초록 ▼

A transducer assembly includes first and second stators which are axially aligned with, and bear upon opposite sides of a proof mass. The stators and proof mass are clamped together by means of a sleeve having a side portion with upper and lower flanges projecting therefrom. An inner sleeve element,

A transducer assembly includes first and second stators which are axially aligned with, and bear upon opposite sides of a proof mass. The stators and proof mass are clamped together by means of a sleeve having a side portion with upper and lower flanges projecting therefrom. An inner sleeve element, formed from a material having a different coefficient of thermal expansion than the side portion, is disposed between the flanges. The temperature of the sleeve is controlled such that the inner sleeve element produces a tensile stress on said flanges, increasing the spacing therebetween. The flanges are then joined to the stators. Thereafter, the temperature of the sleeve is controlled such that the tensile stress produced by the inner sleeve element on the flanges is reduced producing a compression force tending to reduce the flange spacing. This compression force is transmitted to the stators and proof mass as a controlled compressive axial preload.

대표청구항 ▼

1. A method for producing a controlled preload between the first and second mating sections of a transducer assembly, the method comprising the steps of: (a) providing a sleeve member, said sleeve member having a side portion with predeterminedly spaced apart upper and lower flanges projecting th

1. A method for producing a controlled preload between the first and second mating sections of a transducer assembly, the method comprising the steps of: (a) providing a sleeve member, said sleeve member having a side portion with predeterminedly spaced apart upper and lower flanges projecting therefrom, each flange configured to be joined with one of said mating sections, said side portion being formed of a first material having a first coefficient of thermal expansion, said sleeve member further including an inner sleeve element disposed intermediate said flanges and having a predetermined spacing with respect to said flanges, said inner sleeve element being formed of a second material having a second coefficient of thermal expansion; (b) controlling the temperature of said sleeve member such that said inner sleeve element exerts a tensile stress on said flanges increasing the spacing therebetween; (c) joining each flange to one of said first and second mating sections; and (d) controlling the temperature of said sleeve member such that said tensile stress on said flanges is reduced thereby producing a compression force on said flanges tending to reduce the spacing therebetween, said compression force being transmitted to said first and second mating sections to produce a predetermined compressive preload therebetween. 2. The method of Claim 1 wherein said first and second mating sections are generally cylindrical in shape, the sensor assembly being formed by aligning the longitudinal axes of said mating sections, thereby forming a cylindrical outer surface, and applying an axial compression force therebetween, wherein step (a) comprises the steps of: (i) providing said sleeve member configured such that said side portion is arcuate, having a radius substantially equal to the radius of said cylindrical outer surface, (ii) providing said flanges projecting from said side portion into the concave side thereof, the spacing between said flanges being predeterminedly related to the axial length of said aligned mating sections, and (iii) providing said inner sleeve element arcuate in shape having substantially the same radius as said side portion, said inner sleeve element being attached to said side portion intermediate said flanges. 3. The method of claim 1 wherein step (a) comprises the step of providing said inner sleeve element formed from a material having a higher coefficient of thermal expansion than said side portion, said inner sleeve element being dimensioned such that at a first temperature said inner sleeve element exerts a relatively high tensile stress on said flanges whereas at a second, reduced temperature said inner sleeve exerts a relatively low tensile stress on said flanges; step (b) comprises the step of heating said sleeve member to said first temperature; and step (d) comprises the step of cooling said sleeve member to said second temperature. 4. The method of claim 2 wherein step (a) comprises the step of providing said inner sleeve element formed from a material having a higher coefficient of thermal expansion than said side portion, said inner sleeve element being dimensioned such that at a first temperature said inner sleeve element exerts a relatively high tensile stress on said flanges whereas at a second, reduced temperature said inner sleeve exerts a relatively low tensile stress on said flanges; step (b) comprises the step of heating siad sleeve member to said first temperature; and step (d) comprises the step of cooling said sleeve member to said second temperature. 5. The method of claim 3 wherein: step (a) comprises the further step of providing said inner sleeve element formed of a memory alloy, said memory alloy being preformed to a dimension such that said inner sleeve element exerts a relatively low tensile stress on said flanges at said second temperature, whereas at an elevated memory temperature said inner sleeve element exerts a relatively high tensile stress on said flanges; and step (b) comprises the step of heating said sleeve member to said memory temperature. 6. The method of claim 4 wherein: step (a) comprises the further step of providing said inner sleeve element formed of a memory alloy, said memory alloy being preformed to a dimension such that said inner sleeve element exerts a relatively low tensile stress on said flanges at said second temperature, whereas at an elevated memory temperature said inner sleeve element exerts a relatively high tensile stress on said flanges; and step (b) comprises the step of heating said sleeve member to said memory temperature. 7. The method of claim 1 wherein: step (a) comprises the step of providing said inner sleeve element formed of a memory alloy having a lower coefficient of thermal expansion than said side portion, said memory alloy being formed to exert a relatively high tensile force on said flanges at a first temperature whereas at a second, elevated memory temperature said inner sleeve element exerts a relatively low tensile force on said flanges, said inner sleeve element, at said first temperature, being disposed intermediate said flanges with said flanges under tension to increase the spacing therebetween; and step (d) comprises the step of controlling the temperature of said sleeve member to said memory temperature. 8. The method of claim 2 wherein: step (a) comprises the step of providing said inner sleeve element formed of a memory alloy having a lower coefficient of thermal expansion than said side portion, said memory alloy being formed to exert a relatively high tensile force on said flanges at a first temperature whereas at a second, elevated memory temperature said inner sleeve element exerts a relatively low tensile force on said flanges, said inner sleeve element, at said first temperature, being disposed intermediate said flanges with said flanges under tension to increase the spacing therebetween; and, step (d) comprises the step of controlling the temperature of said sleeve member to said memory temperature. 9. A method for assembling a transducer comprising the steps of: (a) providing a transducer assembly including first and second stators and a proof mass, said proof mass having a mass element suspended for movement within an outer support member, the stators being positioned on opposite sides of the proof mass and including bearing surfaces for bearing on opposite surfaces of said outer support member, said stators further having provided receiving surfaces for receiving an applied preload force; (b) providing a sleeve member, said sleeve member having a side portion with predeterminedly spaced apart upper and lower flanges projecting therefrom, each flange configured to be joined with one of said stator receiving surfaces, said side portion being formed of a first material having a first coefficient of thermal expansion, said sleeve member further including an inner sleeve element disposed intermediate said flanges, said inner sleeve element being formed of a second material having a second coefficient of thermal expansion; (c) controlling the temperature of said sleeve member such that said inner sleeve element exerts a tensile stress on said flanges predeterminedly increasing the spacing therebetween; (d) joining each flange to one of said first and second stators; and (e) controlling the temperature of said sleeve member such that said tensile stress on said flanges is reduced thereby producing a compression force on said flanges tending to reduce the spacing therebetween, said compression force being transmitted to said first and second stators to produce a predetermined preload between said first and second stators and said outer support member. 10. The method of claim 9 wherein: step (a) includes the step of providing said first and second stators and said proof mass configured generally cylindrically, the assembly of the stators and the proof mass including aligning the longitudinal axes thereof, thereby forming a cylindrical outer surface; step (b) includes the steps of: (i) providing said sleeve member configured such that said side portion is arcuate, having a radius substantially equal to the radius of said cylindrical outer surface, (ii) providing said flanges projecting from said side portion into the concave side thereof, the spacing between said flanges being predeterminedly related to the axial length of said axially aligned first and second stators and proof mass, and (iii) providing said inner sleeve element arcuate in shape having substantially the same radius as said side portion, said inner sleeve element being attached to said side portion intermediate said flanges. 11. The method of claim 9 wherein: step (b) comprises the step of providing said inner sleeve element formed of a material having a higher coefficient of thermal expansion than the coefficient of thermal expansion of said side portion, the inner sleeve element being dimensioned such that at a first temperature said inner sleeve element exerts a relatively high tensile stress on said flanges whereas at a second, reduced temperature said inner sleeve exerts a relatively low tensile stress on said flanges; step (c) comprises the step of heating said sleeve member to said first temperature; and step (e) comprises the step of cooling said sleeve member to said second temperature. 12. The method of claim 10 wherein: step (b) comprises the step of providing said inner sleeve element formed of a material having a higher coefficient of thermal expansion than the coefficient of thermal expansion of said side portion, the inner sleeve element being dimensioned such that at a first temperature said inner sleeve element exerts a relatively high tensile stress on said flanges whereas at a second, reduced temperature said inner sleeve exerts a relatively low tensile stress on said flanges; step (c) comprises the step of heating said sleeve member to said first temperature; and step (e) comprises the step of cooling said sleeve member to said second temperature. 13. The method of claim 11 wherein: step (a) comprises the further step of providing said inner sleeve element formed of a memory alloy, said memory alloy being preformed to a dimension such that it exerts a relatively low tensile stress on said flanges at said second temperature, whereas at an elevated, memory temperature said metal alloy exerts a relatively high tensile stress on said flanges; and step (c) comprises the step of heating said sleeve member to said memory temperature. 14. The method of claim 12 wherein: step (a) comprises the further step of providing said inner sleeve element formed of a memory alloy, said memory alloy being preformed to a dimension such that it exerts a relatively low tensile stress on said flanges at said second temperature, whereas at an elevated, memory temperature said metal alloy exerts a relatively high tensile stress on said flanges; and step (c) comprises the step of heating said sleeve member to said memory temperature. 15. The method of claim 9 wherein: step (b) comprises the step of providing said inner sleeve element formed of a memory alloy having a lower coefficient of thermal expansion than said side portion, said memory alloy being formed to exert a relatively high tensile force on said flanges at a first temperature whereas at a second, elevated memory temperature said memory alloy exerts a relatively low tensile force on said flanges, said inner sleeve element, at said first temperature, being disposed intermediate said flanges with said flanges under tension to increase the spacing therebetween; and, step (e) comprises the step of controlling the temperature of said sleeve member to said memory temperature. 16. The method of claim 10 wherein: step (b) comprises the step of providing said inner sleeve element formed of a memory alloy having a lower coefficient of thermal expansion than said side portion, said memory alloy being formed to exert a relatively high tensile force on said flanges at a second temperature whereas at a first, elevated, memory temperature said memory alloy exerts a relatively low tensile force on said flanges, said inner sleeve element, at said first temperature, being disposed intermediate said flanges with said flanges under tension to increase the spacing therebetween; and, step (e) comprises the step of controlling the temperature of said sleeve member to said memory temperature. 17. The method of claim 9 wherein: step (a) comprises the further step of providing said proof mass outer support member with predeterminedly positioned contact portions, said contact portions defining the areas of contact between said proof mass and said first and second stators; step (b) comprises the step of providing said sleeve member flanges configured to be joined with said receiving surfaces on said first and second stators such that said flanges are axially aligned with said contact portions. 18. The method of claim 17 wherein step (a) comprises the steps of: (i) providing capacitance plate pick-off areas on opposite sides of said mass element, and (ii) providing said predeterminedly positioned contact portions on an axis that intersects the centroid of said capacitive plate pick-off areas. 19. The method of claim 10 wherein: step (a) comprises the further steps of: (i) providing capacitive plate pick-off areas on opposite sides of said mass element, and (ii) providing said proof mass outer support member with contact portions for defining the areas of contact between said proof mass assembly and said first and second stators, said contact portions being predeterminedly positioned on an axis that intersects the centroid of said capacitive plate pick-off areas. 20. The method of claim 19 wherein step (b) comprises the step of providing said sleeve member having said flanges configured to be joined with said receiving surfaces on said first and second stators such that the compression force exerted by said sleeve member on said transducer assembly is axially aligned with said contact portions. 21. A transducer assembly comprising: a sensor assembly having first and second axially aligned mating sections, each mating section having a receiving surface for receiving an applied clamping force to clamp said mating sections together; and clamping means for applying a controlled compressive axial preload to said mating sections, said clamping means comprising a sleeve member having a side portion with predeterminedly spaced apart upper and lower flanges, each flange configured to be joined with one of said mating section receiving surfaces, said side portion being formed of a first material having a first coefficient of thermal expansion, said sleeve member further including an inner sleeve element disposed intermediate said flanges, said inner sleeve element being formed of a second material having a second coefficient of thermal expansion, said flanges being joined to said mating section receiving surfaces at a first temperature such that said inner sleeve element exerts a tensile stress on said flanges predeterminedly increasing the spacing therebetween, the sleeve member thereafter being controlled to a second temperature such that said tensile stress on said flanges is reduced thereby producing a compression force on said flanges tending to reduce the spacing therebetween, said compression force being transmitted to said first and second mating sections to produce a predetermined preload therebetween. 22. The transducer assembly of claim 21 wherein: the outer surface of said axially aligned mating sections is generally cylindrical in shape, and said clamping means sleeve member is configured such that said side portion is arcuate having a radius substantially equal to the radius of said axially aligned mating sections outer surface, and said flanges project from said side member into the concave side thereof. 23. The transducer of claim 21 wherein said inner sleeve element is formed from a material having a higher coefficient of thermal expansion than said side portion, said inner sleeve element being dimensioned such that at said first temperature said inner sleeve exerts a relatively high tensile stress on said flanges whereas at said second, reduced temperature said inner sleeve element exerts a relatively low tensile stress on said flanges. 24. The transducer of claim 23 wherein said inner sleeve element is formed of a memory alloy, said memory alloy being preformed to a dimension such that said inner sleeve element exerts a relatively low tensile stress on said flanges at said second temperature, whereas at an elevated, memory temperature said inner sleeve element exerts a relatively high tensile stress on said flanges. 25. The transducer of claim 22 wherein said inner sleeve element is formed from a material having a higher coefficient of thermal expansion than said side portion, said inner sleeve element being dimensioned such that at said first temperature said inner sleeve exerts a relatively high tensile stress on said flanges whereas at said second, reduced temperature said inner sleeve element exerts a relatively low tensile stress on said flanges. 26. The transducer of claim 25 wherein said inner sleeve element is formed of a memory alloy, said memory alloy being preformed to a dimension such that said inner sleeve element exerts a relatively low tensile stress on said flanges at said second temperature, whereas at an elevated, memory temperature said inner sleeve element exerts a relatively high tensile stress on said flanges. 27. The transducer assembly of claim 21 wherein said inner sleeve element is formed of a memory alloy having a lower coefficient of thermal expansion than said side portion, said memory alloy being preformed to exert a relatively high tensile force on said flanges at said first temperature whereas at a second, elevated memory temperature said inner sleeve element exerts a relatively low tensile force on said flanges. 28. The transducer assembly of claim 22 wherein said inner sleeve element is formed of a memory alloy having a lower coefficient of thermal expansion than said side portion, said memory alloy being preformed to exert a relatively high tensile force on said flanges at said first temperature whereas at a second, elevated memory temperature said inner sleeve element exerts a relatively low tensile force on said flanges. 29. A transducer assembly comprising: a proof mass including a mass element suspended for movement within an outer support member; first and second stators, the stators being positioned on opposite sides of said proof mass in axial alignment therewith and including bearing surfaces for bearing on opposite surfaces of said outer support member, said stators having predetermined receiving surfaces for receiving an applied clamping force; clamping means for applying a controlled compressive axial preload to said first and second stators and said proof mass, said clamping means comprising a sleeve member having a side portion with predeterminedly spaced apart upper and lower flanges projecting therefrom each flange configured to be joined with one of said stator receiving surfaces, said side portion being formed of a first material having a first coefficient of thermal expansion, said sleeve member further including an inner sleeve element disposed intermediate said flanges, said inner sleeve element being formed of a second material having a second coefficient of thermal expansion, said flanges being joined to said stator receiving surfaces at a first temperature such that said inner sleeve element exerts a tensile stress on said flanges predeterminedly increasing the spacing therebetween, the sleeve member thereafter being controlled to a second temperature such that said tensile stress on said flanges is reduced thereby producing a compression force on said flanges tending to reduce the spacing therebetween, said compression force being transmitted to said first and second stators to produce a predetermined preload therebetween. 30. The transducer assembly of claim 29 wherein the outer surfaces of said proof mass and said stators are generally cylindrical in shape, the assembly of said proof mass and stators presenting a generally cylindrical outer surface, and wherein said clamping means sleeve member is configured such that said side portion is arcuate having a radius substantially equal to the radius of said transducer assembly cylindrical outer surface, and said flanges project from said side member into the concave side thereof. 31. The transducer assembly of claim 30 wherein said proof mass outer support member is provided with predeterminedly positioned contact pads for defining the contact areas between the stators and the proof mass, and said flanges and said receiving surfaces on said first and second stators are configured such that the compressive preload transmitted from the sleeve member to said proof mass and stators is axially aligned with said contact areas. 32. The transducer assembly of claim 31 wherein capacitive plate pick-off areas are provided on opposite sides of said mass element, and wherein said outer support contact pads are aligned with respect to the centroid of said capacitive plate pick-off areas. 33. The transducer of claim 32 wherein said inner sleeve element is formed from a material having a higher coefficient of thermal expansion than said side portion, said inner sleeve exerting a relatively high tensile stress on said flanges at said first temperature whereas at said second, reduced temperature said inner sleeve element exerts a relatively low tensile stress on said flanges. 34. The transducer of claim 29 wherein said inner sleeve element is formed of a memory alloy, said memory alloy being preformed to a dimension such that said inner sleeve element exerts a relatively low tensile stress on said flanges at said second temperature, whereas at an elevated, memory temperature said inner sleeve element exerts a relatively high tensile stress on said flanges. 35. The transducer assembly of claim 31 wherein said inner sleeve element is formed of a memory alloy having a lower coefficient of thermal expansion than said side portion, said memory alloy being preformed to exert a relatively high tensile force on said flanges at said first temperature whereas at a second, elevated memory temperature said inner sleeve element exerts a relatively low tensile force on said flanges.