Patent US4280440A successfully refreshed from Google Patents.
US3974899A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Steering brake system for use in track-type vehicles
Assignee: Komatsu Ltd
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Filing: 1975-05-07
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Granted: 1976-08-17
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Expires: 1995-05-07
Abstract
Abstract Braking system for use in track-type vehicles. The system includes a steering brake, a brake cylinder in which an emergency brake piston and a spring for biassing the emergency brake piston to its braking position are provided. The emergency brake piston is operatively connected to the steering brake through a link mechanism and defines with the braking cylinder a hydraulic pressure receiving chamber connected to a hydraulic fluid supply source to maintain the emergency brake piston in its non-braking position against a biassing action of the spring in case of the normal condition of the vehicle. The link mechanism comes into contact with an auxiliary lever serving to move the emergency brake piston to its non-braking position.
Inventors
- 👤 Masazo Mita
- 👤 Masatsugu Nagatomo
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 09:55
CPC Classifications
B; B60; B60T; B60T11/00; B60T11/10; B60T11/103; B60T13/00; B60T13/10; B60T13/12; B60T13/22; B60W; B60W10/00; B60W10/04; B60W10/18
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
277 words
A steering brake system for use in a track-type vehicle which comprises a steering brake, a brake cylinder, an emergency brake piston slidably inserted into the brake cylinder and operatively connected to the steering brake through a first link mechanism including a brake lever, a spring means provided within the brake cylinder to bias the emergency brake piston toward its braking position, a hydraulic pressure receiving chamber defined by and between the brake cylinder and the emergency brake piston and connected to a hydraulic fluid supply circuit to maintain the emergency brake piston in its non-braking position against the action of the spring means in case of the normal condition of the vehicle, a brake pedal, a drain connected to the hydraulic fluid supply circuit through a first drain circuit including a variable pressure reducing valve for controlling hydraulic pressure within the hydraulic pressure receiving chamber in the brake cylinder and the hydraulic fluid supply circuit in response to a degree of depression of a brake pedal, said brake pedal being connected to said variable pressure reducing valve through a second link mechanism, said valve having drain ports each connected to the first drain circuit to drain away therefrom hydraulic fluid in case of emergency of the vehicle, and an auxiliary lever having one end adapted to contact the brake lever when the emergency brake is operated and the other end connected to the brake pedal through an auxiliary link mechanism, wherein the emergency brake can be released by urging the emergency brake piston toward its non-braking position against the action of the spring means by the depression of the brake pedal without using any hydraulic pressure.
Claim 2
Dependent Claim
277 words
A steering brake system for use in a track-type vehicle which comprises a steering brake, a brake cylinder, an emergency brake piston slidably inserted into the brake cylinder and operatively connected to the steering brake through a first link mechanism including a brake lever, a spring means provided within the brake cylinder to bias the emergency brake piston toward its braking position, a hydraulic pressure receiving chamber defined by and between the brake cylinder and the emergency brake piston and connected to a hydraulic fluid supply circuit to maintain the emergency brake piston in its non-braking position against the action of the spring means in case of the normal condition of the vehicle, a brake pedal, a drain connected to the hydraulic fluid supply circuit through a first drain circuit including a variable pressure reducing valve for controlling hydraulic pressure within the hydraulic pressure receiving chamber in the brake cylinder and the hydraulic fluid supply circuit in response to a degree of depression of a brake pedal, said brake pedal being connected to said variable pressure reducing valve through a second link mechanism, said valve having drain ports each connected to the first drain circuit to drain away therefrom hydraulic fluid in case of emergency of the vehicle, and an auxiliary lever having one end adapted to contact the brake lever when the emergency brake is operated and the other end connected to the brake pedal through an auxiliary link mechanism, wherein the emergency brake can be released by urging the emergency brake piston toward its non-braking position against the action of the spring means by the depression of the brake pedal without using any hydraulic pressure.
Claim 3
Dependent Claim
107 words
A steering brake system as set forth in claim 1, further comprising an auxiliary drain circuit of which one end thereof is connected to the drain and the other end is connected to the hydraulic fluid supply circuit through a check valve, the auxiliary drain circuit being provided therein with an auxiliary selector valve manually operated to open or close the auxiliary drain circuit, whereby hydraulic fluid may be drained away through the auxiliary drain circuit and the auxiliary selector valve to operate the emergency brake at a moment when the vehicle is confronted with an emergency even when any trouble happens in the first drain circuit.
Claim 4
Dependent Claim
131 words
A steering brake system as set forth in claim 2, further comprising a cylinder-piston assembly within which a hydraulic pressure receiving chamber defined by and between the cylinder and the piston is formed and a spring for biassing the piston is provided, a conduit having a check valve, the conduit being connected between the hydraulic fluid supply circuit and the hydraulic pressure receiving chamber of the cylinder-piston assembly, a drain line connected between a drain port of the auxiliary selector valve and the conduit downstream the check valve provided in the conduit, and a deceleration lever for decelerating the engine speed connected through a piston rod to the piston of the cylinder-piston assembly, whereby the engine of the vehicle is made in a low-idling simultaneously when the emergency brake is operated.
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) | 1979-08-17 | 1980-02-16 | 1980-08-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-08-17 | 1984-02-16 | 1984-08-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-08-17 | 1988-02-16 | 1988-08-17 | $7700.00 | Window Closed / Lapsed |