US4251114A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Brake valve
Assignee: ITT Inc
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Filing: 1979-03-30
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Granted: 1981-02-17
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Expires: 1999-03-30
Abstract
Abstract A brake valve comprising two coaxial, tandemly arranged control spools each connecting a different one of two brake circuits to either an associated pressure fluid source or an associated unpressurized reservoir. A first of the two control spools is actuated mechanically by a brake pedal and the second of the two control spools is actuated by the brake pressure controlled by the first of the two control spools. In order for the second of the two control spools to meter the same pressure into the associated brake circuit as the first of the two control spools, the second of the two control spools has two additional effective surfaces, one of which is acted upon by the brake pressure controlled by the first of the two control spools in the direction of actuation and the other of which is acted upon by the brake pressure metered into that one of the two brake circuits controlled by the second of the two control spools.
Inventors
- 👤 Juan Belart
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 07:18
CPC Classifications
B; B60; B60T; B60T13/00; B60T13/10; B60T13/12; B60T13/14; B60T13/141
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
229 words
A brake valve comprising: a housing having a longitudinal axis; a first control spool disposed in said housing coaxial of said axis to connect a first brake circuit to a first unpressurized reservoir in its rest position and to connect said first brake circuit to a first fluid source in its actuated position; a second control spool disposed in said housing coaxial of said axis and in tandem relation with said first control spool to connect a second brake circuit to a second unpressurized reservoir in its rest position and to connect said second brake circuit to a second fluid source in its actuated position; a brake pedal coupled to said first control spool for mechanical actuation thereof; a pressure chamber disposed in said housing in permanent communication with said first brake circuit for hydraulically actuating said second control spool, said second control spool having a first effective surface in said pressure chamber; and an annular piston disposed to encircle and slidably sealed to the outer surface of said second control spool, said annular piston having disposed on opposite ends thereof two additional opposed effective surfaces, a first of said two additional effective surfaces being acted upon by pressure in said pressure chamber and a second of said two additional effective surfaces being acted upon by pressure in a counter-pressure chamber in permanent communication with said second brake circuit.
Claim 2
Dependent Claim
229 words
A brake valve comprising: a housing having a longitudinal axis; a first control spool disposed in said housing coaxial of said axis to connect a first brake circuit to a first unpressurized reservoir in its rest position and to connect said first brake circuit to a first fluid source in its actuated position; a second control spool disposed in said housing coaxial of said axis and in tandem relation with said first control spool to connect a second brake circuit to a second unpressurized reservoir in its rest position and to connect said second brake circuit to a second fluid source in its actuated position; a brake pedal coupled to said first control spool for mechanical actuation thereof; a pressure chamber disposed in said housing in permanent communication with said first brake circuit for hydraulically actuating said second control spool, said second control spool having a first effective surface in said pressure chamber; and an annular piston disposed to encircle and slidably sealed to the outer surface of said second control spool, said annular piston having disposed on opposite ends thereof two additional opposed effective surfaces, a first of said two additional effective surfaces being acted upon by pressure in said pressure chamber and a second of said two additional effective surfaces being acted upon by pressure in a counter-pressure chamber in permanent communication with said second brake circuit.
Claim 3
Dependent Claim
80 words
A valve according to claim 1, wherein said annular piston is held in its normal position against a stop formed in the inner surface of said housing by a spring and displaceable by pressure in said pressure chamber acting upon said first of said two additional effective surfaces into abutment with a collar formed on said second control spool adjacent said second of said two additional effective surfaces against the force of said spring when said brake valve is actuated.
Claim 4
Dependent Claim
16 words
A valve according to claim 2, wherein said two additional effective surfaces are of equal size.
Claim 5
Dependent Claim
16 words
A valve according to claim 1, wherein said two additional effective surfaces are of equal size.
Claim 6
Dependent Claim
82 words
A valve according to claim 1, wherein said permanent communication between said pressure chamber and said first brake circuit includes a first longitudinal bore disposed in said first control spool extending from an end of said first control spool adjacent said pressure chamber toward the other end of said first control spool adjacent said brake pedal, and a first cross bore disposed in said first control spool connected between said first longitudinal bore adjacent said brake pedal and said first brake circuit.
Claim 7
Dependent Claim
70 words
A valve according to claim 5, further including a control housing sealed to the inner surface of said housing into which said first control spool projects, and wherein said second control spool includes an extension on one end thereof adjacent said first control spool projecting into said control housing, and longitudinal grooves disposed in said extension to provide a fluid connection between said first longitudinal bore and said pressure chamber.
Claim 8
Dependent Claim
29 words
A valve according to claim 6, wherein said one end of said first control spool provides a control edge for a reservoir connecting channel disposed in said control housing.
Claim 9
Dependent Claim
145 words
A valve according to claim 7, further including a second longitudinal bore disposed in said second control spool having one end thereof coupled to said second reservoir, a second cross bore disposed in said second control spool having one end thereof connected to the other end of said second longitudinal bore and the other end thereof connected to said counter-pressure chamber, said second longitudinal bore and said second cross bore providing a fluid connection between said second reservoir and said counter-pressure chamber, and a third cross bore disposed in said second control spool having one end thereof coupled to said second fluid source and the other end thereof connected to said second longitudinal bore intermediate the ends thereof, said third cross bore and said second longitudinal bore providing fluid for said counter-pressure chamber and, hence, said second brake circuit upon actuation of said brake valve.
Claim 10
Dependent Claim
37 words
A valve according to claim 8, wherein said second control spool is held against said control housing in its normal position by a spring bearing against an end of said second control spool remote from said extension.
Claim 11
Dependent Claim
70 words
A valve according to claim 1, further including a control housing sealed to the inner surface of said housing into which said first control spool projects, and wherein said second control spool includes an extension on one end thereof adjacent said first control spool projecting into said control housing, and longitudinal grooves disposed in said extension to provide a fluid connection between said pressure chamber and said first brake circuit.
Claim 12
Dependent Claim
29 words
A valve according to claim 10, wherein said one end of said first control spool provides a control edge for a reservoir connecting channel disposed in said control housing.
Claim 13
Dependent Claim
140 words
A valve according to claim 11, further including a longitudinal bore disposed in said second control spool having one end thereof coupled to said second reservoir, a first cross bore disposed in said second control spool having one end thereof connected to the other end of said longitudinal bore and the other end thereof connected to said counter-pressure chamber, said longitudinal bore and said first cross bore providing a fluid connection between said second reservoir and said counter-pressure chamber, and a second cross bore disposed in said second control spool having one end thereof coupled to said second fluid source and the other end thereof connected to said longitudinal bore intermediate the ends thereof, said second cross bore and said longitudinal bore providing fluid for said counter-pressure chamber and, hence, said second brake circuit upon actuation of said brake valve.
Claim 14
Dependent Claim
37 words
A valve according to claim 12, wherein said second control spool is held against said control housing in its normal position by a spring bearing against an end of said second control spool remote from said extension.
Claim 15
Dependent Claim
140 words
A valve according to claim 1, further including a longitudinal bore disposed in said second control spool having one end thereof coupled to said second reservoir, a first cross bore disposed in said second control spool having one end thereof connected to the other end of said longitudinal bore and the other end thereof connected to said counter-pressure chamber, said longitudinal bore and said first cross bore providing a fluid connection between said second reservoir and said counter-pressure chamber, and a second cross bore disposed in said second control spool having one end thereof coupled to said second fluid source and the other end thereof connected to said longitudinal bore intermediate the ends thereof, said second cross bore and said longitudinal bore providing fluid for said counter-pressure chamber and, hence, said second brake circuit upon actuation of said brake valve.
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) | 1984-02-17 | 1984-08-18 | 1985-02-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-02-17 | 1988-08-18 | 1989-02-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-02-17 | 1992-08-18 | 1993-02-17 | $7700.00 | Window Closed / Lapsed |