US3722960A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Braking system for automotive vehicles with means for preventing the locking of wheels during braking
Assignee: Robert Bosch GmbH
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Filing: 1970-08-27
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Granted: 1973-03-27
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Expires: 1990-08-27
Abstract
Abstract A braking system for the wheels of an automotive vehicle wherein the master cylinder is connected with the wheel cylinders by brake lines and can supply to the wheel cylinders a braking medium under such pressure that the wheels are locked and skid along the road surface. The braking system further includes devices which prevent prolonged locking of wheels in response to excessive pressurization of the braking medium, and each such device includes a shutoff valve which is provided in the respective brake line, a control piston which normally holds the shutoff valve in open position under the action of a pressurized fluid, and a safety plunger which is normally retracted to stress a spring and is displaced by such spring in response to a predetermined drop in the fluid pressure whereby the plunger maintains the shutoff valve in open position by way of the control piston. The latter permits the shutoff valve to close when a sensor detects that the corresponding wheel is locked in response to excessive pressure of braking medium in the wheel cylinder; at the same time, the control piston increases the volume of a cylinder chamber which receives some braking medium to thus effect a reduction of pressure in the wheel cylinder and the termination of locking action.
Inventors
- 👤 Lowis Of Menar A Von
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 14:57
CPC Classifications
B; B60; B60T; B60T8/00; B60T8/32; B60T8/34; B60T8/42; B60T8/4208; B60T8/4225; B60T8/4233
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
299 words
In a braking system for the wheels of automotive vehicles, a combination comprising a wheel cylinder; means including a brake line for supplying to said cylinder a braking medium at a pressure which suffices to cause locking of the corresponding wheel; and a device for preventing prolonged locking of the wheel, said device comprising a shutoff valve in said brake line, a control piston normally assuming an operative position in which said piston opens said valve, one end of said piston being subjected to the pressure of braking mediUm in said line whereby the braking medium tends to move said piston to an inoperative position in which the piston permits said valve to close with attendant reduction of the pressure of braking medium in said cylinder, a source of pressurized fluid, a safety plunger movable between a first position in which said plunger permits said piston to assume said inoperative position and a second position in which said plunger maintains said piston in said operative position, means for constantly biasing said plunger to said second position, cylinder means provided for said plunger and permanently connected with said source so that the pressurized fluid normally maintains said plunger in said first position as long as the pressure of said fluid exceeds a predetermined minimum value, means for connecting the other end of said piston with said source so that the other end of said piston is subjected to fluid pressure which at least approximates the pressure of fluid action upon said plunger, and regulating valve means actuatable to seal off said source from said other end of said piston in response to locking of the corresponding wheel whereby the pressure of braking medium acting against said one end of said piston suffices to move said piston to said inoperative position.
Claim 2
Dependent Claim
299 words
In a braking system for the wheels of automotive vehicles, a combination comprising a wheel cylinder; means including a brake line for supplying to said cylinder a braking medium at a pressure which suffices to cause locking of the corresponding wheel; and a device for preventing prolonged locking of the wheel, said device comprising a shutoff valve in said brake line, a control piston normally assuming an operative position in which said piston opens said valve, one end of said piston being subjected to the pressure of braking mediUm in said line whereby the braking medium tends to move said piston to an inoperative position in which the piston permits said valve to close with attendant reduction of the pressure of braking medium in said cylinder, a source of pressurized fluid, a safety plunger movable between a first position in which said plunger permits said piston to assume said inoperative position and a second position in which said plunger maintains said piston in said operative position, means for constantly biasing said plunger to said second position, cylinder means provided for said plunger and permanently connected with said source so that the pressurized fluid normally maintains said plunger in said first position as long as the pressure of said fluid exceeds a predetermined minimum value, means for connecting the other end of said piston with said source so that the other end of said piston is subjected to fluid pressure which at least approximates the pressure of fluid action upon said plunger, and regulating valve means actuatable to seal off said source from said other end of said piston in response to locking of the corresponding wheel whereby the pressure of braking medium acting against said one end of said piston suffices to move said piston to said inoperative position.
Claim 3
Dependent Claim
24 words
A combination as defined in claim 1, wherein said control piston is a multi-stage piston one stage of which is subjected to atmospheric pressure.
Claim 4
Dependent Claim
40 words
A combination as defined in claim 1, further comprising an intermediate piston interposed between said control piston and said safety plunger to move said control piston to operative position in response to movement of said plunger to said second position.
Claim 5
Dependent Claim
61 words
A combination as defined in claim 3, wherein said regulating valve means is arranged to admit pressurized fluid from said source against one end of said intermediate piston in response to locking of the wheel which is associated with said wheel cylinder whereby such fluid tends to move said intermediate piston in a direction to permit closing of said shutoff valve.
Claim 6
Dependent Claim
21 words
A combination as defined in claim 4, wherein said one end of said intermediate piston is normally subjected to atmospheric pressure.
Claim 7
Dependent Claim
32 words
A combination as defined in claim 1, wherein said fluid is a hydraulic fluid and said source comprises pump means and supply conduit means connecting said pump means with said cylinder means.
Claim 8
Dependent Claim
27 words
A combination as defined in claim 1, wherein said biasing means comprises a helical spring which is normally maintained by said control plunger in fully stressed condition.
Claim 9
Dependent Claim
43 words
A combination as defined in claim 1, wherein said source comprises a supply conduit connected with said cylinder means and further comprising detector means responsive to locking of the wheel which is associated with said wheel cylinder to actuate said regulating valve means.
Claim 10
Dependent Claim
28 words
A combination as defined in claim 1, wherein said cylinder means constitutes a housing for said shutoff valve, said control piston, said safety plunger and said biasing means.
Claim 11
Dependent Claim
27 words
A combination as defined in claim 1, wherein the normal pressure of said fluid at least equals the maximum pressure of braking medium in said brake line.
Claim 12
Dependent Claim
27 words
A combination as defined in claim 1, wherein the normal pressure of said fluid is less than the maximum pressure of braking medium in said brake line.
Claim 13
Dependent Claim
231 words
A combination as defined in claim 1, wherein said cylinder means comprises a first chamber adjacent to said other end of said piston, a second chamber, and an apertured partition between said first and second chambers, said plunger being reciprocable in said second chamber and having a piston rod sealingly extending through the aperture of said partition, said piston rod being spaced apart from said piston in the first position of said plunger and engaging said piston in the second position of said plunger, said source comprising a supply conduit and a return conduit, said regulating valve means being installed in said supply conduit and having A valve member normally assuming a first position in which said supply is connected with said first and second chambers to maintain said piston in said operative position and to simultaneously maintain said plunger in said first position, said valve member being movable to a second position in which said second chamber remains connected to said supply conduit and the first chamber is connected with said return conduit so that, when the fluid pressure in said supply conduit drops below said minimum value, said plunger assumes said second position under the action of said biasing means, said device further comprising detector means cooperating with said regulating valve means to move said valve member to said second position in response to locking of the corresponding wheel.
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) | 1976-03-26 | 1976-09-25 | 1977-03-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-03-26 | 1980-09-25 | 1981-03-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-03-26 | 1984-09-25 | 1985-03-27 | $7700.00 | Window Closed / Lapsed |