Patent US4545240A successfully refreshed from Google Patents.
US4545240A
Expired / Lapsed
US
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Apparatus for ascertaining the adhesion factor of a road surface
Assignee: Robert Bosch GmbH
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Filing: 1982-01-07
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Granted: 1985-10-08
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Expires: 2002-01-07
Abstract
Abstract To determine aquaplaning or, in general, the adhesion factor of tires of a vehicle on a road surface, test braking pressure (p 1 , p 2 , p 3 , p 4 ) is applied to a wheel or wheels, preferably the rolling wheels, of a vehicle. Wheel slip, that is, difference between deceleration of a wheel and deceleration of the vehicle is determined upon application of the test pressure, and an output signal is generated, indicated of wheel slippage, if a given wheel slip occurs at a test pressure below that which would be expected on a gripping or rough surface, so that wheel slippage with respect to the road surface is determined early. The test braking cycle can be initiated manually (switch 12) by an operator, from time to time, and, preferably, can be commanded automatically by an antibrake lock system (ABS, 10) by applying a braking pressure well below that required, for example, for vehicle operation under traffic conditions, and merely to determine wheel slippage.
Inventors
- 👤 Heinz Leiber
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 17:16
CPC Classifications
B; B60; B60T; B60T8/00; B60T8/17; B60T8/172; B60T2210/00; B60T2210/10; B60T2210/12; B60T2210/13; Y; Y10; Y10S; Y10S303/00; Y10S303/02; Y10S303/03; Y10S303/04
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
155 words
Apparatus to determine the adhesion factor of wheels on a vehicle on a road surface, wherein the vehicle has power assisted brakes (14, 15); means (16, 17; 20, 21, 22; 13) for applying braking pressure to the brakes; and means (10, 11) for determining slip (S) of a wheel or wheels of the vehicle with respect to the road surface, comprising, in accordance with the invention, means (12) for applying an increasing test braking pressure (p 1 , p 2 , p 3 , p 4 ) to a wheel or wheels of the vehicle; slip determination means (10) responsive to peripheral wheel speed and to vehicle speed and determining wheel slip upon application of the test pressure to the brakes, and generating an output signal (23) if, when the slip exceeds a given value upon application of test pressure to the brakes of the vehicle, the test pressure has not exceeded a predetermined level.
Claim 2
Dependent Claim
155 words
Apparatus to determine the adhesion factor of wheels on a vehicle on a road surface, wherein the vehicle has power assisted brakes (14, 15); means (16, 17; 20, 21, 22; 13) for applying braking pressure to the brakes; and means (10, 11) for determining slip (S) of a wheel or wheels of the vehicle with respect to the road surface, comprising, in accordance with the invention, means (12) for applying an increasing test braking pressure (p 1 , p 2 , p 3 , p 4 ) to a wheel or wheels of the vehicle; slip determination means (10) responsive to peripheral wheel speed and to vehicle speed and determining wheel slip upon application of the test pressure to the brakes, and generating an output signal (23) if, when the slip exceeds a given value upon application of test pressure to the brakes of the vehicle, the test pressure has not exceeded a predetermined level.
Claim 3
Dependent Claim
36 words
Apparatus according to claim 1, wherein the means for applying braking pressure includes a hydraulic assembly; and said test pressure is applied gradually in increasing braking level by the hydraulic assembly to the brakes (14, 15).
Claim 4
Dependent Claim
18 words
Apparatus according to claim 2, wherein the hydraulic assembly applies the increasing brake pressure at a controllable rate.
Claim 5
Dependent Claim
29 words
Apparatus according to claim 2, including a timing stage (T) connected to an ABS (10) to control the time duration of application of the test pressure to the brakes.
Claim 6
Dependent Claim
48 words
Apparatus according to claim 1, wherein the means for applying braking pressure comprises operator controlled brake application means (16, 17); and a pressure transducer (18) is provided furnishing an output signal when the pressure on the brakes reaches a predetermined level corresponding to a maximum test pressure level.
Claim 7
Dependent Claim
61 words
Apparatus according to claim 1, including an antibrake lock or antiskid system (ABS) (10) connected to and controlling application of braking pressure to the vehicle brakes (14, 15), wherein the slip determination means form part of said ABS (10) and controls the test braking pressure to decrease if the slip determined by the slip determination means exceeds said predetermined threshold level.
Claim 8
Dependent Claim
28 words
Apparatus according to claim 2, wherein the brakes to which the test braking pressure is applied are the brakes associated with the rolling wheels of the vehicle only.
Claim 9
Dependent Claim
42 words
Apparatus according to claim 1, wherein the vehicle includes a drive engine; and further comprising means (10; 24, 24a) connected to the drive engine to increase torque on the engine during application of the braking pressure by the braking pressure application means.
Claim 10
Dependent Claim
83 words
Apparatus according to claim 6, including switching means (12) connected to and controlling the ABS (10) to apply a test braking pressure to a wheel or wheels of the vehicle, and to discontinue application of test braking pressure if (a) the slip determination means determines that the slip has exceeded the predetermined threshold level; or at least one of: (b-1) a predetermined test pressure level (p 4max ) has been reached; (b-2) the vehicle has decelerated by a pedetermined amount (dv/dt max ).
Claim 11
Dependent Claim
32 words
Apparatus according to claim 1, wherein the slip determination means includes braking pressure sensing means monitoring the braking pressure and providing a signal when the test pressure has exceeded a predetermined level.
Claim 12
Dependent Claim
33 words
Apparatus according to claim 1, wherein the slip determination means includes means (10) for sensing a change in proportionality of wheel speed and vehicle speed upon application of test pressure to the brakes.
Claim 13
Dependent Claim
157 words
Apparatus to determine the adhesion factor of wheels on a vehicle on a road surface, wherein the vehicle has power assisted brakes (14, 15); means (16, 17; 20, 21, 22; 13) for applying braking pressure to the brakes; and means (10, 11) for determining slip (S) of a wheel or wheels of the vehicle with respect to the road surface, comprising, in accordance with the invention, means (12) for applying an increasing test braking pressure (p 1 , p 2 , p 3 , p 4 ) to a wheel or wheels of the vehicle; slip determination means (10) responsive to peripheral wheel speed and to vehicle speed and determining wheel slip upon application of the test pressure to the brakes, and generating an output signal (23) if, when the slip exceeds a given value upon application of test pressure to the brakes of the vehicle, the deceleration of the vehicle has not exceeded a predetermined level.
Claim 14
Dependent Claim
157 words
Apparatus to determine the adhesion factor of wheels on a vehicle on a road surface, wherein the vehicle has power assisted brakes (14, 15); means (16, 17; 20, 21, 22; 13) for applying braking pressure to the brakes; and means (10, 11) for determining slip (S) of a wheel or wheels of the vehicle with respect to the road surface, comprising, in accordance with the invention, means (12) for applying an increasing test braking pressure (p 1 , p 2 , p 3 , p 4 ) to a wheel or wheels of the vehicle; slip determination means (10) responsive to peripheral wheel speed and to vehicle speed and determining wheel slip upon application of the test pressure to the brakes, and generating an output signal (23) if, when the slip exceeds a given value upon application of test pressure to the brakes of the vehicle, the deceleration of the vehicle has not exceeded a predetermined level.
Claim 15
Dependent Claim
36 words
Apparatus according to claim 12, wherein the means for applying braking pressure includes a hydraulic assembly; and said test pressure is applied gradually in increasing braking level by the hydraulic assembly to the brakes (14, 15).
Claim 16
Dependent Claim
18 words
Apparatus according to claim 13, wherein the hydraulic assembly applies the increasing brake pressure at a controllable rate.
Claim 17
Dependent Claim
29 words
Apparatus according to claim 13, including a timing stage (T) connected to an ABS (10) to control the time duration of application of the test pressure to the brakes.
Claim 18
Dependent Claim
48 words
Apparatus according to claim 12, wherein the means for applying braking pressure comprises operator controlled brake application means (16, 17); and a pressure transducer (18) is provided furnishing an output signal when the pressure on the brakes reaches a predetermined level corresponding to a maximum test pressure level.
Claim 19
Dependent Claim
60 words
Apparatus according to claim 12, including an antibrake lock or antiskid system (ABS) (10) connected to and controlling application of braking pressure to the vehicle brakes (14, 15), wherein the slip determination means form part of said ABS (10) and controls the test braking pressure to decrease if the slip determined by the slip determination means exceeds said given value.
Claim 20
Dependent Claim
28 words
Apparatus according to claim 13, wherein the brakes to which the test braking pressure is applied are the brakes associated with the rolling wheels of the vehicle only.
Claim 21
Dependent Claim
42 words
Apparatus according to claim 12, wherein the vehicle includes a drive engine; and further comprising means (10; 24, 24a) connected to the drive engine to increase torque on the engine during application of the braking pressure by the braking pressure application means.
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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) | 1988-10-07 | 1989-04-08 | 1989-10-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-10-07 | 1993-04-08 | 1993-10-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-10-07 | 1997-04-08 | 1997-10-08 | $7700.00 | Window Closed / Lapsed |