US4793277A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Detector of the inflation pressure of motor vehicle tires
Assignee: Robert Bosch GmbH
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Filing: 1986-11-05
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Granted: 1988-12-27
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Expires: 2006-11-05
Abstract
Abstract A tire pressure detector for motor vehicles which is to be fastened to a wheel rim comprises a pressure switch actuated by the air pressure in the tire for monitoring the tire pressure. The pressure switch includes a reference pressure chamber with an electrically conductive switching diaphragm which closes the chamber toward the tire and which cooperates with a contact pin of the reference pressure chamber and an electric oscillating circuit connected to the latter in the detector housing. The reference pressure chamber (23) is axially clamped between a supporting ring and a spacing ring of insulating material in the metallic detector housing by a radial collar, which is formed, so that an annular gap is formed between the collar and the inner wall of the detector housing.
Inventors
- 👤 Lothar Haas
- 👤 Gerhard Hettich
- 👤 Manfred Kamp
- 👤 Hans-Dieter Schmid
- 👤 Hans Schrumpf
- 👤 Berthold Walter
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 10:10
CPC Classifications
H; H01; H01H; H01H35/00; H01H35/24; H01H35/26; H01H35/28; B; B60; B60C; B60C23/00; B60C23/02; B60C23/04; B60C23/0408; B60C23/0491; B60C23/0498
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
190 words
In a tire pressure detector for motor vehicles, comprising a pressure switch which is to be fastened to a circumference of a wheel rim and is actuated by air pressure in the tire for monitoring the tire pressure and which comprises an electrically conductive switching diaphragm; a member forming a reference pressure chamber closed toward the tire by said electrically conductive switching diaphragm; a contact pin supported in said member and cooperating with the switching diaphragm; electric oscillating circuit, the contact pin and the switching diaphragm being connected with said electric oscillating circuit; and a detector housing in which the reference pressure chamber is thermally insulated from the wheel rim, the improvement comprising a supporting ring (22), a spacing ring (24) of insulating material, said detector housing being metallic, said member (23) having a radially projecting collar (36), the member forming reference pressure chamber (23) being axially clamped between the supporing ring (22) and the spacing ring (24) in the metallic detector housing (16) at the collar (36) thereof so that an annular gap (37) is formed between the collar (36) and an inner wall of the detector housing (16).
Claim 2
Dependent Claim
190 words
In a tire pressure detector for motor vehicles, comprising a pressure switch which is to be fastened to a circumference of a wheel rim and is actuated by air pressure in the tire for monitoring the tire pressure and which comprises an electrically conductive switching diaphragm; a member forming a reference pressure chamber closed toward the tire by said electrically conductive switching diaphragm; a contact pin supported in said member and cooperating with the switching diaphragm; electric oscillating circuit, the contact pin and the switching diaphragm being connected with said electric oscillating circuit; and a detector housing in which the reference pressure chamber is thermally insulated from the wheel rim, the improvement comprising a supporting ring (22), a spacing ring (24) of insulating material, said detector housing being metallic, said member (23) having a radially projecting collar (36), the member forming reference pressure chamber (23) being axially clamped between the supporing ring (22) and the spacing ring (24) in the metallic detector housing (16) at the collar (36) thereof so that an annular gap (37) is formed between the collar (36) and an inner wall of the detector housing (16).
Claim 3
Dependent Claim
95 words
Tire pressure detector according to claim 1, wherein said housing has an annular shoulder (18) and a flange (26) formed at a front end thereof; said switch further including an elastic sealing ring (21) and a cover plate (25), the supporting ring 22 resting on the annular shoulder (18) which is formed in the detector housing (16) via the elastic sealing ring (21), and the spacing ring (24) with the cover plate (25) connecting the member which forms the reference pressure chamber (23) at said collar (36) to the flange (26) of the housing (16).
Claim 4
Dependent Claim
38 words
Tire pressure detector according to claim 1, wherein the housing (16) is provided at its inner wall with an annular groove (38) at the level of the collar (36), said annular groove (38) enlarging the annular gap (37).
Claim 5
Dependent Claim
51 words
Tire pressure detector according to claim 1, wherein said member forming the reference pressure chamber has a flange (47) which projects axially from the collar (36), the switching diaphragm (30) lying flat on the flange (47) and being welded all around at a radial front side thereof with the flange (47).
Claim 6
Dependent Claim
29 words
Tire pressure detector according to claim 2, wherein the cover plate (25) overlaps the switching diaphragm (30) and is provided with segment-like openings (48) arranged adjacent to one another.
Claim 7
Dependent Claim
98 words
Tire pressure detector according to claim 2, wherein said supporing ring (22) has a projection (39) which projects through an opening of the annular shoulder (18) of the housing (16) and is enclosed by said sealing ring (21), said member having a contact wire (35), said switch including an insulating circuit chamber (20), the contact pin (31) and the connection wire (35) projecting through the projection (39) into the oscillating circuit chamber (20) which accommodates a toroid coil (27) with a capacitor and with the member which forms the reference pressure chamber (23) to form an oscillating circuit.
Claim 8
Dependent Claim
46 words
Tire pressure detector according to claim 6, wherein electrical connections of the toroid coil (27), capacitor and contact pin (31) are protected against the tire air by said sealing ring (21) and a sealing compound (40) positioned in the projection (39) of the supporting ring (22).
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) | 1991-12-27 | 1992-06-27 | 1992-12-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-12-27 | 1996-06-27 | 1996-12-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-12-27 | 2000-06-27 | 2000-12-27 | $7700.00 | Window Closed / Lapsed |