US3850038A
Expired / Lapsed
US
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Bi-material condition sensors
Assignee: Johnson Service Co
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Filing: 1972-10-11
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Granted: 1974-11-26
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Expires: 1992-10-11
Abstract
Abstract A bi-material sensing element is essentially rigidly mounted about the periphery. The element is mounted in an environment to sense the humidity, temperature or the like and is to provide a detectable movement normal to the plane of the element. Holes or slots of a predetermined shape are formed in the element and are equicircumferentially distributed about the center. At a critical diameter, the unit has zero sensitivity. The sensitivity of the element will increase when the holes are moved to either side of the critical diameter, with the deflection in opposite directions as the holes are located to opposite sides of the critical diameter. The sensitivity also increases with increased ratio of voids to solid material along the circle diameter on which the holes are located. The critical diameter location varies with the several factors involved in the construction of the bi-material disc.
Inventors
- 👤 P Thoma
- 👤 L Atkinson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 04:08
CPC Classifications
G; G01; G01K; G01K5/00; G01K5/48; G01K5/56; G01K5/62; G01K5/64; G01K5/68
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
136 words
A bi-material condition sensing element having integral inner and outer portions and at least a pair of outer mounting means for establishing a detectable deflection in accordance with a sensed condition, said element including superimposed materials with different coefficients of expansion with respect to a selected condition and said mounting means being spaced from each other about the outer portion and said mounting means being adapted to be essentially rigidly mounted, comprising the improvement of a plurality of separate opening means located within said element and within at least one of said materials with said material completely surrounding each opening means, said opening means being located in spaced relation to said mounting means and in spaced relation to each other, said opening means establishing and controlling the deflection characteristic of the element to said sensed condition.
Claim 2
Dependent Claim
136 words
A bi-material condition sensing element having integral inner and outer portions and at least a pair of outer mounting means for establishing a detectable deflection in accordance with a sensed condition, said element including superimposed materials with different coefficients of expansion with respect to a selected condition and said mounting means being spaced from each other about the outer portion and said mounting means being adapted to be essentially rigidly mounted, comprising the improvement of a plurality of separate opening means located within said element and within at least one of said materials with said material completely surrounding each opening means, said opening means being located in spaced relation to said mounting means and in spaced relation to each other, said opening means establishing and controlling the deflection characteristic of the element to said sensed condition.
Claim 3
Dependent Claim
32 words
The bi-material condition sensing element of claim 1 wherein said superimposed materials are coextensive and having peripheral mounting means, said plurality of separate opening means being located equicircumferentially on a common circle.
Claim 4
Dependent Claim
62 words
The bi-material condition sensing element of claim 1 wherein a first of said superimposed materials is secured to substantially less than the total area of a second of said materials and is concentrically applied thereto to define a substantially planar bi-material element with said second material having a substantially uncovered portion defining a mono-layer, said opening means being located in the mono-layer.
Claim 5
Dependent Claim
28 words
The bi-material condition sensing element of claim 3 wherein said plurality of separate opening means are located on a common circle and are equicircumferentially spaced on said circle.
Claim 6
Dependent Claim
70 words
The bi-material condition sensing element of claim 1 wherein said element is a flat, plate-like element having a center and said opening means includes a plurality of equicircumferentially distributed similar openings located on a common circle in spaced relation to the mounting means and the center of the element, said opening means defining a certain ratio of solid material and voids on a diameter through the center of the openings.
Claim 7
Dependent Claim
107 words
The bi-material condition sensing element of claim 1 being a generally flat, plate-like element with another peripheral edge and a center and wherein said mounting means is secured to said peripheral edge and said opening means are located on a circle and sized to define a selected ratio of void to solid material along said circle, said element having a zero sensitivity to said condition with said openings located at a particular located circle spaced between the mounting means and the center of the element, said deflection being in opposite directions as said diameter location varies to the opposite side of said zero condition sensitivity diameter location.
Claim 8
Dependent Claim
168 words
A bi-material condition sensing apparatus for establishing a detectable deflection in accordance with a sensed condition, a base member defining a first material layer having a first predetermined coefficient of expansion with respect to the condition being sensed, a second material layer having a selected different coefficient of expansion with respect to said condition and interconnected to said first material layer to define a bi-material sensing element, essentially fixed and rigid mounting means connected at least at opposite sides of the base member to said base member to rigidly support the base member, said base member having a plurality of separate opening means surrounded by the first material layer and spaced from each other and from the mounting means and establishing deFlection of the base member in response to variation in said condition with the movement of said element being in a direction essentially normal to a plane through the mounting means, and said opening means controlling the deflection characteristic of the base member and said second layer.
Claim 9
Dependent Claim
168 words
A bi-material condition sensing apparatus for establishing a detectable deflection in accordance with a sensed condition, a base member defining a first material layer having a first predetermined coefficient of expansion with respect to the condition being sensed, a second material layer having a selected different coefficient of expansion with respect to said condition and interconnected to said first material layer to define a bi-material sensing element, essentially fixed and rigid mounting means connected at least at opposite sides of the base member to said base member to rigidly support the base member, said base member having a plurality of separate opening means surrounded by the first material layer and spaced from each other and from the mounting means and establishing deFlection of the base member in response to variation in said condition with the movement of said element being in a direction essentially normal to a plane through the mounting means, and said opening means controlling the deflection characteristic of the base member and said second layer.
Claim 10
Dependent Claim
28 words
The bi-material condition sensing apparatus of claim 7 wherein said plurality of separate opening means are located on a common circle and are equicircumferentially spaced on said circle.
Claim 11
Dependent Claim
16 words
The bi-material condition sensing apparatus of claim 8 wherein said openings are equal sized circular openings.
Claim 12
Dependent Claim
33 words
The bi-material condition sensing apparatus of claim 9 wherein said openings are sized to define a certain ratio of void and solid material on a circle line through the centers of said openings.
Claim 13
Dependent Claim
60 words
The bi-material condition sensing apparatus of claim 7 wherein said base member is a disc-like element and said second layer is co-terminus with said element, said mounting means being rigidly affixed to the peripheral edge of said base member, said opening means including a plurality of equicircumferentially spaced openings on a circle located in spaced relation to the peripheral edge.
Claim 14
Dependent Claim
76 words
The bi-material condition sensing apparatus of claim 11 wherein said openings are selected to define a certain ratio of void to solid material along the circle of the openings, said sensing apparatus having a zero sensitivity to said condition when said holes are located on a circle spaced from the peripheral edge and from said deflection being in opposite directions as said diameter location varies to the opposite side of said zero condition sensitivity diameter location.
Claim 15
Dependent Claim
150 words
The bi-material condition sensing apparatus of claim 7 wherein said base member is a circular plate having a center and said first and second material layers are co-terminus with respect to said base member and said mounting means is rigidly affixed to the peripheral edge of said base member and said second material layer, said opening means including a plurality of equicircumferentially spaced circular openings along a selected circle, the characteristic sensitivity of said sensor being controlled by the location of said circle and including a zero sensitivity to said condition at a ratio of the circle diameter to the base member diameter with the circle spaced from the mounting means and the center of the circular plate, said deflection being in opposite direction as said diameter ratio varies to the opposite side of said diameter ratio where zero sensitivity occurs and essentially in accordance with a straight line characteristic.
Claim 16
Dependent Claim
50 words
The bi-material condition sensing apparatus of claim 13 wherein said characteristic sensitivity is also controlled by the ratio of void to solid material defined by the openings and interconnecting solid material on the circle of the openings, and said openings are of a selected size to establish a selected characteristic.
Claim 17
Dependent Claim
31 words
The bi-material condition sensing apparatus of claim 7 wherein said base member is a substantially planar member and said second material layer is affixed to one surface of said base member.
Claim 18
Dependent Claim
41 words
The bi-material condition sensing apparatus of claim 15 wherein said base member is a disc-like element having the mounting means connected to the periphery, and said opening means being located between the mounting means and the center of the base member.
Claim 19
Dependent Claim
48 words
The bi-material condition sensing apparatus of claim 7 wherein said second material is secured to substantially less than the total area of said base member and is equally applied to the base member in a circular configuration to define a substantially planar bi-material element with said base member.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-11-25 | 1978-05-27 | 1978-11-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-11-25 | 1982-05-27 | 1982-11-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-11-25 | 1986-05-27 | 1986-11-26 | $7700.00 | Window Closed / Lapsed |