US3670283A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Motor overload protector
Assignee: Therm O Disc Inc
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Filing: 1970-10-02
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Granted: 1972-06-13
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Expires: 1990-10-02
Abstract
Abstract A motor overload protector is disclosed which includes a cantilever mounted bimetal snap element provided with a mobile contact at its free end. The snap element moves the mobile contact into and out of engagement with the fixed contact carried by the body. A central stop post is provided by the body located to engage the central portion of the snap element when the contacts are open. A pull-in calibration screw engages the opposite side of the bimetal when the contacts are closed to calibrate the temperatures on opening. The snap travel of the installed snap element is reduced to limit the stresses imposed on the bimetal and reduce the tendancy to fatigue or crack. Contact life is improved because the contacts reliably snap both open and closed.
Inventors
- 👤 Ronald L Holden
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 22:51
CPC Classifications
H; H01; H01H; H01H37/00; H01H37/02; H01H37/32; H01H37/52; H01H37/54; H01H37/5418; H02; H02K; H02K11/00; H02K11/20; H02K11/25
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
29 words
An overload protector as set forth in claim 1 wherein said body means includes a body stop preventing substantially all overtravel of said snap means when said contacts open.
Claim 2
Dependent Claim
28 words
An overload protector as set forth in claim 2 wherein said snap means are spaced from said body stop before said snap means to a contact closed position.
Claim 3
Dependent Claim
28 words
An overload protector as set forth in claim 1 wherein said snap means are provided with stiffening means which strengthen said snap means adjacent to said mobile contact.
Claim 4
Dependent Claim
27 words
An overload protector as set forth in claim 4 wherein said stiffening means is provided by a lateral bend in the bimetal adjacent to said mobile contact.
Claim 5
Dependent Claim
124 words
An overload protector as set forth in claim 1 wherein said snap means is formed so that when its movement is unrestrained it has first and second free snap positions and a predetermined snap range equal to the distance between said free snap positions, the location of said fixed contact determining one installed snap position and the location of said first stop surface substantially determining the other installed snap position, bOth of said installed snap positions being displaced from their corresponding free snap positions, said first stop surface and said fixed contact being located so that said snap means has an installed snap range which is equal to the distance between said installed snap positions and is substantially less than said free snap range.
Claim 6
Dependent Claim
39 words
An overload protector as set forth in claim 6 wherein said snap means is resiliently biased to maintain said snap means in engagement with said first stop surface when said snap means is in said other installed snap position.
Claim 7
Dependent Claim
39 words
An overload protector as set forth in claim 1 wherein said second stop surface operates when said contacts are closed to apply force to said snap means intermediate its ends urging said snap means toward its contact closed position.
Claim 8
Dependent Claim
25 words
An overload protector as set forth in claim 8 wherein said second stop surface is adjustable to control the opening temperature of said snap means.
Claim 9
Dependent Claim
24 words
An overload protector as set forth in claim 9 wherein said second stop surface is provided by a screw carried by said body means.
Claim 10
Dependent Claim
41 words
An overload protector as set forth in claim 10 wherein said screw reduces the operating temperature of said snap means on opening of said contacts when compared to the corresponding operating temperature of said snap means when unrestrained in its movement.
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) | 1975-06-13 | 1975-12-13 | 1976-06-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-06-13 | 1979-12-13 | 1980-06-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-06-13 | 1983-12-13 | 1984-06-13 | $7700.00 | Window Closed / Lapsed |