Patent US3767272A successfully refreshed from Google Patents.
US3767272A
Expired / Lapsed
US
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Hydraulic brake system with anti-locking control
Assignee: Robert Bosch GmbH
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Filing: 1971-09-23
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Granted: 1973-10-23
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Expires: 1991-09-23
Abstract
Abstract An improved hydraulic brake system of the type including an anti-locking control for preventing the locking of a wheel or wheels during a braking action, and shutoff valves in the lines which connect the pressure source, i.e., the master cylinder, to the wheel brake cylinders. At least one volume monitor, (leak detector) is provided for determining the volume of the pressure medium flowing from the pressure source to the respective wheel brake cylinder and for emitting an electrical signal, which is used to close the associated shut off valve, whenever a certain threshold volume has been exceeded indicating a leak in the associated brake line. Various specific arrangements for the volume monitor control, both in single circuit and dual circuit brake systems and a preferred arrangement for the brake circuit distribution for a front wheel drive automobile are disclosed.
Inventors
- 👤 H Leiber
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 17:22
CPC Classifications
B; B60; B60T; B60T17/00; B60T17/18; B60T17/22; B60T11/00; B60T11/10; B60T11/28; B60T11/32; B60T11/323; B60T8/00; B60T8/17; B60T8/176; B60T8/1761; B60T8/17613; B60T8/32; B60T8/34; B60T8/42; B60T8/4275; B60T8/44; B60T8/88; B60T8/92; B60T8/96; B60T2270/00; B60T2270/40; B60T2270/403; Y; Y10; Y10T; Y10T137/00; Y10T137/7722; Y10T137/7758; Y10T137/7759
Claims Analysis
Total Claims: 31
Claim 1
Independent Claim
195 words
In a hydraulic brake system for a vehicle, said brake system including an anti-locking control system for controlling the pressure applied to the vehicle wheels to prevent locking thereof, said anti-locking control system being of the type wherein shutoff valves are connected in the brake lines connecting the pressure source to the wheel brake cylinders, the improvement comprising: at least one volume monitoring means connected in said hydraulic brake system for detecting the volume of the pressure medium flowing from the pressure source to the wheel brake cylinder and for emitting an electrical signal when a predetermined threshold volume of said pressure medium has been exceeded, indicating that a leak exists in the associated brake channel; circuit means responsive to said electrical signal for closing the shutoff valve associated with the brake line being monitored by said volume monitoring means, said circuit means including a memory means for storing said electrical signal until the current supply thereto is shut off; and means for providing a warning indication connected to the output of said memory means and responsive to said electrical signal, whereby said warning indication is also maintained until said current supply is shut off.
Claim 2
Dependent Claim
195 words
In a hydraulic brake system for a vehicle, said brake system including an anti-locking control system for controlling the pressure applied to the vehicle wheels to prevent locking thereof, said anti-locking control system being of the type wherein shutoff valves are connected in the brake lines connecting the pressure source to the wheel brake cylinders, the improvement comprising: at least one volume monitoring means connected in said hydraulic brake system for detecting the volume of the pressure medium flowing from the pressure source to the wheel brake cylinder and for emitting an electrical signal when a predetermined threshold volume of said pressure medium has been exceeded, indicating that a leak exists in the associated brake channel; circuit means responsive to said electrical signal for closing the shutoff valve associated with the brake line being monitored by said volume monitoring means, said circuit means including a memory means for storing said electrical signal until the current supply thereto is shut off; and means for providing a warning indication connected to the output of said memory means and responsive to said electrical signal, whereby said warning indication is also maintained until said current supply is shut off.
Claim 3
Dependent Claim
91 words
A hydraulic brake system as defined in claim 1 wherein said anti-locking control system for preventing locking of the vehicle wheels is the type which provides a pressure reduction at a particular wheel cylinder upon the detection of a locking condition by permitting a volume of pressure medium to flow into a return line to the pressure source; and wherein said circuit means includes logic circuit means for permitting said electrical signal to close said shutoff valve only when said anti-locking control system is not functioning to control the braking action.
Claim 4
Dependent Claim
124 words
A hydraulic brake system as defined in claim 1 wherein said volume monitoring means comprises: a cylinder having a piston mounted therein, said piston dividing the interior of said cylinder into two chambers, one end of said cylinder, and hence one of said chambers, being connected to the outlet of the associated shutoff valve and the other end of said cylinder, and hence the other of said chambers, being connected to the brake line leading to the associated wheel cylinder; an electrical switch mounted adjacent said cylinder at a position along its length corresponding to said predetermined threshold volume; and means on said piston for actuating said electrical switch when said piston has traveled in said cylinder to a position adjacent said electrical switch.
Claim 5
Dependent Claim
80 words
A hydraulic brake system as defined in claim 3 wherein: said piston includes a pair of longitudinal channels which conneCt said two chambers, one of said channels including a check valve which opens in the direction from the wheel brake cylinder to the shutoff valve, the other of said channels containing a fine nozzle; and a spring mounted within said cylinder for normally urging said piston against the end of said cylinder connected to the output of said shutoff valve.
Claim 6
Dependent Claim
59 words
A hydraulic brake system as defined in claim 3 wherein said means on said piston for actuating said electrical switch comprises a permanent magnet; and wherein said electrical switch comprises a magnetic field sensitive switch which is arranged adjacent said cylinder so that it is actuated by the magnetic field of said magnet when said piston is adjacent thereto.
Claim 7
Dependent Claim
61 words
A hydraulic brake system as defined in claim 3 wherein the inner wall of said cylinder is provided with a longitudinal channel which is so arranged and dimensioned that a connection is produced between said two chambers which bypasses said piston when said piston is adjacent the end of said cylinder connected to the brake line leading to the wheel cylinder.
Claim 8
Dependent Claim
180 words
A hydraulic brake system as defined in claim 1 wherein said volume monitoring means comprises: at least two cylinders each having a movable piston mounted therein which divides the interior of the respective cylinder into two chambers, each of said cylinders being connected in the brake line leading to a different wheel cylinder, with one end thereof, and hence one of said chambers, being connected to the outlet of the shutoff valve for the associated brake line and the other end thereof, and hence the other of said chambers, being connected to the inlet of the associated brake cylinder; means for detecting the position of each of said pistons; a separate output line associated with each of said pistons; and means for comparing the positions of said pistons and for generating said electrical signal on the one of said output lines associated with the leading piston whenever the difference between the positions of the pistons reaches a predetermined value; and wherein said circuit means is responsive to said electrical signal to close the shutoff valve associated with said leading piston.
Claim 9
Dependent Claim
87 words
A hydraulic brake system as defined in claim 7 wherein: each of said pistons includes a pair of longitudinal channels which connect said two chambers, one of said channels including a check valve which opens in the direction from the wheel brake cylinder to the shutoff valve, the other of said channels containing a fine nozzle; and a spring is mounted within each of said cylinder for normally urging the associated said piston against the end of said cylinder connected to the output of said shutoff valve.
Claim 10
Dependent Claim
57 words
A hydraulic brake system as defined in claim 7 wherein said means for detecting the position of each of said pistons comprises a resistor whose resistance value varies with the position of the associated piston within the cylinder; and wherein said comparing and generating means includes a bridge circuit having said resistors connected in different arms thereof.
Claim 11
Dependent Claim
91 words
A hydraulic brake system as defined in claim 7 wherein said anti-locking control system for preventing locking of the vehicle wheels is the type which provides a pressure reduction at a particular wheel cylinder upon the detection of a locking condition by permitting a volume of pressure medium to flow into a return line to the pressure source; and wherein said circuit means includes logic circuit means for permitting said electrical signal to close said shutoff valve only when said anti-locking control system is not functioning to control the braking action.
Claim 12
Dependent Claim
19 words
A hydraulic brake system as defined in claim 1 wherein said brake system is a dual circuit brake system.
Claim 13
Dependent Claim
82 words
A hydraulic brake system as defined in claim 11 wherein: wheel cylinders of two wheels are included in each circuit; each wheel cylinder is separately controlled by said anti-locking control system by means of a Separate normally open inlet or shutoff valve connected in the associated brake line and a normally closed outlet valve connected to the brake line at the outlet of the inlet valve; and wherein one of said volume monitoring means is connected in each of said brake lines.
Claim 14
Dependent Claim
134 words
A hydraulic brake system as defined in claim 11 wherein said pressure source for said brake system is a dual circuit master cylinder having two parallel cylinders each containing a piston; wherein said volume monitoring means comprises: an axially movable rod connected to the brake pedal of said vehicle; a swingletree mounted on said rod with the actuating arm for each of said pistons being connected to the end of a different one of the arms of said swingletree; electrical switch means rigidly mounted on said rod and positioned to respond to and produce said electrical signal upon a given rotational displacement of an end of said swingletree; and wherein said circuit means is responsive to said electrical signal to close at least one of the shutoff valves incorporated in the respective brake circuit.
Claim 15
Dependent Claim
27 words
A hydraulic brake system as defined in claim 13 wherein said switch means includes a pair of electrical switches, one positioned adjacent each end of said swingletree.
Claim 16
Dependent Claim
42 words
A hydraulic brake system as defined in claim 14 wherein said circuit means is responsive to the output signal from one of said electrical switches to close all of the shutoff valves incorporated in the brake lines of the associated brake circuit.
Claim 17
Dependent Claim
109 words
A hydraulic brake system as defined in claim 13 wherein at least one brake circuit includes a plurality of shutoff valves each connected in the brake line to a different wheel cylinder; wherein said switch means associated with said at least one brake circuit produces an electrical output signal related to the degree of angular displacement of the arms of said swingletree; and wherein said circuit means includes means responsive to said electrical output signal for closing the shutoff valves associated with said at least one brake circuit in succession, with only one shutoff valve being closed at any one time, until no further displacement of said swingletree occurs
Claim 18
Dependent Claim
109 words
A hydraulic brake system as defined in claim 16 wherein said switch means produces a first electrical output signal when said swingletree is displaced by a first angular value and a second electrical output signal when said swingletree is displaced by a second further angular value; and wherein said circuit means is responsive to said first electrical output signal to close a first of the shutoff valves associated with said at least one brake circuit, and is responsive to said second electrical output signal to close a second of the shutoff valves associated with said at least one brake circuit and to open said first of the shutoff valves.
Claim 19
Dependent Claim
65 words
A hydraulic brake system as defined in claim 11 wherein one brake circuit of said dual circuit brake system includes only the brake of one front wheel and the second brake circuit includes the brakes of the remaining wheels; and wherein said volume monitoring means and a shutoff valve are connected in at least one of the pressure medium lines of one of said circuits.
Claim 20
Dependent Claim
45 words
A hydraulic brake system as defined in claim 18 wherein said volume monitoring means and the associated shutoff valve controlled thereby are disposed in the pressure medium line leading to the front wheel which is included in the brake circuit including the two rear wheels.
Claim 21
Dependent Claim
61 words
A hydraulic brake system as defined in claim 18 wherein said anti-locking control system separately controls the brake pressure at each of the rear wheels; and wherein a volume monitoring means is connected in at least one pressure medium channel leading to the rear wheel brakes, said volume monitoring means controlling the shutoff valve disposed in said at least one channel.
Claim 22
Dependent Claim
26 words
A hydraulic brake system as defined in claim 18 wherein said anti-locking control system provides a combined control of the brake pressUre at the rear wheels.
Claim 23
Dependent Claim
39 words
A hydraulic brake system as defined in claim 21 wherein said volume monitoring means is connected in the common pressure medium channel leading to the rear wheel brakes, said monitor controlling the shutoff valve disposed in said common channel.
Claim 24
Dependent Claim
49 words
A hydraulic pressure system as defined in claim 22 wherein said anti-locking control system controls the brake pressure by means of a normally open inlet valve and a normally closed outlet valve per controlled channel, and wherein said volume monitoring means controls said inlet valve as the shutoff valve.
Claim 25
Dependent Claim
45 words
A hydraulic brake system as defined in claim 22 wherein said anti-locking control system controls the brake pressure by means of a three-way valve connected in the channel to be controlled; and wherein said volume monitoring means controls said three-way valve to block the channel.
Claim 26
Dependent Claim
33 words
A hydraulic brake system as defined in claim 21 wherein said anti-locking control system controls said jointly controlled rear wheels based on the acceleration and/or rotational wheel speed signals derived from said wheels.
Claim 27
Dependent Claim
50 words
A hydraulic brake system as defined in claim 25 wherein for a joint control of the brake pressure at the rear wheels said anti-locking control system includes means for controlling the rear wheel brakes to prevent locking in accordance with the rotational behavior of the faster rotating wheel (select high).
Claim 28
Dependent Claim
50 words
A hydraulic brake system as defined in claim 25 wherein for a joint control of the brake pressure at the rear wheels, said anti-locking control system includes means for controlling the rear wheel brakes to prevent locking in accordance with the rotational behavior of the slower rotating wheel (select low).
Claim 29
Dependent Claim
86 words
A hydraulic brake system as defined in claim 26 wherein said means for controlling the rear wheels normally controls same in accordance with the rotational behavior of the faster rotating wheel; wherein means are provided for detecting the transverse acceleration of the vehicle, and wherein said means for controlling further includes means responsive to the occurence of a given transverse acceleration for switching the control to a state in which it controls the rear wheels in accordance with the rotational behavior of the slower rotating wheel.
Claim 30
Dependent Claim
47 words
A hydraulic brake system as defined in claim 25 wherein said anti-locking control system includes means for forming a reference value from the signals derived from the rear wheels, and for using said reference value to control the brake pressure at the front wheels of said vehicle.
Claim 31
Dependent Claim
52 words
A hydraulic brake system as defined in claim 25 wherein said anti-locking control system includes means for forming a reference value from the signals derived from the rear wheels and from the front wheels and for using said reference value to control the brake pressure at the front wheels of said vehicle.
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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) | 1976-10-22 | 1977-04-23 | 1977-10-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-10-22 | 1981-04-23 | 1981-10-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-10-22 | 1985-04-23 | 1985-10-23 | $7700.00 | Window Closed / Lapsed |