US3910046A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Two stage servomotor
Assignee: Bendix Corp
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Filing: 1974-10-02
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Granted: 1975-10-07
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Expires: 1994-10-02
Abstract
Abstract A pressure differential controlled valve for use in a two stage servomotor to delay the communication between a second pressurizing chamber and a first pressurizing chamber until compensatory fluid, which is lost from the first pressurizing chamber in the transfer of the development of an operational force from a first diameter on a power piston to a second diameter on the power piston is replaced.
Inventors
- 👤 Delbert J Gardner
- 👤 William C Sisco
- 👤 Frederick G Grabb
- 👤 Carl D Owens
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 15:14
CPC Classifications
B; B60; B60T; B60T13/00; B60T13/10; B60T13/24; B60T13/46; B60T13/52; B60T13/565
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
426 words
In a power braking system having a piston means moved by a wall means which responds to a valve means operated by an input force, said piston means producing a first fluid force in a first mode of operation and a second fluid force in a second mode of operation, said valve means permitting a volume of fluid to be communicated from the braking system to a relief chamber proportional to the input force to develop the second mode of operation, control means associated with the piston means for preventing fluid communication between the second mode of operation and the first mode of operation with a reduction in the input force until compensatory fluid is provided to the braking system for said volume of fluid communicated to the relief chamber, said control means comprising: a housing having a bore therein with a first diameter and a second diameter, said piston means dividing the first diameter into a first pressurizing chamber and said relief chamber, said piston means extending into said second diameter of Said bore to form a second pressurizing chamber therein, said housing having a port means connected to a source of fluid to said first diameter of said bore, said piston means having a first axial bore therethrough with a first radial opening connected to the first pressurizing chamber and a second radial opening connected to the first pressurizing chamber and a second radial opening connected to the relief chamber, first valve means located in the first axial bore of said piston means between the first radial opening and the second radial opening for preventing communication between the first pressurizing chamber and the relief chamber while allowing communication between the first pressurizing chamber and the second pressurizing chamber in said first mode of operation and for interrupting the communication between the first pressurizing chamber and the second pressurizing chamber while allowing communication between the first pressurizing chamber and the relief chamber in said second mode of operation; and second valve means located in said first axial bore of the piston means between the first radial opening and the outlet to the second pressurizing chamber for allowing said first fluid force to be freely communicable between the first pressurizing chamber and the second pressurizing chamber in said first mode of operation and for preventing communication between the second pressurizing chamber and the first pressurizing chamber in the second mode of operation in response to a pressure differential being developed between the first fluid force and the second fluid force in the second mode of operation.
Claim 2
Dependent Claim
426 words
In a power braking system having a piston means moved by a wall means which responds to a valve means operated by an input force, said piston means producing a first fluid force in a first mode of operation and a second fluid force in a second mode of operation, said valve means permitting a volume of fluid to be communicated from the braking system to a relief chamber proportional to the input force to develop the second mode of operation, control means associated with the piston means for preventing fluid communication between the second mode of operation and the first mode of operation with a reduction in the input force until compensatory fluid is provided to the braking system for said volume of fluid communicated to the relief chamber, said control means comprising: a housing having a bore therein with a first diameter and a second diameter, said piston means dividing the first diameter into a first pressurizing chamber and said relief chamber, said piston means extending into said second diameter of Said bore to form a second pressurizing chamber therein, said housing having a port means connected to a source of fluid to said first diameter of said bore, said piston means having a first axial bore therethrough with a first radial opening connected to the first pressurizing chamber and a second radial opening connected to the first pressurizing chamber and a second radial opening connected to the relief chamber, first valve means located in the first axial bore of said piston means between the first radial opening and the second radial opening for preventing communication between the first pressurizing chamber and the relief chamber while allowing communication between the first pressurizing chamber and the second pressurizing chamber in said first mode of operation and for interrupting the communication between the first pressurizing chamber and the second pressurizing chamber while allowing communication between the first pressurizing chamber and the relief chamber in said second mode of operation; and second valve means located in said first axial bore of the piston means between the first radial opening and the outlet to the second pressurizing chamber for allowing said first fluid force to be freely communicable between the first pressurizing chamber and the second pressurizing chamber in said first mode of operation and for preventing communication between the second pressurizing chamber and the first pressurizing chamber in the second mode of operation in response to a pressure differential being developed between the first fluid force and the second fluid force in the second mode of operation.
Claim 3
Dependent Claim
36 words
In the power braking system, as recited in claim 1, wherein said first valve means includes: tilt valve means responsive to said input force for regulating communication between the first pressurizing chamber and the relief chamber.
Claim 4
Dependent Claim
64 words
In the power braking system, as recited in claim 1 wherein said first valve means includes: cylindrical means having a second axial bore therein; poppet means located in said second axial bore; and first resilient means for urging said poppet means toward a seat to maintain a predetermined volume of fluid under pressure in the first pressurizing chamber in the second mode of operation.
Claim 5
Dependent Claim
30 words
In the power braking system, as recited in claim 3 wherein said first valve means further includes: projecting means extending from said cylindrical means for actuating said second valve means.
Claim 6
Dependent Claim
63 words
In the power braking system, as recited in claim 4, wherein said second valve means includes: first sleeve means located in said first axial bore having a seat on one end thereof for engaging said projection means upon movement of said first valve means to prevent communication between the first pressurizing chamber and the second pressurizing chamber in said second mode of operation.
Claim 7
Dependent Claim
67 words
In the power braking system, as recited in claim 5 wherein said second valve means further includes: stop means secured to said piston means; and second resilient means located between the stop means and said first sleeve means for urging the seat thereon toward the projection means to assure that the second pressurized chamber is sealed from the first pressurized chamber in the second mode of operation.
Claim 8
Dependent Claim
66 words
In the power braking system, as recited in claim 6 wherein said second valve means further includes: second sleeve means concentric to said first sleeve means having a rib thereon for engaging the first sleeve means; and third resilient means located between said second sleeve means and said projection means for urging said first sleeve means against said stop means in the first mode of operation.
Claim 9
Dependent Claim
137 words
In the power braking system, as recited in claim 7 wherein said projection means includes: disc means located between a shoulder on the end of the projection means, said seat on the first sleeve means engaging the disc means with initial movement of the first valve means to interrupt the communication betweEn the first pressurizing chamber and the second pressurizing chamber, said tilt valve with further movement of the first valve means allowing said first fluid pressure to move said poppet means in opposition to said first resilient means and be released to said relief chamber to create a first pressure differential across said second sleeve means, said first pressure differential across said second sleeve means transmitting a reaction force through the first valve means to inform the operator of the intensity of the second fluid force.
Claim 10
Dependent Claim
122 words
In the power braking system, as recited in claim 8 wherein said control means further includes: check valve means associated with said port means to prevent communication from the first diameter to the source of fluid, said first pressure differential moving the second sleeve means toward the first valve means with a reduction in the input force to develop a second pressure differential across said check valve means between the first pressurizing chamber and said source of fluid, said second pressure differential overcoming said check valve means to allow fluid to be communicated to the first pressurizing chamber until the second resilient means overcomes the first pressure differential to re-establish free communication between the first pressurizing chamber and the second pressurizing chamber.
Claim 11
Dependent Claim
40 words
In the power braking system, as recited in claim 9 wherein said piston means further includes: a third radial opening connecting the second pressurizing chamber with the first pressurizing chamber to assure communication therebetween when the input force is terminated.
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) | 1978-10-06 | 1979-04-07 | 1979-10-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-10-06 | 1983-04-07 | 1983-10-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-10-06 | 1987-04-07 | 1987-10-07 | $7700.00 | Window Closed / Lapsed |