Patent US3629774A successfully refreshed from Google Patents.
US3629774A
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Progressively collapsible variable resistance element
Assignee: Scientific Advances Inc
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Filing: 1968-10-21
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Granted: 1971-12-21
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Expires: 1988-10-21
Abstract
Abstract A resistance element of elastic material has at least an interconnected portion coated with a nonfriable electrically conductive material forming an electrical path that changes its resistance as a function of the state of tension or compression of the resistance element. A conductive material is prepared from particulate electrical conductive material, an elastic binder and a solvent. Pretreatment of an elastic material of elastomer foam prior to application of conductive material produces a useful resistance element.
Inventors
- 👤 Nelson A Crites
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 19:20
CPC Classifications
H; H01; H01C; H01C10/00; H01C10/10; H01C10/106
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
23 words
A resistance element as in claim 1, wherein said conductive particles comprise about 10 to 25 percent of the volume of said coating.
Claim 2
Dependent Claim
16 words
A resistance element as in claim 1, wherein said elastic binder consists essentially of silicone rubber.
Claim 3
Dependent Claim
15 words
A resistance element as in claim 1, wherein said conductive particles consist essentially of carbon.
Claim 4
Dependent Claim
23 words
A resistance element as in claim 1, wherein said elastic material consists essentially of a nonconductive elastomer foam having an interconnected cellular network.
Claim 5
Dependent Claim
35 words
A resistance element as in claim 1, wherein said elastic material consists essentially of a porous mass of particles of elastomer foam adherent at their contact points, each said particle having an interconnected cellular network.
Claim 6
Dependent Claim
118 words
A progressively collapsible variable resistance element comprising a three-dimensional network of interconnecting strands of solvent-impregnated and swollen then dried and unswollen eLastic material integrally interconnected by nexuses at spaced points to form a multitude of reticulated cells substantially all faces of which are open and free from membranous elastic material; and a nonfriable elastic coating, substantially covering said interconnecting strands and nexuses without substantially filling said open faces, comprising an elastic binder and electrically conductive particles dispersed therein and having been applied to the network in its solvent-swollen condition and prestressed by the subsequent drying and shrinking to form a substantially smooth outer surface at which said conductive particles are substantially, but not completely, embedded in said binder.
Claim 7
Dependent Claim
26 words
A resistance element as in claim 7, wherein the average thickness of said coating is less than about 0.5 of the radius of said interconnecting strands.
Claim 8
Dependent Claim
19 words
A resistance element as in claim 7, wherein said network has about 10 to 100 faces per lineal inch.
Claim 9
Dependent Claim
22 words
A resistance element as in claim 7, comprising also an intermediate layer of elastic material between the skeletal network and said coating.
Claim 10
Dependent Claim
16 words
A resistance element as in claim 10, wherein said intermediate layer consists essentially of silicone rubber.
Claim 11
Dependent Claim
16 words
A resistance element as in claim 7, wherein the skeletal network consists essentially of polyurethane resin.
Claim 12
Dependent Claim
16 words
A resistance element as in claim 7, wherein the particulate conductive material consists essentially of carbon.
Claim 13
Dependent Claim
130 words
A progressively collapsible variable resistance element comprising: an interwoven structure of fibrous strands; a layer of elastic material substantially covering said strands and bonding them at spaced points of intersection to form a three-dimensional interconnected solvent-impregnated and swollen then dried and unswollen network substantially free of membranous material in the areas between strands, said elastic layer imparting elasticity to the structure as a whole; and a nonfriable elastic coating substantially covering said network without substantially filling said areas between strands comprising an elastic binder and electrically conductive particles dispersed therein and having been applied to the network in its solvent-swollen condition and prestressed by the subsequent drying and shrinking to form a substantially smooth outer surface at which said conductive particles are substantially, but not completely, embedded in said binder.
Claim 14
Dependent Claim
18 words
A resistance element as in claim 14, wherein said layer of elastic material consists essentially of silicone rubber.
Claim 15
Dependent Claim
16 words
A resistance element as in claim 14, wherein the particulate conductive material consists essentially of carbon.
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) | 1974-12-20 | 1975-06-21 | 1975-12-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-12-20 | 1979-06-21 | 1979-12-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-12-20 | 1983-06-21 | 1983-12-21 | $7700.00 | Window Closed / Lapsed |