US4894639A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Pressure switch for monitoring tire pressure, particularly of motor vehicle tires
Assignee: Dr Ing HCF Porsche AG
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Filing: 1989-03-24
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Granted: 1990-01-16
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Expires: 2009-03-24
Abstract
Abstract A pressure switch for monitoring a tire pressure of a motor vehicle tire is fastened to a wheel rim and is actuated by the inflating pressure in the tire. The pressure switch comprises a reference pressure chamber which is sealed off by an electrically conductive switching diaphragm in the direction of the tire, and carries a contact pin interacting with this diaphragm. The switching diaphragm has a mass which is controlled as a function of centrifugal force in response to tire rotation such that the switching point of the pressure switch can be changed automatically as a function of vehicle speed.
Inventors
- 👤 Wolfgang Schmierer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 20:23
CPC Classifications
B; B60; B60C; B60C23/00; B60C23/02; B60C23/04; B60C23/0408
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
130 words
A pressure switch for monitoring tire pressure of motor vehicle tires, which is fastened at a wheel rim of the tire and is actuated by inflating pressure in the tire, comprising: a reference pressure chamber which faces in the direction of the tire and is sealed off from the tire by an electrically conductive switching diaphragm; the chamber supports a contact pin which interacts with this switching diaphragm to close an electric circuit between the pin and diaphragm; and the switching diaphragm has applied to it a force responsive to the tire pressure and a mass which is controlled as a function of centrifugal force indicative of tire rotational speed so that closing points of the pressure switch are determined by tire pressure that varies automatically with tire rotational speed.
Claim 2
Dependent Claim
130 words
A pressure switch for monitoring tire pressure of motor vehicle tires, which is fastened at a wheel rim of the tire and is actuated by inflating pressure in the tire, comprising: a reference pressure chamber which faces in the direction of the tire and is sealed off from the tire by an electrically conductive switching diaphragm; the chamber supports a contact pin which interacts with this switching diaphragm to close an electric circuit between the pin and diaphragm; and the switching diaphragm has applied to it a force responsive to the tire pressure and a mass which is controlled as a function of centrifugal force indicative of tire rotational speed so that closing points of the pressure switch are determined by tire pressure that varies automatically with tire rotational speed.
Claim 3
Dependent Claim
53 words
A pressure switch according to claim 1, wherein closing points of the pressure switch, as a result of the rotational speed of the tire and hence speed of the vehicle, follow a desired characteristic speed curve which provides a warning threshold for an excessively low tire pressure that increases as vehicle speed increases.
Claim 4
Dependent Claim
40 words
A pressure switch according to claim 1, wherein the switching diaphragm of the pressure switch is arranged in a vertical transverse plane which extends approximately at a right angle with respect to a direction of force of the centrifugal force.
Claim 5
Dependent Claim
40 words
A pressure switch according to claim 2, wherein the switching diaphragm of the pressure switch is arranged in a vertical transverse plane which extends approximately at a right angle with respect to the direction of force of the centrifugal force.
Claim 6
Dependent Claim
21 words
A pressure switch according to claim 1, wherein the switching diaphragm has a centric accumulation of mass opposite the switching pin.
Claim 7
Dependent Claim
21 words
A pressure switch according to claim 2, wherein the switching diaphragm has a centric accumulation of mass opposite the switching pin.
Claim 8
Dependent Claim
21 words
A pressure switch according to claim 3, wherein the switching diaphragm has a centric accumulation of mass opposite the switching pin.
Claim 9
Dependent Claim
21 words
A pressure switch according to claim 4, wherein the switching diaphragm has a centric accumulation of mass opposite the switching pin.
Claim 10
Dependent Claim
22 words
A pressure switch according to claim 1, wherein the switching diaphragm has an accumulation of mass distributed uniformly over the circumference thereof.
Claim 11
Dependent Claim
22 words
A pressure switch according to claim 2, wherein the switching diaphragm has an accumulation of mass distributed uniformly over the circumference thereof.
Claim 12
Dependent Claim
22 words
A pressure switch according to claim 3, wherein the switching diaphragm has an accumulation of mass distributed uniformly over the circumference thereof.
Claim 13
Dependent Claim
22 words
A pressure switch according to claim 4, wherein the switching diaphragm has an accumulation of mass distributed uniformly over the circumference thereof.
Claim 14
Dependent Claim
38 words
A pressure switch according to claim 1, wherein the switching diaphragm has an accumulation of mass which consists of a thickened wall of the switching diaphragm which thickness is set to produce a desired vehicle speed-tire pressure relationship.
Claim 15
Dependent Claim
38 words
A pressure switch according to claim 2, wherein the switching diaphragm has an accumulation of mass which consists of a thickened wall of the switching diaphragm which thickness is set to produce a desired vehicle speed-tire pressure relationship.
Claim 16
Dependent Claim
38 words
A pressure switch according to claim 3, wherein the switching diaphragm has an accumulation of mass which consists of a thickened wall of the switching diaphragm which thickness is set to produce a desired vehicle speed-tire pressure relationship.
Claim 17
Dependent Claim
38 words
A pressure switch according to claim 4, wherein the switching diaphragm has an accumulation of mass which consists of a thickened wall of the switching diaphragm which thickness is set to produce a desired vehicle speed-tire pressure relationship.
Claim 18
Dependent Claim
38 words
A pressure switch according to claim 1, wherein the switching diaphragm has an accumulation of mass provided by a centrically arranged sleeve which is connected with the switching diaphragm and surrounds a free end of the contact pin.
Claim 19
Dependent Claim
38 words
A pressure switch according to claim 2, wherein the switching diaphragm has an accumulation of mass provided by a centrically arranged sleeve which is connected with the switching diaphragm and surrounds a free end of the contact pin.
Claim 20
Dependent Claim
38 words
A pressure switch according to claim 3, wherein the switching diaphragm has an accumulation of mass provided by a centrically arranged sleeve which is connected with the switching diaphragm and surrounds a free end of the contact pin.
Claim 21
Dependent Claim
38 words
A pressure switch according to claim 4, wherein the switching diaphragm has an accumulation of mass provided by a centrically arranged sleeve which is connected with the switching diaphragm and surrounds a free end of the contact pin.
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) | 1993-01-15 | 1993-07-17 | 1994-01-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-01-15 | 1997-07-17 | 1998-01-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-01-15 | 2001-07-17 | 2002-01-16 | $7700.00 | Window Closed / Lapsed |