Adjustable pressure transducer with digital signal output
First Claim
1. A pressure transducer assembly for indicating ambient pressure over a predetermined differential pressure range having a minimum and a maximum and operable over a wide range of absolute pressures, said assembly comprising:
- a housing having an interior;
means for communicating ambient pressure to said interior; and
means supported in said housing interior for generating discrete signals over said differential pressure range each representative of a different value of said ambient pressure, said generating means including means defining a protective enclosure for preventing contamination thereof;
said generating means including a multi-resistor assembly and a contact element, one of said multi-resistor assembly and said contact element being translatable relative to the other in response to changes in said ambient pressure;
said multi-resistor assembly including an insulated substrate, a pair of spaced parallel rows of electrically conductive contact pads, the contact pads of one row being staggered relative to the contact pads in the other row, and a plurality of resistive elements connected to contact pads in said pair of rows to provide a series resistance network;
said contact element having a pair of spaced contact arms, each said arm being arranged for contact with individual pads of a different row.
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Accused Products
Abstract
A pressure transducer assembly for indicating ambient pressure over a predetermined differential pressure range having a minimum and a maximum and operable over a wide range of absolute pressures. A housing having an interior in fluid communication with ambient pressure surrounds a digital signal generator which is protected from ingressing contaminants. The digital signal generator includes a translatable electrical contact member secured to the working end of a surrounding electrically conductive bellows secured at the remaining end to the housing and a stationary multi-resistor assembly having a staggered pair of rows of spaced contact pads and miniature resistors coupled between selected pads in opposite rows to provide a series resistance network whose resistance depends on the position of the contact element, the pads and resistors being supported on an insulated substrate. The multi-resistor assembly is supported by a conductive rod which is translatable in opposite directions along the axis of the housing by a simple adjustment mechanism so that the fixed differential pressure operating range may be shifted over a wide range of absolute pressures. A plurality of transducers are mounted in a sheathed telephone feed cable at regularly spaced positions therealong, with each transducer being electrically connected to a different pair of subscriber conductors so that the pressure at any given location along the feed cable can be determined by applying a test voltage across individual subscriber conductor pairs at a remote location and noting the resistance.
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Citations
17 Claims
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1. A pressure transducer assembly for indicating ambient pressure over a predetermined differential pressure range having a minimum and a maximum and operable over a wide range of absolute pressures, said assembly comprising:
- a housing having an interior;
means for communicating ambient pressure to said interior; and
means supported in said housing interior for generating discrete signals over said differential pressure range each representative of a different value of said ambient pressure, said generating means including means defining a protective enclosure for preventing contamination thereof;
said generating means including a multi-resistor assembly and a contact element, one of said multi-resistor assembly and said contact element being translatable relative to the other in response to changes in said ambient pressure;
said multi-resistor assembly including an insulated substrate, a pair of spaced parallel rows of electrically conductive contact pads, the contact pads of one row being staggered relative to the contact pads in the other row, and a plurality of resistive elements connected to contact pads in said pair of rows to provide a series resistance network;
said contact element having a pair of spaced contact arms, each said arm being arranged for contact with individual pads of a different row.
- a housing having an interior;
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2. The apparatus of claim 1 wherein said communicating means comprises a porous member carried by said housing.
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3. The apparatus of claim 2 wherein said porous member is integral with said housing.
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4. The apparatus of claim 1 wherein said multi-resistor assembly is stationary and said contact member is translatable.
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5. The apparatus of claim 1 wherein said resistive elements are arranged to provide a logarithmic resistance scale.
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6. The apparatus of claim 1 wherein said protective enclosure includes an outer bellows member having a first end secured to said housing and a second end translatably received in said housing interior, said contact element being secured to said second end.
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7. The apparatus of claim 1 further including means for adjusting the absolute value of the minimum and maximum of said differential pressure range.
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8. The apparatus of claim 1 further including means for varying the relative position of said multi-resistor assembly and said contact element to establish the absolute value of the minimum and maximum of said differential pressure range.
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9. The apparatus of claim 8 wherein said multi-resistor assembly is carried by a rod and wherein said adjusting meAns includes means for translating said rod along the axis of said housing.
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10. A system for measuring ambient pressure at spaced locations along an enclosed volume of interest, said system comprising:
- a longitudinally extending enclosure defining said volume;
a plurality of pairs of electrical conductors extending along said volume; and
a plurality of pressure transducers each positioned along said volume at different predetermined spaced locations, each said pressure transducer having a pair of electrical signal leads coupled to a different one of said plurality of pairs of electrical conductors;
each said pressure transducer comprising a housing having an interior;
means for communicating ambient pressure to said interior; and
means coupled to said pair of electrical signal leads for generating discrete signals on said electrical signal leads over said differential pressure range, each representative of a different value of said ambient pressure, said generating means including means defining a protective enclosure for preventing contamination thereof;
said generating means including a multi-resistor assembly and a contact element, one of said multi-resistor assembly and said contact element being translatable relative to the other in response to changes in said ambient prdssure;
said multi-resistor assembly including an insulated substrate, a pair of spaced parallel rows of electrically conductive contact pads, the contact pads of one row being staggered relative to the contact pads in the other row, and a plurality of resistive elements connected to contact pads in said pair of rows to provide a series resistance network, said pads and said resistive elements being supported on said substrate;
said contact element having a pair of spaced contact arms, each said arm being arranged for contact with individual pads of a different row.
- a longitudinally extending enclosure defining said volume;
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11. The apparatus of claim 10 wherein said multi-resistor assembly is stationary and said contact member is translatable.
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12. The system of claim 10 wherein said resistive elements are arranged to provide a logarithmic resistance scale.
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13. The system of claim 10 wherein said protective enclosure includes an outer bellows member having a first end secured to said housing and a second end translatably received in said housing interior, said contact element being secured to said second end.
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14. The system of claim 10 wherein each said pressure transducer includes means for adjusting the absolute value of the minimum and maximum of said differential pressure range.
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15. The system of claim 10 wherein each said pressure transducer includes means for varying the relative position of said multi-resistor assembly and said contact element to establish the absolute value of the minimum and maximum of said differential pressure range.
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16. The system of claim 15 wherein said multi-resistor assembly is carried by a rod and wherein said adjusting means includes means for translating said rod along the axis of said housing.
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17. The system of claim 10 wherein said longitudinally extending enclosure comprises a telephone feed cable and said plurality of pairs of electrical conductors comprise individual subscriber conductors.
Specification