US3575001A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Master cylinder for braking systems
Assignee: Girling Ltd
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Filing: 1969-06-16
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Granted: 1971-04-13
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Expires: 1989-06-16
Abstract
Abstract In a master cylinder a spring loaded tilting valve controls communication between a source of fluid, such as a reservoir of high pressure supply, and a pressure space in the cylinder, and the tilting valve comprises a head member mounted on the upper end of a stem. The head member is adapted to seat against a valve seating member surrounding a port for connection to the source of fluid, and an annular projection is provided on one of the members for engagement with a complementary surface on the other member.
Inventors
- 👤 Alexander J Wilson
- 👤 Stuart B Dawson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 10:50
CPC Classifications
B; B60; B60T; B60T13/00; B60T13/10; B60T13/12; B60T13/14; B60T13/142; B60T13/145; B60T13/146
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
237 words
In a master cylinder for an hydraulic braking system comprising a cylinder body having a wall defining a cylinder bore, means defining a pressure space in the cylinder bore, a piston assembly moveable axially in said pressure space, a valve seating member in said wall having a port for connection to a source of fluid, and a tilting valve controlling communication between said port and said pressure space through an opening in a portion of said wall and comprising a valve head member, a compression spring adapted to urge said valve head member into engagement with said valve seating member to close said port, and a stem having an upper end upon which said valve head member is carried and a lower end extending into said pressure space through said opening and with which said piston assembly is adapted to engage to hold said tilting valve in an open position whereby communication between said pressure space and said source of fluid is established, the improvement comprising an annular projection of small area provided on one of said members, and the other of said members is provided with a surface complementary to said annular projection which is adapted to engage therewith to close said port, wherein said projection is divided into inner and outer concentric rings by an annular groove, and said outer concentric ring is provided with a radial passage connecting said groove with said pressure space.
Claim 2
Dependent Claim
237 words
In a master cylinder for an hydraulic braking system comprising a cylinder body having a wall defining a cylinder bore, means defining a pressure space in the cylinder bore, a piston assembly moveable axially in said pressure space, a valve seating member in said wall having a port for connection to a source of fluid, and a tilting valve controlling communication between said port and said pressure space through an opening in a portion of said wall and comprising a valve head member, a compression spring adapted to urge said valve head member into engagement with said valve seating member to close said port, and a stem having an upper end upon which said valve head member is carried and a lower end extending into said pressure space through said opening and with which said piston assembly is adapted to engage to hold said tilting valve in an open position whereby communication between said pressure space and said source of fluid is established, the improvement comprising an annular projection of small area provided on one of said members, and the other of said members is provided with a surface complementary to said annular projection which is adapted to engage therewith to close said port, wherein said projection is divided into inner and outer concentric rings by an annular groove, and said outer concentric ring is provided with a radial passage connecting said groove with said pressure space.
Claim 3
Dependent Claim
34 words
The improvement as claimed in claim 1, wherein said outer ring has a radially outermost diametrical edge providing a fulcrum about which said valve head member is adapted to tilt to open said valve.
Claim 4
Dependent Claim
30 words
The improvement as claimed in claim 1, wherein said tilting valve is housed within a chamber between said valve seating member and said portion of said wall containing said opening.
Claim 5
Dependent Claim
22 words
The improvement as claimed in claim 1, wherein said annular projection is provided on said valve seating member and surrounds said port.
Claim 6
Dependent Claim
18 words
The improvement as claimed in claim 1, wherein said annular projection is provided on said valve head member.
Claim 7
Dependent Claim
25 words
The improvement as claimed in claim 1, wherein said compression spring acts between said head member and said portion of said wall surrounding said opening.
Claim 8
Dependent Claim
64 words
The improvement as claimed in claim 1, wherein a stem extending through said port has an inner end secured to said valve head member and an outer end and said compression spring acts between said outer end of said stem extending through said port and a side of said valve seating member opposite to that with which said head member is adapted to engage.
Claim 9
Dependent Claim
23 words
The improvement as claimed in claim 1, wherein said compression spring is of conical outline having opposite ends of smaller and greater diameters.
Claim 10
Dependent Claim
36 words
The improvement as claimed in claim 8, wherein said smaller diameter end of said conical compression spring acts on said valve head member over an annulus having a diameter greater than that of said annular projection.
Claim 11
Dependent Claim
40 words
The improvement as claimed in claim 8, wherein said smaller diameter end of said conical compression spring acts on said valve head member over an annulus having a diameter less than that of the maximum diameter of said annular projection.
Claim 12
Dependent Claim
20 words
The improvement as claimed in claim 1, wherein said compression spring is of a constant diameter through its axial length.
Claim 13
Dependent Claim
34 words
The improvement as claimed in claim 11, wherein said compression spring acts on said valve head member over an annulus having a diameter less than that of the maximum diameter of said annular projection.
Claim 14
Dependent Claim
79 words
The improvement as claimed in claim 1 incorporating a pair of axially spaced spring-loaded tilting valves, each valve having a stem which extends into the pressure space through an opening in said cylinder wall, and said valves are opened alternatively by the engagement with the said stems of said valves of opposite ends of said piston to establish communication between a reservoir and said pressure space, and between a source of hydraulic fluid under pressurE and said pressure space.
Claim 15
Dependent Claim
91 words
The improvement as claimed in claim 13, wherein said pressure space comprises a primary pressure space for applying fluid under pressure to brakes of a primary braking circuit, said primary pressure space being defined between a positively actuated main piston working in said cylinder bore and an adjacent end of a secondary piston working in said cylinder bore, and a secondary pressure space located between said secondary piston and an adjacent end wall of the cylinder bore is adapted to apply fluid under pressure to brakes of a secondary brake circuit.
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) | 1974-04-12 | 1974-10-12 | 1975-04-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-04-12 | 1978-10-12 | 1979-04-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-04-12 | 1982-10-12 | 1983-04-13 | $7700.00 | Window Closed / Lapsed |