Extended range pressure transducers

• US 4,454,765 A
• Filed: 11/03/1981
• Issued: 06/19/1984
• Est. Priority Date: 11/03/1981
• Status: Expired due to Term

• Current Assignee: Arthur S. Lodge
• Original Assignee: Arthur S. Lodge
• Inventors: Lodge, Arthur S.
• Primary Examiner(s): WOODIEL, DONALD
• Application Number:
  US06/317,604
• Time in Patent Office: 959 Days
• Field of Search: 73/724, 73/730, 73/718, 73/756, 73/431, 361/283
• US Class Current: 73/724
• CPC Class Codes: G01L 9/0072 using variations in capacitance

Abstract

The useful range of the disclosed pressure transducers is extended by isolating the sensing means of the transducer from bending moments produced in the transducer body by the fluid pressure being measured. The isolating means may comprise an isolating ring interposed between the body and the sensor means, disposed behind a diaphragm which is attached to the isolating ring and the body. The isolating ring is connected to the body by means adapted to hold the sensor means in an established relationship with the diaphragm while being of a character to avoid transmitting bending moments, whereby the isolating ring and the sensor means are isolated from bending moments developed in the body due to fluid pressure.

Claims

1. A pressure measuring device, comprising substantially flat diaphragm means;

a body backing up and supporting said diaphragm means;

said body having an opening behind said diaphragm means;

said diaphragm means covering said opening and affording a flexible resilient diaphragm extending across said opening;

sensor means disposed in said opening behind said diaphragm for sensing any deflection of said diaphragm due to fluid pressure thereon;

a mechanical isolating ring mounted in said opening behind said diaphragm;

first connecting means between said body and said isolating ring;

and second connecting means between said isolating ring and said sensor means for supporting said sensor means in an established relationship with said diaphragm;

said first and second connecting means being of a character to hold said sensor means in an established relationship with said diaphragm while being of a character to avoid transmitting bending moments whereby said isolating ring and said sensor means are isolated from bending moments which may be developed in said body due to the fluid pressure which is being measured;

said first connecting means comprising a shoulder on said body in said opening and facing away from said diaphragm,

a portion on said isolating ring for engaging said shoulder,

and screw threaded means between said body and said isolating ring for holding said portion of said isolating ring against said shoulder while avoiding the transmission of bending moments between said body and said isolating ring,

said screw threaded means comprising a plurality of small machine screws extending between said isolating ring and said body.

2. A pressure measuring device, comprising substantially flat diaphragm means,

a body backing up and supporting said diaphragm means;

said body having an opening behind said diaphragm means;

said diaphragm means covering said opening and affording a flexible resilient diaphragm extending across said opening;

sensor means disposed in said opening behind said diaphragm for sensing any deflection of said diaphragm due to fluid pressure thereon;

a mechanical isolating ring mounted in said opening behind said diaphragm;

first connecting means between said body and said isolating ring;

and second connecting means between said isolating ring and said sensor means for supporting said sensor means in an established relationship with said diaphragm;

said first and second connecting means being of a character to hold said sensor means in an established relationship with said diaphragm while being of a character to avoid transmitting bending moments whereby said isolating ring and said sensor means are isolated from bending moments which may be developed in said body due to the fluid pressure which is being measured;

said sensor means including a sensor supporting member;

said second connecting means comprising an internal shoulder in said isolating ring and facing away from said diaphragm,

and resilient clamping means for resiliently clamping said sensor supporting member against said internal shoulder.

3. A pressure measuring device, comprising substantially flat diaphragm means,

a body backing up and supporting said diaphragm means;

said body having an opening behind said diaphragm means;

said diaphragm means covering said opening and affording a flexible resilient diaphragm extending across said opening;

sensor means disposed in said opening behind said diaphragm for sensing any deflection of said diaphragm due to fluid pressure thereon;

a mechanical isolating ring mounted in said opening behind said diaphragm;

said isolating ring having an end surface flush with said body and engaging said diaphragm;

means for securing said diaphragm to said end surface of said isolating ring;

first connecting means between said body and said isolating ring;

and second connecting means between said isolating ring and said sensor means for supporting said sensor means in an established relationship with said diaphragm;

said first and second connecting means being of a character to hold said sensor means in an established relationship with said diaphragm while being of a character to avoid transmitting bending moments whereby said isolating ring and said sensor means are isolated from bending moments which may be developed in said body due to the fluid pressure which is being measured;

said first connecting means comprising a shoulder on said body in said opening and facing away from said diaphragm;

said isolating ring having a portion thereon for engaging said shoulder;

and screw means between said isolating ring and said body for holding said portion of said isolating ring against said shoulder while avoiding the transmission of bending moments between said body and said isolating ring;

said sensor means including a sensor supporting member;

said second connecting means comprising an internal shoulder in said isolating ring and facing away from said diaphragm,

and resilient clamping means for resiliently clamping said sensor supporting member against said internal shoulder.

4. A pressure measuring device according to claim 3,

said resilient clamping means comprising a retaining ring received in said opening behind said isolating ring,

mating screw threads on said retaining ring and said body whereby said retaining ring can be screwed into said body,

and means including a resiliently compressible clamping ring compressed between said retaining ring and said sensor supporting member for resiliently clamping said supporting member against said internal shoulder.

5. A pressure measuring device, comprising substantially flat diaphragm means,

a body having a substantially flat surface backing up and supporting said diaphragm means,

said diaphragm means having a portion overlapping said flat surface and engaging said flat surface throughout substantially all of said portion,

said body having an opening behind said diaphragm means,

said diaphragm means covering said opening and affording a flexible resilient diaphragm extending across said opening,

said diaphragm being substantially flat throughout its entire extent across said opening,

sensor means disposed in said opening behind said diaphragm for sensing any deflection of said diaphragm due to fluid pressure thereon,

an isolating ring mounted in said opening and interposed between said body and said sensor means for supporting said sensor means,

said isolating ring having an opening therein,

said sensor means including an electrical insulator extending through said opening in said isolating ring and retaining means for retaining said insulator in said last-mentioned opening,

said body having an annular shoulder in said opening and facing away from said diaphragm,

said isolating ring having a peripheral portion thereon for engaging said shoulder,

and connecting means between said isolating ring and said body for holding said peripheral portion of said isolating ring in engagement with said shoulder to hold said sensor means in an established relationship with said diaphragm while avoiding the transmission of bending moments between said body and said isolating ring.

6. A pressure measuring device according to claim 5,

said connecting means comprising screw threaded means between said body and said isolating ring for holding said peripheral portion of said isolating ring against said shoulder.

7. A pressure measuring device according to claim 5,

said connecting means comprising a retaining ring disposed in said opening behind said isolating ring and having first screw threads on said retaining ring,

and second screw threads on said body in said opening for receiving said first screw threads whereby said retaining ring can be screwed into said opening against said isolating ring.

8. A pressure measuring device according to claim 5,

said connecting means comprising a plurality of fastening elements between said isolating ring and said body.

9. A pressure measuring device according to any of claims 5-7 and 8,

including means for attaching said diaphragm to said isolating ring.

10. A pressure measuring device according to any of claims 5-7, 8 and 9,

said retaining means comprising screw threaded means for securing said sensor means on said isolating ring.

11. A pressure measuring device according to any of claims 5-7 and 9,

said retaining means including mating screw threads on said insulator and said isolating ring for removably securing said insulator on said isolating ring.

12. A pressure measuring device according to any of claims 5-7 and 9,

said retaining means including mating screw threads on said sensor means and said isolating ring for securing said sensor means on said ring.

13. A pressure measuring device, comprising substantially flat diaphragm means,

a body backing up and supporting said diaphragm means,

said body having an opening behind said diaphragm means,

said diaphragm means covering said opening and affording a flexible resilient diaphragm extending across said opening,

said diaphragm being substantially flat throughout its entire extent across said opening,

sensor means disposed in said opening behind said diaphragm for sensing any deflection of said diaphragm due to fluid pressure thereon,

an isolating ring mounted in said opening and interposed between said body and said sensor means for supporting said sensor means,

said isolating ring having an end surface for engaging said diaphragm,

said body having an annular shoulder in said opening and facing away from said diaphragm,

said isolating ring having a peripheral portion thereon for engaging said shoulder to position said isolating ring with said end surface engaging said diaphragm but without substantially deflecting said diaphragm,

and connecting means between said isolating ring and said body for holding said peripheral portion of said isolating ring in engagement with said shoulder to hold said sensor means in an established relationship with said diaphragm while avoiding the transmission of bending moments between said body and said isolating ring.

14. A pressure measuring device according to claim 13, including means for securing said diaphragm to said end surface of said isolating ring.

15. A pressure measuring device according to claim 13 or 14,

said connecting means including threaded means between said body and said isolating ring for holding said peripheral portion of said isolating ring against said shoulder.

16. A pressure measuring device according to claim 13 or 14,

said connecting means comprising a plurality of small machine screws extending between said isolating ring and said body.

17. A pressure measuring device according to claim 13 or 14,

said connecting means comprising a plurality of fastening elements for fastening said peripheral portion of said isolating ring to said shoulder.

18. A pressure measuring device according to claim 13 or 14,

including screw threaded means for holding said sensor means on said isolating ring.

19. A pressure measuring device according to claim 13 or 14,

said isolating ring including an internal shoulder facing away from said diaphragm,

and resilient clamping means for resiliently clamping said sensor means against said last mentioned shoulder.

20. A pressure measuring device according to claim 19,

said resilient clamping means including a resiliently compressible clamping ring for engaging said sensor means,

a retaining ring received in said opening behind said isolating ring,

and mating screw threads on said retaining ring and said body for removably securing said retaining ring in said opening for resiliently compressing said clamping ring against said sensor means.

21. A pressure measuring device according to claim 13 or 14,

said connecting means comprising a retaining ring disposed in said opening behind said isolating ring,

and mating screw threads on said retaining ring and said body for removably clamping said retaining ring against said peripheral portion of said isolating ring.

22. A pressure measuring device according to claim 13 or 14,

including mating screw threads on said sensor means and said isolating ring for securing said sensor means on said isolating ring.

23. A pressure measuring device, comprising substantially flat diaphragm means,

a body backing up and supporting said diaphragm means,

said body having an opening behind said diaphragm means,

said diaphragm means covering said opening and affording a flexible resilient diaphragm extending across said opening,

said diaphragm being substantially flat throughout its entire extent across said opening,

sensor means disposed in said opening behind said diaphragm for sensing any deflection of said diaphragm due to fluid pressure thereon,

an isolating ring mounted in said opening and interposed between said body and said sensor means for supporting said sensor means,

said body having an annular shoulder in said opening and facing away from said diaphragm,

said isolating ring having a peripheral portion thereon for engaging said shoulder,

and connecting means between said isolating ring and said body for holding said peripheral portion of said isolating ring in engagement with said shoulder to hold said sensor means in an established relationship with said diaphragm while avoiding the transmission of bending moments between said body and said isolating ring,

said connecting means comprising a plurality of small machine screws extending between said isolating ring and said body.

24. A pressure measuring device, comprising substantially flat diaphragm means,

a body backing up and supporting said diaphragm means,

said body having an opening behind said diaphragm means,

said diaphragm means covering said opening and affording a flexible resilient diaphragm extending across said opening,

said diaphragm being substantially flat throughout its entire extent across said opening,

sensor means disposed in said opening behind said diaphragm for sensing any deflection of said diaphragm due to fluid pressure thereon,

an isolating ring mounted in said opening and interposed between said body and said sensor means for supporting said sensor means,

said body having an annular shoulder in said opening and facing away from said diaphragm,

said isolating ring having a peripheral portion thereon for engaging said shoulder,

and connecting means between said isolating ring and said body for holding said peripheral portion of said isolating ring in engagement with said shoulder to hold said sensor means in an established relationship with said diaphragm while avoiding the transmission of bending moments between said body and said isolating ring,

said sensor means including a sensor mounting member,

said isolating ring having an internal shoulder therein facing away from said diaphragm,

and resilient clamping means for resiliently clamping said sensor supporting member against said last mentioned shoulder.

25. A pressure measuring device according to claim 24,

said resilient clamping means comprising a resiliently compressible clamping ring engaging said sensor supporting member,

and a retaining ring received in said opening behind said isolating ring for compressing said clamping ring against said sensor supporting member,

said retaining ring and said body having mating screw threads thereon whereby said retaining ring can be screwed into said opening.