CA1058255A - Brake release mechanism - Google Patents
Brake release mechanismInfo
- Publication number
- CA1058255A CA1058255A CA278,976A CA278976A CA1058255A CA 1058255 A CA1058255 A CA 1058255A CA 278976 A CA278976 A CA 278976A CA 1058255 A CA1058255 A CA 1058255A
- Authority
- CA
- Canada
- Prior art keywords
- brake
- hydraulic
- shunt
- release mechanism
- manual
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B60—VEHICLES IN GENERAL
- B60T—VEHICLE BRAKE CONTROL SYSTEMS OR PARTS THEREOF; BRAKE CONTROL SYSTEMS OR PARTS THEREOF, IN GENERAL; ARRANGEMENT OF BRAKING ELEMENTS ON VEHICLES IN GENERAL; PORTABLE DEVICES FOR PREVENTING UNWANTED MOVEMENT OF VEHICLES; VEHICLE MODIFICATIONS TO FACILITATE COOLING OF BRAKES
- B60T13/00—Transmitting braking action from initiating means to ultimate brake actuator with power assistance or drive; Brake systems incorporating such transmitting means, e.g. air-pressure brake systems
- B60T13/10—Transmitting braking action from initiating means to ultimate brake actuator with power assistance or drive; Brake systems incorporating such transmitting means, e.g. air-pressure brake systems with fluid assistance, drive, or release
- B60T13/12—Transmitting braking action from initiating means to ultimate brake actuator with power assistance or drive; Brake systems incorporating such transmitting means, e.g. air-pressure brake systems with fluid assistance, drive, or release the fluid being liquid
- B60T13/22—Brakes applied by springs or weights and released hydraulically
Landscapes
- Engineering & Computer Science (AREA)
- Transportation (AREA)
- Mechanical Engineering (AREA)
- Braking Systems And Boosters (AREA)
- Valves And Accessory Devices For Braking Systems (AREA)
- Regulating Braking Force (AREA)
Abstract
BRAKE RELEASE MECHANISM
A B S T R A C T
A brake release mechanism for a spring-loaded, normally applied vehicle brake releasable by system hydraulic pressure when said system is disabled includes a manual cut-off valve for isolating said brake from the disabled system and manual hydraulic pump means communicating with said brake for supplying fluid pressure thereto.
Manual or pilot operated shunt means are provided for shunting a hydraulic motor associated with the brake to allow free turning thereof during towing.
A B S T R A C T
A brake release mechanism for a spring-loaded, normally applied vehicle brake releasable by system hydraulic pressure when said system is disabled includes a manual cut-off valve for isolating said brake from the disabled system and manual hydraulic pump means communicating with said brake for supplying fluid pressure thereto.
Manual or pilot operated shunt means are provided for shunting a hydraulic motor associated with the brake to allow free turning thereof during towing.
Description
This invention relates to vehicles which have hydraulic motors for driving the vehicle, and associated brakes which are normally applied by spring pressure and are releasable by hydraulic pressure supplied by the hydraulic system of the vehicle. In such vehicles, a problem arises upon failure of the power plant or the vehicle hydraulic system, or related systems which affect the hydraulic system, because without system hydraulic pressure the vehicle brakes cannot be released to allow movement of the vehicle to a suitable repair facility.
In accordance with the invention, a vehicle has a hydraulic drive motor, a spring applied brake associated with the drive motor and releasable by hydraulic pressure, a pressurized hydraulic system including a sump for supplying pressure to the brake, and an auxiliary brake release mechanism for releasing the brake and comprising cut-off valve means for isolating the brake from the hydraulic system, auxiliary conduit means connecting the brake with the hydraulic system sump, and manual hydraulic pump means disposed in the auxiliary conduit means for pumping fluid from the sump to the brake.
With this arrangement, normally applied brakes may be hydraulically released for towing or other movement of a vehicle upon failure of the main vehicle brake release hydraulic pressure. The, preferably manual, cut-off valve enables isolation of the brake mechanism for the disabled hydraulic system, and the manual hydraulic pump allows manual pressuri~ation of the vehicle brake for release thereof.
Preferably inlet and exhaust lines of the hydraulic motor are connected by a shunt conduit provided with valve means for interconnecting the inlet and exhaust lines of the motor to allow free turning thereof while
In accordance with the invention, a vehicle has a hydraulic drive motor, a spring applied brake associated with the drive motor and releasable by hydraulic pressure, a pressurized hydraulic system including a sump for supplying pressure to the brake, and an auxiliary brake release mechanism for releasing the brake and comprising cut-off valve means for isolating the brake from the hydraulic system, auxiliary conduit means connecting the brake with the hydraulic system sump, and manual hydraulic pump means disposed in the auxiliary conduit means for pumping fluid from the sump to the brake.
With this arrangement, normally applied brakes may be hydraulically released for towing or other movement of a vehicle upon failure of the main vehicle brake release hydraulic pressure. The, preferably manual, cut-off valve enables isolation of the brake mechanism for the disabled hydraulic system, and the manual hydraulic pump allows manual pressuri~ation of the vehicle brake for release thereof.
Preferably inlet and exhaust lines of the hydraulic motor are connected by a shunt conduit provided with valve means for interconnecting the inlet and exhaust lines of the motor to allow free turning thereof while
-2-,. ~ 1', , ~. ...
s moving the vehicle.
The shunt valve means may be manually operable; or operable by pilot pressure provided by the manual hydraulic pump to shunt the hydraulic motor upon operation of the pump.
Two examples of vehicles constructed in accordance with the invention are illustrated in the accompanying drawings, in which:-Figure 1 is a schematic diagram of the brake release mechanism ofone vehicle having two brakes and two hydraulic motors; and Figure 2 is a similar diagram of the second example.
Referring to Figure 1, the present invention is shown schematically on a vehicle brake system which includes a pair of hydraulic motors 12 for driving the vehicle by means of pressurized hydraulic fluid applied through pressure inlet lines 14 and returned by means of exhaust lines 16.
Associated with each hydraulic motor is a brake mechanism shown schematically at 18, which is of the normally applied type wherein a spring 20 biases the brake mechanism toward an applied configuration, and the brake mechanism is releasable by hydraulic fluid pressure supplied through a brake conduit 22 which selectively supplies hydraulic fluid from a brake control mechanism not shown.
Provided in brake conduit 22 is a manual cut-off valve 24 for isolating the brake mechanisms fram the brake line leading from the brake control mechanism, not shown.
A manual hydraulic pump 26 is disposed in an auxiliary conduit 28 together with associated check valves 30 and 32 for manually pumping hydraulic fluid from the vehicle sump into brake conduit 22.
Shunt conduits 34 communicate the hydraulic motor inlet lines 14 with exhaust lines 16 and have shunt valves 36 disposed therein for manually opening shunt conduits 34 when towing or otherwise moving a disabled vehicle, allowing hydraulic motors 12 to be turned :Ereely by the vehicle traction gear as the vehicle is moved.
When a vehicle embodying the invention just described experiences a hydraulic failure due to either a failure of the vehicle engine or hydraulic pumps, or failure in the hydraulic system lines, hydraulic pressure will be 10 lost in brake conduit 22, and brakes 18 will be applied under the influence of springs 20, stopping the vehicle. If it is thereafter desired to push or tow the vehicle to a suitable repair facility, cut-off valve 24 is closed, and manual pump 26 is actuated to again pressurize brake conduit 22 to release brakes 18.
Shunt valves 36 are opened to allow hydraulic fluid in the hydraulic motors to circulate in the circuit completed by the opened shunt conduits 34.
An alternative embodiment of the present invention is shown in Figure 2 wherein manual shunt valve 36 is replaced by a pair of opposed, pilot operated check valves 38 and 40. A pilot pressure conduit 42 20 communicates from auxiliary conduit 28 to the two piloted operated check valves to open the valves upon pressurization of auxiliary conduit 28 and brake conduit 22 to shunt the hydraulic motors upon pressurization of the brakes for release. A check valve 44 is provided in the pilot pressure conduit to maintain the pressure therein during operation of the manual pump, and a relief valve 46 is provided wliich communicates with brake conduit 22.
Still another alternative shunt valve arrangement could employ a spool valve disposed in the shunt conduit and slidable in response to pilot pressure to open the shunt conduit.
s moving the vehicle.
The shunt valve means may be manually operable; or operable by pilot pressure provided by the manual hydraulic pump to shunt the hydraulic motor upon operation of the pump.
Two examples of vehicles constructed in accordance with the invention are illustrated in the accompanying drawings, in which:-Figure 1 is a schematic diagram of the brake release mechanism ofone vehicle having two brakes and two hydraulic motors; and Figure 2 is a similar diagram of the second example.
Referring to Figure 1, the present invention is shown schematically on a vehicle brake system which includes a pair of hydraulic motors 12 for driving the vehicle by means of pressurized hydraulic fluid applied through pressure inlet lines 14 and returned by means of exhaust lines 16.
Associated with each hydraulic motor is a brake mechanism shown schematically at 18, which is of the normally applied type wherein a spring 20 biases the brake mechanism toward an applied configuration, and the brake mechanism is releasable by hydraulic fluid pressure supplied through a brake conduit 22 which selectively supplies hydraulic fluid from a brake control mechanism not shown.
Provided in brake conduit 22 is a manual cut-off valve 24 for isolating the brake mechanisms fram the brake line leading from the brake control mechanism, not shown.
A manual hydraulic pump 26 is disposed in an auxiliary conduit 28 together with associated check valves 30 and 32 for manually pumping hydraulic fluid from the vehicle sump into brake conduit 22.
Shunt conduits 34 communicate the hydraulic motor inlet lines 14 with exhaust lines 16 and have shunt valves 36 disposed therein for manually opening shunt conduits 34 when towing or otherwise moving a disabled vehicle, allowing hydraulic motors 12 to be turned :Ereely by the vehicle traction gear as the vehicle is moved.
When a vehicle embodying the invention just described experiences a hydraulic failure due to either a failure of the vehicle engine or hydraulic pumps, or failure in the hydraulic system lines, hydraulic pressure will be 10 lost in brake conduit 22, and brakes 18 will be applied under the influence of springs 20, stopping the vehicle. If it is thereafter desired to push or tow the vehicle to a suitable repair facility, cut-off valve 24 is closed, and manual pump 26 is actuated to again pressurize brake conduit 22 to release brakes 18.
Shunt valves 36 are opened to allow hydraulic fluid in the hydraulic motors to circulate in the circuit completed by the opened shunt conduits 34.
An alternative embodiment of the present invention is shown in Figure 2 wherein manual shunt valve 36 is replaced by a pair of opposed, pilot operated check valves 38 and 40. A pilot pressure conduit 42 20 communicates from auxiliary conduit 28 to the two piloted operated check valves to open the valves upon pressurization of auxiliary conduit 28 and brake conduit 22 to shunt the hydraulic motors upon pressurization of the brakes for release. A check valve 44 is provided in the pilot pressure conduit to maintain the pressure therein during operation of the manual pump, and a relief valve 46 is provided wliich communicates with brake conduit 22.
Still another alternative shunt valve arrangement could employ a spool valve disposed in the shunt conduit and slidable in response to pilot pressure to open the shunt conduit.
Claims (7)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. In a vehicle having a hydraulic drive motor, a spring applied brake associated with said drive motor and releasable by hydraulic pressure, and a pressurized hydraulic system including a sump for communicating pressure to said brake, an auxiliary brake release mechanism for releasing said brake comprising, cut-off valve means for isolating said brake from the vehicle hydraulic system, auxiliary conduit means communicating said brake with the hydraulic system sump, and manual hydraulic pump means disposed in said auxiliary conduit means for pumping fluid from the sump to the brake.
2. The release mechanism defined in claim 1 further comprising check valves disposed in said auxiliary conduit means on each side of the manual pump to prevent fluid from returning to the sump.
3. The brake release mechanism defined in claim 2 further comprising manual bypass valve means associated with the hydraulic motor for shunting fluid across said motor.
4. The brake release mechanism defined in claim 2 further comprising shunt means for short circuiting the hydraulic motor for free turning thereof, said shunt means including, shunt conduit means communicating with the inlet and exhaust lines of the hydraulic motor, shunt valve means disposed in said shunt conduit means and being openable a pilot pressure applied thereto, pilot pressure conduit means communicating the output pressure of the manual pump with the shunt valve means, and check valve means disposed in said pilot pressure conduit means.
5. The mechanism defined in claim 4 wherein said shunt valve means comprises check valves disposed in opposing relationship.
6. The mechanism defined in claim 4 wherein said shunt valve means comprise a spool valve slidable in response to pilot pressure to complete communication through the shunt conduit means.
7. The brake release mechanism defined in claim 1 wherein the vehicle includes a plurality of hydraulic motors and associated brakes arranged in parallel.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US71442776A | 1976-08-13 | 1976-08-13 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1058255A true CA1058255A (en) | 1979-07-10 |
Family
ID=24869993
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA278,976A Expired CA1058255A (en) | 1976-08-13 | 1977-05-24 | Brake release mechanism |
Country Status (5)
| Country | Link |
|---|---|
| JP (1) | JPS5327528U (en) |
| BE (1) | BE857205A (en) |
| CA (1) | CA1058255A (en) |
| FR (1) | FR2361259A1 (en) |
| GB (1) | GB1537997A (en) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS609092Y2 (en) * | 1978-11-28 | 1985-04-01 | 株式会社小松製作所 | Inching brake control circuit for hydraulically driven vehicles |
| JPS5822247A (en) * | 1981-07-31 | 1983-02-09 | Toshiba Corp | Wind-up device for continuous lengths |
| DE10147852A1 (en) * | 2001-09-27 | 2003-04-10 | Zahnradfabrik Friedrichshafen | driving device |
Family Cites Families (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3201179A (en) * | 1963-05-13 | 1965-08-17 | Royal Industries | Emergency device for pneumatically operated brakes |
| DE1430666C3 (en) * | 1964-11-27 | 1975-12-04 | Robert Bosch Gmbh, 7000 Stuttgart | Braking device for vehicles |
| DE2008052A1 (en) * | 1970-02-21 | 1971-09-02 | ||
| US3988893A (en) * | 1972-04-28 | 1976-11-02 | Eaton Corporation | Hydrostatic transmission drive system |
| US3854559A (en) * | 1973-10-01 | 1974-12-17 | Deere & Co | Control system for a hydraulically-operable brake and transmission |
| US4033631A (en) * | 1975-11-24 | 1977-07-05 | Caterpillar Tractor Co. | Brake control mechanism |
-
1977
- 1977-03-29 GB GB1310077A patent/GB1537997A/en not_active Expired
- 1977-05-24 CA CA278,976A patent/CA1058255A/en not_active Expired
- 1977-05-25 JP JP6642577U patent/JPS5327528U/ja active Pending
- 1977-07-19 FR FR7722079A patent/FR2361259A1/en active Pending
- 1977-07-27 BE BE179674A patent/BE857205A/en not_active IP Right Cessation
Also Published As
| Publication number | Publication date |
|---|---|
| BE857205A (en) | 1978-01-27 |
| FR2361259A1 (en) | 1978-03-10 |
| JPS5327528U (en) | 1978-03-09 |
| GB1537997A (en) | 1979-01-10 |
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