US3889469A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Tandem master cylinder with in-line check valves
Assignee: Caterpillar Inc
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Filing: 1974-01-21
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Granted: 1975-06-17
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Expires: 1994-01-21
Abstract
Abstract There is disclosed a dual master cylinder having axially disposed pistons within a single cylinder for actuating separate circuits of a brake system of a vehicle. Check valves for the separate circuits are disposed co-axially at one end of the cylinder.
Inventors
- 👤 John R Cryder
- 👤 Lowell R Hall
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 08:38
CPC Classifications
B; B60; B60T; B60T11/00; B60T11/10; B60T11/16; B60T11/20; B60T11/28
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
139 words
A tandem master cylinder assembly for a dual brake system, said assembly comprising: a housing having an elongated cylindrical bore formed therein, said bore having a first end and a second end; a fluid reservoir adjacent said bore and communicating therewith; first and second pistons axially reciprocably mounted in said bore for movement in a forward direction toward said first end and a rearward direction toward said second end and operative upon movement in said forward direction to pressurize fluid within said cylinder ahead of said respective pistons, said pistons dividing said bore into first and second chambers; first and second outlet means for separately communicating pressurized fluid from each of said first and second chambers; and, first and second check valve means disposed along the axis of said bore at said first end for separately controlling said outlets.
Claim 2
Dependent Claim
139 words
A tandem master cylinder assembly for a dual brake system, said assembly comprising: a housing having an elongated cylindrical bore formed therein, said bore having a first end and a second end; a fluid reservoir adjacent said bore and communicating therewith; first and second pistons axially reciprocably mounted in said bore for movement in a forward direction toward said first end and a rearward direction toward said second end and operative upon movement in said forward direction to pressurize fluid within said cylinder ahead of said respective pistons, said pistons dividing said bore into first and second chambers; first and second outlet means for separately communicating pressurized fluid from each of said first and second chambers; and, first and second check valve means disposed along the axis of said bore at said first end for separately controlling said outlets.
Claim 3
Dependent Claim
21 words
The master cylinder assembly of claim 1 wherein said check valves are coaxially disposed within the first end of said bore.
Claim 4
Dependent Claim
47 words
The master cylinder assembly of claim 1 comprising a valve seat and manifold assembly removably mounted in said first end of said bore; and means communicating said first and second chambers defined by said pistons in said bore with said outlets via said manifold and valve seat.
Claim 5
Dependent Claim
25 words
The master cylinder assembly of claim 3 wherein said valve and manifold assembly includes annular means communicating said first chamber with one of said outlets.
Claim 6
Dependent Claim
50 words
The master cylinder assembly of claim 1 comprising: biasing means for biasing said first and second pistons away from said first end to their respective rearmost positions within said bore; and, said biasing means including means independent of the first piston for biasing the second piston to its rearmost position.
Claim 7
Dependent Claim
32 words
The master cylinder assembly of claim 1 comprising: means detachably mounted in said bore intermediate said pistons for defining stop means for limiting the rearward travel of the first of said pistons.
Claim 8
Dependent Claim
23 words
The master cylinder assembly of claim 6 wherein said stop means comprises a ring member detachably secured within said bore between said pistons.
Claim 9
Dependent Claim
51 words
The master cylinder assembly of claim 7 comprising biasing means independent of said first piston for biasing the second of said pistons to its rearmost position within said bore, said biasing means including a compression spring mounted between and in engagement with said ring member and the second of said pistons.
Claim 10
Dependent Claim
51 words
The master cylinder assembly of claim 7 wherein the first of said pistons includes a rearward extension extending beyond said stop means for engagement by the forward end of said second piston for actuation thereof only if fluid pressure between said pistons should fail during forward movement of said second piston.
Claim 11
Dependent Claim
69 words
The master cylinder assembly of claim 3 wherein said manifold assembly separates said first chamber from a valve chamber at the first end of said bore and includes means communicating the pressure from said second chamber via said second outlet with the rear wheel brakes of a vehicle; and, the first of said outlets communicates the pressure in the first chamber with the front wheel brakes of a vehicle.
References Cited (Backward Citations)
US3191385A
Cited
US3210941A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-06-16 | 1978-12-16 | 1979-06-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-06-16 | 1982-12-16 | 1983-06-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-06-16 | 1986-12-16 | 1987-06-17 | $7700.00 | Window Closed / Lapsed |