Patent US4979931A successfully refreshed from Google Patents.
US4979931A
Expired / Lapsed
US
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Differential gear and control system for motor vehicles having a single driven axle and at least one undriven axle
Assignee: Steyr Daimler Puch AG
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Filing: 1989-04-12
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Granted: 1990-12-25
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Expires: 2009-04-12
Abstract
Abstract A differential gear and control system for motor vehicles having a single driven axle and at least one undriven axle comprises a differential gear and a differential lock, which is adapted to be controlled in dependence on the speed of travel of the vehicle. In order to increase the traction when the vehicle is started whereas the handling of the vehicle should not adversely be affected by a locking of the differential gear, the differential lock is adapted to be controlled so that it exerts on the differential gear a restraining torque which decreases as the speed of travel of the vehicle increases from zero to a predetermined speed of travel.
Inventors
- 👤 Otwin Fleischmann
- 👤 Hans D. Sommer
- 👤 Erich Erhart
- 👤 Johann Koch
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 10:17
CPC Classifications
B; B60; B60K; B60K23/00; B60K23/04
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
117 words
A differential gear and control system for a motor vehicle having a single driven axle and at least one undriven axle, comprising a differential gear for said driven axle, a differential lock which exerts a restraining torque on said differential gear, and control means for detecting a speed of travel of the vehicle and for controlling the restraining torque exerted by said differential lock on said differential gear so that said restraining torque is at a maximum value when said vehicle is at a standstill, and so that said restraining torque gradually and continuously decreases from said maximum value to a minimum value as said speed of travel increases from standstill to a predetermined speed of travel.
Claim 2
Dependent Claim
117 words
A differential gear and control system for a motor vehicle having a single driven axle and at least one undriven axle, comprising a differential gear for said driven axle, a differential lock which exerts a restraining torque on said differential gear, and control means for detecting a speed of travel of the vehicle and for controlling the restraining torque exerted by said differential lock on said differential gear so that said restraining torque is at a maximum value when said vehicle is at a standstill, and so that said restraining torque gradually and continuously decreases from said maximum value to a minimum value as said speed of travel increases from standstill to a predetermined speed of travel.
Claim 3
Dependent Claim
19 words
The differential gear and control system of claim 1 wherein said minimum value of said restraining torque is zero.
Claim 4
Dependent Claim
46 words
The differential gear and control system of claim 1 wherein said minimum value of said restraining torque is greater than zero, said differential lock exerting said minimum value restraining torque when said speed of travel is equal to or greater than said predetermined speed of travel.
Claim 5
Dependent Claim
18 words
The differential gear and control system of claim 1 wherein said single driven axle is a front axle.
Claim 6
Dependent Claim
35 words
The differential gear and control system of claim 1 wherein said motor vehicle is provided with braking means, further comprising means for disabling said differential lock in response to an application of said braking means.
Claim 7
Dependent Claim
141 words
The differential gear and control system of claim 1 wherein said differential lock comprises a non-positive clutch which exerts said restraining torque on said differential gear, and said control means comprises a sensor for generating output pulse signals representing said speed of travel, and a clutch actuator for actuating said clutch in an engaging and in a disengaging sense in dependence on said output pulse signals, said differential gear and control system further comprising vacuum-applying means connected to said clutch actuator for applying a vacuum to said clutch actuator, said clutch actuator being operable to actuate said clutch in an engaging sense and in a disengaging sense in dependence on the pressure applied to said clutch actuator, and a pressure regulator connected to said vacuumapplying means for controlling the pressure applied to said actuator in dependence on said output pulse signals.--
Claim 8
Dependent Claim
18 words
The differential gear and control system of claim 6 wherein said non-positive clutch comprises a multiple disk clutch.
Claim 9
Dependent Claim
34 words
The differential gear and control system of claim 6 wherein said sensor is operative to detect a rotational speed of said at least one undriven axle as a measure of said speed of travel.
Claim 10
Dependent Claim
27 words
The differential gear and control system of claim 6, wherein said sensor is operative to generate output pulse signals at a frequency representing said speed of travel.
Claim 11
Dependent Claim
54 words
The differential gear and control system of claim 6, wherein said clutch actuator comprises a diaphragm in a chamber, which communicates with said vacuum-applying means and a linkage connecting said diaphragm to said clutch, and said pressure regulator is operative to control the pressure in said chamber in dependence on said output pulse signal.
Claim 12
Dependent Claim
17 words
The differential gear and control system of claim 10, wherein said vacuum-applying means comprises a vacuum pump.
Claim 13
Dependent Claim
33 words
The differential gear and control system of claim 10, wherein said pressure regulator comprises valve means for admitting atmospheric air in pulses to said clutch actuator in dependence on said output pulse signals.
Claim 14
Dependent Claim
73 words
The differential gear and control system of claim 12, wherein said clutch actuator is operative to actuate said clutch in an engaging sense to an extent depending on the vacuum in said chamber, said sensor is operative to generate output pulse signals at a frequency representing said speed of travel, and said valve means is operative in pulses at the frequency of said output pulse signals to admit atmospheric air to said chamber.
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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) | 1993-12-24 | 1994-06-25 | 1994-12-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-12-24 | 1998-06-25 | 1998-12-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-12-24 | 2002-06-25 | 2002-12-25 | $7700.00 | Window Closed / Lapsed |