US3877759A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Vehicle anti-skid device
Assignee: Nissan Motor Co Ltd
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Filing: 1973-12-20
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Granted: 1975-04-15
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Expires: 1993-12-20
Abstract
Abstract A vehicle brake cylinder is normally hydraulically actuable from a manually operated master cylinder through a modulator valve and a bypass valve. When a skid condition such as excessive wheel deceleration is sensed, the modulator valve is closed and drains some fluid from the brake cylinder to reduce the braking force applied to the vehicle wheels. If a pump used to supply actuating fluid to the modulator valve fails, the modulator valve is bypassed and the brake cylinder is actuable from the master cylinder through the bypass valve only.
Inventors
- 👤 Tomoyoshi Sekiguchi
- 👤 Yasuhisa Takeuchi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 17:31
CPC Classifications
B; B60; B60T; B60T8/00; B60T8/32; B60T8/34; B60T8/42; B60T8/4208; B60T8/4225; B60T13/00; B60T13/10; B60T13/12; B60T13/14; B60T8/88; B60T8/92; B60T8/94
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
351 words
An anti-skid device for a braking system of a vehicle having a manually actuable master cylinder, a brake cylinder communicable with the master cylinder and operative to apply braking force to a vehicle brake assembly in response to fluid fed thereinto under pressure from the master cylinder, a source of fluid pressure, and a sensor responsive to a selected vehicle operating parameter and operative to generate an electrical skid signal when level of the parameter is above a predetermined value indicating that the vehicle is in a skid condition; said antiskid control device comprising: a modulator valve disposed between the master cylinder and the brake cylinder and being communicable with the source of fluid under pressure; a control valve disposed between the source and said modulator valve and being normally open to allow fluid communication therebetween; said control valve being operative to close and thereby block fluid communication between the source and said modulator valve and fluid under substantially atmospheric pressure in response to the skid signal; said modulator valve being operative to allow fluid flow therethrough when said control valve is open, and to block fluid flow therethrough and partially drain fluid from the brake cylinder to reduce the braking force applied by the brake cylinder to the brake assembly when said control valve is closed; a bypass valve communicating with the source and being operative to allow fluid flow between the master cylinder and the brake cylinder through said modulator valve when the pressure of fluid in the source is above a predetermined level, and to block fluid flow through said modulator valve and provide a bypass fluid flow path around said modulator valve when the pressure of fluid in the source is below said predetermined level; and an emergency control device including switch means for producing an electric actuation signal when the pressure of fluid in the source is below a predetermined level and a module connected to said switch means and said control valve for actuating said control valve so as to hold said piston at said position of maximum extension when it receives said actuation signal.
Claim 2
Dependent Claim
351 words
An anti-skid device for a braking system of a vehicle having a manually actuable master cylinder, a brake cylinder communicable with the master cylinder and operative to apply braking force to a vehicle brake assembly in response to fluid fed thereinto under pressure from the master cylinder, a source of fluid pressure, and a sensor responsive to a selected vehicle operating parameter and operative to generate an electrical skid signal when level of the parameter is above a predetermined value indicating that the vehicle is in a skid condition; said antiskid control device comprising: a modulator valve disposed between the master cylinder and the brake cylinder and being communicable with the source of fluid under pressure; a control valve disposed between the source and said modulator valve and being normally open to allow fluid communication therebetween; said control valve being operative to close and thereby block fluid communication between the source and said modulator valve and fluid under substantially atmospheric pressure in response to the skid signal; said modulator valve being operative to allow fluid flow therethrough when said control valve is open, and to block fluid flow therethrough and partially drain fluid from the brake cylinder to reduce the braking force applied by the brake cylinder to the brake assembly when said control valve is closed; a bypass valve communicating with the source and being operative to allow fluid flow between the master cylinder and the brake cylinder through said modulator valve when the pressure of fluid in the source is above a predetermined level, and to block fluid flow through said modulator valve and provide a bypass fluid flow path around said modulator valve when the pressure of fluid in the source is below said predetermined level; and an emergency control device including switch means for producing an electric actuation signal when the pressure of fluid in the source is below a predetermined level and a module connected to said switch means and said control valve for actuating said control valve so as to hold said piston at said position of maximum extension when it receives said actuation signal.
Claim 3
Dependent Claim
193 words
A device as claimd in claim 1, in which said modulator valve includes: a firt chamber communicating with the master cylinder; a second chamber communicable with the brake cylinder; an axial passageway formed between said first and second chambers; a normally closed shut-off valve disposed in said passageway; and a piston having one end communicable with the source and other end extending into said second chamber; said piston being engageable with said shut-off value; said piston being operative to move to a position of maximum extension into said second chamber and engage with and open said shut-off valve to allow fluid to flow through said passageway when fluid under pressure is applied to said end thereof from the source, and to move to a position of minimum extension into said second chamber and disengage from said shut-off valve to allow said shut-off valve to close and block fluid flow through said passageway when application of fluid under pressure is terminated; said piston by moving from said position of maximum extension to said position of Minimum extension thereby reducing the effective volume of said second chamber and partially draining fluid from the brake cylinder.
Claim 4
Dependent Claim
118 words
A device as claimed in claim 2, in which said bypass valve includes: a first inlet communicating with the master cylinder; a second inlet communicating with said second chamber of said modulator valve; an outlet communicating with the brake cylinder; and a valve spool operative to selectively provide fluid communication between said outlet and said first and second inlets and having one end thereof communicating with the source; said valve spool providing fluid communication between said second inlet and said outlet when the pressure of fluid in the source is above said predetermined level, and providing fluid communication between said first inlet and said outlet when the pressure of fluid in the source is below said predetermined level.
Claim 5
Dependent Claim
44 words
A device as claimed in claim 3, in which said bypass valve further includes a biased cam follower engaging with a cam surface of said valve spool to apply a force to said valve spool to urge the same away from a predetermined position.
Claim 6
Dependent Claim
220 words
A device as claimed in claim 2, in which said bypass valve includes: a first inlet communicating with the master cylinder; a second inlet communicating with said second chamber of said modulator valve; a first outlet communicating with the brake cylinder; a second outlet communicating with said first chamber of said modulator valve; a first valve element disposed between said first inlet and said first outlet and being biased to block fluid communication therebetween; a second valve element disposed between said first inlet and said second outlet and being biased to block fluid communication therebetween; a third valve element disposed between said second inlet and said first outlet and being biased to block fluid communication therebetween; and a valve spool communicating with the source and being engageable with said first, second and third valve elements; said valve spool being operative to move said second and third valve elements to positions to allow fluid communication between said first inlet and said second outlet and between said second inlet and said first outlet respectively when the pressure of fluid in the source is above said predetermined level, and to move said first valve element to a position to allow fluid communication between said first inlet and said first outlet when the pressure of fluid in the source is below said predetermined level.
Claim 7
Dependent Claim
45 words
An anti-skid device as claimed in claim 1, in which said switch means includes a mechanical switch with a movable rod mechanically connected with said valve spool, said mechanical switch being actuated to close or open in accordance with the movement of said movable rod.
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) | 1978-04-14 | 1978-10-14 | 1979-04-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-04-14 | 1982-10-14 | 1983-04-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-04-14 | 1986-10-14 | 1987-04-15 | $7700.00 | Window Closed / Lapsed |