US3652985A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Alarm system for vehicle hydraulic pressure circuit
Assignee: Toyota Motor Corp
•
Filing: 1970-08-05
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Granted: 1972-03-28
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Expires: 1990-08-05
Abstract
Abstract Alarm system for hydraulic pressure circuit provides warning regarding functional deterioration or failure in hydraulic pressure circuit such as oil pressure circuit of hydraulic brake system of vehicle. System comprises pulse generator for periodically obtaining hydraulic pressure pulses representative of pressure in hydraulic pressure circuit. Pressure converter located in hydraulic pressure circuit changes hydraulic pressure pulses into electric pulses, and detecting circuit detects difference between waveform of electric pulses obtained by pressure converter and waveform of electric pulses representative of pressure in hydraulic pressure circuit when circuit is normal. Alarm device connected to detecting circuit is energized when waveform of electric pulses from pressure converter differs from waveform of electric pulses representative of pressure in hydraulic pressure circuit when circuit is normal.
Inventors
- 👤 Toru Toshioka
- 👤 Toshinobu Kuroyama
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 17:34
CPC Classifications
B; B60; B60T; B60T17/00; B60T17/18; B60T17/22
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
126 words
An alarm system for a hydraulic pressure circuit comprising at least one pulse generator for periodically obtaining hydraulic pulses representative of the pressure in the hydraulic pressure circuit, a pressure converter in the hydraulic pressure circuit for converting the hydraulic pulses to electric pulses, a detecting circuit for detecting a difference between the waveform of the electric pulses obtained by the pressure converter and the waveform of electric pulses representative of the pressure in the hydraulic pressure circuit when the circuit is normal, and an alarm connected to the detecting circuit energized by the circuit when the waveform of electric pulses from the pressure converter differs from the waveform of electric pulses representative of the pressure in the hydraulic pressure circuit when the latter is normal.
Claim 2
Dependent Claim
126 words
An alarm system for a hydraulic pressure circuit comprising at least one pulse generator for periodically obtaining hydraulic pulses representative of the pressure in the hydraulic pressure circuit, a pressure converter in the hydraulic pressure circuit for converting the hydraulic pulses to electric pulses, a detecting circuit for detecting a difference between the waveform of the electric pulses obtained by the pressure converter and the waveform of electric pulses representative of the pressure in the hydraulic pressure circuit when the circuit is normal, and an alarm connected to the detecting circuit energized by the circuit when the waveform of electric pulses from the pressure converter differs from the waveform of electric pulses representative of the pressure in the hydraulic pressure circuit when the latter is normal.
Claim 3
Dependent Claim
38 words
An alarm system as in claim 1 in combination with a hydraulic pressure circuit that includes a master brake cylinder, an individual brake wheel cylinder, and a line interconnecting the master brake cylinder and the individual brake cylinder.
Claim 4
Dependent Claim
169 words
An alarm system as in claim 1 wherein the pulse generator comprises a cylinder with a flexible diaphragm that divides the cylinder into first and second chambers, a first line connecting the first chamber to a source of negative pressure, a second line interconnecting the two chambers, a valve in the second line having an open position to provide communication between the chambers and a closed position to separate the chambers, a vent associated with the valve for venting the second chamber when the valve is closed whereby the flexible diaphragm is urged in the direction of the first chamber when the valve is closed, control means to periodically open and close the valve, and a piston in the hydraulic pressure circuit for generating hydraulic pulses with means interconnecting the flexible diaphragm and the piston whereby hydraulic pulses are generated when the control means closes the valve and the flexible diaphragm is urged in the direction of the first chamber to thereby urge the piston in the same direction.
Claim 5
Dependent Claim
27 words
An alarm system as in claim 3 wherein the piston in the hydraulic pressure circuit is associated with the master brake cylinder of a vehicle braking system.
References Cited (Backward Citations)
US3454925A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-03-28 | 1975-09-27 | 1976-03-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-03-28 | 1979-09-27 | 1980-03-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-03-28 | 1983-09-27 | 1984-03-28 | $7700.00 | Window Closed / Lapsed |