily achieved in spite of any deleterious operating environments or conditions.
SUMMARY OF THE INVENTION
[0012] Accordingly, it is a principal object of the present invention to provide a cutout with improved dropout performance.
[0013] This and other objects of the present invention are achieved by an improved fuse cutout of the type having a fuse tube assembly that moves to a dropout position upon operation in response to a fault current or other overcurrent. These types of fuse cutouts include the pivotal mounting of the fuse tube assembly with respect to a support hinge with the fuse tube assembly being released for pivotal movement to the dropout position when the fuse cutout has operated. The fuse tube assembly includes a collapsible toggle joint that collapses upon operation of the fuse cutout. The improved fuse cutout includes additional dropout assistance that is provided via a resilient member operating between the components of the collapsible toggle joint to apply a force to assist the collapse of the toggle joint.
DESCRIPTION OF THE DRAWING
[0014] FIG. 1 is a perspective view of an improved fuse cutout according to the present invention;
[0015] FIG. 2 is an elevational view of a fuse tube assembly of the cutout of FIG. 1 ;
[0016] FIG. 3 is an enlarged, partial view of the fuse tube assembly of FIG. 2 in an operative position; and
[0017] FIG. 4 is an enlarged elevational view of a dropout assist member of the cutout of FIGS. 1-3 .
DETAILED DESCRIPTION
[0018] Referring first to FIG. 1 , there is shown an improved cutout 12 according to the present invention that includes an insulator 14 and a mounting member 16 extending therefrom. The mounting member 16 permits mounting of the insulator 14 and the fuse cutout 12 to an upright or a crossarm of a utility pole or the like (not shown). Affixed to the upper end of the insulator 14 is an upper contact assembly generally designated 18 . Further, affixed to the lower end of the insulator 14 is a lower contact assembly 20 . The cutout 12 also includes a fuse tube assembly 22 (also shown in FIG. 2 ) that in the normal, circuit-connected or unoperated condition of the cutout 12 may be maintained in the generally vertical position shown in FIG. 1 , e.g. cutouts are typically mounted at a slight angle to the vertical.
[0019] Considering now more specific features of the fuse tube assembly 22 , the fuse tube assembly includes an insulative fuse tube 24 of a well-known type, which may comprise an epoxy-fiber-glass composite outer shell lined with an arc-extinguishing material. Mounted or affixed to the upper end of the fuse tube 24 is an upper ferrule assembly 26 , while at the opposite lower or exhaust end of the fuse tube 24 is a lower or exhaust ferrule assembly 28 . In the position of the fuse tube assembly 22 depicted in FIG. 1 , the lower ferrule assembly 28 is held by the lower contact assembly 20 , while the upper ferrule assembly 26 is held, and latched against movement, by the upper contact assembly 18 .
[0020] The upper contact assembly 18 includes a support bar 30 and a recoil arm and contact hood 32 which runs generally parallel to a portion of the support bar 30 . Near the top of the insulator 14 , the bar 30 and the arm 32 are mounted by a fastener or the like at 36 to a portion of a connector assembly 40 that is affixed to the top of the insulator 14 . The connector assembly 40 facilitates the connection to the upper contact assembly 18 to a cable or conductor of a high-voltage circuit.
[0021] The upper contact assembly 18 also includes a spring contact arm 42 and a backup spring 44 that is positioned between the spring contact arm 42 and the recoil arm and contact hood 32 , e.g. the backup spring 44 is positioned at one end over a convexity 45 extending from the top of the contact arm 42 and at the other end over a convexity (not shown) extending downwardly from the recoil arm and contact hood 32 . The backup spring 44 provides high contact pressure between the contact arm 42 and the top of the fuse tube assembly 24 as will be explained in more detail hereinafter. As is typical in the power industry, the support bar 30 at a downwardly bent portion 35 includes attachment hooks 48 for cooperation with a portable loadbreak tool.
[0022] The upper ferrule assembly 26 of the fuse tube assembly 24 includes a ferrule 50 affixed to the upper end of the fuse tube 24 . The ferrule 50 typically includes a threaded portion (not shown) onto which is threaded a contact cap 52 . The contact cap 52 is configured so as to fit into and be held when the fuse tube assembly 22 is in the position shown in FIG. 1 , e.g., by an indentation or concavity (not shown) formed in the spring contact 42 opposite the convexity 45 . The ferrule 50 typically also includes a pull ring 54 . The pull ring 54 may be engaged by a hook stick or the like to move the upper ferrule assembly 26 away from the upper contact assembly 18 while the lower ferrule assembly 28 rotates in the lower contact assembly 20 , as described hereinafter.
[0023] In view of the nature of high voltage circuits, this opening movement of the fuse tube assembly 22 must be effected while the circuit connected to the cutout 10 is de-energized or else an arc will form between the upper ferrule assembly 26 and the upper contact assembly 18 . The fuse tube assembly 22 may also be opened by initially attaching between the attachment hooks 48 and the pull ring 54 a portable loadbreak tool. Such a portable loadbreak tool permits the fuse tube assembly 22 to be opened with the circuit energized, momentarily having transferred thereto the flow of current in the circuit 10 and interrupting such current internally thereof.
[0024] The lower contact assembly 20 includes a support member 56 attached to a mount 58 by a fastener or the like at 60 . The support member 56 carries a connector 62 , such as a parallel groove connector, to facilitate connection of the lower contact assembly 20 to another cable or conductor of the high-voltage circuit in which the fuse cutout 12 is to be used. The support member 56 provides a hinge function via trunnion pockets 64 . The trunnion pockets are designed to cooperate with and hold outwardly extending portions 66 of a trunnion 68 (also shown in FIG. 3 ) carried by the fuse tube 24 . Specifically, a lower ferrule 72 affixed to the fuse tube 24 pivotally mounts the trunnion 68 at a toggle joint 70 . Thus, the trunnion 68 functions as a toggle member and defines a double pivot mounting for the fuse tube 24 , the first pivot being defined at the toggle joint 70 and the second pivot being defined by the extending portions 66 of the trunnion 68 within the trunnion pockets 64 of the hinge support member 56 .
[0025] As hereinafter described, the trunnion 68 and the ferrule 72 are normally rigidly held in the relative position depicted in FIG. 1 . In this normal relative position of the trunnion 68 and the ferrule 72 , the contact cap 52 is engaged by the spring contact 42 to maintain the fuse tube assembly 22 in the position depicted in FIG. 1 . Also, as described in more detail below, when a fuse link (not shown) within the fuse tube 24 operates, the trunnion 68 and the ferrule 72 are no longer rigidly held, and the ferrule 72 may rotate downwardly relative to the trunnion 68 about the toggle joint 70 . This movement of the ferrule 72 permits the contact cap 52 to disengage the spring contact 42 , following which the entire fuse tube assembly 22 rotates about the lower contact assembly 20 via rotation of the extending portions 66 in the trunnion pockets 64 . Considering additional structural features, rotatably mounted to the trunnion 68 is a flipper 74 . A spring 75 mounted between the trunnion 68 and the flipper 74 biases the flipper 74 away from the lower or exhaust end of the fuse tube 24 . The trunnion 68 includes shoulders 76 or other similar features. The support member 56 also includes features, such as shoulders 78 , normally spaced from the shoulders 76 when the extending portions 66 of the trunnion 68 are seated in their respective trunnion pockets 64 . The normal spacing between the shoulders 76 and 78 is sufficient to permit appropriate movement of the fuse tube 24 with respect to the lower contact assembly 20 during operation as explained hereinafter.
[0026] In use, a fuse link is first installed into the fuse tube assembly 22 . Suffice it here to say that the contact cap 52 is removed and the fuse link is inserted into the interior of the fuse tube 24 from the upper end thereof. A portion of the fuse link abuts a shoulder (not shown) at the top of the ferrule 50 , following which the contact cap 52 is threaded back onto the ferrule 50 . Reference may be made to S&C Electric Co. Instruction Sheet 351-500 and the aforementioned patents for additional information and details. A flexible stranded cable 80 forming a part of the fuse link exits an exhaust opening at 81 in the lower or exhaust end of the fuse tube 24 . The flipper 74 is manually rotated against the action of the spring 75 to position it adjacent the exhaust opening at 81 following which the cable 80 is laid into a channel at 82 in the flipper 74 . Following this, the cable 80 is wrapped around a flanged bolt 84 (shown in FIGS. 2-4 ) that is threaded into the trunnion 68 via a threaded portion 85 . Following tightening of the flanged bolt 84 to hold the cable 80 , the flipper 74 is maintained against the bias of the spring 75 in the position shown in FIG. 1 , whereat there is a constant tension force applied to the cable 80 and the remainder of the fuse link within the fuse tube 24 . It is this connection of the cable 80 to the trunnion 68 by the flanged bolt 84 and the action of the spring 75 on the flipper 74 that normally holds the trunnion casting 68 and the ferrule 72 in the position depicted in FIG. 1 relative to the toggle joint 70 .
[0027] Following operation of a fuse link within the fuse tube 24 , the flipper 74 is able to move the cable 80 downwardly within the fuse tube 24 . The release of the tension force applied to the cable 80 by the flipper 74 permits relative movement of the ferrule 72 and the trunnion 68 about the toggle joint 70 to permit separation of the contact cap 52 from the spring contact 42 . The relative movement of the ferrule 72 and the trunnion 68 occurs after tension in the cable 80 is released and after an initial upward thrust of the fuse tube 24 subsides. As more fully explained in the aforementioned patents, when a fusible element (not shown) of the fuse link within the fuse tube 24 melts, there follows the rapid evolution of arc-extinguishing gas within the fuse tube 24 . This evolved gas exits the exhaust opening at 81 of the fuse tube 24 at a very rapid rate, thrusting the fuse tube 24 upwardly.
[0028] When the fuse link operates, the tension on the cable 80 is released at the same time the fuse tube 24 thrusts up. While the relative movement of the trunnion 68 with respect to the ferrule 72 and about the toggle joint 70 does not immediately occur simultaneously with the rapid gas exhaust, it is able to occur shortly thereafter in response to the release of tension in the cable 80 . This relative movement permits the contact cap 52 to disengage from the contact arm 42 and the fuse tube assembly 22 to rotate to a “dropout” position via rotation of the extensions 66 of the trunnion 68 in the trunnion pockets 64 . All of the above is “timed” so that rotation of the fuse tube assembly 22 is initiated as or after the fuse link has interrupted current in the circuit.
[0029] There is a tendency for frictional resistance caused by corrosion, contamination or sleet such that the trunnion 68 may not be able to pivot about the hinge support member 56 . If that should occur, the fuse tube 24 would remain in place and not dropout, thus not providing the desirable and necessary air gap to prevent leakage over the fuse tube 24 . To this end, an anvil surface 86 is provided on the lower surface of the trunnion 68 that is engaged by the upper edges 88 of the spaced sidewalls 90 of the flipper 74 . Thus, the impact of the flipper 74 as well as the action of the spring 75 act to assist in pivoting the trunnion 68 about the toggle joint 70 . In some circumstances it may be desirable and/or necessary to further improve the dropout performance, especially where 1. the fuse link or fuse tube components might experience dimensional changes due to environmental factors and/or 2. where the cutout mounting and fuse tube assembly are from different manufacturers which may not be ideally suited to work with each other, i.e. the interfacing, cooperating components are not identical to those for which they were designed.
[0030] In accordance with important aspects of the present invention, additional dropout assistance is provided via a spring 92 carried about the shaft of the bolt 84 , e.g. the shaft of the bolt 84 having a narrowed portion 94 beyond the wider, threaded shaft portion 96 . Ina specific embodiment, the narrowed portion 94 includes a threaded portion 98 for affixing the spring 92 to the bolt 84 . The spring 92 is compressed when the bolt 84 is threaded into the trunnion 68 and tightened to hold the cable 80 . The spring 92 is compressed against an extending tab 100 of the ferrule 72 of the lower ferrule assembly 28 . Accordingly, when the fuse operates and the cable 80 is released, the spring 92 acts to directly rotate the trunnion 68 about the toggle joint 70 to assist in the dropout action of the fuse tube assembly 22 . It should be noted that this assist action is more positive than that of the pivoting of the trunnion 68 due to its being released and also over a wider range and time than that of the release of the flipper 74 .
[0031] Accordingly, the bolt 84 with the spring 92 as an overall assembly 104 performs a dropout assistance function and also functions to retain or clamp the cable 80 to maintain the fuse tube assembly within the upper and lower contact assemblies 18 and 20 . It should also be noted that since every fuse cutout of the type 12 utilizes a bolt such as 84 to clamp the cable 80 , the dropout assistance assembly 104 is capable of easy retrofit in the field merely by substituting the dropout assistance assembly 104 for the conventional bolt for clamping the cable 80 . Further, the desired additional dropout assistance is variable in specific embodiments via the selection of the resilient characteristics of the spring 92 . It will also be clear to those skilled in the art that the leading surface of the spring 92 and/or the extending tab 100 of the ferrule 72 of the lower ferrule assembly 28 should be prepared and/or finished so as to provide unfettered rotation of the spring 92 when tightening the bolt 84 during installation of the fuse link as well as reliable disengagement thereof during operation of the fuse cutout 12 .
[0032] While there have been illustrated and described various embodiments of the present invention, it will be apparent that various changes and modifications will occur to those skilled in the art. Accordingly, it is intended in the appended claims to cover all such changes and modifications that fall within the true spirit and scope of the present invention. | An improved fuse cutout is provided of the type having a fuse tube assembly that moves to a dropout position upon operation in response to a fault current or other overcurrent. These types of fuse cutouts include the pivotal mounting of the fuse tube assembly with respect to a support hinge with the fuse tube assembly being released for pivotal movement to the dropout position when the fuse cutout has operated. The fuse tube assembly includes a collapsible toggle joint that collapses upon operation of the fuse cutout. The improved fuse cutout includes additional dropout assistance that is provided via a resilient member operating between the components of the collapsible toggle joint to apply a force to assist the collapse of the toggle joint. | 7 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a surface modifier for metal oxide particles and a method for modifying the surface of metal oxide particles using the same, and more particularly to a surface modifier consisting either an alkylsilanepolyol containing a cyclic alkyl group capable of imparting steric hindrance or a mixture of said alkylsilanepolyol with alkylalkoxysilane, and to a method of modifying the surface of metal oxide particles by coating the surface modifier on the hydrophilic surface of the metal oxide particles through chemical bonding so as to impart hydrophobicity or amphiphilicity (hydrophilicity and hydrophobicity) and reactivity to the surface of the metal oxide particles.
[0003] 2. Description of the Prior Art
[0004] Usually, materials are classified into three categories: organic, inorganic and metal materials.
[0005] Currently, in order to improve the fundamental physical properties of each of the different materials, complement the shortcomings, maximize the advantages and realize synergistic effects, different materials are hybridized to form, for example, organic/inorganic composite materials. However, one important consideration in hybridization is the technology for controlling the surface polarity of the different materials. This is because effective dispersion is essential to improve the physical properties of different components through mixing. For this purpose, the development of technologies for hybridizing materials after chemically or electrochemically treating the surface of a substrate, coating the surface or treating the surface with a coupling agent is being actively conducted.
[0006] Among materials, inorganic materials receive increasing attention and are used in a wide range of applications, because they have heat resistance, cold resistance, electrical resistance, optical properties, mechanical properties and the like over a wide temperature range compared to other materials and, at the same timer are price competitive. Particularly, because they are porous, and thus have a large internal surface area, they are widely used as adsorbers, packing materials for separation columns, or catalyst carriers.
[0007] In addition, inorganic materials such as titanium dioxide (TiO 2 ) or zinc oxide are used as cosmetic materials or electronic materials because they have the ability to block UV light. However, these powders have a shortcoming in that, when they are used in oily cosmetic products or hydrophobic cosmetic products, which do not easily smear due to sweat or water, they will not be effectively dispersed, and thus their properties will not be sufficiently exhibited.
[0008] Also, these materials are frequently applied in tire compositions, and the surface modification of silica, which is added as an additive during the manufacture of tires in order to reduce the rolling resistance of tires in response to problems of environmental pollution caused by automobiles, to thus increase the fuel economy and the braking power in water or snow, is of increasing importance. However, inorganic particle silica has a hydroxyl group on the surface thereof, and thus is not easily dispersed in non-polar rubbery composite materials due to the cohesive force thereof. For this reason, to date, a silicone binder, a silica dispersing agent and the like have been separately added to tire tread rubber compositions. However, there are problems in that not only a silane binder, but also a silica dispersing agent, must be separately added, alcohol and water, which are solvents, must be removed after surface treatment, and agglomeration occurs due to the hydrolysis and condensation of the silane binder itself in hydrolysis conditions.
[0009] In order to solve a problem in which epoxy molding compounds (EMCs) for protecting semiconductors crack at a temperature higher than 200° C., silica is added to improve the physical properties of EMC. Thus, the effective dispersion of silica which is added in the preparation of EMC is a problem.
[0010] As described above, although inorganic oxides are widely used in various applications, it is difficult to use them in combination with other materials due to a problem in which they are not uniformly dispersed in other materials that require hydrophobicity, because the surface thereof consists of a hydroxyl group (—OH), and is thus hydrophilic. Accordingly, there is the need to develop an effective and easy method of modifying the surface of inorganic particles into a hydrophobic surface to allow the particles to be dispersed uniformly, and then inducing chemical bonding.
[0011] Methods for rendering the surface of inorganic particles hydrophobic can be diverse depending on the kind of inorganic materials, and methods for the surface modification of inorganic materials that are known to date will now be explained briefly.
[0012] In a vapor phase method, low-boiling-point silane with Si—H bond is mainly used, but it has the risk of generating hydrogen gas at high temperature, because it has a silicon-hydrogen (Si—H) bond. In attempts to solve this problem, Korean Patent Laid-Open Publication No. 2004-830 discloses a method of preparing silica directly from a silane-based compound having no silica-hydrogen bond, and Korean Patent Laid-Open Publication No. 2006-128358 discloses a method of modifying a silica surface by heating acrylic silane, and an alkylsilane, having a relatively low boiling point, to a temperature of about 200° C., and spraying the heated materials on the silica surface under pressure. The latter method solves the risk problem, because the silica surface is treated at a relatively low temperature, lower than 200° C., without using a low-boiling-point silane having a silicon-hydrogen bond.
[0013] Also, a wet method for increasing dispersion in non-polar rubber composite materials is known. US Patent Publication No. 2005-020323B discloses a wet method of modifying a silica surface to create a hydrophobic surface by dehydrating the silica surface at high temperature, introducing an alkaline earth metal into the end of a hydrophobic polymer, and allowing the polymer to react with the silica. This method is not a method of simply coating the surface of silica, but is a grafting method of inducing covalent bonding, and has an advantage in that the bonds are significantly stable in subsequent processes. However, because an alkaline earth metal such as lithium or sodium is used, impurities remaining after the reaction are likely to reduce bond stability.
[0014] As other methods, a method of treating cosmetic particles using, as a surface modifier, a polysilane compound having a fluoroester group was reported (Korean Patent Laid-Open Publication No. 2001-19581). However, this method has shortcomings in that the dispersion of the polysilane compound in pigments is not effective and in that the compound should be used in a larger amount than monomolecular compounds. Also, a method of coating the surface of zinc or a zinc alloy with a trialkoxysilane having a primary alkyl group having 3-5 carbon atoms was reported (Korean Patent Laid-Open Publication No. 2004-59977). However, this method has a problem in that the trialkoxysilane is condensed by itself, because steric hindrance cannot be imparted to the primary alkyl group in a hydrolysis step. In addition, methods of treating the surface of inorganic oxides by self-assembly monolayers (SAMs) of octadecyl chlorosilane, alkyl chlorosilane, glycidoxypropyltrimethoxysilane or the like (Tilman, N., Ulman, A., Penner, T. L. Langmuir 1989, 5, 101; Tripp, C. P., Hair, M. L. Langmuir 1992, 8, 1961; Daniels, M. W., Francis, L. F., J. Col. Int. Sci. 1998, 205).
[0015] Although efforts to modify the surface of inorganic materials through various methods as described above have been made, silane compounds used as surface modifiers have been limited mainly to silanes containing a primary alkyl group and tetraalkoxysilanes, and thus there were problems in that unstable silanol groups (Si—OH) are condensed with each other in hydrolysis conditions, or the surface modifier agglomerates before dispersion due to polarity.
SUMMARY OF THE INVENTION
[0016] Accordingly, the present inventors have developed a method of modifying the hydrophilic surface of metal oxide into a hydrophobic surface using an alkylsilanepolyol having a specific chemical structure substituted with a cyclic alkyl group as a functional group capable of inhibiting agglomeration or condensation under hydrolysis conditions, thereby completing the present invention.
[0017] Therefore, it is an object of the present invention to provide the use of an alkylsilanepolyol, having a specific chemical structure substituted with cyclic saturated or unsaturated alkyl groups, as a surface modifier for metal oxide particles.
[0018] Another object of the present invention is to provide a surface modifier for metal oxide particles, which comprises an alkylalkoxysilane compound together with an alkylsilanepolyol, having a specific chemical structure substituted with cyclic saturated or unsaturated alkyl groups and which imparts functionalities such as hydrophobicity or amphiphilicity (hydrophilicity and hydrophobicity) and reactivity.
[0019] Still another object of the present invention is to provide a method of imparting hydrophobicity or amphiphilicity (hydrophilicity and hydrophobicity) and reactivity to the hydrophilic surface of metal oxide particles by coating the hydrophilic surface with a surface modifier composed either of an alkylsilanepolyol having a specific chemical structure substituted with cyclic saturated or unsaturated alkyl groups or of a mixture of said alkylsilanepolyol and an alkylalkoxysilane compound, through chemical bonding.
[0020] To achieve the above objects, the present invention provides a surface modifier for metal oxide particles, which comprises an alkylsilanepolyol represented by the following formula 1:
[0000] RR 1 Si(OH) 2 [Formula 1]
[0021] wherein R is a cyclic saturated or unsaturated C 2-8 alkyl group which can be substituted with a hydrogen atom or a C 1-6 alkyl group, and R 1 is an OH or SiR(OH) 2 group.
[0022] In another aspect, the present invention provides a method for modifying the surface of metal oxide particles, the method comprising: dispersing metal oxide powder and said alkylsilanepolyol of the formula 1 in a solvent selected from among water and alcohols having 1 to 6 carbon atoms; evaporating the solvent from the dispersion to obtain metal oxide particles coated with alkylsilanepolyol; and thermally treating the coated metal oxide particles at a temperature of 100-130° C. to obtain metal oxide particles having alkylsilanepolyol chemically bonded to the surface thereof.
BRIEF DESCRIPTION OF THE DRAWINGS
[0023] The above and other objects, features and advantages of the present invention will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings, in which:
[0024] FIG. 1 illustrates electron microscope photographs showing silica particles before surface treatment and silica particles subjected to surface treatment in Example 1;
[0025] FIG. 2 shows the results of infrared spectrometry for silica particles subjected to surface treatment in Example 1;
[0026] FIG. 3 shows the comparison between silica particles before surface treatment and silica particles subjected to surface treatment in Example 1;
[0027] FIG. 4 illustrates electron microscope photographs showing titanium dioxide particles before surface treatment and titanium dioxide particles subjected to surface treatment in Example 13; and
[0028] FIG. 5 illustrates electron microscope photographs showing zirconium dioxide particles before surface treatment and zirconium dioxide particles subjected to surface treatment in Example 14.
DETAILED DESCRIPTION OF THE INVENTION
[0029] Hereinafter, the present invention will be described in detail.
[0030] The present invention is technically characterized in that an organosilane polyol having a specific structure is used instead of an alkoxysilane, which was used as a surface modifier for metal oxide in the prior art. That is, the alkylsilanepolyol represented by formula 1, which is used as a surface modifier for metal oxide in the present invention, is characterized in that it is substituted with a secondary cyclic alkyl group capable of imparting steric hindrance, and thus the secondary alkyl group interferes with the chemical bonding of the alkylsilanepolyol itself to inhibit the agglomeration of the alkylsilanepolyol. Also, it is characterized in that the secondary alkyl group promotes the stabilization of silicon-hydroxyl (Si—OH) bonds to form a surface thin film through hydrogen bonds with the hydrophilic surface of metal oxide particles, and these hydrogen bonds are condensed in a high temperature condensation process to form Si—O-M covalent bonds. Moreover, because the alkylsilanepolyol represented by the formula 1 has high solubility in polar solvents such as water or alcohol, no separate additive for dispersing the alkylsilanepolyol uniformly is used, and the alkylsilanepolyol can form a uniform coating layer by forming covalent bonds via a condensation reaction with metal oxide even through a simple heating process. Particularly, when water is used as solvent, the inventive method can become a very environmentally-friendly surface treatment method. In addition, there is an advantage in that a condensation reaction can be performed in a low-boiling-point solvent without using a vapor phase method.
[0031] In the alkylsilanepolyol represented by the formula 1, R is preferably cyclopentyl, cyclohexanyl, cyclopenten-1-yl, cyclopenten-2-yl, cyclopenten-3-yl, cyclohexen-1-yl, cyclohexen-2-yl, cyclohexen-3-yl, 3-methyl-cyclohexen-3-yl, 4-methyl-cyclohexen-3-yl, or 3,4-dimethyl-cyclohexen-3-yl.
[0032] More specific examples of the alkylsilanepolyol represented by the formula 1, which is used in the present invention, may include cyclopentylsilanetriol, cyclohexanylsilanetriol, cyclopenten-1-ylsilanetriol, cyclopenten-2-ylsilanetriol, cyclopenten-3-ylsilanetriol, cyclohexen-1-ylsilanetriol, cyclohexen-2-ylsilanetriol, cyclohexen-3-ylsilanetriol, 3-methyl-cyclohexen-3-ylsilanetriol, 4-methyl-cyclohexen-3-ylsilanetriol, 3,4-dimethyl-cyclohexen-3-ylsilanetriol, 1,2-dicyclohexyl-1,1,2,2-tetrahydroxydisilane, 1,2-bis(cyclohexen-3-yl)-1,1,2,2-tetrahydroxydisilane, 1,2-bis(3-methyl-cyclohexen-3-yl)-1,1,2,2-tetrahydroxydisilane, 1,2-bis(4-methyl-cyclohexen-3-yl)-1,1,2,2-tetrahydroxydisilane, 1,2-bis(3,4-dimethyl-cyclohexen-3-yl)-1,1,2,2-tetrahydroxydisilane and the like.
[0033] The alkylsilanepolyol represented by formula 1 is used in an amount of 0.01-20 wt %, and preferably 0.1-10 wt %, based on the weight of the metal oxide.
[0034] Also, the present invention is characterized in that, in addition to the alkylsilanepolyol represented by formula 1, an alkylalkoxysilane represented by the following formula 2 is used as a surface modifier for metal oxide particles to impart hydrophobicity and reactivity to the surface of the metal oxide particles:
[0000] R 3 Si(OR 2 ) 3 [Formula 2]
[0035] wherein R 2 is a C 1-6 alkyl group; and R 3 is 3-(glycidoxy)propyl, 2-(3,4-epoxycyclohexyl)ethyl, 3,3,3-trifluoropropyl, 3-[3-(triethoxysilyl)propyltetrathio]propyl, 3-[3-(trimethoxysilyl)propyltetrathio]propyl, 3-[3-(triethoxysilyl)propyldithio]propyl, 3-[3-(trimethoxysilyl)propyldithio]propyl, 3-aminopropyl, N-(2-aminoethyl)-3-aminopropyl, 3-acryloxypropyl, 3-methacryloxypropyl, 2-cyanoethyl, 3-cyanopropyl, 3-isocyanatopropyl, 3-mercaptopropyl, 3-(methacryloxy)propyl, CF 3 (CF 2 ) n CH 2 CH 2 , wherein n is an integer from 0 to 10, 2-(3-hexenyl)ethyl, or a terminal alkenyl group.
[0036] The alkylalkoxysilane represented by formula 2 may be included as a surface modifier to impart functionalities, such as hydrophobicity, amphiphilicity (hydrophilicity and hydrophobicity) and reactivity, to the surface of the metal oxide particles. Specific examples of the alkylalkoxysilane represented by the formula 2 may include 3-glycidoxypropyltriethoxysilane, 3-glycidoxypropyltrimethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltriethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3,3,3-trifluoropropyltriethoxysilane, 3,3,3-trifluoropropyltrimethoxysilane, bis(3-triethoxysilylpropryl)tetrasulfide, bis(3-trimethoxysilylpropryl)tetrasulfide, bis(3-triethoxysilylpropryl)disulfide, bis(3-trimethoxysilylpropryl)disulfide, 3 aminopropyltriethoxysilane, 3-aminopropyltrimethoxysilane, N-(2-aminoethyl)-3-aminopropyltrimethoxysilane, N-(2-aminoethyl)-3-aminopropyltriethoxysilane, 3-acryloxypropyltrimethoxysilane, 3-acryloxypropyltriethoxysilane, 3-(methacryloxy)propyltriethoxysilane, 3-(methacryloxy)propyltrimethoxysilane, 2-cyanoethyltriethoxsilane, 2-cyanoethyltrimethoxysilane, 3-cyanopropyltriethoxysilane, 3-cyanopropyltrimethoxysilane, 3-isocyanatopropyltriethoxysilane, 3-isocyanatopropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane, 3-mercaptopropyltrimethoxysilane, CF 3 (CF 2 ) n CH 2 CH 2 —Si(OCH 2 CH 3 ) 3 wherein n is an integer ranging from to 10, and preferably from 0 to 4, CF 3 (CF 2 ) n CH 2 CH 2 —Si(OCH 2 ) 3 wherein n is an integer ranging from 0 to 10, and preferably from 0 to 4,2-(3-hexenyl)ethyltriethoxysilane, 2-(3-hexenyl)ethyltrimethoxysilane, ethoxysilane having a terminal alkenyl group, and the like.
[0037] The alkylalkoxysilane represented by the formula 2 is used in an amount of less than 20 wt %, and preferably 0.1-10 wt %, based on the weight of metal oxide.
[0038] Also, the surface modifier of the present invention may additionally contain an aqueous acetic acid solution as a catalyst. When the aqueous acetic acid solution has an acetic acid concentration of 1 wt %, it is preferably used in an amount of 1-5 wt % based on the weight of the metal oxide.
[0039] Meanwhile, the scope of the present invention encompasses a method of modifying the surface of the metal oxide particles using the above-described surface modifier.
[0040] The surface modification method according to the present invention comprises the steps of:
[0041] i) uniformly dispersing metal oxide powder and alkylsilanepolyol, represented by the formula 1, in a solvent selected from among water and alcohols having 1 to 6 carbon atoms; ii) dispersing the solvent from the dispersion to obtain metal oxide particles coated with alkylsilanepolyol; and (iii) drying and condensing the coated metal oxide particles at a temperature of 100-130° C. to obtain metal oxide particles having alkylsilanepolyol chemically bonded to the surface thereof.
[0042] In the surface modification method according to the present invention, the alkylalkoxysilane represented by the formula 2, in addition to the alkylsilanepolyol represented by the formula 1, may be included in the solvent to impart various functionalities to the surface of metal oxide particles.
[0043] Metal oxides, to which the surface modifier according to the present invention is applied, are in a powder state in which a mean particle size ranges from 5 nm to 100 μm. These metal oxides are inorganic materials which are frequently used as fillers in the art, and examples thereof may include wet or dry silica, mica, talc, titanium oxide, zirconium oxide, tin oxide, iron oxide, zinc oxide and the like. This surface modifier of the present invention can also be applied using a method for modifying the surface of a substrate such as a silicon wafer.
[0044] Each step of the surface modification method according to the present invention will now be described in further detail.
[0045] The step i) is a process of uniformly dispersing metal oxide powder and the surface modifier. The metal oxide powder is used after it is dried and dehydrated using, for example, a dryer. As the surface modifier, the alkylsilanepolyol represented by the formula 1 is used alone or in combination with the alkylalkoxysilane represented by the formula 2. For uniform dispersion of the metal oxide powder and the surface modifier, a solvent selected from among water and alcohol having 1 to 6 carbon atoms is used in the present invention. In this case, uniform dispersion can be achieved, because the silane compound represented by the formula 1 or 2, which is used as the surface modifier in the present invention, has high solubility in water and alcohol solvents.
[0046] If necessary, an aqueous acetic acid solution may also be added as a catalyst. When the aqueous acetic acid solution has an acetic acid concentration of 1 wt %, it is preferably added in an amount of 1-5 wt % based on the weight of the metal oxide powder.
[0047] The step ii) is a process of obtaining metal oxide particles coated with alkylsilanepolyol. That is, the solvent is removed from the above-prepared dispersion using a rotary evaporator to obtain metal oxide particles coated with alkylsilanepolyol. Herein, the organosilane polyol forms hydrogen bonds with the hydroxyl groups on the surface of the metal oxide particles, or is adsorbed on the surface thereof depending to the polarity thereof.
[0048] The step iii) is a process of thermally treating the coated metal oxide particles obtained in the above step such that the alkylsilanepolyol coated on the surface of the particles forms a thin film on the metal oxide particles through, for example, chemical covalent bonds. The thermal treatment is carried out at a temperature of 100-130° C.
[0049] Hereinafter, the present invention will be described in further detail with reference to the following examples, but the scope of the present invention is not limited to these examples.
EXAMPLES
Example 1
Treatment of Silica (SiO 2 ) Surface with Cyclopentenylsilanetriol
[0050] In a 250-ml round bottom flask, 10 g of wet silica selected from among 150 m 2 /g Aerosil® (Degussa, 15 nm, 140-80 m 2 /g, Aldrich, 99.5%), 175 m 2 /g ZEOSIL® 175GR and 115 m 2 /g ZEOSIL® 115GR (Rodia) was stirred and dispersed in 50 ml of water. To the dispersion, a solution of 1.0 g of cyclopentenylsilanetriol dissolved in water was added dropwise over 10 minutes and stirred. Water was removed from the dispersion to the greatest possible extent using a rotary evaporator, and the remaining material was dried in a vacuum oven at 130° C. for 6 hours. In order to examine the state of the silica particles before and after treatment, the silica particles were analyzed with an electron microscope, and the analysis results are shown in FIG. 1 .
[0051] Also, the surface-treated silica was analyzed by infrared spectrometry using DRIFT (diffuse reflectance FR-IR) as an infrared spectrometer and MCT (mercury-cadmium-telluride) as a detector. The results of the infrared spectrometry are shown in FIG. 2 . As can be seen in FIG. 2 , characteristic absorption peaks were observed at 2929 cm −1 (asym, C—H stretching), 2857 cm −1 (sym, C—H stretching) and 1457 cm −1 (C—H bend). For reference, negative broad bands appearing between 1150 cm −1 and 1050 cm −1 were considered to be attributable to S is —O—Si [Hair, M. L., Tripp, C. P., Langmuir, 1991, 7, 923].
[0052] The silica particles before surface treatment and the silica particles after surface treatment were compared with each other after they were shaken in water and then left to stand for 1 hour. As can be seen from the photographs in FIG. 3 , the silica particles before surface treatment settled down within a few minutes, and the silica particles after surface treatment floated in the water, because they were modified into hydrophobic particles.
Example 2
Treatment of Silica (SiO 2 ) Surface with Cyclopentenylsilanetriol
[0053] In a flask, 10 g of the same wet silica (dried at 120° C. for 8 hours) as used in Example 1 was stirred and dispersed in 50 ml of methanol. Then, a solution of 1.0 g of cyclopentenylsilanetriol dissolved in methanol at 0° C. was added dropwise to the flask at 0° C. and stirred for 10 minutes. The solvent was removed to the greatest possible extent using a rotary evaporator, and the remaining material was dried in a vacuum oven at 130° C. for 6 hours.
Example 3
Treatment of Silica (SiO 2 ) Surface with Cyclopentenylsilanetriol and bis(3-triethoxysilylpropyl)tetrasulfide
[0054] In a flask, 10 g of the same wet silica (dried at 120° C. for 8 hours) as used in Example 1 was dispersed in 50 ml of methanol. Then, 0.5 g of cyclopentenylsilanetriol and 0.5 g of bis(3-triethoxysilylpropyl)tetrasulfide (Degussa Germany, Si69) were added dropwise to the flask and stirred for 10 minutes. The solvent was removed to the greatest possible extent using a rotary evaporator, and the remaining material was dried in a vacuum oven at 130° C. for 6 hours. In this Example, 1 ml of 1 wt % acetic acid aqueous solution as a catalyst was added dropwise to the dispersion and, as a result, the surface modification of the metal oxide was more effectively conducted.
Example 4
Treatment of Silica (SiO 2 ) Surface with Cyclopentenylsilanetriol and 3-mercaptopropyltriethoxysilane
[0055] In a flask, 10 g of the same wet silica (dried at 120° C. for 8 hours) as used in Example 1 was dispersed in 50 ml of methanol. Then, 0.5 g of cyclopentenylsilanetriol and 0.5 g of 3-mercaptopropyltriethoxysilane (Gelest, Inc.) were added dropwise to the flask and stirred for 10 minutes. The solvent was removed to the greatest possible extent using a rotary evaporator, and the remaining material was dried in a vacuum oven at 130° C. for 6 hours.
Example 5
Treatment of Silica (SiO 2 ) Surface with cyclopentenylsilanetriol and 3-(glycidoxy)propyltriethoxysilane
[0056] 10 g of the same wet silica (dried at 120° C. for 8 hours) as used in Example 1, 50 ml of methanol, 0.5 g of cyclopentenylsilanetriol and 0.5 g of 3-(glycidoxy)propyltriethoxysilane were added dropwise to a flask and stirred for 10 minutes. The solvent was removed to the greatest possible extent using a rotary evaporator, and the remaining material was dried in a vacuum oven at 130° C. for one day. In this Example, 1 ml of 1 wt % acetic acid aqueous solution as a catalyst was added dropwise to the dispersion and, as a result, the surface modification of the metal oxide was more effectively conducted.
Example 6
Treatment of Silica (SiO 2 ) Surface with Cyclopentenylsilanetriol and 2-(3,4-epoxycyclohexyl)ethyltriethoxysilane
[0057] 10 g of the same wet silica (dried at 120° C. for 8 hours) as used in Example 1, 50 ml of methanol, 0.50 g of cyclopentenylsilanetriol and 0.50 g of 2-(3,4-epoxycyclohexyl)ethyltriethoxysilane were added dropwise to a flask and stirred for 10 minutes. The solvent was removed to the greatest possible extent using a rotary evaporator, and the remaining material was dried in a vacuum oven at 130° C. for one day. In this Example, 1 ml of 1 wt % acetic acid aqueous solution as a catalyst was added dropwise to the dispersion and, as a result, the surface modification of the metal oxide was more effectively conducted.
Example 7
Treatment of Silica (SiO 2 )— Surface with Cyclopentenylsilanetriol and 3-(methacryloxy)propyltriethoxysilane
[0058] 10 g of the same wet silica (dried at 120° C. for 8 hours) as used in Example 1, 50 ml of methanol, 0.50 g of cyclopentenylsilanetriol and 0.50 g of 3-(methacryloxy)propyltriethoxysilane were added dropwise to a flask and stirred for 10 minutes. The solvent was removed to the greatest possible extent using a rotary evaporator, and the remaining material was dried in a vacuum oven at 130° C. for one day.
Example 8
Treatment of Silica (SiO 2 ) Surface with Cyclopentenylsilanetriol and 3-isocyanatopropyltrimethoxysilane
[0059] 10 g of the same wet silica (dried at 120° C. for 8 hours) as used in Example 1, 50 ml of methanol, 0.50 g of cyclopentenylsilanetriol and 0.50 g of 3-isocyanatopropyltrimethoxysilane were added dropwise to a flask and stirred for 10 minutes. The solvent was removed to the greatest possible extent using a rotary evaporator, and the remaining material was dried in a vacuum oven at 130° C. for one day.
Example 9
Treatment of Silica (SiO 2 ) Surface with Cyclopentenylsilanetriol and 3-isocyanatopropyltriethoxysilane
[0060] 10 g of the same wet silica (dried at 120° C. for 8 hours) as used in Example 1, 50 ml of methanol, 0.50 g of cyclopentenylsilanetriol and 0.50 g of 3-isocyanatopropyltriethoxysilane were added dropwise to a flask and stirred for 10 minutes. The solvent was removed to the greatest possible extent using a rotary evaporator, and the remaining material was dried in a vacuum oven at 130° C. for one day.
Example 10
Treatment of Silica (SiO 2 ) Surface with Cyclopentenylsilanetriol and 3-aminopropyltriethoxysilane
[0061] 10 g of the same wet silica (dried at 120° C. for 8 hours) as used in Example 1, 50 ml of methanol, 0.50 g of cyclopentenylsilanetriol and 0.50 g of 3-aminopropyltriethoxysilane were added dropwise to a flask and stirred for 10 minutes. The solvent was removed to the greatest possible extent using a rotary evaporator, and the remaining material was dried in a vacuum oven at 130° C. for one day.
Example 11
Treatment of Silica (SiO 2 ) Surface with Cyclopentenylsilanetriol and CF 3 (CF 2 ) n CH 2 CH 2 —Si(OCH 2 CH 3 ) 3 (n=0)
[0062] 10 g of the same wet silica (dried at 120° C. for 8 hours) as used in Example 1, 50 ml of methanol, 0.50 g of cyclopentenylsilanetriol and 0.50 g of CF 3 (CF 2 ) n CH 2 CH 2 —Si(OCH 2 CH 3 ) 3 (n=0) were added dropwise to a flask and stirred for 10 minutes. The solvent was removed to the greatest possible extent using a rotary evaporator, and the remaining material was dried in a vacuum oven at 130° C. for one day. In this Example, 1 ml of 1 wt % acetic acid aqueous solution as a catalyst was added dropwise to the dispersion and, as a result, the surface modification of the metal oxide was more effectively conducted.
Example 12
Treatment of Silica (SiO 2 ) Surface with Cyclopentenylsilanetriol and 2-(3-hexenyl)ethyltriethoxysilane
[0063] 10 g of the same wet silica (dried at 120° C. for 8 hours) as used in Example 1, 50 ml of methanol, 0.50 g of cyclopentenylsilanetriol and 0.50 g of 2-(3 hexenyl)ethyltriethoxysilane were added dropwise to a flask and stirred for 10 minutes. The solvent was removed to the greatest possible extent using a rotary evaporator, and the remaining material was dried in a vacuum oven at 130° C. for one day. In this Example, 1 ml of 1 wt % acetic acid aqueous solution as a catalyst was added dropwise to the dispersion and, as a result, the surface modification of the metal oxide was more effectively conducted.
Example 13
Treatment of Titanium Dioxide (TiO 2 ) Surface with Cyclopentenylsilanetriol
[0064] 10 g of titanium dioxide (Aldrich, 99.8%) was treated with 1.0 g of cyclopentenylsilanetriol according to the same method described in Example 2. The titanium dioxide particles before and after surface treatment were observed under an electron microscope, and the observation results are shown in FIG. 4 .
Example 14
Treatment of Zirconium Dioxide (ZrO 2 ) Surface with Cyclopentenylsilanetriol
[0065] 10 g of zirconium dioxide (sigma-Aldrich, 1 μm, 99%) was treated with 1.0 g of cyclopentenylsilanetriol according to the same method described in Example 2. The zirconium dioxide particles before and after surface treatment were observed with an electron microscope, and the observation results are shown in FIG. 5 .
Example 15
Treatment of Zirconia (ZrO 2 ) Surface with Cyclopentylsilanetriol
[0066] 10 g of zirconium dioxide (Sigma-Aldrich, 1 μm, 99%) was treated with 1.0 g of cyclopentenylsilanetriol according to the same method described in Example 2, thus preparing surface-modified zirconia.
Example 16
Treatment of Silica (SiO 2 ) Surface with Cyclopentylsilanetriol
[0067] The same silica as used in Example 1 was treated cyclopentylsilanetriol instead of cyclopentenylsilanetriol in the same manner as described in Example 1. The results obtained in this Example were similar to those in Example 1.
Example 17
Treatment of Silica (SiO 2 ) Surface with Cyclopentylsilanetriol
[0068] 10 g of the same silica used in Example 1 was added to an aqueous solution of 1.0 g of cyclopentylsilanetriol, prepared by hydrolyzing cyclopentyl trimethoxysilane according to the method of Korean Patent Application No 2007-106843, filed in the name of the present applicant. The mixture was stirred, while water and methanol (hydrolysis product) were evaporated therefrom. The remaining material was dried in a vacuum oven at 130° C. for one day. All of the treated silica particles were observed to float in water, because they had been modified into hydrophobic particles.
Example 18
Treatment of Silica (SiO 2 ) Surface with Cyclohexanylsilanetriol
[0069] The same wet silica used in Example 1 was treated with a solution of cyclohexanylsilanetriol dispersed in methanol, according to the same method described in Example 2. All of the treated silica particles were observed to float in water, because they had been modified into hydrophobic particles.
Example 19
Treatment of Silica (SiO 2 ) Surface with 3-methyl-3-cyclohexenylsilanetriol
[0070] The same wet silica used in Example 1 was treated with a solution of 3-methyl-3-cyclohexenylsilanetriol dispersed in methanol, according to the same method as described in Example 2. All of the treated silica particles were observed to float in water, because they had been modified into hydrophobic particles.
Example 20
Treatment of Silica (SiO 2 ) Surface with 4-methyl-3-cyclohexenylsilanetriol
[0071] The same wet silica used in Example 1 was treated with a solution of 4-methyl-3-cyclohexenylsilanetriol dispersed in methanol, according to the same method as described in Example 2. All of the treated silica particles were observed to float in water, because they had been modified into hydrophobic particles.
Example 21
Treatment of silica (SiO 2 ) surface with 3,4-dimethyl-3-cyclohexenylsilanetriol
[0072] The same wet silica used in Example 1 was treated with a solution of 3,4-dimethyl-3-cyclohexenylsilanetriol dispersed in methanol, according to the same method as described in Example 2. All of the treated silica particles were observed to float in water, because they had been modified into hydrophobic particles.
Example 22
Treatment of Silica (SiO 2 ) Surface with 1,2-dicyclohexyl-1,1,2,2-tetrahydroxydisilane
[0073] The same wet silica used in Example 1 was treated with a solution of 1,2-dicyclohexyl-1,1,2,2-tetrahydroxydisilane dispersed in methanol, according to the same method as described in Example 2. All of the treated silica particles were observed to float in water, because they had been modified into hydrophobic particles.
Example 23
Treatment of Silica (SiO 2 ) Surface with 1,2-bis(cyclohexen-3-yl)-1,1,2,2-tetrahydroxydisilane
[0074] The same wet silica used in Example 1 was treated with a solution of 1,2-bis(cyclohexen-3-yl)-1,1,2,2-tetrahydroxydisilane dispersed in methanol, according to the same method as described in Example 2. All of the treated silica particles were observed to float in water, because they had been modified into hydrophobic particles.
Example 24
Treatment of Silica (SiO 2 ) Surface with Mixture of Cyclopentylsilanetriol and 1,2-dicyclopentyl-1,1,2,2-tetrahydroxydisilane
[0075] Cyclopentylsilanetriol, obtained by hydrolyzing cyclopentyl trimethoxysilane, was mixed with 1,2-dicyclopentyl-1,1,2,2-tetrahydroxydisilane at a molar ratio of 1:4. 10 g of the same silica used in Example 1 was added to 1.0 g of the mixture and stirred, while water and methanol (hydrolysis product) were evaporated therefrom. The remaining material was dried in a vacuum oven at 130° C. for one day. All of treated silica particles were observed to float in water, because they had been modified into hydrophobic particles.
Example 25
Treatment of Silica (SiO 2 ) Surface with Aqueous Solution of Cyclopentenylsilanetriol
[0076] In a flask, 10 g of the same wet silica (11 nm, 225 m 2 /g, Aldrich) used in Example 2 was stirred and dispersed in 50 ml of methanol. Then, 3.0 g of cyclopentenylsilanetriol dispersed in methanol at 0.0° C. was added dropwise to the flask at 0° C. and stirred for 10 minutes. The solvent was removed to the greatest possible extent using a rotary evaporator, and the remaining material was dried in a vacuum oven at 130° C. for 6 hours. All of the treated silica particles were observed to float in water, because they had been modified into hydrophobic particles.
Example 25
Treatment of Silica (SiO 2 ) Surface with Hydrolysate of (2-cyclopentenyl)trimethoxysilane
[0077] At atmospheric pressure and room temperature, 0.65 ml of 1 wt % acetic acid aqueous solution was placed in a 50-ml glass flask, and 0.65 ml of (2-cyclopentenyl)trimethoxysilane was added thereto with stirring. After hydrolysis at 25° C. for 1 hour, the solution became completely clear (complete conversion to silanetriol). Then, the solution and 10 g of the same silica used in Example 1 were stirred and dispersed in 50 ml of methanol. Then, the solvent was removed to the greatest possible extent using a rotary evaporator, and the remaining material was dried in a vacuum oven at 130° C. for 6 hours. The results obtained in this Example were similar to those in Example 2.
[0078] As described above, according to the present invention, the surface of nanometer-sized, functional metal oxide can be modified using, as a modifier, an organosilane polyol substituted with a specific functional group imparting steric hindrance. The surface-modified functional metal oxide particles can be widely used to, for example, impart functionality to various organic composites and improve the performance of the composites.
[0079] Although the preferred embodiment of the present invention has 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. | Disclosed herein are a surface modifier for metal oxide particles and a method of modifying the surface of metal oxide particles using the same. The surface modifier consists either of an alkylsilanepolyol containing a cyclic alkyl group capable of imparting steric hindrance or of a mixture of said alkylsilanepolyol with alkylalkoxysilane, and the method of modifying the surface of metal oxide particles comprises coating the surface modifier on the hydrophilic surface of the metal oxide particles through chemical bonding so as to impart hydrophobicity or amphiphilicity (hydrophilicity and hydrophobicity) and reactivity to the surface of the metal oxide particles. Through the use of alkylsilane triol having a specific chemical structure, surface-modified metal particles having uniform particle size distribution can be provided not only by inhibiting the condensation and agglomeration of the surface modifier itself during a high-temperature condensation reaction for inducing the chemical bonding between metal oxide and the modifier, but also by stabilizing silicon-hydroxyl (Si—OH) bonds. | 2 |
BACKGROUND OF THE INVENTION
[0001] The use of certain genetically modified myxoma viruses for treating cancer is disclosed in WO 04/078206 (Robarts Research Institute).
SUMMARY OF THE INVENTION
[0002] This invention relates to Myxoma viruses (MV) that are deficient in the activity of a Myxoma virus protein selected from the group consisting of M11L, M063, M136, M-T4 and M-T7. Such viruses are used in a method for and in the manufacture of a medicament for, inhibiting a cancer cell, which method comprises administering to the cell an effective amount of the Myxoma virus. They are also used in a method for and in the manufacture of a medicament for, treating a human subject having cancer, comprising administering to the patient an effective amount of the Myxoma virus. This invention also provides a pharmaceutical composition comprising such Myxoma viruses and a pharmaceutically acceptable carrier, as well as a kit comprising such Myxoma viruses and instructions for treating a cancer patient.
DESCRIPTION OF THE FIGURES
[0003] FIG. 1 . Endogenous activated Akt levels in human glioma cells.
[0004] FIG. 2 . Viral replication efficiency of the various vMyx-hrKOs and controls in human glioma cell lines.
[0005] FIG. 3 . Secreted early and late viral gene expression indicates that some of the vMyx-hrKO are unable to transit from early to late gene expression.
[0006] FIG. 4 . Selected single step growth curves.
[0007] FIG. 5 . Cell-based cytotoxicity assay.
DETAILED DESCRIPTION OF THE INVENTION
[0008] WO 04/078206 (Robarts Research Institute) discloses the use of certain genetically modified myxoma viruses for treating cancer. This invention represents an advance by providing more specific modified myxoma viruses for such uses. The techniques disclosed therein are applicable generally to the myxoma viruses of this invention and the contents of WO 04/078206 are incorporated herein by reference.
[0009] As used herein “deficient in the activity of” a given Myxoma virus protein means that the virus has less of the activity in question than wild-type Myxoma virus. “Substantially no activity” of a given viral protein means that the virus has no detectable level of such activity. Examples of Myxoma viruses having substantially no activity of a given viral protein include mutants in which the gene for such protein has been deleted or otherwise knocked-out.
[0010] In accordance with this invention, any kind of cancer or cancer cell can be inhibited or treated. In an embodiment of this invention, the cancer cell is a mammalian cancer cell. In a more specific embodiment, the cancer cell is a human cancer cell. Examples of such human cancer cells include gliomas.
[0011] It has been demonstrated that wild-type myxoma virus (vMyxgfp) can produce a productive, long-lived infection, and destroy and clear implanted tumor tissue when injected intratumorally into human gliomas implanted in murine brains (Lun et al, 2005 Cancer Research 65:9982-9990). As well, a screen of the NCI-60 reference collection indicated that MV productively infects the majority (15/21) of human tumor cells tested (Sypula et al. 2004 Gene Ther. Mol. Biol. 8:103-114). To expand understanding of MV tropism in cancer cells, a series of human glioma cells (U87, U118, U251, U343, U73) that were previously tested for wild-type MV permissiveness were screened. These findings have been extended in the following Examples by testing the infection and replication of several MV viruses in which specific host range genes, identified as having a role in defining MV tropism in rabbit cells, have been deleted. These viruses are collectively referred to as host range knockouts (vMyx-hrKO). Variation was observed in the ability of various vMyx-hrKOs to replicate and spread in the human glioma cells. vMyxT2(U251), vMyxT4KO (U87, U118, U251 and U373) and vMyxT5KO (U251, U373) exhibited some restriction in specific human gliomas. In contrast vMyx63KO and vMyx135KO appeared to replicate and kill more effectively in several of the gliomas.
[0012] The invention will be better understood by reference to the following examples, which illustrate but do not limit the invention described herein.
EXAMPLES
Example 1
[0013] Fifty micrograms of whole cell lysates were probed with antibodies against phosphorylated Akt at positions threonine 308 (P-Akt T308) and serine 473 (P-Akt 5473) or total Akt. Based on the levels of activated Akt U87 and U343 would be expected to be infectable and U118, U251 and U373 to be more resistant to MV infection. ( FIG. 1 ).
Example 2
[0014] Virus stocks were titrated on the various glioma cells and control BGMK or RK13 cells. Virus titres, derived from the gliomas, were compared to the control levels and a value of viral replication efficiency was estimated. Based on these results none of the gliomas supported viral growth to the levels observed in the control lines. However some viruses (vMyx135KO, vMyx63KO and vMyx136KO) were more efficient than other knockouts. As well, some glioma lines supported more replication (U87, U343 and U373). ( FIG. 2 ).
Example 3
[0015] Various human gliomas were infected with a range of vMyx-hrKOs. Twenty hpi the infected supernatants were collected and concentrated 10×. Fifteen microlitres of concentrated sups were separated on a 12% SDS-PAGE gel and probed with anti-Serp1 (mAB; late MV gene product). The blots were stripped and probed for early gene expression with anti-M-T7 (pAB; early MV gene product). The results suggest that several vMyx-hrKOs are restricted in their transit from early to late gene expression including vMyxT2KO, vMyxT4KO and vMyxT5KO. And in two glioma lines (U87 and U37), vMyxT4KO does not even undergo early gene expression. ( FIG. 3 ).
Example 4
[0016] Cells were seeded in 48 well dishes and infected cells were collected at the times indicated. Virus was released from the collected cell pellets and titrated back onto BGMK cells. Although there was replication of the tested viruses, the best amplification appeared to occur in the U87 and U343 cells. ( FIG. 4 ).
Example 5
[0017] The ability of the various vMyx-hrKOs and control viruses to have a killing effect in the panel of human gliomas was tested by a cytotoxicity assay. The appropriate cells were seeded in 96 well dishes and 24 h later were infected with the viruses at various MOTs. Seventy-two hours post infection the infected cells were treated with the WTS reagent (Roche) to measure cell viability. Colour changes were measured at 450 nm every 60 minutes for 4 hours. Uninfected control wells were used to determine normal proliferation and a blank well served as a background control. ( FIG. 5 ). | Myxoma viruses that are deficient in the activity of a Myxoma virus protein selected from the group consisting of M11L, M063, M 136, M-T4 and M-T7 are useful for treating cancer. | 2 |
CROSS-REFERENCE TO RELATED APPLICATION
The present application is a continuation-in-part of U.S. application Ser. No. 13/448,060 filed Apr. 16, 2012 now abandoned, and claims the benefit thereof.
BACKGROUND
The present invention relates to packer, bridge plug and frac plugs type tools used in wellbores and more particularly to retaining assemblies, such as extrusion limiters or retaining shoes, used in packer and bridge plug type tools.
In the drilling or reworking of oil wells, a great variety of downhole tools are used. For example, but not by way of limitation, it is often desirable to seal tubing or other pipe in the casing of the well, such as when it is desired to pump cement or other slurry down the tubing and force the cement or slurry around the annulus of the tubing or out into a formation. It then becomes necessary to seal the tubing with respect to the well casing and to prevent the fluid pressure of the slurry from lifting the tubing out of the well or for otherwise isolating specific zones in a well. Downhole tools referred to as packers and bridge plugs are designed for these general purposes and are well known in the art of producing oil and gas.
When it is desired to remove many of these downhole tools from a wellbore, it is frequently simpler and less expensive to mill or drill them out rather than to implement a complex retrieving operation. In milling, a milling cutter is used to grind the packer or plug, for example, or at least the outer components thereof, out of the wellbore. In drilling, a drill bit is used to cut and grind up the components of the downhole tool to remove it from the wellbore. This is a much faster operation than milling, but requires the tool to be made out of materials that can be accommodated by the drill bit. To facilitate removal of packer type tools by milling or drilling, packers and bridge plugs have been made, to the extent practical, of non-metallic materials such as engineering grade plastics and composites.
Packer tools and other wellbore isolation devices sometimes have elements that undesirably protrude radially and inadvertently contact a wellbore, a casing within a wellbore, or other object. Such contact sometimes results in damage to the packer tool and/or premature transitioning of the device from a run in configuration to a set configuration. For example, some conventional slip segments of wellbore isolation devices are held together somewhat tightly against a mandrel through the use of one or more bands. The bands may be intended to stretch or fracture when the tool is activated in order to allow deployment. However, the bands often protrude radially and, thus, offer limited resistance to inadvertent deployment when the wellbore isolation device undergoes inadvertent perturbation.
SUMMARY
The present invention provides a downhole apparatus that is more resistant to inadvertent deployment than prior art downhole apparatuses.
In one embodiment of the invention there is provided a downhole apparatus for use in a wellbore. The apparatus has a mandrel having a longitudinal axial centerline and a radial direction perpendicular to the longitudinal axial centerline. A sealing assembly is disposed about the mandrel. The sealing assembly is radially expandable from an unset position to a set position in response to the application of axial force on the sealing assembly. In the set position the sealing assembly engages the wellbore. The invention also includes at least one retaining assembly for retaining the sealing assembly and resisting extrusion of the sealing assembly. The retaining assembly is proximate to the sealing assembly and has a plurality of segments disposed about the mandrel. The plurality of segments is adapted to resist extrusion of the sealing assembly and adapted to expand radially to engage the wellbore when the sealing assembly is in the set position. When the sealing assembly is in the unset position, the segments define an outer surface facing the wellbore and at least one end surface extending from the outer surface towards the mandrel. The end surface has a groove that extends around the end surface wherein the groove is not exposed to the wellbore. Additionally, at least when the sealing assembly is in the unset position, the retaining assembly further comprises a band positioned in the groove and suitable for holding the plurality of segments in place about the mandrel.
In another embodiment of the invention there is provided a retaining assembly for limiting the extrusion of a sealing assembly disposed about a mandrel. The sealing assembly is movable from an unset position to a set position in a wellbore, and the sealing assembly seals the wellbore when moved to the set position. The retaining assembly has a plurality of segments with each segment adjacent to at least one other segment. When the sealing assembly is in the unset position the segments define: an inner surface for encircling the mandrel; an outer surface; a first end surface for engaging an end of the sealing assembly and wherein the first end surface extends from the inner surface to the outer surface; and a second end surface opposing the first end surface and extending from the inner surface to the outer surface. Additionally, a first groove extends around the first end surface and a second groove extends around the second end surface. The first and second grooves are spaced from said outer surface. When in place about the mandrel and when the sealing assembly is in the unset position the retaining assembly further has a first band positioned in the first groove and a second band positioned in the second groove. The first band and second band are suitable for holding the plurality of segments in place about the mandrel while the sealing assembly is in the unset position.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a cross-sectional side view of a downhole apparatus having retaining assemblies embodying the present invention.
FIG. 2A is a cross-sectional side view of a sealing assembly and retaining assemblies of the embodiment of FIG. 1 . of the present invention.
FIG. 2B is a cross-sectional side view of a sealing assembly and retaining assemblies of another embodiment of the present invention.
FIG. 3 is a cross-sectional side view of the downhole apparatus of the embodiment of FIG. 1 in a set position.
FIG. 4 is a front view of a retaining assembly of the present invention.
FIG. 5 is a perspective view of a single retaining assembly segment.
FIG. 6 is a perspective view of the retaining assembly of the present invention.
FIG. 7 is a perspective view of the retaining assembly of the present invention as viewed from the opposite side as the view of FIG. 6 .
FIG. 8 is a cross-sectional side view of a prior art packer element and retaining assembly,
DETAILED DESCRIPTION
Referring now to FIGS. 1 , 2 and 3 , downhole tool, or downhole apparatus 10 is shown in an unset position 11 ( FIGS. 1 and 2 ) or a set position 13 ( FIG. 3 ) in a well 15 having a wellbore 20 . The wellbore 20 can be either a cased completion with a casing 22 cemented therein as shown in FIG. 1 or an openhole completion. Generally, as used here in the term “wellbore” will refer to either a cased completion or an openhole completion. Downhole apparatus 10 is shown in set position 13 in FIG. 3 . Casing 22 has an inner surface 24 . An annulus 26 is defined by casing 22 and downhole tool 10 . Downhole tool 10 has a mandrel 28 , and may be referred to as a bridge plug due to the downhole tool 10 having a plug 30 being pinned within mandrel 28 by radially oriented pins 32 . Plug 30 has a seal means 34 located between plug 30 and the internal diameter of mandrel 28 to prevent fluid flow therebetween. The overall downhole tool 10 structure, however, is adaptable to tools referred to as packers, and frac plugs which typically have at least one means for allowing fluid communication through the tool. Packers may therefore allow for the controlling of fluid passage through the tool by way of one or more valve mechanisms which may be integral to the packer body or which may be externally attached to the packer body. Frac plugs control fluid passage through the use of a frac ball. Such valve mechanisms are not shown in the drawings of the present document. Packer tools may be deployed in wellbores having casings or other such annular structure or geometry in which the tool may be set.
Mandrel 28 has an outer surface 36 , an inner surface 38 , and a longitudinal central axis, or longitudinal axial centerline 40 . Also, as referred to herein the term “radially” will refer to a radial direction perpendicular to the longitudinal axial centerline. An inner tube 42 is disposed in, and is pinned to, mandrel 28 to help support plug 30 .
Downhole tool 10 , which as illustrated is a packer apparatus, includes the usage of a spacer ring 44 which is preferably secured to mandrel 28 by pins 46 . Spacer ring 44 provides an abutment, which serves to axially retain slip segments 48 which are positioned circumferentially about mandrel 28 . Slip retaining bands 50 serve to radially retain slip segments 48 in an initial circumferential position about mandrel 28 as well as slip wedge 52 . Bands 50 are made of a steel wire, a plastic material, or a composite material having the requisite characteristics of having sufficient strength to hold the slip segments 48 in place prior to actually setting the downhole tool 10 and to be easily drillable when the downhole tool 10 is to be removed from the wellbore 20 . Preferably, bands 50 are inexpensive and easily installed about slip segments 48 . Slip wedge 52 is initially positioned in a slidable relationship to, and partially underneath, slip segments 48 as shown in FIG. 1 . Slip wedge 52 is shown pinned into place by pins 54 . Designs of slip segments 48 and co-acting slip wedges 52 are described in U.S. Pat. No. 5,540,279, which is incorporated herein by reference.
Located below slip wedge 52 is a sealing assembly 56 , which includes at least one sealing element, and as shown in FIG. 1 includes three expandable sealing elements 58 positioned about mandrel 28 . In packer type tools such sealing elements are often referred to as packer elements. Sealing assembly 56 has upper end 60 and lower end 62 . Sealing assembly 56 has unset and set positions 57 ( FIG. 1) and 59 ( FIG. 3 ) corresponding to the unset and set positions 11 and 13 , respectively, of downhole tool 10 . The sealing assembly 56 is radially expandable from the unset position 57 to a set position 59 in response to the application of axial force on the sealing assembly 56 . In the set position 59 , the sealing assembly 56 engages the casing 22 to create a seal to prevent flow through annulus 26 .
The present invention has retaining assemblies 66 disposed at the upper and lower ends 60 and 62 of sealing assembly 56 to axially retain the sealing assembly 56 . Retaining assemblies 66 (also referred to as retaining shoes or extrusion limiters) may be referred to as an upper retaining assembly 68 and a lower retaining assembly 70 . A slip wedge 72 is disposed on mandrel 28 below lower retaining assembly 70 and is pinned with a pin 74 . Located below slip wedge 72 are slip segments 76 . Slip wedge 72 and slip segments 76 are like slip wedge 52 and slip segments 48 . At the lowermost portion of downhole tool 10 is an angled portion, referred to as mule shoe 78 , secured to mandrel 28 by pin 79 . The lowermost portion of downhole tool 10 need not be mule shoe 78 but can be any type of section which will serve to terminate the structure of the downhole tool 10 or serve to connect the downhole tool 10 with other tools, a valve or tubing, etc. It will be appreciated by those in the art that pins 32 , 46 , 54 , 74 , and 79 , if used at all, are preselected to have shear strengths that allow for the downhole tool 10 to be set and deployed and to withstand the forces expected to be encountered in the wellbore 20 during the operation of the downhole tool 10 .
FIG. 8 shows a prior art arrangement of a retaining assemblies 150 , which may referred to as retaining shoes or extrusion limiters. Upper and lower retaining assembly 152 and 154 are essentially identical. Therefore, the same designating numerals will be used to further identify features on each of retaining shoes 152 and 154 , which are referred to collectively herein as retaining assemblies 150 . Retaining assemblies 150 comprise an inner shoe, or inner retainer 156 and an outer shoe, or outer retainer 158 Inner and outer shoes 156 and 158 are held in place by retaining bands 160 , which are received in a groove 162 . Retaining bands 160 are exposed so that they can undergo inadvertent contact with a wellbore, a casing within a wellbore, or other object.
Referring now to FIGS. 2 A and 4 - 7 , the retaining assemblies 66 (also called retaining shoes or extrusion limiters) of the present invention will be described. Upper and lower retaining assemblies 68 and 70 are essentially identical. Therefore, the same designating numerals will be used to further identify features on each of retaining assemblies 68 and 70 , which are referred to collectively herein as retaining assemblies 66 . Retaining assemblies 66 are preferably comprised of a plurality of retainer segments, or shoe segments, 80 to form retaining assemblies 66 that encircles mandrel 28 . Retainer segments 80 can be made form any suitable material that will withstand the downhole use and yet can be readily cut or ground up by drilling with a drill bit. Generally, non-metallic engineering grade plastics can be used for the retaining materials, such as composite materials or structural phenolic materials. A suitable phenolic materials are available from General Plastics & Rubber Company, Inc., 5727 Ledbetter, Houston, Tex. 77087-4095. Alternatively, structural phenolics available from commercial suppliers may be used. A suitable composite materials are available from General Plastics & Rubber Company, Inc., 5727 Ledbetter, Houston, Tex. 77087-4095. Particularly suitable materials for at least a portion retaining assemblies 66 includes direction specific composite material available from General Plastics & Rubber Company, Inc.
Retaining assemblies 66 have an outer surface 82 . Retaining assemblies 66 also have an inner surface 84 composed of inner surface 86 , first end surface 88 and second end surface 90 . When the downhole tool is in the unset position 11 , retaining segments 80 define outer surface 82 and inner surface 84 . Generally outer surface 82 will be substantially cylindrical and face the wellbore 20 . In the set position 13 , the arc surfaces 83 of retaining segments 66 making up outer surface 82 engage the wellbore. Generally inner surface 86 will be a substantially cylindrical inner surface, which encircles the mandrel. Timer surface 86 is defined by arc surfaces 87 of retaining segments 66 . Arc surfaces 87 engage mandrel 28 in an initial or running position of the downhole tool 10 . First end surface 88 extends from the outer surface 82 to inner circle 86 . Additionally, first end surface 88 extends in a generally circumferential direction but is preferably not parallel to the radial direction. As can best be seen from FIG. 6 , first end surface 88 can have an arcuate shaped cross-section or can be sloped. In the embodiment shown, first end surface 88 is shaped to accommodate the upper and lower ends 60 and 62 of the sealing assembly 56 and, thus, is preferably sloped as well as arcuate to provide a generally truncated conical surface which transitions from having a greater radius proximate outer surface 82 to a smaller radius proximate substantially cylindrical inner surface 86 . Second end surface 90 opposes first end surface 88 and, hence, extends from the outer surface 82 to inner circle 86 . Additionally, second surface 90 extends in a generally circumferential direction. Second end surface 90 may be generally parallel to the radial direction or may be at a slight angle, preferably less than 10° from parallel to the radial direction. However, it is within the scope of the invention for both end surfaces (first end surface 88 and second end surface 90 ) to have other shapes as long as they generally extend circumferentially and from outer surface 82 to inner surface 86 .
As shown in FIG. 2 , upper and lower ends 60 and 62 of sealing assembly 56 reside directly against upper and lower retaining assemblies 68 and 70 . Retaining assemblies 66 are preferably comprised of a plurality of retainer segments 80 that encircles mandrel 28 . Each retainer segment 80 has ends 92 and 94 , which can be flat and convergent with respect to a center reference point, which, if the retainer segments 80 are installed about mandrel 28 , will correspond to the longitudinal central axis 40 of the mandrel 28 as depicted in FIG. 1 . Ends 92 and 94 need not be flat and can be of other topology. In a preferred embodiment end 92 has a shelf 96 and end 94 has a tongue portion 98 , as can be seen in FIGS. 5 and 6 . Tongue portion 98 is adapted to be received onto shelf 96 so that, in the unset position 11 , retainer segments overlap and form a substantially continuous ring. Further tongue portion 98 and shelf 96 are adapted so that, when retaining assemblies 66 are expanded in the set position 13 , the retaining segments still overlap and extrusion of the sealing elements 58 through the gaps 118 between retaining segments is blocked by the tongue and shelf arrangement.
FIG. 4-7 illustrate retaining assemblies 66 being made of a total of eight retainer segments 80 to provide a 360 degrees annulus encircling structure to provide a maximum amount of end support for sealing elements 58 to be retained in the axial direction. A lesser or greater amount of retainer segments 80 can be used depending on the nominal diameters of the mandrel 28 , the sealing elements 58 , and the wellbore 20 or casing 22 in which the downhole tool 10 is to be deployed. Inner diameter 122 generally approaches the inner diameter of the sealing assembly 56 . As is apparent from the drawings, outer surface 82 faces outwardly away from the downhole tool 10 . The slope of first end surface 88 is preferably approximately 45 degrees as shown in FIG. 2 . However, the exact slope will be determined by the exterior configuration of the ends of the sealing elements 58 that are to be positioned and eventually placed in contact with retaining assemblies 66 and first end surface 88 . Inner surface 86 of retaining assembly 66 can be slightly sloped, approximately 5 degrees if desired, but it is best determined by the surface of the downhole tool 10 which it eventually abuts against when downhole apparatus 10 is centered in the wellbore 20 .
Each retainer segment 80 can have a lug (protruding member) 100 extending out from second end 90 . As can be seen from FIGS. 1 and 2 , the lugs 100 of upper retaining assembly 68 contacts or abuts a slip wedge 52 such that an upper gap 110 is created when the downhole tool is in the unset position 11 . As can be seen in FIG. 3 , when the downhole tool is moved to the set position, tipper retaining assembly 68 expands allowing slip wedge 52 to slide under the lugs 100 and fill gap 110 such that the end of the slip wedge that abutted the lugs is now between the lugs and the mandrel. Similarly, the lugs 100 of lower retaining assembly 70 contacts slip wedge 72 such that a lower gap 112 is created when the downhole tool is in the unset position. Also, when the downhole tool is moved to the set position, upper retaining assembly 70 expands allowing slip wedge 72 to slide under the lugs 100 and fill gap 112 .
An important aspect of the current invention is groove 114 and 116 . Groove 114 extends circumferentially around the first end surface 88 . Groove 116 extends circumferentially around the second end surface 90 . Retaining band 115 is positioned in groove 114 and retaining band 117 is positioned groove 116 . Retaining bands 115 and 116 are received in grooves 114 and 116 to initially hold the retainer segments 80 in place prior to setting the downhole tool 10 into the set position 13 . It is a preferred embodiment that the grooves 114 and 116 and retaining bands 115 and 117 be located on inner surface 84 instead of outer surface 82 . More preferably the grooves 114 and 116 and retaining bands 115 and 117 should be located on first end surface 88 and second end surface 90 . The grooves 114 and 116 should be spaced from outer surface 82 , i.e., not exposed to the wellbore 20 or not facing the wellbore 20 . Location of the bands and grooves in these positions prevent contacts that might fracture or release the bands and result in premature expansion of the retainer segments 80 . Retaining bands 115 and 117 may be made of a nonmetallic material, such as composite materials available from General Plastics & Rubber Company, Inc., 5727 Ledbetter, Houston, Tex. 77087-4095. However, bands 114 and 116 may be alternatively made of a metallic material such as ANSI 1018 steel or any other material having sufficient strength to support and retain the retaining assembly 66 in position prior to actually setting the downhole tool 10 . Furthermore, retaining bands 115 and 117 may have either elastic or non-elastic qualities depending on how much radial, and to some extent axial, movement of the retainer segments 80 can be tolerated prior to enduring the deployment of the associated downhole tool 10 into the wellbore 20 .
In unset position 57 , retaining bands 115 and 117 serve to hold retainer segments 80 in place. Prior to the downhole tool 10 being set, retaining assemblies 66 engage mandrel 28 about the upper and lower ends 60 and 62 of the sealing assembly 56 . Lower retaining assembly 70 engages lower end 62 of sealing assembly 56 and upper retaining assembly 68 engages the upper end 60 of sealing assembly 56 in the unset positions 11 and 57 of downhole tool 10 and the sealing assembly 56 , respectively. When the downhole tool 10 has reached the desired location in the wellbore 20 , setting tools as commonly known in the art will move the downhole tool 10 and, thus, the sealing assembly 56 , to their set positions 13 and 59 , respectively, as shown in FIG. 3 .
Gaps 118 have a width 120 that can be essentially zero when the retainer segments 80 are initially installed about mandrel 28 , and before the downhole tool 10 is moved from the unset position 11 to the set position 13 . However, a small gap, for example a gap of 0.06″ may be provided for on initial installation. The width 120 of gap 118 will increase from that which exists on initial installation, as the downhole tool 10 is set.
When the downhole tool 10 is moved to its set position 13 , retaining bands 115 and 117 will break and retaining assembly 66 will move radially outwardly so that arc surfaces 83 of each retainer segment 80 will engage inner surface 24 of casing 22 . The radial movement will cause width 120 of gaps 118 to increase. However, the tongue portion 98 and shelf 96 of retainer segments 80 will still overlap and, thus, extrusion of sealing elements 58 through gaps 118 and past retaining assembly 66 will be prevented. Additionally, the slip wedges 52 and 72 will move under lugs 100 , as described above. Accordingly, slip wedges 52 and 72 will prevent extrusion of sealing elements 58 between retaining assembly 66 and mandrel 28 as illustrated in FIG. 3 .
As can be understood from the foregoing description, the extrusion of sealing elements 58 is essentially eliminated, since arc surface 83 engage the wellbore 20 and prevent extrusion on the wellbore side of the downhole tool. Additionally, any material extruded through gaps 118 will be blocked by the tongue and shelf arrangement of the retainer segments, extrusion between retainer segments 80 and mandrel 28 is blocked by the slip wedges 52 and 72 . Retaining assemblies 66 are thus expandable retaining shoes that will prevent or at least limit the extrusion of the sealing elements 58 and be less subject to premature expansion. Retaining assembly 66 may also be referred to as an expandable retainer. The arrangement is particularly useful in high pressure, high temperature wells, since there is no extrusion path available. It should be understood, however, that the disclosed retaining assembly 66 may be used in connection with packer-type tools of lesser or greater diameters, differential pressure ratings, and operating temperature ratings than those set forth herein.
Turning now to FIG. 2B an alternative embodiment of the invention is shown. In FIG. 2B similar parts to those in FIG. 2A have been given the same reference number. In the embodiment of FIG. 2B there is upper retaining assembly 132 and lower retaining assembly 134 . Upper and lower retaining assemblies 134 are essentially identical. Therefore the same designating numerals will be used to further identify features on each of retaining assemblies 132 and 134 , which are referred to collectively herein as retaining assemblies 130 . Retaining assemblies 130 comprising an inner ring 136 and an outer ring 142 . Inner ring 136 can have an arcuate or an angular cross section and mates with outer ring 142 , such that radial portion 138 is between outer ring 142 and either the upper or lower end of the sealing assembly 60 or 62 and such that the longitudinal or axial portion 140 of inner ring 136 is between mandrel 28 and outer ring 142 . Additionally, inner ring 136 can be comprised of a plurality of segments with each segment adjacent to at least one other segment. Outer ring 142 is essentially identical to retaining assemblies 66 , except that it has a larger inner diameter 122 to accommodate inner ring 136 .
Although the disclosed invention has been shown and described in detail with respect to a preferred embodiment, it will be understood by those skilled in the art that various changes in the form and detailed area may be made without departing from the spirit and scope of this invention as claimed. Thus, the present invention is well adapted to carry out the object and advantages mentioned as well as those which are inherent therein. While numerous changes may be made by those skilled in the art, such changes are encompassed within the spirit of this invention as defined by the appended claims. | An improved downhole tool apparatus for limiting the extrusion of a sealing elements in downhole tools that use segmented retaining assemblies, retaining shoes or retaining limiters. The apparatus provides for locating the retaining bands for the retaining assemblies in a groove on the inner surface of the retaining assembly so that the bands are protected from breaking prematurely by inadvertently contacting the wellbore, casing within a wellbore, or other object. | 4 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is based upon and claims the benefit of priority from French Patent Application No. 1258429, filed Sep. 10, 2012, the entire content of which is incorporated herein by reference.
BACKGROUND
[0002] The present invention relates to the general field of producing fibrous sheets obtained by spreading several cables of fibers or yarns.
[0003] One favored, but nonexclusive field of application of the invention is that of the production of three-dimensional fibrous preforms intended for the manufacture of annular parts made from a carbon-carbon (C-C) composite material, in particular the manufacture of brake disks.
[0004] Brake disks made from composite material, in particular a composite material reinforced with carbon fibers and a carbon matrix, are well known. Their manufacture comprises the production of an annular fibrous preform and the densification thereof by a matrix.
[0005] One known method for producing an annular fibrous preform consists of producing annular fibrous sheets (i.e., a so-called transverse sheet and a so-called circumferential sheet) by spreading and juxtaposition of several cables of carbon fibers or carbon yarns. The transverse and circumferential sheets are then bonded to each other by needling and are rotated. A thick annular fibrous structure is obtained by bonding several layers to each other by circular needling.
[0006] This method, one example embodiment of which is described in document WO 2007/048946, thus makes it possible to obtain an annular fibrous preform directly from cables of carbon fibers or carbon yarns with practically no wastage.
[0007] With such a method, the cables forming the transverse sheet are more precisely laid alternating in one direction and the other between the outer and inner coaxial rings of an installation. Inevitably, such a laying causes tightening of the carbon fibers or yarns toward the inner ring (relative to the outer ring).
[0008] Consequently, to obtain an annular fibrous sheet that is completely homogenous over its entire width, it is necessary to compensate the increase in the surface density of the transverse sheet at the inner ring due to this tightening through a corresponding decrease in the surface density of the circumferential sheet in that location.
[0009] To give the circumferential sheet a decreasing surface density between the outer ring and the inner ring of the installation, it is possible to form said sheet with cables having a same width, but having decreasing weights between the rings. However, this solution is relatively impractical to implement and requires the use of cables with different weights.
[0010] Another solution consists of further spreading the cable(s) in question before they are laid. However, the known spreading solutions have a certain number of drawbacks. In particular, a spreading device by blowing air does not make it possible to freeze the width of the cable and thus prevent it from returning to its initial appearance before it was placed between the rings of the installation. It is also important for the spreading of the cable to be done while preserving the homogeneity of fibers within the cable. Lastly, it must be possible to spread the cable without creating tension in the cable.
SUMMARY
[0011] There is therefore a need to be able to have a device for spreading a cable of carbon fibers or carbon yarns that meets all of these constraints.
[0012] According to an aspect of the invention, this goal is achieved by a device for spreading a cable of carbon fibers or carbon yarns, comprising
[0013] a disk mounted on a rotary shaft and provided with at least one comb adapted to comb a cable of carbon fibers or carbon yarns in a direction substantially parallel to the longitudinal direction of the fibers or yarns of the cable, said comb including a plurality of teeth protruding radially toward the outside of the disk, and means for rotating the disk around its rotary axis.
[0014] With such a device, by causing the cable of carbon fibers or carbon yarns to pass through the teeth of the comb (or by making it flush with the teeth of the comb), it is possible to spread the fibers or yarns so as to widen the cable upon leaving the device. In fact, it has been observed that the teeth of the comb that penetrate the cable (or that are flush with it) to comb it in a direction substantially parallel to the longitudinal direction of the fibers or yarns forming the cable make it possible to spread the cable in the direction of its width. Furthermore, it has been observed that after combing, the cable remains at its width. It is in particular not necessary to use thermo-bonding fibers to ensure that the width of the cable is maintained. Furthermore, by causing the cable to pass in the same direction of movement as the direction of rotation of the disk of the device, it is possible to achieve widening of the cable without creating tension therein at the outlet of the device. Lastly, this device is easy to implement, does not create noise disturbance, and can easily be integrated into an installation for manufacturing an annular fibrous sheet.
[0015] In an embodiment, the device further comprises means for adjusting the radial position of the comb on the disk. For example, a radial position adjusting device may be used. Thus, the comb may be mounted on the disk in a radial groove and capable of sliding inside the latter so as to allow adjustment of the radial position of said comb on the disk.
[0016] Also in an embodiment, the device further comprises means for adjusting the orientation of the teeth of the comb. For example, an orientation adjusting device may be used. Thus, the comb may be mounted on the disk by means of a pivoting link so as to make it possible to adjust the orientation of the teeth of said comb.
[0017] An aspect of the invention also relates to a method for spreading a cable of carbon fibers or carbon yarns, consisting of at least making the teeth of the comb of the device as previously defined flush with the cable in a direction substantially parallel to the longitudinal direction of the fibers or yarns of said cable.
[0018] The cable of carbon fibers or carbon yarns may move relative to the device in a direction substantially tangential to the disk.
[0019] Furthermore, the cable of carbon fibers or carbon yarns may move relative to the device in the same direction as the direction of rotation of said disk. It is thus possible not to generate tension in the cable.
[0020] The teeth of the combs of the device may penetrate the cable without passing through it. In this way, it is easy to preserve homogeneity of fibers in the cable after it has passed through the teeth of the combs of the device.
[0021] Another aspect of the invention also relates to the use of such a method to produce a fibrous sheet by spreading and juxtaposing several cables of carbon fibers or carbon yarns.
BRIEF DESCRIPTION OF THE DRAWINGS
[0022] Other features and benefits of the present invention will emerge from the description provided below, in reference to the appended drawings, which illustrate one non-limiting example embodiment thereof. In the figures:
[0023] FIG. 1 is a perspective view of a device for spreading a cable of carbon fibers or carbon yarns according to the invention;
[0024] FIGS. 2 and 3 diagrammatically show the operation of the device of FIG. 1 .
DETAILED DESCRIPTION
[0025] An embodiment of the invention is particularly applicable to installations for manufacturing an annular fibrous preform intended to produce annular parts made from a carbon-carbon (C-C) composite material, in particular for the manufacture of brake disks.
[0026] An installation for manufacturing an annular fibrous preform is described in patent application WO 2007/048946, the content of which is integrated by reference and will therefore not be outlined here.
[0027] In substance, such an installation comprises a device for bringing in a first fibrous sheet and laying the latter on an annular support alternating in one direction and then the other between the outer and inner coaxial circular rings situated on either side of the annular support to form a first annular sheet, or transverse sheet.
[0028] Such an installation also comprises a device for bringing in a second fibrous sheet on the annular support and laying the latter in the circumferential direction between the outer and inner rings to form a second annular sheet, or circumferential sheet. A device is provided to rotate the transverse and circumferential sheets around the axis of the rings.
[0029] With this type of installation, it is necessary to give the circumferential sheet a decreasing surface density between the outer ring and the inner ring to balance the increasing surface density of the transverse sheet and thus to obtain an assembly having a substantially uniform surface density over its entire width.
[0030] The device according to an embodiment of the present invention allows performing such a function by performing spreading (or widening) of one or more fibers or yarns cables (or tows)—here carbon cables—used to produce the circumferential sheet.
[0031] It will be appreciated that the spreading device according to an embodiment of the present invention more generally applies to any installation in which one wishes to obtain widening of a fibers or yarns cable, this widening having to remain frozen after the cable has passed through the device.
[0032] The spreading device 10 shown in FIGS. 1 to 3 may thus adapt to an installation for manufacturing an annular fibrous preform like that described in patent application WO 2007/048946. In particular, this spreading device may be mounted just upstream from the device for bringing in the second fibrous sheet on the annular support of the installation.
[0033] In this type of installation, the cable of carbon fibers or carbon yarns intended to form the circumferential sheet of the annular fibrous preform generally pass through eyelet plates 12 . At the outlet of these eyelets, each cable 100 passes over a guide bar 14 before being conveyed toward the spreading device 10 according to the invention.
[0034] The cables of carbon fibers or carbon yarns 100 used may be formed from 50,000 filaments (50 K) or 24,000 filaments (24 K), having respective masses of 3.85 kTex and 1.6 kTex.
[0035] The spreading device 10 according to an embodiment of the invention comprises a disk 16 that is mounted on a support (not shown) rotatably relative to it is axis of revolution 18 . The rotation of the disk around its axis of revolution is ensured by an electric motor 20 also mounted on the support of the spreading device (or by any other means or devices).
[0036] The disk 16 is provided with at least one comb 22 (there are 8 in the example illustrated in FIGS. 1 to 3 ) that is adapted to comb one or more cables of carbon fibers or carbon yarns in a direction substantially parallel to the longitudinal direction of the fibers or yarns of the cable. To that end, the bars 14 are positioned relative to the disk 16 so as to ensure guiding of one or more cables to be spread toward the disk in a direction substantially tangential thereto.
[0037] To ensure such combing, each comb 22 comprises multiple teeth 24 ( FIG. 3 ) protruding radially outward from the disk. Owing to the guiding of the cable(s) to be spread by the bars 14 of the spreading device, at least some of the teeth 24 of the combs at least partially penetrate the corresponding cable(s) to spread them, as will be described later relative to FIGS. 2 and 3 .
[0038] It should be noted that the combs 22 mounted on the disk of the device do not necessarily have the same characteristics. For example, it is possible to have combs whereof the geometry and nature of the teeth (length, diameter, profile, geometry of the tip, material, etc.) differ. These characteristics are parameters that influence the degree of widening of the cable.
[0039] According to one beneficial arrangement shown more specifically in FIG. 1 , each comb 22 is mounted in a radial groove 26 formed in the disk 16 and can slide inside the latter so as to make it possible to adjust the radial position of said comb on the disk. Notches 28 formed in the radial grooves 26 ensure that the combs are kept in position. It is thus possible to adjust the position of the columns as a function of the cables used.
[0040] According to another beneficial arrangement, each comb 22 is mounted on the disk 16 by means of a pivot link (not shown in the figures) so as to make it possible to adjust the orientation of the teeth of said comb (arrows F in FIG. 1 ). In particular, it is thus possible to adjust the angle between the cable to be combed and the teeth of the comb.
[0041] FIGS. 2 and 3 diagrammatically show one example of embodiment of such a spreading device.
[0042] A cable 100 of carbon fibers or carbon yarns supplies the spreading device by traveling through the eyelet plates 12 thereof. The cable 100 reaches the bars 14 , which guide it toward the disk 16 of the spreading device. More specifically, as shown in FIG. 2 , the cable 100 is guided to progress tangentially relative to the disk 16 .
[0043] The disk 16 of the spreading device is rotated around its axis of revolution 18 such that at least one of its combs 22 combs the cable in a direction substantially parallel to the longitudinal direction of the fibers or yarns forming said cable. During this movement, the teeth 24 of the combs that comb the cable during the rotation of the disk penetrate at least partially the fibers or yarns of the cable.
[0044] It has been observed that simple combing (that does or does not go through the cable) of the fibers or yarns of the cable makes it possible to obtain spreading thereof (the width L 1 of the cable 100 at the outlet of the spreading device is greater than its width L 2 at the inlet— FIG. 3 ). Furthermore, the spreading is obtained while preserving the homogeneity of the fibers in the direction of the width of the cable after the passage thereof in the teeth of the comb.
[0045] In particular, the final width of the cable may be controlled as follows. Once an optimal configuration has been defined (in particular in terms of number of combs, number and geometry of teeth of the combs, radial position of the combs, angle between the teeth of the comb and the cable etc.), the final length of the cable may be regulated simply by adjusting the speed of rotation of the disk. Furthermore, regarding overlap of the combing, at a certain speed of rotation of the disk, the cable may be combed several times in the same location, which will make it possible to obtain a more significant final widening.
[0046] A widening test was done on a cable taking a cable of carbon fibers or yarns made up of 50,000 filaments and having an initial width of approximately 20 to 25 mm. The device used during this test comprised 6 combs each having a width of 60 mm and being provided with teeth with sharp ends (with a gap between two adjacent teeth of approximately 2 mm). The columns were mounted on a disk having a diameter of 200 mm and driven at a speed of rotation of 140 revolutions per minute in the direction of movement of the cable.
[0047] This test made it possible to obtain, at the outlet of the device, a cable width of approximately 50 mm, compared to the initial width of 20 to 25 mm. It is thus easy to double the width of the cable.
[0048] It was also observed that the spreading of the cable remained frozen after it passed through the teeth of the comb, i.e., it did not return it to its initial width after being combed.
[0049] Various parameters influence the spreading of the cable that passes through the teeth of the comb. Thus, if one wishes for the combing not to create tension in the cable, it is desirable for the movement direction S 1 of the cable to be identical to the direction of rotation S 2 of the disk 16 of the spreading device. Conversely, if one wishes to generate tension in the cable, it is desirable for these directions of movement to be contrary.
[0050] Likewise, the number of combs that penetrate the cable, the length of their travel in the cable, the number of combing cycles, etc. are all parameters that have a direct impact on the spreading of the cable. | A device for spreading a cable of carbon fibers or carbon yarns, includes a disk mounted on a rotary shaft and provided with at least one comb adapted to comb a cable of carbon fibers or carbon yarns in a direction substantially parallel to the longitudinal direction of the fibers or yarns of the cable. The comb includes a plurality of teeth protruding radially toward the outside of the disk, and a device for rotating the disk around its rotary axis. Furthermore, a method for spreading a cable of carbon fibers or carbon yarns, includes at least making the teeth of the comb of the device flush with the cable in a direction substantially parallel to the longitudinal direction of the fibers or yarns of the cable. | 3 |
[0001] This invention is a bicycle-mounted exerciser that provides an adjustable, variable resistance to a bicycle wheel, thereby requiring a bicycle rider to exert more or less energy to pedal the bicycle. By working against a resistance, a bicycle rider can get exercise and training for leg strength and overall endurance as part of a physical training program while riding a bicycle. The exerciser device is mounted to the post supporting the bicycle seat, and is adjustable to enable a friction wheel to be pressed downward against the bicycle's driving wheel with sufficient force to substantially eliminate slippage between the bicycle's driving wheel and the exerciser's friction wheel. If desired, the exercise device may be raised above the bicycle wheel to allow the driving wheel to turn without being in contact with the exercise device.
BACKGROUND OF THE INVENTION
[0002] Many kinds of exercise devices have been used on bicycles and other pedal-operated equipment to artificially increase resistance to pedaling whereby a rider will have to exert greater force upon the bicycle pedals in order to turn them. Some such devices are found in so-called “stationary” bicycles which are designed to be used in a gymnasium or other enclosed area, and which serve the sole purpose of providing resistance to a pedaling movement. Other exercise devices have been designed as stationary platforms for standard bicycles that can be placed upon the platform to provide resistance to pedaling. Because stationary bikes and standard bicycles placed upon a stationary platform are not mobile, and are used within a controlled physical space, the friction generating mechanisms can be as large, heavy, or intricate as may be required to provide the necessary resistance to motion. However, bicycles are primarily used for traversing terrain, and many riders enjoy the freedom of being able to cover distances on a bicycle while also obtaining exercise. For such riders, a suitable exercise device must be mounted upon the bicycle and must be operable by a rider under varying conditions of speed and terrain. For a bicycle-mounted exercise device, factors such as weight, simplicity of operation, ruggedness, and efficiency in dissipating heat that is generated through the friction of restraining the circular motion of the bicycle driving wheel take on added importance.
SUMMARY OF THE INVENTION
[0003] The exercise device of this invention is a seat-post mounted frame supporting a friction wheel and a braking wheel that are rigidly joined with a common axle. The friction wheel is held in non-slipping contact with a bicycle wheel while the braking wheel is subjected to a braking force applied through an adjustable brake pad. Although it is preferred that the friction be in non-slipping contact with the rear (driving) wheel of a bicycle, the device will provide adequate resistance to pedaling when placed in non-slipping contact with a non-driving bicycle wheel. The rotation of the exerciser's braking wheel is retarded by a brake pad mounted within the braking wheel. The brake pad has a linkage to a hand lever operated by the rider for adjusting the amount of resistance to rotation being provided at any given time. A turn screw on the exercise device is used to adjust the downward force of the friction wheel against a wheel of the bicycle to ensure sufficient pressure to avoid slippage during operation of the exercise device. When the exercise device is not being used, the turn screw can be adjusted to hold it out of the way, above the driving wheel.
BRIEF DESCRIPTION OF THE DRAWINGS
[0004] FIG. 1 is a right elevational view showing the exercising device in relation to a bicycle rear wheel and seat mounting post.
[0005] FIG. 2 is a perspective view of the exercise device of this invention.
[0006] FIG. 3 is a detailed right elevational view depicting the friction wheel of the exercise device being held out of contact with a bicycle tire.
[0007] FIG. 4 is a detailed right elevational view showing the friction wheel of the exercise device being held against a bicycle tire.
[0008] FIG. 5 is a left elevational view showing the braking wheel with the spring linkage holding the brake pad away from contact with the braking wheel.
[0009] FIG. 6 is a left elevational view showing the brake pad being pressed into operating engagement with the braking wheel.
[0010] FIG. 7 is a plan view of the exercise device with the mounting clamp in an open position.
[0011] FIG. 8 is a plan view of the exercise device with the mounting clamp closed and tightened.
[0012] FIG. 9 is a detailed perspective view of the friction wheel and braking wheel of the invention.
[0013] FIG. 10 is a cutaway front view of the braking wheel taken along plane A-A′.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0014] As shown in FIG. 1 , the exercise device of this invention 10 is mounted on a bicycle by being attached to the bicycle seat post where it can be positioned in relation to the rear wheel of a bicycle. An adjustment turn screw 40 may be tightened to press the device against the bicycle wheel, or may be released to relieve the downward pressure and permit the device to be raised above the bicycle wheel.
[0015] FIG. 2 shows the exercise device in perspective view. A friction wheel 20 and a braking wheel 30 are maintained in rigid co-axial relationship upon a single axle 50 . The friction wheel is in contact with the bicycle tire during operation. Although the diameters of the friction wheel 20 and the braking wheel 30 are shown as being substantially equal in FIG. 2 , this is not a requirement for acceptable operation of the exercise device, and the braking and friction wheels of the device may be of different sizes in order to achieve a desired combination of rotational speed and braking forces.
[0016] The exercise device has three framing pieces that may be adjusted to properly position the friction and braking wheels above the rear wheel of a bicycle. An upper frame 90 is rigidly attached to an adjustable clamp 60 that secures the device to the post of a bicycle seat. Middle frame 100 is securely fastened to upper frame 90 . Middle frame 90 also includes an adjustment bracket 70 through which is threaded a turn screw 40 that is used to make fine adjustments to the positioning of the friction wheel 20 upon a bicycle tire. Lower frame 110 is pivotably joined to middle frame 100 at pin 180 , and has a pressure plate 160 rigidly attached to the lower frame below tuna screw 40 . Brake piston 120 and brake cylinder 190 are visible adjacent to lower frame 110 .
[0017] As seen in FIG. 2 , the upper frame 90 , middle frame 100 , and lower frame 110 have large open cavities which result in an overall weight reduction for the device. Strong, lightweight materials are desirable, as they provide sufficient retarding forces when the device is applying friction, yet do not otherwise hinder operation of the bicycle when the device is raised to eliminate additional friction that is supplied by the exercise device.
[0018] As shown in FIG. 5 , lower frame 110 securely supports braking wheel 30 and friction wheel 20 while permitting them to rotate together, and also supports the braking assembly comprising brake piston 120 , brake spring 130 , brake cable 140 , brake cylinder 190 , and brake pad 150 . In FIG. 5 , brake pad 150 is being held away from contact with the inner portion of braking wheel 30 by brake spring 130 , allowing braking wheel 30 to rotate freely. Also, FIG. 5 shows the braking wheel being a spoked wheel, rather than a solid disc, thereby reducing the mass of the wheel and the overall weight of the exerciser.
[0019] FIG. 6 shows brake pad 150 being drawn against the inner circumference of braking wheel 30 when brake cable 140 is tightened. A conventional hand lever or turning knob (not shown) can be mounted on the bicycle handle bars or some other convenient location, and may be adjustable to increase or decrease resistance to the rotation of braking wheel 30 and, through axle 50 , with friction wheel 20 . As brake pressure is applied, resistance causes the braking wheel 30 to transmit a retarding force to the friction wheel 20 through common axle 50 , thereby placing additional resistance upon the friction wheel 20 and the bicycle tire, requiring the rider to exert more effort while riding and obtain the desired exercise and training.
[0020] A turn screw 40 is threaded into adjustment bracket 70 which is rigidly attached to middle frame 100 . Turn screw 40 protrudes downwardly to contact pressure plate 160 which is rigidly attached to lower frame 110 . When tightened downwardly, turn screw 40 presses against pressure plate 160 , causing lower frame 110 to pivot about pin 180 toward the bicycle tire, bringing friction wheel 20 into contact with the tire, as is depicted in FIG. 4 . Pin 180 is a bolt having a locking nut that may be tightened or loosened, as circumstances require, to allow lower frame 110 to be pivoted about rotating pin 180 with a slight amount of force. FIG. 3 also shows a raising spring 170 (in phantom) behind middle frame 100 . Raising spring 170 places upward pressure on lower frame 110 and holds pressure plate 160 against turn screw 40 . When the friction wheel 20 is to be raised above the bicycle tire, turn screw 40 is backed partially out of adjustment bracket 70 , allowing raising spring 170 to force lower frame 110 upwards. Friction wheel 20 will then be raised above the bicycle tire. FIGS. 3 and 4 depict the friction wheel as having spokes, although the friction wheel may be a solid disc, depending upon engineering preferences.
[0021] When the bicycle to which the exercise device is mounted is being operated over open terrain, turn screw 40 is subject to vibration that may cause unwanted tightening into adjustment plate 70 , changing the setting previously applied by the rider, and increasing the pressure holding friction wheel 20 against the bicycle tire. To prevent such inadvertent tightening of the turn screw, a turn screw spring 80 may be coiled about the shaft of the turn screw, and will operate to counteract the force of gravity that would otherwise cause turn screw 40 to tighten.
[0022] The exercise device of this invention is portable from bicycle to bicycle, and has sufficient adjustment pins, levers, and screws to make it suitable for nearly all conventional bicycles. As is shown in FIGS. 7 and 8 , a quick-release clamp 40 is used to secure the exercise device to the post of a bicycle seat. A cambered lever 200 is pivotally connected to a shaft 220 which is itself pivotally attached to one of two opposing clamp arms 210 . Each of the clamp arms pivots between an open and closed position, depicted respectively in FIGS. 7 and 8 . If desired, shaft 220 can be threaded to permit the distance between clamp arm 220 and cambered lever 200 to be lengthened or shortened to accommodate larger or smaller diameter bicycle seat posts. When clamp 40 is closed, as shown in FIG. 8 , cambered lever 200 will pivot to an over-center position in which the clamp will remain closed -until manually released.
[0023] A detailed depiction of the braking wheel 30 and the friction wheel 20 is given in FIG. 9 . Friction wheel 20 may have an abraded or other non-slip circumferential surface to prevent slippage between friction wheel 20 and a bicycle tire. Friction wheel 30 has a cylindrical configuration extending around the circumference of the wheel. Brake pad 150 fits within the circumference defined by the inner cylindrical surface and, when activated through brake piston 120 , will exert a frictional force against the inner portion of the cylindrical surface to retard rotation of the braking wheel. FIG. 10 shows a cutaway front view of the braking wheel taken along line A-A′. In one embodiment, the cylindrical surface of braking wheel 30 extends beyond the disc of the wheel on both sides of the disc to create spaces for brake pads 150 on both sides of the disc. This embodiment may be used where strong braking forces are desired, or to maintain symmetrical braking forces upon braking wheel 30 . Where dual brake pads are used, brake piston 120 will attach to both brake pads using a “U” shaped harness, enabling both brake pads 150 to apply force to braking wheel 30 with a single movement of the brake cable 140 .
[0024] It will be understood that the embodiments disclosed herein are exemplary, and that persons of ordinary skill may conceive additional embodiments not explicitly described herein, but which fall within the disclosure and scope of the invention. The invention is therefore limited only by the claims appended hereto. | A bicycle trainer is a bicycle-mounted apparatus used to produce friction to resist the turning of a wheel of a bicycle, thereby requiring the rider to exert more energy than would otherwise be necessary. The bicycle trainer is adjustable by the rider while riding, and can simulate hill or mountain climbing at any positive grade. | 0 |
REFERENCE TO RELATED APPLICATIONS
This application claims the benefit under 35 U.S.C. §119(e) of prior U.S. Provisional Patent Application Ser. No. 61/820,366 filed May 7, 2013.
TECHNICAL FIELD
The present invention relates generally to articles used for bedding, and in particular, to bed sheets, blankets, quilts, duvets or duvet covers. More specifically, this invention relates to an improved bedding product that is placed on a mattress and is configured to fit the contours of the mattress tightly. Although the invention will be described in relation to a fitted bed sheet, it is to be understood that it could be used for other bedding articles as well
BACKGROUND OF THE INVENTION
Fitted sheets, which are also referred to as “bottom” sheets, are conventionally formed of fabric and are used to cover and protect a mattress. A fitted sheet typically comprises a top panel, two side panels and two end panels, and in general, the top panel is disposed over the top surface of the mattress, while each of the four side and end panels extends from the top panel and covers a sidewall or endwall, and at least a portion of the bottom surface, of the mattress. Further, each side panel is usually joined to each adjacent end panel at their respective edges by seams, in a manner to form corners adapted to conform to the shape of the mattress. A fitted sheet may also include some arrangement for securing the fitted sheet to the mattress and/or for keeping the fitted sheet in place on the mattress.
Nevertheless, fitted sheets often become displaced during use, which causes a disheveled look, and which may also cause discomfort to the user. Moreover, although nowadays mattresses are available commercially in several popular sizes, having width and length dimensions that are standardized within the bedding industry (e.g., “king,” “queen,” “full,” “twin,” etc.), in fact the dimensions of mattresses do vary from manufacturer to manufacturer, and even among the various mattress lines or models of the same manufacturer, particularly with respect to the thickness of the mattress. In other words, there is no “standard” mattress thickness dimension; rather, the thickness of particular mattresses may vary, depending on a number of factors such as the type or manufacturer of the bed, and the preferences of individual users. Therefore, fitted sheets designed for use on a mattress of a particular size, such as a “queen” size mattress, may not fit snugly on all mattresses of that size. Moreover, over time, an individual mattress may tend to change its size and shape, due to a variety of factors such as age and/or excessive use and/or environmental factors.
Accordingly, there is a need for a fitted sheet capable of remaining in place during use, and which, at the same time, can accommodate and fit snugly on mattresses of varying thicknesses, and can also adapt to any changes in mattress size and shape, while continuing to appear smooth and neat, at least along the top surface and sidewalls of the mattress. Although efforts have been made in the prior art to provide fitted sheets that can overcome these problems, such as those described in U.S. Pat. Nos. 5,287,574, 7,398,570 and 8,171,581, those efforts have not been completely satisfactory.
Most of these prior art solutions involve blending stretchable and non-stretchable portions into the fabric that forms the side panels of the sheet, such that the stretchable fabric portions are located at or near the corners. However, this solution may lead to undesirable consequences, such as differential shrinkage of the sheet after laundering, as well as a “mottled” appearance due to slight differences in the coloration of portions of the sheet, either initially or after laundering. These undesirable consequences are a direct result of blending stretchable and non-stretchable yarns into portions of the fabric, as these portions are assembled of yarn fibers having different characteristics. Since such blending is common to all of these prior art solutions, it is a fundamental flaw of the prior art.
It is therefore the principal object of the present invention to provide improved fitted bed sheets which are capable of remaining in place during use, which can fit the contours mattresses of varying thicknesses, and which, at the same time, do not exhibit the undesirable effects caused by the incorporation into the side panels of the sheet of both stretchable and non-stretchable portions of fabric.
SUMMARY OF THE INVENTION
This and other objects of the present invention are achieved by providing an improved fitted sheet including a top panel and side and end panels that are continuous and made from the same fabric, using any standard fabric construction process such as weaving or knitting. A special seam is provided at the corners to insure that the sheet fits snugly over the mattress and does not pop up during usage. In addition, flexible and stretchable strips or tapes, which stretch when pulled, are used at those corner seams and also along the free peripheral edges of the side panels.
Thus, one aspect of the present invention generally concerns improved articles for use as bedding materials, while another aspect of the present invention concerns methods for fabricating such articles.
BRIEF DESCRIPTION OF THE DRAWINGS
These and other aspects, features, objects and advantages of the present invention will become more apparent to those skilled in the art from the following detailed description of the presently most preferred embodiments thereof (which are given for the purposes of disclosure), when read in conjunction with the accompanying drawings (which form a part of the specification, but which are not to be considered as limiting its scope), wherein:
FIG. 1 is a top plan view of a substantially flat rectangular web of fabric from which the fitted sheet of the invention may be formed;
FIG. 2 is a view substantially similar to FIG. 1 , illustrating in phantom lines the portions of the fabric web which are to be cut away and removed, so as to form side and end panels;
FIG. 3 is a view substantially similar to FIGS. 1 and 2 , illustrating diagrammatically how the edge of each respective side panel is drawn towards the edge of an adjacent end panel, prior to stitching;
FIG. 4 is a bottom plan view of the fabric web of FIG. 3 , after the side and end panels have been joined to form corner seams, thus forming a bed sheet;
FIG. 5 is a top plan view of the bed sheet of FIG. 4 ;
FIG. 6 is a bottom plan view of the bed sheet of FIG. 5 , after a flexible and stretchable strip has been added at each corner seam, and after an additional special seam has been formed adjacent each corner;
FIGS. 7 and 7A are a bottom plan view, partially broken away, and a side perspective view, respectively, of the bed sheet of FIG. 6 , after a flexible and stretchable strip has been stitched to the free peripheral edges of the side and end panels, thus forming the fitted bed sheet of the invention shown covering the top surface, the sidewalls and endwalls, and at least a portion of the bottom surface of a mattress;
FIG. 8 is a flow diagram depicting the process by which the fitted bed sheet of FIG. 7 is formed, in accordance with the invention, from the rectangular web of fabric of FIG. 1 ;
FIG. 9 is top plan view showing the fitted bed sheet of the invention covering the top surface of a mattress;
FIG. 10 is a diagrammatic bottom plan view, partially broken away, and substantially similar to FIG. 7 , illustrating the fitted bed sheet of the invention covering a portion of the bottom surface of a mattress; and
FIGS. 11-13 are diagrammatic bottom plan views depicting several fitted bed sheets of the prior art.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
The preferred embodiment of the present invention will now be further described. As stated above, although the invention will be illustratively described hereinafter with reference to the formation of a fitted bed sheet, it should be understood that the invention is not limited to the specific case described, but extends also to the formation of other bedding items, such as blankets, quilts, bedspreads, duvets and duvet covers.
Referring first to FIGS. 1-3 and to the flow diagram of FIG. 8 , the process of forming the fitted bed sheet of the present invention begins with a flat web of material 10 , usually, although not necessarily, rectangular in shape, and preferably formed from a non-stretchable textile fabric that is woven or knitted from cotton, silk, wool, rayon, polyester, viscose and/or other types of threads, yarns or fibers, and combinations thereof, as is conventional in the bedding industry. To form the fitted bed sheet, initially the four corners of web 10 are cut, substantially along the lines 12 , as shown in FIG. 2 (step 100 in FIG. 8 ), forming generally square corner portions 14 , 16 , 18 , 20 that are removed. The resulting modified web 22 is still flat, and as shown in FIG. 3 , it includes a top panel 24 having a peripheral edge 26 , two opposed side panels 28 , 30 , as well as two opposed end panels 32 , 34 . Each of side panels 28 , 30 and end panels 32 , 34 has two respective side edges 35 a , as well as a distal edge 35 b.
Generally, the dimensions of top panel 24 are selected so as to be sufficient to be disposed over, and to cover, the top surface of a mattress (not shown), and the dimensions of side panels 28 , 30 and end panels 32 , 34 are selected to be sufficient to cover the sidewalls and endwalls, respectively, of the mattress, but they also extend a sufficient distance from the peripheral edge 26 of top panel 24 so as to cover at least a portion of the bottom surface of the mattress as well. In general, no matter what absolute dimensions are chosen for the side and end panels (such dimensions will depend upon the design, configuration, thickness and contours of the mattress on which the fitted bed sheet of the invention is to be used), opposed side panels 28 , 30 will have a dimension L that will correspond substantially to the length dimension of the mattress, while opposed end panels 32 , 34 will have a dimension W that will correspond substantially to the width dimension of the mattress; thus, opposed side panels 28 , 30 will be substantially congruent, and similarly, opposed end panels 32 , 34 will also be substantially congruent.
Referring now to FIG. 4 in addition to the aforementioned FIGS. 1-3 and 8 , the adjacent side edges 35 a of side and end panels 28 , 30 , 32 , 34 are then brought together as indicated by the arrows A in FIG. 3 , and are joined, two by two (step 102 in FIG. 8 ), to form corner seams 36 , 38 , 40 , 42 , respectively, thus resulting in a bed sheet 44 . Preferably, a five thread lock stitch is used to join these edges, as illustrated schematically in FIG. 4 . This lock stitch uses multiple threads that are interlocked with each other to provide strength for the seams, and this stitch allows bed sheet 44 to accommodate the shape of a mattress at the corners, and maintains the sheet on the mattress. FIG. 4 comprises a reverse view of bed sheet 44 (as compared with FIG. 3 ), so as to illustrate the positions and orientations of the stitches forming the corners seams. Each of corner seams 36 , 38 , 40 , 42 has a proximal end 43 a and a distal end 43 b . As will be apparent, the distal edges 35 b of the side and end panels 28 , 30 , 32 , 34 together form the peripheral free edge of bed sheet 44 .
Referring next to FIGS. 5 and 6 in addition to the aforementioned FIGS. 1-4 and 8 , an additional special seam is made (step 104 in FIG. 8 ) in the fabric of top panel 24 of bed sheet 44 in the general vicinity of each of the corners, along lines 45 , each of which, as shown best in FIG. 5 (a view of bed sheet 44 from above), is formed along a line which is an extension of one of the corner seams. Each of these additional seams 46 , 48 , 50 , 52 is preferably about 1.5 inches in length, and each one extends diagonally, from peripheral edge 26 of top panel 24 towards the center of top panel 24 , along the same longitudinal axis as the adjacent one of corner seams 36 , 38 , 40 , 42 ( FIG. 7A shows the position of these additional seams when the fitted bed sheet of the invention is installed on a mattress). The purpose of these additional seams 46 , 48 , 50 , 52 is to gather some of the fabric material of the bed sheet adjacent to the corners, and they help to insure that at each corner, the top panel 24 and each respective intersecting pair of side and end panels 28 , 30 , 32 , 34 , do not form a narrow pocket, but instead fit over the mattress corner snugly and assume the shape of the mattress. These additional seams 46 , 48 , 50 , 52 can be formed using conventional sewing techniques, such as Daug stitching or using lock stitching placed at all four corners.
As previously mentioned, even though mattresses have nominal standard (length×width) sizes, their actual dimensions may vary somewhat. This is particularly true of their thicknesses, which is also referred to herein as their heights. For example, some mattresses may have a height of 7 inches, while others may be as high as 18 inches. It would be inconvenient to manufacture a separate fitted sheet for mattresses of every possible height in each of the standard (length×width) mattress sizes. Therefore, in order to accommodate different heights, the fitted bed sheet of the present invention is provided with flexible and stretchable corner members 54 , 56 , 58 , 60 (step 106 in FIG. 8 ), one at each corner.
Corner members 54 , 56 , 58 , 60 may be fabricated of any conventional tightly woven elastic material, having a stretch ratio ranging from about 1:2.75 to about 1:3, and may be provided on either surface of the sheet, but preferably they are provided on the surface which will become the inner surface of the sheet, that is, the surface which will be adjacent to the mattress when the sheet is in use. Each corner member is positioned overlying one of the corner seams 36 , 38 , 40 , 42 , respectively, as illustrated in FIG. 6 , and is secured, preferably via conventional lock stitching; the corner members 54 , 56 , 58 , 60 , when the fitted bed sheet of the invention is installed on a horizontally-positioned mattress ( FIG. 7A ), are generally oriented vertically.
Each corner member 54 , 56 , 58 , 60 is preferably provided in the form of a narrow strip or tape, about 8-12 mm wide, and its length is preferably smaller than the dimension chosen for the length of the side edge 35 a of each of the side and end panels 28 , 30 , 32 , 34 ; most preferably, the length of each corner member, before it is secured to bed sheet 44 , is chosen to be less than one-half of the length of the side edge 35 a of the side and end panels 28 , 30 , 32 , 34 . It is to be understood that, while the length of the corner members, as specified in the preceding sentence, is measured while each corner member is in a relaxed or “unstretched” condition, each corner member is secured to the sheet in “stretched” condition, that is, prior to securing each corner member to a respective corner seam, each corner member is stretched out, so that it essentially covers the respective corner seam from end to end. The elastic material from which corner members 54 , 56 , 58 and 60 may be formed is commercially available from a wide variety of sources, such as M/s. Shree Shyam Industries of Bhiwandi, Maharashtra, India and Mahendra Trading Company of Mumbai, Maharashtra, India.
Finally, and referring now to FIG. 7 in addition to the aforementioned FIGS. 1-6 and 8 , a border member 62 is secured, preferably via twin needle lock stitching, to the outer edge or perimeter 64 of fitted bed sheet 44 (that is, to the free peripheral edges of the side and end panels 28 , 30 , 32 , 34 ), as illustrated in FIG. 7 (step 108 in FIG. 8 ). Border member 62 is preferably provided in the form of a flexible and stretchable strip or tape comprised of a tightly woven elastic material, having a stretch ratio in the range of from about 1:175 to about 1:2, and is preferably about 1 inch (25 mm) wide. Preferably, the overall length of the border member 62 is shorter than the overall length of the perimeter 64 of sheet 44 (the length of perimeter 64 being the combined total of twice the value of dimension W and twice the value of dimension L, as illustrated in FIG. 2 ) most preferably, the length of border member 62 is chosen to be approximately one-half of the length of perimeter 64 .
It is to be understood that, while the length of the border member 62 , as specified in the preceding sentence, is measured while it is in the relaxed or “unstretched” condition, the border member is secured to the sheet in “stretched” condition, that is, prior to securing the border member 62 to the perimeter 64 of sheet 44 , the border member 62 is stretched out, so that it essentially extends around the entire peripheral free edge of the sheet. Thus, due to the combined effect of flexible and stretchable corner members 54 , 56 , 58 , 60 and flexible and stretchable border member 62 , the final fitted bed sheet 44 is formed with a peripheral free edge having an irregular shape (see FIG. 7 ). The elastic material from which border member 62 may be formed is commercially available from a wide variety of sources, such as M/s. Shree Shyam Industries of Bhiwandi, Maharashtra, India and Mahendra Trading Company of Mumbai, Maharashtra, India.
The resulting fitted bed sheet 44 has several advantages over the prior art. Referring now to FIGS. 7A , 9 and 10 in addition to the aforementioned FIGS. 1-8 , the additional seams near the corners insure that the sheet fits snugly and smoothly over the corners of the mattress, while the corner members 54 , 56 , 58 , 60 and the border member 62 cooperate to hold the top panel 24 and side and end panels 28 , 30 , 32 , 34 evenly and smoothly on the various corresponding surfaces of the mattress. Moreover, the fitted bed sheet 44 not only adjusts automatically to variations in the dimensions of a mattress, but can also be used for mattresses with varying heights, depending on the dimension chosen for the edges of the side and end panels 28 , 30 , 32 , 34 (that is, the dimension chosen for the length of the lines 12 shown in FIG. 2 ). For example, if 16 inches is chosen for that dimension, then the fitted sheet will accommodate mattresses with heights ranging from 7 inches to 18 inches, whereas if 14 inches is chosen for that dimension, then the fitted sheet will accommodate mattresses with heights ranging from 5.5 inches to 16 inches, while if 18 inches is chosen for that dimension, then the fitted sheet will accommodate mattresses with heights ranging from 9 inches to 20 inches.
Referring finally to FIGS. 11-13 in addition to the aforementioned FIGS. 1-10 , further advantages of the fitted bed sheet 44 of the present invention over the fitted bed sheets of the prior art become apparent. The known fitted bed sheet in FIG. 11 (described in U.S. Pat. No. 5,287,574) is provided with the entirety of each end panel 66 , 68 being made of a special stretchable (e.g., Lycra®) fabric, as indicated by the arrows B. This fitted sheet is expensive to make, and after a while the knitted fabric loses its flexibility (especially after repeated washing) and fails to maintain its stretching characteristics. In addition, although the outer peripheral edge 70 of this fitted sheet is provided with a circumferential tubular elasticized “cord,” this material is of insufficient size to insure that the sheet remains in place during use. FIG. 12 shows another known fitted sheet (described in U.S. Pat. No. 8,171,581) that is provided with segments 72 of special stretchable (e.g., Lycra®) fabric positioned adjacent the corners. Again, this construction is expensive to manufacture, requiring special assembly, particularly near the corner seams, in order to join the stretchable fabric segments with the non-stretchable fabric making up the rest of the fitted sheet. FIG. 13 shows yet another known fitted sheet (described in U.S. Pat. No. 7,398,570), similar to the one in FIG. 11 , except that the end panels 74 , 76 are “composites” of dual construction, in which a stretchable portion (as indicated by the arrows C) is attached to a non-stretchable portion. Again, this structure is expensive and time-consuming to assemble.
While there has been described what are at present considered to be the preferred embodiments of the present invention, it will be apparent to those skilled in the art that the embodiments described herein are by way of illustration and not of limitation. Various modifications of the disclosed embodiments, as well as alternative embodiments of the invention, will become apparent to persons skilled in the art upon reference to the description of the invention. Therefore, it is to be understood that various changes and modifications may be made in the embodiments disclosed herein without departing from the true spirit and scope of the present invention, as set forth in the appended claims, and it is contemplated that the appended claims will cover any such modifications or embodiments. | An article of bedding for disposition over the top, side and end surfaces of a mattress comprises a substantially inelastic web of textile material which includes a top panel, side and end panels, and corner seams. The article further comprises a stretchable corner member overlying each corner seam, an additional seam aligned axially with each corner seam, and a stretchable border member secured to the peripheral edges of the side panels. This construction allows the article to accommodate the contours of mattresses of varying thicknesses within each given peripheral mattress size classification. Methods of making such articles are also disclosed. | 3 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to methods, apparatus and systems for conveying a tool within a borehole. In several embodiments, for example, the invention relates to methods, apparatus and systems capable of deploying one or more tools within a non-vertical borehole without the necessity of power, or data, lines from the surface.
2. Description of Related Art
The deployment of tools in boreholes is well known. In the petroleum exploration and recovery industries, for example, tools are deployed in subsurface wells for a multitude of purposes, such as to conduct well logging and completion operations. The downhole use of tools in the petroleum exploration and recovery process is generally considered fundamental and essential.
Various challenges exist in delivering tools into boreholes. For example, the tool may require power from an external source for conducting its desired operations. For another example, it may be necessary to provide instructions to the tool when it is deployed in the borehole.
Numerous techniques and equipment have been used or proposed for delivering tools into boreholes. Again with reference to the petroleum exploration and recovery industries, for example, tools are often deployed in vertically-oriented wells with the use of a wireline that includes power and data cables extending from the surface. The wireline may also be deployed through coiled tubing or drill pipe to the tool. For another example, tool conveyance devices for propelling the tool along non-vertical or deviated wells have been proposed and used, such as the “tractor” technology disclosed in U.S. Pat. No. 6,179,055 B1, which is incorporated herein by reference.
In considering existing technology for conveying tools in boreholes, the present invention fulfills a need for methods, apparatus and/or systems having one or more of the following attributes: deploying tools into boreholes without the necessity of power lines extending from the surface; deploying tools into boreholes without the necessity of data transmission lines extending from the surface; deploying tools into boreholes without the necessity of wirelines extending from the surface; using an apparatus that carries one or more tools, the tools being rotatable while deployed in the borehole; allowing tools deployed in a borehole to be rotated, or moved in circular pattern, in the borehole; generating power in the borehole for powering at least one tool without the necessity of power lines from the surface; using fluid to generate power; using drilling mud to generate power; being deployable in a non-vertical borehole; providing cost effective delivery of tools into and within boreholes; providing speedy delivery of tools into and within boreholes; generating minimal friction during the delivery of tools into boreholes; using an easy to control and simple apparatus and technique for moving one or more tools into a borehole; reliable delivery of tools into boreholes; delivering tools in boreholes without the necessity of complex and/or cumbersome mechanical delivery equipment; providing any one or more of the above attributes with the use of existing equipment and technology and/or by retrofitting existing equipment.
BRIEF SUMMARY OF THE INVENTION
In accordance with the present invention, certain embodiments involve an apparatus useful for conveying a tool into a borehole from the surface without the necessity of power-delivery and communication lines from the surface. The apparatus is in fluid communication with a fluid source, is deployable in the borehole and includes a fluid delivery member and an interface system in fluid communication with the fluid delivery member. The interface system is designed to permit the deployment of standard, unmodified wireline tools and includes power generation and communication systems. A fluid discharge member is in fluid communication with the interface system and engageable with the tool(s). Fluid is provided to the power generation system through the fluid delivery member, utilized by the power generation system to generate power for powering a tool and discharged from the apparatus through the fluid discharge member. The communication system is capable of transmitting data between the surface and a tool without the necessity of data-delivery lines from the surface.
If desired, the fluid discharge member may be a circulating sub module having a fluid discharge port and being capable of electrically and electronically connecting the power generation system and a tool. The power generation system may include a turbo-alternator capable of generating electricity from the flow of fluid through the power generation system.
The fluid delivery member may be drill pipe that is controllably movable within the borehole so that the tool is controllably deployable in the borehole, or it may be coiled tubing. If desired, the fluid may be drilling mud and the borehole may be non-vertical or deviated. The fluid delivery member and/or the fluid discharge member may be integral with the power generation system.
In some embodiments, the power generation system includes a telemetry mud pulser/turbo-alternator module and a data acquisition/memory module. The mud pulser/turbo-alternator module may be capable of deriving power from the flow of fluid within the power generation system and transmitting power and data to the data acquisition/memory module. The mud pulser/turbo-alternator module and the data acquisition/memory module may include fluid flow passageways in fluid communication with one another. The mud pulser/turbo-alternator module may include a modulator and modulator controller, and may transmit data to the surface from the data acquisition/memory module. The data acquisition/memory module may transmit data between the mud pulser/turbo-alternator module and a tool.
Some embodiments involve a fluid discharge member that includes a discharge port, is connectable between the power generation system and a wireline telemetry sub, and is capable of electrically and electronically connecting the power generation system with a tool.
Various embodiments involve a tool conveying system useful for carrying a wireline tool and deploying the wireline tool in a non-vertical or deviated borehole from the surface. The tool conveying system includes a downhole power system and a fluid circulation system in fluid communication with one another. The fluid circulation system enables the flow of fluid through the downhole power system. The downhole power system is capable of generating power from the fluid flowing therethrough, providing power to a wireline tool carried by the tool conveying system, and communicating data between a wireline tool and the surface.
In such embodiments, the downhole power system may, if desired, be capable of generating electricity from the flow of fluid through the downhole power system without the use of power-delivery lines from the surface, and/or communicating data between a wireline tool and the surface without the use of a wireline from the surface. The downhole power system may include a telemetry mud pulser/turbo-alternator module and a data acquisition/memory module.
In certain embodiments, the present invention involves a method for conveying a tool into a borehole from the surface without the necessity of power-delivery and communication lines from the surface and with the use of a tool conveying apparatus deployable in the borehole. The method includes deploying the tool conveying apparatus in the borehole, transmitting fluid through the tool conveying apparatus, the tool conveying apparatus generating power from the flow of fluid therethrough and providing power to a tool carried thereby, and discharging fluid from the tool conveying apparatus.
If desired, the tool conveying apparatus may also transmit data between a tool carried thereby and the surface without the necessity of communication lines to the surface. Telemetry/mud pulser technology may be used to transmit data between a tool and the surface. The tool conveying apparatus may be deployable in the borehole by moving a rigid upper member of the apparatus.
The borehole may be non-vertical or deviated and the fluid may be drilling mud. A turbo-alternator may be included in the tool conveying apparatus that generates unregulated AC power from the fluid flow through the tool conveying apparatus. The tool conveying apparatus may be capable of transforming unregulated AC power to regulated AC and/or DC power. A data acquisition/memory module may be included in the apparatus that receives power and data, stores data and distributes power and data to a wireline tool.
Accordingly, the present invention includes features and advantages that enable it to advance the technology associated with conveying tools in boreholes. Characteristics and advantages of the present invention described above, as well as additional features and benefits, will be readily apparent to those skilled in the art upon consideration of the following detailed description of preferred embodiments and referring to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
For a detailed description of preferred embodiments of the invention, reference will now be made to the accompanying drawings wherein:
FIG. 1 is a schematic view of an embodiment of a tool conveying apparatus in accordance with the present invention, the tool conveying apparatus shown deployed in a borehole;
FIG. 2 is a partial cross-sectional view of an example data acquisition/memory module of the tool conveying apparatus shown in FIG. 1;
FIG. 3 is a partial cross-sectional view of an example circulating sub/interface module of the tool conveying apparatus shown in FIG. 1; and
FIG. 4 is a flow diagram showing an embodiment of a method of operation of conveying a tool in a borehole in accordance with the present invention.
DETAILED DESCRIPTION OF THE INVENTION
Presently preferred embodiments of the invention are shown in the above-identified figures and described in detail below. In describing the preferred embodiments, like or identical reference numerals are used to identify common or similar elements. The figures are not necessarily to scale and certain features and certain views of the figures may be shown exaggerated in scale or in schematic in the interest of clarity and conciseness.
As used herein and throughout the various portions of this specification, the terms “invention”, “present invention”, and variations thereof are not intended to mean the claimed invention of any particular of the appended claims, or all of the appended claims. These terms are used to merely provide a reference point for subject matter discussed in this specification. The subject or topic of each such reference is thus not necessarily part of, or required by, any particular claim(s) merely because of such reference. Accordingly, the use herein of the terms “invention”, “present invention” and variations thereof is not intended and should not be used to limit the construction or scope of the appended claims.
Referring initially to FIG. 1, an example tool conveying apparatus 10 in accordance with the present invention is shown. The illustrated tool conveying apparatus 10 is capable of carrying and powering one or more tools 18 and, if desired, communicating data between the tool 18 and the surface (not shown), without the use of a wireline from the surface. Any suitable components and technique may be used in the apparatus 10 to provide such capabilities.
As used throughout this specification and in the appended claims and abstract, the terms “wireline tool”, “tool”, and variations thereof means one or more device or tool that can be used in a borehole. Some examples of tools which may be used with the present invention, methods of operation thereof, and techniques for communication therewith are described in U.S. Pat. Nos. 4,860,581; 4,936,139; 6,191,588 B1; and 4,937,446, each of which is incorporated herein by reference. However, the present invention is not limited in any way to the particular wireline tools or methods disclosed in the referenced patents, or otherwise by the type or operation of a tool that can be used with the present invention. Also as used throughout this specification and in the appended claims and abstract, the term “surface” and variations thereof means above-ground or thereabouts, or the operator(s) or equipment for operating or controlling the tool conveying apparatus, or another person, entity or equipment, wherever located, that is designated to operate or communicate with the tool conveying apparatus or wireline tool. The present invention is in no way limited by the nature or location of the “surface.”
The exemplary tool conveying apparatus 10 is shown disposed within a borehole 14 . As used throughout this specification and in the appended claims and abstract, the term “borehole” means any borehole, passageway or area suitable for use with the present invention. While the borehole 14 of FIG. 1 appears vertically-oriented, the present invention is not limited to any particular orientation of the borehole 14 . For example, in a preferred embodiment, the tool conveying apparatus 10 is useful for conveying the tool 18 within a borehole 14 that is non-vertical, such as a “horizontal” or “deviated” well. Unless specifically indicated otherwise, the present invention is in no way limited by the type or orientation of borehole within which it is, or may be, used.
The tool conveying apparatus 10 of FIG. 1 includes a fluid circulation system 20 and a downhole interface system 30 . The fluid circulation system 20 enables the flow of fluid through the downhole interface system 30 , which utilizes the fluid to generate power, as will be described further below. As used herein, the term “fluid” means drilling mud or any other fluid or fluid/solid mixture suitable for use in accordance with the present invention. In preferred embodiments, the fluid is drilling mud, however, the present invention is not limited by the type of fluid that is, or may be, used.
The particular fluid circulation system 20 of FIG. 1 includes a fluid delivery member 21 and a fluid discharge member 24 . In the illustrated embodiment, the fluid delivery member 21 is controllably movable, such as from the surface (not shown), to direct or control movement of the tool conveying apparatus 10 and attached tool 18 within the borehole 14 . However, this capability is not required.
Still referring to the example of FIG. 1, the fluid delivery member 21 may be any suitable component(s) having any desired configuration, shape, and components as is or becomes known, such as drill pipe 22 or coiled tubing. The fluid delivery member 21 may be connectable with the downhole interface system 30 with the use of any suitable mechanical or other connection as is or becomes known. In some embodiments, the fluid delivery member 21 may instead be integral with the downhole interface system 30 .
The fluid delivery member 21 includes at least one area, or passageway, 26 into which fluid may be provided, such as from the surface, as indicated by flow arrow 28 . At least one such passageway 26 is in fluid communication with the downhole interface system 30 . The fluid delivery member 21 thus allows the flow of, or directs, fluid into the downhole interface system 30 .
Still referring to FIG. 1, the exemplary fluid discharge member 24 enables ejection of the fluid from the downhole interface system 30 , as indicated by flow arrow 29 , and may be any suitable component(s) as is or become known. One particular embodiment of the fluid discharge member 24 is shown in FIG. 3, in which the fluid discharge member 24 is a circulating sub/interface module 50 connectable between the downhole interface system 30 and a wireline telemetry sub 19 , such as via mechanical connections as is or become known. The illustrated circulating sub/interface module 50 includes at least one fluid passageway, or area, 52 in fluid communication with the downhole interface system 30 , and at least one fluid ejection port 54 to allow the ejection of fluid (via fluid path 58 ) from the tool conveying apparatus 10 into the borehole 14 . If desired, the fluid can be recirculated and reused as is, or becomes, known.
Still referring to FIG. 3, the illustrated circulating sub/interface module 50 also electrically and electronically connects the downhole interface system 30 and the tool 18 with connections 62 , 68 and power/data wires 64 to allow power and data to be transmitted between the downhole interface system 30 and the tool 18 , as is or becomes known. However, the present invention is not limited to the use of a circulating sub/interface module 50 or any of the details of the exemplary embodiment. For example, if desired, the fluid discharge member 24 may be integral with the downhole interface system 30 . For another example, the fluid discharge member 24 may connect directly to the tool 18 without a telemetry sub 19 .
Referring back to FIG. 1, the downhole interface system 30 includes a power generation system that generates power from the fluid flowing through passageway 26 , such as for powering the tool 18 , and, if desired, may also include a communication-system to communicate data between the tool 18 and the surface (not shown). In the particular embodiment shown, the downhole interface system 30 includes a telemetry mud pulser/turbo-alternator module 34 and a data acquisition/memory module 40 . The mud pulser/turbo-alternator module 34 is capable of generating electricity from the flow of fluid entering the module 34 from the fluid delivery member 21 , as is or becomes known. Referring to FIG. 2, the power generated in the telemetry mud pulser/turbo-alternator module 34 of this embodiment is transmitted to the data acquisition/memory module 40 via wires 38 and an electrical/data connection 39 .
Referring again to FIG. 1, the exemplary downhole interface system 30 allows fluid to flow through the mud pulser/turbo-alternator module 34 and data acquisition/memory module 40 . In the example shown in FIG. 2, the modules 34 and 40 include fluid pathways 36 , 42 , respectively, which are in fluid communication with one another. The flow of fluid is illustrated by arrow 48 .
The exemplary mud pulser/turbo-alternator module 34 is also capable of communicating data to and from the surface (not shown). Referring to FIG. 2, the illustrated module 34 includes one or more mechanical and electronic components 37 capable of effecting communication with the surface. For example, the mechanical and electronic components 37 may include a modulator, modulator controller and/or printed circuit boards capable of “mud pulse” communication with the surface as is or becomes known. In such example, the measurement while drilling, “MWD”, technology of Schlumberger Technology Corporation may be utilized as part of the module 34 to enable two-way telemetry. The illustrated module 34 is also equipped to communicate data with the data acquisition/memory module 40 through the wires 38 and electrical/data connection 39 .
Still referring to FIG. 2, the exemplary data acquisition/memory module 40 includes electronic components 44 for transmitting and receiving data between the module 34 and the wireline tool 18 , as is or becomes known. The illustrated data acquisition/memory module 40 also stores and processes information. The data acquisition/memory module 40 may be designed, for example, to store some or much of the information received from the tool 18 , reducing the quantity of information that needs to be transmitted to the surface. If desired, for example, only the wireline tool status and basic data need be transmitted to the surface, while other data is stored in the data acquisition/memory module 40 .
The downhole interface system 30 may include additional components and/or capabilities. For example, tension/compression load cells (not shown) may be included for quick detection of over-compression of the wireline tool 18 . The present invention may also be designed so that such detection can be rapidly communicated to the surface, if desired.
Further details of the structure and operation of some examples of components that may be used as part of the downhole interface system 30 are described in U.S. Pat. Nos. 5,375,098; 5,249,161; and 5,237,540, each of which is incorporated herein by reference. However, the present invention is not limited to the details above, the use of a telemetry mud pulser/turbo-alternator module 34 or data acquisition/memory module 40 , or the techniques or embodiments disclosed in the referenced patents.
The above description of exemplary components and the operation thereof is provided for illustrative purposes only and is not limiting upon the present invention. The present invention is thus not limited by the form, components and configuration of the tool conveying apparatus described above. Any components and techniques capable of generating power in the borehole for powering a wireline tool and, if desired, communicating data between the tool and the surface that are or become known may be used.
FIG. 4 is a flow diagram illustrating exemplary methods of power and data transmission involving a downhole tool in accordance with the present invention. The right hand side of the flow diagram, the “power” side 80 relates generally to the generation and transmission of power within a tool conveying apparatus of the present invention. The left hand side, the “data” side 84 , relates generally to the receipt, processing, storage, generation and transmission of data (or any combination thereof) in a tool conveying apparatus of the present invention. Path 90 generally represents the transmission of power through the tool conveying apparatus, path 92 generally represents the transmission of data to a wireline tool or tools 18 carried by the tool conveying apparatus, and path 94 generally represents the transmission of data to the surface 100 .
Referring initially to the power side 80 and power flow path 90 , block 102 represents the supply of fluid through a fluid delivery member (e.g. through a fluid delivery member 21 , FIG. 1) to a power generation system (block 104 ) of a downhole interface system (e.g. 30 , FIG. 1 ). The power generation system 104 , for example, may include a turbo-alternator capable of generating unregulated AC power from the fluid flow. In some embodiments, the frequency of the AC power generated by the turbo-alternator will depend upon the flow rate of the fluid into the turbo-alternator; e.g. the greater the flow rate, the higher the frequency of the AC power.
In the exemplary embodiment, the unregulated AC power is conditioned (block 106 ) for use in the tool conveying apparatus 10 and/or wireline tools 18 . For example, one or more electronic circuits may be used to transform the unregulated AC power to regulated AC and/or DC power. In this embodiment, regulated DC power is provided to power a modulator controller (block 120 ) of the telemetry mud pulser/turbo-alternator module 34 , and regulated AC power is provided to the data acquisition/memory module 40 at block 108 .
Referring to block 108 , the data acquisition/memory module 40 of this embodiment conditions and distributes the power it receives. For example, one or more electrical circuits may be used to provide high level AC power and high level DC power to a wireline telemetry sub 19 (if included), as indicated by arrows 109 , 110 , respectively, and low level DC power (arrow 111 ) may be provided to one or more electronic components 44 in the data acquisition/memory module 40 .
The wireline telemetry sub 19 , if included, may be equipped to condition power it receives (block 112 ) and/or distribute power to the wireline tool or tools 18 , such as in the form of AC power and DC power (arrows 114 , 115 , respectively). The wireline tool or tools 18 use power received from the wireline telemetry sub 19 to perform their designated tasks, such as to record data from the borehole within which they are deployed.
Now referring to flow path 92 (the transmission of data to the wireline tool or tools 18 ) beginning at block 104 , data about the fluid flow rate in the power generation device (block 104 ) of the illustrated embodiment is communicated to one or more electronic components 37 , such as printed circuit boards, (block 124 ) of the telemetry mud pulser/turbo alternator module 34 . If included, this capability may have any desired purpose. For example, when mud pulser technology is used, commands or instructions, such as requests for certain types of information to be obtained by the wireline tools, may be transmitted to the tool conveying apparatus from the surface by varying the flow rate of the fluid into the turbo-alternator, as is or becomes known. The power generation device (block 104 ) transmits such information to the electronic component(s) 37 , such as circuitry, which translates, reads or processes the data received (block 124 ).
One or more electronic components 37 of the telemetry mud pulser/turbo-alternator module 34 of this embodiment transmits data to one or more electronic components 44 (block 126 ) of the data acquisition/memory module 40 . The data transmitted, for example, may include instructions for the wireline tool that are provided via the flow rate information from the power generation device. The electronic component 44 evaluates, sorts, stores or processes the data, or any combination thereof (block 126 ). For example, the component 44 may convert wireline tool instructions received from the electronic component 37 to a digital command.
The electronic component 44 of the data acquisition/memory module 40 is capable of transmitting data, such as operational instructions, to one or more electronic components of the wireline telemetry sub 19 , or directly to the wireline tool 18 if the sub 19 is not included. When a sub 19 is included, data may be processed therein (block 130 ) and transmitted to the tool 18 , as is or becomes known.
Reference is now made to the flow path 94 (the transmission of data to the surface), beginning at the wireline tool 18 . In the embodiment shown, information, such as digital data gathered by the wireline tool 18 , is transmitted to one or more electronic components (block 130 ) of the wireline telemetry sub 19 . The wireline telemetry sub 19 may evaluate, sort, store and/or process the data, and/or transmit data to the data acquisition/memory module 40 for formatting (block 136 ) and processing and/or sorting therein (block 126 ). If desired, some data may be stored in memory (block 140 ) therein, and some data may be transmitted to the telemetry mud pulser/turbo-alternator module 34 . In the exemplary module 34 , data received from the module 40 is processed (block 124 ) and transmitted to the surface (block 100 ) via the modulator controller (block 120 ) and modulator (block 122 ), as is or becomes known.
The present invention does not require each of the techniques or acts described above. Moreover, the present invention is in no way limited to the above methods of power generation, power and data transmission or other operations. Further, neither the methods described above nor any methods that may fall within the scope of any of the appended claims need be performed in any particular order. Yet further, the methods of the present invention do not require use of the particular embodiments shown and described in the present specification, such as, for example, the tool conveying apparatus 10 of FIG. 1, but are equally applicable with any other suitable structure, form and configuration of components.
Preferred embodiments of the present invention are thus well adapted to carry out one or more of the objects of the invention. The apparatus and methods of the present invention offer advantages over the prior art and additional capabilities, functions, methods, uses and applications that have not been specifically addressed herein but are, or will become, apparent from the description herein, the appended drawings and claims.
It should be understood that the present invention does not require all of the above features and aspects. Any one or more of the above features or aspects may be employed in any suitable configuration without inclusion of other such features or aspects. Further, while preferred embodiments of this invention have been shown and described, many variations, modifications and/or changes of the apparatus and methods of the present invention, such as in the components, details of construction and operation, arrangement of parts and/or methods of use, are possible, contemplated by the applicant, within the scope of the appended claims, and may be made and used by one of ordinary skill in the art without departing from the spirit or teachings of the invention and scope of the appended claims. All matter herein set forth or shown in the accompanying drawings should thus be interpreted as illustrative and not limiting. Accordingly, the scope of the invention and the appended claims is not limited to the embodiments described and shown herein. | A method for conveying a tool into a borehole with the use of a tool conveying apparatus includes deploying the tool conveying apparatus into the borehole, transmitting fluid through the tool conveying apparatus, the tool conveying apparatus generating power from the flow of fluid therethrough, discharging fluid from the tool conveying apparatus and providing power to at least one tool carried thereby. The tool conveying apparatus also includes a communication system for transmitting data bi-directionally between the tool and the surface. | 4 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation application of U.S. patent application Ser. No. 12/646,066, filed Dec. 23, 2009, which is a divisional of U.S. patent application Ser. No. 11/533,679, filed on Sep. 20, 2006, which is a divisional of U.S. patent application Ser. No. 11/101,855, filed on Apr. 8, 2005, now issued as U.S. Pat. No. 7,124,831, which is a continuation of U.S. patent application Ser. No. 10/811,559, filed on Mar. 29, 2004, now abandoned, which is a continuation of U.S. patent application Ser. No. 09/893,505, filed on Jun. 27, 2001, now issued as U.S. Pat. No. 6,712,153, which are each incorporated by reference herein in their entirety.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to a downhole non-metallic sealing element system. More particularly, the present invention relates to downhole tools such as bridge plugs, frac-plugs, and packers having a non-metallic sealing element system.
[0004] 2. Background of the Related Art
[0005] An oil or gas well includes a wellbore extending into a well to some depth below the surface. Typically, the wellbore is lined with tubulars or casing to strengthen the walls of the borehole. To further strengthen the walls of the borehole, the annular area formed between the casing and the borehole is typically filled with cement to permanently set the casing in the wellbore. The casing is then perforated to allow production fluid to enter the wellbore and be retrieved at the surface of the well.
[0006] Downhole tools with sealing elements are placed within the wellbore to isolate the production fluid or to manage production fluid flow through the well. The tools, such as plugs or packers for example, are usually constructed of cast iron, aluminum, or other alloyed metals, but have a malleable, synthetic element system. An element system is typically made of a composite or synthetic rubber material which seals off an annulus within the wellbore to prevent the passage of fluids. The element system is compressed, thereby expanding radially outward from the tool to sealingly engage a surrounding tubular. For example, a bridge plug or frac-plug is placed within the wellbore to isolate upper and lower sections of production zones. By creating a pressure seal in the wellbore, bridge plugs and frac-plugs allow pressurized fluids or solids to treat an isolated formation.
[0007] FIG. 1 is a cross sectional view of a conventional bridge plug 50 . The bridge plug 50 generally includes a metallic body 80 , a synthetic sealing member 52 to seal an annular area between the bridge plug 50 and an inner wall of casing there-around (not shown), and one or more metallic slips 56 , 61 . The sealing member 52 is disposed between an upper metallic retaining portion 55 and a lower metallic retaining portion 60 . In operation, axial forces are applied to the slip 56 while the body 80 and slip 61 are held in a fixed position. As the slip 56 moves down in relation to the body 80 and slip 61 , the sealing member is actuated and the slips 56 , 61 are driven up cones 55 , 60 . The movement of the cones and slips axially compress and radially expand the sealing member 52 thereby forcing the sealing portion radially outward from the plug to contact the inner surface of the well bore casing. In this manner, the compressed sealing member 52 provides a fluid seal to prevent movement of fluids across the bridge plug 50 .
[0008] Like the bridge plug described above, conventional packers typically comprise a synthetic sealing element located between upper and lower metallic retaining rings. Packers are typically used to seal an annular area formed between two co-axially disposed tubulars within a wellbore. For example, packers may seal an annulus formed between production tubing disposed within wellbore casing. Alternatively, packers may seal an annulus between the outside of a tubular and an unlined borehole. Routine uses of packers include the protection of casing from pressure, both well and stimulation pressures, as well as the protection of the wellbore casing from corrosive fluids. Other common uses include the isolation of formations or leaks within a wellbore casing or multiple producing zones, thereby preventing the migration of fluid between zones. Packers may also be used to hold kill fluids or treating fluids within the casing annulus.
[0009] One problem associated with conventional element systems of downhole tools arises in high temperature and/or high pressure applications. High temperatures are generally defined as downhole temperatures above 200° F. and up to 450° F. High pressures are generally defined as downhole pressures above 7,500 psi and up to 15,000 psi. Another problem with conventional element systems occurs in both high and low pH environments. Low pH is generally defined as less than 6.0, and high pH is generally defined as more than 8.0. In these extreme downhole conditions, conventional sealing elements become ineffective. Most often, the physical properties of the sealing element suffer from degradation due to extreme downhole conditions. For example, the sealing element may melt, solidify, or otherwise loose elasticity.
[0010] Yet another problem associated with conventional element systems of downhole tools arises when the tool is no longer needed to seal an annulus and must be removed from the wellbore. For example, plugs and packers are sometimes intended to be temporary and must be removed to access the wellbore. Rather than de-actuate the tool and bring it to the surface of the well, the tool is typically destroyed with a rotating milling or drilling device. As the mill contacts the tool, the tool is “drilled up” or reduced to small pieces that are either washed out of the wellbore or simply left at the bottom of the wellbore. The more metal parts making up the tool, the longer the milling operation takes. Metallic components also typically require numerous trips in and out of the wellbore to replace worn out mills or drill bits.
[0011] There is a need, therefore, for a non-metallic element system that will effectively seal an annulus at high temperatures and withstand high pressure differentials without experiencing physical degradation. There is also a need for a downhole tool made substantially of a non-metallic material that is easier and faster to mill.
SUMMARY OF THE INVENTION
[0012] A non-metallic element system is provided which can effectively seal or pack-off an annulus under elevated temperatures. The element system can also resist high differential pressures as well as high and low pH environments without sacrificing performance or suffering mechanical degradation. Further, the non-metallic element system will drill up considerably faster than a conventional element system that contains metal.
[0013] The element system comprises a non-metallic, composite material that can withstand high temperatures and high pressure differentials. In one aspect, the composite material comprises an epoxy blend reinforced with glass fibers stacked layer upon layer at about 30 to about 70 degrees.
[0014] A downhole tool, such as a bridge plug, frac-plug, or packer, is also provided that comprises in substantial part a non-metallic, composite material which is easier and faster to mill than a conventional bridge plug containing metallic parts. In one aspect, the tool comprises one or more support rings having one or more wedges, one or more expansion rings and a sealing member disposed in a functional relationship with the one or more expansion rings This assemblage of components is referred to hereing as “an element system.”
[0015] In another aspect, a non-metallic mandrel for the downhole tool is formed of a polymeric composite material reinforced by fibers in layers angled at about 30 to about 70 degrees relative to an axis of the mandrel. Methods are provided for the manufacture and assembly of the tool and the mandrel, as well as for sealing an annulus in a wellbore using a downhole tool that includes a non-metallic mandrel and an element system.
BRIEF DESCRIPTION OF DRAWINGS
[0016] So that the manner in which the above recited features, advantages and objects of the present invention are attained and can be understood in detail, a more particular description of the invention, briefly summarized above, may be had by reference to the embodiments thereof which are illustrated in the appended drawings.
[0017] It is to be noted, however, that the appended drawings illustrate only typical embodiments of this invention and are therefore not to be considered limiting of its scope, for the invention may admit to other equally effective embodiments.
[0018] FIG. 1 is a partial section view of a conventional bridge plug.
[0019] FIG. 2 is a partial section view of a non-metallic sealing system of the present invention.
[0020] FIG. 3 is an enlarged isometric view of a support ring of the non-metallic sealing system.
[0021] FIG. 4 is a cross sectional view along lines A-A of FIG. 2 .
[0022] FIG. 5 is partial section view of a frac-plug having a non-metallic sealing system of the present invention in a run-in position.
[0023] FIG. 6 is section view of a frac-plug having a non-metallic sealing system of the present invention in a set position within a wellbore.
[0024] FIG. 6A is an enlarged view of a non-metallic sealing system activated within a wellbore.
[0025] FIG. 7 is a cross sectional view along lines B-B of FIG. 6 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0026] A non-metallic element system that is capable of sealing an annulus in very high or low pH environments as well as at elevated temperatures and high pressure differentials is provided. The non-metallic element system is made of a fiber reinforced polymer composite that is compressible and expandable or otherwise malleable to create a permanent set position.
[0027] The composite material is constructed of a polymeric composite that is reinforced by a continuous fiber such as glass, carbon, or aramid, for example. The individual fibers are typically layered parallel to each other, and wound layer upon layer. However, each individual layer is wound at an angle of about 30 to about 70 degrees to provide additional strength and stiffness to the composite material in high temperature and pressure downhole conditions. The tool mandrel is preferably wound at an angle of 30 to 55 degrees, and the other tool components are preferably wound at angles between about 40 and about 70 degrees. The difference in the winding phase is dependent on the required strength and rigidity of the overall composite material.
[0028] The polymeric composite is preferably an epoxy blend. However, the polymeric composite may also consist of polyurethanes or phenolics, for example. In one aspect, the polymeric composite is a blend of two or more epoxy resins. Preferably, the composite is a blend of a first epoxy resin of bisphenol A and epichlorohydrin and a second cycoaliphatic epoxy resin. Preferably, the cycloaphatic epoxy resin is Araldite® liquid epoxy resin, commercially available from Ciga-Geigy Corporation of Brewster, N.Y. A 50:50 blend by weight of the two resins has been found to provide the required stability and strength for use in high temperature and pressure applications. The 50:50 epoxy blend also provides good resistance in both high and low pH environments.
[0029] The fiber is typically wet wound, however, a prepreg roving can also be used to form a matrix. A post cure process is preferable to achieve greater strength of the material. Typically, the post cure process is a two stage cure consisting of a gel period and a cross linking period using an anhydride hardener, as is commonly know in the art. Heat is added during the curing process to provide the appropriate reaction energy which drives the cross-linking of the matrix to completion. The composite may also be exposed to ultraviolet light or a high-intensity electron beam to provide the reaction energy to cure the composite material.
[0030] FIG. 2 is a partial cross section of a non-metallic element system 200 made of the composite, filament wound material described above. The element system 200 includes a sealing member 210 , a first and second cone 220 , 225 , a first and second expansion ring 230 , 235 , and a first and second support ring 240 , 245 disposed about a body 250 . The sealing member 210 is backed by the cones 220 , 225 . The expansion rings 230 , 235 are disposed about the body 250 between the cones 220 , 225 , and the support rings 240 , 245 , as shown in FIG. 2 .
[0031] FIG. 3 is an isometric view of the support ring 240 , 245 . As shown, the support ring 240 , 245 is an annular member having a first section 242 of a first diameter that steps up to a second section 244 of a second diameter. An interface or shoulder 246 is therefore formed between the two sections 242 , 244 . Equally spaced longitudinal cuts 247 are fabricated in the second section to create one or more fingers or wedges 248 there-between. The number of cuts 247 is determined by the size of the annulus to be sealed and the forces exerted on the support ring 240 , 245 .
[0032] Still referring to FIG. 3 , the wedges 248 are angled outwardly from a center line or axis of the support ring 240 , 245 at about 10 degrees to about 30 degrees. As will be explained below in more detail, the angled wedges 248 hinge radially outward as the support ring 240 , 245 moves axially across the outer surface of the expansion ring 230 , 235 . The wedges 248 then break or separate from the first section 242 , and are extended radially to contact an inner diameter of the surrounding tubular (not shown). This radial extension allows the entire outer surface area of the wedges 248 to contact the inner wall of the surrounding tubular. Therefore, a greater amount of frictional force is generated against the surrounding tubular. The extended wedges 248 thus generate a “brake” that prevents slippage of the element system 200 relative to the surrounding tubular.
[0033] Referring again to FIG. 2 , the expansion ring 230 , 235 may be manufactured from any flexible plastic, elastomeric, or resin material which flows at a predetermined temperature, such as Teflon® for example. The second section 244 of the support ring 240 , 245 is disposed about a first section of the expansion ring 230 , 235 . The first section of the expansion ring 230 , 235 is tapered corresponding to a complementary angle of the wedges 248 . A second section of the expansion ring 230 , 235 is also tapered to complement a sloped surface of the cone 220 , 225 . At high temperatures, the expansion ring 230 , 235 expands radially outward from the body 250 and flows across the outer surface of the body 250 . As will be explained below, the expansion ring 230 , 235 fills the voids created between the cuts 247 of the support ring 240 , 245 , thereby providing an effective seal.
[0034] The cone 220 , 225 is an annular member disposed about the body 250 adjacent each end of the sealing member 210 . The cone 220 , 225 has a tapered first section and a substantially flat second section. The second section of the cone 220 , 225 abuts the substantially flat end of the sealing member 210 . As will be explained in more detail below, the tapered first section urges the expansion ring 230 , 235 radially outward from the body 250 as the element system 200 is activated. As the expansion ring 230 , 235 progresses across the tapered first section and expands under high temperature and/or pressure conditions, the expansion ring 230 , 235 creates a collapse load on the cone 220 , 225 . This collapse load holds the cone 220 , 225 firmly against the body 250 and prevents axial slippage of the element system 200 components once the element system 200 has been activated in the wellbore. The collapse load also prevents the cones 220 , 225 and sealing member 210 from rotating during a subsequent mill up operation.
[0035] The sealing member 210 may have any number of configurations to effectively seal an annulus within the wellbore. For example, the sealing member 210 may include grooves, ridges, indentations, or protrusions designed to allow the sealing member 210 to conform to variations in the shape of the interior of a surrounding tubular (not shown). The sealing member 210 , however, should be capable of withstanding temperatures up to 450° F., and pressure differentials up to 15,000 psi.
[0036] In operation, opposing forces are exerted on the element system 200 which causes the malleable outer portions of the body 250 to compress and radially expand toward a surrounding tubular. A force in a first direction is exerted against a first surface of the support ring 240 . A force in a second direction is exerted against a first surface of the support ring 245 . The opposing forces cause the support rings 240 , 245 to move across the tapered first section of the expansion rings 230 , 235 . The first section of the support rings 240 , 245 expands radially from the mandrel 250 while the wedges 248 hinge radially toward the surrounding tubular. At a predetermined force, the wedges 248 will break away or separate from the first section 242 of the support rings 240 , 245 . The wedges 248 then extend radially outward to engage the surrounding tubular. The compressive force causes the expansion rings 230 , 235 to flow and expand as they are forced across the tapered section of the cones 220 , 225 . As the expansion rings 230 , 235 flow and expand, they fill the gaps or voids between the wedges 248 of the support rings 240 , 245 . The expansion of the expansion rings 230 , 235 also applies a collapse load through the cones 220 , 225 on the body 250 , which helps prevent slippage of the element system 200 once activated. The collapse load also prevents the cones 220 , 225 and sealing member 210 from rotating during the mill up operation which significantly reduces the required time to complete the mill up operation. The cones 220 , 225 then transfer the axial force to the sealing member 210 to compress and expand the sealing member 210 radially. The expanded sealing member 210 effectively seals or packs off an annulus formed between the body 250 and an inner diameter of a surrounding tubular.
[0037] The non-metallic element system 200 can be used on either a metal or more preferably, a non-metallic mandrel. The non-metallic element system 200 may also be used with a hollow or solid mandrel. For example, the non-metallic element system 200 can be used with a bridge plug or frac-plug to seal off a wellbore or the element system may be used with a packer to pack-off an annulus between two tubulars disposed in a wellbore. For simplicity and ease of description however, the non-metallic element system will now be described in reference to a frac-plug for sealing off a well bore.
[0038] FIG. 5 is a partial cross section of a frac-plug 300 having the non-metallic element system 200 described above. In addition to the non-metallic element system 200 , the frac-plug 300 includes a mandrel 301 , slips 310 , 315 , and cones 320 , 325 . The non-metallic element system 200 is disposed about the mandrel 301 between the cones 320 , 325 . The mandrel 301 is a tubular member having a ball 309 disposed therein to act as a check valve by allowing flow through the mandrel 301 in only a single axial direction.
[0039] The slips 310 , 315 are disposed about the mandrel 302 adjacent a first end of the cones 320 , 325 . Each slip 310 , 315 comprises a tapered inner surface conforming to the first end of the cone 320 , 325 . An outer surface of the slip 310 , 315 , preferably includes at least one outwardly extending serration or edged tooth, to engage an inner surface of a surrounding tubular (not shown) when the slip 310 , 315 is driven radially outward from the mandrel 301 due to the axial movement across the first end of the cones 320 , 325 thereunder.
[0040] The slip 310 , 315 is designed to fracture with radial stress. The slip 310 , 315 typically includes at least one recessed groove (not shown) milled therein to fracture under stress allowing the slip 310 , 315 to expand outwards to engage an inner surface of the surrounding tubular. For example, the slip 310 , 315 may include four sloped segments separated by equally spaced recessed grooves to contact the surrounding tubular, which become evenly distributed about the outer surface of the mandrel 301 .
[0041] The cone 320 , 325 is disposed about the mandrel 301 adjacent the non-metallic sealing system 200 and is secured to the mandrel 301 by a plurality of shearable members 330 such as screws or pins. The shearable members 330 may be fabricated from the same composite material as the non-metallic sealing system 200 , or the shearable members may be of a different kind of composite material or metal. The cone 320 , 325 has an undercut 322 machined in an inner surface thereof so that the cone 320 , 325 can be disposed about the first section 242 of the support ring 240 , 245 , and butt against the shoulder 246 of the support ring 240 , 245 .
[0042] As stated above, the cones 320 , 325 comprise a tapered first end which rests underneath the tapered inner surface of the slips 310 , 315 . The slips 310 , 315 travel about the tapered first end of the cones 320 , 325 , thereby expanding radially outward from the mandrel 301 to engage the inner surface of the surrounding tubular.
[0043] A setting ring 340 is disposed about the mandrel 301 adjacent a first end of the slip 310 . The setting ring 340 is an annular member having a first end that is a substantially flat surface. The first end serves as a shoulder which abuts a setting tool described below.
[0044] A support ring 350 is disposed about the mandrel 301 adjacent a first end of the setting ring 340 . A plurality of pins 345 secure the support ring 350 to the mandrel 301 . The support ring 350 is an annular member and has a smaller outer diameter than the setting ring 340 . The smaller outer diameter allows the support ring 350 to fit within the inner diameter of a setting tool so the setting tool can be mounted against the first end of the setting ring 340 .
[0045] The frac-plug 300 may be installed in a wellbore with some non-rigid system, such as electric wireline or coiled tubing. A setting tool, such as a Baker E-4 Wireline Setting Assembly commercially available from Baker Hughes, Inc., for example, connects to an upper portion of the mandrel 301 . Specifically, an outer movable portion of the setting tool is disposed about the outer diameter of the support ring 350 , abutting the first end of the setting ring 340 . An inner portion of the setting tool is fastened about the outer diameter of the support ring 350 . The setting tool and frac-plug 300 are then run into the well casing to the desired depth where the frac-plug 300 is to be installed.
[0046] To set or activate the frac-plug 300 , the mandrel 301 is held by the wireline, through the inner portion of the setting tool, as an axial force is applied through the outer movable portion of the setting tool to the setting ring 340 . The axial forces cause the outer portions of the frac-plug 300 to move axially relative to the mandrel 301 . FIGS. 6 and 6A show a section view of a frac-plug having a non-metallic sealing system of the present invention in a set position within a wellbore.
[0047] Referring to both FIGS. 6 and 6A , the force asserted against the setting ring 340 transmits force to the slips 310 , 315 and cones 320 , 325 . The slips 310 , 315 move up and across the tapered surface of the cones 320 , 325 and contact an inner surface of a surrounding tubular 700 . The axial and radial forces applied to slips 310 , 315 causes the recessed grooves to fracture into equal segments, permitting the serrations or teeth of the slips 310 , 315 to firmly engage the inner surface of the surrounding tubular.
[0048] Axial movement of the cones 320 , 325 transfers force to the support rings 240 , 245 . As explained above, the opposing forces cause the support rings 240 , 245 to move across the tapered first section of the expansion rings 230 , 235 . As the support rings 240 , 245 move axially, the first section of the support rings 240 , 245 expands radially from the mandrel 250 while the wedges 248 hinge radially toward the surrounding tubular. At a pre-determined force, the wedges 248 break away or separate from the first section 242 of the support rings 240 , 245 . The wedges 248 then extend radially outward to engage the surrounding tubular 700 . The compressive force causes the expansion rings 230 , 235 to flow and expand as they are forced across the tapered section of the cones 220 , 225 . As the expansion rings 230 , 235 flow and expand, the rings 230 , 235 fill the gaps or voids between the wedges 248 of the support rings 240 , 245 , as shown in FIG. 7 . FIG. 7 is a cross sectional view along lines B-B of FIG. 6 .
[0049] Referring again to FIGS. 6 and 6A , the growth of the expansion rings 230 , 235 applies a collapse load through the cones 220 , 225 on the mandrel 301 , which helps prevent slippage of the element system 200 once activated. The cones 220 , 225 then transfer the axial force to the sealing member 210 which is compressed and expanded radially to seal an annulus formed between the mandrel 301 and an inner diameter of the surrounding tubular 700 .
[0050] In addition to frac-plugs as described above, the non-metallic element system 200 described herein may also be used in conjunction with any other downhole tool used for sealing an annulus within a wellbore, such as bridge plugs or packers, for example. Moreover, while foregoing is directed to the preferred embodiment of the present invention, other and further embodiments of the invention may be devised without departing from the basic scope thereof, and the scope thereof is determined by the claims that follow. | A non-metallic element system is provided as part of a downhole tool that can effectively seal or pack-off an annulus under elevated temperatures. The element system can also resist high differential pressures without sacrificing performance or suffering mechanical degradation, and is considerably faster to drill-up than a conventional element system. In one aspect, the composite material comprises an epoxy blend reinforced with glass fibers stacked layer upon layer at about 30 to about 70 degrees. In another aspect, a mandrel is formed of a non-metallic polymeric composite material. A downhole tool, such as a bridge plug, frac-plug, or packer, is also provided. The tool comprises a support ring having one or more wedges, an expansion ring, and a sealing member positioned with the expansion ring. | 4 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] Continuation of U.S. patent application Ser. No. 12/786,456 filed on May 25, 2010 and incorporated herein by reference in its entirety.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0002] Not applicable.
BACKGROUND
[0003] This disclosure relates generally to the field of drilling wellbores through subsurface rock formations. More particularly, the disclosure relates to method for removing fluid that has entered the wellbore from subsurface formations outside the wellbore.
[0004] Drilling wellbores through subsurface rock formations includes inserting a drill string into the wellbore. The drill string, which is typically assembled by segments (“joints” or “stands”) of pipe threadedly coupled end to end) has a bit at its lower end. The drill string is suspended in a hoist unit that forms part of a drilling “rig.” During drilling, a specialized fluid (“mud”) is pumped from a tank into a passage in the interior of the drill string and is discharged through courses or nozzles on the bit. The mud cools and lubricates the bit and lifts drill cuttings to the surface for treatment and disposal. The mud also typically includes high density particles such as barite (barium sulfate), hematite (iron oxide), or other weighting agents suspended therein to cause the mud to have a selected density. The density is selected to provide sufficient hydrostatic pressure in the wellbore to prevent fluid in the pore spaces of the rock formations from entering the wellbore. The density is also selected to maintain mechanical integrity of the wellbore.
[0005] Wellbores drilled through subsurface formations below the bottom of a body of water, particularly if the water is very deep (e.g., on the order of 1,000-3,000 meters or more) may require special equipment for effective drilling. An example drilling system for such water depths is shown in FIG. 1 . The drill string 28 extends from a drilling rig (not shown for clarity) and is disposed in a wellbore 14 being drilled through rock formations 12 below the bottom of a body of water 10 such as a lake or the ocean. A wellhead 16 including a plurality of sealing devices collectively called a “BOP stack” is disposed at the top end of a surface casing 14 A cemented in place to a relatively shallow depth below the mud line. A marine riser 26 extends from the upper part of the wellhead 20 to the drilling rig (not shown). The riser 26 usually has auxiliary lines associated with it known as “choke” lines 24 , and a “kill line” 22 . Fluid may be pumped into such lines from the rig (not shown) toward the wellbore 14 or may be allowed to move from the wellbore 14 toward the surface. Valves 18 , 20 control fluid movement at the lower end of the kill line 22 . Corresponding valves 30 , 32 control fluid movement at the lower end of the choke line 24 .
[0006] In the present example, the riser 26 is hydraulically opened to the wellbore 14 below. In order to maintain a hydrostatic pressure in the wellbore annulus 13 that is lower than would be provided if the entire length of the riser 26 were filled with mud, the riser 26 may be partially or totally filled with sea water. See, for example, U.S. Pat. No. 6,454,022 issued to Sangesland et al. As the mud leaves the wellbore annulus 13 (the space between the drill string and the wellbore wall), it is diverted, through suitable valves 34 , 36 to a pump 38 that lifts the mud to the surface through a separate mud return line 40 . Typically, the pump 38 is operated so that the interface between the drilling mud and the water column above in the riser 26 is maintained at a selected level. Maintaining the selected level causes a selected hydrostatic pressure to be maintained in the wellbore 14 .
[0007] The issue dealt with by methods according to the present invention is to safely remove from the wellbore 14 any fluid which enters from the rock formations 12 . Such fluid, by reason of its entry, is at a higher pressure than the total hydrostatic pressure exerted by the mud column in the annulus 13 and the column of sea water in the riser 26 . Methods known in the art for dealing with such fluid entry require “shutting in the well”, meaning that the BOP stack is closed to seal against the drill string 28 , and fluid pumping is stopped. Frequently during such operation, the density of the drilling fluid will be increased by adding more dense, powdered material to the mud. See for example U.S. Pat. No. 6,474,422 issued to Schubert et al. for an example of a kick control method.
[0008] It is also possible that the pressures necessary to be applied to the mud return pump and its connecting lines may be exceeded if conventional kick control methods are used.
[0009] It is desirable to have a method for removing kick fluid from a wellbore that does not require the kick fluid to go through the pump, but maintains well bore pressures at acceptable levels. These pressures must be high enough to keep additional formation fluids from entering the wellbore from one formation, while not exceeding the fracture pressure (pressure that cases wellbore fluids to enter the formation) of other exposed formations, most specifically the formation at the last casing shoe, which is the end of the last installed casing.
SUMMARY
[0010] One aspect of the disclosure is a method for removing a fluid influx from a wellbore. The wellbore is drilled using a drill string having an internal passage therethrough. The wellbore has a wellhead disposed proximate a bottom of a body of water disposed thereabove. A fluid outlet of the wellbore is coupled to an inlet of a mud return pump. An outlet of the return pump is coupled to a return line to the water surface. A riser is disposed above the wellhead and extends to the water surface. The riser is substantially or partially filled with a fluid less dense than a fluid pumped through the drill string. The method includes detecting the influx when a rate of the return pump increases. Flow out from the well is diverted from the return pump inlet to a choke line when the influx reaches the wellhead. A choke in the choke line is operated so that a substantially constant bottom hole pressure is maintained while drilling fluid continues to be pumped through the drill string. Fluid flow from the well is rediverted to the return pump inlet when the influx has substantially left the wellbore.
[0011] In one example, an interface level in the riser between the less dense fluid and the fluid pumped through the drill string is then increased to increase fluid pressure at the bottom of the well. A method according to one aspect of the invention for removing a fluid influx from a subsea drilling wellbore drilled using a pump to return drilling fluid from the wellbore to the sea surface. The fluid influx is observed when an operating rate of the return pump increases. Drilling fluid continues to be pumped through the drill string and the return pump until the fluid influx reaches the wellhead. The return pumping is performed at a rate such that a flow into the wellbore substantially equals a flow out of the wellbore. An intake to the return pump is hydraulically isolated from the wellbore. Flow out of the wellbore is diverted to a choke line. The choke is operated so that the flow into the wellbore substantially equals a flow out of the wellbore. Flow out of the wellbore back to the intake of the return pump when an end of the influx reaches the wellhead. The less dense fluid is pumped down an auxiliary line proximate a bottom end thereof to proximate a bottom end of the choke line. Influx fluid is displaced from the choke line using the less dense fluid.
[0012] In one example, drilling fluid is pumped down the auxiliary line into a lower end of the riser to raise an interface level between drilling fluid and less dense fluid in a riser above the wellhead such that a fluid pressure at the bottom of the well is at least as much as fluid pressure in rock formations penetrated by the wellbore.
[0013] Other aspects and advantages of the invention will be apparent from the following description and the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] FIG. 1 is an example prior art mud lift drilling system.
[0015] FIGS. 2-15 show various elements of a method according to the invention that can be performed using the system shown in FIG. 1 . In the various figures, like components will be identified using like reference numerals.
DETAILED DESCRIPTION
[0016] A well control procedure described herein will enable circulating out a fluid influx (“kick”) from a rock formation when drilling in dual gradient mode through a line auxiliary to a drilling riser, such as a choke line. The procedure is dynamic and never exposes the wellbore to a complete column of drilling mud from the bottom of the well to the surface (in the riser). Such a mud column could exert enough hydrostatic pressure to fracture the formations exposed by the wellbore.
[0017] FIG. 1 , as explained in the Background section herein, represents drilling under normal conditions, wherein no fluid enters the wellbore from any formation exposed by the wellbore. When drilling is under normal conditions, the drilling system may be configured as shown in FIG. 1 , specifically, the riser 26 and choke and kill (“C&K”) lines are filled with seawater. The C&K lines are isolated from the wellbore 14 by keeping its lower control valves 18 , 20 , 30 , 32 closed. The pump inlet valves 34 , 36 are open and the pump 38 is operated to lift drilling mud to the surface. A pump suction pressure sensor SPP measures annulus discharge pressure, typically proximate the intake of the pump 38 . The pressure sensor SPP as well as other pressure sensors described below may be coupled to a controller (not shown) for automatic or semi-automatic control over various components of the system. Alternatively, measurements made by the sensors may be communicated to the system operator for manual operation. Operation of the pump 38 is typically maintained automatically at a set point pressure as measured by the sensor SPP, which operation keeps the mud/seawater interface in the riser 26 at a constant level. The riser 26 is open to wellbore 14 as explained in the Background section herein, and includes sea water therein above the interface. The sea water may extend all the way to the surface or to a selected depth below the surface.
[0018] FIG. 2 shows an example ten barrel volume fluid influx (“kick”) 50 entering the wellbore. Such a kick fills about 100 meters of the wellbore with kick fluid, although the length of the wellbore filled by any particular kick will depend, as is known in the art, on the actual volume of the kick, the diameter of the drill string and the diameter of the wellbore. It can be observed that the pump 38 speed and horsepower output will increase in response in order to move the extra fluid volume resulting from the fluid influx (kick). The system operator may determine from observation of the pump speed and/or power measured by sensors that a kick has entered the well. Generally, the pump speed and/or power measurement increases due to the kick 50 because the pump 38 response to the extra fluid volume. As the kick enters the wellbore it may cause movement of the mud/seawater interface in the riser upward; this will have the effect of increasing the SPP reading (more mud, less water in the riser). However, the control program, having sensed this increase in pressure will speed the pump 38 up and restore the level to what is was (the level only changes an inch or two) prior to the kick, This will then restore SPP back to what it was. Once it is observed that a kick is occurring from the change in pump speed and/or power the SPP setpoint may be changed to increase pressure. This has the effect of slowing the pump 38 so that it supports less of the column of fluid in the mud return line adding pressure to the bottom the well and killing the kick. It should be understood that observing the increase in pump speed is only one technique for observing an influx. It is also possible to include a flow meter at a selected position in the mud return line and observe an increase in flow rate. Other techniques for observing the influx will occur to those skilled in the art.
[0019] FIG. 3 shows an initial action in controlling and circulating out the kick 50 . An annular preventer (not shown separately) in the BOP stack 16 is closed around the drill string, thereby isolating the wellbore 14 from the riser 26 . The suction set point pressure may be increased to control the kick 50 . This can be performed by slowing the operating rate of the pump 38 . The pump rate is slowed, and the suction pressure (as measured by the sensor SPP) is increased until the flow rate of mud into well (“flow in”—pumped through the drill string 28 and the rate of flow out of well (“flow out”—through the return line 40 ) are substantially equal. When the flow in and the flow out are substantially equal, no additional fluid is entering well. At such condition, the kick 50 has been stopped or “killed.” It is then necessary to circulate the kick fluid out of the wellbore 14 in a controlled manner. Kick fluid frequently contains gas, in solution and/or as actual bubbles. As the kick fluid moves toward the surface, and hydrostatic pressure is reduced, the gas exsolves from the kick fluid and/or expands in volume. When the flow rates in and out are balanced, the drill string pressure increases, which may be observed by measurements made using a drill string pressure sensor DPP.
[0020] FIG. 4 shows the situation where the rig mud pump (the pump that moves mud through the interior of the drill string) rate is slowed, but the rate is sufficient to keep the drill string full of mud. The kick fluid begins moving up wellbore annulus 13 . At this point, the mud return pump 38 is operated so that the intake pressure (measured by the sensor SPP) is increased to maintain a constant drill pipe pressure (as measured by sensor DPP). The mud return pump 38 should be operated to maintain fluid flow out equal to fluid flow in.
[0021] FIG. 5 shows the kick fluid moving up the wellbore and beginning to expand in volume. During such time, the operator continues to control the mud return pump 38 speed so to maintain constant drill string pressure (measured by sensor DPP) and to cause flow out to be substantially equal to flow in.
[0022] FIG. 6 shows continuing to adjust the mud return pump 38 speed to keep constant drill string pressure. The mud return pump 38 speed is also controlled to maintain flow out matching flow in. At the point shown in FIG. 6 , the kick fluid 50 has reached the BOP stack 16 .
[0023] FIG. 7 shows opening the valves 30 , 32 to the choke line 24 . A variable orifice choke 44 coupled to the surface end of the choke line 24 is operated to maintain fluid pressure at the bottom of the wellbore (bottom hole pressure) substantially constant. Bottom hole pressure may be measured by a sensor (not shown) in the drill string, or may be estimated using the density of the drilling mud, and an hydraulic model that describes the flow system including the drill bit, wellbore walls, drill string and rheological properties of the mud.
[0024] When the valves 30 , 32 to the choke line 24 are opened, the valves 34 , 36 to the intake side of the mud return pump 38 are closed. Thus, further flow out of the wellbore 14 will move up the choke line 24 . When the pump intake valves 34 , 36 are closed, the mud return pump 38 is stopped. It may be necessary that the flow rate into the well will have to be reduced to avoid excess pressure from friction of the fluid in the smaller choke line 24 .
[0025] FIG. 8 shows that the kick fluid 50 is less dense than the mud and seawater, and thus displaces the sea water in the choke line 24 . The surface choke 44 continues to be operated to keep the bottom hole pressure substantially constant. Note that the foregoing is correct for water based drilling fluid. If oil based drilling fluid is used, the oil based fluid will be very close to its original density because any gas will be dissolved in the oil based fluid. Reduction of fluid density will not occur until exsolution of the gas. When this actually takes place varies depending on wellbore conditions.
[0026] FIG. 9 shows that while the kick volume at the bottom of the wellbore was ten barrels, the kick will expand substantially as the kick moves up the choke line 24 to the surface. The choke line 24 unit volume in the present example 0.0197 bbl/ft. Thus, in a system in 10,000 feet water depth, the total choke line volume is 197 barrels.
[0027] FIG. 10 shows the surface choke 44 being operated to keep bottom hole pressure constant as the kick fluid is discharged through the choke 44 . A typical indication that bottom hole pressure is constant is a constant drill string pressure (as shown by sensor DPP).
[0028] FIG. 11 shows restarting the mud return pump 38 . The valves 34 , 36 to the mud return pump 38 inlet are opened, and the valves 30 , 32 to the choke line 24 are also open. The intake pressure set point on the mud return pump 38 , measured by sensor SPP, is set to match the existing pressure at the mud return pump 38 intake The valves 30 , 32 to the choke line 24 are then closed.
[0029] FIG. 12 shows connecting one of the other auxiliary lines, e.g., the kill line 22 to the choke line 24 using bypass lines or internal passages the BOP stack 16 . The valves 30 , 32 at the base of the choke line and the kill line 18 , 20 are then opened. Sea water is pumped from the surface down the kill line 22 , back up the choke line 24 . Such pumping displaces the kick fluid 50 from the choke line 24 .
[0030] FIG. 13 shows that once kick fluid 50 is fully displaced from the choke line 24 , the well choke pressure (which may be measured by sensor CK) is zero. At this point any connection between the boost line 22 and the choke line 24 may be removed or closed. The wellbore 24 is then returned to regular drilling control by the following procedure, which takes into account the higher fluid pressure in the rock formation from which the kick originated.
[0031] FIG. 14 shows pumping mud through the boost line (not shown). The boost line is placed in hydraulic communication with the lower end of the riser 26 . Pumping continues down the boost line until the fluid pressure at the bottom of the riser 26 equals the pressure in the wellbore existing at the BOP stack 16 . This pressure is the existing pressure (measured by the sensor SPP) at the mud return pump 38 intake.
[0032] FIG. 15 shows the annular preventer being opened, the choke line 24 valves 30 , 32 and the kill line 22 valves 18 , 20 being closed, and normal drilling resuming with a new fluid level interface in the riser 26 . The new fluid interface level in the riser 26 , being higher than the interface level shown in FIG. 1 , provides a greater bottom hole pressure than with the interface as shown in FIG. 1 . Thus, formations having higher fluid pressure may be safely drilled without fluid entry into the wellbore 14 .
[0033] It will be appreciated by those skilled in the art that the foregoing method may also be used when no riser connects the wellhead to the drilling unit. In such examples, the wellhead may have affixed to the top thereof a rotating diverter, rotating BOP or rotating control head that directs fluid from the annular space surrounding the drill string 28 to the pump 38 intake. The intake pressure of the pump SPP will be adjusted for the lack of a column of liquid applied to the wellbore annulus in “riserless” configurations. The principle of operation of the method is substantially the same for the riser version shown and explained with reference to the figures as it is in riserless configurations.
[0034] A method according to the invention may enable safe control of fluid influx into a wellbore being drilled without the need to shut in the wellbore and without the need to increase the density of drilling mud to prevent further fluid influx.
[0035] While the invention has been described with respect to a limited number of embodiments, those skilled in the art, having benefit of this disclosure, will appreciate that other embodiments can be devised which do not depart from the scope of the invention as disclosed herein. Accordingly, the scope of the invention should be limited only by the attached claims. | A method for removing a fluid influx from a subsea wellbore drilled using a pump to return fluid from the wellbore to the surface. The method includes detecting the influx when a rate of the return pump increases. Flow from the wellbore is diverted from the return pump to a choke line when the influx reaches the wellhead. A choke in the choke line is operated so that a substantially constant bottom hold pressure is maintained while drilling fluid continues to be pumped through the drill sgring. Fluid flow from the wellbore is redirected to the return pump inlet when the influx has substantially left the well. | 4 |
FIELD OF THE INVENTION
The invention relates to the positioning and operation of controller towers for backhoes. More specifically, it relates to a method, system and apparatus for safely and securely positioning controller towers to allow the operator to easily and conveniently move the traditional swivel seat often associated with backhoe cabs into and out of the backhoe operating position.
BACKGROUND OF THE INVENTION
Backhoes are often equipped with an operator station having a dual position swivel seat which allows the operator to remain seated as he/she pivots between loader and backhoe operations. Such a provision normally requires movable controller towers as controller towers that are properly located for optimum operator convenience and comfort in backhoe operation usually interfere with the operator's legs and/or with the seat as the operator pivots between backhoe and loader functions. The movable controller towers usually have two basic positions: (1) the stow position which allows the operator to move the swivel seat into and out of the backhoe operating position; and (2) the backhoe operating position which allows the operator to comfortably operate the backhoe when the swivel seat is in the backhoe operating position.
Conventional movable controller towers are mounted such that one controller tower is located on each side of the seat, each controller tower being secured in either of the two basic positions via releasable cable and latch mechanisms.
SUMMARY OF THE INVENTION
The inventors recognize that conventional movable controller towers require a significant amount of extra hardware for cable and latch mechanisms as well as extra labor to produce and assemble the hardware. Further, the additional hardware occupies precious portions of limited available space that could be used for other valuable purposes. Finally, the transverse shaft, commonly shared by both controller towers in some conventional systems, is exposed to the detriments of the environment as it is located under the cab floor; it also reduces functionality in the system by requiring simultaneous movement of the towers.
The invention overcomes each of the above mentioned limitations of conventional controller towers via an elegantly simple mechanism. Simple mounting brackets are fixedly attached to portions of the frame or floor on either side of the seat. A shaft, some ball bearings and a snap ring secure each tower to the mounting brackets via a hole in the brackets and serve as a pivot for the independent movement of each tower to each of its positions. A gas filled strut, operatively attached to each tower and corresponding mounting bracket, provides a toggle or over-center effect as each tower is moved from one of its two positions to the other. Thus, an operator may change the position of a tower by pushing or pulling a portion of the tower structure. Adequate extending forces of each strut keeps each of the towers in either of their dual positions, thus eliminating the need for cables and latches to lock the towers. The common rotational shaft, present in some conventional systems, is also eliminated, increasing available space on the underside of the floor for greater access to other components. Finally, the time and cost for parts and labor for each controller tower are reduced.
BRIEF DESCRIPTION OF THE DRAWINGS
Embodiments of the invention will be described in detail, with references to the following figures, wherein:
FIG. 1 is a view of a work vehicle in which the invention may be used;
FIG. 2 is a side view of the invention in an operating position;
FIG. 3 is a side view of the invention in a stow position, i.e., the invention is positioned to allow a change in seat position;
FIG. 4 is an oblique view of the invention; and
FIG. 5 is an exploded view of the invention.
DETAILED DESCRIPTION
FIG. 1 illustrates a work vehicle 10 in which the invention may be used. The particular work vehicle illustrated in FIG. 1 is a loader backhoe with a single multiple position swivel seat 20 . The multiple positions of the swivel seat 20 include at least a loader operating position and a backhoe operating position and are usually angularly spaced 180° apart. In FIG. 1 , the swivel seat 20 is shown in the loader operating position. The work vehicle also has two backhoe control assemblies 100 .
FIG. 2 illustrates an exemplary embodiment of a backhoe control assembly 100 in the backhoe operating position according to the invention. FIG. 3 shows the same backhoe control assembly 100 in the stow position. The particular control assembly 100 illustrated is located on the left side of the seat when the seat is in the backhoe operating position. Only this control assembly 100 will be described as its working parts are identical to those of the other control assembly (not shown) on the left side of the seat. The control assembly 100 includes a mounting bracket 110 , a strut assembly 120 operatively attached to the mounting bracket, a movable controller tower 130 operatively attached to the mounting bracket 110 and the strut assembly 120 , a pilot controller assembly 160 and an armrest assembly 140 .
The mounting bracket 110 includes a first mounting side 110 a containing mounting holes 110 d and 110 e ; a second mounting side 110 b containing mounting holes 110 f and 110 g ; and center portion 110 h , including two controller tower stop assemblies 114 and 115 , a hole 112 for attaching the strut assembly 120 to the mounting bracket 110 , and a race 110 c for pivotally attaching the controller tower 130 to the mounting bracket 110 . The mounting bracket 110 is securely attached to left frame members 170 and 171 as well as the cab floor 180 via mounting holes 110 d , 110 e , 110 f and 110 g by means well known in the art. See FIG. 3 for one exemplary method of attachment in which the mounting bracket 110 is attached to right frame members 170 and 171 via bolts 171 a and nuts 171 b and to the floor via bolt 180 a , nut 180 b and via a tab 181 welded to the mounting bracket 110 . Each of the stops 114 and 115 include a bolt 111 a , a spacer 11 b and a nut 111 c.
The strut assembly 120 includes a conventional gas filled strut 121 having a first end 121 a and a second end 121 b . The first and second ends 121 a , 121 b are constructed for attachment to working structures in manners well known in the art via eyelets 122 , each eyelet having three dimensional rotation characteristics.
The movable controller tower 130 includes a mounting plate 131 having two square positioning holes 133 for positioning a first stiffening rib 137 a and a square hole 136 for positioning rotationally fixed screw 126 . Attached to the mounting plate, via welding are a hose harness 137 a , a second stiffening rib 137 b , a third stiffening rib 137 c , a pivot shaft 134 and a controller cage 150 . The stiffening ribs 137 a , 137 b and 137 c are positioned as shown in FIGS. 1 , 2 , 3 , and 4 and welded to the mounting plate by means well known in the art. The controller cage 150 houses the pilot controller assembly 160 and restricts/constrains all movement of the pilot controller assembly 160 as a whole via methods and structures well known in the art.
The armrest assembly 140 includes a strong and rigid support arm 142 having a pivot hole 144 and an adjustment hole 143 . The support arm 142 may be constructed of a metal such as steel. The armrest assembly 140 also includes a soft surface mounted to the support arm 142 . The soft surface may be provided by a padded roller 141 rotationally mounted to the support arm 142 as in the embodiment described and illustrated herein (see FIG. 4 ) or a conventional soft surface mounted via a suitable means already known in the art. The support arm 142 is pivotally mounted to the controller cage via a bolt 146 , a spacer 148 , the pivot hole 151 a in a side plate 151 of the controller cage 150 and a nut (not shown). The armrest 140 is rotationally constrained by a screw 149 , a slotted hole 144 and a nut arm 145 . The armrest 140 may be rigidly held in place and prevented from rotating about bolt 146 by sufficiently tightening the nut arm 145 . Additionally, the rotational position of the support arm 142 may be adjusted along the length of the adjustment hole 143 by loosening the nut arm 145 sufficiently to allow movement.
The mounting plate 131 is operatively attached to the first end 121 a of the gas filled strut 121 via the square hole 136 , the screw 126 , the spacer 129 , the eyelet 122 a , a spacer 123 and the nut 124 . The second end 121 b of the gas filled strut 121 is attached to the mounting bracket 110 via nut 124 , bolt 125 , hole 112 , eyelet 122 b and three spacers 123 , 123 , 123 as shown in FIG. 4 . Thus, the movable controller tower 130 is operatively connected to the mounting bracket 110 via the gas filled strut 120 .
The mounting plate is rotationally attached to the mounting bracket 110 via the pivot shaft 134 , ball bearings 191 , 192 , a spacer 193 , a snap ring 194 and the race 110 c . During assembly of the mounting plate 131 to the mounting bracket 110 , ball bearings 191 and 192 press fit into the hole provided by the race 110 c . The pivot shaft 134 is then slip fitted into the ball bearings 191 and 192 , the spacer 193 is fitted over the pivot shaft 134 and, finally, the snap ring 194 is assembled to the pivot shaft 134 via shaft groove 135 . Thus, movement of the mounting plate 131 at the pivot shaft 134 is constrained by the mounting bracket 110 in all directions excepting a rotational motion about an axis of the pivot shaft 134 .
The gas filled strut 120 is compressive and is assembled to the controller tower 130 and the mounting bracket 110 such that it is shortest at an intermediate position between the stow and backhoe operating positions of the controller tower 130 (see FIGS. 2 and 3 ). Thus, the gas filled strut 120 acts as a toggle mechanism which resists motion of the controller tower 130 from a first or a second position toward the intermediate position and enhances motion of the controller tower 130 from the intermediate position toward the first or the second position. Although the load applied by the gas filled strut 120 increases with decreases in its overall length, the portion of the load applied to resist movement of the controller tower 130 decreases as the angle of the strut axis approaches 90° with respect to the mounting bracket base 113 . As a result of this arrangement, resistance to any motion of the controller tower 130 toward the intermediate position is highest at the stow and backhoe operating positions. Resistance to movement of the controller tower 130 toward the intermediate position tends to decrease as the distance between the position of the controller tower 130 and the intermediate position decreases. The gas filled strut 120 acts to push the controller tower 130 away from the intermediate position with a force that is proportional to the distance of the controller tower 130 from the intermediate position.
Resistance to movement from the stow position or the backhoe operating position is sufficient to keep the controller tower 130 in that position. The application force required to overcome the resistance may be preset at a minimum of, for example, 20 pounds.
The stops 114 and 115 define each of the rotational limits for movement, i.e., the stow position and the operating position, respectively, for the controller tower 130 . In the stow position, surface 131 a contacts the stop 114 and prevents further movement of the controller tower 130 away from the intermediate position. In the operating position, the surface 131 b contacts the stop 115 preventing further movement of the controller tower 130 away from the intermediate position.
Having described the illustrated embodiment, it will become apparent that various modifications can be made without departing from the scope of the invention as defined in the accompanying claims. | A controller tower positioning system for a work vehicle for securing the controller tower to one of at least two positions. The system employs a mounting bracket fixed to the floor or a frame member of the work vehicle, a movable controller tower rotatably mounted to the mounting bracket and a resistive element strategically mounted to the controller tower and the mounting bracket to provide resistance to movement away from either of the two positions and a toggle effect as the controller tower is moved from one of the two positions to the other. The controller assembly is physically restrained at the free end of the controller tower. | 4 |
CROSS REFERENCE TO RELATED APPLICATION
[0001] This application claims priority to U.S. patent application Ser. No. 62/011,375, entitled “INLINE APPARATUS CAPABLE OF ACCEPTING A THREADED CONNECTION AT ITS BASE,” and filed on Jun. 12, 2014, the entire contents of which are incorporated herein in their entirety as if set forth in full.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] This invention relates to the field of heating, ventilating and air conditioning (HVAC) systems and, more particularly, to devices that treat airflow through the ductwork, hoses or the like of HVAC systems.
[0004] 2. Description of Related Art
[0005] It is common to employ one or more devices in homes, buildings, and other enclosed spaces to treat the air being inhaled by inhabitants in various manners. As one example, various types of odor management (e.g., neutralizing or elimination) systems have been utilized in which an air flow is moved past a product which may be vaporized, either by evaporation or sublimation, in order to distribute the vaporized product throughout the surrounding environment to neutralize, treat, purify and/or freshen the air and/or the like. For instance, some odor management systems are installed “inline” in the ductwork or hosing of an HVAC system so that activation of the HVAC system (e.g., including triggering of the blower fan in the HVAC system) simultaneously initiates activation of the odor neutralizing or elimination system.
SUMMARY OF THE INVENTION
[0006] Existing inline ductwork odor management systems are generally expensive to install, are prone to maintenance that requires expensive replacement parts, and inefficiently treat the air leading to sub-optimal levels of odor neutralization and/or elimination. For instance, some existing odor management devices (e.g., including odor neutralizing agents) are physically placed across the airflow path of the ductwork which necessarily obstructs the airflow and increases the power demands of the blowing componentry. Oftentimes, disassembly of these devices is required which adds wear to system components, adds weight if being suspended in the air for mounting purposes and can result in undesirable air being present where the disassembly occurs. Physical obstruction of the airflow and/or sagging of the ductwork due to the suspended componentry ultimately leads to inefficient airflow, unneeded recurring labor, and increased maintenance costs.
[0007] As another example, some odor management devices require supplemental electrical components and power to operate (e.g., independent of that of an HVAC system), such as electrically powered dispensing agent. However, some of these agents can break down causing particles to travel throughout an HVAC system leading to an increased risk of damage to downstream ventilation components as well as fire hazards. Furthermore, supplement power requirements increase overall energy consumption by the home, building, etc.
[0008] In this regard, disclosed herein is an airflow treatment device configured to be installed inline in the ductwork of an air handling system (e.g., HVAC system) in a manner that is substantially free of obstructing the airflow through the ductwork or requiring any supplemental power to treat the airflow passing by the treatment device. The disclosed airflow treatment device can also be maintained substantially free of any interruptions, disassembly or downtime to the air handling system after initial inline installation of the disclosed device. Broadly, the disclosed airflow treatment device includes an airflow passageway including first and second opposite openings that may be installed inline in the existing ductwork of an air handling system (e.g., vertically, horizontally, etc.) to treat air entering a building or home or exiting a building or home as well as an air treatment passageway that provides access to the airflow passageway.
[0009] As just one example, an existing duct of an air handling system may be appropriately separated (e.g., split, cut, etc.) into first and second duct members having respective open ends. The respective open ends of the first and second duct members may then be appropriately secured (e.g., with hose clamps or the like) over the first and second openings of the airflow treatment device so that the airflow passageway extends through the first duct member, the first and second openings of the device, and the second duct member. In one arrangement, the airflow treatment device may be appropriately hung from or otherwise secured to a fixed member (e.g., structural member of the house or building, such as a joist, etc.) at a point above the first and second duct members to limit or otherwise reduce the load placed on the ductwork by the airflow treatment device. As just one example, the airflow treatment device may have a first connector member (e.g., hole, hook, opening, etc.) that is configured to connect with a corresponding second connector member (e.g., hook, hole, etc.) on a joist or other fixed member of the house or building.
[0010] The airflow treatment device also includes an air treatment passageway including a first opening over which an air treatment container (e.g., jar, bottle, etc.) may be appropriately releasably secured and an opposite second opening that intersects or otherwise feeds into the airflow passageway. For instance, the airflow treatment device may have a threaded member adjacent or about the first opening of the air treatment passageway onto which an opening of the air treatment container may be threaded. The air treatment container may have any appropriate air treatment or odor neutralizing substance or agent therein (e.g., including one or more essential oils, etc.) to appropriately treat the airflow through the airflow passageway. When the air treatment substance needs to be replenished, the air treatment container may be appropriately disconnected (e.g., unscrewed) from the airflow treatment device and the air treatment substance may be replenished before re-securing the air treatment container to the airflow treatment device. The air treatment container may be secured to and removed from the airflow treatment device free of disconnecting the airflow treatment device from the first and second duct members or otherwise disrupting the air handling system. In one embodiment, an adapter or coupling member may be used to interconnect the air treatment container to the airflow treatment device, such as when the air treatment container is not configured to be directly interconnectable to the airflow treatment device.
[0011] In one aspect, a kit for use in treating airflow in ductwork includes a one-piece body having first and second openings that define an airflow passageway therebetween and a third opening between the first and second openings that provides access to the airflow passageway; and an air treatment container that is one of releaseably securable or releasably secured to the body over the third opening, where the air treatment container includes an air treatment substance therein to treat airflow through the airflow passageway.
[0012] For instance, the body may include a first threaded member adjacent the third opening, where the air treatment container includes a second threaded member that is threadably engageable with the first threaded member to releasably secure the air treatment container to the body. In one arrangement, a screening element may be disposed over the third opening to limit particulates or the like of the odor or air treatment substance from entering the airflow passageway.
[0013] In another aspect, a kit for use in treating airflow in ductwork includes an airflow treatment device including a first body having a first wall that defines an airflow passageway and a second body having a second wall that defines a first portion of an air treatment passageway that intersects the airflow passageway. The first wall includes first and second opposite open ends, where the airflow passageway extends between the first and second opposite open ends of the first wall. The second wall includes first and second opposite open ends, where the first portion of the air treatment passageway extends between the first and second opposite open ends of the second wall, and where the first open end of the second wall is disposed outside of the airflow passageway. The disclosed kit also includes an air treatment container that is one of releaseably securable or releasably secured to the first open end of the second wall. The air treatment container includes a third body having a third wall that defines a second portion of the air treatment passageway that feeds into the first portion of the air treatment passageway, where the third wall includes a closed first end and an opposite open second end, and where the second portion of the air treatment passageway extends between the closed first end and the opposite open second end of the third wall.
[0014] In one arrangement, the device includes a first releasable interconnection apparatus and the airflow treatment container includes a second releasable interconnection apparatus that is complimentary to the first releasable interconnection apparatus. For instance, the first releasable interconnection apparatus may be a first set of threads and the second releasable interconnection apparatus may be a second set of threads that is threadably engageable with the first set of threads. In one arrangement, the first releasable interconnection apparatus may be disposed on one of the inside or the outside of the second wall and the second releasable interconnection apparatus may be disposed on the other of the inside or the outside of the third wall.
[0015] In one arrangement, a system includes the kit, an open end of a first duct secured over the first open end of the first body, and an open end of a second duct secured over the second open end of the first body, where the airflow passageway is defined through the first duct, the first body, and the second duct.
[0016] In one arrangement, a method includes securing an open end of a first duct member over the first open end of the first body of the kit and securing an open end of a second duct member over the second open end of the first body of the kit, wherein the airflow passageway is defined through the first duct, the first body, and the second duct.
[0017] In addition to the exemplary aspects and embodiments described above, further aspects and embodiments will become apparent by reference to the drawings and by study of the following descriptions.
DESCRIPTION OF THE DRAWINGS
[0018] FIG. 1 is a perspective view of an airflow treatment device that is configured to treat air in an air handling system.
[0019] FIG. 2 is another perspective view of the airflow treatment device of FIG. 1 .
[0020] FIG. 3 is another perspective view of the airflow treatment device of FIG. 1 .
[0021] FIG. 4 is a front elevation view of the airflow treatment device of FIG. 1 .
[0022] FIG. 5 is a side elevation view of the airflow treatment device of FIG. 1 .
[0023] FIG. 6 is a top view of the airflow treatment device of FIG. 1 .
[0024] FIG. 7 is a bottom view of the airflow treatment device of FIG. 1 .
[0025] FIG. 8 is a front exploded view of the airflow treatment device of FIG. 1 , an airflow treatment container, first and second duct members, and first and second securement devices for securing the first and second duct members to the airflow treatment device.
[0026] FIG. 9 is similar to FIG. 8 but with the first and second duct members being secured to the airflow treatment device with the first and second securement devices and the airflow treatment container being secured to the airflow treatment device.
[0027] FIG. 10 is an exploded perspective view of another embodiment of the airflow treatment device, an airflow treatment container, an adapter for connecting the airflow treatment container to the airflow treatment device, and first and second securement devices for securing first and second duct members to the airflow treatment device.
[0028] FIG. 11 is a perspective view of the adapter of FIG. 10 .
[0029] FIG. 12 is a perspective view of another embodiment of the airflow treatment device.
[0030] FIG. 13 is a side view of the airflow treatment device of FIG. 12 .
[0031] FIG. 14 is a sectional view of the airflow treatment container of FIG. 8 .
DESCRIPTION OF THE INVENTION
[0032] FIGS. 1-7 present various views of an airflow treatment device 100 that is configured to treat air in an air handling system. As will be discussed in more detail herein, the airflow treatment apparatus or device 100 is configured to be installed inline in the ductwork of an air handling system (e.g., HVAC system) in a manner that is substantially free of obstructing the airflow through the ductwork or requiring any supplemental power to treat the airflow passing by the treatment device. The disclosed airflow treatment device can also be maintained substantially free of any interruptions, disassembly or downtime to the air handling system after initial inline installation of the disclosed airflow treatment device 100 .
[0033] Broadly, the device 100 includes a first body 102 having a first wall 104 with opposite inner and outer surfaces 106 , 108 and opposite first and second open free ends 110 , 112 . The first wall 104 defines an airflow passageway 114 through the device 100 that extends between the first and second opposite open ends 110 , 112 of the first wall 104 along an airflow passageway (e.g., central) axis 116 (e.g., where the inner surface 106 of the first wall 104 generally defines and surrounds the airflow passageway 114 ). In this regard, the first and second opposite open ends 110 , 112 may refer to both the first and second opposite open ends of the first wall 104 and first and second opposite open ends of the airflow passageway 114 . The first and second open ends 110 , 112 are configured to connect with (e.g., receive, be received by) respective open ends of first and second ducts or duct members (e.g., see FIGS. 8-9 , discussed in more detail below) so that the airflow passageway 114 substantially seamlessly blends into the airflow passageways of the first and second ducts or duct members. While the first wall 104 is illustrated in the form of a generally tubular member having a circular cross section (e.g., a cylinder), the first wall 104 may have other cross-sectional shapes such as square, ovular, etc. (e.g., so as to generally match the cross-sectional shapes of the first and second ducts or duct members).
[0034] The device 100 also includes an arrangement for providing access to the airflow passageway 114 when the first and second open ends 110 , 112 are respectively interconnected to first and second ducts or duct members in a manner that is substantially free of interrupting or blocking the airflow passageway 114 and/or requiring disconnection of the first and second ducts or duct members from the first and second open ends 110 , 112 of the first body 102 . For instance, the device 100 may include a second body 118 having a second wall 120 with opposite inner and outer surfaces 122 , 124 and opposite first and second opposite open free ends 126 , 128 . The second wall 120 defines at least a first portion 130 a of an air treatment passageway 130 through the first wall 104 of the device 100 that extends between the first and second open ends 126 , 128 of the second wall 120 along an air treatment passageway axis 132 and that intersects the airflow passageway 114 at a position between the first and second open ends 110 , 112 of the first wall 104 . In this regard, the first and second opposite open ends 126 , 128 may refer to both the first and second opposite open ends of the second wall 120 and first and second opposite open ends of the air treatment passageway 130 .
[0035] As shown, the air treatment passageway 130 feeds substantially directly into the airflow passageway 114 to expose airflow passing through the airflow passageway 114 to one or more air treatment (e.g., odor neutralizing) substances or the like disposed within the air treatment passageway 130 . To limit or reduce airflow obstruction through the airflow passageway 114 , the second open end 128 of the second body 102 may extend into the airflow passageway 114 no more than about 50% of the inner diameter (or other inner maximum cross-dimension), such as no more than about 25% of the inner diameter (or other inner maximum cross-dimension). To facilitate appropriate interaction between the airflow and the air treatment substances, the second open end 128 of the second body 102 may extend into the airflow passageway 114 at least about 5% of the inner diameter, such as at least about 15%. In one arrangement, the second body 118 may be inserted partially through an aperture (not labeled) through the first wall 104 of the first body 102 and rigidly secured thereto in any appropriate manner. For instance, after insertion of the second body 118 through the first wall 104 , one or more connection members 134 (e.g., welds, etc.) may be used to rigidly and non-movably secure the second body 118 to the first body 102 (e.g., such as between the outer surface 124 of the second wall 120 and the inner surface 106 of the first wall 104 ).
[0036] In another arrangement, the second body 118 may be in the form of a pair of opposing second body members (e.g., where the first opposing body member includes the first open end 126 and the second opposing body member includes the second open end 128 ) that are respectively configured to attach to each other on opposite sides of the first wall 104 . As just one example, the first and second opposing body members may have respective corresponding threaded surfaces (or other respective corresponding connection members such as spring-loaded members and correspondingly shaped holes) that are configured to appropriately engage with each other. In this regard, the first and second opposing body members may be placed over the aperture through the first wall 104 adjacent the outer and inner surfaces 108 , 106 , respectively, and threadably secured to each other. In a further arrangement, the first and second bodies 102 , 118 be part of a one-piece body that defines the airflow passageway 114 and the air treatment passageway 130 . That is, the device 100 may be in the form of an integral, one-piece member that may be fabricated in any appropriate manner (e.g., blow molding, injection molding, etc.).
[0037] In any case, the first open end 126 of the second wall 120 may be disposed outside of the airflow passageway 114 to facilitate interconnection with an air treatment container 200 (e.g., jar, bottle, glass, vial, jug, etc., see FIGS. 8 , 9 and 14 ) having an air treatment substance therein. Stated differently, the first open end 126 may provide an opening into the air treatment passageway 130 and thus access to the airflow passageway 114 for the air treatment substance disposed in the air treatment container 200 . With reference to FIGS. 8 and 14 , the air treatment container 200 may include a body 202 (e.g., a “third” body) having a wall 204 (e.g., a “third” wall) with opposite inner and outer surfaces 206 , 207 , a closed first free end 208 , and an opposite open second free end 210 . The third wall 204 defines at least a second portion 130 b of the air treatment passageway 130 that extends between the first and second ends 208 , 210 of the third wall 204 along the air treatment axis 132 and that is configured to feed into the first portion 130 a of the air treatment passageway 130 (e.g., when the second open end 210 of the air treatment container 200 is releasably secured to the first open end 126 of the second body 118 ).
[0038] The device 100 and the air treatment container 200 include respective first and second releasable interconnection apparatuses 136 , 212 that engage to releasably secure the air treatment container 200 to the device 100 so that the second portion of the air treatment passageway 130 within the air treatment container 200 aligns with and feeds into the first portion of the air treatment passageway 130 within the second body 118 of the device 100 . For instance, the first releasable interconnection apparatus 136 may be in the form of a first set of threads disposed on the inner surface 122 of the second body 118 adjacent the first open end 126 while the second releasable interconnection apparatus 212 may be in the form of a second set of threads (complimentary to the first set of threads) disposed on the outer surface 207 of the third body 202 adjacent the second open end 210 . Furthermore, the second open end 210 of the third body 202 may be sized and shaped to be received through the first open end 126 and into the second body 118 .
[0039] In this regard, a user may align the second open end 210 of the third body 202 with the first open end 126 of the second body 118 and then rotate the third body 202 about the air treatment axis 132 to threadingly engage the first and second sets of threads and releasably secure the air treatment container 200 to the device 100 . In one arrangement, the first set of threads may be disposed on the outer surface 124 of the second body 118 while the second set of threads may be disposed on the inner surface 206 of the third body 202 adjacent the second open end 210 . In this regard, the first open end 126 of the second body 118 would be received inside the second open end 210 of the third body 202 . The first and second releasable interconnection apparatuses 136 , 212 may also take other forms such as complimentary magnetic mechanisms, “twist and click” type mechanisms, and/or the like.
[0040] In some situations, the second open end 210 of the third body 202 may not be sized and shaped to be received through the first open end 126 and into the second body 118 . In this regard, a coupler or adapter 300 may be provided (see FIGS. 10-11 ) that is broadly configured to releasbly interconnect the air treatment container 200 to the device 100 . As shown, the adapter 300 may include a body 302 (e.g., a “fourth” body) having a wall 304 (e.g., a “fourth” wall) with opposite inner and outer surfaces 306 , 307 and first and second opposite open free ends 308 , 310 . The fourth wall 304 defines at least a third portion 130 c of the air treatment passageway 130 that extends between the first and second ends 308 , 310 of the third wall 304 along the air treatment axis 132 and that feeds into the first and second portions 130 a, 130 b of the air treatment passageway 130 (e.g., when the first and second open ends 308 , 310 are respectively releasably secured to the second open end 212 of the third body 202 and the first open end 126 of the second body 118 ). The first open end 308 of the fourth body 302 may be sized and shaped to receive the second open end 210 of the third body 202 while the second open end 310 of the fourth body 302 may be sized to be received in the first open end 126 of the second body 118 (or vice versa).
[0041] The adapter 300 may include first and second releasable interconnection apparatuses 312 , 314 that are respectively releasably interconnectable with the second releasable interconnection apparatus 212 of the third body 212 and the first releasable interconnection apparatus 136 of the second body 118 . In one arrangement, the first releasable interconnection apparatus 312 may be in the form of a first set of threads that are configured to threadingly engage with the set of threads disposed adjacent the second open end 210 of the third body 302 while the second releasable interconnection apparatus 314 may be in the form of a second set of threads that are configured to threadingly engage with the set of threads disposed adjacent the first open end 126 of the second body 118 . For instance, the first set of threads may be disposed on the inner surface 306 adjacent the first open end 308 of the fourth body 302 while the second set of threads may be disposed on the outer surface 307 adjacent the second open end 310 of the fourth body 302 (or vice versa). The first and second releasable interconnection apparatuses 312 , 314 may also take other forms such as complimentary magnetic mechanisms, “twist and click” type mechanisms, and/or the like. The adapter 300 may take various forms, shapes and sizes to interconnect air treatment containers 200 of various forms, shapes and sizes with the device 100 .
[0042] One method of installing and using the device 100 will now be described to facilitate the reader's understanding of the device 100 . With initial reference to FIG. 8 , a user may identify a location along the ductwork of an air handling system in which to install the device 100 . For instance, the device 100 may be installed in a portion of the ductwork leading into the blower fan (e.g., on the draw or intake side). Once a location has been identified, the user may appropriately sever or cut the ductwork to obtain first and second ductwork members 400 1 , 400 2 . Depending upon the particular circumstances, the severing may include severing the ductwork at first and second locations to remove a section of the ductwork.
[0043] In any case, the first and second ductwork members 400 1 , 400 2 may generally be in the form of hollow tubular member having respective open ends 402 1 , 402 2 . The open end 402 1 of the first ductwork member 400 1 may then be appropriately secured over the first open end 110 of the first body 102 and the open end 402 2 of the second ductwork member 400 2 may then be appropriately secured over the second open end 112 of the first body 102 in any appropriate manner. As just one example, first and second hose clamps 404 1 , 404 2 may be initially disposed over the respective open ends 402 1 , 402 2 of the first and second ductwork members 400 1 , 400 2 or the first and second open ends 110 , 112 of the first body 102 . After the respective open ends 402 1 , 402 2 of the first and second ductwork members 400 1 , 400 2 have been placed over the first and second open ends 110 , 112 of the first body 102 , the first and second hose clamps 404 1 , 404 2 may be respectively slid over the overlapping portions of the open ends 402 1 , 402 2 and the first and second open ends 110 , 112 and then tightened to secure the open ends 402 1 , 402 2 to the body 102 . See FIG. 9 .
[0044] In one arrangement, the outer surface 108 of the first body 102 may include one or more retention features such as first and second retention protrusions 111 , 113 (e.g., bumps, etc.) adjacent the first and second open ends 110 , 112 that are configured to respectively resist removal of the first and second ductwork members 400 1 , 400 2 from the first and second open ends 110 , 112 of the first body 102 . For instance, the open ends 402 1 , 402 2 of the first and second ductwork members 400 1 , 400 2 may be pulled or pushed over the first and second open ends 110 , 112 of the first body 102 so as to extend at least partially past the respective first and second retention protrusions 111 , 113 . In one arrangement, a respective plurality of each of the first and second retention protrusions 111 , 113 may be respectively disposed adjacent the first and second open ends 110 , 112 of the first body 102 .
[0045] In the case where the open ends 402 1 , 402 2 of the first and second ductwork members 400 1 , 400 2 have respective inner diameters less than outer diameters of the first and second open ends 110 , 112 of the first body 102 and have sufficient levels of elasticity, the first and second ductwork members 400 1 , 400 2 may be sufficiently secured to the first body 102 at this point. Additionally or alternatively, the first and second hose clamps 404 1 , 404 2 may be used as discussed above. While the first and second hose clamps 404 1 , 404 2 and/or first and second retention protrusions 111 , 113 have been disclosed to secure the first and second ductwork members 400 1 , 400 2 to the first and second open ends 110 , 112 of the first body 102 , other manners of securing the same are envisioned and encompassed herein.
[0046] In one arrangement, the device 100 may be appropriately hung from or otherwise secured to a fixed member (e.g., structural member of the house or building, such as a joist, etc.) at a point above the first and second ductwork members 400 1 , 400 2 to limit or otherwise reduce the load placed on the first and second ductwork members 400 1 , 400 2 by the device 100 (as well as by the air treatment container 200 and/or adapter 300 ). As just one example, the device 100 may have a first connector member 138 (e.g., hole, hook, opening, etc.) disposed on the outer surface 108 of the first body 102 that is configured to connect with or attach to a corresponding second connector member (e.g., hook, hole, etc., not shown) on a joist or other fixed member of the house or building (not shown).
[0047] In any case, the airflow passage 114 of the first body 102 substantially seamlessly feeds or blends into those of the first and second ductwork members 400 1 , 400 2 (and thus the rest of the air handling system) once the open ends 402 1 , 402 2 are secured over the first and second open ends 110 , 112 of the first body 102 . Either before or after the device 100 is secured to the first and second ductwork members (or vice versa), the air treatment container 200 including an air treatment (e.g., odor treatment or elimination) substance (e.g., liquid, solid, etc.) may be releasably secured to the second body 118 of the device 100 (as discussed previously) so that the second portion 130 b of the air treatment passageway 130 (inside the air treatment container 200 ) aligns with and feeds into the first portion 130 a of the air treatment passageway 130 (inside the second body 118 ), the latter of which feeds directly into the airflow passageway 114 . If necessary, the adapter 300 may be used as previously discussed to interconnect the air treatment container 200 to the device 100 .
[0048] Upon operation of the air handling system so that the blower fan or other device moves air through the first ductwork member 400 1 , the airflow passageway 114 of the device 100 , and then the second ductwork member 400 2 (or vice versa), the air interacts with the air treatment substance in the air treatment container 200 via the air treatment passageway 130 to neutralize or otherwise treat the air traveling through the air handling system and/or through one or more registers into one or more rooms of the home or building. In one arrangement, the second body 118 may include a screening element 140 (e.g., filter, etc.) disposed across the first portion 130 a of the air treatment passageway 130 to limit particulates and/or the like in the air treatment substance from being sucked into the airflow passing through the airflow passageway 114 and into the ductwork of the air handling system. For instance, the screening element 140 may be disposed adjacent the second open end 128 of the second body 118 . In one arrangement, at least a portion of the screening element 140 may extend at least a portion past the second free end 128 . In other arrangements, the screening element 140 may additionally or alternatively be disposed in other locations such as across the second portion 130 b of the air treatment passageway 130 adjacent the open second end 210 of the air treatment container 200 , across the third portion 130 c of the air treatment passageway 130 in the adapter 300 , and/or the like.
[0049] Continued cycling of the air through the air handling system and the device 100 results in increased degrees of neutralizing and/or treatment of the air. The air treatment container 200 may be removed (e.g., unscrewed, unclipped, etc.) from the device 100 to recharge, replenish, etc. the air treatment substance in the air treatment container according to any appropriate schedule (e.g., every month, every six months, etc.), upon the substance dropping below a certain level, upon the substance changing colors indicating that new and/or additional substance is needed, etc. Alternatively, the air treatment container 200 may be removed from the device 100 and a new air treatment container 100 (e.g., with new air treatment substances therein) may be installed into the device 100 as discussed above. More than one device 100 and corresponding container 200 may be installed inline in a single air handling system (e.g., in each of one or more ducts of the system). In one arrangement, the device 100 and air treatment container 100 (e.g., with or without air treatment substances therein) may be supplied as or otherwise form a kit. For instance, the device 100 and air treatment container 200 may be disposed in a common packaging and supplied to retailers, sold to customers, etc. In this arrangement, the air treatment container may be releasably secured to the device 100 or not secured to the device 100 but releasably securable to the device (i.e., capable of being releasably secured to the device 100 as disclosed herein).
[0050] As shown in the figures, the air treatment passageway axis 132 may in some embodiments be substantially perpendicular to the airflow passageway axis 116 . In other arrangements, however, the air treatment passageway axis 132 may be other than substantially perpendicular to the airflow passageway axis 116 . For instance, the air treatment passageway axis 132 may be disposed at angles greater than or less than 90° relative to the airflow passageway axis 116 (e.g., 30°, 45°, 120°, etc.). In one embodiment, a device 100 may include more than a single air treatment passageway 130 for respective interconnection to more than a single air treatment container 200 . As an example, FIG. 12-13 illustrate another embodiment of the device 100 ′ that includes a plurality of (e.g., such as first and second) second bodies 118 1 , 118 2 that define a respective plurality of (e.g., such as first and second) air treatment passageway first portions 130 a 1 , 130 a 2 along a respective plurality of (e.g., such as first and second) air treatment passageway axes 132 1 , 132 2 . For instance, each of the air treatment passageway axes 132 1 , 132 2 may be substantially perpendicular to each other as well as to the airflow passageway axis 116 as shown in FIGS. 12-13 . In one arrangement, one or both of the air treatment passageway axes 132 1 , 132 2 may be other than perpendicular to the airflow passageway axis 116 and/or than that perpendicular to each other.
[0051] The device 100 , container 200 , adapter 300 , ductwork members 400 , etc. may be constructed of any appropriate materials (e.g. plastics, metals, composites, and/or the like) and in any appropriate manner. In one arrangement, the device 100 may be constructed out of plastic using any appropriate manufacturing process. For instance, a polyurethane mix may be procured and added to a tooling mold in the shape of the device 100 (e.g., the first and/or second bodies 102 , 118 ) and allowed to catalyze until hardened. A similar process may be used to fabricate the adapter 300 . Alternatively, metered injection molding systems and/or 3D printing technologies may be used. Still further, various metallic manufacturing processes may be used to fabricate one or more of the components. In one arrangement, the air treatment container 200 may be in the form of a glass jar (e.g., a Mason jar) or the like.
[0052] The foregoing description has been presented for purposes of illustration and description. Furthermore, the description is not intended to limit the invention to the form disclosed herein. Consequently, variations and modifications commensurate with the above teachings, and skill and knowledge of the relevant art, are within the scope of the present invention. In one arrangement, the device 100 may only include the first body 102 , where the first body 102 includes a threaded aperture through the first wall 104 (e.g., at location where second body 118 is disposed in the figures) that is sized and shaped to receive the second open end 210 of the air treatment container or the second open end 310 of the adapter and that leads into the airflow passageway 114 . For instance, the first and second open ends 110 , 112 may include first and second openings while the threaded opening through the first wall 104 may be a third opening. In this regard, the air treatment container 200 or adapter 300 may be threaded directly into the third aperture so that the second portion 130 b of the air treatment passageway becomes the first portion and thus feeds directly into the airflow passageway 114 of the first body 102 .
[0053] In some arrangements, the entirety of the airflow passageway 114 and/or the air treatment passageway 130 need not necessarily respectively extend along the same straight airflow passageway axis 116 and/or air treatment passageway axis 132 . Stated differently, the airflow passageway 114 and/or the air treatment passageway 130 may each follow non-straight paths between the first and second opposite open ends. For instance, in the event the device 100 was to be used in a situation where the respective open ends 402 1 , 402 2 of the first and second ductwork members 400 1 , 400 2 came together other than substantially collinearly as shown in FIG. 8 , the first body 102 may be appropriately fabricated so that the airflow passageway 114 through the first body 102 follows a curvilinear path (e.g., a substantial U-shape), follows first and second perpendicular axes (e.g., a substantial V-shape, such as where the first axis passes through the first open end 110 and the second axis passes through the second open end 112 , and where the first and second perpendicular axes intersect at a mid-point of the first body 102 ), etc. As another example, it is not necessary that the air treatment passageway 130 follows a completely straight path from the first closed end 208 of the air treatment container 200 and the second open end of the second body 118 .
[0054] In one embodiment, a cap may be provided with the device (e.g., in a kit) for use in closing or otherwise sealing off access to the airflow passageway 114 via the second body 118 or otherwise through the first wall 104 of the first body 102 . For instance, the cap may have a closed head portion and a threaded portion protruding from the head portion that is configured to be inserted into the second body 102 and threadingly engage with the set of threads of the second body 102 ; this may be advantageous to use when the air treatment container 200 has been removed from the device 100 for any appropriate reason to limit airflow leakage from the device 100 .
[0055] It is also to be understood that the various components disclosed herein have not necessarily been drawn to scale. Also, many components have been labeled herein as “first,” “second,” “third,” etc. merely to assist the reader in understanding the relationships between the various components. One or more various combinations of the above discussed arrangements and embodiments are also envisioned. While this disclosure contains many specifics, these should not be construed as limitations on the scope of the disclosure or of what may be claimed, but rather as descriptions of features specific to particular embodiments of the disclosure. Furthermore, certain features that are described in this specification in the context of separate embodiments can also be implemented in combination in a single embodiment. Conversely, various features that are described in the context of a single embodiment can also be implemented in multiple embodiments separately or in any suitable subcombination. Moreover, although features may be described above as acting in certain combinations and even initially claimed as such, one or more features from a claimed combination can in some cases be excised from the combination, and the claimed combination may be directed to a subcombination or variation of a subcombination. | An airflow treatment device configured to be installed inline in the ductwork of an air handling system (e.g., HVAC system) in a manner that is substantially free of obstructing the airflow through the ductwork or requiring any supplemental power to treat the airflow passing by the treatment device. The disclosed airflow treatment device can also be maintained substantially free of any interruptions, disassembly or downtime to the air handling system after initial inline installation of the disclosed device. In one arrangement, the airflow treatment device is capable of accepting a threaded odor neutralizer container at its base. Ductwork need only be disassembled once to attach the disclosed device inline in the airflow path of the ductwork. When the odor neutralizing agent needs replenished, the container can be detached from the device, replenished, and reattached to the device free of disruption to the air flow of the air handling system. | 0 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a continuation of U.S. patent application Ser. No. 10/362,848, filed Oct. 14, 2003 now U.S. Pat. No. 7,304,122, which is a continuation under 35 U.S.C. §371 of PCT/US01/27288, filed Aug. 30, 2001 and published as WO 02/18477 on Mar. 7, 2002, which claims priority from U.S. patent application Ser. No. 09/651,338, filed Aug. 30, 2000, now U.S. Pat. No. 6,503,538, which applications and publications are incorporated herein by reference.
BACKGROUND OF THE INVENTION
While they potentially offer many advantages due to their “organic nature,” conventional poly(α-amino acids) possess many undesirable physical, chemical and biodegradation properties. For example, the biological and material properties of conventional poly(α-amino acids) cannot be varied over a wide range. In addition, the synthesis of many conventional poly(α-amino acids) is difficult and expensive.
A considerable amount of attention has therefore been focused on replacing the amide (peptide) linkage in the conventional poly(α-amino acids) with a variety of non-amide bonds to provide novel polymeric systems that are based on α-amino acids. One class of α-amino acid derived polymers are polyisopeptides (alternatively known as pseudo-poly(amino acids)), which belong to the XY-type heterochain polymers. Polyisopeptides are usually formed by linking trifunctional α-amino acids in the backbone chains. However, relatively few attempts have been made to synthesize polyisopeptides. For example, Sekiguchi et al. obtained poly-β-(α-allyl-L-aspartate) by the ring-opening polymerization of β-lactams. See, Rodriguez-Galan, A. et al., Makromol. Chem., Macromol. Symp., 6, 277 (1986) and Vives, J. et al., Makromol. Chem., Rapid Commun., 10(1):13 (1989). One major limiting feature of polyisopeptides is that structural modifications are limited solely to chemical variations at the N-acyl residue of the polyisopeptide. This narrow range of chemical modification has resulted in an undesirably narrow range of material properties of these polymers.
Another class of α-amino acid derived polymers are amino acid based bioanalagous polymers (AABBPs), which belong to the XX-YY heterochain polymers. AABBPs are mainly obtained by the polycondensation of XX (one type of monomer having two X functional groups) and YY (another type of monomer having two Y functional groups). AABBPs are not pure polyamino acids or pseudo-polyamino acids because they include residues of other types of monomers (e.g., dicarboxylic acids and diols).
One class of AABBPs are poly(ester ureas) (PEUs), which are prepared from bis-α-aminoacyl diol monomers. The first attempt to use bis-α-aminoacyl(phenylalanyl) diol for preparing bioabsorbable, semi-physiological polymers similar to poly(ester urea) was by Huang et al. Huang S. J., et al., J. Appl. Polym. Sci., 23(2): 429 (1979). Only low-molecular-weight PEUs, having limited material properties, could be prepared by this route.
Lipatova et al. have also synthesized semi-physiological poly(ester urethane ureas) from bis-L-phenylalanyl diols, diols, and diisocyanates. Lipatova T. E., et al., Dokl. Akad. Nauk SSSR, 251(2): 368 (1980) and Gladyr I. I., et al. Vysokomol. Soed., 31B(3): 196 (1989). However, no information on the synthesis of the starting material (e.g., α-diamino diesters) was given.
Yoneyama et al. reported on the synthesis of high-molecular-weight semi-physiological PEUs by the interaction of free α-diamino-diesters with non-physiological diisocyanates. Yoneyama M., et al., Polym. Prepr. Jpn., 43(1): 177 (1994). Contrary to Huang et al. (Huang S. J., et al., J. Appl. Polym. Sci., 23(2): 429(1979)), high-molecular-weight PEUs were obtained in some cases. In view of this preliminary data, there remains an ongoing need for novel polymers based on α-amino acids that possess a wide range of physical, chemical and biodegradation properties.
SUMMARY OF THE INVENTION
The present invention provides polymers that are based on α-amino acids. In contrast to conventional poly(α-amino acids), the polymers of the present invention (e.g., elastomeric functional copolyester amides and copolyester urethanes) possess advantageous physical, chemical and biodegradation properties. For example, the polymers of the present invention possess suitable biodegradation (weight loss percent) properties under varying conditions, (see, Table III). The hydrolysis of the polymers can be catalyzed by hydrolases (e.g., trypsin, α-chymotrypsin, lipase, etc.). As such, the polymers can be used as carriers for covalent immobilization (attachment) of various drugs and other bioactive substances. In addition, the enzyme catalyzed biodegradation rates of the polymer of the present invention can be changed by varying the polymer composition (e.g., l/p ratio) and/or the nature of the functional groups (e.g., dicarboxylic acids, diols, or α-amino acids).
The present invention provides a polymer of formula (VII):
wherein
m is about 0.1 to about 0.9;
p is about 0.9 to about 0.1;
n is about 50 to about 150;
each R 1 is independently (C 2 -C 20 )alkylene;
each R 2 is independently hydrogen, or (C 6 -C 10 )aryl(C 1 -C 6 )alkyl;
each R 3 is independently hydrogen, (C 1 -C 6 )alkyl, (C 2 -C 6 )alkenyl, (C 2 -C 6 )alkynyl, or (C 6 -C 10 )aryl(C 1 -C 6 )alkyl; and
each R 4 is independently (C 2 -C 20 )alkylene;
comprising one or more subunits of the formula (I):
and one or more subunits of the formula (II):
wherein
the combined number of subunits (I) and (II) is about 50 to about 150.
Specifically, each R 1 can independently be (CH 2 ) 4 , (CH 2 ) 8 , or (CH 2 ) 12 ; R 2 can independently be hydrogen or benzyl; each R 3 can independently be iso-butyl or benzyl; and R 4 can independently be (CH 2 ) 4 , (CH 2 ) 6 , (CH 2 ) 8 , or (CH 2 ) 12 .
The present invention also provides a polymer of formula (VII):
wherein
m is about 0.1 to about 0.9;
p is about 0.9 to about 0.1;
n is about 50 to about 150;
each R 1 is independently (C 2 -C 20 )alkylene;
each R 2 is independently hydrogen, or (C 6 -C 10 )aryl(C 1 -C 6 )alkyl;
each R 3 is independently hydrogen, (C 1 -C 6 )alkyl, (C 2 -C 6 )alkenyl, (C 2 -C 6 )alkynyl, or (C 6 -C 10 )aryl(C 1 -C 6 alkyl; and
each R 4 is independently (C 2 -C 20 )alkylene.
Specifically, each R 1 can independently be (CH 2 ) 4 , (CH 2 ) 8 , or (CH 2 ) 12 ; each R 2 can independently be hydrogen or benzyl; each R 3 can independently be iso-butyl or benzyl; each R 4 can independently be (CH 2 ) 4 , (CH 2 ) 6 , (CH 2 ) 8 , or (CH 2 ) 12 ; p/(p+m) can be about 0.9 to about 0.1; and m/(p+m) can be about 0.1 to about 0.9.
The present invention also provides a polymer of formula (VII) formed from an amount of one or more compounds of formula (III):
wherein
each R 3 is independently hydrogen, (C 1 -C 6 )alkyl, (C 2 -C 6 )alkenyl, (C 2 -C 6 )alkynyl, or (C 6 -C 10 )aryl(C 1 -C 6 )alkyl; and
R 4 is independently (C 2 -C 20 )alkylene; or a suitable salt thereof; and
an amount of one or more compounds of formula (IV):
wherein
R 2 is independently hydrogen, or (C 6 -C 10 )aryl(C 1 -C 6 )alkyl; or a suitable salt thereof; and
an amount of one or more compounds of formula (V):
wherein
R 1 is independently (C 2 -C 20 )alkylene; and
each R 5 is independently (C 6 -C 10 )aryl, optionally substituted with one or more nitro, cyano, halo, trifluoromethyl, or trifluoromethoxy.
Specifically, R 1 can independently be (CH 2 ) 4 , (CH 2 ) 8 , or (CH 2 ) 12 ; R 2 can independently be hydrogen or benzyl; each R 3 can independently be isobutyl or benzyl; R 4 can independently be (CH 2 ) 4 , (CH 2 ) 6 , (CH 2 ) 8 , or (CH 2 ) 12 ; each R 5 can independently be p-nitrophenyl; the compound of formula (III) can be the di-p-tolunesulfonic acid salt of a bis-(L-α-amino acid)-α,ω-alkylene diester; the compound of formula (IV) can be the di-p-tolunesulfonic acid salt of L-lysine benzyl ester; and the compound of formula (V) can be di-p-nitrophenyl adipate, di-p-nitrophenyl sebacinate, or di-p-nitrophenyl dodecyldicarboxylate.
The present invention also provides a method for preparing a polymer of formula (VII):
wherein
m is about 0.1 to about 0.9;
p is about 0.9 to about 0.1;
n is about 50 to about 150;
each R 1 is independently (C 2 -C 20 )alkylene;
each R 2 is independently hydrogen, or (C 6 -C 10 )aryl(C 1 -C 6 )alkyl;
each R 3 is independently hydrogen (C 1 -C 6 )alkyl, (C 2 -C 6 )alkenyl, (C 2 -C 6 )alkynyl, or (C 6 -C 10 )aryl(C 1 -C 6 )alkyl; and
each R 4 is independently (C 2 -C 20 )alkylene;
comprising contacting an amount of one or more compounds of formula (III):
or a suitable salt thereof; and
an amount of one or more compounds of formula (IV):
or a suitable salt thereof; and
an amount of one or more compounds of formula (V):
wherein
each R 5 is independently (C 6 -C 10 )aryl optionally substituted with one or more nitro, cyano, halo, trifluoromethyl, or trifluoromethoxy;
under suitable conditions to provide the polymer of formula (VII).
Specifically, each R 1 can independently be (CH 2 ) 4 , (CH 2 ) 8 , or (CH 2 ) 12 ; each R 2 can independently be hydrogen or benzyl; each R 3 can independently be isobutyl or benzyl; each R 4 can independently be (CH 2 ) 4 , (CH 2 ) 6 , (CH 2 ) 8 , or (CH 2 ) 12 ; each R 5 can be p-nitrophenyl; the compound of formula (III) can be the di-p-tolunesulfonic acid salt of a bis-(L-α-amino acid)-α,ω-alkylene diester, the compound of formula (IV) can be the di-p-tolunesulfonic acid salt of L-lysine benzyl ester; the compound of formula (V) can be di-p-nitrophenyl adipate, di-p-nitrophenyl sebacinate, or di-p-nitrophenyl dodecyldicarboxylate; p/(p+m) can be about 0.9 to about 0.1; and m/(p+m) can be about 0.1 to about 0.9. The contacting can be carried out in the presence of a base, wherein the base can be triethylamine. The contacting can also be carried out in the presence of a solvent, wherein the solvent can be N,N-dimethylacetamide. The contacting can also be carried out at a temperature of about 50° C. to about 100° C. The contacting can preferably occur for about 10 hours to about 24 hours. The polymer of formula (VII) can also optionally be purified.
The present invention also provides a polymer of formula (XI):
wherein
m is about 0.1 to about 0.9;
p is about 0.9 to about 0.1;
n is about 50 to about 150;
each R 2 is independently hydrogen, or (C 6 -C 10 )aryl(C 1 -C 6 )alkyl;
each R 3 is independently hydrogen, (C 1 -C 6 )alkyl, (C 2 -C 6 )alkenyl, (C 2 -C 6 )alkynyl, or (C 6 -C 10 )aryl(C 1 -C 6 )alkyl;
each R 4 is independently (C 2 -C 20 )alkylene; and
each R 6 is independently (C 2 -C 20 )alkylene or (C 2 -C 8 )alkyloxy(C 2 -C 20 )alkylene;
comprising one or more subunits of the formula (VIII):
wherein
each R 3 is independently hydrogen, (C 1 -C 6 )alkyl, (C 2 -C 6 )alkenyl, (C 2 -C 6 )alkynyl, or (C 6 -C 10 )aryl(C 1 -C 6 )alkyl; and
R 4 is independently (C 2 -C 20 )alkylene;
R 6 is independently (C 2 -C 20 )alkylene or (C 2 -C 8 )alkyloxy(C 2 -C 20 )alkylene; and
one or more subunits of the formula (IX):
wherein
the total number of subunits (VIII) and (IV) is about 50 to about 150;
R 2 is independently hydrogen, (C 1 -C 6 )alkyl, or (C 6 -C 10 )aryl(C 1 -C 6 )alkyl.
Specifically, R 2 can independently be hydrogen or benzyl; each R 3 can independently be iso-butyl or benzyl; R 4 can independently be (CH 2 ) 4 , (CH 2 ) 6 , (CH 2 ) 8 , or (CH 2 ) 12 ; and R 6 can independently be (CH 2 ) 3 or (CH 2 )—O—(CH 2 ) 2 .
The present invention also provides a polymer of formula (XI):
wherein
m is about 0.1 to about 0.9;
p is about 0.9 to about 0.1;
n is about 50 to about 150;
each R 2 is independently hydrogen, or (C 6 -C 10 )aryl(C 1 -C 6 )alkyl;
each R 3 is independently hydrogen, (C 1 -C 6 )alkyl, (C 2 -C 6 )alkenyl, (C 2 -C 6 )alkynyl, or (C 6 -C 10 )aryl(C 1 -C 6 )alkyl;
each R 4 is independently (C 2 -C 20 )alkylene; and
each R 6 is independently (C 2 -C 20 )alkylene or (C 2 -C 8 )alkyloxy(C 2 -C 20 )alkylene.
Specifically, each R 2 can independently be hydrogen or benzyl; each R 3 can independently be iso-butyl or benzyl; each R 4 can independently be (CH 2 ) 4 , (CH 2 ) 6 , (CH 2 ) 8 , or (CH 2 ) 12 ; each R 6 can independently be (CH 2 ) 3 or (CH 2 ) 2 —O—(CH 2 ) 2 ; p/(p+m) can be about 0.9 to about 0.1; and m/(p+m) can be about 0.1 to about 0.9.
The present invention also provides a polymer of formula (XI) formed from an amount of one or more compounds of formula (III):
wherein
each R 3 is independently hydrogen, (C 1 -C 6 )alkyl, (C 2 -C 6 )alkenyl, (C 2 -C 6 )alkynyl, or (C 6 -C 10 )aryl(C 1 -C 6 )alkyl; and
R 4 is independently (C 2 -C 20 )alkylene; or a suitable salt thereof; and
an amount of one or more compounds of formula (IV):
wherein
R 2 is independently hydrogen, or (C 6 -C 10 )aryl(C 1 -C 6 )alkyl; or a suitable salt thereof; and
an amount of one or more compounds of formula (X):
wherein
each R 5 is independently (C 6 -C 10 )aryl optionally substituted with one or more nitro, cyano, halo, trifluoromethyl, or trifluoromethoxy; and
R 6 is independently (C 2 -C 20 )alkylene or (C 2 -C 8 )alkyloxy(C 2 -C 20 )alkylene.
Specifically, R 2 can independently be hydrogen or benzyl; each R 3 can independently be iso-butyl or benzyl; R 4 can independently be (CH 2 ) 4 , (CH 2 ) 6 , (CH 2 ) 8 , or (CH 2 ) 12 ; each R 5 can be p-nitrophenyl; R 6 can independently be (CH 2 ) 3 or (CH 2 ) 2 —O—(CH 2 ) 2 ; the compound of formula (III) can be the di-p-tolunesulfonic acid salt of a bis-(L-α-amino acid)-α,ω-alkylene diester; the compound of formula (IV) can be the di-p-tolunesulfonic acid salt of L-lysine benzyl ester, the compound of formula (X) can be 1,3-bis(4nitro-phenoxycarbonyloxy)propane; or 2,2′-bis-4-nitrophenoxycarbonyloxy ethylether; p/(p+m) can be about 0.9 to about 0.1; and m/(p+m) can be about 0.1 to about 0.9.
The present invention also provides a method for preparing a polymer of formula (XI):
wherein
m is about 0.1 to about 0.9;
p is about 0.9 to about 0.1;
n is about 50 to about 150;
each R 2 is independently hydrogen or (C 6 -C 10 )aryl(C 1 -C 6 )alkyl;
each R 3 is independently hydrogen, (C 1 -C 6 )alkyl, (C 2 -C 6 alkenyl, (C 2 -C 6 )alkynyl, or (C 6 -C 10 )aryl(C 1 -C 6 )alkyl;
each R 4 is independently (C 2 -C 20 )alkylene;
each R 5 is independently (C 6 -C 10 )aryl optionally substituted with one or more nitro, cyano, halo, trifluoromethyl or trifluoromethoxy; and
each R 6 is independently (C 2 -C 20 )alkylene or (C 2 -C 8 )alkyloxy(C 2 -C 20 )alkylene;
comprising contacting an amount-of one or more compounds of formula (III):
or a suitable salt thereof; and
an amount of one or more compounds of formula (IV):
or a suitable salt thereof; and
an amount of one or more compounds of formula (X):
under suitable conditions to provide the polymer of formula (XI).
Specifically, each R 2 can independently be hydrogen or benzyl; each R 3 can independently be iso-butyl or benzyl; each R 4 can independently be (CH 2 ) 4 , (CH 2 ) 6 , (CH 2 ) 8 , or (CH 2 ) 12 ; each R 5 can be p-nitrophenyl; each R 6 can independently be (CH 2 ) 3 or (CH 2 ) 2 —O—(CH 2 ) 12 ; the compound of formula (III) can be the di-p-tolunesulfonic acid salt of a bis-(L-α-amino acid)-α,ω-alkylene diester; the compound of formula (IV) can be the di-p-tolunesulfonic acid salt of L-lysine benzyl ester; the compound of formula (X) can be 1,3-bis (4-nitro-phenoxycarbonyloxy) propane, or 2,2′-bis-4-nitrophenoxycarbonyloxy ethylether; p/(p+m) can be about 0.9 to about 0.1; and m/(p+m) can be about 0.1 to about 0.9. The contacting can be carried out in the-presence of a base, wherein the base can be triethylamine. The contacting can be carried out in the presence of a solvent, wherein the solvent can be N,N-methylacetamide. The contacting can be carried out at a temperature of about 50° C. to about 100° C. The contacting can occur for about 10 hours to about 24 hours. In addition, the polymer of formula (XI) can optionally be purified.
The biodegradation of the copolyester amides and copolyester urethanes of the present invention allows the delivery of essential α-amino acids to targeted sites (e.g., to facilitate wound repair of injured tissues). In addition, the polymers of the present invention can be used for the attachment free iminoxyl radicals for suppressing inconsolable cell proliferation, and heparin or hirudin for increasing hemocompatibility. These modified polymers can be used to coat stents to suppress restenosis. In addition, the polymers of the present invention can be used as polyacids for the application in gynecology as impregnated contraceptive agents, e.g., for the controlled release of ferrous gluconate and the like. Furthermore, the polymers of the present invention can be used as polyacids for the attachment of unsaturated compounds, e.g., allyl amine or allyl alcohol, to obtain photo-curable and cross-linkable biodegradable polymers. The present polymers can be cross-linked with other polymers containing double bonds to create hybrid materials.
The biological and material properties of the polymers of the present invention can be varied over a wide range because the polymers can be formed from starting materials having varying functional groups (e.g., dicarboxylic acids, diols, and α-amino acids). See, e.g., Examples 1-22. In contrast to conventional poly(α-amino acids), the elastomeric functional copolyester amides and copolyester urethanes of the present invention can be obtained in high yields. See, Table III. For example, the compounds of the present invention can be prepared in yields up to about 97%. In addition, the reaction conditions employed to prepare the polymers of the present invention are relatively simple and the reagents are relatively inexpensive.
The present invention also provides a polymer of formula (VII) that is linked to one or more drugs. The present invention also provides a polymer of formula (XI) that is linked to one or more drugs. A residue of the polymer can be linked directly to a residue of the drug. The residue of the polymer can be linked directly to the residue of the drug through an amide, ester, ether, amino, ketone, thioether, sulfinyl, sulfonyl, disulfide, or a direct linkage. The residue of the polymer can be linked directly to the residue of the drug through one of the following linkages: —N(R)C(═O)—, —C(═O)N(R)—, —OC(═O)—, —C(═O)O—, —O—, —C(═O)—, —S—, —S(O)—, —S(O) 2 —, —S—S—, —N(R)—, or C—C; wherein each R is independently H or (C 1 -C 6 )alkyl.
A residue of the polymer can be linked to a residue of the drug, through a linker. The linker can separate the residue of the polymer and the residue of the drug by about 5 angstroms to about 200 angstroms, inclusive, in length. The residue of the polymer can be linked to the linker and the linker can be linked to the residue of the drug, independently, through an amide, ester, ether, amino, ketone, thioether, sulfinyl, sulfonyl, disulfide, or a direct linkage. The residue of the polymer can be linked to the linker and the linker can be linked to the residue of the drug, independently, through one of the following linkages: —N(R)C(═O)—, —C(═O)N(R)—, —OC(═O)—, —C(═O)O—, —O—, —C(═O)—, —S—, —S(O)—, —S(O) 2 —, —S—S—, —N(R)—, or C—C; wherein each R is independently H or (C 1 -C 24 )alkyl. The linker can be a divalent radical of the formula W-A-Q wherein A is (C 1 -C 24 )alkyl, (C 2 -C 24 )alkenyl, (C 2 -C 24 )alkynyl, (C 3 -C 8 )cycloalkyl, or (C 6 -C 10 )aryl, wherein W and Q are each independently —N(R)C(═O)—, —C(═O)N(R)—, —OC(═O), —C(═O)O—, —O—, —S—, —S(O)—, —S(O) 2 —, —S—S—, —N(R)—, —C(═O)—, or a direct bond; wherein each R is independently H or (C 1 -C 6 )alkyl. The linker can be a 1,ω-divalent radical formed from a peptide or an amino acid. The peptide can comprise 2 to about 25 amino acids. The peptide can be poly-L-lysine, poly-L-glutamic acid, poly-L-aspartic acid, poly-L-histidine, poly-L-ornithine, poly-L-serine, poly-L-threonine, poly-L-tyrosine, poly-L-leucine, poly-L-lysine-L-phenylalanine, poly-L-arginine, or poly-L-lysine-L-tyrosine.
The one or more drugs can each independently be: a polynucleotide, polypeptide, oligonucleotide, gene therapy agent, nucleotide analog, nucleoside analog, polynucleic acid decoy, therapeutic antibody, abciximab, anti-inflammatory agent, blood modifier, anti-platelet agent, anti-coagulation agent, immune suppressive agent, anti-neoplastic agent, anti-cancer agent, anti-cell proliferation agent, or nitric oxide releasing agent.
The present invention also provides a formulation comprising a polymer of formula (VII) and one or more drugs. The present invention also provides a formulation comprising a polymer of formula (XI) and one or more drugs. The one or more drugs can each independently be: a polynucleotide, polypeptide, oligonucleotide, gene therapy agent, nucleotide analog, nucleoside analog, polynucleic acid decoy, therapeutic antibody, abciximab, anti-inflammatory agent, blood modifier, anti-platelet agent, anti-coagulation agent, immune suppressive agent, anti-neoplastic agent, anti-cancer agent, anti-cell proliferation agent, or nitric oxide releasing agent.
The present invention also provides a method of using a polymer of the present invention for use as a medical device, a pharmaceutical, a carrier for covalent immobilization of a drug, or a bioactive substance.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 illustrates the biodegradation (weight loss in mg/cm 2 ) of 4-amino TEMPO (“TAM”) attached to a representative compound, co-PEA, according to one embodiment.
FIG. 2 illustrates the kinetics of nitroxyl radical release from TAM attached to a representative compound, co-PEA, according to an embodiment of the invention.
DETAILED DESCRIPTION OF THE INVENTION
The following definitions are used, unless otherwise described: halo can be chloro, fluoro, bromo, or iodo. Alkyl, alkenyl, alkynyl, etc. denote both straight and branched groups; but reference to an individual radical such as “propyl” embraces only the straight chain radical, a branched chain isomer such as “isopropyl” being specifically referred to.
It will be appreciated by those skilled in the art that compounds of the invention having a chiral center may exist in and be isolated in optically active and racemic forms. Some compounds may exhibit polymorphism. It is to be understood that the present invention encompasses any racemic, optically-active, polymorphic, or stereoisomeric form, or mixtures thereof of a compound of the invention, which possess the useful properties described herein, it being well known in the art how to prepare optically active forms (for example, by resolution of the racemic form by recrystallization techniques, by synthesis from optically-active starting materials, by chiral synthesis, or by chromatographic separation using a chiral stationary phase).
The term “alkyl” refers to a monoradical branched or unbranched saturated hydrocarbon chain preferably having from 1 to 40 carbon atoms, more preferably 1 to 10 carbon atoms, and even more preferably 1 to 6 carbon atoms. This term is exemplified by groups such as methyl, ethyl, n-propyl isopropyl, -butyl, iso-butyl, n-hexyl, n-decyl, tetradecyl, and the like. As used herein, “alkyl” includes “substituted alkyl,” which refers to an alkyl group as defined above, having from 1 to 8 substituents, preferably 1 to 5 substituents, and more preferably 1 to 3 substituents, selected from the group consisting of alkoxy, cycloalkyl, acyl, amino, azido, cyano, halogen, hydroxyl keto, thioketo, carboxy, thiol, aryl, heteroaryl, heterocyclic, and nitro.
The term “alkaryl” refers to the groups -alkylene-aryl and -substituted alkylene-aryl where alkylene, substituted alkylene and aryl are defined herein. Such alkaryl groups are exemplified by benzyl, phenethyl and the like.
The term “alkoxy” refers to the groups alkyl-O—, alkenyl-O—, cycloalkyl-O—, cycloalkenyl-O—, and alkynyl-O—, where alkyl, alkenyl, cycloalkyl, cycloalkenyl and alkynyl are as defined herein. Preferred alkoxy groups are alkyl-O— and include, by way of example, methoxy, ethoxy, n-propoxy, iso-propoxy, n-butoxy, tert-butoxy, sec-butoxy, n-pentoxy, n-hexoxy, 1,2-dimethylbutoxy, and the like. As used herein, “alkoxy” includes “substituted alkoxy,” which refers to the groups substituted alkyl-O—, substituted alkenyl-O—, substituted cycloalkyl-, substituted cycloalkenyl-O—, and substituted alkynyl-O— where substituted alkyl, substituted alkenyl, substituted cycloalkyl, substituted cycloalkenyl and substituted alkynyl are as defined herein.
The term “alkenyl” refers to a monoradical of a branched or unbranched unsaturated hydrocarbon group preferably having from 2 to 40 carbon atoms, more preferably 2 to 10 carbon atoms and even more preferably 2 to 6 carbon atoms and having at least 1 and preferably from 1-6 sites of vinyl unsaturation. Preferred alkenyl groups include ethenyl (—CH═CH 2 ), n-propenyl (—CH 2 CH═CH), iso-propenyl (—C(CH 3 )═CH 2 ) and the like. As used herein, “alkenyl” includes “substituted alkenyl,” which refers to an alkenyl group as defined above having from 1 to 5 substituents, and preferably 1 to 3 substituents, selected from the group consisting of alkoxy, substituted alkoxy, cycloalkyl, substituted cycloalkyl, cycloalkenyl, substituted cycloalkenyl, acyl, acylamino, acyloxy, amino, substituted amino, aminoacyl, aminoacyloxy, oxyaminoacyl azido, cyano, halogen, hydroxyl, keto, thioketo, carboxy, carboxyalkyl, thioaryloxy, thioheteroaryloxy, thioheterocyclooxy, thiol, thioalkoxy, substituted thioalkoxy, aryl, aryloxy, heteroaryl, heteroaryloxy, heterocyclic, heterocyclooxy, hydroxyamino, alkoxyamino, nitro, —SO-alkyl —SO-substituted alkyl, —SO-aryl, —SO-heteroaryl, —SO 2 -alkyl, —SO 2 -substituted alkyl, —SO 2 -aryl and —SO 2 -heteroaryl.
The term “alkynyl” refers to a monoradical of an unsaturated hydrocarbon preferably having from 2 to 40 carbon atoms, more preferably 2 to 20 carbon atoms and even more preferably 2 to 6 carbon atoms and having at least 1 and preferably from 1-6 sites of acetylene (triple bond) unsaturation. Preferred alkynyl groups include ethynyl (—C≡CH), propargyl (—CH 2 C≡CH) and the like. As used herein, “alkynyl” includes “substituted alkynyl” which refers to an alkynyl group as defined above having from 1 to 5 substituents, and preferably 1 to 3 substituents, selected from the group consisting of alkoxy, substituted alkoxy, cycloalkyl, substituted cycloalkyl cycloalkenyl, substituted cycloalkenyl acyl, acylamino, acyloxy, amino, substituted amino, aminoacyl, aminoacyloxy, oxyaminoacyl, azido, cyano, halogen, hydroxyl, carboxy, carboxyalkyl, thioaryloxy, thioheteroaryloxy, thioheterocyclooxy, thiol, thioalkoxy, substituted thioalkoxy, aryl, aryloxy, heteroaryl, heteroaryloxy, heterocyclic, heterocyclooxy, hydroxyamino, alkoxyamino, nitro, —SO-alkyl, —SO-substituted alkyl, —S-aryl, —SO-heteroaryl, —SO 2 -alkyl, —SO 2 -substituted alkyl, —SO 2 -aryl and —SO 2 -heteroaryl.
The term “acyl” refers to the groups HC(O)—, alkyl-C(O)—, substituted alkyl-C(O)—, cycloalkyl-C(O)—, substituted cycloalkyl-C(O)—, cycloalkenyl-C(O)—, substituted cycloalkenyl-C(O)—, aryl-C(O)—, heteroaryl-C(O)— and heterocyclic-C(O)— where alkyl, substituted alkyl, cycloalkyl, substituted cycloalkyl, cycloalkenyl, substituted cycloalkenyl, aryl, heteroaryl and heterocyclic are as defined herein.
The term “aryl” refers to an unsaturated aromatic carbocyclic group of from 6 to 20 carbon atoms having a single ring (e.g., phenyl) or multiple condensed (fused) rings, wherein at least one ring is aromatic (e.g., naphthyl, dihydrophenanthrenyl, fluorenyl, or anthryl). Preferred aryls include phenyl, naphthyl and the like.
Unless otherwise constrained by the definition for the aryl substituent, such aryl groups can optionally be substituted with from 1 to 5 substituents, preferably 1 to 3 substituents, selected from the group consisting of hydroxy, thiol, acyl, alkyl alkoxy, alkenyl, alkynyl, cycloalkyl, aryl azido, carboxy, cyano, halo, nitro, heteroaryl, heterocyclic, sulfonamide. Preferred aryl substituents include alkyl, alkoxy, halo, cyano, nitro, and trihalomethyl.
The term “amino” refers to the group —NH 2 .
The term “cycloalkyl” refers to cyclic alkyl groups of from 3 to 20 carbon atoms having a single cyclic ring or multiple condensed rings. Such cycloalkyl groups include, by way of example, single ring structures such as cyclopropyl, cyclobutyl, cyclopentyl, cyclooctyl, and the like, or multiple ring structures such as adamantanyl, and the like. As used herein, “cycloalkyl” includes “substituted cycloalkyl,” which refers to cycloalkyl groups having from 1 to 5 substituents, and preferably 1 to 3 substituents, selected from the group consisting of alkoxy, cycloalkyl, acyl, amino, azido, cyano, halogen, hydroxyl, keto, carboxy, thiol, aryl, heteroaryl, heterocyclic, and nitro.
The term “halo” or “halogen” refers to fluoro, chloro, bromo and iodo.
“Haloalkyl” refers to alkyl as defined herein substituted by 1-4 halo groups as defined herein, which may be the same or different. Representative haloalkyl groups include, byway of example, trifluoromethyl, 3-fluorododecyl, 12,12,12-trifluorododecyl, 2-bromooctyl, 3-bromo-6-chloroheptyl, and the like.
The term “heteroaryl” refers to an aromatic group of from 1 to 15 carbon atoms and 1 to 4 heteroatoms selected from oxygen, nitrogen and sulfur within at least one ring (if there is more than one ring).
Unless otherwise constrained by the definition for the heteroaryl substituent, such heteroaryl groups can be optionally substituted with 1 to 5 substituents, preferably 1 to 3 substituents, selected from the group consisting of hydroxy, thiol, acyl, alkyl, alkoxy, alkenyl, alkynyl, cycloalkyl, alkaryl aryl, azido, carboxy, cyano, halo, nitro, heteroaryl, and heterocyclic. Preferred aryl substituents include alkyl, alkoxy, halo, cyano, nitro, and trihalomethyl. Such heteroaryl groups can have a single ring (e.g., pyridyl or furyl) or multiple condensed rings (e.g., indolizinyl or benzothienyl). Preferred heteroaryls include pyridyl, pyrrolyl and furyl.
The term “heterocycle” or “heterocyclic” refers to a monoradical saturated or unsaturated group having a single ring or multiple condensed rings, from 1 to 40 carbon atoms and from 1 to 10 hetero atoms, preferably 1 to 4 heteroatoms, selected from nitrogen, sulfur, phosphorus, and/or oxygen within the ring.
Unless otherwise constrained by the definition for the heterocyclic substituent, such heterocyclic groups can be optionally substituted with 1 to 5, and preferably 1 to 3 substituents, selected from the group consisting of alkoxy, cycloalkyl, acyl, amino, azido, cyano, halogen, hydroxyl, keto, carboxy, thiol, aryl and heterocyclic. Such heterocyclic groups can have a single ring or multiple condensed rings. Preferred heterocyclics include morpholino, piperidinyl and the like.
Examples of nitrogen heterocycles and heteroaryls include, but are not limited to, pyrrole, imidazole, pyrazole, pyridine, pyrazine, pyrimidine, pyridazine, indolizine, isoindole, indole, indazole, purine, quinolizine, isoquinoline, quinoline, phthalazine, naphthylpyridine, quinoxaline, quinazoline, cinnoline, pteridine, carbazole, carboline, phenanthridine, acridine, phenanthroline, isothiazole, phenazine, isoxazole, phenoxazine, phenothiazine, inidazolidine, imidazoline, piperidine, piperazine, indoline, morpholino, piperidinyl, tetrahydrofuranyl, and the like as well as N-alkoxy-nitrogen containing heterocycles.
The term “saccharide group” refers to an oxidized, reduced or substituted saccharide monoradical covalently attached to the glycopeptide or other compound via any atom of the saccharide moiety, preferably via the aglycone carbon atom. The term includes amino-containing saccharide groups. Representative sacchides include, by way of illustration, hexoses such as D-glucose, D-mannose, D-xylose, D-galactose, vancosamine, 3-desmethyl-vancosamine, 3-epi-vancosamine, 4-epi-vancosamine, acosamine, actinosamine, daunosamine, 3-epi-daunosamine, ristosamine, D-glucamine, N-methyl-D-glucamine, D-glucuronic acid, N-acetyl-D-glucosamine, N-acetyl-D-galactosamine, sialyic acid, iduronic acid, L-fucose, and the like; pentoses such as D-ribose or D-arabinose; ketoses such as D-ribulose or D-fructose; disaccharides such as 2-O-α-L-vancosaminyl)-β-D-gluropyranose, 2-O-(3-desmethyl-α-L-vancosaminyl)-β-D-glucopyranose, sucrose, lactose, or maltose; derivatives such as acetals, amines, acylated, sulfated and phosphorylated sugars; oligosaccharides having from 2 to 10 saccharide units. For the purposes of this definition, these saccharides are referenced using conventional three letter nomenclature and the saccharides can be either in their open or preferably in their pyranose form. The “saccharide group” includes “amino-containing saccharide group” or “amino saccharide,” which refers to a saccharide group having an amino substituent. Representative amino-containing saccharides include L-vancosamine, 3-desmethyl-vancosamine, 3-epi-vancosamine, 4-epi-vancosamine, acosamine, actinosamine, daunosamine, 3-epi-daunosamine, ristosamine, N-methyl-D-gluecamine and the like.
The term “stereoisomer” as it relates to a given compound is well understood in the art, and refers another compound having the same molecular formula, wherein the atoms making up the other compound differ in the way they are oriented in space, but wherein the atoms in the other compound are like the atoms in the given compound with respect to which atoms are joined to which other atoms (e.g. an enantiomer, a diastereomer, or a geometric isomer). See for example, Morrison and Boyde Organic Chemistry, 1983, 4th ed., Allyn and Bacon, Inc., Boston, Mass., page 123.
The term “thiol” refers to the group —SH.
As to any of the above groups which contain one or more substituents, it is understood, of course, that such groups do not contain any substitution or substitution patterns which are sterically impractical and/or synthetically non-feasible. In addition, the compounds of this invention include all stereochemical isomers arising from the substitution of these compounds.
“Cyclodextrin” refers to cyclic molecules containing six or more α-D-glucopyranose units linked at the 1,4 positions by a linkages as in amylose. β-Cyclodextrin or cycloheptaamylose contains seven α-D-glucopyranose units. As used herein, the term “cyclodextrin” also includes cyclodextrin derivatives such as hydroxypropyl and sulfobutyl ether cyclodextrins, and others. Such derivatives are described for example, in U.S. Pat. Nos. 4,727,064 and 5,376,645. Additionally, hydroxypropyl-β-cyclodextrin and sulfobutyl-β-cyclodextrin are commercially available. One preferred cyclodextrin is hydroxypropyl-β-cyclodextrin having a degree of substitution of from about 4.1-5.1 as measured by FTIR Such a cyclodextrin is available from Cerestar (Hammond, Ind., USA) under the name Cavitron™ 82003.
As used herein, an “amino acid” is a natural amino acid residue (e.g. Ala, Arg, Asn, Asp, Cys, Glu, Gln, Gly, His, Hyl, Hyp, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr, and Val) in D or L form, as well as unnatural amino acid (e.g. phosphoserine; phosphotireonine; phosphotyrosine; hydroxyproline; gamma-carboxyglutamate; hippuric acid; octahydroindole-2-carboxylic acid; statine; 1,2,3,4,-tetrahydroisoquinoline-3-carboxylic acid; penicillamine; omithine; citruline; α-methyl-alanine; para-benzoylphenylalanine; phenylglycine; propargylglycine; sarcosine; and tert-butylglycine) residue having one or more open valences. The term also comprises natural and unnatural amino acids bearing amino protecting groups (e.g. acetyl, acyl, trifluoroacetyl, or benzyloxycarbonyl), as well as natural and unnatural amino acids protected at carboxy with protecting groups (e.g. as a (C 1 -C 6 )alkyl phenyl or benzyl ester or amide). Other suitable amino and carboxy protecting groups are known to those skilled in the art (See for example, T. W. Greene, Protecting Groups In Organic Synthesis ; Wiley: New York, 1981; D. Voet, Biochemistry Wiley: New York, 1990; L. Stryer, Biochemistry , (3rd Ed), W.H. Freeman and Co.: New York, 1975; J. March, Advanced Organic Chemistry, Reactions, Mechanisms and Structure , (2nd Ed.), McGraw Hill: New York, 1977; F. Carey and R. Sundberg, Advanced Organic Chemistry, Part B; Reactions and Synthesis , (2nd Ed.), Plenum: New York, 1977; and references cited therein). According to the invention, the amino or carboxy protecting group can also comprise a non-metallic radionuclide (e.g., Fluorine-18, Iodine-123, or Iodine-124).
The term “amino acid” includes alpha amino acids and beta amino acids. The alpha amino acids include monocarboxylic monoamino acids, dicarboxylic monoamino acids, polyamino acids and heterocyclic amino acids. Examples of monocarboxylic monoamino acids include glycine, alpha-phenylglycine, alpha-alanine, serine, valine, norvaline, beta-merceptovaline, threonine, cysteine, leucine, isoleucine, norleucine, N-methylleucine, beta-hydroxy leucine, methionine, phenylalanine, N-methylphenylalanine, pipecolic acid, sarcosine, selenocysteine, tyrosine, 3,5-diiodotyrosine, triiodothyronine, and thyroxine. Examples of monoamino dicarboxylic acids and amides include aspartic acid, beta-methyl aspartic acid, glutamic acid, asparagine, alpha-aminoadipic acid, 4-keto-pipecolic acid, lanthionine, and glutamine. Examples of polyamino acids include omithine, lysine, 6-N-methyllysine, 5-hydroxylysine, desmosine, argmine and cystine. Examples of heterocyclic amino acids include proline, 4-hydroxyproline and histidine, and tryptophan. Examples of other alpha amino acids are gamma-carboxyglutamate and citrulline. The beta amino acids include, for example, beta-alanine.
As used herein, a “peptide” is a sequence of 2 to 25 amino acids (e.g. as defined hereinabove) or peptidic residues having one or more open valences. The sequence may be linear or cyclic. For example, a cyclic peptide can be prepared or may result from the formation of disulfide bridges between two cysteine residues in a sequence. A peptide can be linked through the carboxy terminus, the amino terminus, or through any other convenient point of attachment, such as, for example, through the sulfur of a cysteine. Peptide derivatives can be prepared as disclosed in U.S. Pat. Nos. 4,612,302; 4,853,371; and 4,684,620. Peptide sequences specifically recited herein are written with the amino terminus on the left and the carboxy terminus on the right.
Specific and preferred values listed below for radicals, substituents, and ranges, are for illustration only; they do not exclude other defined values or other values within defined ranges for the radicals and substituents.
A specific value for R 1 is (CH 2 ) 4 , (CH 2 ) 8 , or (CH 2 ) 12 .
A specific value for R 2 is hydrogen, benzyl, or phenethyl. Another specific value for R 2 is benzyl.
A specific value for R 3 is iso-butyl or benzyl.
A specific value for R 4 is (CH 2 ) 4 , (CH 2 ) 6 , (CH 2 ) 8 , or (CH 2 ) 12 .
A specific value for R 5 is p-nitrophenyl.
A specific value for R 6 is (CH 2 ) 3 or (CH 2 ) 2 —O—(CH 2 ) 2 .
A specific value for m is about 0.25 to about 0.75.
A specific value for p is about 0.75 to about 0.25.
A specific value for n is about 75 to about 125.
A specific value for p/(p+m) is about 0.75 to about 0.25.
A specific value for m/(p+m) is about 0.25 to about 0.75.
A specific value for (p+m) is about 0.9 to about 1.1. Another specific value for (p+m) is about 0.75 to about 1.25.
A specific group of compounds of formula (III) are the di-p-tolunesulfonic acid salts of a bis-(L-α-amino acid)-α,ω-alkylene diester.
wherein
each R 3 is independently iso-butyl or benzyl; and
R 4 is (CH 2 ) 4 , (CH 2 ) 6 , (CH 2 ) 8 , or (CH 2 ) 12 .
A specific group of compounds of formula (IV) are the di-p-tolunesulfonic acid salts of L-lysine arylalkyl esters:
wherein
R 2 is benzyl or phenethyl. More specifically, R 2 can be benzyl.
A specific group of compounds of formula (V) are compounds of the formula:
wherein
R 1 is (CH 2 ) 4 , (CH 2 ) 8 , or (CH 2 ) 12 ; and
R 5 is p-nitrophenyl.
For example, a specific group of compounds of formula (V) are di-p-nitrophenyl adipate, di-p-nitrophenyl sebacinate, and di-p-nitrophenyl dodecyldicarboxylate.
A specific group of compounds of formula (X) are compounds of the formula:
wherein
R 5 is p-nitrophenyl; and
R 6 is (CH 2 ) 3 or (CH 2 ) 2 —O—(CH 2 ) 2 .
For example, a specific group of compounds of formula (X) are 1,3-bis (4-nitro-phenoxycarbonyloxy)propane and 2,2′-bis-4-(nitrophenoxycarbonyloxy)ethylether.
In cases where compounds (e.g, starting materials) are sufficiently basic or acidic to form stable nontoxic acid or base salts, the compounds can exist as the acceptable salt. Examples of acceptable salts are organic acid addition salts formed with acids which form an acceptable anion, for example, tosylate, methanesulfonate, acetate, citrate, malonate, tatarate, succinate, benzoate, ascorbate, α-ketoglutarate, and α-glycerophosphate. Suitable inorganic salts may also exist, including hydrochloride, sulfate, nitrate, bicarbonate, and carbonate salts.
Acceptable salts may be obtained by using standard procedures that are well known in the art for example by reacting a sufficiently basic compound such as an amine with a suitable acid affording an acceptable anion. Alkali metal (for example, sodium, potassium or lithium) or alkaline earth metal (for example calcium) salts of carboxylic acids can also be made.
Processes for preparing polymers of the present invention (e.g., polymers of formula (VII) and polymers of formula (XI)) are provided as further embodiments of the invention and are illustrated by the procedures herein below in which the meanings of the generic radicals are as given above unless otherwise qualified.
A polymer of formula (VII) can include one or more subunits of formula (I) and one or more subunits of formula (II). As such, a polymer of formula (VII) can be prepared from a compound of formula (II), from a compound of formula (IV), and from a compound of formula (V). Specifically, a polymer of formula (VII) can be prepared by contacting a compound of formula (III), a compound of formula (IV), and a compound of formula (V) under suitable conditions to provide a polymer of formula (VII).
The compounds of formula (III), (IV), and (V) can be contacted in the presence of a solvent. Any suitable solvent can be employed. When the compounds of formula (III), (IV), and (V) are contacted in the presence of a solvent, the compounds of formula (III), (IV), and (V) are preferably soluble in the solvent. One exemplary suitable solvent is N,N-dimethylacetamide.
The compounds of formula (III), (IV), and (V) can be contacted in the presence of a base. Any suitable base can be employed. When the compounds of formula (III), (IV), and (V) are contacted in the presence of a base, the base will preferably adjust the initial pH of the reaction mixture (i.e., the solution including the compounds of formula (III), (IV), and (V)) above about 7. The base is useful to yield the free amines of the compound of formula (III) and the compound of formula (IV). One exemplary suitable base is triethylamine.
The compounds of formula (III), (IV), and (V) can be contacted for a period of time sufficient to provide the polymer of formula (VII). For example, the period of time can be from about 1 hour to about 48 hours, inclusive. Preferably, the period of time can be from about 5 hours to about 30 hours, inclusive. More preferably, the period of time can be from about 10 hours to about 24 hours, inclusive.
The compounds of formula (III), (IV), and (V) can be contacted at a temperature sufficient to provide the polymer of formula (VII). For example, the temperature can be from the freezing point of the liquid reaction mixture (e.g., the solvent, base, and the compounds of formula (III), (IV), and (V)) up to about the reflux temperature of the reaction mixture. Preferably, the temperature can be from about 25° C. to about 150° C. More preferably, the temperature can be from about 50° C. to about 100° C.
A polymer of formula (XI) can include one or more subunits of formula (VIII) and one or more subunits of formula (IX). As such, a polymer of formula (XI) can be prepared from a compound of formula (III), from a compound of formula (IV), and from a compound of formula (X). Specifically, a polymer of formula (XI) can be prepared by contacting a compound of formula (III), a compound of formula (IV), and a compound of formula (X) under suitable conditions to provide a polymer of formula (XI).
The compounds of formula (III), (IV), and (X) can be contacted in the presence of a solvent. Any suitable solvent can be employed. When the compounds of formula (III), (IV), and (X) are contacted in the presence of a solvent, the compounds of formula (III), (IV), and (X) are preferably soluble in the solvent One exemplary suitable solvent is N,N-dimethylacetamide.
The compounds of formula (III), (IV), and (X) can be contacted in the presence of a base. Any suitable base can be employed. When the compounds of formula (III), (IV), and (X) are contacted in the presence of abase, the base will preferably adjust the initial pH of tie reaction mixture (i.e., the solution including the compounds of formula (III), (IV), and (X)) above about 7. The base is useful to yield the free amines of the compound of formula (III) and the compound of formula (IV). One exemplary suitable base is triethylamine.
The compounds of formula (III), (IV), and (X) can be contacted for a period of time sufficient to provide the polymer of formula (VII). For example, the period of time can be from about 1 hour to about 48 hours, inclusive. Preferably, the period of time can be from about 5 hours to about 30 hours, inclusive. More preferably, the period of time can be from about 10 hours to about 24 hours, inclusive.
The compounds of formula (III), (IV), and (X) can be contacted at a temperature sufficient to provide the polymer of formula (VII). For example, the temperature can be from about the freezing point of the liquid reaction mixture (e.g.,the solvent, base, and the compounds of formula (III), (IV), and (X)) up to about the reflux temperature of the reaction mixture. Preferably, the temperature can be from about 25° C. to about 150° C. More preferably, the temperature can be from about 50° C. to about 100° C.
Polymer and Drug
A polymer of the present invention can include one or more drugs. In one embodiment, a polymer of the present invention can be physically intermixed with one or more drugs. In another embodiment, a polymer of the present invention can be linked to one or more drugs, either directly or through a linker. In another embodiment, a polymer of the present invention can be linked to one or more drugs, either directly or through a linker, and the resulting polymer can be physically intermixed with one or more drugs.
As used herein, a “polymer of the present invention” includes a compound of formula (VII), a compound of formula (XI) or a combination thereof.
Polymer/Drug Linkage
The present invention provides a polymer of the present invention (e.g., a compound of formula (VII) or a compound of formula (XI)) directly linked to one or more drugs. In such an embodiment, the residues of the polymer can be linked to the residues of the one or more drugs. For example, one residue of the polymer can be directly linked to one residue of the drug. The polymer and the drug can each have one open valence. Alternatively, more than one drug can be directly linked to the polymer. In such an embodiment, the residue of each drug can be linked to a corresponding residue of the polymer. As such, the number of residues of the one or more drugs can correspond to the number of open valences on the residue of the polymer.
As used herein, a “residue of a polymer of the present invention” refers to a radical of a polymer of the present invention having one or more open valences. Any synthetically feasible atom, atoms, or functional group of the polymer (e.g., on the polymer backbone or pendant group) of the present invention can be removed to provide the open valence, provided bioactivity is substantially retained when the radical is attached to a residue of a drug. Additionally, any synthetically feasible functional group (e.g., carboxyl) can be created on the polymer (e.g., on the polymer backbone or pendant group) to provide the open valence, provided bioactivity is substantially retained when the radical is attached to a residue of a drug. Based on the linkage that is desired, one skilled in the art can select suitably functionalized starting materials that can be derived from the polymer of the present invention using procedures that are known in the art.
As used herein, a “residue of a compound of formula (VII)” refers to a radical of a compound of formula (VII) having one or more open valences. Any synthetically feasible atom, atoms, or functional group of the compound of formula (VII) (e.g., on the polymer backbone or pendant group) can be removed to provide the open valence, provided bioactivity is substantially retained when the radical is attached to a residue of a drug. Additionally, any synthetically feasible functional group (e.g., carboxyl) can be created on the compound of formula (VII) (e.g., on the polymer backbone or pendant group) to provide the open valence, provided bioactivity is substantially retained when the radical is attached to a residue of a drug. Based on the linkage that is desired, one skilled in the art can select suitably functionalized starting materials that can be derived from the compound of formula (VII) using procedures that are known in the art.
As used herein, a “residue of a compound of formula (XI)” refers to a radical of a compound of formula (XI) having one or more open valences. Any synthetically feasible atom, atoms, or functional group of the compound of formula (XI) (e.g., on the polymer backbone or pendant group) can be removed to provide the open valence, provided bioactivity is substantially retained when the radical is attached to a residue of a drug. Additionally, any synthetically feasible functional group (e.g., carboxyl) can be created on the compound of formula (XI) (e.g., on the polymer backbone or pendant group) to provide the open valence, provided bioactivity is substantially retained when the radical is attached to a residue of a drug. Based on the linkage that is desired, one skilled in the art can select suitably functionalized starting materials that can be derived from the compound of formula (XI) using procedures that are known in the art.
The residue of a drug can be linked to the residue of a compound of formula (VII) or (XI) through an amide (e.g., —N(R)C(═O)— or —C(═O)N(R)—), ester (e.g., —OC(═O)— or —C(═O)O—), ether (e.g., —O—), amino (e.g., —N(R)—), ketone (e.g., —C(═O)—), thioether (e.g., —S—), sulfinyl (e.g., —S(O)—), sulfonyl (e.g., —S(O) 2 —), disulfide (e.g., —S—S—), or a direct (e.g., C—C bond) linkage, wherein each R is independently H or (C 1 -C 6 )alkyl. Such a linkage can be formed from suitably functionalized starting materials using synthetic procedures that are known in the art. Based on the linkage that is desired, one skilled in the art can select suitably functional staring materials that can be derived from a residue of a compound of formula (VII) or (XI) and from a given residue of a drug using procedures that are known in the art the residue of the drug can be directly linked to any synthetically feasible position on the residue of a compound of formula (VII) or (XI). Additionally, the invention also provides compounds having more than one residue of a drug or drugs directly linked to a compound of formula (VII) or (XI).
One or more drugs can be linked directly to the polymer. Specifically, the residue of each of the drugs can each be directly linked to the residue of the polymer. Any suitable number of drugs (i.e., residues thereof) can be directly linked to the polymer (i.e., residue thereof). The number of drugs that can be directly linked to the polymer can typically depend upon the molecular weight of the polymer. For example, for a compound of formula (VII), wherein n is about 50 to about 150, up to about 450 drugs (i.e., residues thereof) can be directly linked to the polymer (i.e., residue thereof), up to about 300 drugs (i.e., residues thereof) can be directly linked to the polymer (i.e., residue thereof), or up to about 150 drugs (i.e., residues thereof) can be directly linked to the polymer (i.e., residue thereof). Likewise, for a compound of formula (XI), wherein n is about 50 to about 150, up to about 450 drugs (i.e., residues thereof) can be directly linked to the polymer (i.e., residue thereof), up to about 300 drugs (i.e., residues thereof) can be directly linked to the polymer (i.e., residue thereof), or up to about 150 drugs (i.e., residues thereof) can be directly linked to the polymer (i.e., residue thereof).
The residue of a polymer of the present invention, the residue of a compound of formula (VII), and/or the residue of a compound of formula (XI) can be formed employing any suitable reagents and reaction conditions. Suitable reagents and reaction conditions are disclosed, e.g., in Advanced Organic Chemistry, Part B; Reactions and Synthesis , Second Edition, Carey and Sundberg (1983); Advanced Organic Chemistry, Reactions, Mechanisms, and Structure , Second Edition, March (1977); and Comprehensive Organic Transformations , Second Edition, Larock (1999).
In one embodiment of the present invention, a polymer (i.e., residue thereof) of the present invention can be linked to the drug (i.e., residue thereof) via the carboxyl group (e.g., COOR 2 ) of the polymer. Specifically, a compound of formula (VII), wherein R 2 is independently hydrogen, or (C 6 -C 10 )aryl(C 1 -C 6 )alkyl; a compound of formula (XI), wherein R 2 is independently hydrogen, or (C 6 -C 10 )aryl(C 1 -C 6 )alkyl; or a combination thereof, can react with an amino functional group of the drug or a hydroxyl functional group of the drug, to provide a Polymer/Drug having an amide linkage or a Polymer/Drug having a carboxylic ester linkage, respectively. In another embodiment, the carboxyl group of the polymer can be transformed into an acyl halide or an acyl anhydride.
Drug
As used herein, a “drug” refers to a therapeutic agent or a diagnostic agent and includes any substance, other than food, used in the prevention, diagnosis, alleviation, treatment, or cure of a disease. Stedman's Medical Dictionary 25 th Edition, Illustrated (1990) p. 486. The substance can be taken by mouth; injected into a muscle, the ski, a blood vessel, or a cavity of the body; or topically applied. Mosby's Medical, Nursing & Allied Health Dictionary , Fifth Edition, (1998) p. 516. The drug can include any substance disclosed in at least one of: The Merck Index, 12 th Edition (1996); Concise Dictionary of Biomedicine and Molecular Biology . Pei-Show Juo, (1996); U.S. Pharmacopeia Dictionary 2000 Edition; and Physician's Desk Reference, 2001 Edition.
Specifically, the drug can include, but is not limited to, one or more: polynucleotides, polypeptides, oligonucleotides, gene therapy agents, nucleotide analogs, nucleoside analogs, polynucleic acid decoys, therapeutic antibodies abeiximab, anti-inflammatory agents, blood modifiers, anti-platelet agents, anti-coagulation agents, immune suppressive agents, anti-neoplastic agents, anticancer agents, anti-cell proliferation agents, and nitric oxide releasing agents.
The polynucleotide can include deoxyribonucleic acid (DNA), ribonucleic acid (RNA), double stranded DNA, double stranded RNA, duplex DNA/RNA, antisense polynucleotides, functional RNA or a combination thereof In one embodiment, the polynucleotide can be RNA. In another embodiment, the polynucleotide can be DNA. In another embodiment, the polynucleotide can be an antisense polynucleotide. In another embodiment, the polynucleotide can be a sense polynucleotide. In another embodiment, the polynucleotide can include at least one nucleotide analog. In another embodiment, the polynucleotide can include a phosphodiester linked 3′-5′ and 5′-3′ polynucleotide backbone. Alternatively, the polynucleotide can include non-phosphodiester linkages, such as phosphotioate type, phosphoramidate and peptide-nucleotide backbones. In another embodiment, moieties can be linked to the backbone sugars of the polynucleotide. Methods of creating such linkages are well known to those of skill in the art.
The polynucleotide can be a single-stranded polynucleotide or a double-stranded polynucleotide. The polynucleotide can have any suitable length. Specifically, the polynucleotide can be about 2 to about 5,000 nucleotides in length, inclusive; about 2 to about 1000 nucleotides in length inclusive; about 2 to about 100 nucleotides in length, inclusive; or about 2 to about 10 nucleotides in length, inclusive.
An antisense polynucleotide is typically a polynucleotide that is complimentary to an mRNA, which encodes a target protein. For example, the mRNA can encode a cancer promoting protein i.e., the product of an oncogene. The antisense polynucleotide is complimentary to the single stranded mRNA and will form a duplex and thereby inhibit expression of the target gene, i.e., will inhibit expression of the oncogene. The antisense polynucleotides of the invention can form a duplex with the mRNA encoding a target protein and will disallow expression of the target protein.
A “functional RNA” refers to a ribozyme or other RNA that is not translated.
A “polynucleic acid decoy” is a polynucleic acid which inhibits the activity of a cellular factor upon binding of the cellular factor to the polynucleic acid decoy. The polynucleic acid decoy contains the binding site for the cellular factor. Examples of cellular factors include, but are not limited to, transcription factors, polymerases and ribosomes. An example of a polynucleic acid decoy for use as a transcription factor decoy will be a double stranded polynucleic acid containing the binding site for the transcription factor. Alternatively, the polynucleic acid decoy for a transcription factor can be a single stranded nucleic acid that hybridizes to itself to form a snap-back duplex containing the binding site for the target transcription factor. An example of a transcription factor decoy is the E2F decoy. E2F plays role in transcription of genes that are involved with cell-cycle regulation and that cause cells to proliferate. Controlling B2F allows regulation of cellular proliferation. For example, after injury (e.g., angioplasty, surge, stenting) smooth muscle cells proliferate in response to the injury. Proliferation may cause restenosis of the treated area (closure of an artery though cellular proliferation). Therefore, modulation of E2F activity allows control of cell proliferation and can be used to decrease proliferation and avoid closure of an artery. Examples of other such polynucleic acid decoys and target proteins include, but are not limited to, promoter sequences for inhibiting polymerases and ribosome binding sequences for inhibiting ribosomes. It is understood that the invention includes polynucleic acid decoys constructed to inhibit any target cellular factor.
A “gene therapy agent” refers to an agent that causes expression of a gene product in a target cell through introduction of a gene into the target cell followed by expression. An example of such a gene therapy agent would be a genetic construct that causes expression of a protein, such as insulin, when introduced into a cell. Alternatively, a gene therapy agent can decrease expression of a gene in a target cell. An example of such a gene therapy agent would be the introduction of a polynucleic acid segment into a cell that would integrate into a target gene and disrupt expression of the gene. Examples of such agents include viruses and polynucleotides that are able to disrupt a gene through homologous recombination. Methods of introducing and disrupting genes with cells are well known to those of skill in the art.
An oligonucleotide of the invention can have any suitable length Specifically, the oligonucleotide can be about 2 to about 100 nucleotides in length, inclusive; up to about 20 nucleotides in length, inclusive; or about 15 to about 30 nucleotides in length, inclusive. The oligonucleotide can be single-stranded or double-stranded. In one embodiment, the oligonucleotide can be single stranded. The oligonucleotide can be DNA or RNA. In one embodiment, the oligonucleotide can be DNA. In one embodiment, the oligonucleotide can be synthesized according to commonly known chemical methods. In another embodiment, the oligonucleotide can be obtained from a commercial supplier. The oligonucleotide can include, but is not limited to, at least one nucleotide analog, such as bromo derivatives, azido derivatives, fluorescent derivatives or a combination thereof. Nucleotide analogs are well known to those of skill in the art. The oligonucleotide can include a chain terminator. The oligonucleotide can also be used, e.g., as a cross linking reagent or a fluorescent tag. Many common linkages can be employed to couple an oligonucleotide of the invention to another moiety, e.g., phosphate, hydroxyl, etc. Additionally, a moiety may be linked to the oligonucleotide through a nucleotide analog incorporated into the oligonucleotide. In another embodiment, the oligonucleotide can include a phosphodiester linked 3′-5′ and 5′-3′ oligonucleotide backbone. Alternatively, the oligonucleotide can include non-phosphodiester linkages, such as phosphotioate type, phosphoramidate and peptide-nucleotide backbones. In another embodiment, moieties can be linked to the backbone sugars of the oligonucleotide. Methods of creating such linkages are well known to those of skill in the art.
Nucleotide and nucleoside analogues are well known on the art. Examples of such nucleoside analogs include, but are not limited to, Cytovene® (Roche Laboratories), Epivir® (Glaxo Wellcome), Gemzar® (Lilly), Hivid® (Roche Laboratories), Rebetron® (Schering), Videx® Bristol-Myers Squibb), Zerit® (Bristol-Myers Squibb), and Zovirax® (Glaxo Wellcome). See, Physician's Desk Reference 2001 Edition.
Polypeptides of the invention can have any suitable length. Specifically, the polypeptides can be about 2 to about 5,000 amino acids in length, inclusive; about 2 to about 2,000 amino acids in length, inclusive; about 2 to about 1,000 amino acids in length, inclusive; or about 2 to about 100 amino acids in length, inclusive.
The polypeptides of the invention can also include “Peptide mimetics”. Peptide analogs are commonly used in the pharmaceutical industry as non-peptide drugs with properties analogous to those of the template peptide. These types of non-peptide compound are termed “peptide mimetics” or “peptide mimetics”. Fauchere, J. (1986) Adv. Drug Res. 15:29; Veber and Freidinger (1985) TINS p. 392; and Evans et al. (1987) J. Med. Chem., 30: 1229; and are usually developed with the aid of computerized molecular modeling. Generally, peptidomimetics are structurally similar to a paradigm polypeptide (i.e., a polypeptide that has a biochemical property or pharmacological activity), but have one or more peptide linkages optionally replaced by a linkage selected from the group consisting of: —CH 2 NH—, —CH 2 S—, CH 2 —CH 2 —, —CH═CH— (cis and trans), —COCH 2 —, —CH(OH)CH 2 —, and —CH 2 SO—, by methods known in the art and further described in the following references: Spatola, A. F. in “Chemistry and Biochemistry of Amino Acids, Peptides, and Proteins,” B. Weinstein, eds., Marcel Dekker, New York, p. 267 (1983); Spatola, A F., Vega Data (March 1983), Vol. 1, Issue 3, “Peptide Backbone Modifications” (general review); Morley, J. S., Trends. Pharm. Sci., (1980) pp. 463-468 (general review); Hudson, D. et al., Int J. Pept. Prot. Res. , (1979) 14:177-185 (—CH 2 NH—, CH 2 CH 2 —); Spatola, A. F. et al., Life Sci. . (1986) 38:1243-1249 (—CH 2 —S—); Hann, M. M., J. Chem. Soc. Perkin Trans I (1982) 307-314 (—CH═CH—, cis and trans); Almquist, R. G. et al., J. Med. Chem., ( 1980) 23:1392-1398 (—COCH 2 —); Jennings-White, C. et al., Tetrahedron Lett ., (1982) 23:2533 (—COCH 2 —) Szelke, M. et al., European Appln., EP 45665 (1982) CA: 97:39405 (1982) (—CH(OH)CH 2 —); Holladay, M. W. et al., Tetrahedron Lett ., (1983) 24:4401-4404 (—C(OH)CH 2 —); and Hruby, V. J., Life Sci ., (1982) 31:189-199 (—CH 2 —S—). Such peptide mimetics may have significant advantages over polypeptide embodiments, including, for example: more economical production, greater chemical stability, enhanced pharmacological properties (half-life, absorption, potency, efficacy, etc.), altered specificity (e.g., a broad-spectrum of biological activities), reduced antigenicity, and others.
Additionally, substitution of one or more amino acids within a polypeptide with a D-amino acid of the same type (e.g., D-lysine in place of L-lysine) may be used to generate more stable polypeptides and polypeptides resistant to endogenous proteases.
In one embodiment, the polypeptide can be an antibody. Examples of such antibodies include single-chain antibodies, chimeric antibodies, monoclonal antibodies, polyclonal antibodies, antibody fragments, Fab fragments, IgA, IgG, IgM IgD, IgE and humanized antibodies. In one embodiment, the antibody can bind to a cell adhesion molecule, such as a cadherin, integrin or selectin. In another embodiment, the antibody can bind to an extracellular matrix molecule, such as collagen, elastin, fibronectin or laminin. In still another embodiment, the antibody can bind to a receptor, such as an adrenergic receptor, B-cell receptor, complement receptor, cholinergic receptor, estrogen receptor, insulin receptor, low-density lipoprotein receptor, growth factor receptor or T-cell receptor. Antibodies of the invention can also bind to platelet aggregation factors (e.g., fibrinogen), cell proliferation factors (e.g., growth factors and cytolines), and blood clotting factors (e.g., fibrinogen). In another embodiment, an antibody can be conjugated to an active agent, such as a toxin. In another embodiment, the antibody can be Abciximab (ReoPro(R)). Abeiximab is an Fab fragment of a chimeric antibody that binds to beta(3) integrins. Abciximab is specific for platelet glycoprotein IIb/IIIa receptors, e.g., on blood cells. Human aortic smooth muscle cells express alpha(v)beta(3) integrins on their surface. Treating beta(3) expressing smooth muscle cells may prohibit adhesion of other cells and decrease cellular migration or proliferation, thus reducing restinosis following percutaneous coronary interventions (CPI) e.g., stenosis, angioplasty, stenting. Abciximab also inhibits aggregation of blood platelets.
In one embodiment, the peptide can be a glycopeptide. “Glycopeptide” refers to oligopeptide (e.g. heptapeptide) antibiotics, characterized by a multi-ring peptide core optionally substituted with saccharide groups, such as vancomycin. Examples of glycopeptides included in this definition may be found in “Glycopeptides Classification, Occurrence, and Discovery”, by Raymond C. Rao and Louise W. Crandall, (“Drugs and the Pharmaceutical Sciences”Volume 63, edited by Ramakrishnan Nagarajan, published by Marcal Dekker, Inc.). Additional examples of glycopeptides are disclosed in U.S. Pat. Nos. 4,639,433; 4,643,987; 4,497,802; 4,698,327; 5,591,714; 5,840,684; and 5,843,889; in EP 0 802 199; EP 0 801 075; EP 0 667 353; WO 97/28812; WO 97/38702; WO 98/52589; WO 98/52592; and in J. Amer. Chem. Soc., 1996, 118, 13107-13108 ; J. Amer. Chem. Soc., 1997, 119, 12041-12047; and J. Amer. Chem. Soc., 1994, 116,4573-4590. Representative glycopeptides include those identified as A477, A35512, A40926, A41030, A42867, A47934, A80407, A82846, A83850 A84575, AB65, Actaplanin, Actinoidin, Ardacin, Avoparcin, Azureomycin, Balhimycin, Chloroorientiein, Chloropolysporin, Decaplanin, -demethylvancomycin, Bremomycin, Galacardin, Helvecardin, Izupeptin, Kibdelin, LL-AM374, Mannopeptin, MM45289, MM47756, MM47761, MM49721, MM47766, MM55260, MM55266, MM55270, MM56597, MMS6598, OA-7653, Orenticin, Parvodicin, Ristocetin, Ristomycin, Synmonicin, Teicoplanin, UK-68597, UK-69542, UK-72051, Vancomycin, and the like. The term “glycopeptide” or “glycopeptide antibiotic” as used herein is also intended to include the general class of glycopeptides disclosed above on which the sugar moiety is absent, i.e. the aglycone series of glycopeptides. For example, removal of the disaccharide moiety appended to the phenol on vancomycin by mild hydrolysis gives vancomycin aglycone. Also included within the scope of the term “glycopeptide antibiotics” are synthetic derivatives of the general class of glycopeptides disclosed above, included alkylated and acylated derivatives. Additionally, within the scope of this term are glycopeptides that have been further appended with additional saccharide residues, especially aminoglycosides, in a manner similar to vancosamine.
The term “lipidated glycopeptide” refers specifically to those glycopeptide antibiotics which have been-synthetically modified to contain a lipid substituent. As used herein, the term “lipid substituent” refers to any substituent contains 5 or more carbon atoms, preferably, 10 to 40 carbon atoms. The lipid substituent may optionally contain from 1 to 6 heteroatoms selected from halo, oxygen, nitrogen, sulfur and phosphorous. Lipidated glycopeptide antibiotics are well-known in the art See, for example, in U.S. Pat. Nos. 5,840,684, 5,843,889, 5,916,873, 5,919,756, 5,952,310, 5,977,062, 5,977,063, EP 667,353, WO 98/52589, WO 99/56760, WO 00/04044, WO 00/39156, the disclosures of which are incorporated herein by reference in their entirety.
Anti-inflammatory agents include, e.g., analgesics (e.g., NSAIDS and salicylates), antirheumatic agents, gastrointestinal agents, gout preparations, hormones (glucocorticoids), nasal preparations, ophthalmic preparations, otic preparations (e.g., antibiotic and steroid combinations), respiratory agents, and skin & mucous membrane agents. See, Physician's Desk Reference, 2001 Edition. Specifically, the anti-inflammatory agent can include dexamethasone, which is chemically designated as (11β, 16α)-9-fluoro-11,17,21-trihydroxy-16-methylpregna-1,4diene-3,20-dione. Alternatively, the anti-inflammatory agent can include sirolimus (rapamycin), which is a triene macrolide antibiotic isolated from Streptomyces hygroscopicus.
Anti-platelet or anticoagulation agents include, e.g., Coumadin® (DuPont), Fragmin® (Pharmacia & Upjohn), Heparin® (Wyeth-Ayerst), Lovenox®, Normiflo®, Orgaran® (Organon), Aggrastat® (Merck), Agrylin® (Roberts), Ecotrin® (Smithkline Beechamn), Flolan® (Glaxo Wellcome), Halfprin® (Kramer), Integrillin® (COR Therapeutics), Integrillin® (Key), Persantine® (Boehringer Ingelheim), Plavix® (Bristol-Myers Squibb), ReoPro® (Centecor), Ticlid® (Roche), Abbokinase® (Abbtt), Activase® (Genentech), Eminase® (Roberts), and Strepase® (Astra). See, Physician's Desk Reference, 2001 Edition. Specifically, the anti-platelet or anti-coagulation agent can include trapidil (avantrin), cilostazol, heparin, hirudin, or ilprost.
Trapidil is chemically designated as N,N-dimethyl-5-methyl-[1,2,4]triazolo[1,-5-a]pyrimidin4-amine.
Cilostazol is chemically designated as 6-[4-(1-cyclohexyl-1H-tetrazol-5-yl)-butoxy]-3,4-dihydro-2(1H)-quinolinone.
Heparin is a glycosaminoglycan with anticoagulant activity; a heterogeneous mixture of vatiably sulfonated polysaccharide chains composed of repeating units of D-glucosamine and either L-iduronic or D-glucuronic acids.
Hirudin is an anticoagulant protein extracted from leeches, e.g., Hirudo medicinalis.
Iloprost is chemically designated as 5-[Hexahydro-5-hydroxy-4-(3-hydroxy-4-methyl-1-octen-6-ynyl)-2(1H)-pentalenylidene]pentanoic acid.
The immune suppressive agent can include, e.g., Azathioprine® (Roxane), BayRho-D® (Bayer Biological), CellCept® (Roche Laboratories), Imuran® (Glaxo Wellcome), MiCRhoGAM® (Ortho-Clinical Diagnostics), Neoran® (Novarts), Orthoclone OKT3® (Ortho Biotech), Prograf® (Fujisawa), PhoGAM® (Ortho-Clinical Diagnostics), Sandimmune® (Novartis), Simulect® (Novartis), and Zenapax® (Roche Laboratories).
Specifically, the immune suppressive agent can include rapamycin or thalidomide.
Rapamycin is a triene macrolide isolated from Streptomyces hygroscopicus.
Thalidomide is chemically designated as 2-(2,6-dioxo-3-piperidinyl)-1H-iso-indole-1,3(2H)-dione.
Anti-cancer or anti-cell proliferation agents include, e.g., nucleotide and nucleoside analogs, such as 2-chloro-deoxyadenosine, adjunct antineoplastic agents, alkylating agents, nitrogen mustards, nitrosoureas, antibiotics, antimetabolites, hormonal agonists/antagonists, androgens, antiandrogens, antiestrogens, estrogen & nitrogen mustard combinations, gonadotropin releasing hotmone (GNRH) analogues, progestrins, immunomodulators, miscellaneous antineoplastics, photosensitizing agents, and skin & mucous membrane agents. See, Physician's Desk Reference. 2001 Edition.
Suitable adjunct antineoplastic agents include Anzemet® (Hoeschst Marion Roussel), Aredia® (Novartis), Didronel® (MGI), Diflucan® Pfizer), Epogen® (Amgen), Ergamisol® (Janssen), Ethyol® (Alza), Kytril® (SmithKline Beecham), Leucovorin® (Immunex), Leucovorin® (Glaxo Wellcome), Leucovorin® (Astra), Leukine® (Immunex), Marinol® (Roxane), Mesnex® (Bristol-Myers Squibb Oncology/Immunology, Neupogen (Amgen), Procrit® (Ortho Biotech), Salagen® (MGI), Sandostatin® (Novartis), Zinecard® (Pharmacia & Upjohn), Zofran® (Glaxo Wellcome) and Zyloprim® (Glaxo Wellcome).
Suitable miscellaneous allylating agents include Myleran® (Glaxo Wellcome), Paraplatin® (Bristol-Myers Squibb Oncology/Immunology), Platinol® (Bristol-Myers Squibb Oncology/Immunology) and Thioplex® (Immunex).
Suitable nitrogen mustards include Alkeran® (Glaxo Wellcome), Cytoxan® (Bristol-Myers Squibb Oncology/Immunology), Ifex® (Bristol-Myers Squibb Oncology/Immunology), Leukeran® (Glaxo Wellcome) and Mustargen® Merck).
Suitable nitrosoureas include BiCNU® (Bristol-Myers Squibb Oncology/Immunology), CeeNU® (Bristol-Myers Squibb Oncology/Immunology), Gliadel® (Rhône-Poulenc Rover) and Zanosar® (Pharmacia & Upjohn).
Suitable antibiotics include Adriamycin PFS/RDF® (Pharmacia & Upjohn), Blenoxane® (Bristol-Myers Squibb Oncology/Immunology), Cerubidine® (Bedford), Cosmegen® (Merck), DaunoXome® (NeXstar), Doxil® (Sequus), Doxorubicin Hydrochloride® (Astra), Idamycin® PFS Pharmacia & Upjohn), Mithracin® (Bayer), Mitamycin® (Bristol-Myers Squibb Oncology/Immunology), Nipen® (SuperGen), Novantrone® (Immunex) and Rubex® (Bristol-Myers Squibb Oncology/Immunology).
Suitable antimetabolites include Cytostar-U® (Pharmacia & Upjohn), Fludara® (Berlex), Sterile FUDR® (Roche Laboratories), Leustatin® (Ortho Biotech), Methotrexate® (Immunex), Parinethol® (Glaxo Wellcome), Thioguanine® (Glaxo Wellcome) and Xeloda® (Roche Laboratories).
Suitable androgens include Nilandron® (Hoechst Marion Roussel) and Teslac® (Bristol-Myers Squibb Oncology/Immunology).
Suitable antiandrogens include Casodex® (Zeneca) and Eulexin® (Schering).
Suitable antiestrogens include Arimidex® (Zeneca), Fareston® (Schering), Femara® (Novartis) and Nolvadex® (Zeneca).
Suitable estrogen & nitrogen mustard combinations include Emcyt® (Pharmacia & Upjohn).
Suitable estrogens include Estrac® (Bristol-Myers Squibb) and Estrab® (Solvay).
Suitable gonadotropin releasing hormone (GNRH) analogues include Leupron Depot® (TAP) and Zoladex® (Zeneca).
Suitable progestins include Depo-Provera® (Pharmacia & Upjohn) and Megace® (Bristol-Myers Squibb Oncology/Immunology).
Suitable immunomodulators include Erganisol® (Janssen) and Proleukin® (Chiron Corporation).
Suitable miscellaneous antineoplastics include Camptosar® (Pharmacia & Upjohn), Celestone® (Schering), DTIC-Dome® (Bayer), Elspar® (Merck), Etopophos® (Bistol-Myers Squibb Oncology/Immunology), Etopoxide® (Astra), Gemzar® (Lilly), Hexalen® (U.S. Bioscience), Hycantin® (SmithKline Beecham), Hydrea® (Bristol-Myers Squibb Oncology/Immunology), Hydroxyurea® (Roxane), Intron A® (Schering), Lysodren® (Bristol-Myers Squibb Oncology/Immunology), Navelbine® (Glaxo Wellcome), Oncaspar® (Rhône-Poulenc Rover), Oncovin® (Lilly), Proleukin® (Chiron Corporation), Rituxan® (IDEC), Rituxan® (Genentech), Roferon-A® (Roche Laboratories), Taxol® (Bristol-Myers Squibb Oncology/Immunology), Taxotere® (Rhône-Poulenc Rover), TheraCys® (Pasteur Mérieux Connaught), Tice BCG® (Organon), Velban® (Lilly), VePesid® (Bristol-Myers Squibb Oncology/Immunology), Vesanoid® (Roche Laboratories) and Vumon® (Bristol-Myers Squibb Oncology/Immunology).
Suitable photosensitizing agents include Photofrin® (Sanofi).
Specifically, the anti-cancer or anti-cell proliferation agent can include Taxol® (paclitaxol), a niticoxide like compound, or NicOx (NCX-4016).
Taxol® (paclitaxol) is chemically designated as 5β,20-Epoxy-1,2α,4,7β,10β,13α-hexahydroxytax-11-en-9-one 4,10-diacetate 2-benzoate 13-ester with (2R,3S)-N-benzoyl-3-phenylisoserine.
A niticoxide like compound includes any compound (e.g., polymer) to which is bound a nitric oxide releasing functional group. Suitable niticoxide like compounds are disclosed, e.g., in U.S. Pat. No. 5,650,447 and S-nitrosothiol derivative (adduct) of bovine or human serum albumin. See, e.g., Inhibition of neointimal proliferation in rabbits after vascular injury by a single treatment with a protein adduct of nitric oxide ; David marks et al J. Clin. Invest . (1995);96:2630-2638.
NCX-4016 is chemically designated as 2-acetoxy-benzoate 2-(nitroxymethyl)-phenyl ester, and is an antithrombitic agent.
It is appreciated that those skilled in the art understand that the drug useful in the present invention is the biologically active substance present in any of the drugs or agents disclosed above. For example, Taxol® (paclitaxol) is typically available as an injectable, slightly yellow, viscous solution. The drug, however, is a crystalline powder with the chemical name 5β,20-Epoxy-1,2α,4,7β,10β,13α-hexahydroxytax-11-en-9-one 4,10-diacetate 2-benzoate 13-ester with (2R,3S)-N-benzoyl-3-phenylisoserine. Physician's Desk Reference ( PDR ) Medical Economics Company (Montvale, N.J.), (53rd Ed.), pp. 1059-1067.
As used herein, a “residue of a drug” is a radical of a drug having one or more open valences. Any synthetically feasible atom or atoms of the drug can be removed to provide the open valence, provided bioactivity is substantially retained when the radical is attached to a residue of compound of formula (VII) or (XI). Based on the linkage that is desired, one skilled in the art can select suitably functionalized starting materials that can be derived from a drug using procedures that are known in the art.
The residue of a drug can be formed employing any suitable reagents and reaction conditions. Suitable reagents and reaction conditions are disclosed, e.g;, in Advanced Organic Chemistry, Part B: Reactions and Synthesis . Second Edition, Carey and Sundberg (1983); Advanced Organic Chemistry, Reactions, Mechanisms, and Structure , Second Edition, March (1977); and Comprehensive Organic Transformations , Second Edition, Larock (1999).
The polymer/drug linkage can degrade to provide a suitable and effective amount of drug. Any suitable and effective amount of drug can be released and will typically depend, e.g., on the specific polymer, drug, and polymer/drug linkage chosen. Typically, up to about 100% of the drug can be released from the polymer/drug. Specifically, up to about 90%, up to 75%, up to 50%, or up to 25% of the drug can be released from the polymer/drug. Factors that typically affect the amount of the drug that is released from the polymer/drug include, e.g., the nature and amount of polymer, the nature and amount of drug, the nature of the polymer/drug linkage, and the nature and amount of additional substances present in the formulation.
The polymer/drug linkage can degrade over a period of time to provide the suitable and effective amount of drug. Any suitable and effective period of time can be chosen. Typically, the suitable and effective amount of drug can be released in about twenty-four hours, in about seven days, in about thirty days, in about ninety days, or in about one hundred and twenty days. Factors that typically affect the length of time in which the drug is released from the polymer/drug include, e.g., the nature and amount of polymer, the nature and amount of drug, the nature of the polymer/drug linkage, and the nature and amount of additional substances present in the formulation.
Polymer/Linker/Drug Linkage
In addition to being directly linked to the residue of a compound of formula (VII) or (XI), the residue of a drug can also be linked to the residue of a compound of formula (VII) or (XI) by a suitable linker. The structure of the linker is not crucial, provided the resulting compound of the invention has an effective therapeutic index as a drug.
Suitable linkers include linkers that separate the residue of a compound of formula (VII) or (XI) and the residue of a drug by about 5 angstroms to about 200 angstroms, inclusive, in length. Other suitable linkers include linkers that separate the residue of a compound of formula (VII) or (XI) and the residue of a drug by about 5 angstroms to about 100 angstroms, inclusive, in length, as well as linkers that separate the residue of a compound of formula (VII) or (XI) and the residue of a drug by about 5 angstroms to about 50 angstroms, or by about 5 angstroms to about 25 angstroms, inclusive, in length.
The linker can be linked to any synthetically feasible position on the residue of a compound of formula (VII) or (XI). Based on the linkage that is desired, one skilled in the art can select suitably functionalized starting materials that can be derived from a compound of formula (VII) or (XI) and a drug using procedures that are known in the art.
The linker can conveniently be linked to the residue of a compound of formula (VII) or (XI) or to the residue of a drug through an amide (e.g., —N(R)C(═O)— or —C(═O)N(R)—), ester (e.g., —OC(═)— or —C(═O)O—), ether (e.g., —O—), ketone (e.g., —C(═O)—) thioether (e.g., —S—), sulfinyl (e.g., —S(O)—), sulfonyl (e.g., —S(O) 2 —), disulfide (e.g., —S—S—), amino (e.g., —N(R)—) or a direct (e.g., C—C) linkage, wherein each R is independently H or (C 1 -C 6 )alkyl. The linkage can be formed from suitably functionalized starting materials using synthetic procedures that are known in the art. Based on the linkage that is desired, one skilled in the art can select suitably functional staring materials that can be derived from a residue of a compound of formula (VII) or (XI), a residue of a drug, and from a given linker using procedures that are known in the art.
Specifically, the linker can be a divalent radical of the formula W-A-Q wherein A is (C 1 -C 24 )alkyl, (C 2 -C 24 )alkenyl, (C 2 -C 24 )alkynyl, (C 3 -C 8 )cycloalkyl, or (C 6 -C 10 )aryl, wherein W and Q are each independently —N(R)C(═O)—, —C(═O)N(R)—, —OC(═O)—, —C(═O)O—, —O—, —S—, —S(O)—, —S(O) 2 —, —S—S—, —N(R)—, —C(═O)—, or a direct bond (i.e., W and/or Q is absent); wherein each R is independently H or (C 1 -C 6 )alkyl.
Specifically, the linker can be a divalent radical of the formula W—(CH 2 ) n -Q wherein, n is between about 1 and about 20, between about 1 and about 15, between about 2 and about 10, between about 2 and about 6, or between about 4 and about 6; wherein W and Q are each independently —N(R)C(═O), —C(═O)N(R)—, —OC(═O)—, —C(═O)O—, —O—, —S—, —S(O)—, —S(O) 2 —, —S—S—, —C(═O)—, —N(R)—, or a direct bond (i.e., W and/or Q is absent); wherein each R is independently H or (C 1 -C 6 )alkyl.
Specifically, W and Q can each independently be —N(R)C(═O)—, —C(═O)N(R)—, —OC(═O)—, —N(R)—, —(C)O—, —O—, or a direct bond (i.e., W and/or Q is absent).
Specifically, the linker can be a divalent radical formed from a saccharide.
Specifically, the linker can be a divalent radical formed from a cyclodextrin.
Specifically, the linker can be a divalent radical, i.e., 1,ω-divalent radicals formed from a peptide or an amino acid. The peptide can comprise 2 to about 25 amino acids, 2 to about 15 amino acids, or 2 to about 12 amino acids.
Specifically, the peptide can be poly-L-lysine (i.e., [—NHCH[(CH 2 ) 4 NH 2 ]CO—] m -Q, wherein Q is H, (C 1 -C 14 )alkyl, or a suitable carboxy protecting group; and wherein m is about 2 to about 25. Specifically, the poly-L-lysine can contain about 5 to about 15 residues (i.e., m is between about 5 and about 15). More specifically, the poly-L-lysine can contain about 8 to about 11 residues (i.e., m is between about 8 and about 11).
Specifically, the peptide can be poly-L-glutamic acid, poly-L-aspartic acid, poly-L-histidine, poly-L-ornithine, poly-L-serine, poly-L-threonine, poly-L-tyrosine, poly-L-leucine, poly-L-lysine-L-phenylalanine, poly-L-argine, or poly-L-lysine-L-tyrosine.
Specifically, the linker can be prepared from 1,6-diaminohexane H 2 N(CH 2 ) 6 NH 2 , 1,5-diaminopentane H 2 N(CH 2 ) 5 NH 2 , 1,4-aminobutane H 2 N(CH 2 ) 4 NH 2 , or 1,3-diaminopropane H 2 N(CH 2 ) 3 NH 2 .
One or more drugs can be linked to the polymer through a linker. Specifically, the residue of each of the drugs can each be linked to the residue of the polymer through a linker. Any suitable number of drugs (i.e., residues thereof) can be linked to the polymer (i.e., residue thereof) through a linker. The number of drugs that can be linked to the polymer, through a linker, can typically depend upon the molecular weight of the polymer. For example, for a compound of formula (VII), wherein n is about 50 to about 150, up to about 450 drugs (i.e., residues thereof) can be linked to the polymer (i.e., residue thereof) through a linker, up to about 300 drugs (i.e., residues thereof can be linked to the polymer (i.e., residue thereof) through a linker, or up to about 150 drugs (i.e., residues thereof) can be linked to the polymer (i.e., residue thereof) through a linker. Likewise, for a compound of formula (XI), wherein n is about 50 to about 150, up to about 450 drugs (i.e., residues thereof) can be linked to the polymer (i.e., residue thereof) through a linker, up to about 300 drugs (i.e., residues thereof) can be linked to the polymer (i.e., residue thereof) through a linker, or up to about 150 drugs (i.e., residues thereof) can be linked to the polymer (i.e., residue thereof) through a linker.
In one embodiment of the present invention, a polymer (i.e., residue thereof) of the present invention can be linked to the linker via the carboxyl group (e.g., COOR 2 ) of the polymer. Specifically, a compound of formula (VII), wherein R 2 is independently hydrogen, or (C 6 -C 10 )aryl(C 1 -C 6 )alkyl; a compound of formula (XI), wherein R 2 is independently hydrogen, or (C 6 -C 10 )aryl(C 1 -C 6 )alkyl; or a combination thereof can react with an amino functional group of the linker or a hydroxyl functional group of the linker, to provide a Polymer/Linker having an amide linkage or a Polymer/Linker having a carboxyl ester linkage, respectively. In another embodiment, the carboxyl group can be transformed into an acyl halide or an acyl anhydride.
In one embodiment of the present invention, a drug (i.e., residue thereof) can be linked to the linker via a carboxyl group (e.g., COOR, wherein R is hydrogen, (C 6 -C 10 )aryl(C 1 -C 6 )alkyl or (C 1 -C 6 )alkyl) of the linker. Specifically, an amino functional group of the drug or a hydroxyl functional group of the drug can react with the carboxyl group of the linker, to provide a Linker/Drug having an amide linkage or a Linker/Drug having a carboxylic ester linkage, respectively. In another embodiment, the carboxyl group of the linker can be transformed into an acyl halide or an acyl anhydride.
The polymer/linker/drug linkage can degrade to provide a suitable and effective amount of drug. Any suitable and effective amount of drug can be released and will typically depend, e.g., on the specific polymer, drug, linker, and polymer/linker/drug linkage chosen. Typically, up to about 100% of the drug can be released from the polymer/linker/drug. Specifically, up to about 90%, up to 75%, up to 50%, or up to 25% of the drug can be released from the polymer/linker/drug. Factors that typically affect the amount of the drug that is released from the polymer/linker/drug include, e.g., the nature and amount ofpolymer, the nature and amount of drug, the nature and amount of linker, the nature of the polymer/linker/drug linkage, and the nature and amount of additional substances present in the formulation.
The polymer/linker/drug linkage can degrade over a period of time to provide the suitable and effective amount of drug. Any suitable and effective period of time can be chosen. Typically, the suitable and effective amount of drug can be released in about twenty-four hours, in about seven days, in about thirty days, in about ninety days, or in about one hundred and twenty days. Factors that typically affect the length of time in which the drug is released from the polymer/linker/drug include, e.g., the nature and amount of polymer, the nature and amount of drug, the nature of the linker, the nature of the polymer/linker/drug linkage, and the nature and amount of additional substances present in the formulation.
Polymer Intermixed with Drug
In addition to being linked to one or more drugs, either directly or through a linker, a polymer of the present invention can be physically intermixed with one or more drugs to provide a formulation.
As used herein, “intermixed” refers to a polymer of the present invention physically mixed with a drug or a polymer of the present invention physically in contact with a drug.
As used herein, a “formulation” refers to a polymer of the present invention intermixed with one or more drugs. The formulation includes a polymer of the present invention having one or more drugs present on the surface of the polymer, partially embedded in the polymer, or completely embedded in the polymer. Additionally, the formulation includes a polymer of the present invention and a drug forming a homogeneous composition (i.e., a homogeneous formulation).
Any suitable amount of polymer and drug can be employed to provide the formulation. The polymer can be present in about 0.1 wt. % to about 99.9 wt. % of the formulation. Typically, the polymer can be present above about 25 wt. % of the formulation; above about 50 wt. % of the formulation; above about 75 wt. % of the formulation; or above about 90 wt. % of the formulation. Likewise, the drug can be present in about 0.1 wt. % to about 99.9.wt. % of the formulation. Typically, the drug can be present above about 5 wt. % of the formulation; above about 10 wt. % of the formulation; above about 15 wt. % of the formulation; or above about 20 wt. % of the formulation.
The polymer/drug, polymer/linker/drug, formulation, or combination thereof can be applied, as a polymeric film, onto the surface of a medical device (e.g., stent). The surface of the medical device can be coated with the polymeric film. The polymeric film can have any suitable thickness on the medical device. For example, the thickness of the polymeric film on the medical device can be about 1 to about 50 microns thick or about 5 to about 20 microns thick. The polymeric film can effectively serve as a drug eluting polymeric coating. This drug eluting polymeric coating can be created by any suitable coating process, e.g., dip coating, vacuum depositing, or spray coating the polymeric film, on the medical device. Additionally, the drug eluting polymer coating system can be applied onto the surface of a stent, a vascular delivery catheter, a delivery balloon, a separate stent cover sheet configuration, or a stent drug delivery sleeves type of local drug delivery systems.
The drug eluting polymer coated stents can be used in conjunction with, e.g., hydrogel-based drug delivery systems.
In addition the above described polymer coated stent, various drugs mixed with hydrogels (see, U.S. Pat. No. 5,610,241) with different elution rate can be applied on the top of the polymer coated stent surface as a sandwich type of configuration to deliver anti restenotic agents to the blood vessels and prevent or reduce in-stent restenosis.
Any suitable size of polymer and drug can be employed to provide the formulation. For example, the polymer can have a size of less than about 1×10 −4 meters, less than about 1×10 −5 meters, less than about 1×10 −6 meters, less than about 1×10 −7 meters, less than about 1×10 −8 meters, or less than about 1×10 −9 meters.
The formulation can degrade to provide a suitable and effective amount of drug. Any suitable and effective amount of drug can be released and will typically depend, e.g., on the specific formulation chosen. Typically, up to about 100% of the drug can be released from the formulation Specifically, up to about 90%, up to 75%, up to 50%, or up to 25% of the drug can be released from the formulation. Factors that typically affect the amount of the drug that is released from the formulation include, e.g., the nature and amount of polymer, the nature and amount of drug, and the nature and amount of additional substances present in the formulation.
The formulation can degrade over a period of time to provide the suitable and effective amount of drug. Any suitable and effective period of time can be chosen Typically, the suitable and effective amount of drug can be released in about twenty-four hours, in about seven days, in about thirty days, in about ninety days, or in about one hundred and twenty days. Factors that typically affect the length of time in which the drug is released from the formulation include, e.g., the nature and amount of polymer, the nature and amount of drug, and the nature and amount of additional substances present in the formulation.
The present invention provides for a formulation that includes a polymer of the present invention physically intermixed with one or more drugs. The polymer that is present in the formulation can also be linked, either directly or through a linker, to one or more (e.g., 1, 2, 3, or 4) drugs. As such, a polymer of the present invention can be intermixed with one or more (e.g., 1, 2, 3, or 4) drugs and can be linked, either directly or through a linker, to one or more (e.g., 1, 2, 3, or 4) drugs.
A polymer of the present invention can include one or more drugs. In one embodiment, a polymer of the present invention can be physically intermixed with one or more drugs. In another embodiment, a polymer of the present invention can be linked to one or more drugs, either directly or through a linker. In another embodiment, a polymer of the present invention can be linked to one or more drugs, either directly or through a linker, and the resulting polymer can be physically intermixed with one or more drugs.
A polymer of the present invention, whether or not present in a formulation as described herein, whether or not linked to a drug as described herein, and whether or not intermixed with a drug as described herein, can be used in medical therapy or medical diagnosis. For sale, the polymer can be used in the manufacture of a medical device. Suitable medical devices include, e.g., artificial joints, artificial bones, cardiovascular medical devices, stents, shunts, medical devices useful in angioplastic therapy, artificial heart valves, artificial by-passes, sutures, artificial arteries, a vascular delivery catheters, a delivery balloons, separate stent cover sheet configurations, and stent drug delivery sleeve types of local drug delivery systems.
All publications, patents, and patent documents are incorporated by reference herein, as though individually incorporated by reference. The invention has been described with reference to various specific and preferred embodiments and techniques. However, it should be understood that many variations and modifications may be made while remaining within the spirit and scope of the invention.
The present invention will now be illustrated by the following non-limiting examples.
EXAMPLES
Preparation of copoly(ester amide)s (coPEAs) and copoly(ester urethane)s (coPEURs) (General Procedure)
Dry triethylamine (Net 3 ) (30.8 mL, 0.22 mole) was added to a mixture of predetermined quantities of the di-p-toluenesulfonic acid salt of bis-(L-α-amino acid)α,ω-alkylene diester (III) and the di-p-toluenesulfonic acid salt of L-lysine benzyl ester (IV) (total amount of (III)+(IV)=0.1 mole), and active diester (V) or active bis-carbonate (IV) (0.1 mole) in dry N,N-diethylacetamide (DMA) (52.5 mL) (total volume of DMA and NEt 3 is 83.3 mL, concentration 1.2 mol/L by (III)+(IV) or by (V)) at room temperature. Afterwards, the temperature of the reaction mixture was increased to about 80° C. and stirred for about 16 hours. The viscous reaction solution was cooled to room temperature, diluted with ethanol (150 mL), and poured into cool water. The separated polymer was thoroughly washed with water, dried at about 30° C. under reduced pressure (for final purification of coPEAs and coPEURs see below). Reduced viscosity data (η red ) of the polymers were obtained in m-cresol at a concentration of 0.5 g/dL and t=25° C.
Preparation of Co-PEAs:
Example 1
Preparation of co-poly-{[N,N′-adipoyl-bis-(L-leucine)-1,6-hexylene diester]} 0.75 -{[N,N′-adipoyl-L-lysine benzyl ester] 0.25 } (1) (compound of formula (VII) wherein m=0.75, p=0.25, n=75, R 1 ═(CH 2) 4 , R 2 =Bz, R 3 =isopropyl, and R 4 ═(CH 2 ) 6 ).
Dry triethylamine (30.8 mL, 0.22 mole) was added to the mixture of the di-p-toluenesulfonic acid salt of bis-(L-leucine)-1,6-hexylene diester (III, R 4 ═(CH 2 ) 6 ) (50.168 g, 0.075 mole); the di-p-toluenesulfonic acid salt of L-lysine benzyl ester (IV) (total amount of (III)+(IV)=0.1 mole) (14.518 g, 0.025 mole); and di-p-nitrophenyl adipate (V, R 1 ═(CH 2 ) 4 ) (38.833 g, 0.1 mole) in dry N,N-dimethylacetamide (52.5 mL) (total volume of DMA and NEt 3 is 83.3 mL, concentration 1.2 mol/L by (III)+(IV) or by (V)) at room temperature. Afterwards, the temperature of the reaction mixture was increased to about 80° C. and stirred for about 16 hours. The viscous reaction solution was cooled to room temperature, diluted with ethanol (150 mL), and poured into water. The separated polymer was thoroughly washed with water, dried at about 30° C. under reduced pressure. After final purification up to negative test on p-nitrophenol and p-toluenesulfonic acid (see below), yield is 90%, η red =1.30 dL/g. Mw=32,100, Mn=27,000, Mw/Mn=1.19 (GPC in THF).
Example 2
Preparation of co-poly-{[N,N′-sebacoyl-bis-(L-leucine)-1,6-hexylene diester]} 0.75 -{[N,N′-sebacoyl-L-lysine benzyl ester] 0.25 } (2) (compound of formula (VII) wherein m=0.75, p=0.25, n=65, R 1 ═(CH 2 ) 8 , R 2 =Bz, R 3 =iso-propyl, and R 4 ═(CH 2 ) 6 ).
Dry triethylamine (30.8 mL, 0.22 mole) was added to the mixture of di-p-toluenesulfonic acid salt of bis-(L-leucine)-1,6hexylene diester (III, R 4 ═(CH 2 ) 6 ) (50.168 g (0.075 mole); the di-p-toluenesulfonic acid salt of L-lysine benzyl ester (IV) (14.518 g, 0.025 mole) (total amount of (III)+(V)=0.1 mole), and di-p-nitrophenyl sebacinate (V, R 1 ═(CH 2 ) 8 ) (44.444 g, 0.1 mole) in dry N,N-dimethylacetamide (DMA) (52.5 mL) (total volume of DMA and NEt 3 is 83.3 mL, concentration 1.2 mol/L by (III)+(IV) or by (V)) at room temperature. Afterwards, the temperature of the reaction mixture was increased to about 80° C. and stirred for about 16 hours. The viscous reaction solution was cooled to room temperature, diluted with ethanol (150 mL), and poured into water. The separated polymer was thoroughly washed with water, dried at about 30° C. under reduced pressure. After final purification up to negative test on p-nitrophenol and p-toluenesulfonic acid (see below), yield is 91%, η red =1.40 dL/g. Mw=31.300, Mn=21.000, Mw/Mn=1.49 (GPC in TEF). Biodegradation (weight loss in %) at 37° C. after 120 h in phosphate buffer (pH 7.4): ˜0% weight loss in pure buffer, 1-2% in the buffer with α-chymotrypsin (4 mg/10 mL of buffer), 1-2% in the buffer with lipase (4 mg/10 mL of buffer).
Example 3
Preparation of co-poly-{[N,N′-adipoyl-bis-(L-leucine)-1,6-hexylene diester)} 0.50 -[N,N′-adipoyl-bisphenylalamine)-1,6-hexylene diester] 0.25 -{[N,N′-adipoyl-L-lysine benzyl ester] 0.25 } (3) (compound of formula (VII) wherein m=0.50, p=0.50, R 1 ═(CH 2 ) 4 , R 1 =Bz, R 3 =iso-propyl and Bz, and R 4 ═(CH 2 ) 6 and Bz).
Dry triethylamine (30.8 mL, 0.22 mole) was added to the mixture of the di-p-toluenesulfonic acid salt of bis-(L-leucine)-1,6-hexylene diester (III, R 4 ═(CH 2 ) 6 ) (34.446 g, 0.050 mole), the di-p-toluenesulfonic acid salt of bis-(L-phenylalanine)1,6-hexylene diester (III, R 4 ═CH 2 Ph) (18.924 g, 0:025 mole), the di-p-toluenesulfonic acid salt of L-lysine benzyl ester (IV) (14.5180 g, 0.025 mole) (total amount of (III)+(IV)=0.1 mole), and di-p-nitrophenyl adipate (V, R 1 ═(CH 2 ) 4 ) (38.833, 0.1 mole) in dry N,N-dimethylacetamide (DMA) (52.5 mL of) (total volume of DMA and NEt 3 is 83.3 mL, concentration 1.2 mol/L by (III)+(IV) or by (V)) at room temperature. Afterwards, the temperature of the reaction mixture was increased to about 80° C. and stirred for about 16 hours. The viscous reaction solution was cooled to room temperature, diluted with ethanol (150 mL), and poured into water. The separated polymer was thoroughly washed with water, dried at about 30° C. under reduced pressure. After final purification up to negative test on p-nitrophenol and p-toluenesulfonic acid (see below), yield is 94%, η red =1.40 dL/g. Biodegradation (weight loss in %) at 37° C. after 120 h in phosphate buffer (pH 7.4): ˜0% inpure buffer, 10% in the buffer with α-chymotrpsin (4 mg/10 mL of buffer), and 35% in the buffer with lipase (4 mg/10 mL of buffer).
Example 4
Preparation of co-poly-{[N,N′-sebacoyl-bis-(L-leucine)-1,6-hexylene diester]} 0.50 -[N,N′-sebacoyl(bis-L-phenylalamine)-1,6-hexylene diester]-{[N,N′-sebacoyl-L-lysine benzyl ester] 0.25 } (4) (compound of formula (VII) wherein m 1 =0.50, m 2 =0.25, p=0.25, R 1 ═(CH 2 ) 8 , R 2 =Bz, R 3 =iso-propyl, and R 4 ═(CH 2 ) 6 ).
Dry triethylamine (30.8 mL, 0.22 mole) was added to the mixture of the of di-p-toluenesulfonic acid salt of bis(L-leucine)-1,6-hexylene diester (III, R 4 ═(CH 2 ) 6 ) (34.446 g, 0.050 mole), the di-p-toluenesulfonic acid salt of bis-(L-phenylalanine) 1,6 hexylene diester (III, R 4 ═CR 2 Ph) (18.924 g, 0.025 mole), the di-p-toluenesulfonic acid salt of L-lysine benzyl ester (IV) (14.518 g, 0.025 mole) (total amount of (III)+(IV)=0.1 mole), and di-p-nitrophenyl sebacinate (V, R 1 ═(CH 2 ) 8 ) (44.444 g, 0.1 mole) in dry N,N-dimethylacetamide (DMA) (52.5 mL) (total volume of DMA and NEt 3 is 83.3 mL, concentration 1.2 mol/L by (III)+(IV) or by (V)) at room temperature. Afterwards, the temperature of the reaction mixture was increased to about 80° C. and stirred for about 16 hours. The viscous reaction solution was cooled to room temperate, diluted with ethanol (150 mL), and poured into water. The separated polymer was thoroughly washed with water, dried at about 30° C. under reduced pressure. After final purification up to negative test on p-nitrophenol and p-toluenesulfonic acid (see below) yield is 95%, η red =0.77 dL/g. Tg=20.6° C. (DSC).
Example 5
Preparation of co-poly-{[N,N′-adipoyl-bis-(L-leucine)-1,6-hexylene diester]} 0.50 -{[N,N′-adipoyl-L-lysine benzyl ester] 0.50 } (5) (compound of formula (VII) wherein m=0.50, p=0.50, R═(CH 2 ) 4 , R 2 =Bz, R 3 =iso-propyl, and R 4 ═(CH 2 ) 6 ).
Dry triethylamine (30.8 mL, 0.22 mole) was added to the mixture of the di-p-toluenesulfonic acid salt of bis-(L-leucine) 1,6 -hexylene diester (III, R 4 ═(CH 2 ) 6 ) (34.446 g, 0.050 mole), the di-p-toluenesulfonic acid salt of L-lysine benzyl ester (IV) (29.036 g, 0.050 mole) (total amount of (III)+(IV) 0.1 mole), and di-p-nitrophenyl adipate (V, R 1 ═(CH 2 ) 4 ) (38.833 g, 0.1 mole) in dry N,N-dimethylacetamide (DMA) (52.5 mL) (total volume of DMA and NEt 3 is 83.3 mL, concentration 1.2 mol/L by (III)+(IV) or by (V)) at room temperature. Afterwards, the temperature of the reaction mixture was increased to about 80° C. and stirred for about 16 hours. The viscous reaction solution was cooled to room temperature, diluted with ethanol (150 mL), and poured into water. The separated polymer was thoroughly washed with water, dried at about 30° C. under reduced pressure. After final purification up to negative test on p-nitrophenol and p-toluenesulfonic acid (see below) yield is 93%, η red =1.25 dL/g.
Example 6
Preparation of co-poly-{[N,N′-sebacoyl-bis-(L-leucine)-1,6-hexylene diester]} 0.50 -{[N,N′-sebacoyl-L-lysine benzyl ester] 0.50 } (6) (compound of formula (VII) wherein m=0.50, p=0.50, R 1 ═(CH 2 ) 8 , R 2 =Bz, R 3 =iso-propyl, and R 4 ═(CH 2 ) 6 ).
Dry triethylamine (30.8 mL, 0.22 mole) was added to the mixture of the di-p-toluenesulfonic acid salt of bis-(L-leucine)-1,6-hexylene diester (III, R 4 ═(CH 2 ) 6 ) (34.446 g, 0.050 mole), the di-p-toluenesulfonic acid salt of L-lysine benzyl ester (IV) (29.036 g, 0.050 mole) (total amount of (III)+(IV)=0.1 mole), and di-p-nitrophenyl sebacinate (V, R 1 ═(CH 2 ) 8 (44.444 g, 0.1 mole) in dry N,N-dimethylacetamide (DMA) (52.5 mL) (total volume of DMA and NEt 3 is 83.3 mL, concentration 1.2 mol/L by (III)+(IV) or by (V)) at room temperature. Afterwards, the temperate of the reaction mixture was increased to about 80° C. and stirred for about 16 hours. The viscous reaction solution was cooled to room temperature, diluted with ethanol (150 mL), and poured into water. The separated polymer was thoroughly washed with water, dried at about 30° C. under reduced pressure. After final purification up to negative test on p-nitrophenol and p-toluenesulfonic acid (see below) yield is 95%, η red =1.31 dL/g.
Example 7
Preparation of co-poly-{[N,N′-adipoyl-bis-(L-leucine)-1,8-octylene diester]} 0.90 -{[N,N′-adipoyl-L-lysine benzyl ester] 0.10 } (7) (compound of formula (VII) wherein m=0.90, p=0.10, R 1 ═(CH 2 ) 4 , R 2 =Bz, R 3 =iso-propyl, and R 4 ═(CH 2 ) 8 ).
Dry triethylamine (30.8 mL, 0.22 mole) was added to the mixture of the di-p-toluenesulfonic acid salt of bis-L-leucine)-1,8-octylene diester (III, R 4 ═(CH 2 ) 8 ) (64.526 g, 0.090 mole), the di-p-toluenesulfonic acid salt of L-lysine benzyl ester (IV) (5.807 g, 0.010 mole) (total amount of (III)+(IV)=0.1 mole), and di-p-nitrophenyl adipate (V, R 1 ═(CH 2 ) 4 ) (38.833, 0.1 mole) in dry N,N-dimethylacetamide (DMA) (52.5 mL) (total volume of DMA and NEt 3 is 83.3 mL, concentration 1.2 mol/L by (III)+(IV) or by (V)) at room temperature. Afterwards, the temperature of the reaction mixture was increased to about 80° C. and stirred for about 16 hours. The viscous reaction solution was cooled to room temperature, diluted with ethanol (150 mL), and poured into water. The separated polymer was thoroughly washed with water, dried at about 30° C. under reduced pressure. After final purification up to negative test on p-nitrophenol and p-toluenesulfonic acid (see below) yield is 94%, η red =1.21 dL/g.
Example 8
Preparation of co-poly-{[N,N′-sebacoyl-bis-(L-leucine)-1,4-butylene diester]}) 0.90 -({[N,N′-sebacoyl-L-lysine benzyl ester] 0.10 } (8) (compound of formula (VII) wherein m=0.90, p=0.10, R 1 ═(CH 2 ) 8 , R 2 =Bz, R 3 =iso-propyl, and R 4 ═(CH 2 ) 4 ).
Dry triethylamine (30.8 mL, 0.22 mole) was added to the mixture of the di-p-toluenesulfonic acid salt of bis-(L-leucine)-1,4-butylene diester (III, R 4 ═(CH 2 ) 4 ) (59.477 g, 0.090 mole), the di-p-toluenesulfonic acid salt of L-lysine benzyl ester (IV) 5.807 g, 0.010 mole) (total amount of (III)+(IV)=0.1 mole), and di-p-nitrophenyl sebacinate (V, R 1 ═(CH 2 ) 8 ) (44.444 g 0.1 mole) in N,N-dimethylacetamide (DMA) (52.5 mL of) (total volume of DMA and NEt 3 is 83.3 mL, concentration 1.2 mol/L by (III)+(IV) or by (V)) at room temperature. Afterwards the temperature of the reaction mixture was increased to about 80° C. and stirred for about 16 hours. The viscous reaction solution was cooled to room temperature, diluted with ethanol (150 mL), and poured into water. The separated polymer was thoroughly washed with water, dried at 30° C. under reduced pressure. After final purification up to negative test on p-nitrophenol and p-toluenesulfonic acid (see below) yield is 95%, η red =1.28 dL/g.
Example 9
Preparation of co-poly-{[N,N′-sebacoyl-bis-(L-leucine)-1,6-hexylene diester]} 0.90 -{[N,N′-sebacoyl-L-lysine benzyl ester] 0.10 } (9) (compound of formula (VII) wherein m=0.90, p=0.10, R 1 ═(CH 2 ) 8 , R 2 =Bz, R 3 =iso-propyl, and R 4 ═(CH 2 ) 6 ).
Dry triethylamine (30.8 mL, 0.22 mole) was added to the mixture of the di-p-toluenesulfonic acid salt of bis-(L-leucine)-1,6-hexylene diester (III, R 4 ═(CH 2 ) 6 ) (62.002 g, 0.090 mole), the di-p-toluenesulfonic acid salt of L-lysine benzyl ester (IV) (5.807 g, 0.010 mole) (total amount of (III)+(IV)=0.1 mole), and di-p-nitrophenyl sebacinate (V, R 1 ═(CH 2 ) 8 ) (44.444 g, 0.1 mole) in dry N,N-dimethylacetamide (DMA) (52.5 mL) (total volume of DMA and NEt 3 is 83.3 mL, concentration 1.2 mol/L by (III)+(IV) or by (V)) at room temperature. Afterwards, the temperature of the reaction mixture was increased to about 80° C. and stirred for about 16 hours. The viscous reaction solution was cooled to room temperature, diluted with ethanol (150 mL), and poured into water. The separated polymer was thoroughly washed with water, dried at about 30° C. under reduced pressure. After final purification up to negative test on p-nitrophenol and p-toluenesulfonic acid (see below) yield is 96%, η red =1.41 dL/g. Biodegradation (weight loss in %) at 37° C. after 120 h in phosphate buffer (pH 7.4): ˜0% in pure buffer, 12% in the buffer with α-chymotrypsin (4 mg/10 mL of buffer), and 38% in the buffer wifth lipase (4 mg/10 mL of buffer).
Example 10
Preparation of co-poly-{[N,N′-sebacoyl-bis(L-leucine)-1,8-octylene diester]} 0.90 -{[N,N′-sebacoyl-L-lysine benzyl ester] 0.10 } (10) (compound of formula (VII) herein m=0.90, p=0.10, R 1 ═(CH 2 ) 8 , R 2 =Bz, R 3 =iso-propyl, and R 4 ═(CH 2 ) 8 ).
Dry triethylamine (30.8 mL, 0.22 mole) was added to the mixture of the di-p-toluenesulfonic acid salt of bis-(L-leucine)-1,8-octylene diester (III, R 4 ═(CH 2 ) 8 ) (64.526 g, 0.090 mole), the di-p-toluenesulfonic acid salt of L-lysine benzyl ester (IV) (5.807 g, 0.010 mole) (total amount of (III)+(IV)=0.1 mole), and di-p-nitrophenyl sebacinate (V, R 1 ═(CH 2 ) 8 ) (44.444 g, 0.1 mole) in dry N,N-dimethylacetamide (DMA) (52.5 mL) (total volume of DMA and NEt 3 is 83.3 mL, concentration 1.2 mol/L by (III)+(V) or by (V)) at room temperature. Afterwards, the temperature of the reaction mixture was increased to about 80° C. and stirred for about 16 hours. The viscous reaction solution was cooled to room temperature, diluted with ethanol (150 mL), and poured into water. The separated polymer was thoroughly washed with water, dried at about 30° C. under reduced pressure. After final purification up to negative test on p-nitrophenol and p-toluenesulfonic acid (see below) yield is 97%, η red =1.50 dL/g. Tg 27.5° C. (DSC).
Example 11
Preparation of co-poly-{[N,N′-sebacoyl-bis-(L-leucine)-1,12-dodecylene diester]} 0.90 -{[N,N′-sebacoyl-L-lysine benzyl ester] 0.10 } (11) (compound of formula (VII) wherein m=0.90, p=0.10, R 1 ═(CH 2 ) 8 , R 2 =Bz, R 4 =iso-propyl, and R 4 ═(CH 2 ) 12 ).
Dry triethylamine (30.8 mL, 0.22 mole) was added to the mixture of the di-p-toluenesulfonic acid salt of bis-(L-leucine)-1,12-dodecylene diester (III, R 4 ═(CH 2 ) 12 ) (69.576 g, 0.090 mole), the di-p-toluenesulfonic acid salt of lysine benzyl ester (V) (5.807 g, 0.010 mole) (total amount of (III)+(IV)=0.1 mole), and di-p-nitrophenyl sebacinate (V, R 1 ═(CH 2 ) 8 ) (44.444 g, 0.1 mole) in dry N,N-dimethylacetamide (DMA) (52.5 mL) (total volume of DMA and NEt 3 is 83.3 mL, concentration 1.2 mol/L by (III)+(IV) or by (V)) at room temperature. Afterwards, the temperature of the reaction mixture was increased to about 80° C. and stirred for about 16 hours. The viscous reaction solution was cooled to room temperature, diluted with ethanol (150 mL), and poured into water. The separated polymer was thoroughly washed with water, dried at about 30° C. under reduced pressure. After final purification, yield is 96% up to negative test on p-nitrophenol and p-toluenesulfonic acid (see below), η red =0.68 dL/g.
Example 12
Preparation of co-poly-{[N,N′-dodecyldicarboxyloyl-bis-(L-leucine)-1,6-hexylene diester]} 0.90 -{[N,N′-dodecyldicarboxyloyl-L-lysine benzyl ester] 0.10 } (12) (compound of formula (VII) wherein m=0.90, p=0.10, R 1 ═(CH 2 ) 12 , R 2 =Bz, R 3 =iso-propyl, and R 4 ═(CH 2 ) 6 ).
Dry triethylamine (30.8 mL, 0.22 mole) was added to the mixture of the di-p-toluenesulfonic acid salt of bis-(L-leucine)-1,6hexylene diester (III, R 4 ═(CH 2 ) 6 ) (62.002 g, 0.090 mole), the di-p-toluenesulfonic acid salt of L-lysine benzyl ester (IV) (5.807 g, 0.010 mole) (total amount of (III)+(IV)=0.1 mole), and di-p-nitrophenyl dodecyldicarboxylate (V, R 1 ═(CH 2 ) 12 ) (50.055 g, 0.1 mole) in dry N,N-dimethylacetamide (DMA) (52.5 mL) (total volume of DMA and NEt 3 in 83.3 mL, concentration 1.2 mol/L by (III)+(IV) or by (V)) at room temperature. Afterwards the temperature of the reaction mixture was increased to about 80° C. and stirred for about 16 hours. The viscous reaction solution was cooled to room temperature, diluted with ethanol (150 mL), and poured into water. The separated polymer was thoroughly washed with water, dried at 30° C. under reduced pressure. After final purification yield is 96% up to negative test on p-nitrophenol and p-toluenesulfonic acid (see below), η red =1.18 dL/g.
Preparation of Co-PEURs:
Example 13
Preparation of co-poly-{[N,N′-trimethylenedioxydicarbonyl-bis-(L-leucine)-1,4-butylene diester]} 0.75 -{[N,N′-trimethylenedioxydicarbonyl-L-lysine benzyl ester] 0.25 } (13) (compound of formula (XI) wherein m=0.75, p=0.25, R 2 =Bz R 3 =iso-propyl, R 4 ═(CH 2 ) 4 ), and R 6 ═(CH 2 ) 3 .
Dry triethylamine (30.8 mL, 0.22 mole) was added to the mixture of the di-p-toluenesulfonic acid salt of bis(L-leucine)-1,4butylene diester (III, R 4 ═(CH 2 ) 4 ) (49.565 g, 0.075 mole), the di-p-toluenesulfonic acid salt of L-lysine benzyl ester (IV) (14.518 g, 0.025 mole) (total amount of (III)+(IV)=0.1 mole), and active biscarbonate (X) (R 6 ═(CH 2 ) 3 ) (40.624 g, 0.1 mole) in dry N,N-dimethylacetamide (DMA) (52.5 mL) (total volume of DMA and NEt 3 in 83.3 mL, concentration 1.2 mol/L by (III)+(IV) or by (X)) at room temperature. Afterwards, the temperature of the reaction mixture was increased to about 80° C. and stirred for about 16 hours. The viscous reaction solution was cooled to room temperature, and poured into water. The separated polymer was thoroughly washed with water, dried at 30° C. under reduced pressure. After final purification up to negative test on p-nitrophenol and p-toluenesulfonic acid (see below) yield is 63%, η red =0.32 dL/g.
Example 14
Preparation of co-poly-{[N,N′-(3-oxapentylene-1,5-ioxydicarbonyl)-bis-(L-leucine)-1,4-butylene diester]} 0.75 -{[N,N′-3-oxapentylene-1,5-dioxydicarbonyl)-L-lysine benzyl ester] 0.25 } (14) (compound of formula (XI) wherein m=0.75, p=0.25, R 2 =Bz, R 3 =iso-propyl, R 4 ═(CH 2 ) 4 ), and R 6 ═(CH 2 ) 2 —O—(CH 2 ) 2 ).
Dry triethylamine (30.8 mL, 0.22 mole) was added to the mixture of the di-p-toluenesulfonic acid salt of bis-(L-leucine)-1,4-butylene diester (III, R 4 ═(CH 2 ) 4 ) (49.565 g 0.075 mole), the di-p-toluenesulfonic acid salt of L-lysine benzyl ester (IV) (14.518 g, 0.025 mole) (total amount of (III)+(IV)=0.1 mole), and active bis-carbonate (X) (R 6 ═(CH 2 ) 2 —O—(CH 2 ) 2 ) (43.633 g, 0.1 mole) in dry N,N-dimethylacetamide (DMA) (52.5 mL) (total volume of DMA and NEt 3 is 83.3 mL, concentration 1.2 mol/L by (III)+(IV) or by (X)) at room temperature. Afterwards, the temperature of the reaction mixture was increased to about 80° C. and bred for about 16 hours. The viscous reaction solution was cooled to room temperature, and poured into water. The separated polymer was thoroughly washed with water, dried at about 30° C. under reduced pressure. After final purification up to negative test on p-nitrophenol and p-toluenesulfonic acid (see below) yield is 78%, η red =0.58 dL/g. Biodegradation (weight loss in %) at 37° C. after 240 h in phosphate buffer (pH 7.4): 4.7% in pure buffer, 2.2% in the buffer with α-chymotypsin (4 mg/10 mL of buffer), 4.4% in the buffer with lipase (4 mg/10 mL of buffer). Films with d=4 cm and m=500±50 mg on Teflon backing.
Example 15
Preparation of co-poly-{[N,N′-trimethylenedioxydicarbonyl-bis-(L-leucine)-1,6-hexylene diester]} 0.75 -{[N,N′-trimethylenedioxydicarbonyl-L-lysine benzyl ester] 0.25 } (15) (compound of formula (XI) wherein m=0.75, p=0.25, n=112, R 2 =Bz, R 3 =iso-propyl, R 4 ═(CH 2 ) 6 ), and R 6 ═(CH 2 ) 3 .
Dry triethylamine (30.8 mL, 0.22 mole) was added to the mixture of the di-p-toluenesulfonic acid salt of bis-(L-leucine)-1,6-hexylene diester (III, R 4 ═(CH 2 ) 6 ) (51.668 g, 0.075 mole), the di-p-toluenesulfonic acid salt of L-lysine benzyl ester (IV) (14.518 g, 0.025 mole) (total amount of (III)+(IV)=0.1 mole), and active bis-carbonate (X) (R 6 ═(CH 2 ) 3 ) (40.624 g, 0.1 mole) in dry N,N-dimethylacetamide (DMA) (52.5 mL) (total volume of DMA and NEt 3 is 83.3 mL, concentration 1.2 mol/L by (III)+(IV) or by (X)) at room temperature. Afterwards, the temperature of the reaction mixture was increased to about 80° C. and stirred for about 16 hours. The viscous reaction solution was cooled to room temperature, and poured into water. The separated polymer was thoroughly washed with water, dried at about 30° C. under reduced pressure. After final purification up to negative test on p-nitrophenol and p-toluenesulfonic acid (see below) yield is 60%, η red =0.53 dL/g. Mw=50,000, Mn=29,900, M w /M n =1.68 (GPC). Biodegradation (weight loss in %) at 37° C. after 180 h in phosphate buffer (pH 7.4): 5.0% in pure buffer, 7.3% in the buffer with α-chymotwypsin (4 mg/10 mL of buffer), and 8.2% in the buffer with lipase (4 mg/10 mL of buffer). Films with d=4 cm and m=500±50 mg on Teflon backing.
Example 16
Preparation of co-poly-{[N,N′-(3-oxapentylene-1,5-dioxydicarbonyl)-bis-(L-leucine)-1,6-hexylene diester])} 0.75 -{[N,N′-(3-oxapentylene-1,5-dioxycarbonyl)-L-lysine benzyl ester] 0.25 } (16) (compound of formula (XI) wherein m=0.75, p=0.25, n=130, R 2 =Bz, R 3 =iso-propyl, R 4 ═(CH 2 ) 6 ), and R 6 ═(CH 2 ) 2 —O—(CH 2 ) 2 ).
Dry triethylamine (30.8 ml, 0.22 mole) was added to the mixture of the di-p-toluenesulfonic acid salt of bis-L-leucine)-1,6-hexylene diester (III, R 4 ═(CH 2 ) 6 ) (51.668 g, 0.075 mole), the di-p-toluenesulfonic acid salt of L-lysine benzyl ester (IV) (14.518 g, 0.025 mole) (total amount of (III)+(IV)=0,1 mole), and active bis-carbonate (X) (R 6 ═(CH 2 ) 2 —O—CH 2 ) 2 ) (43.633 g, 0.1 mole) in dry N,N-dimethylacetamide (DMA) (52.5 mL) (total volume of DMA and NEt 3 is 83.3 mL, concentration 1.2 mol/L by (III)+(IV) or by (X)) at room temperature. Afterwards, the temperature of the reaction mixture was increased to about 80° C. and sized for about 16 hours. The viscous reaction solution was cooled to room temperature, and poured into water. The separated polymer was thoroughly washed with water, dried at about 30° C. under reduced pressure. After final purification up to negative test on p-nitrophenol and p-toluenesulfonic acid (see below) yield is 68% η red =0.72 dL/g. Mw=61,900, Mn=38,500, Mw/Mn=1.61 (GPC). Biodegradation (weight loss in %) at 37° C. after 180 h in phosphate buffer (pH 7.4): 4.0% in pure buffer, 5.6% in thebuffer wil α-chymotrypsin (4 mg/10 mL of buffer), and 8.9% in the buffer with lipase (4 mg/10 mL of buffer). Film with d=4 cm and m=500±50 mg on Teflon backing.
Example 17
Preparation of co-poly-{[N,N′-(3-oxapentylene-1,5-dioxydicarbonyl)-bis-(L-leucine)-1,6-hexylene diester]} 0.90 -{[N,N′-3-oxapentylene-1,5-dioxydicarbonyl)-L-lysine benzyl ester] 0.50 } (17) (compound of formula (XI) wherein m=0.50, p=0.50, n=85, R 2 =Bz, R 3 =iso-propyl, R 4 ═(CH 2 ) 6 ), and R 6 ═(CH 2 ) 2 —O—(CH 2 ) 2 ).
Dry triethylamine (30.8 mL, 0.22 mole) was added to the mixture of di-p-toluenesulfonic acid salt of bis(L-leucine)-1,6-hexylene diester (III, R 4 ═(CH 2 ) 6 ) (34.446 g, 0.050 mole), the di-p-toluenesulfonic acid salt of L-lysine benzyl ester (IV) (29.036 g, 0.050 mole) (total amount of (III)+(IV)=0.1 mole), and active bis-carbonate (X) (R 6 ═(CH 2 ) 2 —O—(CH 2 ) 2 ) (43.633 g, 0.1 mole) in dry N,N-dimethylacetamide (DMA) (52.5 mL) (total volume of DMA and NEt 3 is 83.3 mL, concentration 1.2 mol/L by (III)+(IV) or by (X)) at room temperature. Afterwards, the temperature of the reaction mixture was increased to about 80° C. and stirred for about 16 hours. The viscous reaction solution was cooled to room temperature, and poured into water. The separated polymer was thoroughly washed with water, dried at about 30° C. under reduced pressure. After final purification up to negative test on p-nitrophenol and p-toluenesulfonic acid (see below) yield is 80%, η red =0.45 dL/g. M w =37,900, M n =22,300, Mw/Mn=1.70 (GPC).
Example 18
Preparation of co-poly-{[N,N′-(3-oxapentylene-1,5-dioxydicarbonyl)-bis-(L-leucine)-1,6-hexylene diester]} 0.90 -{[N,N′-(3-oxapentylene-1,5-dioxydicarbonyl)-L-lysine benzyl ester] 0.10 } (18) (compound of formula (XI) wherein m=0.90, p=0.10, n=115, R 2 =Bz, R 3 =iso-propyl, R 4 ═(CH 2 ) 6 ), and R 6 ═(CH 2 ) 2 —O—(CH 2 ) 2 ).
Dry triethylamine (30.8 mL, 0.22 mole) was added to the mixture of the di-p-toluenesulfonic acid salt of bis-(L-leucine)-1,6-hexylene diester (III, R 4 ═(CH 2 ) 6 ) (62.002 g, 0.090 mole), the di-p-toluenesulfonic acid salt of L-lysine benzyl ester (IV) (5.807 g, 0.025 mole) (total amount of (III)+(IV)=0.1 mole), and active bis-carbonate (X) (R 6 ═(CH 2 ) 2 —O—(CH 2 ) 2 ) (43.633 g, 0.1 mole) in dry N,N-dimethylacetamide (DMA) (52.5 mL) (total volume of DMA and NEt 3 is 83.3 mL, concentration 1.2 mol/L by (III)+(IV) or by (X)) at room temperature. Afterwards, the temperature of the reaction mixture was increased to about 80° C. and stirred for about 16 hours. The viscous reaction solution was cooled to room temperature, and poured into water. The separated polymer was thoroughly washed with water, dried at about 30° C. under reduced pressure. After final purification up to negative test on p-nitrophenol and p-toluenesulfonic acid (see below) yield is 70% η red =0.74 dL/g. M w =56,500, M n =33,700, M w /M n =1.68 (GPC).
Example 19
Preparation of co-poly-{[N,N′-trimethylenedioxydicarbonyl-bis-(L-leucine)-1,8-octylene diester]} 0.75 -{[N,N′-trimethylenedioxydicarbonyl-L-lysine benzyl ester] 0.25 } (19) (compound of formula (XI) wherein m=0.75, p=0.25, R 2 =Bz, R 3 =iso-propyl, R 4 ═(CH 2 ) 8 ), and R 6 ═(CH 2 ) 3 .
Dry triethylamine (30.8 mL, 0.22 mole) was added to the mixture of the di-p-toluenesulfonic acid salt of bis-(L-leucine)-1,8-octylene diester (III, R 4 ═(CH 2 ) 8 ) (53.772 g, 0.075 mole), the di-p-toluenesulfonic acid salt of L-lysine benzyl ester (IV) (14.518 g, 0.025 mole) (total amount of (III)+(V)=0.1 mole), and active bis-carbonate (X) (R 6 ═(CH 2 ) 3 ) (40.624 g, 0.1 mole) in dry N,N-dimethylacetamide (DMA) (52.5 mL) (total volume of DMA and NEt 3 is 83.3 mL, concentration 1.2 mol/L by (III)+(IV) or by (X)) at room temperature. Afterwards, the temperature of the reaction mixture was increased to about 80° C. and stirred for about 16 hours. The viscous reaction solution was cooled to room temperature, and poured into water. The separated polymer was thoroughly washed with water, dried at about 30° C. under reduced pressure. After final purification up to negative test on p-nitrophenol and p-toluenesulfonic acid (see below) yield is 84%, η red =0.46 dL/g. Biodegradation (weight loss in %) at 37° C. after 240 h in phosphate buffer (pH 7.4): 0.9% in pure buffer, 2.0% in the buffer with α-chymotrrpsin (4 mg/10 mL of buffer), and 3.7% in the buffer with lipase (4 mg/10 mL of buffer). Films with d=4 cm and m=500±50 mg on Teflon backing.
Example 20
Preparation of co-poly-{[N,N′-(3-oxapentylene-1,5-dioxydicarbonyl)-bis-(L-leucine)-1,8-octylene diester]} 0.75 -{[N,N′-(3-oxapentylene-1,5-dioxydicarbonyl)-L-lysine benzyl ester] 0.25 } (20) (compound of formula (XI) wherein m=0.75, p=0.25, R 2 =Bz, R 3 =iso-propyl, R 4 =(CH 2 ) 8 ), and R 6 ═(CH 2 )—O—(CH 2 ) 2 ).
Dry triethylamine (30.8 mL, 0.22 mole) was added to the mixture of the di-p-toluenesulfonic acid salt of bis-(L-leucine)-1,8-octylene diester (III, R 4 ═(CH 2 ) 8 ) (53.772 g, 0.075 mole), the di-p-toluenesulfonic acid salt of L-lysine benzyl ester (IV) (14.518 g, 0.025 mole) (total amount of (III)+(IV)=0.1 mole), and active bis-carbonate (X) (R 6 ═(CH 2 ) 2 —O—(CH 2 ) 2 ) (43.63 g, 0,1 mole) in dry N,N-dimethylacetamide (DMA) (52.5 mL) (total volume of DMA and NEt 3 is 83.3 mL, concentration 1.2 mol/L by (III)+(IV) or by (X)) at room temperature. Afterwards the temperature of the reaction mixture was increased to about 80° C. and stirred for 16 hours. The viscous reaction solution was cooled to room temperature, and poured into water. The separated polymer was thoroughly washed with water, dried at about 30° C. under reduced pressure. After final purification, yield is 76% up to negative test on pnitrophenol and p-toluenesulfonic acid (see below), η red =0.42 dL/g.
Example 21
Preparation of co-poly-{[N,N′-(3-oxapentylene-1,5-dioxydicarbonyl)-bis-(L-leucine)-1,8-octylene-1,5-oxydicarbonyl)-L-lysine benzyl ester] 0.10 } (21) (compound of formula (XI) wherein m=0.90, p=0.10, R 2 =Bz, R 3 =iso-propyl, R 4 ═(CH 2 ) 8 ), and R 6 ═(CH 2 ) 2 —O—(CH 2 ) 2 ).
Dry triethylamine (30.8 mL, 0.22 mole) was added to the mixture of the di-p-toluenesulfonic acid salt of bis(L-leucine)-1,8-octylene diester (III, R 4 ═(CH 2 ) 8 ) (64.5264 g, 0.09 mole), the di-p-toluenesulfonic acid salt of L-lysine benzyl ester (IV) (5.8072 g, 0.01 mole) (total amount of (III)+(IV)=0.1 mole), and active bis-carbonate (X) (R 6 ═(CH 2 ) 2 —O—(CH 2 ) 2 )(43.63 g, 0,1 mole) in dry N,N-dimethylacetamide (DMA) (52.5 mL) (total volume of DMA and NEt 3 is 83.3 mL, concentration 1.2 mol/L by (III)+(IV) or by (X)) at room temperature. Afterwards the temperature of the reaction mixture was increased to about 80° C. and stirred for 16 hours. The viscous reaction solution was cooled to room temperature, and poured into water. The separated polymer was thoroughly washed with water, dried at about 30° C. under reduced pressure. After final purification up to negative test on p-nitrophenol and p-toluenesulfonic acid (see below) yield is 63%, η red =0.51 dL/g.
Example 22
Deprotection of Polymeric Benzyl Esters (General Procedure)
According to the general procedure described herein for the preparation of coPEAs and coPEURs, the polymers were obtained as the benzyl ester forms. For the preparation of the corresponding polymers having free COOH groups, these polymers having the benzyl esters were subjected to catalytic debenzylation using hydrogen (H 2 ) gas and palladium (Pd) black as a catalyst. Suitable reaction conditions are available, e.g., in T. W. Greene, Protecting Groups In Organic Synthesis ; Wiley: N.Y., 1981; J. March, Advanced Organic Chemistry Reactions, Mechanisms and Structure , (2nd Ed.), McGraw Hill: N.Y., 1977; F. Carey and R. Sundberg, Advanced Organic Chemistry, Part B: Reactions and Synthesis (2nd Ed.), Plenum: New York, 1977; and references cited therein.
(A.) Deprotection of Polymeric Benzyl Esters (coPEAs)
Palladium black catalyst (3.0 g) was added to a solution of the polymer (benzyl ester form) (10 g) in ethanol (100 mL), and dry gaseous hydrogen was bubbled through the solution for about 10 hours to about 20 hours. A magnetic stirrer was used to agitate the solution. After catalytic hydrogenolysis was complete, the reaction mixture was filtered, and clear and colorless solutions were obtained.
(B) Deprotection of Polymeric Benzyl Esters (coPEURs)
Palladium black catalyst (3.0 g) was added to a solution of the polymer (benzyl ester form) (10 g) in ethyl acetate (100 mL), and dry gaseous hydrogen was bubbled through the solution for about 10 hours to about 30 hours. A magnetic stirrer was used to agitate the solution. After catalytic hydrogenolysis was complete, the reaction mixture was filtered, and clear and colorless solutions were obtained.
After deprotection of the polymers, no substantial change of molecular weight or polydispersity was observed. For example, for the compound (2) from Table 3 (i.e., benzyl ester form) the molecular weight characteristics were as follows: Mw=31.300, Mn=21.000, Mw/Mn=1.49. After hydrogenolysis, molecular weight characteristics are: Mw=40.900, Mn=28.000, and Mw/Mn=1.46.
Example 23
Purification of the Benzyl Ester Polymers (General Procedures)
After the polymers were precipitated in water and thoroughly washed with water, the solvent (DMA) and p-toluenesulfonic acid salt of triethylamine were removed (nearly to completion). However, the polymers still contain a significant amount of by-product of the polycondensation (e.g., p-nitrophenol) which was removed as described below.
(A.) Purification of coPEAs
The polymer obtained above (10 g) was dissolved in ethanol (50 mL, 95%). The solution was filtered and the polymer was precipitated in ethyl acetate (1.0 L), where it separates as tar like mass, and was kept overnight in refrigerator. The ethyl acetate was removed and a fresh portion of ethyl acetate (1.0 L) was added to the tar like mass and kept overnight in refrigerator against. This procedure was repeated until a negative test on p-nitrophenol (see below) was obtained. Normally it was repeated for 1-2 times. After such a treatment, p-nitrophenol (which is more soluble in ethylacetate than in water), was nearly completely removed from the polymers. The obtained tar like mass was dried, dissolved in 95% ethanol precipitated in distilled water as a rubber-like mass, and dried at about 60° C. under reduced pressure. Yields of purified coPEAs were up to about 97%.
(B) Purification of coPEURs
The polymer obtained above (10 g) was dissolved in chloroform (100 mL), cast as a thin film onto a cylindrical glass vessel's (d=400-500 mm) inner surface, dried at room temperature, thoroughly washed with water, and dried again. The film obtained was dissolved in dimethylformamide (DMF), and the polymer was precipitated in water. A rubber-like polymer was collected and dried at about 35° C. to about 40° C. under reduced pressure. This procedure was repeated for several times, until a negative test on p-nitrophenol was obtained (see below). Normally it was repeated about 3-4 times. After such a treatment, the yields of coPEURs decreased to ≦80%, however the viscosities increased, which is believed to be the result of the loss of low-molecular weight fractions.
(C.) Purification of Deprotected Polymers (Polyacids)
After deprotection, polymers were purified by precipitation from an ethanol solution in water. A rubber-like mass was collected and dried at room temperature under reduced pressure.
Example 25
4-AminoTEMPO Attachment and its Biodegradation and Free Radicals Release Study
For this study the co-PEA of the following structure was chosen:
(The hydrogenolysis product of the Example 2) which revealed excellent elasticity (elongation at break ca. 1000%) and was used in in vivo “stent experiments”.
4-AminoTEMPO (TAM) was attached to this polyacid using carbonyldiimidazol (Im 2 CO) as a condensing agent In typical procedure 1 g of polyacid was dissolved in 10 mL of purified, freshly distilled chloroform. A molar equivalent of carbonyldiimidazole was added at room temperature and stirred. A molar equivalent of TAM was added, stirred for 4 h, and kept at r.t. overnight The solution was filtered and cast onto a hydrophobic surface. Chloroform was evaporated to dryness. The obtained film was thoroughly washed with distilled water and dried under reduced pressure at r.t. An elastic, light red-brown film was obtained. The degree of TAM attachment was 90-95%, determined by UV spectrophotometry in ethanol solution at 250 nm (Polymer does not absorb at this wavelength).
After TAM attachment, the polymer retained elastic properties. It degraded by lipase according to nearly zero order biodegradation kinetics (that is ideal for drug controlled release devices) while retaining the film's integrity whereas the starting polyacid completely degraded and/or disintegrated within 48 h in slightly alkaline buffer solution in the presence of lipase). TAM attached polymer is designated as GJ-2(TAM).
For the biodegradation study, the film of GJ-2(TAM) was obtained, it was dissolved in 10 mL of chloroform, and a Teflon disk of d=4 cm was covered by this solution for several times and evaporated so that the weight of dried polymeric coating was ca. 500 mg. The disc was placed in a lipase solution (4 mg of the enzyme in 10 mL of phosphate buffer with pH 7.4. 6 mL of the enzyme was dissolved in 15 mL of the buffer—10 mL was used for biodegradation experiment, 5 mL—for the compensation in UV measurements) and placed in thermostat at 37° C. The enzyme solution was changed every 24 h. Every 24 h the film was removed, dried with filer paper and weighed. The buffer solution was analyzed by UV-spectroscopy at 250 nm since the polymeric degradation products don't absorb at this wavelength. The same solution of the enzyme was used for the compensation.
The obtained results indicate that both biodegradation (weight loss) of the polymer and TAM releasing are very close to zero order kinetics.
Since the amide bond through which the TAM is attached to the polymer is rather stable under the biodegradation conditions, it is expected that TAM is released to the polymeric debris. At the same time the calibration curve of TAM in buffer was used for quantitative measurements. Therefore, the amount of TAM (in mg), determined by UV-spectroscopy, corresponds to the free TAM in mg (in mg/equivalent).
After 216 h (9 days) biodegradation polymer lost ca. 11% of the weight, and ca. 8% of the attached TAM was released. This, along with biodegradation and TAM releasing profiles, indicates that the TAM releasing is determined by the erosion of the polymeric film.
The results of the biodegradation (weight loss in mg/cm 2 ) of 4-AminoTEMPO (TAM), attached to a co-PEA of the present invention, and the kinetics of nitroxyl radical release from 4-AminoTEMPO (TAM), attached to a co-PEA of the present invention, are shown in the charts below. FIG. 1 illustrates the biodegradation (weight loss in mg/cm 2 ) of 4-Amino TEMPO (TAM) attached to a representative compound of the present invention. FIG. 2 illustrates the kinetics of nitroxyl radical release from 4-Amino TEMPO (TAM) attached to a representative compound of the present invention.
Example 24
Test on Purity (General Procedure)
The coPEA or coPEUR (200-250 mg) was dissolved in a boiling 10% water solution of NaOH (5.0 mL), and the resulting solution was analyzed using UV-VIS spectrophotometer (Specord UV-VIS, Carl Zeiss, Jena, cell of 4 mL, 1=1,0 cm). The absence of the absorption in the region of 250-280 nm (TosO − ) and at 430 nm (O 2 NC 6 H 4 O − ) indicates that neither p-toluenesulfonic acid nor p-nitrophenol exists in the polymeric sample to any appreciable degree. It is noted that in alkaline media, p-nitrophenol does not absorb in UV region. As such, its absorption does not overlap the absorption of p-toluenesulfonic acid.
The structure of the benzylated polymers prepared in Examples 1-21 is given in the Tables below.
Example 25
TABLE I
(VII)
Compound
R 1
R 2
R 3
R 4
m
p
n
(1)
(CH 2 ) 4
Bz
iso-propyl
(CH 2 ) 6
0.75
0.25
75
(2)
(CH 2 ) 8
Bz
iso-propyl
(CH 2 ) 6
0.75
0.25
65
(3)
(CH 2 ) 4
Bz
iso-propyl and Bz
(CH 2 ) 6
0.75 (0.50 + 0.25)
0.25
—
(4)
(CH 2 ) 8
Bz
iso-propyl
(CH 2 ) 6
0.75 (0.50 + 0.25)
0.25
—
(5)
(CH 2 ) 4
Bz
iso-propyl
(CH 2 ) 6
0.50
0.50
—
(6)
(CH 2 ) 8
Bz
iso-propyl
(CH 2 ) 6
0.50
0.50
—
(7)
(CH 2 ) 4
Bz
iso-propyl
(CH 2 ) 8
0.90
0.10
—
(8)
(CH 2 ) 8
Bz
iso-propyl
(CH 2 ) 4
0.90
0.10
—
(9)
(CH 2 ) 8
Bz
iso-propyl
(CH 2 ) 6
0.90
0.10
—
(10)
(CH 2 ) 8
Bz
iso-propyl
(CH 2 ) 8
0.90
0.10
—
(11)
(CH 2 ) 8
Bz
iso-propyl
(CH 2 ) 12
0.90
0.10
—
(12)
(CH 2 ) 12
Bz
iso-propyl
(CH 2 ) 6
0.90
0.10
—
Example 26
TABLE II
(XI)
Compound
R 2
R 3
R 4
R 6
m
p
n
(13)
Bz
iso-propyl
(CH 2 ) 4
(CH 2 ) 3
0.75
0.25
—
(14)
Bz
iso-propyl
(CH 2 ) 4
0.75
0.25
—
(15)
Bz
iso-propyl
(CH 2 ) 6
(CH 2 ) 3
0.75
0.25
112
(16)
Bz
iso-propyl
(CH 2 ) 6
0.75
0.25
130
(17)
Bz
iso-propyl
(CH 2 ) 6
0.50
0.50
85
(18)
Bz
iso-propyl
(CH 2 ) 6
0.90
0.10
115
(19)
Bz
iso-propyl
(CH 2 ) 8
(CH 2 ) 3
0.75
0.25
—
(20)
Bz
iso-propyl
(CH 2 ) 8
0.75
0.25
—
(21)
Bz
iso-propyl
(CH 2 ) 8
0.90
0.10
—
The physical properties of the polymers prepared in Examples 1-12 are given in Table III.
Example 27
TABLE III
Mw/Mn (GPC
B.W.L.
Tg
Compound
Yield (%)
η red (dL/g)
Mw
Mn
in THF)
B.W.L. (%) 1
B.W.L. (%) 2
(%) 3
(DSC)
(1)
90
1.30
32,100
27,000
1.19
(2)
91
1.40
31,300
21,000
1.49
~0
1-2
1-2
(3)
94
1.40
~0
10
35
(4)
95
0.77
20.6° C.
(5)
93
1.25
(6)
95
1.31
(7)
94
1.21
(8)
95
1.28
(9)
96
1.41
~0
12
38
(10)
97
1.50
27.5° C.
(11)
96
0.68
(12)
96
1.18
(13)
63
0.32
(14)
78
0.58
4.7 4
2.2 5
4.4 6
(15)
60
0.53
50,000
29,900
1.68
5.0 7
7.3 8
8.2 9
(16)
68
0.72
61,900
38,500
1.61
0.4 7
5.6 8
8.9 9
(17)
80
0.45
37,900
22,300
1.70
(18)
70
0.74
56,500
33,700
1.68
(19)
84
0.46
0.9 4
2.0 5
3.7 6
(20)
76
0.42
(21)
63
0.51
1 B.W.L. (%) is biodegradation (weight loss %) at 37° C. after 120 h in phosphate buffer (pH 7.4).
2 B.W.L. (%) is biodegradation (weight loss %) at 37° C. after 120 h in phosphate buffer (pH 7.4) with α-chymotrypsin (4 mg/10 mL of buffer.
3 B.W.L. (%) is biodegradation (weight loss %) at 37° C. after 120 h in phosphate buffer (pH 7.4) with lipase (4 mg/10 mL of buffer).
4 B.W.L. (%) is biodegradation (weight loss %) at 37° C. after 240 h in phosphate buffer (pH 7.4).
5 B.W.L. (%) is biodegradation (weight loss %) at 37° C. after 240 h in phosphate buffer (pH 7.4) with α-chymotrypsin (4 mg/10 mL of buffer.
6 B.W.L. (%) is biodegradation (weight loss %) at 37° C. after 240 h in phosphate buffer (pH 7.4) with lipase (4 mg/10 mL of buffer).
7 B.W.L. (%) is biodegradation (weight loss %) at 37° C. after 180 h in phosphate buffer (pH 7.4).
8 B.W.L. (%) is biodegradation (weight loss %) at 37° C. after 180 h in phosphate buffer (pH 7.4) with α-chymotrypsin (4 mg/10 mL of buffer.
9 B.W.L. (%) is biodegradation (weight loss %) at 37° C. after 180 h in phosphate buffer (pH 7.4) with lipase (4 mg/10 mL of buffer).
The benzylated polymers obtained had high Mw in the range 30,000-60,000 and narrow polydispersity—Mw/Mn=1.2-1.7 (Determined by GPC for the polymers, soluble in THF), and possess excellent film-forming properties. They revealed rather low glass transition temperature (Tg=9-20° C.). The polymers are soluble in common organic solvents like chloroform (all of them), ethanol, (copoly(ester amide)s), ethylacetate (copoly(ester urethane)s), some of them in THF. Both co-PEAs and co-PEURs reveal rather high tendency to in vitro biodegradation. Co-PEAs are more inclined to specific (enzyme catalyzed) hydrolysis, whereas co-PEURs showed the tendency to both specific and non-specific (chemical) hydrolysis.
Example 28
In Vitro Biodegradation Study
In vitro biodegradation studies were performed by weight loss. Standard films with d=4 cm and m=450-550 mg (pure films in case of non-contractive poly(ester amide)s and films on Teflon backing in case of contractive poly(ester urethane)s), were placed into the glass vessels continuing 10 mL of 0.2 M phosphate buffer solution with pH=7.4 (either pure buffer or buffer containing 4 mg of an enzyme—α-chymotrypsin or lipase) and placed at 37° C. The films were removed from the solutions after a predetermined time, dried with filter paper and weighted. Buffer or enzyme solution was changed every 24 h.
All publications, patents, and patent documents are incorporated by reference herein, as though individually incorporated by reference. The invention has been described with reference to various specific and preferred embodiments and techniques. However, it should be understood that many variations and modifications may be made while remaining within the spirit and scope of the invention | The invention provides elastomeric copolyester amides, elastomeric copolyester urethanes, and methods for making the same. The polymers are based on α-amino acids and possess physical, chemical and biodegradation properties that render them suitable for use in the human body. The polymers are useful as carriers of drugs or other bioactive substances. The polymers can also be linked, intermixed, or a combination thereof, to one or more drugs. Additionally, the polymers can be used to coat stents, for example, to suppress restenosis. Furthermore, the biodegradation of the copolyester amides and copolyester urethanes allows for the delivery of essential α-amino acids to sites in the body, for example, to facilitate wound repair of injured tissues. | 2 |
TECHNICAL FIELD
This invention relates generally to a system and method for completing a call over a virtual private line and specifically to a method and system for eliminating the "glare" which occurs when both parties attempt to initiate a call simultaneously over a virtual private line.
BACKGROUND OF THE INVENTION
Virtual private line communication is a service offered by some communication carriers that provides features and functionality similar to the well-known service of dedicated Private Line Automatic Ring-down (PLAR) between two end points. The virtual private line service (also known as "virtual hot line") was designed to replace, cost effectively, the expensive PLAR service that establishes a permanent point-to-point physical connection between two communication devices. Accordingly, the major features of PLAR, such as very short call setup time and secure communication between a calling and a called party, are also offered in the virtual private line service. Unlike PLAR, a virtual private line uses, as part of a communication switching system, a common software defined network to connect via trunks both ends of a circuit for the purpose of allowing an automatic connection to be established for the duration of a call, upon origination from either end. Subscribers of the virtual private line service, such as security traders in the financial industry, governmental security agencies and the armed forces attach a very high degree of importance to the "almost instantaneous connection" requirement of the service. To that end, most carriers have implemented a design wherein the mere lifting of a station's handset by the calling party automatically and virtually instantaneously results in a ringing tone at the called party's telephone set.
Equally important to virtual hot line subscribers is the requirement of guaranteed access to the party at the other end of the line. More specifically, subscribers of this service want the phone at one end of the line to always ring without any possibility of a busy tone upon lifting of the handset by a caller at the other end of the line. Dedicated private lines, by virtue of the permanent physical connection between the two communicating devices, can guarantee their subscribers access to parties at either end of the line. Aiming to meet this requirement for virtual private lines, in U.S. Pat. No. 4,982,421 issued on Oct. 27, 1989 to Kirsch et al. the inventors of that patent disclose a system for virtual private lines that uses non-dialable routing numbers devised by a software defined network to establish a connection between the two ends of the line. The use of the non-dialable routing number technique allows each end of the virtual private line connected to an access/egress switch to reach and to be reached only by the other end of the circuit because other potential calling parties have no way of activating the non-dialable routing number. Thus, the Kirsch et al. system partially meets the guaranteed access requirement of virtual private line subscribers by preventing inadvertent and unwanted calls from external parties who are not connected to the virtual private line from blocking access to the circuit. However, neither the Kirsch et al. system nor any other system in the prior art can prevent the software defined network from emitting busy signals in the instance of a "simultaneous" trunk seizure condition that occurs when both stations of the virtual private line try to establish a connection simultaneously (i.e. within the range of call setup time). This deficiency, which is called "glare", takes special significance when one considers that higher-than-usual incidences of busy signals can be reasonably expected for virtual private line service, since both parties would tend to initiate calls using the hot line within the same time window upon occurrence of special events requiring immediate communication between the parties.
SUMMARY OF THE INVENTION
In accordance with our invention, a system and method are disclosed to prevent busy tone signals from reaching the station sets and to complete a call over a virtual private line when both ends of the line "simultaneously" attempt to initiate a call. A "simultaneous" call attempt for a virtual private line can occur within the time window delimited by 1) the emission of an off-hook signal on one end of the line followed by attendant call setup delay, and 2) trunk seizure at the other end of the line caused by reception of an off-hook signal. In our invention, the simultaneous trunk seizure is first detected by one or more components of the communication switching system before the callers receive any busy tone signals. While callers are still off-hook, access and egress trunks are cleared by the emission of terminating supervisory signals by the same component(s) which detected the simultaneous trunk seizure condition. Once the links (meaning trunks or lines) are cleared, a new call is reinitiated by one component connected to one station set sending an originating supervisory signal towards the other station set, typically using a signaling network interconnecting some components of the communication switching system also called a communication switching complex.
According to one embodiment of our invention, before busy tone signals can be received by the calling parties, a simultaneous trunk seizure condition is detected by each switch which serves each station and constitutes part of the communication switching system that sets up the virtual private line. The detection of the simultaneous trunk seizure condition triggers the release by each switch of a message over the signaling network connecting the switches. This message, which is a terminating supervisory signal directed from one switch to the other, indicates that the access and egress trunks of the virtual private line have to be cleared. Upon reception of that message, each switch relinquishes control of the link connecting it to the station set in order to free that trunk for a new call from the station at the other end of the line. After a short pause to insure that both trunks have been cleared, one of the switches reinitiates the call by sending to the other switch, via the signaling network, a new call initiation message in the form of an originating supervisory signal. Embedded in the call initiation message is a non-dialable routing number for the call derived from the translation of the access line identification number to a routing number. After receiving the new call initiation message, the egress switch translates the routing number embedded in that message to the trunk identification number of the egress trunk using well-known table look-up techniques. Once the egress trunk is identified, the egress switch seizes that trunk to establish a communication path between both stations of the virtual private line to complete the call. The determination of which switch reinitiates the call can be based on some arbitrary criteria, such as the logical address assigned to each switch by the signaling network.
In another embodiment of our invention, signal converters, each placed between a station and the switch serving that station, are used (instead of the switches themselves) to clear the trunks and reinitiate the call. In this embodiment, once the busy tone signal is detected by the signal converters, both converters send terminating supervisory signals, such as on-hook signals, towards their respective switches, thereby clearing both access/egress trunks and terminating both simultaneously attempted calls. After a short pause to insure that both trunks have been cleared, a predetermined signal converter designated as a "dominant" converter, reinitiates the call by sending an off-hook signal towards its serving switch while the other converter, designated as a subservient converter, stays passive with respect to setting up the call. The switch serving the dominant converter uses the routing number derived from its own routing table to send a call initiation message to the switch connected to the subservient converter to complete the call. Subsequent actions follow the pattern described above in the first embodiment of the invention.
In the instance when both access and egress trunks of the virtual private line are connected to the same switch, the access and egress ports of that switch detect the simultaneous trunk seizure before the calling parties become aware of such condition. In that case, the switch instructs its ports attached to the access/egress trunks to relinquish control of those trunks, thereby terminating both simultaneously attempted calls. Then, the switch reinitiates the call by seizing the access and egress trunks and translating the routing number to the trunk identification number of the egress line, thereby establishing a communication path between its access and egress ports of the virtual private line.
BRIEF DESCRIPTION OF THE DRAWING
In the drawings:
FIG. 1 shows, in block diagram form, a communication switching system designed to eliminate glare resulting from simultaneous trunk seizure in a virtual private line in accordance with our invention;
FIG. 1A depicts a switch arranged to eliminate glare due to simultaneous trunk seizure in virtual private lines;
FIG. 1B shows an illustrative communication switching system arranged to eliminate glare caused by a simultaneous trunk seizure condition in a virtual private line;
FIG. 2 is a flowchart outlining different steps performed by various components of a communication switching system resulting in simultaneous trunk seizure over a virtual private line;
FIG. 3 presents, in flow diagram format, actions taken and decisions formulated by the switch(es) of a communication switching system to establish a connection in case of simultaneous trunk seizure;
FIG. 4 represents a flow diagram of actions taken and decisions formulated by the signal converters of a communication switching system to establish a connection over a virtual private line in case of simultaneous trunk seizure;
FIG. 5 shows a graphical representation of signals and call processing messages sent over a software defined network. FIG. 5 also depicts the time window within which simultaneous trunk seizure can occur when one party attempts to originate a call after the outgoing trunk has been reserved by the switch at the other end of the line for the purpose of completing a call;
FIG. 6 shows a signal converter arranged in accordance with our invention;
FIG. 7 shows a set of instructions stored in the memory of a signal converter; and
FIG. 8 displays a set of instructions stored in the memory of a switch.
DETAILED DESCRIPTION
FIG. 1 shows, in block diagram form, a configuration for a communication switching system designed to eliminate glare in a virtual private line arrangement. In FIG. 1, station sets 101 and 102 are shown linked via access/egress lines 103 and 104 to signal converters 105 and 106, respectively. The latter are connected via access/egress trunks 107 and 108 to communication switching system 100 comprised of switches 110 and 120 and a signaling network represented by Signal Transfer Point (STP) 130. Switches 110 and 120 are processor-controlled, software-driven switching systems that operate as points of access to and points of egress from, communication switching system 100 for station sets 101 and 102 at both ends of the virtual private line. They also serve as access points to a Common Channel Signaling network (represented as described below by STP 130) for communication switching switching system 100. Signal processors 118 and 128 in switches 110 and 120, respectively, are wired-logic processing units that a) scan for supervisory changes and b) receive and transmit signals to other switches directly through intermachine trunk 131 or via the signaling network represented by STP 130. Central processors 119 and 129 in switches 110 and 120, respectively, provide path information to route a call over the network. Switches 110 and 120 may be implemented using the AT&T No. 4ESS switch or the AT&T 5ESS™ switch. A detailed description of the structure of the AT&T 5ESS™ switch is provided in AT&T Technical Journal, Vol. 64, No. 6, part 2, pp. 1305-1564, July/August 1985. The features and functionality of the AT&T No. 4ESS switch are explained extensively in Bell System Technical Journal (BSTJ), Vol. 56, No. 7, pp. 1015-1320, September, 1977. In addition, the Kirsch et al. U.S. Pat. No. mentioned earlier discloses the structure of a No. 4ESS switch within the context of a virtual private line service using a software defined network.
When switch 110 (120) acts as an access switch, it translates off-hook signals received from station 101 (102) to a non-dialable routing number by accessing routing table 111 (121). Routing tables 111 and 121 are translation tables, each of which correlates a routing number to a trunk identification number. Conversely, when switch 110 (120) acts as an egress switch, it translates the routing number received from access switch 110 (120) to the trunk identification number of the egress trunk by accessing customer routing block 112 (122). Alternatively, a translation table in each switch-called a customer data block-can, as explained in the Kirsch et al. patent, match the identification number of an incoming trunk to a non-dialable Automatic Number Identification (ANI) which is forwarded to a routing database in the network. The routing database, in turn, translates the ANI to a routing number associated with the trunk identification number of the station at the other end of the line.
In addition to all the functionality mentioned above, switches 110 and 120 can also perform call maintenance and terminations functions described below.
Switches 110 and 120 exchange call handling messages via a data network called the Common Channel Signaling network. The latter is a packet switching network composed of a plurality of interconnected nodes called Signal Transfer Points (STPs) that are used to exchange call handling messages between switches according to a specific protocol, such as CCS7. However, for the sake of simplicity, the signaling network is represented in FIG. 1 by a single Signal Transfer Point, namely STP 130. The features and functionality of an STP are described in the book "Engineering and Operations in the Bell System, " Second Edition, pp 292-294, AT&T Bell Laboratories Inc., 1982
Signal converters 105 and 106, which may be implemented, for example, as stand alone units or as circuit packs within a D4 channel bank, perform two primary functions. The first function is needed when stations 101 and 102 in FIG. 1 are analog, and access/egress switches 110 and 120 are digital. In that event, signal converters 105 and 106 are arranged to convert analog loop start/ground start signals received from the analog station sets to digital bit streams in a specific format (such as E&M) ordinarily used in digital switches. Similarly, digital bit streams from switches 110 or 120 are converted into analog signals recognizable by the analog station sets. The analog to digital conversion function is not needed when both ends of the virtual private line are connected to digital telephone sets.
Secondly, signal converters 105 and 106 provide call setup and call termination maintenance functions to avoid misinterpretation of signals exchanged between stations 101 and 102 and switches 110 and 120, at the beginning and at the end of conversations between the parties using the virtual private line. For example, if, at the end of a conversation, one of the parties delays hanging up the phone, that delay could be erroneously interpreted as a new off-hook condition indicating a request to initiate a new call. To avoid this situation, the signal converter connected to that station must send an on-hook signal to the switch to avoid false ringing at the far end station. Other examples of call set-up and termination maintenance functions performed by signal converters 105 and 106 include provisions for early call abandonment, and proper "tearing down" of connections at call termination time. The call setup and termination functions performed by signal converters 105 and 106 are needed for analog as well as digital stations. As mentioned above, the call maintenance and termination functions can also be performed by switches 110 and 120.
Before explaining in detail how the glare condition is cured and how a new call is reinitiated transparently to the callers in accordance with our invention, a general description of the processes that lead to a simultaneous trunk seizure condition in a virtual hot line arrangement using signal converters will provide continuity and clarity to the rest of this disclosure.
Referring to FIG. 2, the call initiation process is set in motion, in step 201, by a caller at station set 101 (for example) lifting the handset, which causes an off-hook signal to be received by signal converter 105 via access/egress line 103. Signal converter 105 then forwards the off-hook signal to switch 110 via access/egress trunk 107. Within the same call setup time range, a caller lifts the handset of station set 102 causing an off-hook signal to be sent via access/egress line 104 to signal converter 106, which forwards that signal to switch 120. From that point on, the process becomes totally bilateral, i.e. the functions performed in this process are carried out separately by each switch and its attendant components independently of similar functions performed concurrently by their counterparts at the other end of the virtual private line. Furthermore, the same switch plays two different roles in this process. For example, switch 110 is an access switch for station set 101 but plays the role of an egress switch for station set 102. Conversely, switch 120 is an access switch for station set 102 but represents an egress switch for station set 101. In step 202, signal processors 118 and 128 in switches 110 and 120 respectively, recognize the off-hook signals received from station sets 101 and 102 as an attempt to originate a call. Accordingly, in step 203, switches 110 and 120 use routing tables 111 and 121 respectively to translate the incoming trunk ID of access lines 103 and 104 into a non-dialable routing number. Then in step 204, each switch independently starts the call set-up process by sending over the signaling network an Initial Address Message (IAM) to its counterpart egress switch, namely, switch 110 or switch 120. An IAM is a signal sent by an access switch to an egress switch for the purpose of initiating trunk seizure of an egress trunk. An IAM ordinarily contains a routing number and other information necessary for the routing and handling of a call. After receiving the non-dialable routing number in the IAM, signal processors 118 and 128 send instructions to central processors 119 and 129 to use data stored in Customer Routing Block 112 and 122 to translate the non-dialable routing number to the trunk identification number associated with trunks 107 and 108 respectively. Once the trunk ID numbers of egress lines 107 and 108 are identified, central processors 119 and 129 try to reserve access/egress lines 103 and 104 to complete the call by attempting to seize them. Upon finding that egress trunk 107 or 108 has already been seized, switch 110 and 120 in step 205, return an "egress busy" message to the access switch.
As mentioned above, our invention can be implemented in two alternative embodiments. The first embodiment uses the call processing capabilities of switches 110 and 120 to eliminate glare, while the second embodiment takes advantage of the signal detection and generation features of signal converters 105 and 106 in FIG. 1. A description of the different steps performed by switches 110 and 120 leading to call completion over the virtual private line is provided in FIG. 3, while FIG. 4 describes the actions and decisions taken by signal converters 105 and 106 to complete the call.
A. Switch Implementation
Referring to FIG. 3, the detection of the busy line condition by signal processors 118 and 128 causes access switch 110 and 120, in step 301, to send a "RELEASE COMPLETE" signal to egress switch 110 or 120. A "RELEASE COMPLETE" message is a standard signal ordinarily triggered by emission of an on-hook signal, directing the port of a switch to relinquish control of an egress trunk for the purpose of freeing the trunk for subsequent calls. The end result of the "RELEASE" messages is to clear access/egress trunks 107 and 108 in step 302, thereby terminating both simultaneously attempted calls, paving the way for a new call to be initiated without the callers having to go on-hook. Once control of access/egress trunks 107 and 108 is relinquished by switches 110 and 120, an arbitrary but uniform scheme for all switches in the communication switching system determines which switch will reinitiate the call. For example, switches 110 and 120 can exchange messages indicating the value of their respective logical address assigned by the signaling network. In step 303, the logical addresses are compared to determine which switch has the higher address. In steps 304 and 305, the switch with the higher address sends a new Initial Address Message (IAM) over STP 130 to the other switch to initiate a new call. Assuming that switch 110 has a higher logical address than switch 120, then switch 110 in step 303 or 304 sends the routing number associated with egress trunk 108 to switch 120. The latter matches the received routing number to the trunk identification number associated with egress trunk 108 in Customer Routing Block 122. Switch 120 then seizes egress trunk 108 and in step 306, sends an acknowledgement message to switch 110 indicating that the call can be routed over communication switching system 100 to station set 102. In step 307, the call is routed over communication switching system 100. In this embodiment of our invention, the call maintenance and termination functions described above for the signal converters, are ported to switches 110 and 120.
Alternative implementations of the system shown in FIG. 1 are illustrated in FIG. 1A and FIG. 1B. A single switch example of the invention is depicted in FIG. 1A. Shown in FIG. 1B is a block diagram of a communication switching system arranged to implement the invention for the limited cases in which the call setup and termination maintenance functions are implemented in switches 160 and 170.
Before explaining the second embodiment of our invention, a detailed description of a signal converter, which plays a key role in that embodiment may be helpful.
As shown in FIG. 6, the signal converter depicted in that drawing is comprised of modular elements which include trunk interface 601, line interface 602, signal detector/generator 603, and processor 604.
The function of trunk interface 601 is to provide the signal converter of FIG. 6 with trunk receiver and trunk transmitter capability. Trunk receiver 610 recovers a 64 kb/s signal from trunk physical interface 614 and demultiplexes it into voice frequency information and signaling information, including originating and terminating supervisory signals. The voice frequency information is forwarded to signal detector/generator 603 and the signaling information is passed to processor 604. Trunk transmitter 611 multiplexes voice frequency information from line interface 602 and signaling information from processor 604 for transmission on trunk 600 via trunk physical interface 614.
The function of line interface 602 is to provide the signal converter of FIG. 6 with line receiver and line transmitter capability. Line receiver 613 recovers a 64 kb/s signal from line physical interface 615 and demultiplexes it into voice frequency information and signaling information. The voice frequency information is provided to trunk transmitter 611 in trunk interface 601 while the signaling information is provided to processor 604. Line transmitter 612 multiplexes data from signal detector/generator 603 and signaling information from processor 604 for transmission on line 616 via line physical interface 615.
The function of signal detector/generator 603 is to scan for busy signals within the data received from trunk interface 601 by periodically monitoring all signals coming from trunk 600 using well-known sampling techniques. In addition, signal detector/generator 603 generates audible call progress tones (such as ringing) for transmission to line interface 602 and provides a connection between trunk interface 601 and line interface 602. The components of signal detector/generator 603 include signal detector 605, tone ringer 608, and selector 606. Signal detector 605 continuously monitors trunk interface 601 to report to processor 604 any incoming busy signal sent by switches 110 and 120 via trunk interface 601. Tone ringer 608 generates audible ringing signals and transmits those signals to selector 606. Selector 606 plays the role of a switch for signal detector/generator 603. It connects trunk interface 601 with line interface 602 and also provides a communication path between tone ringer 608 and line interface 602. Processor 604 is comprised of Central Processing Unit (CPU) 607 and memory storage facilities such as Electrically Erasable Programmable Read-Only Memory (EEPROM) represented by EEPROM 609. Processor 604 executes instructions stored in EEPROM 609 to perform call setup and termination functions. In addition, processor 604 coordinates timing of signals to and from trunk interface 601 and line interface 602, permitting the completion of calls over the virtual private line. EEPROM 609 also stores the internal logic of the converter. A sample of the instructions stored in EEPROM 110 is provided in FIG. 7.
B. Signal Converter Implementation
The steps describing how our invention is implemented in the signal converters are discussed in FIG. 4 and pictorially shown in FIG. 5. FIG. 4 provides a step by step description of the glare elimination process while FIG. 5 offers a more functional and symmetrical description of the same process.
Referring to FIG. 4, the simultaneous trunk seizure condition causes switches 110 and 120 to send busy tone signals to station sets 101 and 102. Those busy signals are detected by signal detector 605 and subsequently blocked in step 401, by selector 606 of signal converters 105 and 106 before those signals can reach station sets 101 and 102. Signal converters 105 and 106, in step 402, use processor 604 to send on-hook signals to switches 110 and 120. In addition, signal converters 105 and 106 send ringing signals to station sets 101 and 102. The on-hook signal is interpreted as a "RELEASE" message by switches 110 and 120 which return "RELEASE COMPLETE" messages back to the signal converters. The net effect of sending the on-hook signals to switches 110 and 120 is that those switches relinquish control of access/egress trunks 107 and 108, thereby terminating the initially attempted calls. In step 403, signal converters 403 and 404 pause for about 600 milliseconds or less to allow the line to be cleared at both ends. In step 404, each signal converter uses processor 604 to check the value of the status indicator flag stored in EEPROM 609 of the converter to determine if the signal converter is dominant or subservient. The value of the status indicator flag is set in advance when the virtual private line is established. This is accomplished for example, by assigning a value of "1" to the status indicator flag to designate a signal converter as a dominant converter, while a value of "0" is used to identify a signal converter as a subservient converter. Unlike switches which can serve multiple virtual private lines and which can be paired to a plurality of other switches to provide virtual private line service to various subscribers, a pair of signal converters is dedicated to each virtual private line. Accordingly, the function of reinitiating a call has to be assigned on a predetermined basis to one of the signal converters. In step 405, the dominant converter sends an off-hook signal to its serving switch to reinitiate the call. For example, if signal converter 105 is the dominant converter, then it would use processor 604 to send an off-hook signal to switch 110 which would reinitiate the call by sending a new Initial Address Message (IAM) to switch 120. In step 406, the call is routed pursuant to call processing techniques described in the Kirsch et. al. patent mentioned earlier.
Referring to FIG. 5, that drawing shows a graphical representation of 1) changes in different components of the network, as two simultaneously initiated calls progress independently towards a simultaneous trunk seizure condition, and 2) how the new call is initiated and completed over the virtual private line. FIG. 5 displays time on the vertical axis, with events occurring first appearing above later occurring events. Looking at FIG. 5 from a vertical perspective, it can be observed that each column in FIG. 5 from top to bottom indicates changes over time in the logical state of a component or of links between components of a communication switching system arranged in accordance with our invention.
With respect to the horizontal dimension, each column in FIG. 5 has a demarcation line indicated by the name of a component instigating or being the object of the change, such as 1) station 101 in the upper left hand corner, 2) dominant signal converter 105 located on the right hand side of station 101, 3) switches 110 and 120 in the middle of the top row, 4) station 102 in the upper right hand corner and finally, 5) subservient signal converter 106 on the left hand side of station 102. Thus, a horizontal view of FIG. 5 shows the flow of a call over a virtual private line as it traverses different links and components of a communication switching system arranged in accordance with our invention.
In FIG. 5, changes triggered by an off-hook signal from station 101 are depicted with solid lines, while similar changes due to an off-hook signal from station 102 are distinguished from the former by broken lines. FIG. 5 makes it easy to see graphically, the process by which a simultaneous trunk seizure condition can occur. Significant events in the process are identified by numerals within each column. For example, event 1-1, is triggered by a change from an on-hook to an off-hook condition for station 101 at time t 0 . The off-hook signal sent at t 0 by station 101 to dominant signal converter 105 causes a change from idle to busy in the link between the station and the signal converter. Thereafter, at time t 1 (t 1 >t 0 ), the transmission of the off-hook signal by dominant signal converter 105 to switch 110 in event 2-1, causes a change in the state of the trunk between dominant signal converter 105 and switch 110 from idle to seized.
At some time t 2 after t 1 , station 102 also goes off hook in event 1-2. As a result, in event 2-2, signal converter 106 transmits the off-hook signal received from station 102 to switch 120, thereby causing a change in the state of the trunk between converter 106 and switch 120 from idle to seized at time t 3 .
Switches 110 and 120 each now communicate with one another, in events 3-1 and 3-2, in order to set up the call. When switch 120 signals switch 110, it determines at time t 4 that the egress trunk to complete the call has already been seized. By the same token, when switch 110 signals switch 120, it determines at time t 5 that the egress trunk to station set 102 has also been seized. An attempt is now made by each switch in events 4-1 and 4-2 to communicate the busy status back to its associated originating station. Thus, in event 5-1, switch 110 applies a busy tone to the trunk connecting it to the dominant signal converter 105. Likewise, in event 5-2, switch 120 applies a busy tone to the trunk linking it to subservient signal converter 106. Thus, from FIG. 5, it can be observed that a simultaneous trunk seizure condition occurs when stations 101 and 102 attempt to initiate calls within a call set up time window of length t cs , which is the longer of the time intervals between (t 3 -t 1 ) and (t 5 -t 2 ) i.e., the time interval during which a busy signal may occur and a virtual hot line call cannot be completed.
FIG. 5 illustrates the bilateral aspect of the signal converter implementation of our invention. The simultaneous trunk seizure condition causes in events 5-1 and 5-2, emission of busy tone signals by switches 110 and 120. The busy tone signals are detected in events 6-1 and 6-2 by signal detectors in the dominant and subservient converters which proceed in events 7-1 and 7-2, to send on-hook signals to their respective serving switches namely, switches 110 and 120 respectively. Upon reception of the on-hook signals by their signal processor (118 and 128), switches 110 and 120 send "RELEASE COMPLETE" messages to each other, to relinquish control of the egress trunks and, thereby effectively terminating the attempted initial calls. Signal converters 105 and 106 then, determine which one will reinitiate the call by checking the status indicator flag as described above. FIG. 5 shows the signal converter linked to station 101 as the preselected dominant converter. FIG. 5 also graphically illustrates the difference in time between the two detection occurrences 6-1 and 6-2, wherein event 6-2 occurs some time after event 6-1 has taken place. Because of the time difference in the detection of the busy signals, the dominant converter is arranged to pause for a predetermined time interval, typically less than 600 milliseconds, to insure that both ends of the line are free, before sending an off-hook message to switch 110 for the purpose of initiating a new call, which is set up and routed using techniques described in the Kirsch et. al. patent mentioned earlier.
With this invention, virtual private line service can now offer the same features and functionality of dedicated private lines in a manner that is operationally transparent to the subscribers at a fraction of the cost. In addition, the switch embodiment of our invention, by using arbitrary criteria to determine the switch that reinitiates the call, offers communication carriers the flexibility of pairing any set of switches in their network to provide virtual private line service to their subscribers. Conversely, the signal converter embodiment of our invention provides a glare elimination solution that may be quickly implemented in a circuit pack within a D4 channel bank. Thus, the signal converter embodiment offers communication carriers a solution to eliminate glare that can be quickly implemented without any disruption of a carrier's communication switching system that may negatively impact delivery of other communications services.
The above description is to be construed as only an illustrative embodiment of this invention. Persons skilled in the art can easily conceive of alternative arrangements providing functionality similar to our invention without any deviation from the fundamental principles or the scope of this invention. | This application discloses a system for eliminating a busy line condition and completing a call over a virtual private line when the stations at each of the lines attempt to initiate a call simultaneously. The system is implemented in three phases. In a first phase, the busy line condition is detected by either the communication switching system which sets up the virtual private line or by two signal converters, each connected to a station set at each end of the line. In a second phase, the switching system or the converters send terminating supervisory signals towards each station to terminate the attempted initial calls while the stations are still off-hook. In a third phase, a predetermined signal converter or a selected switch in the communication switching system initiates a new call by emitting an originating supervisory signal while the stations are still off-hook. | 8 |
FIELD OF THE INVENTION
This invention relates to injection molding, and more particularly to an apparatus and method for removing internally threaded plastic parts, such as container closures, from the mold core of an injection mold.
BACKGROUND OF THE INVENTION
Injection molding generally involves introducing molten plastic under pressure into a space defined between a core part and a cavity part of an injection mold. The molten plastic injected into the space is allowed to coot and thereby solidify to form a “part”, after which the core and cavity parts are separated. The part generally shrinks a small amount upon cooling and remains on the core part of the mold from which it must be removed or “stripped”.
The removal of internally threaded parts from a threaded core has in the past presented a problem. Parts with shallow threads may sometimes be forced off the core using a stripper plate. However, deeper threads would be damaged by any effort to force them off the core with a stripper plate, and therefore are preferably removed by rotation or “unthreading” of the part from the core.
A number of devices and methods are known for simultaneously unthreading and pushing a threaded part from a mold core. One example of such a device is described in U.S. Pat. No. 5,383,780 (McCready et al.). The McCready apparatus includes a rotatable stripper ring which surrounds the mold core. After the part is formed and the mold is opened by separating the cavity part from the mold core, the stripper ring is rotated and simultaneously lifted relative to the core, simultaneously unthreading and pushing the threaded part away from the core. It is also known in the prior art to provide a rotatable core which is unthreaded from the part. Examples of patents which utilize a rotatable core are U.S. Pat. No. 2,306,205 (Crosman, Jr.) and Japanese Patent Application No. 62-264923.
Known devices for stripping threaded parts from a mold core have numerous disadvantages, such as increasing the size and complexity of the molding apparatus and reducing the speed of the molding process. Increased complexity can result in increased equipment and maintenance costs, while increased size can limit the number of mold levels which may be accommodated in a molding apparatus.
Accordingly, an improved method and apparatus for removing threaded parts from plastic injection molds is required.
SUMMARY OF THE INVENTION
The present invention overcomes the above-described problems of the prior art by providing an apparatus and a method for removing threaded parts from plastic injection molds. In the apparatus of the present invention, the cavity part of the mold is rotatable relative to the core part, such that simultaneous rotation of the cavity and opening of the mold results in unthreading of the part from the core.
The apparatus for forming threaded molded parts according to the present invention comprises a first mold plate and a second mold plate. The apparatus has a mold closed position in which a mold is defined comprising the mold core and the mold cavity, and a mold open position in which the mold core and mold cavity are separated by a sufficient distance so as to permit removal of the part from the apparatus. The first mold plate (also referred to herein as the mold core plate) carries the mold core, the core having an external threaded surface. The second mold plate (also referred to herein as the mold cavity plate) carries the mold cavity, which is rotatable about a mold axis parallel to the direction of relative movement of the mold plates.
The mold cavity is rotationally coupled to a mold cavity rotator which is preferably driven by means of a rack. The rotation of the mold cavity is timed with the mold opening step such that the threaded part is unthreaded from the core as the mold plates are separated. The rotator for the mold cavity preferably comprises a rotatable shaft and a radially extending drive pinion. The shaft has gear teeth and is driven by the rack. Thus, movement of the rack results in rotation of the drive pinion, which meshes with a pinion extending radially about the mold cavity, causing rotation of the mold cavity.
The apparatus according to the invention preferably also includes a third mold plate (also referred to herein as the mold stripper plate) which carries a stripper ring. The stripper ring is axially movable relative to the core and is used to eject the part from the core after it is completely unthreaded. Preferably, the stripper ring is provided with at least one air passage through which pressurized air can be passed to assist in ejecting the unthreaded part from the core.
Since the part is unthreaded by the rotating mold cavity, it is desirable to prevent the part from rotating relative to the mold cavity during unthreading. Plastic closures for containers typically have an outer serrated surface to assist in unscrewing the closure from the container. These serrations on the part correspond to serrations provided on an inner axial surface of the mold cavity and advantageously provide sufficient resistance to relative rotation of the part and the mold cavity during unthreading.
In order to ensure that the part becomes separated from the mold cavity after it is unthreaded from the core, the apparatus preferably includes means to hold the part to the core until after the part is substantially completely unthreaded and the mold cavity is withdrawn from the part. In a preferred aspect of the invention, a negative pressure is created in a space which is formed between the part and the mold core as the part is unthreaded, and preferably near the end of the unthreading operation. This negative pressure is preferably applied through an air passage extending through the core.
The apparatus and method for forming threaded molded parts have a number of advantages over the prior art. Firstly, the mechanism for rotating the mold cavity is relatively simple, which can reduce equipment and maintenance costs and improve reliability. Secondly, the mechanism for rotating the mold cavity is relatively compact, permitting it to be housed in a single mold plate. This may permit a greater number of mold levels to be stacked in the press of an injection molding apparatus. Thirdly, in the apparatus and method of the invention, the part is unthreaded from the core as the mold plates are separated, eliminating the need for a separate mold opening step, thus improving the speed of the molding process.
BRIEF DESCRIPTION OF THE DRAWINGS
Preferred embodiments of the invention will now be described, by way of example only, with reference to the accompanying drawings, in which:
FIG. 1 is a sectional view through a preferred apparatus according to the present invention in the “mold closed” position;
FIG. 2 is a sectional view through the apparatus of FIG. 1 after unthreading of the part from the core;
FIG. 3 is a sectional view through the apparatus of FIG. 1 in the “mold open” position, and prior to ejection of the part from the core;
FIG. 4 is a sectional view through the apparatus of FIG. 1 after ejection of the part by the stripper ring; and
FIG. 5 is a perspective view of a part which is molded in the apparatus of FIG. 1 .
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
A preferred apparatus according to the present invention is generally indicated by reference numeral 10 in the drawings. The apparatus 10 comprises three mold plates, namely a mold core plate 12 , a mold cavity plate 14 and a mold stripper plate 16 . A mold core 18 is mounted in the mold core plate 12 , a mold cavity 20 is rotatably mounted in the mold cavity plate 14 , and an annular stripper ring 22 is mounted in the mold stripper plate 16 and surrounds the mold core 18 . The apparatus 10 further comprises a gate insert 24 including an injection nozzle 26 through which molten plastic is supplied into the mold.
In the mold closed position shown in FIG. 1, the mold cavity 20 and the stripper ring 22 engage one another along line A, and the core plate 12 and the stripper plate 16 engage one another along line B. The mold core 18 defines an inner surface of the part 30 , and the mold cavity 20 , stripper ring 22 and gate insert 24 together define an outer surface of the part 30 mold 28 in which a part 30 is formed.
In the preferred embodiment of the invention shown in the drawings, the part 30 comprises an internally threaded closure, such as a threaded lid for a container. The inner surfaces of the threaded part 30 are defined by the mold core 18 , which has an external threaded surface 32 extending generally parallel to mold axis M and a planar surface 34 transverse to the mold axis. The mold core 18 preferably comprises a mold core body 38 having a depression in its upper surface in which is received a generally cylindrical core insert 40 having a side wall 42 . Internal passages 44 are provided through the core body 38 and core insert 40 for coolant circulation and an air passage 46 extends along the mold axis upwardly through the core body 38 and into the core insert 40 , where it is redirected to an opening provided in the side wall 42 of core insert 40 . The air passage 46 thereby communicates with an annular venting gap 48 between the core body 38 and core insert 40 . Venting gap 48 opens into the mold 28 and permits escape of air from the mold 28 during injection of plastic. However, gap 48 is sufficiently narrow that molten plastic will not substantially enter the gap 48 during molding.
A major portion of the outer surface of the threaded part 30 is defined by the mold cavity 20 and the gate insert 24 . The mold cavity 20 comprises a generally annular body 50 having an inner surface which defines a portion of the outer surface of the part 30 . In the preferred embodiment shown in the drawings, the mold cavity 20 has an inner axial surface 52 which forms an outer circumferential surface 54 of the part 28 . Preferably, the inner axial surface 52 of mold cavity 20 is provided with serrations 56 (not shown) to form corresponding serrations 58 (FIG. 5) on the outer circumferential surface 54 of the part 30 . The mold cavity 20 also has an inner transverse surface 60 defining an outer peripheral surface 62 of the top of part 30 . The central portion 64 of the top of part 30 is defined by a transverse surface 66 of gate insert 24 .
The mold cavity 20 also comprises an annular pinion gear 68 having teeth 70 . Pinion gear 68 is secured to annular body 50 and extends radially outwardly therefrom. The mold cavity 20 comprising annular body 50 and pinion gear 68 is rotatable about the mold axis on bearing surfaces 72 , 74 and 76 .
The apparatus 10 also comprises a mold cavity rotator 78 comprising an axially extending shaft 80 which is mounted in mold cavity plate 14 for rotation parallel to the mold axis. The upper end of shaft 80 is provided with a radially extending drive pinion 82 having teeth 84 which mesh with the teeth 70 of pinion gear 68 . The shaft 80 is provided with teeth 86 below the drive pinion 82 which engage teeth on a rack 88 which is movable transverse to the mold axis. Followers 90 are mounted in the mold cavity plate 14 in order to maintain engagement between the rack 88 and the shaft 80 .
As shown in the drawings, the gate insert 24 has an outer tapered surface 92 which has a truncated conical shape and which tapers inwardly and downwardly toward transverse surface 66 of gate insert 24 . The tapered surface 92 of gate insert 24 forms a seat against a conical inner surface 94 of the mold cavity 14 in the mold closed position shown in FIG. 1 . The gate insert 24 is movable along the mold axis relative to the mold cavity plate 14 , allowing the gate insert 24 to be slightly withdrawn out of engagement with the mold cavity 20 after molding of part 28 and prior to unthreading. For example, the gate insert 24 may be withdrawn by about 0.03 inches. Preferably, the initial separation of gate insert 24 from cavity 20 is produced by disc spring assembly 100 shown in FIGS. 2 to 4 .
The apparatus 10 further comprises a stripper ring 22 which surrounds the core 18 and is mounted in mold stripper plate 16 . After the part has become substantially unthreaded as shown in FIG. 3, the mold core plate 12 and the mold stripper plate 16 are axially moved away from one another, causing the stripper ring 22 to eject the part from the core 18 as shown in FIG. 4 . The stripper ring 22 is preferably provided with at least one air passage 96 through which pressurized air can be passed in order to assist in ejecting the part 30 from core 18 after unthreading has been substantially completed. Air passages are preferably directed upwardly and inwardly so as to direct the pressurized air inside the part 28 . More preferably, a plurality of such air passages 96 are provided. The term “substantially unthreaded” is used herein to indicate that after the unthreading operation a portion of the thread of the part 30 may remain engaged with the thread of the core 18 . Therefore, the apparatus 10 preferably includes stripper ring 22 to ensure that the part 30 will be removed from core 18 .
A preferred method for molding an internally threaded plastic part according to the invention is now described below.
The first step in the method of the invention is to mold part 28 with the mold plates 12 , 14 and 16 in the mold closed position shown in FIG. 1 . In this position, the mold cavity 20 and stripper ring 22 engage one another along line A, and mold plates 12 and 16 engage one another along line B. In addition, gate insert 24 is completely inserted into mold cavity 20 , such that the outer tapered surface 92 of the gate insert 24 is sealed against the inner tapered surface 94 of mold cavity 20 .
After the molding operation has been completed, the gate insert 24 is axially withdrawn slightly from the mold cavity 16 , preferably by about 0.03 inches, such that a space is formed between the outer tapered surface 92 of the gate insert 24 and the inner tapered surface 94 of the mold cavity 20 . At this point, there is preferably no axial movement of mold cavity plate 14 , and therefore the serrations 56 on the mold cavity 20 remain engaged with the serrations 58 on part 30 .
The rack 88 is then moved transverse to the mold axis in order to cause rotation of the shaft 80 in the clockwise direction. Rotation of shaft 80 with drive pinion 82 causes rotation of the mold cavity 20 in a counterclockwise direction.
As the mold cavity 20 is rotated, the mold cavity 20 and mold core 18 become separated to open the mold 28 . Preferably, the rate of separation of the mold cavity 20 and the mold core 18 during unthreading is substantially the same as the rate of axial movement of the part 30 relative to core 18 , thus ensuring continued engagement between mold cavity 20 and part 30 during unthreading. The rate and timing of separating the mold cavity 20 and the mold core 18 relative to rotation of the mold cavity 20 is controlled by any convenient means (not shown), and is preferably controlled by program logic. The gate insert 24 moves with the cavity plate 14 so as to maintain the clearance between the gate insert 24 and the mold cavity 20 during unthreading of part 30 .
After the part 30 becomes substantially unthreaded from core 18 as shown in FIG. 2, the mold cavity 20 and the mold core 18 can be more rapidly separated from one another to the mold open position shown in FIG. 3, the separation being sufficient to allow ejection of the part 30 from core 18 . During separation of the mold cavity 20 and mold core 18 to the mold open position, the mold cavity 20 becomes separated from part 30 , which remains on the core 18 . In order to ensure that the part 30 remains on the core 18 during removal of cavity 16 , a negative pressure is created in the space 98 between the part 30 and the core 18 during separation of the mold cavity 20 and the mold core 18 and and until the mold cavity 20 becomes completely separated from part 30 . The negative pressure is created by vacuum means (not shown) remote from the mold 26 , and is applied to the space 98 between part 30 and core 18 through the air passage 46 and venting gap 48 . Preferably, the negative pressure is applied only during the last portion of the unthreading step and during withdrawal of the mold cavity 20 away from part 30 in order to prevent “dishing” of the top surface of part 30 , which may occur as a result of excessive application of negative pressure to space 98 .
After the apparatus 10 is opened to the mold open position, the unthreaded part 28 is ejected from the core 18 . In order to eject part 28 , the application of vacuum is discontinued and the mold core plate 12 and mold stripper plate 16 are axially separated from one another as shown in FIG. 4, thereby causing stripper ring 22 to push the part 30 from the core 18 . As discussed above, pressurized air is preferably passed through air passages 96 in stripper ring 22 to assist in ejection of part 30 .
Although the invention has been described with reference to certain preferred embodiments, it is not intended to be limited thereto. Rather, the invention includes all embodiments which may fall within the scope of the following claims. | An apparatus for forming threaded molded parts such as closures for containers having improved means for unthreading the formed part from the mold core. The apparatus includes a cavity part and a core part, the cavity part being rotatable relative to the core part, such that simultaneous rotation of the cavity and opening of the mold results in unthreading of the part from the core. The mold cavity is rotationally coupled to a mold cavity rotator which is preferably driven by means of a rack. The rotation of the mold cavity is timed with the mold opening step such that the threaded part is unthreaded from the core as the mold plates are separated. | 8 |
This is a division of application Ser. No. 08/296,939, filed Aug. 29, 1994, now U.S. Pat. No. 5,399,633 which in turn is a continuation of application Ser. No. 08/026,165, filed Mar. 1, 1993 (abandoned), which in turn is a continuation of application Ser. No. 07/798,176, filed Nov. 26, 1991 (abandoned), which in turn is a continuation of application Ser. No. 07/450,466, filed Dec. 14, 1989 (abandoned).
BACKGROUND OF THE INVENTION
(1) Field of the Invention
The present invention is directed to reduction in the emission of highly toxic volatile products, such as methyl bromides or iodides or ethylbromides or iodides, during the cure of fluoroelastomers with peroxides.
(2) Description of the Related Art
The cure with organic peroxides of the fluoroelastomers containing, as cure sites, bromine or iodine atoms along the polymeric chain and/or at the end of same is well known. In said fluoroelastomers, bromine or iodine are introduced into the elastomeric macromolecule by using, in the polymerization step, brominated or iodidated comonomers such as in particular fluorobrominated olefins, brominated or iodidated fluorovinyl ethers, or by using in the polymerization brominated or iodidated compounds such as chain transferors.
In the peroxide cure, use is generally made of organic peroxides of the aliphatic or cycloaliphatic type, or saturated or unsaturated alkylaromatics, such as for example:
2,5-dimethyl-2,5-di(ter.butylperoxy)hexene-3
2,5-dimethyl-2,5-di(ter.butylperoxy)hexane
dicumylperoxide
ter.butylperbenzoate
ethyl-3,3-di(ter.butylperoxy)butyrate
1,1-bis(ter.butylperoxy)3,3,5-trimethylcyclohexane
which give rise, in the cure process, to the formation of methyl or ethyl radicals. These radicals, when combining with the bromine or iodine contained in the fluoroelastomer, can give rise to the above-mentioned methyl or ethyl bromides or iodides, which are highly toxic and probably also cancerogenous volatile products.
Therefore, while the cured articles produced by means of peroxide cure of fluoroelastomers containing bromine or iodine exhibit excellent properties and characteristics at least partially higher than those of the fluoroelastomers cured by means of iones, the peroxide cure of the abovesaid products involves a serious hazard for the health of the operators and espress prohibition of such processing in the next future from the competent authorities is considered as possible.
SUMMARY OF THE INVENTION
Thus, it is an object of the present invention to obviate the above-mentioned serious drawback by adding to the cure mix a substance capable of substantially reducing the emission of methyl or ethyl bromides or iodides during the cure.
In fact, it has surprisingly been found that certain substance types introduced into the mix in a moderate amount, generally ranging from 0.1 to 3 parts by weight for 100 parts by weight of fluoroelastomer, are capable of substantially reducing the emission of said toxic products without sensibly altering the cure trend or the characteristics of the resulting vulcanizate. The action mechanism of the additives according to the present invention is probably based on the fact that they are capable of combining with the methyl or ethyl radicals deriving from the organic peroxide, thereby forming new radicals capable of continuing the cross-linking reaction, so preventing any formation of methyl or ethyl bromides or iodides. However, on the basis of such assumption it is not possible to foresee which substances are actually suited as additives according to the invention: in fact, many substances which are surely capable of blocking the methyl and ethyl radicals and which drastically reduce the emission of the abovesaid bromides and iodides, negatively interfere with the cure process, causing it to become extremely slow and inefficacious and giving rise to vulcanizates of very bad quality.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The products suited as additives according to the present invention are the ones belonging to the following classes:
a) Benzothiazole and derivatives thereof of general formula: ##STR1## wherein: X represents H, --SH, ##STR2## in particular benzothiazole, 2-mercaptobenzothiazole, benzothiazole disulphide, morpholin-2-benzothiazole sulphenamide, zincmercapto-benzothiazole.
b) Maleamide derivatives of general formula: ##STR3## wherein A=H, or together with T forms a bond, T represents --OH, ##STR4## or together with A forms a bond; R represents H, alkyl with 1 to 6C, halogen, --NO 2 and when T forms a bond together A, R may be also ##STR5## c) Thiurams derivatives of general formula: ##STR6## wherein Y represents ##STR7## R' represents alkyl with 1 to 4C, in particular tetraalkylthiuram disulphide, zincdiethyldithiocarbamate.
d) Diphenylguanidine derivatives of general formula: ##STR8## wherein R 2 represents H, alkyl with 1 to 6C, in particular the compounds wherein R 2 represents H or CH 3 . Moreover other compounds such as maleic anhydride, diaryl-formamidines and the derivatives of diazo- and triazo-dicyclodecenes are resulted to be suited as additives.
The additives according to the present invention, when used in amounts generally ranging from 0.1 to 3 parts by weight for 100 parts by weight of elastomer (p.h.r.) and in particular from 0.2 to 2 p.h.r., beside sensibly reducing the emission of the toxic products methyl or ethyl bromide or iodide, in some cases also by 90%, impart to the curable composition the following characteristics:
increase of the time which is necessary for the scorching to occur (scorching time) and, by consequence, a higher processing safety;
decrease of the Mooney viscosity of the mix and therefore an improved processability;
moderate influence on the cross-linking rate and yield at 180° C.
All the additives indicated hereinbefore can be prepared according to known methods described in the technical literature.
The fluoroelastomers, to which the present invention is applicable, are all those which contain bromine or iodine atoms ascure sites.
Among the most known, the following are to be cited: copolymers of CH 2 =CF 2 with CF 3 -CF=CF 2 and optionally also with C 2 F 4 with perfluorovinylethers, containing little amounts of bromine or iodine which are introduced by copolymerizing a little amount of brominated or iodidated monomer such as brominated olefins, perfluorobromoalkylperfluorovinylethers, or also by using chain transferors consisting of bromo- or iodo-alkyl compounds.
The mixes based on fluoroelastomers curable with peroxides, which can be additioned according to the present invention comprise, beside the organic peroxide, conventional ingredients such as carbon black and other reinforcing fillers, peroxide curing co-agents (for example triallyl isocyanurate), metal oxides or hydroxides (for example PbO, ZnO), and processing aids.
The following examples are given merely to illustrate but not to limit the present invention.
The evaluation of the CH 3 Br emission under curing conditions was generally carried out according to the following method:
MODALITIES FOR DOSING THE CH 3 BR EMISSION
20 g of a finely particled mix (polymer+fillers) are treated at 180° C. in a closed reactor, for 30 minutes at a pressure of 0.5 kg/cm 2 abs. in a nitrogen atmosphere.
Then the mix is cooled to 40°-50° C. and, as an interior standard, 1 cc of A114 (C 2 Cl 2 F 4 , b.p.=4° C.) is added.
The gas phase is mixed and subjected to gaschromatographic analysis.
______________________________________Column: POROPAK Q______________________________________T = 100° C.______________________________________
In example 2, conversely, the actual emission occurring under practical curing conditions at 170° C. is determined by determining the CH 3 Br in air samples withdrawn above the mold.
Utilized elascomer:
P.1 terpolymer of CH 2 =CF 2 66.2% by moles, C 3 F 6 18.2%, C 2 F 4 15.2%, containing bromoperfluoroethylvinylether in an amount equal to 0.65% by weight of bromine.
P.2 terpolymer of CH 2 =CF 2 54.1% by moles, C 3 F 6 22.2%, C 2 F 4 22.9%, containing bromoperfluoroethylvinylether in an amount equal to 0.54% by weight of bromine.
The ingredients of the mixes, besides the additive according to the invention, are, in parts by weight for 100 parts by weight of terpolymer, the following:
2,5-dimethyl-2,5-di-ter.butyl-peroxy-hexane at 45% on inert filler (Luperco 101XL), 3 parts;
triallyl isocyanurate (TAIC) at 75% on inert filler, 4 parts;
PbO, 3 parts;
carbon black MT, 30 parts.
The evaluation of the cure trend is carried out by determining the Δ torque (MH-ML) by means of an ODR oscillating disc rheometer (Monsanto type) according to standard ASTM D 2084/81.
Measuring is effected at 180° C., the maximum torque MH is determined after 12 minutes, by "arc 3".
EXAMPLE 1
The tests were carried out using terpolymer P.1.
The elastomer without the additive of the invention provided during curing a Δ torque equal to 71.
In some tests, the low reduction of the CH 3 Br emission was due to the insufficient amount of additive: by increasing said amount within the above-cited range, it is possible to improve the effect (see for example tests 7 and 8).
Test 21 is a comparison test and represents the case of products which drastically reduce the CH 3 Br emission, but at the same time they prevent or strongly reduce the cure.
TABLE 1__________________________________________________________________________ Δ TORQUE % REDUCTIONTEST PHR MH-ML OF CH.sub.3 BrNo. ADDITIVE ADDITIVE (STANDARD = 71) EMISSION__________________________________________________________________________ 1##STR9## 1.65 60 72% 2##STR10## 0.5 65 26% 3##STR11## 1.60 70 17% 4##STR12## 1.80 68 34% 5##STR13## 0.5 71 31% 6##STR14## 1.92 72 31% 7##STR15## 1.15 64 35% 8##STR16## 0.77 66 17% 9##STR17## 1.68 51 77%10##STR18## 0.9 59 57%11##STR19## 1.0 60 51%12##STR20## 1.8 52 84%13##STR21## 1.2 51 86%14##STR22## 0.5 65 28%15##STR23## 0.5 70 70-80% MBT16##STR24## 0.5 71 70-90%17##STR25## 0.5 68 90% tetraetrithiuramdisulphide18##STR26## 0.5 67 87% zincodiethyldithio- carbamate19##STR27## 0.5 72 61% (ZMBT) Zn mercaptobenzothiazole20##STR28## 0.5 80 79% MBS Morpholine 2-benzothia- zole sulphenamide FOR COMPARISON21##STR29## 0.6 8 90% Benzoquinone dioxime__________________________________________________________________________
EXAMPLE 2
Test were carried out in order to check the correspondence between the CH 3 Br reduction determined by means of the laboratory test described for example 1 and the actual reduction achieved in the curing process in mold at 170° C. under actual conditions, determined by analysis of an air sample withdrawn above the molded article immediately after having drawn the vulcanizate from the mold. The additive utilized was mercaptobenzothiazole disulphide (MBTS); a test was carried out without the additive in order to have a comparison of the values of the Δ torque and of the CH 3 Br emission.
The elastomer utilized was of the type P.2 described hereinbefore.
The results are the average of analytical determinations on 5 air drawings.
TABLE 2______________________________________ PERCENT REDUC- PERCENT Δ TION OF CH.sub.3 Br REDUCTION OFADDI- MM- EMISSION LAB- CH.sub.3 Br EMISSIONTIVE PHR ML ORATORY TESTS MOLDING TESTS______________________________________-- -- 62 -- --MBTS 0.25 64 79% 62%MBTS 0.5 66 85% 98%______________________________________
EXAMPLE 3
Characterization of the curable mixes and of the vulcanized product.
The characteristics compared with those of the nonadditivated products are reported in the following tables.
In particular, from table 3 it is apparent that the mixes containing the additive according to the invention exhibit a remarkably higher scorching timen, a decrease of the Mooney scorch viscosity (at 135° C.) and a decrease of the Mooney viscosity at 121° C.; these characteristics are indicative of a better processability of the mix.
Table 4 contains some characteristic values which provide idications about the cure trend.
The characteristics of the cured material are reported in Table 5.
TABLE 3__________________________________________________________________________COMPOSITION OF THE MIX (ASTM D. 3182-82) ASTM D. 164E-82PARTS BY WEIGHT FOR 100 PARTS 135° C.BY WEIGHT OF POLYMER 121° C. MOONEY additive carbon MOONEY SCORCHMix No.polymer (p. by wg.) luperco TAIC PbO black MT ML (1' + 10') MV t 15__________________________________________________________________________1 P.1 -- 3 4 3 30 86 42 11' 42"2 P.1 MPM (1.5) 3 4 3 30 84 40 24' 18"3 P.1 MBT (0.5) 3 4 3 30 74 35 61' 00"4 P.1 MBTS (0.5) 3 4 3 30 79 35 60' .sup.5 P.2 -- 3 4 3 30 110 49 13' 18"6 P.2 MBTS (0.25) 3 4 3 30 102 45 26' 24"7 P.2 MBTS (0.5) 3 4 3 30 101 43 33' 42"__________________________________________________________________________ ##STR30## ##STR31## ##STR32##
TABLE 4__________________________________________________________________________CURING CHARACTERISTICSASTM 02084-8, - ODR, 180° C.; arc ± 3 Mix No. MI MH ts 2 t'50 t'90 V maxPOLYMER (from tab. 3) (lbf · in) (lbf · in) (s) (s) (s) (lbf · in/s) MH-ML__________________________________________________________________________P.1 1 23 82 69 117 243 0.75 59P.1 2 20 95 75 129 312 1.01 75P.1 3 16 77 129 219 348 0.41 61P.1 4 16 81 135 195 303 0.7 65P.2 5 24 86 69 126 360 0.63 62P.2 6 19 83 90 144 324 0.73 64P.2 7 17 83 99 153 330 0.80 66__________________________________________________________________________
TABLE 5__________________________________________________________________________ MECHANICAL PROPERTIES after post-cure (250° C. + 24 h) after press-cure (170° C. + 10') ASTM ASTM ASTM D.2240-8 ASTM D.624-81 D2240-81 D1414-78Mix ASTM D.412-83 Hardness Tear-Strength ASTM D.412-83 Hardness (*) C.S.No. Tensile propert. (points) 170° C. Tensile properties (points) (%)POLY- (from (MPa) (MPa) (MPa) (%) H- (N//mm) (J//m) (MPa) (MPa) (MPa) (%) H- O-RMER tab. 3) M100 M200 T.S. E.B. Shore A F/s E/s M100 M200 T.S. E.B. Shore 214__________________________________________________________________________P.1 1 4.3 9.9 10.8 234 70 3.3 11.5 5.9 14.7 15.2 189 73 30P.1 2 3.5 10.1 12.6 240 70 3.6 12.4 5.4 16.8 18.4 214 73 33P.1 3 2 5 8 349 67 3.4 14.2 4.6 13.2 14.9 219 74 44P.1 4 2.9 8.7 10.8 268 68 3.6 13.2 5.0 14.5 16.1 216 74 42P.2 5 3.7 8.3 11 306 73 4.9 28.1 5.5 15.8 18.5 227 74 33P.2 6 3.6 7.9 10.6 338 72 4.6 24 5.9 16.1 19.5 234 76 35P.2 7 3.7 8.1 10.9 319 72 4.3 22.2 5.9 16 19 230 76 34__________________________________________________________________________ (*) C.S. = compression set at 200° C. for 70 h.
EXAMPLE 4
The tests reported in Table 6 show that the reduction of the CH 3 Br emission and the cure trend vary on variation of the utilized polymer type and of the bromine content.
In all the tests reported in Table 6 the utilized additive was phenylmaleinimide: ##STR33##
Other components of the mix were:
______________________________________Luperco 3 p.h.r.TAIC 4 p.h.r.PbO 3 p.h.r.carbon black 30 p.h.r.______________________________________
TABLE 6______________________________________ Δ % REDUCTION ADDITIVE TORQUE OF CH.sub.3 BrPOLYMER P.H.R. MM-ML EMITTED______________________________________P.1 -- 71 --P.1 1.5 76 15%P.41 -- 62 --P.41 1.5 55 29%P.2 + P.41 (+) -- 65 --mixP.2 + P.41 (+) 1.5 64 37%mix______________________________________
Polymer P.41 contains:
CH 2 =CF 2 53,4%; C 2 F 4 23,9%; C 3 F 6 22,7%, and bromovinylether in an amount equal to 0.93% of Br.
(+) Bromine content of the polymeric mix: Br=0.72%. | The emission of the highly toxic volatile products, such as methyl bromides or iodides, or ethyl bromides or iodides, during the cure with peroxides of fluoroelastomers containing bromine or iodine atoms is substantially reduced by adding to the cure mix small amounts of substances capable of combining with the radicals which give rise to the aforesaid toxic products, thereby preventing them from forming. This procedure does not sensibly affect the cure trend and results. | 2 |
BACKGROUND OF THE INVENTION
This invention relates to a borehole tool, and, more particularly, to a method and apparatus for performing the downhole operation of injecting a fluid into the wall of a wellbore through a perforation made by the tool. The present invention has been developed in response to a particular problem involving a squeeze cementing operation in large diameter wellbores. Therefore, while the methods and apparatus disclosed herein would lend themselves to any operation involving injection of a fluid into the formation, the disclosure for the most part, and particularly the background of the invention, will relate to a squeeze cementing operation.
Oil and gas well cementing is a process of mixing a cement-water slurry and pumping it down through steel casing to critical points located in the annulus around the casing. Cementing a well helps provide protection against salt water flow for possible productive zones behind the casing, thus conserving the producing formation's value. Also the cement helps provide protection against corrosion of the borehole casing from subsurface mineral waters and electrolysis from the outside. In addition, cementing reduces the danger of the fresh water strata being contaminated by oil and gas or salt water flow. It also reduces the danger of a blow out caused by high pressure gas zones behind a casing and from collapsing casing caused by tremendous external pressures inherently encountered. Cementing operations for protection against the above-described downhole conditions are called primary cementing. Another type of cementing operation effected during an oil or gas well's life is secondary cementing. Secondary cementing deals with the completion and remedial repairs on a well after the producing zone is reached.
Squeeze cementing is the most common type of remedial (secondary) cementing. The process includes the utilization of hydraulic pressure to force, or squeeze, a cement slurry into contact with a formation, either in open hole or through perforations in the casing or liner. A wide selection of various types of prepared oilwell cements exists in the prior art. Adjustable water-cement ratios and various admixes provide a very flexible process for solving many problems of a corrective or remedial nature in producing oil or gas wells. pg,3
In many conditions the cement slurry may be applied to water or oil or gas bearing portions of a producing zone to eliminate excessive water or gas without sealing off the oil. This process is especially beneficial in correcting defects in producing wells. For example, where there is a problem of high gas/oil ratios, squeeze cementing can be used where an oil zone can be isolated from an adjacent gas zone, so that the gas/oil ratio can usually be improved to help increase oil production. Another example of its use is in the production of excessive water. In this case water sands can be squeezed off below the oil sand to help improve water/oil ratios. Additionally, independent water zones can usually be squeezed to eliminate water intrusion into a wellbore.
Numerous other prior art uses for squeeze cementing exist. A casing leak may be repaired by squeezing cement through the damage area. Low pressure zones that imbibe oil, gas, or drilling fluids can usually be sealed by squeeze cementing. Channeling or insufficient annular fillup behind the casing can usually be overcome by squeeze cementing. Greater protection against fluid migration into the producing zone is often possible by perforating below, squeezing perforations, repeating the process above the zone, drilling out and then perforating for production. In wells having a multiple producing zone potential, it is a common practice to isolate a zone for production and produce it to depletion. After squeezing the depleted zone, the remaining zones are, in turn, perforated, produced, depleted and plugged. In addition squeeze cementing is sometimes employed to seal off perforations or plug a depleted open hole producing zone. This helps prevent fluid migration to and from the abandoned zone.
Two prior art methods of squeeze cementing that will be described are the brandenhead method and packer method. In the bradenhead method, cement is pumped into the cased hole through tubing or drill pipe, displacing well fluids into the annulus. After the cement is placed across the zone to be squeezed, the tubing is pulled above the perforations and the annulus is closed at the surface. As pumping of cement continues, the cement moves into the zone. Circulation of the annulus is limited by the closed hydraulic system. After the cement is displaced, the slurry remaining in the casing can sometimes be reversed out. Usually however drilling is required to remove the cement. Since no packer is used, only low pressure squeezes are permitted because of casing limitations. Pinpoint accuracy of spotting the cement across the interval to be squeezed is then difficult to obtain because no packers are used.
The packer method is generally considered to be superior to the bradenhead method. The interval to be squeezed is isolated from the surface by a packer run and set on tubing. Many types of packers are conventionally available, each designed for specific well conditions, and either retrievable or permanent packers can be used. In certain instances it is necessary to isolate the section below the perforations to be squeezed. A bridge plug is placed below the perforations for this purpose. The upper perforations are then squeezed and the remaining slurry reverses out.
The packer method permits high squeeze pressures and permits more efficient placement of the slurry. However, the packer method involves the use of commercially available packers which are normally available only up to a casing size of 13 and 3/8ths inches. Problems thus arise in boreholes of larger diameters. Additionally, the packer operation is typically complex due to setting bridge plugs below perforations and the packers above. Finally, when using a squeeze packer, it is of critical importance to pressure-test the squeeze area including the packer seal and tubing and casing leaks. Even small leaks in the system can cause rapid local dehydration of the slurry and a false indication of the squeeze progression. It may thus be seen that for larger diameter casings (on the order of 36 inches) seal integrity around the squeeze is of tantamount import and prior art methods and apparatus have proven inadequate.
It would be an advantage thereof to provide a method and apparatus for squeeze cementing boreholes of relatively large diameter which could overcome the problems of the prior art. The method and apparatus of the present invention provides such a system. A downhole device is provided for utilization in any size wellbore wherein select penetration of the wellbore casing must be effected. Delivery of the slurry is herein effected through narrow conduit in closed communication with the downhole device which sealably engages the casing about the point of penetration. In this manner casing packers may be eliminated and post squeezing redrill of plugs obviated.
SUMMARY OF THE INVENTION
With these and other objects in view the present invention relates to the concept of a fluid injections and perforation system including a downhole tool, suspended in a wellbore by length of conduit and incorporating a selectively operable hold down mechanism which fixedly positions the tool in the wellbore in a selected location and moves a perforating and injection portion of the tool into solid contact with the wall of the wellbore whereupon the wellbore is penetrated to permit fluids to be pumped innto the penetration. Means are provided to selectively release the device from its fixed position for retrieval to the surface.
In another aspect, the invention includes a downhole tool constructed for angular connection to suspension conduit and the injecting of fluid carried by the conduit into the side wall of a wellbore. The tool comprises a housing having a central hub unit and a lateral body portion adapted for secured positioning within the wellbore. The lateral body includes a piston retractably mounted therein for extending outwardly thereof in abutting engagement with the side wall of the wellbore. The lateral body also includes a perforation barrel for discharging into the side wall of the wellbore and causing penetration thereof. Means are provided for selectively activating the piston to secure the tool within the wellbore and for selectively activating the perforation barrel for causing penetration. The lateral body is also formed with a passage therein in closed communication with the suspension conduit and a penetration made by the perforation barrel. In this manner fluid such as cement may be passed via the conduit into the penetration.
In yet another aspect, the invention includes a method of injecting fluid such as cement into a downhole side wall of a wellbore. A downhole tool is provided having an extendible arm section for securely wedging the tool in the wellbore. The tool is then suspended in the wellbore on a string of conduit and secured in its downhole position. A penetration member in the tool is activated to penetrate the wall of the adjacent wellbore casing. Fluid, such as cement, may then be passed through the conduit into the penetration. The tool can then be released from the wellbore by retracting the extendible arm and therein withdrawn. In this manner squeeze cementing may be effected without the use of packers and expensive redrilling operations.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic illustration of one embodiment of a well tool constructed in accordance with the principles of the present invention shown positioned in a cased borehole and illustrating the method of use thereof;
FIG. 2 is an enlarged, cross-sectional elevational view of a wall engaging portion of the well tool shown in FIG. 1;
FIG. 3 is an enlarged, cross-sectional view of a portion of the tool taken along the lines 3--3 of FIG. 2;
FIGS. 4 and 5 are alternative embodiments of wall engaging portions of the tool shown in FIG. 2; and
FIGS. 6, 7, 8 and 9 are schematic illustrations of the portions of the particular embodiment of the tool shown in FIG. 2 performing a downhole operation.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to the drawings, there is shown in FIG. 1 one embodiment of a well tool structure suspended by means of a pipe string 10, with the structure including a bent offset sub 11, a shoot and squeeze tool 12 and a depending centralizer 13 patched to a threaded bottom portion of the tool 12 and depending downwardly therefrom. The centralizer 13 includes a longitudinal body portion 17 having threaded body portion 19 at its upper end for reception within the lower, mating end of the tool 12. The centralizer also includes a threaded sleeve 14 threadably engaging the upper end of the body 19, a floating collar 18 positioned about the body 17 and arranged to slidingly move thereover in an up and down direction. A spring 16 is positioned between the sleeve 14 and the collar 18 for maintaining a spring bias against the collar, which in turn is connected to lever arms 21 for supporting rollers 22. A linkage 23 connects a bottom bullnose 24 with the rollers 22. It is readily seen that the compression spring 16 provides a force downwardly on the floating collar 18 to move the rollers 22 outwardly into a wall engaging position with the inner wall of a casing 26. As shown in FIG. 1, the casing 26 is positioned through a formation 27 with the centralizer 13 in position for centering the shoot and squeeze tool 12 therein. In this position the tool 12 is ready for operation.
For a more detailed description of the tool 12 reference is made to FIG. 2 of the drawings. The tool 12 includes a lateral body portion comprising a wall engaging ortion 28 and a shoot and squeeze portion 29 shown extending from opposite sides of the central hub, or tool body 31. The longitudinally extending portion of the tool body 31 has a box threaded end 32 at its upper end for receiving a mating end of a section of tubing, or as shown in FIG. 1, for receiving a mating portion of the bent sub 11. A passage 33 is therein formed centrally through the base of end 32 of body 31 for communicating the box end 32 with the interior of the lateral tool portions.
The lateral body portion of the tool 12 is adapted for wedging the tool in the wellbore and injecting a fluid such as cement into a penetration formed therein. The shoot and squeeze assembly 29 of the tool 12 may thus be seen to be comprised of an outer barrel 34 which is threadably received within the main body 31. A pair of annular collars, including inner collar 36 and outer collar 37, are threadably engaged with one another and with the barrel 34 to provide an annular space between said collars for receiving a rubber sealing member 38 therebetween. An inner or discharge barrel 39 has a central bore 41 and a plurality of ports 42 communicating its inner and outer walls near the outer end of the barrel, with the outer end of the barrel being formed in a taper to provide a sharp edge endsurface 43. A seal 44 is positioned between the outer surface of the barrel 39 and the collar 36. In this configuration a sealed fluid channel is provided in an annular space 46 formed between the outer barrel 34 and inner barrel 39, with this channel connecting with the ports 42 to the interior bore 41 of the inner barrel 39. Covering the end of the barrel 39 is a brass cap 47 being press fitted into a groove formed in the interior bore 41. At the other end of the bore 41 a case hardened steel projectile 48 is shown received within the end of the barrel. A brass gas check 49 is preferably positioned behind the projectile and separates the projectile from a black powder charge 50. A detonating fuse 51 is positioned within the powder charge and is connected to a detonating circuit operable from the surface by means of wires 52 extending through the body of the tool 12.
Still referring to FIG. 2, the wall engaging portion 28 of the tool 12 is shown extending outwardly from body 31 on the opposite side from the shoot and squeeze portion 29. The wall engaging portion 28 includes an expandable arm comprising an outer housing 56 which is threadably received within the tool body 31 to form a cylinder 57 therein. A setting piston 58 is slidably received within the housing 56 for reciprocal movement therein, and has an enlarged base portion 59 at its inner end for sealingly engaging the inner walls of the cylinder 57 circumferentially therewithin. The piston 58 has a hollow central, inner portion 61 for receiving a slow burning powder charge 62. An igniter 63 is provided for activating the powder 62 and is connected by means of wire 64 to an igniter circuit extending to the surface. A check valve 66 is shown positioned on the outside of the housing 56 and provides a means of communicating a select fluid to the cylinder 57. The outer end of the cylinder is enclosed by an endcap 67. A wall engaging pad 68 is shown attached to the outer end of the piston 58. The wall engaging pad 68 is constructed of a steel plate or ring having an outer surface configuration of an approximate radius, using angles, to facilitate centralization of the tool within the circular cross-sectional configuration of the wellbore.
Referring now to FIG. 3 of the drawings a pair of pressure dump screws 71 and 72 are shown threadably received within the housing 56 into passages providing a sealed fluid communication path between the interior bore 61 of the piston 58 to the exterior of the tool housing 56. These pressure dump screws preferably contain detonating fuses which are connected by means of electrical wires to the surface. Activation of the detonating fuse opens the fluid communication path between the exterior wall of the housing 56 and the interior bore 61 of the piston 58 whereby venting may be facilitated.
In the operation of the apparatus thus far described, reference may be made to FIGS. 1 and 2 as well as FIGS. 6, 7, 8 and 9. In order to introduce a fluid into the formation 27 behind the casing 26 the tool thus far described is lowered on a string of tubing 10 into the wellbore to a location where it is desired to operate the tool. Upon reaching this position, an electrical circuit is operated at the surface which connects with the wire 64 and in turn actuates the igniter 63 to ignite the slow burning powder positioned within the interior of the piston 58. Upon burning of the powder a gas is formed which expands within the chamber 61 to move the piston 58 outwardly from the tool 12 and against the sidewall of the casing 26.
Extension of the piston 58 wedges the tool 12 securely within the wellbore and therefore the piston must be retracted before the tool 12 may be removed therefrom. Prior to the running in of the tool 12 into the wellbore a compressible gas is therefore passed through the check valve 66 into the cylinder 57. As the piston 58 is moved outwardly by the expansion of the gas from the powder 62 within the interior of the piston, the existing gas within the cylinders is compressed. Upon the extended movement of the piston 58 the wall engaging pad 68 abuttingly engages the inner surface of the casing 26, thus moving or shifting the body 31 of the tool 12 in an opposite direction and moving the shoot and squeeze portion of the tool into abutting engagement with the opposite side wall of the casing. This step is clearly illustrated in FIGS. 6 and 7 wherein the centerline of the tool 12 may be seen to shift.
In the next step in the operating sequence of the tool 12, a monitored fluid pressure is placed on the interior of the tubing or pipe string 10 communicating the fluid pressure with the channel 46, ports 42 and thus with the interior bore 41 of the inner barrel as it is held against the inner wall of the casing 26. In this manner the system is checked for leaks and the seal integrity confirmed. It may be seen that the sharpened edge portion 43 on the outer end of the barrel is configured and constructed for being forced into the wall of the tubing in a mating engagement therewith to effect a seal thereupon. In addition the rubber member 38 comprising a donut shaped seal around the barrel 39 is compressed as the tool 12 is expanded into the casing wall 26 to also provide a sealing surface. If these sealing members fail to hold the aforesaid monitored pressure, the tool 12 may be removed.
It is readily seen that when the actuating portion of the tool 12 including the wall engaging pad 68 of the piston 58 moves or shifts the tool 12 within the borehole, the tool 12 is caused to move offcenter in a pendulous fashion thus tipping the barrel 39 into a slightly nonhorizontal position. In such an offcenter configuration the sharpened pointed edge 43 would normally not strike the inner wall of the casing 26 at a ninety degree angle to effect a perfect seal. In order to compensate for this angular offset the bent sub 11 is preferably included in the tool string. The exact angle α of the bent sub 11 depends on the diameter of the casing 26 and the length of pipe string 10 thereabove and is readily calculable as a trigonometric function thereof. The bent sub 11 provides the offset angle to the position of the tool 12 as it hangs in the wellbore so that in the operating position of the tool 12 as shown in FIG. 7, the barrel 39 is caused to abut the inner wall of the casing 26 at a right angle therein permitting an effective seal between the sharpened edge 43 and the inner wall of the casing 26. If a proper seal has been effected, the monitored check pressure can be applied to the interior of the string 10 communicating with the interior of the barrel 41 and no pressure drop can be detected.
Once the tool 12 is secured within the wellbore and the seal has been confirmed, an electrical circuit connecting the wires 52 of the projectile 48 is activated to operate the detonating fuse 51 and in turn ignite black powder charge 50. As shown in FIG. 7, ignition of the charge and the resulting expansion moves the brass gas check seal 49 outwardly against the projectile 48 thus propelling the projectile down the barrel 41, knocking out the cap 47, penetrating the wall of the casing 26, and moving outwardly into the formation 27. This discharge effects penetration and opens the path for fluid communication from the passage 46 therewith. It should be understood that other perforation techniques are contemplated herein and the use of the projectile 48 is but one embodiment. For example, penetration may be effected by the utilization of a jet, produced by the ignition of a suitably shaped powder charge of the type conventionally used for simple casing perforation in smaller downhole applications.
Referring now to FIG. 8 of the drawings, it may be seen that a cement slurry or other fluid is pumped from the surface through the tubing string 10 into the tool 12 through the channel 46 and ports 42 and outwardly through the end of barrel 41 into the penetration area formed by the projectile 48 in the casing 26 and thence into the desired formation behind the casing. When the cementing or other fluid injection operation is ended, and sufficient setting up time has been allowed electrical circuits are actuated first to the dump screws 71 and 72 which communicate the exterior of the housing 56 with the chamber 61 within the wall engaging portion of the tool to release pressure behind the piston 58. In this manner the previously compressed fluid within the cylinder 57 provides sufficient force upon expansion to move the enlarged portion 59 of the piston to the left and disengage the pad 68 from the casing wall 26. This retraction step permits the tool to return to the center of the wellbore as shown in FIG. 9 for retrieval to the surface, after the cement around the end of the barrel 39 has been broken. It may be seen that the area of the cement to be broken is relatively small and limited to the inside diameter of the barrel 39. For this reason, relatively small forces are required to free the tool 12 from the adjacent cemented penetration.
Having thus far described the method and apparatus of one particular embodiment of the tool 12, various alternate embodiments, still within the spirit and scope of the present invention, will be discussed. Referring now to FIG. 4, there is shown the wall engaging portion 28 of the tool 12 including a spring 80 longitudinally disposed within the cylinder 57 of the housing 56. The spring 80 is a compression spring which functionally replaces the aforesaid gas placed within the cylinder 57 prior to use of the tool 12. The use of nitrogen as the subject gas has been found satisfactory in the above described application. However, the effectiveness of the gas depends upon its compression by the piston 58 and the integrity of the seals therearound. In order to eliminate this one area of seal criticality, the spring 80 may be utilized, since it requires no seal. The spring 80 is simply compressed during the extension of the piston 58 and, once the expansion pressure is vented through screws 71 and 72, the spring 80 expands and retracts the piston. Since no cylinder gas is required, the pressure of check valve 66 may be seen to have been eliminated in this embodiment.
Referring now to FIG. 5, there is shown the wall engaging portion 28 of the tool 12 including hydraulic lines in communication with the cylinder 57 of housing 56. The utilization of an hydraulic system functionally replaces the powder charge 62, igniter 63, ignition wire 64, and check valve 66. A first hydraulic line 82 formed of flexible steel pipe, or the like, is sealably connected to the housing 56 through a fitting 84 threadably secured therein. Hydraulic fluid is thus communicated to the hollow, central inner portion 61 of the piston 58 for forcing the piston outwardly. A second hydraulic line 86 is sealably connected to the housing 56 through a fitting 88 threadably secured therein. Hydraulic fluid is similarly communicated to the cylinder 57 around the piston 58 for forcing the piston inwardly. In operation, fluid is pumped from the surface through line 82 to wedge the tool 12 in the wellbore at a select time. Fluid is thus received into line 86 from the cylinder 57 as the piston 58 is extended. Retrieval of the tool 12 is effected by the reverse process. The advantage of such a system is positive control of the position integrity of the tool 12. Since hydraulic pressures are monitored at the surface the expansion force of the piston 58 can be checked. The use of powder charge 62, although totally effective does not provide the surface to downhole control and monitoring parameters. Moreover, for prolonged squeeze cementing operations the hot, expanded gas produced by the burning of powder 62 can cool and reduce the expansion pressure to some degree. With the hydraulic system herein set forth and described such considerations are obviated.
The utilization of a pressure fluid such as the hydraulic system described also provides the following alternative embodiments which are not particularly set forth and shown in the figures. An hydraulic line 82 may be provided to expand the piston 58 through the housing 56 in order to seat the tool 12. In place of a return line 86, either the gas or the spring embodiments shown in FIGS. 2 and 4, respectively, may be utilized. In this manner, a positive expansion control may be effected for wedging and seating the tool 12 in the wellbore, while the simpler gas or the spring elements are utilized to retract the piston 58. It may also be seen that a positive expansion may be effected utilizing the pipe string 10 to carry pressure fluid, such as gas, to the cavity 61 behind the piston 58. Flow passages, not shown, may be constructed in the body 31 to responsively segregate the function of the pipe string 10 from one of pressurizing the piston cavity 61, to one of communicating with the annulus 46. For example, the body 31 may be provided with a rotatable valve element, responsive to the pipe string rotational position and/or a ball dropped down the pipe string 10 from the surface. The valve element may be set in communication with the cavity 61 upon the lowering of the tool into the borehole, wherein the tool may be wedged and securely held therein by the piston 58. With the tool 12 securely held, the pipe string may be rotated relative thereto, sealing off the cavity 61 and opening communication with the annulus 46, through which fluid injection is to be effected. After the injection operation is completed, the pipe string 10 may be rotated back to vent the seating pressure from the cavity 61. The compressed spring or gas retraction construction above described may be utilized to then return the piston 58 to its retrieval position. Similarly, the pressure dump screws 71 and 72 may be utilized to vent the pressure in cavity 61 rather than rotating the pipe string 10 in this particular alternative embodiment.
The methods and apparatus herein described also provide numerous functional advantages. With the tool 12, there is no need for a conventional large diameter packer to squeeze under, which would require extremely large hold-down anchors and elaborate back flow to wash out the excess cement after squeezing. For example, some cement will be left in the tool 12 and lower part of the pipe string 10 after squeezing. It may be preferable to wash out this excess downhole simply for tool maintenance. Such an operation is easily facilitated by pumping fluid down the casing 26 after the tool 12 is unseated. If the unseating occurs before the cement is completely set, the fluid will flow into the end of the barrel 39, through the ports 47 and the annulus 46 and up the pipe string 10 to clear the passage of cement.
It is believed that the operation and construction of the above described invention will be apparent from the foregoing description. While the method of and apparatus for squeeze cementing in boreholes shown and described has been characterized as being preferred, it will be obvious that various other changes and modifications may be made therein without departing from the spirit and scope of the invention as defined in the following claims. | A well tool system including a device for downhole suspension by means of conduit for engaging and penetrating the casing wall of a wellbore and introducing a fluid into the adjacent penetration. The downhole device includes an expansion piston that extends with sufficient force to seal at least one end of the device against a wellbore casing of relatively large diameter. A projectile is subsequently fired from the device to penetrate the engaged casing and provide a selected path of egress for squeeze cementing or the like therethrough. Thereafter, the device is released from its fixed position in the wellbore by retraction of the piston and retrieved therefrom. The device is disclosed with the expansion piston and method of operation therefor shown and described in several embodiments including explosive and hydraulic actuated mechanisms. | 4 |
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims the benefit under 35 U.S.C. §119(e) of the earlier filing date of U.S. Provisional Application Ser. No. 61/218,696 filed on Jun. 19, 2009, the contents of which are hereby incorporated by reference.
FIELD OF THE INVENTION
[0002] This application discloses an invention which is related, generally and in various embodiments, to a device for supplying a liquid to a machine, such as a vaporizer.
BACKGROUND OF THE INVENTION
[0003] Liquid anesthetics are often packaged in glass bottles and shipped to a location where they may be used to anesthetize a patient undergoing a medical or dental procedure. Such anesthetics may also be used to induce analgesia in a patient undergoing a medical or dental procedure. In order to administer the anesthetic, the contents of the glass bottle are placed in a vaporizer. The vaporizer can vaporize the anesthetic and provide the vaporized anesthetic in a desired amount to the patient.
[0004] Inhalable anesthetics are typically volatile substances with relatively low boiling points and high vapor pressure. Preferably, there is little or no release of anesthetic to the atmosphere during handing. The opening of a bottle containing vaporizer can be covered by a closing mechanism having an outlet port. To transfer the liquid anesthetic to a vaporizer, however, the outlet port must be opened. Since it is unwise to expose medical personnel performing a procedure to an anesthetic, and since anesthetics are expensive, devices have been developed to minimize the release of anesthetic from a bottle to the environment surrounding a vaporizer. These devices, however, have failed to conveniently and effectively minimize the release of anesthetic.
SUMMARY OF THE INVENTION
[0005] This application discloses an apparatus and system for transferring a liquid, such as an anesthetic, from the outlet port of a reservoir to a machine while effectively and conveniently minimizing the release of anesthetic. In one embodiment, the apparatus and system can include a first valve movable between a first position and a second position; a first housing surrounding the first valve; a second valve slidably connected to the first valve and movable between a third position and a fourth position; and a second housing which surrounds the second valve; wherein the apparatus defines a first opening, a second opening, and a receiver passage between the first and second openings. In another embodiment, the apparatus can include a first valve movable between a first position and a second position; a first housing which surrounds the first valve; a plunger member surrounded by the first housing, wherein the plunger member is movable between a third position and a fourth position; a second valve slidably connected to the plunger member, wherein the second valve is movable between a fifth position and a sixth position; and a second housing which surrounds the second valve; wherein the apparatus defines a first opening, a second opening, and a passageway between the first and second openings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] FIG. 1 illustrates various embodiments of a system for the flow of liquid.
[0007] FIG. 2A illustrates a receiver apparatus in the closed position according to various embodiments.
[0008] FIG. 2B shows a cross section of FIG. 2A .
[0009] FIG. 3A illustrates the receiver apparatus in the open position according to various embodiments.
[0010] FIG. 3B shows a cross section of FIG. 3A .
[0011] FIG. 4A illustrates the receiver apparatus in the closed position according to other embodiments.
[0012] FIG. 4B shows a cross section of FIG. 4A .
[0013] FIG. 5A illustrates the receiver apparatus in the open position according to other embodiments.
[0014] FIG. 5B shows a cross section of FIG. 5A .
DETAILED DESCRIPTION OF THE INVENTION
[0015] The accompanying drawings are intended to provide further understanding of the invention and are incorporated in and constitute a part of the description of the invention. The drawings illustrate various embodiments of the invention and together with the description illustrate principles of the invention.
[0016] The drawings should not be taken as implying any necessary limitation on the essential scope of invention. The drawings are given by way of non-limitative example to explain the nature of the invention.
[0017] For a more complete understanding of the instant invention reference is now made to the following description taken in conjunction with accompanying drawings.
[0018] The various features of novelty which characterize the invention are pointed out specifically in the claims which are a part of this description. For a better understanding of the invention, reference should be made to the drawings and descriptive matter in which there are illustrated and described preferred embodiments of invention.
[0019] Referring now to the drawings, wherein like numerals designate identical or corresponding parts throughout the referred views, FIG. 1 shows various embodiments of a system for the flow of liquid. Specifically, FIG. 1 shows the general flow of liquid from a reservoir 1 to the receiver apparatus 2 to a machine 3 . The reservoir 1 can be a glass bottle or any other container capable of containing a liquid, such as a liquid anesthetic. At its opening, the reservoir 1 can include an outlet port 4 (see FIGS. 3A and 3B ) to threadedly connect to the receiver apparatus 2 . As will be described below, the receiver apparatus 2 can include a valve system through which the liquid must travel to reach the machine 3 . In this embodiment, the machine 3 is a vaporizer that dispenses anesthetic to a person undergoing a medical procedure.
[0020] FIG. 2A shows various embodiments of a receiver apparatus 2 , where the receiver apparatus 2 is in the closed position. The receiver apparatus 2 is supported by a base 5 . Above a first housing 6 is a mating collar for receiving a reservoir outlet port 4 . The first housing 6 and mating collar 7 surround a first valve 8 , the stem 9 of which is also visible in FIG. 2A .
[0021] FIG. 2B shows a cross section of FIG. 2A at cross axis “A.” The first valve 8 can be movable between a first position and a second position. A first valve biasing member 10 , such as a spring, can connect to the first valve 8 and the first housing 6 , and can bias the movement between the first and second position. The movement of the first valve 8 between the first position and the second position can be guided by a guide pin 11 connected to the first housing 6 and a guide pin bore 12 in the first valve 8 . The mating collar 7 defines a threading 13 for receiving a reservoir outlet port 4 . A sealing member 14 , such as an o-ring, provides a seal between the mating collar 7 and the first housing 6 . A first valve sealing member 15 , such as an o-ring, can be in contact with the first valve 8 and can prevent the flow of liquid entering a first opening 16 of the receiver apparatus 2 . The first valve 8 can further include a first valve cam surface 17 adjacent to a stem 18 of a second valve 19 .
[0022] FIG. 2B further shows a housing connector member 30 connector member that can connect the first housing 6 and a second housing 20 . The housing connector member and the second housing 20 can surround the second valve 19 . The second valve 19 can be movable between a first position and a second position. A second valve biasing member 21 , such as a spring, can connect to the second valve 19 and the second housing 20 , and can bias the second valve's 19 movement between its first and second positions. The movement of the second valve 19 between its first and second positions can be guided in a manner similar to the guide pin 11 and guide pin bore 12 arrangement described with regard to the first valve 8 . A second valve sealing member 22 , such as an o-ring, can be in contact with the second valve 19 and can prevent liquid in the receiver apparatus 2 from flowing out a second opening 23 of the receiver apparatus 2 .
[0023] FIG. 3A shows various embodiments of the receiver apparatus 2 , where the receiver apparatus 2 has received a reservoir outlet port 4 and is in the open position.
[0024] FIG. 3B shows a cross section of the receiver apparatus 2 of FIG. 3A at cross axis “A.” The reservoir outlet port 4 has a reservoir outlet passage through which liquid can flow to the receiver apparatus 2 . The reservoir outlet port 4 can engage the mating collar 7 by threading 13 . An outlet port sealing member 25 , such as an o-ring, can provide a seal between the outlet port 4 and the receiver apparatus 2 . The reservoir outlet port 4 can further include a plug member 26 . When the reservoir outlet port 4 engages the mating collar 7 , the plug member 26 can press the stem 9 of the first valve 8 and overcome the first valve biasing member 10 , thereby moving the first valve 8 to its second position and opening a first valve passage 27 .
[0025] The second valve 19 can be slidably connected to the first valve 8 . When the first valve 8 begins to move to the second position, the first valve cam surface 17 of the first valve 8 can push the stem 18 of the second valve 19 , thereby overcoming the second valve biasing member 21 , moving the second valve 19 to its second position, and opening a second valve passage 28 . When opened, the first 27 and second 28 valve passages combine to create a receiver passage 29 through which liquid from the reservoir 1 and the first opening 16 can flow to the second opening 23 and, ultimately, to the machine 3 .
[0026] FIG. 4A shows various alternative embodiments of the receiver apparatus 2 , where the receiver apparatus 2 is in the closed position. Similar to FIG. 2A , the figure shows a mating collar 7 , a first housing 6 , and a base 5 . But by contrast, FIG. 4A also includes an activation member 31 for opening and closing the second valve 19 .
[0027] FIG. 4B shows a cross section of the receiver apparatus 2 of FIG. 4A at cross axis “A.” The figure is similar to FIG. 2B in several respects. Among other similarities, the receiver apparatus 2 of FIG. 4 B shows a first valve 8 movable between a first and second position and surrounded by a first housing 6 , a second valve 19 movable between a first and second position and surrounded by a second housing 20 and a housing connector member 30 , and first 15 and second 22 valve sealing members to help prevent the flow of liquid when the receiver apparatus 2 is in the closed position. Also similar, the mating collar 7 is connected to the first housing 6 and defines a threading 13 for receiving a reservoir outlet port 4 , and the receiver apparatus 2 includes a first opening 16 and a second opening 23 .
[0028] But by contrast, the receiver apparatus 2 of FIG. 4B includes the activation member 31 connected to a plunger member 32 . The activation member 31 can be any device connected to or part of a plunger member 32 for opening and closing the second valve 19 . In this figure, the activation member 31 is a cam that is positioned between the first housing 6 and the second housing 20 . The activation member 31 may rotate about the housing connector member 30 and can move between a first position and a second position. The plunger member 32 and its plunger cap 33 can also be moveable between a first and second position and can be surrounded by the first housing 6 . A plunger biasing member 34 , such as a spring, can connect to the plunger member 32 and the first housing 6 , and can bias the movement of the plunger member 32 between its first and second positions. The plunger member 32 can also include a plunger cam surface 35 adjacent to the stem 18 of the second valve 19 .
[0029] FIG. 5A shows various alternative embodiments of the receiver apparatus 2 , where the receiver apparatus 2 of FIG. 4A has received a reservoir outlet port 4 and is in the open position.
[0030] FIG. 5B shows a cross section of the receiver apparatus 2 of FIG. 5A at cross axis “A.” Similar to FIG. 3B , this figure shows, among other things, the reservoir outlet port 4 , the reservoir outlet passage 24 , the reservoir sealing member 25 , and the threading 13 by which the reservoir outlet port 26 can engage the mating collar 7 . Also similar to FIG. 3B , the reservoir outlet port 4 can include a plug member 26 such that, when the reservoir outlet port 4 engages the mating collar 7 , the plug member 26 can move the first valve 8 to its second position and thereby open the first valve passage 27 .
[0031] But by contrast, the second valve 19 of FIG. 5B is slidably connected to the plunger member 32 , not the first valve 8 . Thus, when the reservoir outlet port 4 engages the mating collar 7 , the first valve passage 27 may be open while the second valve passage 28 remains closed. To open the second valve passage 28 , the activation member 31 can be moved in any suitable manner such that the activation member 31 pushes the plunger member 32 and overcomes the plunger biasing member 34 , thereby moving the plunger member 32 to its second position. In FIG. 5B , the activation member 31 is a cam that is positioned between the first housing 6 and the second housing 20 , and when the activation member 31 is rotated about the housing connector member 30 from its position in FIG. 4A to its position in FIG. 5A , the housing connector member 30 pushes down the plunger cap 33 and the plunger member 32 .
[0032] When the plunger member 32 begins to move to its second position, the plunger cam surface 35 of the plunger member 32 can push the stem 18 of the second valve 19 and overcome the second valve biasing member 21 , thereby moving the second valve 19 to its second position and opening the second valve passage 28 . As in the receiver apparatus 2 of FIG. 3B , when the first 27 and second 28 valve passages are opened they combine to create a receiver passage 29 through which liquid from the reservoir 1 and the first opening 16 can flow to the second opening 23 and, ultimately, to the machine 3 .
[0033] The various embodiments of FIGS. 4A-5B can provide additional safety to users by opening the first 27 and second 28 valve passages in separate stages. For example, if the receiver apparatus 2 was connected to the reservoir outlet port 4 but not the machine 3 , liquid would not automatically flow through the receiver passage 29 , but would require the additional movement, manual or otherwise, of the activation member.
[0034] It is to be understood that the descriptions of the present invention have been simplified to illustrate characteristics that are relevant for a clear understanding of the present invention. Those of ordinary skill in the art may recognize that other elements or steps are desirable or required in implementing the present invention. However, because such elements or steps are well known in the art, and because they do not facilitate a better understanding of the present invention, a discussion of such elements or steps is not provided herein. The disclosure herein is directed to all such variations and modifications to such elements and methods known to those skilled in the art.
[0035] It is to be understood that the invention may assume various alternative orientations and step sequences, except where expressly specified to the contrary. It is also to be understood that the specific devices and processes illustrated in the attached drawings, and described in this specification are simply exemplary embodiments of the inventive concepts defined in the appended claims. Hence, specific dimensions and other physical characteristics relating to the embodiments disclosed herein are not to be considered as limiting, unless the claims expressly state otherwise.
[0036] Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described, and accordingly all suitable modifications and equivalents may be regarded as falling within the scope of the invention as defined by the claims that follow. | An apparatus and system for transferring a liquid, such as an anesthetic, from the outlet port of a reservoir to a machine while effectively and conveniently minimizing the release of anesthetic. In one embodiment, the apparatus and system can include a first valve movable between a first position and a second position; a first housing surrounding the first valve; a second valve slidably connected to the first valve and movable between a third position and a fourth position; and a second housing which surrounds the second valve; wherein the apparatus defines a first opening, a second opening, and a receiver passage between the first and second openings. In another embodiment, a movable plunger can be slidably connected to the second valve. | 0 |
RELATED APPLICATIONS
[0001] This application claims the benefit of U.S. Provisional Application Ser. No. 62/060,789, filed on Oct. 7, 2014 which is incorporated herein by reference.
FIELD OF THE INVENTION
[0002] The present invention relates to a composite oxygen ion transport membrane in which a dense layer having electronic and ionic conducting phases is supported on a porous support layer. More particularly, the present invention relates to such a composite oxygen ion transport membrane in which the electronic phase is a cobalt containing perovskite-like metallic oxide, the ionic phase is a stabilized zirconia and the porous support layer is formed of a partially stabilized zirconia.
BACKGROUND
[0003] Composite oxygen ion transport membranes have been proposed for a variety of uses that involve the production of essentially pure oxygen by separation of oxygen from an oxygen containing feed through oxygen ion transport through such membrane. For example, each membrane can be used in combustion devices to support oxy-fuel combustion or for partial oxidation reactions involving the production of a synthesis gas.
[0004] In such membranes, the oxygen ion transport principally occurs within a dense layer that allows both oxygen ions and electrons transport at elevated temperatures. The oxygen from an oxygen containing feed ionizes on one surface of the membrane and the resultant oxygen ions are driven through the dense layer and emerge on the opposite side thereof to recombine into elemental oxygen. In the recombination, electrons are liberated and are transported back through the membrane to ionize the oxygen.
[0005] Such membranes can employ two phases, an ionic phase to conduct the oxygen ions and an electronic phase to conduct the electrons. In order to minimize the resistance of the membrane to the ionic transport, such membranes are made as thin as practical and are supported on porous support layers. The resulting composite oxygen transport membrane can be fabricated as a planar element or as a tube in which the dense layer is situated either on the inside or the outside of the tube.
[0006] An example of a composite oxygen ion transport membrane is disclosed in U.S. Pat. No. 5,240,480 that has a dense layer supported on two porous layers. The dense layer can be formed of an ionic conducting phase that contains yttrium stabilized zirconia and an electronic conducting phase that is formed from platinum or another noble metal. The porous layer adjacent to the dense layer is active and is capable of conducting oxygen ions and electrons. The other porous layer can be yttrium stabilized zirconia or calcium-stabilized zirconia.
[0007] U.S. Pat. No. 5,478,444 discloses a two-phase material capable of transporting oxygen ions and electrons. The oxygen ion conducting phase can be a metallic cerium oxide incorporating an yttrium stabilizer and a dopant that can be iron or cobalt. The electronic conducting phase is a perovskite that contains lanthanum, strontium, magnesium and cobalt or lanthanum, strontium cobalt and iron.
[0008] U.S. Pat. No. 5,306,411 discloses a dual-phase membrane having an ionic conducting phase formed from Sc 2 O 3 -stabilized zirconia. The electronic conducting phase can be a perovskite material containing, for example lanthanum, strontium, irons, chromium and cobalt. The resultant dense layer can be supported on an yttria-stabilized zirconia.
[0009] U.S. Pat. No. 7,556,676 discloses a dual-phase membrane having an ionic conducting fluorite phase formed of Sc-doped zirconia and an electronic conducting perovskite phase containing lanthanum, strontium, chromium, iron, and a small amount of vanadium. The dense membrane is supported on a thick 3 mol % yttria-stabilized zirconia (3YSZ) substrate. To densify the vanadium-containing perovskite, a reducing atmosphere of hydrogen and nitrogen must be used. The dense membrane also has two optional layers: a porous fuel oxidation layer to reduce the electrochemical resistance for fuel oxidation and a porous layer on the air side to facilitate oxygen reduction to oxygen ions. The main problems with this membrane are its low oxygen flux and fast degradation of oxygen flux during long-term operation. The low flux and fast degradation might be related to the membrane fabrication process in reducing environment under which the perovskite phase may react with zirconia to form an electrically insulating third phase and densification of both fuel oxidation and air reduction layers.
[0010] To address these problems, U.S. Pat. No. 8,795,417 B2 discloses a dual-phase oxygen transport membrane consisting of a vanadium-free perovskite phase and Sc-doped zirconia phase supported on a thick 3YSZ substrate. The perovskite phase which contains lanthanum, strontium, chromium, iron and no vanadium is densified by sintering in air at temperatures from 1400 to 1430° C. The sintering process in air eliminates the formation of an electrically insulating third phase and reduces the fabrication cost. A porous fuel oxidation layer is formed from a calcium-containing perovskite and a doped zirconia. The fuel oxidation layer made of calcium-containing perovskites is more refractory and therefore, tends to have a more stable microstructure during high-temperature operation. However, one problem with this oxygen transport membrane is that the 3YSZ porous support after high temperature sintering experiences phase transformation from tetragonal to monoclinic when stored at room temperature in ambient air. The phase transformation is accompanied by about 5% volume increase and results in cracking of the porous support or delamination of the coating from the porous support.
[0011] As will be discussed the present invention provides a composite oxygen ion transport membrane that incorporates materials to enable fabrication to be accomplished in a more cost effective manner than in the prior art. Also, the present membrane is more durable than prior art membranes by avoiding the detrimental tetragonal-to-monoclinic phase transformation of the porous support. Furthermore, the materials used in all three active layers are similar in composition so the shrinkage of each layer is closely matched during membrane fabrication, results in minimal residual stress. The current oxygen transport membrane also exhibits improved oxygen flux and reduced degradation of oxygen flux during long term operation due to the inherent properties of the composition of the dense separation layer, fuel oxidation layer, and surface exchange layer and the fabrication process.
SUMMARY OF THE INVENTION
[0012] The present invention may be characterized as a composite oxygen ion transport membrane comprising a dense separation layer having an electronic phase and an ionic phase and a porous support layer. The electronic phase and ionic phase in the dense separation layer exhibit a close thermal expansion match to each other and minimal chemical expansion so that the dense separation layer remains dense after multiple thermal cycles or after exposure to an oxygen chemical potential gradient. Furthermore, the dense separation layer and porous support layer exhibit a close thermal expansion match to each other and minimal chemical expansion so that the dense separation layer and porous support layer remain strongly adhered after multiple thermal cycles or after exposure to an oxygen chemical potential gradient. In addition, the porous support layer is formulated from a composition that does not undergo a phase transition at low temperatures during reactor cool-down or storage at ambient conditions. This eliminates the problem with prior art materials where a phase transition of the porous support layer, and concurrent volume expansion of the material, at ambient conditions causes the dense separation layer to delaminate from the porous support layer or causes the porous support layer to crack. The electronic phase of the dense layer comprises (La 1-x Sr x ) w Cr 1-y-z Fe y Co z O 3-δ , where x is from about 0.1 to about 0.3, w is from about 0.93 to about 1.0, y is from about 0.15 to about 0.45, z is from about 0.03 to about 0.1, and δ renders the compound charge neutral; whereas the ionic phase of the dense layer comprises Zr 1-x′ Sc x′ A y′ O 2-δ , where x′ is from about 0.1 to about 0.22, y′ is from about 0.01 to about 0.04, and A is Y or Ce or mixtures of Y and Ce. The porous support layer is formed of Zr 1-x″ A x″ O 2-δ , where x″ is from about 0.05 to about 0.13, A is Y or Sc or Al or Ce or mixtures of Y, Sc, Al, and Ce.
[0013] There are many advantages of the materials used in the present invention over the prior art. A principal advantage of the present invention is that all the perovskite materials used in the active layers have very similar compositions and their thermal expansion is closely matched to that of the ionic conducting phase. Furthermore, all materials have limited chemical expansion and this is particularly important for the perovskite chosen for the electronic phase of the dense layer. In this regard, the use of such perovskite is particularly advantageous as opposed to a metal in that a noble metal would have to be used to prevent oxidation. The obvious problem with the use of a noble metal is one of expense. Furthermore, the support is particularly robust due to the use of a partially stabilized zirconia composition that does not experience a phase transition from tetragonal-to-monoclinic at ambient temperature.
[0014] In some embodiments of the present invention, a porous intermediate layer can be provided between the dense layer and the porous support layer. Such porous intermediate layer can also be comprised of the electronic phase and the ionic phase similar to that of the dense layer.
[0015] Furthermore, a surface exchange layer, overlying the dense layer can be provided so that the dense layer is located between the surface exchange layer and the porous intermediate layer and wherein the surface exchange layer comprises an electronic conductor and an ionic conductor. The electronic conductor of the surface exchange layer preferably comprises (La 1-x′″ Sr x′″ ) w′″ Cr 1-y′″-z′″ Fe y′″ Co z′″ O 3-δ , where x′″ is from about 0.1 to about 0.3, w′″ is from about 0.93 to about 1, y′″ is from about 0.25 to about 0.45, z′″ is from about 0.03 to about 0.1, and δ renders the compound charge neutral. The ionic conductor of the surface exchange layer further comprises Zr 1-x iv Sc x iv A y iv O 2-δ , where x iv is from about 0.1 to about 0.22, y iv is from about 0.01 to about 0.04, and A is Y or Ce.
[0016] Preferably, the ionic phase constitutes from about 35 percent to 65 percent by volume of each of the dense layer and the intermediate porous layer, with the remainder comprising the electronic phase materials. More preferably, the ionic phase constitutes from about 50 percent to 60 percent by volume of the dense layer and about 40 percent by volume of the intermediate porous layer. Similarly, the ionic conductor comprises from about 35 percent to 65 percent by volume of the surface exchange layer, and more preferably about 40 percent by volume of the surface exchange layer.
[0017] In selected embodiments, an electronic phase of the dense layer is (La 0.8 Sr 0.2 ) 0.95 Cr 0.7 Fe 0.25 Co 0.05 O 3-δ while the ionic phase is Zr 0.802 Sc 0.180 Y 0.018 O 2-δ . The porous support layer is preferably formed of Zr 0.923 Y 0.077 O 2-δ . The surface exchange layer, if used, preferably includes an ionic conductor comprising Zr 0.809 Sc 0.182 Ce 0.009 O 2-δ and an electronic conductor comprising (La 0.8 Sr 0.2 ) 0.95 Cr 0.7 Fe 0.25 Co 0.05 O 3-δ . In a particularly preferred embodiment of the present invention, the porous intermediate layer has a thickness from about 10 microns to about 30 microns, an average pore size from about 0.1 microns to about 1 micron, and a porosity from about 25 percent to about 50 percent. In one embodiment, the porous support layer can have a thickness from about 0.7 mm to about 2.5 mm, an average pore size from about 0.5 microns to about 3 microns, and a porosity from about 25 percent to about 50 percent. The surface exchange layer can have a thickness from about 10 microns to about 25 microns, an average pore size from about 0.1 microns to about 1 micron, and a porosity from about 25 percent to about 50 percent.
[0018] It is to be noted, that as used herein and in the claims, the term “pore size” means average pore diameter as determined by quantitative stereological line intersection analysis. In addition, the term “dense” layer means a layer in which the ceramic layer has no connected through porosity.
BRIEF DESCRIPTION OF THE DRAWING
[0019] FIG. 1 is a SEM micrograph of a cross-section of a composite oxygen ion transport membrane of the present invention.
DETAILED DESCRIPTION
[0020] With reference to the sole FIGURE, an oxygen ion transport membrane 1 of the present invention is illustrated. Oxygen ion transport membrane 1 has a dense layer 10 supported on a porous support 12 . Optional intermediate porous layer 14 and a surface exchange layer 16 can be provided.
[0021] Dense layer 10 functions to separate oxygen from an oxygen containing feed exposed to one surface of the oxygen ion transport membrane 10 and contains an electronic and ionic conducting phases. As discussed above, the electronic phase of (La 1-x Sr x ) w Cr 1-y-z Fe y Co z O 3-δ , where x is from about 0.1 to about 0.3 and w is from about 0.93 to about 1 and y is from about 0.15 to about 0.45, z is from about 0.03 to about 0.1. The ionic phase is Zr 1-x′-y′ Sc x′ A y′ O 2-δ , where x′ is from about 0.1 to about 0.22, y′ is from about 0.01 to about 0.04 and A is Y or Ce or a mixture of Y and Ce. The porous support layer 12 is formed of Zr 1-x″ A x″ O 2-δ , where x″ is from about 0.05 to about 0.13, A is Y or Sc or Al or Ce or mixtures thereof.
[0022] Oxygen ion transport membrane 1 is specifically designed to be used in connection with oxy-fuel combustion applications as well as applications involving chemical reactions. The application of the present invention is not, however, limited to such uses. In applications involving fuel combustion, the use of intermediate porous layer 14 enhances the rate of fuel oxidation at that interface by providing a high surface area where fuel can react with oxygen or oxygen ions under the formation of partial or complete oxidation products. The oxygen ions diffuse through the mixed conducting matrix of this intermediate porous layer 14 towards the porous support 12 and react with the fuel that diffuses inward from the porous support 12 into this porous intermediate layer 14 . Preferably, porous intermediate layer 14 is formed from the same electronic and ionic phases as dense layer 10 .
[0023] Any embodiment can incorporate advantageously a surface exchange layer 16 that overlies the dense layer opposite to the porous intermediate layer 14 if the same is used. Surface exchange layer 16 enhances the oxygen surface exchange rate by enhancing the surface area of the dense layer 10 while providing a path for the resulting oxygen ions to diffuse through the mixed conducting oxide phase to the dense layer 10 and for oxygen molecules to diffuse through the open pore space to the same. The surface exchange layer 16 therefore, reduces the loss of oxygen chemical potential driving force due to the surface exchange process and thereby increases the achievable oxygen flux. As indicated above, it can also be a two-phase mixture containing an electronic conductor composed of (La 1-x′″ Sr x′″ ) w′″ Cr 1-y′″-z′″ Fe y′″ Co z′″ O 3-δ , where x′″ is from about 0.1 to about 0.3, w′″ is from about 0.93 to 1, y′″ is from about 0.15 to 0.45, z′″ is from about 0.03 to 0.15 and δ renders the compound charge neutral and an ionic conductor composed of Zr 1-x iv -y iv Sc x iv A y iv O 2-δ , where x iv is from about 0.1 to about 0.22, y iv is from about 0.01 to about 0.04 and A is Y or Ce or Al or mixtures thereof.
[0024] In a particularly preferred embodiment of the present invention, the dense layer 10 incorporates an electronic phase composed of (La 0.8 Sr 0.2 ) 0.95 Cr 0.7 Fe 0.25 Co 0.05 O 3-δ and an ionic phase composed of Zr 0.802 Sc 0.180 Y 0.018 O 2-δ . In such embodiment, the porous support layer 12 is formed of Zr 0.923 Y 0.077 O 2-δ and the surface exchange layer incorporates an ionic conductor composed of Zr 0.809 Sc 0.182 Ce 0.009 O 2-δ and an electronic conductor composed of (La 0.8 Sr 0.2 ) 0.95 Cr 0.7 Fe 0.25 Co 0.05 O 3-δ . Preferably, the porous intermediate layer 14 has a thickness from about 10 microns to about 30 microns, an average pore size from about 0.1 microns to about 1 microns and a first porosity from about 25 percent to about 50 percent. Porous support layer 12 has a thickness from about 0.7 mm to about 2.5 mm, an average pore size from about 0.5 microns to about 3 microns and a porosity from about 25 percent to about 50 percent. The surface exchange layer 16 has a thickness from about 10 microns to about 25 microns, an average pore size from about 0.1 microns to about 1 microns and a porosity from about 25 percent to about 50 percent.
[0025] As an example of fabricating an oxygen transport membrane element of the present invention, a porous support layer 12 is first fabricated from yttrium stabilized zirconia powder having a chemical formula of Zr 0.923 Y 0.077 O 2-δ (hereinafter, 4YSZ) The particle size of such powder is d 50 =0.6 μm (about a 50 percentile of the particles have a particle size of below 0.6 μm.) The powder is then mixed with carbon black having a particle size of a d 50 from about 0.1 to about 1 μm and Poly(methyl methacrylate) (PMMA) having a particle size of a d 50 of about 1.5 um. The mixture contains about 9 percent carbon black, 19 percent PMMA and a remainder of the yttrium stabilized zirconia powder. Binder is then added to the mixture of YSZ Powder, carbon black, and PMMA which is then poured into a high shear sigma blade mixer. Water and dispersant are then added while the mixing blades are rotating in order to form an extrudable paste.
[0026] The paste is loaded into a ram extruder fitted with a die designed to form the desired tube size. The ram is moved forward and the paste is subjected to a pressure of about 1000 psi to form a green tube which exits the die. After the green tube is formed, the tube is placed on slowly rotating rollers and allowed to dry for 1-2 days. After drying, the tube is cut to size, drilled, and can then be fired from 950-1200° C. for 2-4 hours to achieve reasonable strength for further handling. After firing, the resulting tube can be checked for porosity, permeability/tortuosity and stored in a dry oven at about 60° C.
[0027] After firing the green tube, intermediate porous layer 14 is then formed. A mixture of about 30 grams of powders having electronic and ionic phases with the chemical formulas, (La 0.8 Sr 0.2 ) 0.95 Cr 0.7 Fe 0.25 Co 0.05 O 3-δ (LSCrFCo) and Zr 0.802 Sc 0.180 Y 0.018 O 2-δ (YScZ), respectively, is prepared so that the mixture contains about 60% of LSCrFCo and about 40% of YScZ by volume. To the mixture, 25 grams of toluene, 5 grams of Ferro binder (Product ID B73210), 200 grams of 1.5 mm diameter YSZ grinding media are added. The mixture is then milled for about 6 hours to form a slurry having a particle size d 50 of about 0.3 μm). About 4.5 grams of carbon black having a particle size of about d 50 of 0.8 μm and 0.3 grams of surfactant KD-1 dissolved in 15 grams of toluene are then added to the slurry and milled for additional 2 hours. The slurry is then coated by meniscus coating with a coating speed of 6-10 meters per hour on the outer wall of the tube which is then fired at about 1200° C. for 4 hours in air.
[0028] The dense layer 10 is then applied to the coated tube. A mixture weighing about 70 grams is prepared that contains the same powders as used in forming the intermediate porous layer 14 , discussed above, except that the ratio between LSCrFCo and YScZ is about 50/50 by volume. To this mixture, 170 grams of toluene, 36 grams of the same Ferro binder mentioned above, 1100 grams of 1.5 mm diameter YSZ grinding media are added and the same is milled for about 24 hours to form a slurry having a particle size d 50 of about 0.3 μm. The formed slurry is then applied as a coating on top of layer 14 also by meniscus coating process with similar coating speed. The tube is then stored dry prior to co-firing the layers 14 and 10 in a controlled environment, as described below.
[0029] The coated tube is slowly heated in flowing nitrogen to about 1380° C. and held at the same temperature for about 6 hours for the cobalt containing electronic conducting perovskites to properly sinter. During sintering, the oxygen partial pressure of the atmosphere in the furnace is controlled below 20 Pa. The tube is then cooled in nitrogen to complete the sintering process. The sintered tube is checked for flow coefficient v, as defined below:
[0000]
Cv
=
q
0.471
N
2
p
1
1
G
g
T
1
[0030] where q is the flow rate, N 2 is a constant, p 1 is the inlet pressure, G g is the gas specific gravity, and T 1 is the absolute upstream temperature. The Cv of the sintered tube should not exceed 1.5×10 −5 .
[0031] Surface exchange layer 16 is then applied. The surface exchange layer 16 has the same compositions and ratio of the electronic and ionic phases as the intermediate porous layer 14 , mentioned above. To prepare the slurry, 80 grams of the electronic and ionic mixture, 28.8 grams of toluene, 19.2 grams of ethyl alcohol, 16 grams of the same Ferro binder mentioned above, 1.6 grams of surfactant KD-1, about 500 grams of 1.5 mm diameter YSZ grinding media are added and the resultant mixture is milled for about 2 hours to form a slurry having a particle size d 50 of about 0.4 μm. About 12 grams of carbon black are added to the slurry and it is milled for additional 2 hours. The slurry is then applied as a coating on top of the sintered dense layer 10 again by meniscus coating with roughly the same coating speed. The coated tube is then dried and fired at 1250° C. for two hours in air. The Cv of the tube after cathode sintering is checked again to make sure no significant change has occurred.
[0032] The resultant tubes have the preferred thickness, pore size and porosity within the ranges outlined above, namely, the porous intermediate layer 14 has a thickness of about 15 microns, an average pore size from about 0.1 microns to about 0.5 microns and a porosity from about 25 percent to about 50 percent. Porous support layer 12 has a thickness of about 1 mm, an average pore size from about 1 micron to about 3 microns and a porosity of about 35 percent. The surface exchange layer 16 has a thickness from about 10 microns to about 20 microns, an average pore size from about 0.1 microns to about 0.5 microns and a porosity from about 40 percent to about 60 percent. In one embodiment, dense layer 10 has a thickness from about 10 microns to 20 microns and no connected porosity.
[0033] It is to be noted that in one embodiment of the present invention, the particle size of the chromite/zirconia slurry for deposition of the intermediate and dense separation layers 14 and 10 is preferably in a range from about 0.3 microns to about 0.35 microns. Although other particle sizes may be used, membranes fabricated from such slurries with particle sizes in the range from about 0.3 microns to about 0.35 microns indicated minimal reactivity between the two phases and with shrinkage matching the porous zirconia support.
[0034] While the invention has been described with respect to a preferred embodiment, as will occur to those skilled in the art, numerous changes, additions and omissions may be made without departing from the spirit and scope of the present invention provided for in the appended claims. | A composite oxygen ion transport membrane having a dense layer, a porous support layer, an optional intermediate porous layer located between the porous support layer and the dense layer and an optional surface exchange layer, overlying the dense layer. The dense layer has electronic and ionic phases. The ionic phase is composed of scandia doped, yttrium or cerium stabilized zirconia. The electronic phase is composed of a metallic oxide containing lanthanum, strontium, chromium, iron and cobalt. The porous support layer is composed of zirconia partially stabilized with yttrium, scandium, aluminum or cerium or mixtures thereof. The intermediate porous layer, if used, contains the same ionic and electronic phases as the dense layer. The surface exchange layer is formed of an electronic phase of a metallic oxide of lanthanum and strontium that also contains chromium, iron and cobalt and an ionic phase of scandia doped zirconia stabilized with yttrium or cerium. | 1 |
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