US3705643A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Brake & clutch control for industrial track
Assignee: Toyota Industries Corp
•
Filing: 1970-06-25
•
Granted: 1972-12-12
•
Expires: 1990-06-25
Abstract
Abstract The fluid control system applied to the industrial trucks, is provided with a check valve in a fluid line between a master cylinder and a plurality of wheel cylinders so as to interrupt the return flow of brake oil from the wheel cylinders to the master cylinder, and an interfering means in a bypass line to the check valve so as to admit the return flow of the brake oil in a controlled or restricted condition when the oil pressure in the hydraulic clutches reach to a sufficient pressure for engaging the clutches.
Inventors
- 👤 Seijiro Iwaoka
- 👤 Hiroo Mori
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 04:33
CPC Classifications
B; B60; B60T; B60T11/00; B60T11/10; B60T11/103; Y; Y10; Y10S; Y10S188/00; Y10S188/02
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
187 words
In an industrial truck having a single brake pedal, a master cylinder operated by said brake pedal, a pair of wheel cylinders for imparting braking force to said truck by fluid supply from said master cylindEr, a hydraulic line connecting said master cylinder with said wheel cylinders, a hydraulic pump driven by an engine, fluid actuated clutch means for driving said truck and a fluid supply line connecting said pump with said clutch means, a fluid control system comprising a check valve in said hydraulic line to block return flow of fluid from said wheel cylinders to said master cylinder, a bypass fluid line shunting said check valve to permit return flow of fluid from said wheel cylinders to said master cylinder without passing through said check valve, control valve means for controlling said return flow through said bypass fluid line, a cut-off valve arranged in said fluid supply line between said pump and clutch means, means for operating said cut-off valve including means fluidly connecting said master cylinder and said cut-off valve, and means operably connected with said cut-off valve for operating said control valve means.
Claim 2
Dependent Claim
187 words
In an industrial truck having a single brake pedal, a master cylinder operated by said brake pedal, a pair of wheel cylinders for imparting braking force to said truck by fluid supply from said master cylindEr, a hydraulic line connecting said master cylinder with said wheel cylinders, a hydraulic pump driven by an engine, fluid actuated clutch means for driving said truck and a fluid supply line connecting said pump with said clutch means, a fluid control system comprising a check valve in said hydraulic line to block return flow of fluid from said wheel cylinders to said master cylinder, a bypass fluid line shunting said check valve to permit return flow of fluid from said wheel cylinders to said master cylinder without passing through said check valve, control valve means for controlling said return flow through said bypass fluid line, a cut-off valve arranged in said fluid supply line between said pump and clutch means, means for operating said cut-off valve including means fluidly connecting said master cylinder and said cut-off valve, and means operably connected with said cut-off valve for operating said control valve means.
Claim 3
Dependent Claim
51 words
A fluid control system according to claim 1, wherein said means for operating said control valve means comprises means for transmitting hydraulic pressure for actuating said control valve means to open said bypass fluid line when hydraulic pressure in said fluid supply line to said clutch means exceeds a predetermined value.
Claim 4
Dependent Claim
52 words
A fluid control system according to claim 1, wherein said cut-off valve is operably connected with said means for operating said control valve means so that said bypass fluid line is opened by actuating said control valve means after said cut-off valve provides communication from said pump to said clutches clutch means.
Claim 5
Dependent Claim
42 words
A fluid control system according to claim 1, wherein said clutch means comprises a pair of clutches and wherein a manually operable valve is provided in said fluid supply line to direct fluid selectively to one or the other of said clutches.
Claim 6
Dependent Claim
17 words
A fluid control system according to claim 1, comprising a flow-controlling orifice in said bypass fluid line.
Claim 7
Dependent Claim
174 words
A fluid control system according to claim 1, wherein said cut-off valve means comprises a housing having a port connected with said clutch means, a port connected with said pump and a port connected with a fluid discharge, a valve member movable in said housing between a first position in which said port connected with said pump is in communication with said port connected with said clutch means and a second position in which said port connected with said clutch means is in communication with said port connected with said discharge, spring means normally biasing said valve member to said first position, cooperating piston and cylinder means for moving said valve means to said second position against the bias of said spring means, said means for operating said cut-off valve including means fluidly connecting said master cylinder and said cut-off valve comprising a fluid line connecting said master cylinder with said piston and cylinder means for moving said valve member to said second position when said master cylinder is operated by said brake pedal.
Claim 8
Dependent Claim
169 words
A fluid control system according to claim 6, wherein said control valve means comprises a valve housing having a port connected with said master cylinder, and a port connected with said wheel cylinders, a control valve member movable in said housing between a first position in which said ports are not in communication with one another and a second position in which said ports are in communication with one another, spring means for biasing said control valve member normally to said first position, piston and cylinder means for moving said control valve member to said second position against the bias of said spring means, said means operably connected with said cut-off valve for operating said control valve means comprising a fluid line connecting said piston and cylinder means of said control valve means with said port of said cut-off valve connected with said clutch means to move said control valve member to said second position when predetermined fluid pressure is supplied by saiD cut-off valve to said clutch means.
Claim 9
Dependent Claim
27 words
A fluid control system according to claim 7, wherein said bypass fluid line includes fixed metering means for attenuating flow of fluid through said bypass fluid line.
Claim 10
Dependent Claim
27 words
A fluid control system according to claim 7, further comprising a torque converter connected with said pump for driving said truck under control of said clutch means.
References Cited (Backward Citations)
US3181667A
Cited
US3298471A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-12-12 | 1976-06-12 | 1976-12-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-12-12 | 1980-06-12 | 1980-12-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-12-12 | 1984-06-12 | 1984-12-12 | $7700.00 | Window Closed / Lapsed |