US3914736A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Dual brake system fault detection device
Assignee: Toyota Motor Corp
•
Filing: 1974-04-19
•
Granted: 1975-10-21
•
Expires: 1994-04-19
Abstract
Abstract A fault detection device for a dual brake system comprises means for sensing a pressure imbalance in the system whereby a signal may be generated indicating the occurrence of a fault in the system. The sensing means may be provided in juxtaposition with a regulating valve in a rear brake circuit for sensing the rear master cylinder oil pressure and rear wheel cylinder oil pressure in said circuit or it may be disposed on the master cylinder side between the rear brake circuit and front brake circuit to sense the master cylinder oil pressures in the two circuits. When a pressure imbalance indicating trouble arises in the brake system, switch means responsive to the sensing means is operated due to the imbalance to light a warning lamp.
Inventors
- 👤 Hiroyuki Nakamura
- 👤 Hiroshi Kawaguchi
- 👤 Kiyoshi Nishiwaki
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 22:40
CPC Classifications
B; B60; B60T; B60T8/00; B60T8/26; B60T17/00; B60T17/18; B60T17/22; B60T17/226
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
144 words
A fault detection device for a vehicle dual brake system including brake actuating means, a front brake circuit including a front master cylinder and front wheel cylinders, a rear brake circuit including a rear master cylinder and rear wheel cylinder, conduit means operatively connecting said master cylinders to apply braking fluid pressure to said wheel cylinders to brake said vehicle in response to operation of said actuating means, and regulating valve means reducing in said rear wheel cylinders the rate of rise of braking fluid pressure therein after said pressure has exceeded a predetermined level, said fault detection device comprising means for sensing a predetermined level of pressure imbalance between said rear master cylinder and said rear wheel cylinders, and signal means responsive to said sensing means for generating a signal upon occurrence of said prEssure imbalance to indicate a fault in said system.
Claim 2
Dependent Claim
144 words
A fault detection device for a vehicle dual brake system including brake actuating means, a front brake circuit including a front master cylinder and front wheel cylinders, a rear brake circuit including a rear master cylinder and rear wheel cylinder, conduit means operatively connecting said master cylinders to apply braking fluid pressure to said wheel cylinders to brake said vehicle in response to operation of said actuating means, and regulating valve means reducing in said rear wheel cylinders the rate of rise of braking fluid pressure therein after said pressure has exceeded a predetermined level, said fault detection device comprising means for sensing a predetermined level of pressure imbalance between said rear master cylinder and said rear wheel cylinders, and signal means responsive to said sensing means for generating a signal upon occurrence of said prEssure imbalance to indicate a fault in said system.
Claim 3
Dependent Claim
135 words
A device according to claim 1 wherein said sensing means comprise a stepped cylinder having a small diameter end and a large diameter end, means defining a fluid pressure chamber at each of said ends of said cylinder, a stepped piston movably mounted in said stepped cylinder for movement therein in response to pressure imbalances between said fluid pressure chambers, and spring means for resisting movement of said piston for pressure imbalances below a predetermined level occurring during normal braking operation of said system, and wherein said signal means comprise switch means responsive to movement of said stepped piston to generate a signal upon movement of said piston occurring as a result of a predetermined level of pressure imbalance in said pressure chambers to thereby indicate the occurrence of a fault in said braking system.
Claim 4
Dependent Claim
47 words
A device according to claim 2 wherein said oil pressure chamber on said large diameter end of said cylinder is connected with said rear wheel cylinders and wherein said oil pressure chamber on said small diameter and of said cylinder is connected with said rear master cylinder.
Claim 5
Dependent Claim
47 words
A device according to claim 2 wherein said oil pressure chamber on said larger diameter end of said cylinder is connected with said rear brake circuit and wherein said oil pressure chamber on said small diameter end of said cylinder is connected with said front brake circuit.
References Cited (Backward Citations)
US3698771A
Cited
US3672728A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-10-20 | 1979-04-21 | 1979-10-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-10-20 | 1983-04-21 | 1983-10-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-10-20 | 1987-04-21 | 1987-10-21 | $7700.00 | Window Closed / Lapsed |