US3662149A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Heated lock for motorcars
Assignee: Pebra GmbH
•
Filing: 1970-09-14
•
Granted: 1972-05-09
•
Expires: 1990-09-14
Abstract
Abstract At least one PTC thermistor whose resistance rises abruptly at a temperature near 32* F. is mounted on the casing or cylinder of a car lock and permanently connected to the car battery for heating the lock by the ohmic resistance of the thermistor without draining the battery at higher temperatures to prevent freezing of the lock. ''''In one embodiment, the thermistors, enveloped in a minimum amount of potting compound, are locked within radially extending blind bores provided in the outer surface of the casing. In another embodiment, the thermistors are positioned in any available recess on the outer surface of the casing and held in close thermal contact therewith by a split ring clamp. As a further alternative, the thermistors may be installed in a normally movable lock part, such as the cylinder.
Inventors
- 👤 Reinhard Lipinski
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 22:22
CPC Classifications
E; E05; E05B; E05B17/00; E05B17/0016; Y; Y10; Y10T; Y10T70/00; Y10T70/80
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
124 words
In a lock having a metallic casing formed with a bore and a cylinder received in said bore for rotation about an axis for opening and closing said lock, said cylinder frictionally engaging said casing during said rotation, the improvement which comprises: a. a source of electric current, 1. said casing being formed with at least one blind bore extending from the outer surface of said casing in a substantially radial direction toward said cylinder; b. a thermistor having a positive temperature coefficient; c. fastening means fastening said thermistor in said recess in intimate thermal contact with said casing, said cylinder being nearer to said thermistor than to said outer surface; and d. conductor means connecting said thermistor to said source for constant energization.
Claim 2
Dependent Claim
124 words
In a lock having a metallic casing formed with a bore and a cylinder received in said bore for rotation about an axis for opening and closing said lock, said cylinder frictionally engaging said casing during said rotation, the improvement which comprises: a. a source of electric current, 1. said casing being formed with at least one blind bore extending from the outer surface of said casing in a substantially radial direction toward said cylinder; b. a thermistor having a positive temperature coefficient; c. fastening means fastening said thermistor in said recess in intimate thermal contact with said casing, said cylinder being nearer to said thermistor than to said outer surface; and d. conductor means connecting said thermistor to said source for constant energization.
Claim 3
Dependent Claim
23 words
In a lock as set forth in claim 1, said fastening means including a potting compound in said recess and enveloping said thermistor.
Claim 4
Dependent Claim
41 words
In a lock as set forth in claim 2, said casing being formed with external threads extending about said axis on one axially terminal portion of said casing, the other axially terminal portion of said casing being formed with said recess
Claim 5
Dependent Claim
39 words
In a lock as set forth in claim 2, the resistivity of said thermistor increasing steeply when the temperature of said thermistor is raised above approximately 32* F., and changing little upon cooling of said thermistor below said temperature.
Claim 6
Dependent Claim
62 words
In a lock as set forth in claim 4, the conductivity of said thermistor below approximately 32* F. being sufficient to cause transmission of thermal energy by ohmic heating of said thermistor to said one part when said source applies a voltage of approximately 12 volts to said thermistor, the transmitted energy being sufficient to keep said one part above 32* F.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-05-09 | 1975-11-08 | 1976-05-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-05-09 | 1979-11-08 | 1980-05-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-05-09 | 1983-11-08 | 1984-05-09 | $7700.00 | Window Closed / Lapsed |