US3852962A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Master cylinder partial system displacement modifier
Assignee: Motors Liquidation Co
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Filing: 1973-03-26
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Granted: 1974-12-10
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Expires: 1993-03-26
Abstract
Abstract A brake system in which a dual master cylinder is connected to actuate dual braking circuits. A shuttle piston of the type utilized to actuate a brake pressure loss warning switch also operates to control a master cylinder displacement modifier, the shuttle piston being a part of the modifier. The opposed chambers in the bore containing the shuttle piston are connected by a passage having a check valve therein, the passage being closed upon brake pressure loss in one of the brake circuits and also being closed when both brake circuits are at substantially the same pressure. When brake pressure loss occurs in the other brake circuit, the port to that circuit from the modifier is closed and pressurized fluid from both master cylinder pressurizing chambers passes through the above mentioned connecting passage and check valve to the one brake circuit. This permits the substantially full displacement of both master cylinder chambers to be used to actuate the one brake circuit upon pressure loss in the other brake circuit.
Inventors
- 👤 E Warwick
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 12:47
CPC Classifications
B; B60; B60T; B60T11/00; B60T11/10; B60T11/24; B60T17/00; B60T17/18; B60T17/22; B60T17/226
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
382 words
For use in a brake system having a dual pressurizing chamber master cylinder and dual pressure circuits normally pressurized thereby upon brake actuation, a master cylinder displacement modifier comprising: a housing having a bore therein defined by a side wall and first and second end walls; a reciprocable piston sealingly received in said bore to define therewith a first pressure chamber at one bore end and a second pressure chamber at the other bore end, each pressure chamber having a pressure inlet port for receiving pressurized brake fluid from a pressurizing chamber of the master cylinder and a pressure outlet port for delivering pressurized brake fluid to a dual pressure circuit, the forces generated by pressures in said pressure chambers acting in opposite directions on said piston; a recess in said first end wall at said first pressure chamber outlet port, a first plug valve element on said piston positioned to extend into said recess and close said first pressure chamber outlet port upon movement of said piston toward said first pressure chamber outlet port in response to a predetermined minimum pressure differential acting across said piston toward said first end wall; a third port communicating with said first pressure chamber, a fourth port in said second end wall, and a fluid pressure conduit connecting said third and fourth ports; a passage and a valve chamber in said second end wall communicating said second pressure chamber and said fourth port, a check valve in said valve chamber when closed interrupting communication between said valve chamber and said fourth port; a second plug valve element on said piston positioned to extend into said passage in passage sealing relation upon movement of said piston toward said second end wall in response to a predetermined minimum pressure differential acting across said piston toward said second end wall, said second plug valve element being positioned to permit fluid communication between said second pressure chamber and said passage subject to the opening of said check valve, such position of said second plug valve element permitting the use of the master cylinder displacement of both pressurizing chambers thereof for pressurizing the brake circuit connected with the second pressure chamber outlet port when the other brake circuit has lost pressure and said first-mentioned predetermined minimum pressure differential is exceeded.
Claim 2
Dependent Claim
382 words
For use in a brake system having a dual pressurizing chamber master cylinder and dual pressure circuits normally pressurized thereby upon brake actuation, a master cylinder displacement modifier comprising: a housing having a bore therein defined by a side wall and first and second end walls; a reciprocable piston sealingly received in said bore to define therewith a first pressure chamber at one bore end and a second pressure chamber at the other bore end, each pressure chamber having a pressure inlet port for receiving pressurized brake fluid from a pressurizing chamber of the master cylinder and a pressure outlet port for delivering pressurized brake fluid to a dual pressure circuit, the forces generated by pressures in said pressure chambers acting in opposite directions on said piston; a recess in said first end wall at said first pressure chamber outlet port, a first plug valve element on said piston positioned to extend into said recess and close said first pressure chamber outlet port upon movement of said piston toward said first pressure chamber outlet port in response to a predetermined minimum pressure differential acting across said piston toward said first end wall; a third port communicating with said first pressure chamber, a fourth port in said second end wall, and a fluid pressure conduit connecting said third and fourth ports; a passage and a valve chamber in said second end wall communicating said second pressure chamber and said fourth port, a check valve in said valve chamber when closed interrupting communication between said valve chamber and said fourth port; a second plug valve element on said piston positioned to extend into said passage in passage sealing relation upon movement of said piston toward said second end wall in response to a predetermined minimum pressure differential acting across said piston toward said second end wall, said second plug valve element being positioned to permit fluid communication between said second pressure chamber and said passage subject to the opening of said check valve, such position of said second plug valve element permitting the use of the master cylinder displacement of both pressurizing chambers thereof for pressurizing the brake circuit connected with the second pressure chamber outlet port when the other brake circuit has lost pressure and said first-mentioned predetermined minimum pressure differential is exceeded.
Claim 3
Dependent Claim
295 words
In a dual circuit brake system having separate first and second fluid pressure circuits, a fluid displacement modifier including; a housing having a closed end bore therein, a piston reciprocably received in said bore and dividing said bore into first and second pressure chambers respectively located on one side and the other side of said piston, first and second inlet port means respectively in said first and second fluid pressure circuits and respectively communicating with said first and second pressure chambers, first and second outlet port means respectively in said first and second pressure circuits and respectively communicating with said first and second pressure chambers, said piston being slidable in said bore in one direction from a center position to selectively close said first outlet port means on one side of said piston when said piston is moved in said one direction by a force differential of sufficient magnitude, a fluid flow path between said first and second pressure chambers including bypass passage means communicating with said bore through separate bypass port means on each side of said piston with said piston arranged to close the bypass port means on the other side of said piston from said first outlet port means when said piston is moved in said bore in the other direction from said one direction by a force differential of sufficient magnitude, and check valve means in said fluid flow path between said first and second pressure chambers and permitting fluid flow through said fluid flow path only in the direction from said first pressure chamber toward said second pressure chamber, said first inlet port means being in fluid flow communication with said second outlet port means through said fluid flow path while said piston keeps said first outlet port means closed.
Claim 4
Dependent Claim
295 words
In a dual circuit brake system having separate first and second fluid pressure circuits, a fluid displacement modifier including; a housing having a closed end bore therein, a piston reciprocably received in said bore and dividing said bore into first and second pressure chambers respectively located on one side and the other side of said piston, first and second inlet port means respectively in said first and second fluid pressure circuits and respectively communicating with said first and second pressure chambers, first and second outlet port means respectively in said first and second pressure circuits and respectively communicating with said first and second pressure chambers, said piston being slidable in said bore in one direction from a center position to selectively close said first outlet port means on one side of said piston when said piston is moved in said one direction by a force differential of sufficient magnitude, a fluid flow path between said first and second pressure chambers including bypass passage means communicating with said bore through separate bypass port means on each side of said piston with said piston arranged to close the bypass port means on the other side of said piston from said first outlet port means when said piston is moved in said bore in the other direction from said one direction by a force differential of sufficient magnitude, and check valve means in said fluid flow path between said first and second pressure chambers and permitting fluid flow through said fluid flow path only in the direction from said first pressure chamber toward said second pressure chamber, said first inlet port means being in fluid flow communication with said second outlet port means through said fluid flow path while said piston keeps said first outlet port means closed.
Claim 5
Dependent Claim
138 words
For use in a dual circuit brake system, a brake pressure circuit modifier comprising: a first inlet port and a first outlet port adapted to be connected in series flow relation in a first brake pressure circuit, a second inlet port and a second outlet port adapted to be connected in series flow relation in a second brake pressure circuit, and means responsive in one brake system condition to pressure loss only at said first outlet port to close said first outlet port and divert brake pressure from said first inlet port to said second outlet port, so that both of said inlet ports supply brake pressure only to said second outlet port, said means being responsive in another brake system condition to pressure loss only at said second outlet port to severely restrict said second outlet port.
Claim 6
Dependent Claim
138 words
For use in a dual circuit brake system, a brake pressure circuit modifier comprising: a first inlet port and a first outlet port adapted to be connected in series flow relation in a first brake pressure circuit, a second inlet port and a second outlet port adapted to be connected in series flow relation in a second brake pressure circuit, and means responsive in one brake system condition to pressure loss only at said first outlet port to close said first outlet port and divert brake pressure from said first inlet port to said second outlet port, so that both of said inlet ports supply brake pressure only to said second outlet port, said means being responsive in another brake system condition to pressure loss only at said second outlet port to severely restrict said second outlet port.
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) | 1977-12-09 | 1978-06-10 | 1978-12-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-12-09 | 1982-06-10 | 1982-12-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-12-09 | 1986-06-10 | 1986-12-10 | $7700.00 | Window Closed / Lapsed |